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Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

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Page 1: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Recycling polypropylene carpets

In association with Carpet Recycling UK

Funded by Envirolink Northwest

Jane Gardner

Page 2: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Presentation Summary

• Project aims

• Types of carpet

• Current recycling routes

• Demonstration trial results

• Economic assessment

• Project conclusions

Page 3: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Project aims

• To develop a process for recycling polypropylene carpets

• To assess commercial viability of the process

Page 4: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

UK Carpet sustainability

• Over half a million tonnes/year of carpet enters the UK waste stream

• Recycling rate currently less than 2%

• Carpets have high carbon footprint due to use of virgin materials – big sustainability gain if recycled

Page 5: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Carpet materials

• Polymers:– Polypropylene (PP);– Polyester/Polyethylene terephthalate (PET);– Nylon;– Chalk-filled elastomers;

• Natural fibres:– Wool; and– Hessian/Jute.

Page 6: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Types of carpet - woven

• Made by weaving the carpet pile into warp fibres with a loom

http://www.armelcarpet.com/images/WovenDiag.gif

• Warp fibres can be polyester or PP, whilst the pile tends to be PP

Page 7: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Types of carpet - tufted

• Pile fibres attached to a backing layer

http://www.fine-flooring.com/TuftedDiagA.gif

• Pile fibres - wool or PP • Elastomer compound

bonds fibres to the backing layer

• Second backing layer – made from hessian or manmade fibre such as PP

Page 8: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Carpet recycling initiatives

America:

• CARE – Carpet America Recovery Effort – founded 2002

Europe – late 1990’s:

• RECAM - Recovery of Carpet Materials

• CRE - Carpet Recycling Europe

• Polyamid 2000 in Germany

UK – late 2000’s:

• Greenback Recycling

• Reeds Carpets – exhibition/temporary floors

Page 9: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Existing end markets• Typically low value• Equestrian surfaces – additive to sand based all

weather surfaces• Plastic cannot be

recovered once used as equestrian surface

• Other applications:• Horticultural

market

http://www.equestriansurfaces.co.uk/aboutus.html

Page 10: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Axion recycling trials

• NIR ID sorting

• Size reduction

• Screening

• Extrusion

Page 11: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Size reduction• Granulation

– 15mm screen

• Alternative options:– Shearing– Shredding

Page 12: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Granulated PP carpet

Page 13: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Screen to remove dust, fines

• High energy flip-flop screen

• 12x12mm deck

• Alternative technique– dry cleaning

Page 14: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Screening results

• Oversized fraction cleaner and less dusty than feed

• High yield loss - due to screen size of granulator (15mm) relative to flip-flop (12mm)

• For 12mm flip-flop - granulator needs to be 20-25mm

• For 15mm granulator screen - flip-flop needs to be 6-8mm

Target fraction Non-target fraction Losses

Oversized Undersized -

38% 59% 3%

Page 15: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Lab scale extrusion

• Sorted PP carpet samples:

– Post industrial

– Post consumer

• Material prepared for extrusion by partial melting then granulation

Page 16: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Extrusion problems

• Initial batch of carpets could not be extruded

• Presence of un-melted fibres made from different polymers – nylon and PET

• Problem due to different types of carpet – woven and tufted

• Second batch of tufted carpet processed successfully

Page 17: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Moulded polymer

• Post industrial – injection moulding applications

• Post consumer – lower grade injection moulding, for example plant pots and buckets

Page 18: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Physical propertiesPhysical properties

testUnits

Post industrial sample

Post consumer sample

MFI (at 230°C, 2.16kg) 6 52

Tensile Mpa 22 23

Elong @ Yield % 7.3 10.1

Elong @ Break % 35.1 28.8

Density g/cm3 1.15 1.023

Ash % 17 10

Page 19: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Commercial assessment

• Feed stock in Northwest - estimated at over 6,000 tonnes per annum meeting specification of:– Tufted construction;– Positively identified PP pile and backing

fibres;– Dry and with no heavy contamination;– Suitable for manual handling.

Page 20: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Overall recycling scheme

Page 21: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Processing option 1

De-baling stage

Size reduction stage

Screening stage

Yield = 80%

Extrusion stage

Yield = 97%

5000 te/year ofBaled sorted

tufted PP carpet

Cost £80/te

5000 te 4000 te3880 te of PP pelletSell for £500/te

Waste to landfill1120 te

Disposal cost £60/te

1000 te

5000 te

Power costStage operating 8 hours,

5 days a week

Power cost Stage operating 8 hours,

5 days a week

Power cost Stage operating 24

hours, 5 days a week

120 te

Power costStage operating 8 hours,

5 days a week

Page 22: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Processing option 2

5000 te/year ofSorted and size

reduced tufted PP carpet

Cost £250/te

Screening stage

Yield = 80%

Extrusion stage

Yield = 97%

4000 te 3880 te of PP pelletSell for £500/te

Waste to landfill1220 te

Disposal cost £60/te

1000 te

Power cost Stage operating 8 hours,

5 days a week

Power cost Stage operating 24 hours,

5 days a week

120 te

Page 23: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Payback calculationOption 1 Option 2

Plant capacity tpa 7500 7500

Capital costs £ £1,000,000 £800,000

Power £/yr £266,000 £254,800

Labour £/yr £277,000 £241,000

Others £/yr £125,000 £109,000

Total operating costs

£/yr £668,000 £604,800

Feed costs £/yr £400,000 £1,250,000

Disposal £/yr £38,100 £38,100

Revenue £/yr £1,940,000 £1,940,000

Margin £/yr £833,900 £47,100

Payback Years 1.2 17.0

Page 24: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Technical conclusions• Straight forward processing route:

– Rigorous PP identification and sorting

– Size reduction

– Screening

– Extrusion

• Finished PP:

– Good physical properties,

– Suitable for use in medium to low grade applications, Eg injection moulded plant pots

Page 25: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Commercial conclusions

• Critical success factor - correct identification of all polymer fibres within the carpet

• Economics of the recycling process are promising

• Next step: Commercial scale testing

Page 26: Recycling polypropylene carpets In association with Carpet Recycling UK Funded by Envirolink Northwest Jane Gardner

Axion Consulting

Tudor House

Meadway

Bramhall

SK2 2DG

0161 426 7731

[email protected]