meerlaagse verpakkingen · meerlaagse verpakkingen functionaliteit vs. recycleerbaarheid prof. dr....

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MEERLAAGSE VERPAKKINGEN

FUNCTIONALITEIT VS. RECYCLEERBAARHEID Prof. Dr. Kim Ragaert

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CPMT GROUP

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PLASTICS TO RESOURCE

CO2

H2O

MaTCh DEPARTMENT OF MATERIALS, TEXTILES AND

CHEMICAL ENGINEERING

CENTRE FOR POLYMER AND MATERIAL TECHNOLOGIES

Our mission is to contribute to the circular economy by demonstrating the sustainable potential of plastics.

This is achieved by transferring fundamental materials science to improved industrial processing of recycled plastics.

TEAM RECYCLING

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CAPTURE

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CAPTURE – PLASTICS TO RESOURCE

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Prof. Kim Ragaert

Mechanical Recycling

Prof. Kevin Van Geem

Thermochemical

Recycling

Prof. Steven De Meester

Separation Technology

Prof. Kim Verbeken

High Temp.

Thermodynamics

Prof. Filip Du Prez

Chemical Design for Recyclable

Polymers

Prof. Peter Ragaert

Food Packaging

Prof. Jo Dewulf

Sustainability

Assesment


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RESEARCH MECHANICAL RECYCLING

•  Quality prediction of mixed plastic waste

•  ‘Fit for use’ upcycling

•  WEEE •  Mixed plastics •  Packaging waste

•  Design for Recycling •  Design from Recycling

•  Micro fibrillar composites •  Structure-property

relationships in blends •  Degradation mechanisms •  Compatibilization Fundamental

materials science

Product Design

Resource Efficiency Application

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OUTLINE OF THE TALK RECYCLING OF MULTILAYER PACKAGING FOILS (MPF)

MPF: Why? Where? How much?

Challenges for the recycling of MPF

Science for the effective recycling of MPF

The ReFOIL project

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MPF: WHY?

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Source: Sekisui

Multiple materials are combined into one foil for technical functionality

PET/PE PA/PE

PET/PE/EVOH/PE …

+ tie layers

polymer typical purpose

PE Sealing, H2O barrier, freezable

PP Sealing, H2O barrier, heatable

EVOH Gas barrier

PA Strength, gas barrier, puncture resistance

PET H2O and gas barrier, strength

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MPF: WHERE AND HOW MUCH?

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Post industrial

B2B

clean

Composition (mostly) known

Post consumer

Mixed household

waste

Separate mixed plastic waste

Contaminated (organic and

other plastics)

Composition unknown

Production waste from: •  Foil producer (cutting edges, changeover

rolls, bad products) •  Packager (unfilled trays, leftovers,

cutting edges) •  retailer (unsold food à depackaging)

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MPF: WHERE AND HOW MUCH?

Post industrial

B2B

Numbers hard to come by

Example of foil producing company: 600 tonnes/yr waste

of a single multilayer application

To incineration (or storage)

Post consumer

BE: Currently in mixed household waste

BE: 6% (13.000 tonnes/yr) of total packaging waste

NL, DE: currently in selective plastic waste

NL: 18.000 tonnes/yr PET multilayer

Quite often considered ‘residue’ within this sorting

To incineration

Source tonnage: Fostplus

Source tonnage: KIDV

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The ReFOIL project

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basic principle of mechanical recycling

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CHALLENGES FOR THE RECYCLING OF MPF

grinding

reprocessing

PP boxes 66,5 kg/m³

Flakes 395 kg/m³

For post consumer waste + washing + sorting/separation

parts 890 kg/m³

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Sorting challenges   MPF ‘contaminate’ mono-materials like PET à quality reduction

  Pitfall: NIR recognition of only one ‘side’

à wrongful sorting   However…newer sorting equipment will recognize

‘multilayer’

…so let’s assume we can (or will be able) to sort them out…

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shredding+ compounding

multilayer to multilayer (closed loop) is not self-evident

On top of ‘standard’ challenges related to recycling polymers: Layers cannot be separated into mono-materials

Mechanical recycling turns multilayer into complex blend

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‘POLYMERS DO NOT MIX’

•  Multilayer plastic waste à blend •  Plastics will not mix spontaneously in the melt, not even the ones

that are ‘alike’ like PP-PE

Yeganeh et al, Anomalous phase separation behavior in dynamically asymmetric LCST polymer blends RSC Adv., 2014,4, 2809-12825

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Multilayers will become complex immiscible blends •  Hard to predict exact composition

•  Dominant polymer ( in v%) will most likely form the matrix •  Barrier properties and sealability will be dependent on matrix polymer,

previously thin layers (like EVOH for barrier or PE for sealability) are now dispersed

•  Optical clarity expected to be reduced •  Divergent flow behaviour in processing

•  Mechanical properties will depend on miscibility of the system

‘POLYMERS DO NOT MIX’


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THE EFFECT OF IMMISCIBILITY The mechanical properties of the blend are largely dependent on the miscibility of the system

A.  Synergy in miscible blends (rare!)

B.  (nearly) additive response for immiscible blends (good adhesion)

C.  Grossly immiscible blend: failure due to poor interfacial adhesion

Source: Paul, Polymer Blends: Phase behaviour and property relationships, 1985

Boundaries for B: Eb = ϕ1E1 + ϕ2E2

Eb = E1E2 /(ϕ1E2+ ϕ2E1)

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If you do nothing, they will not mix

Typically (negatively) affected properties: Strength, stiffness, toughness (à impact)


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The ReFOIL project

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SCIENCE FOR THE EFFECTIVE RECYCLING OF MPF

•  Polymer Science vs. the problem of immiscibility •  Mitigate it à use of compatibilizers •  Use it à micro fibrillar composites

•  Product and material design

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MITIGATING THE IMMISCIBILITY

•  Often these blends are composed of an apolar (PP, PE) + polar (PET, PA, EVOH) fractionà immiscibility ñ

•  Improved distributive and dispersive mixing is achieved by reducing interfacial tension between the components

•  A compatibilizer will do this by combining structural elements to achieve interaction with both components

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Example: SEBS-g-GMA as compatibilizer for PET + PP

Source: Re2cycling of compatibilizing agents for recycling, Karen Van Kets

SEBS SEBS

polyester polyester

GMA

polypropyleen

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EXAMPLES OF TYPICAL COMPATIBILIZERS

Backbones • Rubberlike

•  SEBS •  POE

• Polyolefin •  PP

•  PE

Functional groups • Maleic anhydride

• Glycidyl methacrylate

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SEBS


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Compatibilizers reduce interfacial tension and improve dispersive and distributive mixing, thus improving properties greatly

21 Example : addition of 2,5 wt%

SEBS-g-GMA tot 80/20 PP-PET

Van Bruggen, Picken, Koster & Ragaert. Influence of Processing Parameters and Chemical Functionality on the Effective Compat ib i l izat ion of Polypropylene - Poly(ethylene terephthalate) blends. International Polymer Processing, 2016.

Charpy-impact (kJ/m²)

0 10 20 30 40 50

Flex

ural

mod

ulus (

MPa

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800

900

1000

1100

1200

1300

1400

1500

1600

BASE

SEBS2

SEBS2+CA

Ragaert et. al, Design from Recycling: principles and case study. submitted to Polymer Engineering & Science, 2017.

Effect of addition of SEBS and SEBS-g-MA to r(PP-PET) mix

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Micro Fibrillar Composites (MFC)à taking advantage of immiscibility and strengthen matrix (e.g. PP) with second phase (e.g. PET) à Increased strength, toughness and barrier properties

Kuzmanovic, Delva, Cardon and Ragaert. The Effect of I n j e c t i o n M o u l d i n g T e m p e r a t u r e o n t h e Morphology and Properties of P P / P E T B l e n d s a n d Microf ibri l lar Composites. Polymers, 2016

USING THE IMMISCIBILITY à MFC

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Design for Recycling = making it easier to recycle the individual materials making up the product at its end-of life

PRODUCT AND MATERIAL DESIGN

Source: EU Parliament, 2015, Circular economy: the importance of re-using products and materials

•  Reduce the number of layers? •  #materials use vs. recyclability ?

•  Replace high-functionality but difficult-to-recycle materials?

•  Build in a ‘click’ for delamination? •  …

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The ReFOIL project

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REFOIL

RECYCLING OF MULTILAYER PACKAGING FOILS

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VLAIO – TETRA HBC.2017.0056 NOV 17 – OKT 19

SAMEN MAKEN WEMORGEN MOOIER

OVAM

Conhomat bvba

Intersolution bvba

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GOAL The development of effective and efficient pathways for the

mechanical recycling of multi-layer packaging waste.

Packaging waste of interest dominant post-industrial and post-consumer

Research approach includes §  Identification and characterization §  Simulation §  Upcycling §  Design from Recycling strategy §  Realization of demonstrators

Problem statement no current options for mechanical recycling

Mechanical recycling

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PET-PO post-industrial

PA-PO post-industrial

PET-PO post-consumer

MIX post-consumer

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Prof. Dr. Kim Ragaert Sustainable Use and Recycling of Polymers [email protected] +32 9 331 03 91 Ghent University Faculty of Engineering and Architecture MATCH – CPMT Tech Lane A Technologiepark 915 9052 Zwijnaarde, BE

match.ugent.be

www.resourcerecovery.be

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REFOIL project still open for participation

If you are interested in joining the user committee, contact: dr. Laurens DELVA, [email protected]

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