Carpet recycling

DSM and Allied Signal have developed carpet identification equipment that can identify specific plastics. Particularly carpet made of nylon 6 (or nylon 66) fibres are separated, cut into pieces, isolated, and converted by polycondensation into their monomeric components. The monomers can then be reused in the production of nylon. DSM and Allied Signal opened the world s first large scale carpet recycling plant in Augusta, Georgia, US in November 1999. This plant has a capacity of 90,000 tpa nylon 6 carpet waste (109). 

The problem of carpet recycling is considered and the different methods being proposed or commercially utilised are discussed. The main component of the carpet waste is fibres of nylon-6 and nylon-66. The review of the literature includes a limited amount of journal publications, which focus primarily on fundamental aspects, and a large number of patents, which describe the available technologies. The most promising recycling techniques (depolymerisation, extraction, melt blending and mechanical separation) are described. 48 refs. 

FIRST LARGE-SCALE CARPET RECYCLING PLANT... 

NYLON SUPPLIERS TAKE LEAD IN CARPET RECYCLING... 

CARPET RECYCLING OEEERS MARKETING ADVANTAGE TO NYLON... 

The Polyamid 2000 plant in Premnitz, Germany is another nylon 6 carpet recycling facility. For an investment of US 200 million in 2000, the plant was designed to process 264 million pounds per year of carpet and produce 20 million lb/yr of nylon 6 plus 25 million pounds of nylon 6,6 and other engineering plastics271. 

In May 2002 the plant was only running at 75% of capacity (15 million lb/yr of nylon 6). One problem was that the nylon content in the carpet was lower than expected. Another problem is that landfill fees have dropped from 90/ton to 45/ton. It is estimated that landfill fees must be at least 75/ton for carpet recycling to be viable271. 

Realff, M. J., Ammons, J. C., and Newton, D. (1999), Carpet Recycling Determining the Reverse Production System Design, Journal of Polymer-Plastics Technology and Engineering, Vol. 38, No. 3, pp. 547-567. 

McNeil, S.J., Sunderland, M.R., Zaitseva, L.I., 2007. Closed-loop wool carpet recycling. Resources Conservation and Recycling 51, 220—224. 

As the search of technology for carpet recycling continues, carpet also is being redesigned for better recyclability. Reuse of reconditioned carpet is being considered for extending its life. 

C A developed a closed-loop process for recycling postconsumer carpet and manufacturing waste into recycled content backing for new carpet. Recycled content ranges from 31 percent to 52 percenL and the material is recyclable back into carpet at the end of itshfe.2< ... 

A number of other companies either are or have been engaged in nylon (or other) carpet recycling programs. 

Nylon recycling has increased substantially in the last several years. Most recycling efforts have focused on recovery of carpet. According to the U.S. Department of Energy, about 3.5 billion lb of waste carpet are discarded each year in the United States, with about 30% of them made from nylon 6. (For more on carpet recycling, see Sec. 12.4.15.) Recycling systems for condensation polymers, such as nylon and PET, can more effectively use chemical depolymerization techniques than can systems for addition polymers such as polyolefins and PVC. Most of the efforts directed at nylon recycling have taken this route. 

In Minnesota, over 60 businesses, along with government groups and the University of Minnesota participate in the Minnesota CA-RE (carpet recycling) Program. Some of the collected material is used by... 

U.S. Department of Energy, Waste Carpet Recycling, available online at www.oitdoegou / chemicals / citar96 / CITAR96p31. htm, 1998. 

In the same timeframe, Polyamid 20(X) announced plans to open an integrated carpet recycling facility in Premnitz, Germany. This would be a 2(X) million investment associated with the old East German sector and was designed also to provide jobs in this region. Carpet would be collected around Europe aud shipped... 

Table 5.1 General approach for estimation of carpet recycling volumes and Atlanta case study...

Systems planning for carpet recycling 53 Table 5.3 Baling and shipping model definitions... 

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