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Master’s Speciality: DIT

Hamed Beigi

2020-2021

Plastic at the service of nature

Director:

Elisabet Quintana Vilajuana

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Table of Contents

Abstract ................................................................................................................................................................................................ 1

Introduction ........................................................................................................................................................................................ 1

Problem statement ............................................................................................................................................................................. 4

Methodology ....................................................................................................................................................................................... 4

CHAPTER ONE ................................................................................................................................................................................... 4

Plastic .................................................................................................................................................................................................... 4

Plastic in depth ................................................................................................................................................................................ 2

Degradation mechanisms of plastics .............................................................................................................................................. 4

Abiotic degradation of plastics .................................................................................................................................................... 5

Photodegradation of plastics ....................................................................................................................................................... 5

Biotic degradation of plastics ...................................................................................................................................................... 5

Type chapter title (level 2) ............................................................................................................................................................ 5

Hydrophobicity ................................................................................................................................................................................... 4

Biofilms ................................................................................................................................................................................................. 4

Microbial Biofilms formation ........................................................................................................................................................ 5

result ................................................................................................................................................................................................ 5

CHAPTER TWO ................................................................................................................................................................................. 4

Plastic application .............................................................................................................................................................................. 4

Commodity of plastics ................................................................................................................................................................... 5

Circular economy & Closing the loop ........................................................................................................................................... 4

Discarded plastic operation in circular economy approach .................................................................................................. 5

Recycling ......................................................................................................................................................................................... 5

Collection of materials .................................................................................................................................................................. 5

Washing ........................................................................................................................................................................................... 5

Drying .............................................................................................................................................................................................. 5

Pelletizing ......................................................................................................................................................................................... 5

Grinder .............................................................................................................................................................................................. 5

Extruders .......................................................................................................................................................................................... 5

Cooling .............................................................................................................................................................................................. 5

Melt Flow Rate Testing ................................................................................................................................................................ 5

Tensile testing ................................................................................................................................................................................. 5

Diameter tolerance and Filament roundness ............................................................................................................................ 5

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Additive manufacturing ................................................................................................................................................................... 4

3D printing methods ...................................................................................................................................................................... 5

Materials extrusion method ......................................................................................................................................................... 5

Plastic extrusion ................................................................................................................................................................................. 4

Recycled plastic filament ................................................................................................................................................................. 4

Preparing material for 3D printing .............................................................................................................................................. 5

Plastics .............................................................................................................................................................................................. 5

Polypropylene (PP) ......................................................................................................................................................................... 5

Polyethylene (PE) ............................................................................................................................................................................ 5

Extrusion equipment ...................................................................................................................................................................... 5

Result ................................................................................................................................................................................................ 5

CHAPTER THREE ............................................................................................................................................................................. 4

Installation ........................................................................................................................................................................................... 4

Installation art out of plastic waste & Precedents ................................................................................................................... 5

BioInstalation ..................................................................................................................................................................................... 4

Ecosystem services ........................................................................................................................................................................ 5

Role of biodiversity in ecosystem services ................................................................................................................................ 5

Value deconstruction of BioInstallation ..................................................................................................................................... 5

Customers & Stakeholders .............................................................................................................................................................. 4

User ................................................................................................................................................................................................... 5

Business model plan .......................................................................................................................................................................... 4

Digital presence .............................................................................................................................................................................. 5

Type chapter title (level 2) ............................................................................................................................................................ 5

BioInstallation as a wetland ............................................................................................................................................................. 4

Case studies analysis ....................................................................................................................................................................... 4

Rotterdam's floating park .............................................................................................................................................................. 5

Urban Aquatic Health .................................................................................................................................................................... 5

Natural swimming pool.................................................................................................................................................................. 5

CHAPTER FOUR ............................................................................................................................................................................... 4

Design route ...................................................................................................................................................................................... 4

Prototype design process ................................................................................................................................................................ 4

The digital system ............................................................................................................................................................................... 4

The digital outcome of the prototype ........................................................................................................................................... 4

Conclusion .......................................................................................................................................................................................... 4

References ........................................................................................................................................................................................... 4

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چکیده

این پژوهش .انسان شناخته شده استتولید ، استفاده و دفع پلاستیک یکی از نگرانی های اساسی و جهانی است و به عنوان مسئله زیست محیطی و سلامت

انجام می ارتقاء خدمات اکوسیستم بکارگیری پسماند پلاستیک مناسب در جهت امکان بررسی روش شود.به منظور آشکار ساختن بکارگیری با نوین های

آوری اطلاعات ها تبیین می گردد، در مرحله جمعوش های بازیافتی حوزه تاثیر و امکان ارتقاء خدمات اکوسیستم و افزایش تنوع زیستی توسط این رپلاستیک

با توجه به بررسی فرآیندهای بازیافتی، ای و بررسی نمونه موردی استفاده شده است. روش تحقیق مورد استفاده در این پژوهش کیفی است.روش کتابخانه

باز طراحی با حداقل هزینه، انرژی ((Circular economyد دایره های زیست محیطی و اقتصادی ، بهترین روش بکارگیری پلاستیک از طریق اقتصاچرخه

شده توسط طراحان به منظور ارتقاء توان اکولوژیکی های محیط زیستی است، که با بکارگیری، بازطراحی و تولید مجدد در ساختارهای طراحی و ایجاد آلودگی

ری فرآیندهای بازیافت پلاستیک از اهمیت بسزایی برخوردار است. در نتیجه این تحقیق در ودر کشورهای پیشرفته بهرهعلاوه بر این، محیط صورت میپذیرد.

های دورریخته شده و استفاده از وری و حذف فرآیندهایی که نیازمند صرف منابع است، روشی نوین برای طراحی با پلاستیکتلاش است با افزایش بهره

ساختار تالاب های مصنوعی شناورارائه دهد. تکنولوژی چاپ سه بعدی به عنوان متریال طراحی

، محیط زیست، تنوع زیستی خدمات محیط زیستیکلید واژه ها: بکارگیری پسماند پلاستیکی، تولید افزودنی،

Abstract:

Production, usage, and disposal of plastic is one of the fundamental and global concerns and has been known as an environmental and human health issue. This research is going to disclose the possibility of using suitable waste plastic in order to improve ecosystem services. This research proposal primarily will be based on considering new innovative modules of taking advantage of discarded plastics in the scope of impact and the possibility of improving ecosystem services and increasing biodiversity. The information-gathering will refer to the literature reviews and case studies analysis and considering qualitative research in the research method. Regarding the study of the recycling process, ecological and economic loops, the circular economy will be recognized as the best approach for reusing, redesigning, and remanufacturing architectural structures that are made of waste plastics in order to improve the ecological potential of the environment via designing constructed wetlands by designers at the lowest possible cost, energy, and environmental pollution. Furthermore, the efficiency of plastic recycling processes is extremely significant in developed countries. As a result, this study attempts by increasing efficiency and eliminating the processes that will consume valuable resources, to provide an innovative method of design by taking advantage of discarded plastics through additive manufacturing, as a using material for constructing floating artificial wetlands.

Keywords: Reusing plastic waste, additive manufacturing, ecosystem services, environment, biodiversity

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Introduction:

Literature reviews

Plastic is one of the most significant and widespread materials in our economy and daily lives. However, the technique and approach of recycling plastic that is currently produced, used, and discarded fails to capture the economic benefits of a more 'circular' approach and harms the environment.[1] According to Ellen MacArthur Foundation, yearly more than 8 million tons of plastic entering the ocean. Affordance, lightness, and versatility are the most assets of plastic which encompasses our economy as a dominant material, however, only 14% of all plastic packaging is collected for recycling after use, and vast quantities escape into the environment. If this condition continues, has a significant global economic consequence in a loss of $80 billion to $120 billion per year, and this results there could be more plastic than fish by weight in the oceans by 2050.[2] So, This is where adopting and implementing a circular economy model for waste plastic is important.

Light and innovative materials in cars or planes save fuel and cut CO2 emissions. High-performance insulation materials help us save on energy bills.[1] Combined appropriate discarded plastic for the marine environment with 3D printer equipment can conserve terrestrial and aquatic species in an environmental urban water fountain, pond, lake, harbor, and even home water fountain and outdoor pools. Production, usage, and disposal of plastic is one of the fundamental and global concerns and has been known as an environmental and human health issue. These potential problems include plastic debris in dwelling-places, physical problems for wildlife that have resulted through ingestion, entanglement in plastic, and the potential leaching of chemicals from plastic products to wildlife and humans.[3]

Biodiversity encompasses all terrestrial and freshwater species, and changes in land use are one of the most significant causes and determinants of biodiversity changes on a global scale.[4] Rapid urban growth has resulted in a critical issue and a generative area of conservation due to dramatic changes in urban natural habitats and species deprivation caused by urban and suburban development, as well as an elevated abundance of species in urban environments. [5]

The fragmentation of natural habitats and the development of an integrated landscape in urban areas, in several ways, cause the uniformity of life and reduce plant and animal biodiversity that making consequences like;

1. Reduction and elimination of native species by changing land use (As a result, it puts pressure on the relationship between humans and nature)

2. Introducing and adding invasive non-native species through habitat disturbance and human intervention.[5]

Converting natural landscapes into urban areas is a common change that can be resulted in the reduction and elimination of freshwater habitats, as well as, weakening existing habitats and also puts a lot of pressure on plant and animal species. Where extensive land development has already occurred, native animal biodiversity can be enhanced by revegetation using a diverse range of native plant species.[6]

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Recent mechanistic investigations show that urbanization alters animal behavior, morphology, and population dynamics. Controlling invasive species in favor of native species requires a better knowledge of the ecological and evolutionary processes taking place in urban and other human-dominated regions. Figure-1 shows the connections between human activity and patterns of population density and species diversity.[5]

Fig-1: Pathways via which human activities influence the biological structure of urban environments

Due to the growing rate of urbanization, particularly in developing countries, a greater knowledge of urban ecosystems is critical to biodiversity conservation in general. The interaction of humans and urban freshwater ecosystems serves as a model case study for the interaction of natural and anthropological processes (Fig-2).[8]

Fig-2: A variety of interconnected variables influence urban aquatic biodiversity. Legal influence is shown by red dotted boxes

The present reliance on consuming and recycling plastic is not sustainable. The massive amount of garbage and wasted plastic in landfills has prompted humanity to reconsider recycling options. There are several viable options, that are easier to implement than others. These include material reduction, end-of-life recyclability design, increased

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recycling capacity, bio-based feedstock development, debris reduction approaches, and improved risk assessment procedures.[3]

Nowadays, additive manufacturing plays an important role in technology and now has the potential to influence our future through the utilization of alternative materials. A wide range of materials from concrete, plastic, resins, clay and even biomaterials, any elements ranging from bricks to entire buildings can be printed (e.g. CIM UPC, 2021).[9]

This master's thesis focuses on how to use discarded plastic to construct the floating artificial and architectural structure in an environmental urban water fountain, pond, lake, and harbor or home water fountain and outdoor pool to create a circular economy through additive manufacturing and increase biodiversity in order to improve ecosystem services.

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Problem Statement:

Why;

Every year we observe the accumulation of discarded plastic in urban areas and face plastic debris and landfills in natural habitats, that causes contaminate our planet. It is evident that the process of recycling waste plastic requires lots of money and energy to construct recycling facilities, reprocessing plants, employees, workers, and Vehicles for transporting trash. One of the problems in metropolitan cities and their lakes, ponds, harbors, or artificial reservoir basins in environmental urban areas is a lack of biodiversity, as well as the increasing possibility of water contamination, climate change, and the deprivation of terrestrial and aquatic species, that what endangers wildlife and human health.

On one hand, It is estimated that plastics production and the incineration of plastic waste give rise globally to approximately 400 million tonnes of CO2 a year. Reuse and recycling of end-of-life plastics tend to be extremely low, especially when compared to other materials such as paper, glass, or metals.[10] Once the plastic has been collected and sorted, it faces a weak market. Simply collecting plastic does not mean that there will be a buyer willing to pay for the raw material. Making plastic containers from fresh, nonrenewable materials is frequently less expensive and easier. Plastic recycling, unlike glass or metal recycling, does not “close the loop” since most post-consumer bottles are not recycled into new plastic bottles. Toxins and carcinogens can move from plastic containers to food and beverages within the container, especially when the plastic is heated. Moreover, despite attempts to keep emissions pure, plastic incineration pollutes the air, land, and water.[11] In open-loop recycling, also known as ‘downcycling’, the quality of recycled material may be lower than that of its original product, due to erosion of the plastic properties.[12] According to Plastics Europe, about 25.8 million tonnes of plastic waste are created in Europe each year, with less than 30% of this waste being collected for recycling.[1] Spain's share of this amount is 2.3 million tonnes of plastic in 2016. EAE's report concludes that, in Spain and its autonomous communities, 56.7% of waste is dumped in landfills and that is lower than the average of the European Union.[13]

On the other hand, in case this project will be launched up in Spain, has almost 500 reservoirs and lakes,[14] in addition, lakes and ponds, are one of the landscape elements that contribute significantly to raising the expectations for a decent life in urban areas by improving amenity, offering recreational and educational activities, and even helping to moderate the urban climate. Furthermore, contemporary metropolitan areas have a major impact on the quality of these aquatic ecosystems. Since the watershed of these ecosystems is part of the urban body, they tend to highlight the environmental concerns that impact metropolitan areas by gathering and depositing significant amounts of nutrients and pollutants, including microbiological contaminants. Fecal pollution, as well as a wide range of poisonous cyanobacteria and stinky blooms, may damage the biological value of these habitats, spawn vermin, and turn them into a possible risk to human health, requiring costly management and restoration strategies.[15]

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How;

Overview of BioInstallation

When we are talking about the BioInstallation it comes up to design an architectural and artistic installment, structure, or pontoon by taking advantage of discarded plastic, through additive manufacturing (3D printer technology) that contribute to creating a potential opportunity of increasing biodiversity and improving ecosystem services in an environmental urban like a water fountain, pond, lake, harbor, artificial reservoir basin, or home water fountain and outdoor pool.

Aim

Design sustainable and high-perfuming floating wetland with gaining leverage of regarded plastic that markedly contributes as a hazardous and malicious substance to the environment and dwelling places, to reuse them cost-effectively and sustainably as a circular economy through utilizing additive manufacturing to conserve natural habitats, enhance ecosystem services and social engagements.

Objectives of dissertation

• Research what type of plastic waste is proper and compatible for marine environments • Present production recycled printing filament by plastic waste • Collection way of suitable plastic materials • Analyze stakeholders, branding, the business model canvas of BioInstallation, and prototyping • Generate a systematic & geometric floating prototype • Digital outcome renderings of prototype

Research question

How can an alternative recycling system be created for discarded plastic to lead ecosystem services in urban water environments by utilizing additive manufacturing?

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Methodology

This proposal is based on a knowledge-oriented or design-led approach. The strategy of this research will utilize the four steps through "design thinking" (Fig-3) to answer the main research question and also set upcoming research questions along with the dissertation. These steps are including; Define, ideation, Prototype, and Design outcome

The problem is clearly defined in the problem statement as well as the implication and need of urban ecology in the introduction part, so the first step will start with a literature review to introduce plastic, Finally, further research into what types of plastic would be proper for marine environments will conclude this step.

The ideation step will evolve an introduction of "closing the loop" and "circular economy" and exploration of the new innovative module of recycling plastic waste through circular economy contribution to a freeform 3D printer, and a presentation diagram of recycled plastic filaments out of waste plastic.

The third step, will define BioInstallation and discuss the general view of the prototype, branding, and business model more explicitly and clearly. Case studies analysis is part of this step to identify the framework and construction aspects of the structure. Lastly, the fourth step will indicate prototype, will represent a solution from using achieved information of the previous stage through the digital design .e.g. Rhino, Grasshopper and then an illustration of getting inspiration and primary concept and sketch of the design process and finally the digital design outcome by taking into consideration of refining idea.

Fig-3: Design thinking steps

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CHAPTER ONE

Introduction

This chapter of the dissertation introduces plastic and discusses any aspects of environmental impacts on plastic's chemical and physical properties in marine environments and as well, will answer the research question in this part and reflect with the conclusion.

Research question: which type of discarded plastic is suitable for this project in a marine environment?

Chapter overview: • Introduction to plastic • Degradation mechanisms of plastics • Hydrophobicity • Biofilms

Literature reviews

1. Plastic Plastics are one of the most widely utilized materials on the planet. Plastic, as its name implies (from the Greek plastikos, which means "capable of being moulded or molded"), can take on any shape or form. That is why it is utilized in such a wide range of applications, from single-use items like packaging and bottles to long-lasting items like furniture, clothing, construction materials, and automobile components. Plastics have largely supplanted conventional materials such as glass, steel, wood, and even concrete. Plastics are lighter, less expensive, and have superior technical characteristics.[16] Plastics have brought a lot of benefits to modern life, driving the tremendous growth in plastic demand, because of their low cost, lightweight, and durable character. According to reports, 3 billion tons of plastic were created in 2016, and around 8 million tons of plastics enter the maritime environment each year. One of the implications of this buildup in the marine environment is the low proportion of recovered plastics, with just 9.4 million tons of plastic post-consumer waste collected for recycling in Europe in 2018. (both inside and outside the Europe). Plastic waste is already a problem in the oceans. Concerningly, it is predicted that by 2050, the weight of plastics in the water would exceed that of fish. 1.1. Plastic in depth

Microplastics (MPs) are plastic fragments or particles with a diameter of less than 5 mm formed by the fragmentation of larger plastics. Plastics can fragment into smaller particles in the marine environment. Microplastics come in a variety of forms, including foils, foams, fibers, pellets, pieces, and microbeads. Plastics are chemically varied in general. Polyamide (PA), polyvinylchloride (PVC), and polyethylene terephthalate (PET) have higher densities than seawater, which increases sediment settlement rates, whereas polystyrene (PS), high-density polyethylene (HDPE), low-density

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polyethylene (LDPE), polypropylene (PP), and polyurethane (PUR) have lower densities and may float primarily on seawater.[17]

2. Degradation mechanisms of plastics

Generally, conventional plastic materials are extremely resistant to deterioration. Polymers have been anticipated to survive hundreds or even thousands of years, depending on the characteristics of the plastics and the surrounding environmental circumstances. Environmental weathering causes the degradation of plastics, which causes changes in polymer characteristics owing to biological and/or abiotic processes, however at a very slow rate. Figure 4 illustrates the general stages of plastic breakdown.[18]

Fig-4. A schematic diagram showing the general processes involved in the degradation of plastics.

2.1. Abiotic degradation of plastics

The change in physical or chemical characteristics of plastics caused by abiotic elements such as light, temperature, air, water, and mechanical forces is referred to as abiotic degradation. Because plastics have low bioavailability, the abiotic breakdown is predicted to come before biodegradation. 2.1.1. Photodegradation of plastics

Photodegradation is characterized as one of the most significant mechanisms that begin plastic deterioration in the environment. Plastic photodegradation typically includes free radical-mediated processes triggered by sun irradiation. High energy ultraviolet (UV) irradiation UV-B (290–315 nm) and medium energy UV-A (315–400 nm) are mostly to cause.[18] Photo-degradation is the process of material breakdown caused by the action of light, and it is regarded as one of the major sources of damage to polymeric substrates under ambient circumstances. The majority of synthetic polymers are vulnerable to ultraviolet (UV) and visible-light-induced degradation. Normally, the lifespan of polymeric materials in outdoor applications is determined by the near-UV radiations (400–290 nm) in sunshine. The energy of the near-UV light quanta (400–290 nm) ranges from 3.1 to 4.3 eV, corresponding to 72–97 kcal/mol. This indicates that these UV quanta have energy for breaking the most chemical bonds. Photo and thermal deterioration are comparable under normal settings.[19]

Polyethylene (PE) is resistant to photodegradation, because of the lack of chromophores; nevertheless, the presence of impurities or structural flaws in polymers during production or weathering can serve as chromophores.

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Chromophores can be formed by carbonyl groups in the PE backbone. Radicals, end-vinyl, and ketone groups are generated during the Norrish Type I and II reactions, resulting in a main-chain scission. When free radicals combine with oxygen, they form peroxy radicals, which are then transformed into a peroxide moiety by hydrogen abstraction. The peroxide molecule splits into macro-alkoxy and hydroxyl radicals, which catalyze the next chemical sequence. During the reaction sequence, aldehydes, ketones, carboxylic acids, esters, and alcohols can be generated, as well as chain scission and polymer cross-linking. PP is less stable than PE, since the presence of tertiary carbon, which is more vulnerable to oxygen attack. Photodegradation processes of PP are identical to PE. The presence of chromophores in PP owing to impurities causes radicals to develop when exposed to UV light. Following radical mediated reactions, random chain scission and cross-linking occur, and lower molecular weight breakdown products are often produced.

2.2. Biotic degradation of plastics

The degradation of plastics induced by organisms is referred to as biotic degradation of plastics. Plastics can be degraded physically via biting, chewing, or digestive fragmentation, or biologically by biochemical reactions. Microorganisms such as bacteria, fungus, and insects are thought to be primarily responsible for the biological breakdown of plastics.[18] Biofilms (will discuss in following) are sessile colonies of microorganisms that form on a surface and might contain individuals from the same or distinct species. Complex biofilm communities made up of various bacteria have been discovered on polyethylene surfaces after being exposed to various biotic conditions. According to research on microbe attachment to polyethylene, the major restriction of the colonization process is the polymer's comparatively high hydrophobicity in comparison to the typically hydrophilic surfaces of most bacteria. It has been reported that strains with more hydrophobic surfaces might play a significant influence in the polymer's early colonization. Abiotic breakdown of plastics, which produces low molecular weight degradation products and forms cracks and holes on the polymer surface, can speed up biodegradation processes.[19]

Plastics are classified as hydrolysable or non-hydrolysable based on the presence or lack of ester or amide groups, which can be attacked by a variety of extracellular hydrolases. Extracellular enzymes can have a more difficult time degrading non-hydrolyzable polymers including PE, PP, and PVC. Because of their structural similarities, non-hydrolyzable polymers resemble lignin. As a result, enzymes engaged in the biodegradation of lignin may also contribute to the biodegradation of non-hydrolyzable polymers. Laccase was recently found to have an important role in the biodegradation of PE by the actinomycete Rhodococcus ruber. It was discovered that Azotobacter beijerinckii is responsible for the biodegradation of PS via hydroquinone peroxidase. It has also been proposed that various enzymes secreted by fungus can shorten the length of PE polymer chains. Non-hydrolyzable polymers can be oxidized by O2 via the catalysis of such enzymes, resulting in the production of low molecular weight breakdown products.[18]

Since the PE surface is hydrophobic, it has been proposed that the more hydrophobic the bacterial cell surface, the greater the contact with the PE. The creation of surfactants, which are chemicals that can facilitate the attachment process of microbes to the hydrophobic surface, is another metabolic adaption that might be essential in polymer colonization. According to Harshvardhan and Jha, marine microbes, or microorganisms, employ the PE surface as a carbon source. This is the initial stage in the biodegradation of PE, and it results in a decrease in molecular weight. Once the molecule's size is reduced, oxidation is necessary to convert the hydrocarbon into a carboxylic acid that may be metabolized via β-oxidation and the Krebs cycle.

In nature, polyolefin degradation is a very gradual process that is begun by environmental conditions and then followed by microorganisms. Although PP is extremely hydrophobic with a high molecular weight, without active functional groups, and has a continuous chain of repeating methylene units, since biofilm development or microbe

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adhesion to PP is very poor, it is resistant to biodegradation. To make polyolefins biodegradable, the hydrophilic levels must be increased or the polymer chain length must be reduced by oxidation to allow for microbial decomposition. Several types of research have been conducted in order to enhance these characteristics and assess the influence of additives on the biodegradation process. UV, heat, and chemical treatments all-cause oxidation of the polymer surface and the production of carbonyl, carboxyl, and ester functional groups. This reduces the surface's hydrophobicity and so promotes biodegradation. There has been little research on the biodegradation of PP.

Hydrolyzable polymers such as PET, PA, and polyurethane (PUR) are often more vulnerable to biodegradation, because of the existence of established biodegradation routes such as extracellular hydrolases involved in the breakdown of cellulose and proteins.[18]

3. Hydrophobicity

In Fig. 3, hydrophobicity was quantified using molecular-level methods that included theory, modeling, and experimental validation. Pharmaceutical advancements in estimating the solubility of drug-like compounds using computational octanol-water partition coefficients inspired the model (LogP). The LogP equation in Fig-3 (a) accommodates for both negative and positive values. Negative LogP values predict water solubility, polymers that swell in water, or polymers that absorb water, whereas positive values suggest insolubility in water. Using molecular dynamics (MD) simulation to reduce the energy of molecular models, followed by surface area (SA) calculation, may be compared various polymers.[20]

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Fig-5. Plastics cover a wide range of hydrophobicity. a Flow chart for calculating hydrophobicity, b range of LogP(SA)−1 values for various plastics

4. Biofilms

Microbial biofilms are colonies of aggregated microbial cells that are embedded in a self-produced extracellular polymeric matrix (EPS). Biofilms are resistant to harsh conditions and may shield bacteria from ultraviolet (UV) radiation, excessive temperature, extreme pH, high salt, high pressure, inadequate nutrition, antibiotics, and other abrasives by functioning as "protective clothing." In recent years, biofilm research has mostly focused on biofilm-associated illnesses and techniques for controlling microbial biofilms.[21] The “bottle effect” for marine microorganisms was seen, for instance, the incorporation of a surface to which these organisms might adhere significantly increased bacterial growth and activity.[22] Bacillus subtilis biofilm is an architecturally sophisticated, extremely hydrophobic community that is resistant to wetting by water, solvents, and biocides.[23]

A biofilm is an organized collection of bacteria living inside a self-produced matrix of extracellular polymeric substances (EPS) adhering to an abiotic or abiotic surface. It is regarded as one of the most extensively distributed and effective ways of life on the planet.[21] Biofilms in the environment can host human infectious pathogens, but they can also assist in the remediation of contaminated groundwater and soils. They help in metal mining and play a crucial natural role in the recycling of materials on Earth.[24]

4.1. Microbial Biofilms formation

Based on prior research, the biofilm lifestyle is an infinite cycle, and the process of biofilm development may be described into the five key stages listed below. Fig-6: (I) Adsorption: Microorganisms are reversibly adsorbed to a surface via weak interactions (such as van der Waals forces) with a biotic or abiotic surface; (II) Colonization: Microorganisms are irrevocably connected to the surface via greater hydrophilic/hydrophobic interactions mediated by flagella, pili, lipopolysaccharides, exopolysaccharides, collagen-binding adhesive proteins, etc; (III) Development: multilayered cells proliferate and EPS is generated and released; (IV) Maturation: stable development of a three-dimensional community with channels to effectively transfer nutrients and signaling chemicals within the biofilm; (V) Active dispersal: microbial cells are detached in clumps or separated as a result of interactions with either intrinsic or extrinsic factors, and the scattered cells colonize various locations. [21]

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Fig-6. Microbial biofilm development model. There are five main phases in the development of a biofilm: I. Attachment: Microbial cells reversibly cling to the surface. II. Colonization: Microbial cells irreversibly adhere to the surface via flagella, pili, exopolysaccharides, etc. III. Growth: multilayered cells collect and generate extracellular polymeric molecules (EPS). IV. Mature: the creation of a three-dimensional community that is stable. V. Active dispersion occurs when microorganisms are dispersed from the aggregate biofilm and revert to a planktonic condition.

Result

According to the studies have done in this research, among the discarded plastics, PP and PE are included for further study due to their higher density than water. Given the physical and chemical characteristics of PE and its resistance and durability to biodegradability and photodegradation and low hydrophobicity of this material to form microorganisms such as biofilms for growth and development of other Species composition that is most often heterogeneous and may even encompass fungi, algae, and protozoa. Furthermore, the distinct physiology of biofilms is increasingly recognized as being critical in many parts of nature and business. According to the findings on biofilm and its productive effects on humans and nature, they provide colonization resistance to infection, assist in nutrient absorption from the intestine, and treatment to purify stagnant waters of urban ponds and lakes in order to attract aquatic and terrestrial species that contribute to increasing biodiversity.

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CHAPTER TWO

Introduction

This chapter of the dissertation introduces precisely plastics according to the research question reflected in the previous chapter and verifies recycling plastic approaches through the circular economy and as well as will discuss recycled filament production out of discarded PP and PE and their requirements. Furthermore, it should be noted that due to time, financial, expert constraints, and other limitations in the experiment all contents and pictures in this following chapter are based on literature reviews and real experimental work of other authors.

Chapter overview:

• Plastic application • Circular economy and Closing the loop • Additive manufacturing • Plastic extrusion • Recycled plastic filament

Literature reviews

1. Plastic application

Plastics are a broad category of synthetic or semi-synthetic materials made mostly of polymers. Plastics may be molded, extruded, or pressed into solid objects of diverse forms due to their fluidity. Its widespread use is due to its adaptability, as well as a variety of other characteristics such as being lightweight, resilient, flexible, and affordable to make [25] and It is also versatile, moisture-resistant, and stiff. These are the appealing features that have led to an insatiable hunger for plastic items and overconsumption all over the world. Plastic materials, which are robust and slow to deteriorate, are employed in the manufacturing of a wide range of materials, but they all eventually fade away and become waste with a limited life span.

1.1. Commodity of plastics

A broad range of plastics raw materials is developed to meet the material demands of various sectors of the economy. Service, engineering, and specialty plastics are the broad categories for these polymeric materials. Commodity plastics are the most significant items in the plastics business, and hence in the petrochemical sector. Polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and polystyrene are examples of commodity plastics (Table-1). While engineering and area of expertise plastics have excellent mechanical and thermal characteristics in a wide range of circumstances, they are used for a particular function.

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Group Recovery

rate Typical application Additional

information Plastic recycling

symbols

Polyethylene terephthalate (PET) 27%

Fiber (clothing, carpet), film (balloons, packaging, thermal sheets, adhesive backing), bottles (pop, water), cosmetics packaging and food containers, transparent containers microwavable packaging

Clear, firm, and lightweight

High-density polyethylene (HDPE)

31%

Non-food containers (laundry detergent, shampoo, conditioner, and motor oil bottles) plastic lumber, Milk, water and juice containers, ice cream containers, bottle caps, milk jugs, and molded plastic cases, buckets, crates, flower pots, film, recycling bins, and floor tiles.

Stiff and resilient, and it's hard to break down in sunlight.

Polyvinyl chloride (PVC)

3%

Bottles with handles, plumbing pipes and guttering, electrical wire/cable insulation, shower curtains, loose-leaf binders, decking, paneling, gutters, mud flaps, window frames, and flooring and garden hoses and mobile home skirting

Plasticizers can make it stiff or soft. Chemical characteristics make it difficult to recycle.

Low-density polyethylene (LDPE)

7%

Shopping bags, bread bags, frozen food bags, and dry-cleaning bags, plastic sheeting, packaging film and sheeting, wrapping film, outdoor furniture, siding, floor tiles, shower curtains, and clamshell packaging

Lightweight, inexpensive, and adjustable. It is difficult to recycle due to failure under mechanical and thermal stress.

Polypropylene (PP) 18%

Automobile battery boxes, fenders and bumpers, signal lights, brooms, oil funnels, brushes, ice scrapers, condiment bottles, margarine containers, yogurt containers, bicycle racks, and rakes, food containers, bottle caps, drinking straws, yogurt containers, appliances, and plastic pressure pipe systems.

Tough and robust; efficient barrier in against water and chemical . Frequently unrecyclable.

Polystyrene (PS) 2%

Thermometers, light fixtures plates, heat resistance, food-service applications, grocery-store meat tray, egg cartons, cups, plates, fresh product containers, large packaging, foam peanuts, food containers, plastic tableware, disposable cups, plates, cutlery, compact disc (CD) and cassette boxes

Weak structurally and readily distributed. It is almost never recycled.

Other (Multi-product/layer)

2%

Polycarbonate (refillable plastic bottles, metal food can liners, consumer electronics, lenses); nylons (clothing, carpets, gears); biodegradable resins (food and beverage packaging); mixed plastics and blends (electronics housing, plastic lumber), and other materials Particularly in the technical fields.

The variety of materials poses a danger of contamination of recycling.

Table-1. The standard category of commodity and recycling symbols of plastics

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Low-density Polyethylene (LDPE), High-density Polyethylene (HDPE), and Linear Low-density Polyethylene (LLDPE) are the three main kinds of PE. PE and PP are major plastic materials made from ethylene and propylene, respectively, whereas PVC, PS&ABS, and PC are made from benzene, butadiene, and other feedstock. Packaging is the most common use of plastics in the food industry(Fig-7).[26]

Fig-7. The product wise breakup of plastic products

2. Circular economy & Closing the loop

Producing a huge volume of plastic waste, which has a significant influence on our environment, is critical to prevent and reduce the damage that waste can do as much as possible. It is also mandatory to take into consideration how we might develop new techniques and technologies to meet the objective of maximizing the value chain of products and services.[27]

The circular economy (CE) concept is a solution to environmental and social concerns, replacing the traditional linear approach based on the "take–make–dispose" model. The adoption of another economic closed-loop system, based on the principles of the 3Rs: Reduce, Reuse, and Recycle, was pushed by rapid urbanization, intense resource consumption, and unmanaged environmental damage. Three more techniques are included in the wider methodology (Fig-8): Recover, redesign, and remanufacture are all terms used to describe the process of recovering, redesigning, and remanufacturing.[28]

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Fig-8. The basic concept of circular economy

Some of the most relevant theoretical definitions are cradle-to-cradle, industrial ecology, biomimicry, regenerative design, laws of ecology, looped and performance economy, and the blue economy.[29]

The ‘cradle to cradle' concept, developed by William McDonough and Michael Braungart, focuses on products and materials that are safe for human health and the environment. Instead of being dumped to the 'grave,' they proposed categorizing things as biological or technological nutrition (Fig-8). When an animal's 'waste' produces nutrients for fungus and plants, this is an exemplification of biological nutrients. When a product, such as metal or plastic, may become "food" for another product/s, this is referred to as technical nutrition. Another author, architect Walter Stahel, works toward four major objectives: product life extension, long-life goods, reconditioning operations, waste reduction, and selling services rather than products. Author Janine Benyus describes biomimicry as "a new field that analyzes nature's greatest ideas and then imitates these designs and processes to address human challenges." The circular economy takes these concepts and applies them to nature, using natural processes to assist us to solve our problems. John T. Lyle proposes the concept of regenerative design, which is believed to be the circular economy's foundation.[30]

Fig-9. Two approach models of cradle-to-cradle concept

The concept of laws of ecology was taken from "The Closing Circle," which was innovative when it was published in 1971 and whose message continues to be relevant today. The founder of contemporary ecology, Barry Commoner, contends that profit-driven production has severe ecological consequences and provides a clear explanation of

22

nature, causes, and potential remedies to approaching ecological calamity.[31] Stahel introduced the notion of a looping and performance economy, which describes techniques and models for using technology and information to improve performance, generate employment, and enhance wealth. It demonstrates what abilities and skills will be necessary to create, market, and control performance through time, as well as how physical labor may help to minimize non-renewable resource usage.[32] Finally, the blue economy was conceived as a project to identify 100 of the top nature-inspired technologies that might have an impact on global economies while supplying fundamental human necessities such as drinkable water, food, work, and livable shelter in a sustainable manner. Dr. Pauli and his colleagues combed through 2,231 peer-reviewed publications to find 340 breakthroughs that might be packaged into ecosystem-like systems. Then these were evaluated by a team of business strategists, professional financiers, and public policymakers.[33]

The Ellen MacArthur Foundation provided the most well-known definition: "A circular economy is built on the concepts of designing out waste and pollution, keeping goods and resources in use, and renewing natural systems."[34]

Circular Economy (CE) is an economic system on business models that through reducing, reusing, recycling, and recovering materials in production and consumption processes, has originated the replacement from 'end-of-life' concept to one which intends to create economic prosperity, environmental quality, and social equity. The core of the circular economy is based on being more independent of raw material for the production of products and it tries to reduce the environmental damage produced by huge residuals.

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Table-2. The R9 Framework (Source: www.all3dp.com)

Table-2 demonstrates the R9 framework, including all of the principles and their definitions. The gradations of circularity also clearly show that recovering energy from materials by incineration of residual flows is the last option for extracting value from resources. Originally, the linear economy was used, in which raw materials were withdrawn and waste material was generated after a single usage. As a result, a higher level based on recycling and energy recovery is an economy with feedback loops that are still not closed, allowing raw materials to enter and residuals to be generated.[35]

2.1. Discarded plastic operation in circular economy approach

Plastic processing and the manufacture of 3D printer filaments comply with the principles of the circular economy and have a major impact on the environment by minimizing anthropogenic pollution with plastics. The reuse of defective prints, used items, disposable prototypes, and waste materials that were not initially intended for 3D printing as a source of resources for filament manufacturing is advantageous both economically and environmentally (Fig-9). This lowers material prices as well as CO2 emissions and energy usage. By creating composites that comprise a polymeric matrix reinforced with fiber, ceramics, metal, or glass, additive manufacturing in polymers recycling can proceed with simultaneous improvement of materials' thermal, mechanical, and tribological characteristics. Thermal analysis (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), Fourier-transform infrared spectroscopy (FT-IR), and thermal conductivity are all techniques that may be used to study material degradation. Thermoplastic polymers can also be utilized to create composite materials that add value by enhancing the material's esthetic and mechanical properties.[28]

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Fig-9. Recycling scheme for 3D printing materials

There is a series of procedures that make up the complete cycle, according to the application of the circular economy concept to discarded plastic waste, Particularly PE and PP plastic wastes in this project. In this case, the mechanical recycling process entails repurposing plastic residues (post-consumer items) into new, similar, or completely different products. Mechanical recycling's primary objective is to create new products by reducing the usage of new raw materials through a mechanical process that is regarded to be the simplest and most basic recycling process. The steps generally consist of the following: Collection, Washing process, Drying, Grinding, Extruding, and 3D printing that all will be covered in detail in this following chapter. It will examine each operation in order to comprehend how it works and the other criteria that are involved.

2.1.1. Recycling

Recycling has benefited both humans and the environment to some level today, but there is still more to be done to improve. Plastic recycling, also known as reprocessing plastic, is the process of reusing waste or discarded plastic to create new goods that are either similar to or entirely different from the original. The first step in making recycling viable is to identify plastics. Three arrow triangular shapes with a number identifying the kind of resin/polymer used in the plastic are used as identification techniques. Formerly, Table-1 showed how the plastic is frequently shortened at the bottom triangle form indication. Other methods for identifying a plastic include burning tests, observation tests, and flotation testing.[36]

2.1.2. Collection of materials

In general, the collection step is used to gather all types of plastics into a single location for subsequent processing. polypropylene (PP) is one of the most common types of plastic waste. Within the recycling triangle, items manufactured of PP carry the universal identification number '5'. The resin identification coding system makes it simple to identify a product's plastic kind. These codes are used in recycling processes so that various polymer kinds may be recycled without contaminating one other. In the production of plastic items such as beverage bottles, PP is frequently mixed with PET. In this case, the 'sink/float' technique may be used to determine the plastic type. Since PP has a particular specific density, it floats whereas other polymers sink.[37] From another hand, different HDPE

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containers were gathered in a plastic bag (Fig-10). The majority of the materials gathered are from household items such as discarded shampoo bottles, detergent containers, cleaning agent bottles, and milk jars. In most cases, all types of plastic are gathered in one location for further processing. The gathered plastics were divided into two groups; (1) comparable plastics of the same color and (2) various colored plastics together. This classification was carried out to guarantee correct procedure and avoid contamination during post-processing.[36]

Fig-10. Collection of HDPE plastics

2.1.3. Washing

Washing operation is generally done to remove contaminants from plastic such as dust, grease, labels, oil, glue, and so on. They are cleaned using surfactants (detergents) or a solution of sodium hydroxide (NaOH). Depending on the post-processing needs and amount of contamination, the washing might be done before or after the plastics are shredded into flakes.[36] Speaking of wastewater in stage, reuse water in technical processes and wastewater reduction frequently need the development of new technologies. This will increase the initial expenses, but it will result in environmental and economic benefits in the long run as a result of the water savings. There is a great number of systems that are used to recycle water such as coagulation, membrane ultrafiltration, flotation, and other more innovative as photocatalytic treatment technology under artificial and solar illumination.[35] While gathered HDPE plastic washing, the plastic was immersed in 60°C water for around 5 hours to remove the labels and adhesive. Peeling the labels off by hand was used to remove them. Following that, they are sorted into comparable plastics of the same color, and the various plastics are assembled (Fig-11).

Fig-11. Soaked HDPE plastics, Similar washed plastics, and Mixed colored washed plastics, respectively

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2.1.4. Drying

The drying stage effectively requires enough heat to remove all moisture from the plastic, which is executed by utilizing a drying machine set to the material's specified drying temperature.

2.1.5 Pelletizing

The pelletization process involves utilizing an extruder to convert recycled HDPE and PP flakes into pellets (Fig-11,12). This was done to achieve regular particle sizes that would improve the output flow of molten plastic flowing out of an extruder and utilized for filament fabrication.[36] After shredding by a grinder (Fig-13), the plastic flakes are processed in an extruder to produce pellets. If polyethylene (PE) is recycled and processed to make pellets, the temperature zones of the extruder would be between 190 and 200°C. The processing is carried out following the material datasheet for the individual material.[36] Shredded plastic pellets will allow generating more steady filament and, as a result, a higher quality print, since turning shredded into plastic may also make it difficult to construct a thick enough filament or need other high-powered printers. Downcycling plastics may require the use of more additives than 'virgin' plastic. This is because once some plastics are melted or combined, the chains that make them strong and flexible shorten. Utilizing chemicals must be applied in order to get the desired performance of the filament plastic.[30]

Fig-11. Mixed colored HDPE flakes & Recycled HDPE pellets, respectively

Fig12. Recycled PP pellets

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2.1.6 Grinder

Industrial grinders are capable of shredding plastic waste collection into tiny chunks. Size reduction is the process of reducing the amount of waste in order to feed it directly into the hopper of an extrusion machine. The plastic shredder has a rotor with many blades that, because of the power and speed of rotation, cut the plastic into the desired flakes size. This activity is critical for converting potentially large solid material things into smaller items, which would enhance waste management and disposal.[35]

Fig-13. Isometric view of the plastic shredder

2.2 Extruders

Extruders are the machines that produce recycled plastic filament. They are used to make a variety of items from a specific type of plastic resin, including plastic tubing, trimmings, seals, plastic sheets, and rods. Screw extruders, the most common type of extruder, are classified into two types: single screw and multi-crew extruders. The first category is the most popular due to its basic designs, usability, resilience, and low cost. Twin-screw extruders, on the other hand, are more efficient when mixing diverse components such as additives, fillers, and liquids. Extrusion screw design has improved over the years in terms of final forms, with innovations and concepts that aid in constantly modifying the process to fit the demands of specific applications.

An extruder machine is made out of a barrel divided into three zones, each with a particular temperature. The polymer, which has previously been shredded into small pieces, is delivered into the barrel through a hopper. Following that, it raised the temperature of the material to the polymer melting point while passing through the temperature zones. Finally, the extrusion process pushes the material to the die zone, where it is molded into the required shape. The screw plays the most important role in the extrusion process, and it is composed of three major functional/geometrical zones: solids conveying, melting, and metering (Fig-14).[35]

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Fig-14. Schematic view of an extruder

Solids conveying/Feed zone: The pellets are fed into the furnace through the Feed zone of the screw. The purpose of this zone is to heat up and transfer the material to the next zone. As long as the material is solid and below the melting point, this will continue.

Melting/Compression zone: The melting of the pellets takes place in the compression zone, also known as the transition zone. The screw's depth steadily decreases in order to compress the plastic towards the barrel. This involves applying to both the feed and metering depths.

Melt conveying/Metering zone: The metering zone of a screw is where the plastic has finished melting and is ready to be pumped through the die. The supply material is consistent in temperature and pressure, and the depth is maintained.

Die: The following section is a key component that is attached to the end of the extruder. The die is designed and manufactured to fulfill a certain extruder size and the required form of the final product. Depending on the extrusion technique, a variety of die designs are available, and the die's specification is critical for precise production.[36]

2.1.7. Cooling

The hot extrudate material must be cooled after exiting the die in order to harden into the proper size. A cooling water bath, in which water is cycled or sprayed onto the object, is the most frequent method of cooling. The temperature of the water changes depending on the demands of the material being cooled; it might be room temperature or cooled. Depending on the polymer, the extrudate can also be treated with cooling-water or cooling-air or a mix of both systems can be employed for cooling.[37]

Except for the practical concept of extrusion, other mechanical parameters should be taken into consideration to obtain the desired printed material during the extrusion process.

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2.3. Melt Flow Rate Testing

Melt flow index (MFI) or rate (MFR) is an analysis method to determine the flow properties of a melted plastic by characterizing how many grams of a polymer flow through the die in 10 minutes(g/min). When describing a polymer, MFR is one of the most critical factors to specify. Generally, if MFR is a high value, it means the material has short chains and thereby a low molecular weight. High MFRs indicate that melting is easy, that less energy is required, and that processing is convenient. The resulting MFI value also indicates a substance's viscosity, with a higher MFR showing that it flows more quickly through an instrument. This research objective rHDPE and rPP were used in order to compare the values to the recycled one, and they were tested according to the ISO 1133 standard. Hamoud described that materials are preheated for 5 minutes at 190 ° C before a load of 2.16 kilograms is applied to the piston that presses the molten plastic through a die. MFI tests are also carried out with the same load as virgin HDPE at 190°C melting temperature. Each material test was repeated four times in a row, to get an average figure. The following data was collected by using a 30-second cutting interval on the plastometer.

Fig-15. Extrusion plastometer

Recycled HDPE weighs 0,18g in 30 seconds, In 1 min equals 0,36g, and in 10 min will equal 3,6g/10min.[36]

On the other hand for rPP, Iunolainen described, all the materials were preheated for 5 minutes, after preheating, the load of 2.16 kg material into the preheated extrusion plastometer with the degree of 230°C, then after setting the cut-off time period to 5 seconds, 5 grams of all tested materials were put into the barrel, followed by the insertion of a piston. The MFI (g/10min) was calculated using the following formula: MFI (230°C/2.16 kg) = 600m/t, where m is the average mass of the cut-offs (g) and t is the cut-off time interval (s), The following data was collected by using a 5-second cutting interval on the plastometer.

Recycled HDPE weighs 5g in 5-seconds, In 1 min equals 7,200g, and in 10 min will equal 72,000g/10min.[37]

2.4. Tensile testing

Tensile testing is used to acquire mechanical properties of rPP, rHDPE and virgin PP, HDPE, the dog-bone produced from injection moulding machine were tested to verify tensile strength, engineering stress and strain, elongation at yield, Young's modulus, and deformation to compare the mechanical data of recycled materials with those of virgin types (Fig-16). Following the ISO 1133 standard, virgin HDPE and recycled HDPE were evaluated at a load speed of 51mm/min. The number of dog bones analyzed was set to seven in order to be as precise as possible. The average value was obtained, and the test specimen dimensions were 120 x 12.8 x 3.1 mm.[36] Whereas, for virgin PP and recycled PP, the tests were carried out in line with ASTM Standard D638 at a speed of 2.5 mm/min. The test was done three times for each material to get average values. One test specimen is 33 x 5.45 x 1.6 mm in size.[37]

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Fig-16. Violet PP and rPP tensile test specimen

Fig-17. Tensile testing of the rPP test specimen

2.5. Diameter tolerance and Filament roundness

Due to production methods that always account for tolerances, the filament should maintain a consistent diameter over a whole spool. for instance, a 1.75mm filament diameter of rPP, allows for 0.3mm tolerances (Table-3). Extrusion should be done with care since incorrect extrusion results in inconsistent diameter. The filament size of rHDPE was measured with a venire caliper at intervals of 5 meters with a tolerance of +0,02. According to prior type filament manufacturing, a tolerance of +0,02 is permitted, and the available 3D printer also allows for a tolerance of 0,3 (1,75mm+0,3).[36] Table 3, shows the diameter value for the recycled PP filament.[37]

a (diameter) B (diameter) Average ø [mm] 1,729 1,925

Average Deviation ø [mm] 0,07 0,09 The % of average deviation from average 4,05 4,67

Max ø [mm] 1,88 2,05 Min ø [mm] 1,59 1,74

Max difference in ø [mm] 0,29 0,31 The % of the max difference from the average 16,77 16,1

max |a-b| 0,35 min |a-b| 0,05

Total length [mm] 40000

Table-3. Diameter values for the filament produced from provided rPP

The consistency of the filament during manufacturing is essential along the whole length of the spool. This is due to the filaments being compressed as they come into contact with wheels due to grasping and rotation winding.

Overall, the purpose of high quality filament in 3D printing is to provide consistent filament diameter (consistency) during the manufacturing process, as well as the ability to optimize this diameter at a bending angle to rap around the spool that will be utilized to suit the available 3D printer. The most commonly used standard filaments are 1.75mm and 3mm.[36] Table-4 compares the parameters of HDPE, PP, and their recycling types with two popular 3D printing materials.

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Tests

PLA

ABS

Tested HDPE (Mean Value)

Tested rHDPE

(Mean Value)

Sabic virgin PP

230°C/2.16 kg [g/10min]

CIRCO® recycled PP

(rPP) 230°C/2.16 kg

[g/10min] Melt index (g/10min) 2.4 – 4.3 22- 48 3,37 2,85 7,2 14,4

Tensile Strength (MPa) 50 - 55 30 - 52 25,45 25,59 31.65 25.18 Young’s modulus (MPa) 3500 1700 – 2800 463,35 428,38 677.1 594.32

Strain at Yield (%) 10 - 100 3 – 75 16,12 16,12 10.81 9.83 Melting temperature (0C) 120 - 190 200 - 230 190 190 230 230 Extruding Temperature

(oC) 160 – 220 210- 230 190 160 - 190 230 230

Table-4. Comparison table for 3D filaments

3. Additive manufacturing

The Economist magazine called Additive Manufacturing (AM) the third industrial revolution in 2012, it is also known as direct digital manufacturing. Due to new materials, entirely new methods such as 3D printing, easy-to-use robots, and new collaborative manufacturing services available online, it will allow products to be manufactured economically in much-limited quantity, more flexibly, and with a considerably lower labor input.[38]1 AM technology creates physical objects through digital information like piece by piece, line by line, surface by surface, or layer by layer. AM technology has advanced dramatically, and a wide range of materials are now available for processing which is an opportunity with the added value and benefit of recycling.[39]

There are other terms for this technology, the most used terms are; Layer Manufacturing, Rapid Prototyping, Digital Fabrication, Direct Manufacturing, and 3D Printing.[40]

3D printing, also known as additive manufacturing or direct digital manufacturing, is a process for joining materials and making a physical object from a three-dimensional digital model, typically by laying down many successive thin layers of material.[41]

Nowadays, 3D printing applications vary widely in human activity from research, engineering, medical industry, military, construction, architecture, fashion, education, the computer industry, and many others. Common benefits of additive manufacturing in many incentive industries for adopting this technology are the ability to facilitate sophisticated and complicated form to freedom of design like "If you can't build it, print it". 3D printers are autonomous or semi-autonomous construction technology that means it requires minimal human force and surveillance and is lighter and more mobile than conventional construction machinery which allows operating 24/7 by cutting construction times considerably.[42]2

3.1. 3D printing methods

3D printing has high scalability in terms of integrating it into the circular economy context, which supports sustainability and resource optimization by giving new enhanced qualities to manufacturers and reacting to flexible demand. 3D printing is an excellent technological trend to start defining sustainable operations, as well as cost and

1 Kafka, A. (2012). A third industrial revolution. 47.

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waste reduction. This technology is capable of developing economical solutions, providing high-quality services and products, and supporting a long-term and lucrative company plan.[43]3

3D printing operates in a completely different way than traditional printing. In the industry, 3D printing is known as additive manufacturing, which accurately describes how these machines work. To begin, additive refers to the fact that 3D printing technologies create solid three-dimensional objects by depositing objects or pouring thin layer by layer at an average rate of a few centimeters in height per hour; the layers solidify to form a solid three-dimensional object. Internal mechanics (such as ball bearings), woven and interwoven shapes or even hollow and curved forms can all be found in the finished product. Manufacturing, on the other hand, refers to the fact that 3D printers build these layers in a methodical, predictable, and repeatable procedure (Fig-18).

Fig-18. Schematic representation of the printing of an object by layers

A print bed, an extruder (through which the filament is slowly fed), a heat head, and a plastic filament are all required components of 3D printers, which are commonly employed in the cast-wire filing method. The many modifications of these four parts have a major impact on the machine's technical qualities. The printer might be quicker, more compact, or even more precise depending on the model. These four components are connected to a solid frame and are guided by a three-dimensional positioning system, and as well, 3D printers are available in a variety of sizes and shapes, and they're always connected to a variety of computer applications that are critical to the process since they enable us to prepare the 3D file for the thing we'll make and manage afterward. As a result, a 3D printer is a machine that can create a solid product from a 3D model.[35]

With the growth and progress of technology, numerous 3D printing technologies with various functions have been produced. ASTM Standard F2792* classified 3D printing methods into seven categories, including Binding jetting, Directed energy deposition, Material extrusion, Material jetting, Powder bed fusion, Sheet lamination, and Vat photopolymerization. There are no arguments over whether machine or technology is superior because each has its own set of applications. Nowadays, 3D printing technologies are utilized for more than just prototyping and are increasingly being employed to create a broad range of products, but in this case, we will focus on Material Extrusion method for utilizing plastic waste in a circular economy context.

3.2. Materials extrusion method

Material extrusion may be used to print multi-material and multi-color printing of polymers, food, or living cells. This method is frequently utilized, and the cost is quite affordable (Table-3). This technique may provide completely functional product parts. The earliest example of a material extrusion system is fused deposition modeling (FDM).[44] It operates by loading a spool of filament into the 3D printer and feeding it via a printer nozzle in the extrusion head. After heating the printer nozzle to the correct temperature, a motor pushes the filament through the heated nozzle,

* ASTM F2792-12a, Standard Terminology for Additive Manufacturing Technologies, (Withdrawn 2015), ASTM International, West Conshohocken, PA,

2012, www.astm.org

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causing it to melt. The printer then pushes the extrusion head along with the given coordinates, depositing the molten material on the build plate to cool and solidify. When a layer is finished, the printer moves on to the next layer. This procedure of printing cross-sections is continued until the object is entirely created, layer upon layer and as well, support structures may be required depending on the geometry of the product, for example, if a model includes steep overhanging portions.[45]

Characteristic Description Types of 3D Printing Technology Fused Deposition Modeling (FDM), sometimes called

Fused Filament Fabrication (FFF) Materials Thermoplastic filament (PLA, ABS, PET, PETG, TPU)

Dimensional Accuracy ±0.5% (lower limit ±0.5 mm) Common Applications Electrical housings; Form and fit testings; Jigs and

fixtures; Investment casting patterns Strengths Best surface finish; Full color and multi-material available

Weaknesses Brittle, not sustainable for mechanical parts; Higher cost than SLA/DLP for visual purposes

Table-5. Summary of Material extrusion method's technology (Source: www.all3dp.com)

There are many different types of 3D printing machines for this method such as traditional 3D printer with 3-axis movement which print layer-by-layer with support material But with the passage of time and the advancement of technology and taking advantage of the robotics industry and artificial intelligence, the freeform robot-arm 3D printer with 6-axis movements (Fig-19) model emerged which facilitates printing complicated and geometrical objects with no material support (Fig-20). This master's thesis will utilize the Material extrusion method of additive manufacturing for recycling discarded plastic.

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Fig-19. ABB 6-axis industrial robot arm

Fig-20. KUKA 6-axis industrial robot arm is printing complex geometries

➊ Fillament

➋ Extruder attachment (Nozzle)

➊

➋

➌

➍

➌ Air flow for cooling

➍ Print surface

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4. Plastic extrusion

Definition:

Plastic extrusion is a process that produces appropriate filament for dealing with polymers and composites, among other applications. Plastic extrusion has been in use since the early 1800s, when Thomas Hancock devised a technique to turn processing wastes into useable rubber. Alexander Parkes invented the first synthetic plastic in 1862, but no one utilized it as it was expensive to manufacture and of poor quality. After a German woman named Ashley Gershoff developed the first functional thermoplastic extraction procedure in 1935, proper plastic extrusion gained traction. This was quickly followed by the invention of twin-screw extruders in Italy by Roberto Colombo.[46]

Fig-21. Plastic Extrusions – Preferred Plastics

The current plastic extrusion business is focused on sustainability, generating a circular economy, boosting production speeds, reducing pollution, and improving precision. Plastic is extruded by manufacturers for a variety of applications ranging from daily food containers to industrial chemical processes.

5. Recycled plastic filament

The filament-making process is time-consuming and takes a significant amount of work. Finding plastic that can be readily cleaned and sorted is one difficulty. Because various polymers have different melting temperatures, they must be sorted into similar materials before being extruded. Combining various polymers might lower the filament's quality, uniformity, and color.

5.1. Preparing material for 3D printing

According to the conclusion in previous and reaching out what type of discarded plastic are appropriate in marine environments in Bio-Installation project, this part will proceed with physical and chemical's characteristics of polypropylene (PP) and Polyethylene (PP) and their limitations during extrusion and 3D printing process converting to filaments.

5.1.1. Plastics

In general, all plastics can be classified into two types of groups, Thermoplastics and Thermosets. Thermoplastics are solids at room temperature that may be heated to become soft and flexible, then placed in a mould or other shaping device and shaped after cooling. The ability to reheat a thermoplastic item and reshape it numerous times is a distinguishing feature of all thermoplastics (Fig-22). These special thermoplastics from thermosets, which cannot be remoulded once they have cooled. In addition, thermosets plastics undergo a crosslinking process in the mold that takes longer than thermoplastics to cool, which means that once formed, such crosslinked materials cannot be entirely remelted.[37]

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Fig-22. Molecular Structure of Thermoplastic and Thermoset Polymers [47]

Thermoplastics are also classified into two groups based on their shape (how the molecules are organized). Two different forms of the structure appear depending on the degree of intermolecular interactions that occur between the polymer chains.

• Amorphous structure: The elastic characteristics of thermoplastic materials are due to this sort of structure, in which the polymer chains are packed disorderly or randomly.

• Crystal structure: The polymer chains form an ordered compacted structure that is directly responsible for the mechanical characteristics of thermoplastics materials, such as stress or load resistance and temperature.[36]

Even though polymers cannot be completely crystalline, they do contain some amorphous areas. Crystalline or, to put it another way, semi-crystalline materials have a high concentration of crystalline zones (maximum 80 percent degree of crystallinity).

Fig-23. Amorphous and semi-crystalline regions in a polymer structure

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Semi-crystalline/Crystalline polymers Amorphous polymers

The polyethylene family (LDPE, HDPE), polypropylene (PP), nylon, and polyester

thermoplastic PLA

Acrylonitrile butadiene styrene (ABS), polycarbonate (PC), acrylic (PMMA), and polystyrene (PS)

Generally opaque Usually transparent Higher chemical resistance, and resistance to

stress-cracking and fatigue because of the uniform structure

Stress-cracking vulnerability and low fatigue resistance because of the random structure of

molecules Harder to bond Easier to bond

Higher shrinkage upon cooling, harder to process because the molecules in the polymer are densely

packed to a highly aligned structure when the substance solidifies

Lower shrinkage upon cooling, easier to process Because of the random arrangement of molecules,

minimal volume change occurs.

Table-6. Common characteristics of semi-crystalline and amorphous plastics

5.1.2. Polypropylene (PP)

Polypropylene (PP) is a thermoplastic polymer made by polymerizing propylene molecules, which behave as monomer units, into long polymer chains(Fig-23). The arrangement of the methyl groups, which are connected to every second carbon atom in the chain, determines the structure. When all of the methyl groups are on the same side of the macromolecular backbone, as seen in (Fig-25), the result is called isotactic PP.

Fig-24. Propylene monomer

Fig-25. Isotactic polypropylene

There are other types of formation PP chain structure, methyl groups are attached to the backbone chain in an alternating manner, while in another structure, each chain has methyl groups located randomly along the chain, called “syndiotactic” and “atactic”, respectively. The most commercially important form of PP is isotactic since only highly

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crystallized PP has the properties required for practical plastic material and it is more rigid and resistant than both syndiotactic and atactic.

The typical physical and mechanical properties of unmodified PP and recycled PP* 4( CIRCO® recycled PP refined by Fortum) for this study have been provided and experimented by Elina Iunolainen.[37]5Data related to both polymers is shown in table-7 and table-8.

Material Property PP Density 0.90-0.91 g/cm3

Glass Transition Temperature (Tg) -20 – 20 °C Melting Point (Tm) 160-165 °C

Processing Tem-perature 200-230 °C Heat deflection temperature (HDT) at 0.46 MPa. 100 °C

Tensile Strength at yield 26 MPa Young’s Modulus 1.3-1.5 GPa Flexural Modulus 1.5-2 GPa

Impact Strength (Notched Izod im-pact at 23°C) 150 J/m

Table-7. Typical material properties of isotactic PP

Property Value Density at 23°C 905 kg/m3

MFI 230°C/2.16 kg 11 g/10min Tensile strength at break MD 21.4 MPa

Elongation at yield MD 7.2 % Tensile strength at yield MD 26 MPa

Tensile Modulus 1.3 GPa Impact strength 60

Flexural Modulus 1.3 GPa

Table-8. Some properties of the provided rPP (Fortum CIRCO® Polypropen Material Datasheet

5.1.3. Polyethylene (PE)

Polyethylene is a thermoplastic material that comes in a variety of shapes and grades for a variety of uses. It is the most common and significant polymer, contributing to the majority of the plastic family. They are recognized by the way the chains are created and are produced from the monomer ethylene (Fig-26).

* Fortum is a clean-energy company that delivers electricity, heating and cooling as well as has its own Recycling and Waste Solutions unit to

enhance resource efficiency. Fortum has a Circular Economy Village in Riihimäki, Finland. Materials taken from municipal waste are heading to recycling through the Plastic Refinery and the Bio Refinery. The Plastic Refinery deals with plastics collected separately from industry and the retail sector and redirects them back into the cycle to replace virgin raw ma-terials.

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Fig-26. Repeating unit chains of polyethylene

HDPE outperforms other polyethylenes due to its superior mechanical characteristics, such as high compressive tensile strength, stiffness, and melting temperature, as well as higher crystallinity. The degree to which these materials are dense is defined by crystallinity, which is determined by the molecular weight and polymer branching structure. HDPE comes in a variety of densities, hyper-branched crystallinities, and classifications based on its molecular weight and chain structure, as seen in the following table;

PE

Density (g/cm³)

Degree of Crystallinity (%)

Number of branches (per 1000 carbon atoms)

LDPE 0.910 – 0.925 20– 30 (methyl); 3– 5 (n-butyl) 40 -50 LLDPE 0.910– 0.925 - - MDPE 0.926– 0.940 4– 6 - HDPE 0.942– 0.965 4 (Phillips); 5– 7 (Ziegler) 70 – 90

Table-9. Characteristics of different PE grades

In general, due to the outstanding mechanical characteristics of HDPE described in previous paragraphs, it is considered to proceed with this project using HDPE rather than other PE's family. The most common physical and mechanical properties of HDPE can be seen in bellow; [36]

Property Unit Value Density 0.942– 0.965 (g/cm³)

Melting point 120 - 135°C Tensile Strength 20 - 40MPa Strain at break 100 – 1000 (150%)

Tensile modulus 413- 1241MPa Elastic modulus 0.2 – 1.2 (GPa)

Glass transition temperature 110°C Coefficient of Thermal expansion 100 - 120×10-6 m/m oC

Thermal conductivity 0.38- 0.51W/mK Notched Impact strength (charpy) 2 -12 kJ/m²

Resistance Above 100°C Crystallinity Greater than >90% (high crystalline) Flexibility More rigid

Table-10. Common engineering properties of HDPE

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5.2. Extrusion equipment

Fig-27. KFM extruder

Fig-28. Temperature zones

Fig-29. Cooling water bath

Fig-30. Cold-air gun

Fig-31. Puller

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5.3. Filament extrusion

Based on Iunolainen's research, several test runs were conducted in order to optimize the extrusion process and create the highest quality rPP filament possible. Ideally, the filament should be a continuously round-shaped thread with a constant diameter of 1.75 mm, no abrupt variations, and a smooth surface free of contaminants over its entire length. Filament produced from the Circo rPP has been tested in three experiments to see if it is suitable for direct use in a 3D printer. The surface of the rPP produced by these experiments was considered the best of the three (Table-11), but still far from optimal in terms of quality for direct use in a 3D printer because the surface was not completely smooth, and there were still significant diameter variations.[37] Hamod in his experiment described that during the extrusion test, two different types of dies were used to make the filament. The filament with a die diameter of 6mm was too large to optimize to the required filament size, and it shrank too quickly and twisted as soon as it came into contact with water. The 2mm filament die was first tested with HDPE at the same cooling method and pulling voltage to obtain some rough data that could be optimized, and then more than seven trials with rHDPE material were conducted to obtain reasonable data that could be used as a primary source of data. The extrusion temperature stayed constant throughout when rHDPE was utilized, although other parameters were changed (Table-12).[36]

Test Experiment Extrusion T (zones 5 to 1 re-spectively) 225-225-215-215-210 [˚C]

Extrusion speed 25 rpm Cooling method Water bath

Water T in the water bath 50 ˚C Cleaning material Violet Sabic PP

Outcome

• Less rough surface with almost no

contaminated areas • Big diameter variations • Not perfectly round-shaped, rather elliptical

Table-11. The extrusion parameters and results for recycled PP

Test Experiment Extrusion temperatures zones (0C) 175

Extrusion speed (rpm) 15 Cooling method Room temperature

Pulling device voltage (V) 8,4 Filament size (mm) 1,75+0,02

Outcome

• Filament consistency and diameter circularity

• Almost round shape • Very little diameter variation • Suitable filament for 3D printing with

noticing to availability of form-core board as a serving a printing bed

Table-12. The extrusion parameters and results for recycled HDPE

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Fig-32. Produced filament from provided rPP

Fig-33. Produced recycled HDPE filament

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Result

As the study showed in Iunolainen's research, during printing, PP warps significantly and has poor layer adhesion. CIRCO® rPP offers superior flow characteristics than virgin PP, and there is no noticeable change in mechanical properties. It has far higher MFI values than both ABS and PLA commercial filaments. The best potential results in terms of filament quality may be reached by employing a water bath as a cooling technique, with the cooling water temperature being significantly higher than room temperature and the extrusion temperatures being reasonably high. The findings of the literature review revealed that the crystalline structure of PP is the primary cause for its unpopularity as a 3D printing material.[37]

Another research work concluded by Atsani and Mastrisiswadi, studied for the first time the improvement of extrusion parameters in the manufacturing of recycled plastic filaments Polypropylene (PP0. The Taguchi and ANOVA (The Taguchi analysis is used to detect the best level for each parameter, while the ANOVA method is used to evaluate the relationship between the parameters and the response variable) techniques were used to analyze the extrusion process. According to the findings of this study, a spooler speed of 4 rpm, an extrusion speed of 40 rpm, and an extrusion temperature of 200ºC in the parameter setting create an average filament diameter of 1.6 mm. However, filaments produced from Recycled Plastic (Polypropylene) had a rough and readily bendable surface, necessitating further investigations.[48]

Hamod's research focuses on the HDPE recycling process, as well as 3D filament specifications and production factors. ABS, PLA, and HDPE data were compared to determine if there was a possible link between the materials, and it was discovered that recycled HDPE data matches PLA data in terms of melt flow, yield strain melt temperature, and extruding temperature. The only difference in tensile strength and young's modulus is the test done, and it is not comparable to ABS or PLA. Since the data link with PLA, it can be determined that recycled HDPE is acceptable for 3D filament.[36]

Additionally, according to Table 13 (Reuse of PP & HDPE waste from different origins to produce 3D printing filaments), utilizing additives during the extrusion process to improve the mechanical characteristics of recycled materials, showed that filaments based on hemp, harakeke fibers, or recovered gypsum (0–50 wt.) were individually added to the process of generating new types of materials to improve the value of recycled polypropylene (PP). The filaments constructed of harakeke fibers produced the greatest results (30 wt.; tensile strength 39 MPa, Young modulus 2.8 GPa). Those materials, on the other hand, have the potential to lose characteristics during printing procedures. Another attempt to improve the quality of recycled polymers was based on the incorporation of nanocrystalline powders Fe, Si, Cr, and Al into the extrusion of PP and HDPE filaments. When a 1% mixture of powder (Fe-Si-Cr or Fe-Si-Al) was added, the yield strength (37%) and Young modulus (17%) were found to be higher than the basic materials values. Metals also decrease the chance of cracks forming. The use of an additive in the form of SiC/Al2O3 resulted in a substantial increase in the mechanical strength of recycled HDPE. HDPE waste is combined with reinforcement (SiC/Al2O3) and a binding agent, such as paraffin wax. A screw extruder is used to feed the prepared mixture. The additive has a minor effect on the material's thermal properties but has a substantial impact on its mechanical strength.

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Materials Origin Additives References

PP

Granules of pre-consumer recycled PP

(Astron, Auckland, New Zealand)

Hemp fiber Harakeke fiber

MAPP (maleated polypropylene)

Recycled gypsum

[49]

PP McDonnough plastics - [50]

PP Postconsumer hard

plastics Iron [51]

HDPE HD50MA180 (Reliance Polymers)

- [52]

HDPE Unknown source - [53]

HDPE

Detergent containers Shampoo bottles

Household bottles Milk bottles

- [54]

HDPE Plastic bags (DA.IA Technology, Taiwan)

Silicon Chromium Aluminum

(nano-crystalline powders)

[51]

HDPE Unknown source (nano-crystalline powders) 52]

Table-13. Reuse of PP & HDPE waste from different origins to produce 3D printing filaments

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CHAPTER THREE

Introduction

This chapter proceeds with the main project of the dissertation that will introduce the BioInstallation project and present a broader view of users, stakeholders relationship, and business model framework. Finally will verify the case study and discuss it with the reflection.

Chapter overview:

• Installation • BioInstallation • Stakeholders partnership • Bussines model canvas • Case study analysis

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Introduction

Literature reviews

1. Installation:

Installation Art is a broader term that refers to a variety of artistic practices, including the installation or configuration of objects in space, where the totality of the objects and space contains the artworks. Installation Art is a process of designing and displaying artwork rather than a movement or style. In reality, it can include both classic and non-traditional mediums like painting, sculpture, readymade found objects, drawings, and texts. However, the "Installations" space or contents might occasionally determine its sizes. It can range from miniature to giant.[55]

Installation art refers to a type of art that consists of site-specific, three-dimensional works that aim to affect a viewer's impression of a space. The word is usually used to interior places, whereas external interventions are commonly referred to as Land art; nevertheless, the lines between these categories blur. The interactive installation is a sub-category of installation art that the audience often interacts with the work of art, or the artwork responds to human behavior.[56]

1.1 Installation art out of plastic waste & Precedents

Artists from all across the world have worked with a variety of materials to express themselves creatively through sculpture in several ways. Objects recovered from waste or dumpsites, such as cans, bottles, bottle tops and caps, bits of fabric, rope, old newspapers, recharge cards, nylons/wrappers, tree barks, to name a few, have been studied by artists in sculpture in comparison to the conventional ones like stone, wood, metal, etc.[57]

Pamela Longobardi, one of the most important conceptual artists of the new generation in the United States and one of the first in the world to recognize the importance of the conflicting relationship between nature and global consumerism culture, began to ‘build' her ecological ideology for art in 2006. She began by focusing on the immediate removal of plastic trash from the shores and beaches of America, particularly Hawaii, but also from other regions of the world, such as the Mediterranean Sea and the Gulf of Mexico, intending to clean them completely. Her next step was to convert these previously ecologically harmful materials into impressive, huge works of art. in following her works and other artists that involved in the transformation of plastic waste into art in public spaces, are also very political in that they draw attention to the extremely severe problem of environmental pollution in a dramatically

Fig-34. Neorizon, Maurice Benayoun, urban interactive art installation (eArts Festival Shanghai 2008)

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visible fashion, highlighting the global governments' long-standing disregard to the issue, can be seen regarding the use of waste plastic as a Source of Inspiration and a Form of communication.[58]

Fig-35. Pamela Longobardi: Bounty, Pilfered, 2014. Fishing nets, floats and plastic parts on metal armature. © Chris Arend, Anchorage Museum

Fig-36. Pamela Longobardi: Anchor (our albatross), 2017. Urban and ocean plastic waste from Hawaii, Atlanta and Greece. © Hathaway Contemporary Gallery.

Fig-37. Pascale Marthine Tayou, Plastic Bags installation, 2013. © Giorgio Benni / Queensland Art Gallery.

Fig-38. Pascale Marthine Tayou, Plastic Tree, 2015. © Andrea Rossetti / Galleria Continua.

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2. BioInstalation

The word Bio is derived from a Greek word that means life or living thing. Living things (bacteria, fungi, plants, and animals) may be discriminated from nonliving things (a piece of wood, plastic, metal, stone, etc) by their properties of life. All living things have several basic characteristics in common: Growing, respiration, movement, feeding, secretion, excretion (waste), reproduction, and sensation are all functions of living creatures. Living things are sensitive, which means they may react to stimuli. Living things have the ability to develop, grow, and reproduce. The hereditary molecule DNA is used by all known living organisms.[59] Thus, BioInstallation can contain at least one or many living-thing properties, implying that it includes both living and nonliving things. In other words, living organisms such as bacteria, fungus, and plants will grow, develop, generate, and feed in the heart of a nonliving object such as a piece of plastic.

BioInstalation is the project that has investigated to proposing the possibility of utilizing appropriate and discarded plastics into an object of aesthetic value in urban environments. With the view of making recycling discarded plastics like PP or PE(HDPE), which have been conducted in previous chapters, into filaments and convert them to a form that makes a bed for fostering plants, herbs, and flowers and feeding source for local terrestrial and aquatic creatures through 3D printing to improve ecosystem service and help to increase biodiversity. Therefore, being part of nature and preventing plastic waste from becoming a threat to both people and the environment.

The objective of the BioInstallation project is to bring a socio-ecosystem approach to environmental urban management that provides a significant and valuable path to greater integration of biodiversity into urban planning, particularly urban environments like ponds, lakes, harbors, and sustainability while taking into account cultural attitudes toward urban ecosystem services through community engagement, increased social collaboration, associative ability, social interaction, and crime decrement by providing lively spaces in order to protect human well-being and natural system, since societies are intimately connected to ecosystems, relying on and shaping the ecological services they provide.

Fig-39. Daydreamers Design Co. Rising Moon project, exterior view. Hong Kong, 2013. © Charles Chun Wai Lai.

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2.1. Ecosystem services

Ecosystem services are the advantages that humans obtain from ecosystems that are co-produced by the ecosystem and society. Ecosystem services are the circumstances and processes by which natural ecosystems and the organisms that comprise them support and satisfy human life. They preserve biodiversity and the production of ecosystem commodities like fish, forage wood, biomass fuels, natural fiber, and a wide range of pharmaceutical, manufactured products, and their precursors. Ecosystem services have been classified in a variety of ways, including:[60]

Provisioning services; the goods or products

obtained from ecosystems

• Food • Freshwater • Wood fuel • Fiber • Biochemicals • Genetic resources • Ornamental resources

Regulating services; Benefits obtained from the

regulation of ecosystem services

• Air quality maintenance • Climate regulation • Human disease regulation • Water regulation • Water purification & waste

treatment • Pollination • Storm protection • Erosion control • Biological control

Cultural services; Nonmaterial benefits obtained

from ecosystems

• Cultural diversity • Spiritual & religious values • Knowledge system • Educational values • Inspiration • Aesthetic values • Social relations • Sense of place • Cultural heritage values • Recreation & ecotourism values

Supporting services; Services necessary for all other

ecosystem services

• Soil formation • Nutrient cycling • Primary production

Table-14. Ecosystem services

2.2. Role of biodiversity in ecosystem services

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Biodiversity is linked to ecosystem services via a number of processes that operate at multiple scales. Biodiversity regulates the status, rates, and, in many cases, stability of ecosystem processes that are essential to the provision of most ecosystem services.[61] Changes in biodiversity throughout numerous species across most ecosystems are being caused by habitat alteration, invasion, and a variety of other reasons. The degree of functional redundancy discovered within an ecosystem is one of the most critical aspects recognized. This describes the substitutability of species within functional groups in an ecosystem, such that the impact of the loss of one or more species is balanced by the loss of others. For instance, there are numerous species that fix nitrogen in many environments, for example (known as a functional group of species). There is functional redundancy in that ecosystem if the loss of one of them is compensated for by the development of others, and there is no overall loss in nitrogen fixation. Changes in biodiversity in varied systems may result in relatively minor changes in ecosystem functioning, ensuring that no species with distinct functions are eliminated. Some species, on the other hand, offer unique or distinctive contributions to ecosystem functioning, and hence their loss is of more concern. As more species are lost and redundancy is decreased, the risk of severe functional losses grows. For instance, the enormous variety of South African fynbos ecosystems maintains stable rates of production, since many plant species can compensate for losses by growing when others can not. Greater redundancy ensures that an ecosystem can continue to deliver better and more predictable service levels.[60]

Formerly, I discussed which type of discarded plastics is appropriate in a marine environment and then the process of converting them to recycling filaments through additive manufacturing technology. The following will narrow down other aspects of the project like value deconstruction, users, stakeholders relationship, and business model canvas.

2.3. Value deconstruction of BioInstallation

Prices and financing: the cost of the BioInstallation project has been calculated approximately, although the most of cost will encompass three-pillar infrastructures which include: preparing a certain trash bin for collecting using discarded plastics by municipality resources next to other trash bin spots around the city, it should be noted, the only type of plastic materials .e.g PP, PE can be utilized for this project, then the main cost would be referred to additive manufacturing process by NGOs and charities of nature conservation resources like preparing laboratory, workshop with considering 3D printer and filament extruder machines.

Aesthetic image and brand: Obviously by processing the project more ideas would be aspired to deal with aesthetic image and brand for the project to become more tangible and comprehensive for the audience, however, the following boards already have been designed by the designer, and all explanations indicated in them.

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Fig-40. Brand identity-Associations. ( the first things that come to our mind, if we use elements like animals, Materials, colors, etc that make communication to our identity. Benchmarking; is about figuring out what sort of relationship we can establish with some interesting attribute of particular brands)

Fig-41. Look for inspiration- Mood board (it contains a variety of images, text, and other elements that can be connected to our brand)

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Fig-42. Design logo

Novelty: it is clear that plastic landfills and plastic debris in the ocean are one the most significant problematic issues which human beings have been faced for a long time, and as well, water and CO2 footprint are impacts of plastic recycling plants and facilities, on the other hand, urban ecology and terrestrial and aquatic species are in endangered by human activity and urbanism, so the idea of the BioInstallation will show the novelty of the project, not only reduce plastic waste but also reusing, redesigning and remanufacturing them for another aspect to help human beings to live in good condition. Practically, the main idea of this project is "from grave to cradle"

Customer experience empathy: BioInstallation has a sense of empathy with part of society who are citizens and single-use plastic producers who are reckless and contribute to plastic pollution, and these are citizens (final users) who are connected with this project directly.

In the cultural and contextual aspect of the project, there might be an objection, because many individuals and experts believe that the using way of plastic by people causes polluting environment, not plastic, in another, who pollutes is not plastic but the people that use it. Hence, on one hand, the idea of the BioInstallation proposition is the solution to the existing problematic issue of plastic in landfills or ocean debris, on the other hand, training and preparing the social behavior for collecting using material like PP and PE that have been recognized as the proper plastics for this project (Fig-44). This important matter as a part of the provided solution could be handled through participating municipalities with citizens/people via considering some sort of designed trash bins next to locations of garbage cans across the urban area which are labeled with plastic recycling symbols (Fig-43). Thus, this door-by-door cumulation would be a potential effort to drive people to be more responsible about their dwelling and to facilitate recycling waste management. Therefore, The socio-ecosystem approach means considering and stimulating cultural attitudes in society at the same helping urban ecology values, BioInstallation will provoke people to contribute to building artificial wetlands in environment urban by discarded plastics that have been produced by themselves.

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Fig-43. Placement BioInstallation's trash bin next to garbage spot

Fig-44. Defined trash bin for collecting materials of BioInstallation

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Specialization and line: The most significant and highlighted attribute in this project would be the closing loop (from the grave into cradle), recycling discarded plastics through a circular economy, reusing recycling filaments via additive manufacturing, and finally, redesigning the new concept of environment-friendly products and remanufacturing artificial wetlands with freeform fabricator like 3D printer.

Capacity, logistics, and distribution: The normal size would be 2*2 m that has been designed in design part, no matter what size and what form it has, the important is which location with what functionality it faces, for instance, it could be part of an outdoor pool in order to purify water naturally. but it relies on its location and citizen, municipality, and NGO's participation. Logistics and distribution are planned to consider two parts; 1- those villas are located to close coastal cities and open areas. 2- Any water resource e.g. urban lakes/ponds/harbors are needed for this product which will be lunch by the municipality in different logistics

3. Customers & Stakeholders

The customers in the BioInstallation project consisted of three parts. The main target customer would be part of the private sector, to use this product/service as a natural water refinery and water waste treatment ( who live in a vacancy of storm or rainstorm regions or suffering from industrial wastewater by living in an industrial zone) and providing a bed to foster flowers and growing plants and farming as well. The second part would be the governmental sector (municipality) who will be influenced by the project goal directly and the third part in this project would be NGOs and charities of nature conservation that will receive the main goal and the impacts of BioInstallation indirectly. Figure-45 illustrates all stakeholders and their relationships with the BioInstallation project.

3.1. User

BioInstallation will be aimed towards the whole society in every sector, but first and most communities should be targeted are citizens and parts of this community are reckless and irresponsible about this global concern and pollute their habitat environment and as well as, plastic industries as single-use plastics producers that have a significant role in the context of distributing plastic waste in landfills and ocean debris and other stakeholders by their inefficient waste management.

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Fig-45. Stakeholder relationship

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4. Business model plan

Regarding selling the BioInstallation the main buyer and investor would be the government sector primarily (municipality, environment preservation organs) and promising NGOs who convince the public sector for investing, since abandoned waste plastics and contaminated water by them is an environmental problem and following that urban ecology and climate change issues is appearing. Firstly, the idea in the public sector is that to increase their income through social engagement and interaction in the vacancy of BioInstallation zone that means by transforming a rejected and abandoned place into a super active and vibrant place, plenty of businesses like Bar, café, Restaurant will invest there, hence municipality can income money by selling construction license or renting a part of the terrain. Secondly, the idea in the private sector is that to reduce their water refinery system price, for instance, to design embedded installation as a part of outdoor pools, generating a combination of homy and natural style space in order to purify water naturally.

Fig-46. Business canvas model of the BioInstallation

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4.1. Digital presence

Since BioInstallation is a multifunctional project with two distinct audience pillars (government and citizens), it will connect with them via a multiple website+platform. It primarily requires two channels: one for connecting with consumers and the other for producing content for them. For the first (communication), it is best to utilize a single website+application, and for the second (content production), BioInstallation has the ability to leverage accessible through digital magazines like E-The Environmental Magazine, Mother Earth News, The Ecologist, or Down to Earth, and as well as, digital marketing tools in combination with social media platforms such as Instagram or Telegram. Furthermore, creating inspirational (for citizens and designer team), emotional (for citizens), motivational (for citizens) and promotional (for citizens, stakeholders) could be taken into consideration as content strategies associated with the BioInstallation project. Social networks, such as Instagram, which is considered a content production route for this project, may principally promote BioInstallation. Customers, consumers, and the BioInstallation team might use Whatsapp and Telegram as contribution and interaction platforms.

4.2. BioInstallation as a wetland

Wetlands provide three important services: flood control, water purification, and biodiversity support. Many wetlands in the upper section of a watershed retain water that travels overland toward rivers and streams; they can gradually release this water into the main channel, lowering and delaying flood peaks. Wetlands filter out various nutrients, other pollutants, and sediment; they support microbial cells that denitrify waste; plants take up and store nutrients, and wetlands improve sedimentation by slowing and diverting water flow - the accumulating sediments effectively bury contaminants. While many wetlands may economically purify water, their efficiency is dependent on a variety of parameters, including the rate of intake, the quantity of sediment and organics in the wastewater, the residence period of the wastewater in the wetland, and total surface area.

Wetlands provide a variety of services, including flood mitigation and water purification, soil formation, protection against saltwater intrusion, and biodiversity support. Wetlands are vital to the survival of a broad range of species. Plant species that provide flood protection and water purification can also contribute to biodiversity by offering a variety of food and shelter. A riparian wetland may offer muskrats with food plants and underwater tunnels, ducks with seeds and nesting materials, and fish and insects with food and shelter. Wetland-related goods include peat, wood, and mulch. Waste purification, carbon storage, and crop protection are examples of regulatory services. Many cultural services are provided by wetlands, such as bird viewing, boating, and hunting. According to the United Nations, 50% of wetlands have been lost worldwide since 1900 in favor of other land use, and their value is estimated to be in the tens of billions of dollars. Wetlands are protected by the Ramsar Convention on Wetlands* and are regulated by local legislation in many nations.[62] 6

• The Ramsar Convention, is a global inter- governmental treaty that provides the frame- work for national action and international cooperation for the

conservation and wise use of wetlands and their resources. and is so named for the city in Iran where the treaty was signed in 1971. https://www.ramsar.org/sites/default/files/fs_6_ramsar_convention.pdf

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5. Case studies analysis

Case study 1

Project Name: Rotterdam's floating park

• Lead designer: Recycled Island Foundation • Place: Tillemakade, Rotterdam, Netherland, 2018 • Client: The Rotterdam Municipality

The floating park is a series of a collection of hexagonal blocks constructed completely of recycled plastic waste. The Recycled Island Foundation aimed to build blocks in recycled plastic as a great step toward a litter-free river. To collect debris, the foundation created three passive litter traps, which were tested, monitored, and refined during a 1.5-year trial period. The litter traps may collect plastics by utilizing the river's existing stream and keep them trapped even when the direction of the stream changes.

Fig-47. Floating park

Fig-48. Outlook of floating park Fig-49. Litter trapper

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Fig-50. Litter trapper

The park is important to the river's ecosystem since it provides a habitat for micro and macro fauna such as snails, flatworms, beetles, and fish.[63]

Case study 2

Project Name: Urban Aquatic Health: Integrating New Technologies and Resiliency into Floating Wetlands (2018 ASLA Professional Award)

• Lead designer: Ayers Saint Gross • Place: Baltimore, Maryland State, USA, 2018 • Client: National Aquarium

The National Aquarium is located on a typical post-industrial urban coastline in Baltimore, Maryland. Their unique position as global players and habitat specialists places them ideally to be change-makers for urban water quality. The Aquarium collaborated with designers, engineers, and researchers to study new technologies to create a more sustainable and high-performing floating wetland, with the ultimate objective of transforming its site into a living research facility. Using material are Layered unwoven polyethelene terepthalate (PET media) is used to construct topographic microhabitats. In prototype research three pillars criteria have been evaluated including; habitat creation; Wetlands are built at a certain level in the water column to accommodate a range of habitat conditions both above and below the water's surface. Fig-51. Prototype adaptability

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Then, wetland resiliency; The prototype needs constructed flotation devices to maintain proper levels and stability when subjected to environmental or people pressures, and they are limited to having very little reserve buoyancy that has been fulfilled through reserve, static and dynamic buoyancy pontoon system. Finally, water quality that the prototype aeration system allows for the testing of various materials and aeration technologies to increase dissolved oxygen levels within the water body and ensure the survival of fish, oysters, and other aquatic organisms during low-oxygen events such as algae blooms and turn-over periods.[64]

Fig-52. Long-term campus vision & Observed species on prototype

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Case study 3

Project Name: Natural swimming pool

• Lead designer: Herzog & de Meuron • Place: Naturbad reiehen, Switzerland, 2014 • Client: Residens of Riehen

The natural swimming pool in Naturbad Riehen will be cleaned without the use of chlorine or other chemicals, instead, it is processing and treating the water through surrounding landscaping and aquatic systems. The design team was able to develop a better version of the swimming pool due to the new technology and a deeper grasp of natural water filtering processes. To treat and purify the water, the pool employs a series of filters. Particles, grease, and hair are first squeezed out. The water then flows across the street to the regeneration area, where plants like water lilies and irises filter and absorb bacteria and other chemicals in collaboration with aquatic sediment.

Fig-53. Outlook of Naturbad

The method creates clean water, which is then pumped back into the pools. On any given day, the pool and its regeneration mechanism will allow 2,000 people to enjoy the natural swimming pool.

Fig-53. Water filtering process & Natural swimming pool

The Naturbad Riehen will have a lap pool, a diving area, a leisure swimming area, and a children's pool. Families will be able to play and picnic in the surrounding park-like environment. On-site restrooms and change rooms are also available.[66]

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CHAPTER FOUR

Introduction

The following chapter will focus on processing the BioInstallation design. After determining the printability of the discarded plastic into filament, a design prototype is creating. This section of the dissertation will discuss the design route, concept, and inspiration that formed the prototype and relevant sketches and reaching the details of prototype design and digital design outcome. Finally, the thesis will be closed with the conclusion and possible suggestions.

Chapter overview

• Design route • Prototype design process • Digital design outcome

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1. Design route

The BioInstallation idea came to my mind when taking inspiration from floating discarded plastics on the ocean surface and the effects of wetlands on local ecosystems. I was thinking instead of leaving worthless, unusable, and intact plastics like floating objects that make to create ocean debris, whereas they are nonbiodegradable and nondecomposable substances, leveraging their properties like, low density, lightness, and high durability, at the same time, giving them a potential function that could drive them to be at the service of nature like wetlands not against, on the other hand, we know that all these implications are the outcome by behavior-consuming of human beings. In the face of these problems, a couple of challenges come up including; How to use waste plastics correctly? How to construct an artificial wetland with discarded plastic? How to change the way of consumer behavior? How to design a process that could be socially acceptable and running by actors of this socio-ecological consequence? How to stop polluting the environment?

In the solution part (Fig-54), I was faced with more challengeable questions like, Shall I use only intact and clean discarded plastic bottles or other plastics that can be utilized? Is there any proper technology is available? What type of plastic is appropriate for the marine environment? The structure could be like what? How to motivate people to participate in this project? How to use discarded plastic as the material? Then by progressing and searching more, reaching what if part, like what if use specific plastic-type for the marine environment?! What if use additive manufacturing for converting recycling material by discarded plastic, What if define a trash bin for collecting using material and encouraging citizens to participle in this project?

After proposing solutions and answering my research questions, I reached out to the prototype step where I proposed to design a constructed wetland by discarded plastic through additive manufacturing in order to improve ecosystem services, increase biodiversity and enhance urban ecology. In meantime, the business model plan has been defined, and in further steps, when the prototype is designed it should be validated by the main executor and one of the stakeholders for instance municipality, and then enter to agile marketing step the primary prototype would be implemented in one of recognized and defined urban water parks to be tested and got feedback from a member of validation and visitors and thus, the final product could be delivered in any places.

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Fig-54. Solution mindmap

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2. Prototype design process

The first step in forming a prototype is to design based on a good concept. Every design prototype needs an innovative idea. Due to my interest in nature and also the significant role of wetlands in the ecosystem and the environment, I was looking to get inspiration from nature. After studying relevant cases, I decided to select and proceed with a leaf, from a species of flowering plant which is named, Victoria Amazonica. The Victoria Amazonica is the biggest member of the Nymphaeaceae family of water lilies and Guyana's national flower. It is native to Guyana and tropical South America. Victoria Amazonica has incredibly large leaves that may grow to be 3 m (10 ft) in diameter and float on the water's surface on a submerged stalk 7–8 m (23–26 ft) in length. It is the world's biggest waterlily.[66]

Fig-55. Victoria Amazonica leaves

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The underside leaf structure of Victoria Amazonica has an extremely complex architectural pattern. The complicated vein network on the underside of the leaf provides the essential support for the leaf's large flat surface to remain stable.

Fig-56. The underside of Victoria Amazonica leaf

This structural pattern of vein below the leaves provided the inspiration for my prototype design. The following figures will illustrate my relevant sketches from how this idea formed in my mind to another aspect of design and prototype's structure.

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Fig-57. Initial sketches of prototype design

If we look at this pattern from the upside, a couple of intersecting lines are visible that can be inspired for closing polylines in 2D modeling that form integrated and closed polylines. These disordered and closed polylines can generate through a set of points in the center of each closed polyline that is commonly named the Voronoi pattern in parametric design.

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2.1. The digital system

The creation of a parametric system is the first step in the graphical interface for producing a design output. In my case, I used the Grasshopper plugin in the Rhinoceros interface in order to design a cell. A rectangular surface is required for the cell to be created. The grasshopper code will allow you to determine the surface area and as a result, form and choose the cell size.

• Step one: A surface area for creating cells is established

• Step two: The surface is divided into points to

control the number of cells

• Step three: in this stage that is illustrated in Fig-52 the Voronoi pattern is created and multiple points are defined to create pulling boundaries with different size and scale cells.

• Step four: The surface is divided into desired cells.

• Step five: The cell is preparing in this stage after manipulating the size, scale, and shape. This code can be attached to another code to define final cells based on the required function of the prototype. Then cells are ready to print.

Fig-58. The digital process

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Fig-59. The grasshopper code

The Bio Installation prototype seeks to evaluate three main criteria, including aeration, buoyancy, and habitat creation in design. My goal is to design an object that meets these criteria and an integrated system that operates all three criteria simultaneously. The initial concept is illustrated below sketches;

Fig-60. Initial sketches of prototype design

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Habitat creation; The prototype design consists of integrated cells with different elevations and holes inside the cells to stay at a set level in the water column to support a wide range of habitat conditions above and below the water surface. The constructed wetland is made of recycling filament from PP and PE (HDPE) that has been discussed in the first chapter in order to intake biofilms and to prepare a bed for attracting another micro-organism underwater as well as the defined holds inside the cells designed to support variety plants and marsh grasses to call their home and increase biodiversity.

Aeration; The opened cells operate the role of air delivery pipe in order to transfer fresh air and increase dissolved oxygen levels to ensure the survival of aquatic organisms.

Fig-61. The functionality of the prototype

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Buoyancy; Air-trapped space inside the bottom of cells is considered to keep floating on the surface of the water. furthermore, the proposed wetland should be able to maintain proper levels and stability when exposed to environmental loads like wind, wave, or current loads, so it needs a floating device in order to keep the overall set's buoyancy especially during biomass accumulations. An air-trapped pipe is designed to prevent the sinking of constructed wetland. This mentioned pipe is made of recycled plastic and will be installed at the bottom of the pontoon. It should be noted that this plastic material should be light, soft, and flexible like LDPE from the PE family, in order not to be broken and be able to have reserve buoyancy (Fig-62).

Fig-62. The buoyancy and condition status of the BioInstallation

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3. The digital outcome of the prototype

Fig-63. Conceptual rendering of the BioInstallation

Fig-64. Conceptual rendering of the BioInstallation placement on the water surface

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Fig-65. Conceptual rendering of the BioInstallation in urban pond

Fig-66. Conceptual rendering of the desired biodiversity

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Fig-67. Conceptual rendering of the desired biodiversity

Fig-68. Conceptual rendering of the desired biodiversity

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Fig-69. Biodiversity and ecosystem services goals

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Conclusion

Fig-70. The BioInstallation VS Discarded plastic ocean

Plastic pollution has emerged as one of the most serious environmental concerns, since the world's ability to cope with it has been challenged by the fast-expanding manufacturing of single-use and discarded plastic items. Furthermore, Plastic remains in the environment for a long time, endangering wildlife and spreading poisons. Plastic also contributes to climate change. As well as, it should not be dismissed that negligence is a primary reason, since this pollution is caused mainly by domestic trash that is not properly recycled, dumped in landfills, or abandoned in nature.

This research tries to propose a possible alternative to recycling plastics and help to awareness of this global issue that contributes to better recycling waste management, rising negligence of citizens by trigging them to participate with the municipality for collecting suitable plastic materials inside of defined trash bins next to the garbage bins spots.

This master's thesis concludes that to take advantage of discarded plastic through utilizing additive manufacturing. It is possible that to collect suitable waste plastic for the marine environment, shredded them into pellets, dry them and convert them into recycling filament. The digital system is created to design parametric design output for printing.

The BioInstallation project has the possibility to be used as an alternative recycling approach to contribute to the circular economy of waste plastic via closing the loop on waste plastic and developing a recycled material that can be

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utilized to construct wetland. Wetland constructed from recycled plastic is now used to implement in the environment to increase biodiversity, engaging social interaction and improving ecosystem services rather than damaging natural, endangering landfills, spreading in the ocean, or dumping in a landfill. Then after ending their lifecycle may be ground up and reused in the built environment instead of entering the trash stream and damaging the environment, decreasing our dependency on raw materials.

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