Welcome Audience

2

PACKAGING MATERIALS : RESEARCH, ADVANCES   AND APPLICATIONS

Dr. K. M. GUPTARetd. Professor (Department of Applied Mechanics)

and ex-Dean(Research and Consultancy),Motilal Nehru National Institute of Technology,

(An Institute of National Importance declared by Govt. of India),

Allahabad-211004, INDIA

Outline• Introduction to packaging and packaging materials.

• Natural fibres and bio-based materials.

• Development and characterization of following bio-based composite materials.

Dual green fibre hybrid composite with different compositions of material system.

Hybrid-composites using banana fibres and banana leaf with epoxy matrix

Fabrication and characterization of human hair reinforced polypropylene composite

• Packaging is the science, art, and technology of enclosing or protecting products for distribution, storage, sale, and use.

• Packaging also refers to the process of design, evaluation, and production of packages.

• Packaging contains, protects, preserves, transports, informs, and sells.

1. Natural Packaging In Different Fruits, Vegetables, and Animals

Orange,Pineapple,Watermelon,Banana,Strawberry,Walnut

Jackfruit, Groundnut, Coconut, Cauliflower Peas, Lemon

Yak Camel Crocodile Hippopotamus Polar Bear

Fig.2 Animals with different kinds of skin covering[2]

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Fig. 3 Some early designed shapes for keeping food items[1] (a) Traditional pot-shaped basket, Mexico, (b) Amphorae, Turkey , (c) Early wooden winebarrel, (d) Blown glass bottle, 3rd century CE 

Historical Packaging Materials

Fig.4 Different cans used for packaging[2]

Fig.5 Glass Bottle for keeping different food items[2]

Traditional Packaging Materials

Fig.6Paper and Cardboard used for food packaging[2]

Fig.7Different rigid plastic packages

Fig.9 Different flexible plastic packaging[2]  

Fig.10 Aluminium foils use. 

Fig.12 Glasses for medicines

Fig.13 HDPE bottles

Fig14. Polypropylene plastic jarsFig.14 Suppositories package

Fig.15 Some common electronic packages

The primary function of any packaging is to protect the product against the environment, to enhance the products life time and conserve its content.

It also means that it can imply the protection of the environment against the packaged product (e.g. for harmful or toxic content).

In either case, packaging provides possibilities to facilitate the transport of the packaged content.

Packaging innovation seeks to increase resource efficiency, eliminate the production of waste and reduce environmental impact through improved design and use of alternative materials.

2. INTRODUCTION TO PACKAGING AND ITS FUNCTIONS

Currently, the raw materials used for packaging are petroleum-based, such as polystyrene and polyethylene etc.

Disposal of used packaging products has become an ecological problem owing to their non-degradability.

The utilization of biodegradable packaging materials has greater potential as eco-friendly material.

The starch is such an alternative raw material for packaging because it is a biodegradable polymer with low cost.

Packaging innovation is all about trying to gain differentiation through truly novel packs that enhance products and therefore make them more appealing to the consumer.

For example, with the availability of technologies allowing the tailoring of material structure at the nano-scale, the next generation of packs will be 'intelligent' ones.

Materials science will also become more and more important to packaging as we continue to look for ways of making packaging materials sustainable yet functional.

A packaging serves the following purposes. (i) Containment of item/ articles/ goods.

(ii) Protection of item/ articles/ goods.

(iii) Convenience.

(iv) Communication.

2.1 Characteristics of a Good Packaging Material

A good packaging material should have the following characteristics.

Excellent tensile and compressive strength to weight ratio, i.e. σ/w ratio.

Cost effectiveness

Good visual and aesthetic appeal

High puncture resistance

It should be re-usable/recyclable

It should be light in weight and easy to use

 It should be versatile for multipurpose wrapping

It should be flame and fire resistant

It should be sealable

It should be flexible to protect all shapes of products

Resistance to moisture absorption

High tear resistance

2.2 Vivid Kinds of Packaging Materials and their Applications

Packaging industry has immensely grown now-a-days. It has acquired important arena in scientific and industrial world. Packaging is widely used for a large variety of applications, the main among them are food packaging, medicine packaging, electronics device packaging, and opto-electronic packaging etc. A large number of food packaging applications are in use, and many more are in process of development. A large variety of packaging are designed for vivid uses. These are

• Multi-material packaging

• Transparent packaging

• Non- transparent packaging

• Corrugated packaging of paper grades, of fluting type, for lining purpose

The packaging materials may be of wide ranges, such as:

Traditional packaging materials

Environmental-friendly packaging materials

Anti-corrosion packaging materials

Anti-moisture packaging materials

Anti-shock and anti-vibration packaging materials

Anti-impact and anti-abrasion packaging materials

The packaging may be meant for the following services.

Export packaging services

Hazardous goods services, etc.

The traditional/conventional materials used in packaging applications are the following.

1. Low density polyethylene (LDPE) 2. Foam and foam padding

3. High density polyethylene (HDPE) 4. Aluminium foils and rolls

5. Bubble wrap and film cushioning 6. Polystyrene

7. Paper and recycled waste paper 8. Timber

9. Desiccants such as silica gel 10. Sealed barrier foil bags 11. Polypropylene, PVC and Vinyl tapes

12. Void fill airbags, paper packaging, loose fill chips etc.

13. Activated clay which protects from water vapour damage, and provides protection in varying climates and temperatures

14. Bubble films which are transparent cellular air packaging material that uses the air trapped inside the polyethylene film as a cushion for protecting products from abrasion, shock and vibration.

2.3 Necessity of Biodegradable Packaging in Food Industry Food packaging and edible films are two major applications of the starch-

based biodegradable polymers in food industry.

The requirements for food packaging include reducing the food losses, keeping food fresh, enhancing organoleptic characteristics of food such as appearance, odour, and flavor, and providing food safety.

Traditional food packaging materials such as LDPE have the problem of environmental pollution and disposal problems.

The starch-based biodegradable polymers can be a possible alternative for food packaging to overcome these disadvantages and keep the advantages of tradi tional packaging materials.

However, the compo nents in the conventional starch-based polymer packaging materials are not completely inert.

The migration of substances into the food possibly hap-pens, and the component that migrates into food may cause harm for the human body. In view of this, new starch-based packaging materials are being developed.

For instance, a starch/clay nanocomposite food packaging material is developed, which can offer better mechanical property and lower migration of polymer and additives[62].

Starch-based edible films are odourless, tasteless, colourless, non-toxic, and biodegradable.

They display very low permeability to oxygen at low rela tive humidity and are proposed for food product protection to improve quality and shelf life without impairing consumer acceptability.

In addition, starch can be transformed into a foamed material by using water steam to replace the polystyrene foam as packaging material. It can be pressed into trays or disposable dishes, which are able to dissolve in water and leave a non-toxic solution, then can be consumed by microbic environment.

3. STARCH BASED PACKAGING MATERIALS Starch based packaging materials are an environmentally-aware

packaging materials with ‘green’ credentials. These are biodegradable loose fill materials produced from starch-based raw materials.

The biodegradable bubble films cushioning are another eco-friendly products whose appearance and performance are very high.

They are free from toxic residues, safe to deposit in landfill where the film is oxo-biodegradable into bio-mass, CO2 and water.

This bubble film can reduce the volume of landfill and pollution also. Starch based packaging materials may be made of different materials and by different processes. Some of them are given below.

Currently, biodegradable packaging offers best for applications of shorter shelf life, high WVTR to prevent condensation, and high oxygen barrier.

The proteins and carbohydrates offer many sites for potential improvement through chemistry.

Also to replace the wide variety of petroleum-based packaging (PS, PP, PE, EVA, etc.), one will need a wide variety of starting materials.

The commodity like fruits: orange, mango, sugarcane etc.; food like: wheat, maize etc. may be used to produce bio-based packaging as follows.

Commodity Product Waste

Fruits and grainsJuice, cheese, flour, vegetable oil, ethanol, bio-diesel etc.

Pulp, peel, glycerol, whey, feather, sugar beet fibres.

From these wastes, the different kinds of bio-based materials/components obtained are

• Composites,

• Film and coatings foils,

• Coatings foils,

• PHA and PLA

• Jars and bottles

• Monomers and biopolymers,

• Boxes, and moulded cups

• Animal oils and bio-glycerol.

3.1 Bio-degradable Packaging from Agricultural Feed Stocks

• These are: pectin based film, edible film and coatings, whey-based packaging, soy-based packaging, straw-based packaging, edible film from dairy proteins, corn-film from extruded films, wheat-based starch moulded packaging, keratin-based packaging.

• The French AGRIPACK company produces packing material

from maize starch.

• The beads obtained are spherical and calibrated at approximately 15-20 mm in diameter. This is shown in Fig. 15

Figure 15 AGRIPACK packing material Figure 16 Edible film and coatings. from maize starch. (Source: Ref. [28]) (Source: Ref. [27] and redrawn)

(a) (b) ( c) ( d)

Figure 17 Various moulded packaging materials. (Source: Ref. [17])

4. FLEXIBLE, ACTIVE AND PASSIVE, AND INTELLIGENT PACKAGINGS

Flexible Packaging. Flexible packaging covers a wide range of packaging that can be single and multi-layered, and is supplied in reels or bags.

It can be paper/poly/foil / nylon/ or a combination of materials which are supplied either plain/printed/coated and/or laminated to provide long shelf life properties.

End products packaging include confectionery, snack foods, frozen foods, soups and pharmaceuticals.

Flexible packages can take a variety of physical forms. Wraps consist of a layer of a material surrounding the product.

It can be classified as intimate wraps, which make direct contact with the product as building wraps and is used to join together two or more products so they can be handled as a single unit.

Stretch wrap functions by utilizing the elasticity of the plastic film. It causes the film to return to its original dimensions when it has been stretched.

Over time, this force decreases due to relaxation within the plastic. Shrink wrap also uses elasticity.

Shrink wrap is commonly used for small wraps, and stretch wrap for longer ones, although both can be used in a variety of sizes.

The sides of the flexible packages can be formed by folding the film using a tube, or by joining two edges together.

Joining is most commonly done by heat-sealing, which requires use of plastic.

Stand-up pouches, one of the most rapidly growing forms of flexible packaging are pouches which, when filled with product, are capable of standing upright on a shelf and can serve as replacements for rigid containers.

Intelligent and Active Food Packaging. Intelligent packaging is emerging as a new branch of packaging technology that offers exciting opportunities for enhancing food safety, quality, and convenience.

A new concept is emerging in which the packaging science, food science, biotechnology, sensor science, information technology, nanotechnology, and other disciplines are coming together to develop a breakthrough in packaging technology.

The advancement in this technology will require researchers to continue to think out new challenges. It monitors the condition of packaged foods to give information about the quality of the packaged food during transport and storage.

Active packaging actively changes the condition of the packaged food to extend life or to improve safety and sensory properties, while maintaining the quality of the packaged products.

Passive Food Packaging. Passive packaging provides protection from external elements such as air and moisture.

This is a traditional packaging that involves the use of a covering material, characterized by some inherent insulating, protective and ease-of-handling qualities.

The most common example of this type of packaging is a simple bio -plastic bag.

4.1 Necessity of Active and Intelligent Packaging

With changes in the way the food products are produced, distributed, stored and retailed; and reflecting the continuing increase in consumers demand for improved quality and extended shelf life for packaged foods, the consumer are placing greater and greater demands on the performance of food packaging. Considering these aspects, innovative active and intelligent packaging concepts are being developed to:

retain integrity and actively preventing the food spoilage i.e enhanced shelf-life enhance the product attributes such as look, taste, flavor, aroma etc. respond actively to changes in product or package communicate product information, product history or condition to user

assist with opening and indicate seal integrity confirm product authenticity and act to counter theft

Opto-Electronics Packaging. Optoelectronics packaging involves maintaining the functionalities of active and passive devices by providing optical and electrical interconnection, mechanical support, and protection from the operating environment to maintain the integrity of the performance. Epoxies are widely used for optoelectronic packaging but there is a need for biocomposite optoelectronic packaging.

5. RECENT ADVANCES IN STARCH BASED COMPOSITES FOR PACKAGING APPLICATIONS

The researches being carried out for the development of starch based composites for packaging applications are focused on different areas. They may be grouped under following categories.

Plasticized starch and fibre reinforced composites for packaging applications.

Starch based nano-composites for packaging applications.

Starch foam, film and coated composites for packaging applications.

Starch based smart (or intelligent) composites for packaging applications.

Jute and Flax-Reinforced Starch based Composite Foams

Egg Albumen-Cassava Starch Composite Films Containing Sunflower-Oil Droplets

6. STARCH AS A SOURCE OF BIO-POLYMER (AGRO-POLYMER) Potato

Sweet Potato

Rice

Wheat

Maize

Cassava

Banana

Barley

Buckwheat

Rye

Taro

Table 2 Starch Content and Nutritional Values of Bio-Polymers per 100g

Item Potato Sweet Potato Rice Wheat Maize Banana

Energy 321kJ 360 kJ 1527 kJ 1506 kJ 360 kJ 371 kJ

Carbohydrate 19g 20.1g 79g 51.8g 19.02g 22.84g

Starch 15g 12.7g 75.8g 71.9g 79.5g −

Sugar − 12.7g 0.12g − 3.22g 12.23g

Fat 2.2g 0.1g 0.5g 0.5g 4.6g 0.016-0.4g

Dietary fibre 0.1-2g 3.0g 1.3g 1.3g 2.7g 2.6g

Protein 75g 1.6g 7.12g 7.12g 10.2g 1.09g

Water1.8mg (14%)

− 11.62g 11g − 68.6-78.1g

Percentages are relative to US recommendations for adults. (Source: Ref [2], Ref [103], nutritiondata.com and USDA Nutrient database).

Figure 5 Starch as a source of bio-polymer (agro-polymer) (Source: Ref. [2])

Figure 7 Starch as a fource of bio-polymer (Agro-polymer) (Source: Ref [2] and Encyclopaedia Britannica)

Figure 6 Distribution of the world banana production (Source : NNCTAD from FAO statistics)

7. FIBRESFibres are classified in different ways such as given below. Natural and synthetic fibres Organic and inorganic fibres Continuous and short fibres Natural fibres such as jute, hump, silk, felt, cotton, flax etc. are obtained from

natural sources such as plants, animals and minerals. Synthetic fibres are produced in industries. They are cheaper and more uniform in

cross-section than the natural fibres. Their diameters vary between 10µm to 100µm.

Bio fibres such as carbon and graphite fibres are light in weight, flexible, elastic and heat sensitive. Inorganic glass, tungsten and ceramic fibres have high strength, low fatigue resistance and good heat resistant.

The strength of composites increases when it is made of long continuous fibres. A smaller diameter of fibres also enhances the overall strength of composite.

7.1 Natural Fibres• Ramie Fibres• Sisal Fibres• Banana Fibres • Jute Fibres• Hemp Fibers•Cotton Fibres •Palmyra Fibres

Figure 8 Ramie plant (Source: http://en. wikipedia.org/wiki/File:Boehmeria_nivea_1.jpg)

Fig. 9a Sisal plant. Fig. 9b Sisal fibre. Fig. 9c Banana tree Fig. 9d Banana fibre (Source: Fig. 9a Wigglesworth & Co. Limited, London SE1 2NY Fig. 9b http://www.matbase.com/material/ fibres/ natural/sisal/properties Fig. 9c http://askpari.files.wordpress.com/2009/06/100_4807_banana_tree.jpg Fig. 9d http://ropeinternational.com/images/ uploaded_ images/banana%20silky%20fibre.jpg)

Fig. 10a. Coir tree. Fig. 10b. Coir-fibre. Fig. 10c. Flax fibre plant Fig. 10d Natural flax fibre (Source: Fig. 10 a http://fida.da.gov.ph/Coco%20tree.jpg Fig. 10b http://product-image.tradeindia.com/00281409/b/0/Coir-Fibre.jpg Fig. 10c-d Ref [27A])

Fig. 11a Jute fibre plant Fig. 11b Natural jute fibre F ig. 11c. Hemp in field Fig. 11d. Hemp fibre (Source: Fig. 11a-b Ref [27b] Fig. 11c http://keetsa.com/blog/wp-content/uploads/2008/09/hemp_field2.jpg Fig. 11d http://www.hempsa.co.za/images/Fibre/ HempFibreRaw.jpg )

Fig. 12a Cotton plant Fig. 12b Cotton fibre Fig. 12c Palmyra tree Fig. 12d Palmyra fibre (Source: Fig. 12a http://www.djc.com/blogs/BuildingGreen/wp- content/uploads/2009/03/cotton-plant.jpg Fig. 12b http://www.diplomatie.gouv.fr/en/IMG/ jpg/trans2_150.jpg Fig. 12c-d Ref. [27c] )

DEVELOPMENT AND CHARACTERISATION OF THE BEHAVIOUR OF A DUAL GREEN FIBRE HYBRID

COMPOSITE WITH DIFFERENT COMPOSITIONS OF MATERIAL SYSTEMS

1. INTRODUCTION Composites made of conventional fibres have a high cost. If made

of cheaper fibres,

they will cut-down the cost of components for which they are used. Natural fibres are such materials.

They are not only cheap, but are abundantly available also. They possess high specific strength and low specific weight, and are ecologically favourable too.

However, their strength is not as high as those of synthetic fibres .Hence, if natural fibre composites are made hybrid with two different kinds of natural fibres, one that has a low density such as flax and other with greater strength.

The resulting dual fibre green hybrid composite is likely to be a blend of lightweight and strong material.

The present work has been undertaken with this aim. The two natural fibres are of flax (Fig. 1a) and palmyra (Fig.2a).

Flax is obtained from flax fibre plant (Fig 1b). Its botanical name is ‘linum usitatissimum’.

It is commonly known as ‘patsan’ which is a substitute of ‘jute’. The flax fibre is strong and wiry, longer and finer in nature.

It lies in the category of bast ( or soft ) fibres.

Figure 1a. Natural flax fibres Figure 1b. Flax fibre plant

Figure 2a. Natural palmyra fibre Figure 2b. Palmyra Tree

Palmyra fibre is also known as `borasus flabellifer`.

It is obtained from a tall and swaying tree(Fig 2b). The word `borasus` is derived from a Greek word.

That describes the leathery covering of the fruit and `flabellifer` means ‘fanbearer’.

2. FABRICATION OF SPECIMEN

Various specimens having the material systems of natural fibre composites and dual natural fibre.

Hybrids have been fabricated using the volume fraction of dual fibres as Vfbres ≈ 54% and volume fraction of polymeric matrix as Vm ≈ 46%.

The dual fibres are mixed in following volume fraction compositions.

All specimens are unidirectional (U/D) i.e. the fibre lay-up is U/D.

(1)100% flax fibres polymeric composite (FPC)

(2) 70% flax + 30% palmyra fibres polymeric fibres hybrid (FPPH)70-30

(3) 50% flax + 50% palmyra fibres polymeric fibres hybrid (FPPH)50-50

(4) 30% flax + 70% palmyra fibres polymeric fibres hybrid (FPPH)30-70

(5)100% palmyra polymeric fibres composite(PPC)

All above compositions of composites/hybrids have been prepared using hand lay- up technique.

For this purpose, an open type mould made of mild steel plate has been used.

A mylar sheet is placed on the lower part of mould to obtain a good surface finish and easy withdrawal of composite from the mould.

In addition to it, the wax is also used to cover the surface of the mould for easy withdrawal of composite.

The weights are hung on both sides to maintain tension in the fibres.

The entrapped air is removed with the help of metal roller rolled on the layer.

3. TESTING OF SPECIMENS

Specimens of different compositions have been tested under tension, compression, bending and impact to characterize their properties.

The testing has been done in accordance with Indian Standard. The tensile test has been performed on Hounsfield tensometer (Fig. 3 ).

The compression test on Universal testing machine,

The bending test on Hounsfield tensometer using the bending attachment, and Impact test on Izod impact testing machine.

Their details are given in subsequent sections.

Figure 3. The experimental set-up showing the Hounsfield tensometer , tensile test specimen, and strain gauge indicator

Tensile Testing: Tensile test is performed on Hounsfield tensometer using the scale range

of 0-1000 kgf (0- 9810 N).

Specimen of size (150 mm length × 30 mm width × 3 mm thickness) has been used.

The stress-strain behaviour of different material systems are shown in Fig. 4.

Figure. 4 Tensile stress-strain curves for flax and palmyra fibre composites and hybrids during tension test.

Compressive Testing: Compression tests have been performed on the specimens of size (25 mm

×25 mm × 30 mm).

The load scale chosen is of 0-2000 kg (0-19.62 kN).

To record strains, a three-element rectangular strain gauge rosette is mounted on the specimen.

Strains are measured with the help of strain indicator.

The compressive testing results are shown in Fig. 5 on stress-strain plot.

Figure5. Comparative stress-strain curves for epoxy, flax and palmyra fibre composites and hybrids during compression test.

Bending Test: Bending test has been performed on the specimen of size (75 mm ×25

mm × 3 mm). The test piece is placed in simply supported position and load is applied

at the centre. Strain is measured by digital strain indicator and deflection is measured

by a dial gauge. Least count of the dial gauge is 0.01mm. To record strains, a three-element rectangular strain gauge rosette is

mounted on the specimen. The results are shown in Fig. 6 on load-deflection plot.

Figure. 6 Comparative load-deflection curves for flax and palmyra fibre composites and hybrids during bending test.

Impact Testing:

• The Impact test has been performed to assess the shock absorbing capacity of different material systems.

• Two types of impact tests viz. Charpy test and Izod test have been conducted.

• In charpy test the specimen is placed as simply supported beam while in Izod test as a cantilever beam.

• Results obtained by testing are presented in Fig. 7 with the help of bar chart.

Figure7. Comparative impact strength (Izod and Charpy) for flax and palmyra fibre composites

Water Absorption Test:Water absorption test is done for different composites.

First the each specimen is weighted and dipped in water and then, after fixed interval the weight is taken.

The weight is taken until the weight of specimen stops increasing or change in weight is minimum.

The weight of specimen is measured using an electronic balance.

Comparative water absorption curves for epoxy, flax and palmyra fibre composites are given in Fig. 8.

Figure8. Comparative water absorption curves for epoxy flaxand palmyra fibre composites

4. SUMMARY OF RESULTS From the above experimental observations,

The following results given in Table 1 are obtained for different material systems.

Specimen →Property ↓

Flax fibre composite(FPC)

Palmyra fibre composite(PPC)

30% Flax & 70% Palmyra composite

(FPPC)30-70

70% Flax & 30% Palmyra composite

(FPPC)70-30

50% Flax & 50% Palmyra composite

(FPPC)50-50

Specific density 1.230 0.930 1.064 1.011 1.132

Tensile strength (kg/cm2 ) 328.88 205.00 233.30 263.30 251.11

Tensile modulus (kg/cm2) × 104 13.51 4.21 5.68 8.13 6.41

Compressive strength (kg/cm2) 975.50 528.16 591.02 833.46 713.46

Bending strength (kg/cm2) 101.92 67.72 75.78 86.24 81.05

Impact

energy

(kg-m)

Izod 0.30 0.20 0.20 0.20 0.30

Charpy 0.30 0.20 0.30 0.20 0.30

Water absorption

( % by weight) 2.70 1.10 1.76 2.10 2.20

Specific tensile strength

(kg/cm2) 267.38 220.43 219.26 260.43 221.82

Specific tensile modulus

(kg/cm2) × 104 10.98 4.53 5.34 8.04 5.66

TABLE 1. MECHANICAL PROPERTIES OF DIFFERENT COMPOSITES

5. CONCLUSION

It is clearly evident that the effect of hybridization is to enhance the tensile strength,

Compressive strength, flexural strength and impact strength as compared to non-hybrid polymeric composites.

Tensile strength increases with increase in percentage of flax fibre and decreases with increase in percentage of palmyra fibre.

Flax fibre composite has higher tensile strength. Tensile strength varies from 205 kg/cm2 (20.5 MPa) which is of palmyra fibre composite, to 328.88 kg/cm2 (32.8 MPa) which is of flax fibre composite.

Compressive strength increases with increase in percentage of flax fibre and decreases with increase in percentage of palmyra fibre.

Bending strength increases with increase in percentage of flax fibre and decreases with increase in percentage of palmyra fibre.

Flax fibre composite has higher flexural strength.

Flexural strength varies from 67.72 kg/cm2 (6.7 MPa) which is of palmyra fibre composite, to 101.92 kg/cm2 (10.1 MPa) which is of flax fibre composite

Impact strength has no noticeable change after addition of fibre.

Impact strength varies from 0.1 kgm to 0.3 kgm.

The specimen with higher flax content has more impact strength.

Water absorption is lowest in palmyra fibre composite and is highest for flax fibre composite.

It increases with increase in percentage of flax fibre. Water absorption varies from 1.1% for palmyra fibre composite, to 2.7% by weight for flax fibre composite.

Hence, it is concluded that the dual green fibre hybrid composites will prove to be a better material system for applications such as small fishing boats, bio-gas containers, grain storage silos,

Light weight machines and equipment, vivid structural elements for low pressure applications such as.

Pipes carrying sewage and industrial waste.

Low strength applications such as tables, boards, panels for partition and false ceiling etc.

REFERENCES

1. K. M. Gupta, Nagarjun, and Rakesh Kumar: Development and characterization of flax-Palmyra fibre reinforced hybrid composite’, M.Tech. thesis, Department. of Applied Mechanics, Motilal Nehru National Institute of Technology, Allahabad, India; and additional work done by K.M. Gupta.