Recycling polypropylene carpets In association with Carpet Recycling

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

Project aims • To develop a process for recycling polypropylene carpets • To assess commercial viability of the process

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

Carpet materials • Polymers: – – Polypropylene (PP); Polyester/Polyethylene terephthalate (PET); Nylon; Chalk-filled elastomers; • Natural fibres: – Wool; and – Hessian/Jute.

Types of carpet - woven • Made by weaving the carpet pile into warp fibres with a loom • Warp fibres can be polyester or PP, whilst the pile tends to be PP http: //www. armelcarpet. com/images/Woven. Diag. gif

Types of carpet - tufted • Pile fibres attached to a backing layer • 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 http: //www. fine-flooring. com/Tufted. Diag. A. gif

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

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

Axion recycling trials • NIR ID sorting • Size reduction • Screening • Extrusion

Size reduction • Granulation – 15 mm screen • Alternative options: – Shearing – Shredding

Granulated PP carpet

Screen to remove dust, fines • High energy flip-flop screen • 12 x 12 mm deck • Alternative technique – dry cleaning

Screening results Target fraction Non-target fraction Losses Oversized Undersized - 38% 59% 3% • Oversized fraction cleaner and less dusty than feed • High yield loss - due to screen size of granulator (15 mm) relative to flip-flop (12 mm) • For 12 mm flip-flop - granulator needs to be 20 -25 mm • For 15 mm granulator screen - flip-flop needs to be 68 mm

Lab scale extrusion • Sorted PP carpet samples: – Post industrial – Post consumer • Material prepared for extrusion by partial melting then granulation

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

Moulded polymer • Post industrial – injection moulding applications • Post consumer – lower grade injection moulding, for example plant pots and buckets

Physical properties test Post industrial sample Post consumer sample 6 52 Mpa 22 23 Elong @ Yield % 7. 3 10. 1 Elong @ Break % 35. 1 28. 8 g/cm 3 1. 15 1. 023 % 17 10 Units MFI (at 230°C, 2. 16 kg) Tensile Density Ash

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.

Overall recycling scheme

Processing option 1

Processing option 2

Payback calculation Option 1 Option 2 Plant capacity tpa 7500 Capital costs £ £ 1, 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 Revenue £/yr £ 1, 940, 000 Margin £/yr £ 833, 900 £ 47, 100 Payback Years 1. 2 17. 0

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

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

Axion Consulting Tudor House Meadway Bramhall SK 2 2 DG 0161 426 7731 info@axionconsulting. co. uk