For the recycling of carpet and artificial turf the latex backing is often a real stumble block. Many strategies have been developed like freezing the carpet, followed by grinding and subsequent separation of the milled particles. Once it has been separated from its backing materials, PA 6 is relatively easy to depolymerise. This produces fresh caprolactam that can be used to manufacture PA 6 with no loss in quality, and is suitable for further recycling [1]. The comparable process for PA 6,6 is not as easy, but DuPont and Polyamid 2000 have developed and patented a process that depolymerises any mixture of PA 6 and 6,6 using ammonia. The result is fresh caprolactam and 1,6 diaminohexane for manufacture of PA 6 and 6,6 respectively [2]. Obviously a lot of research has been devoted to avoiding latex as a backing like e.g. polyurethane carpet backing systems based on natural oil polyols and polymer polyols [4]. Still carboxylated styrene butadiene is the leading synthetic latex polymer used in EU-27 for carpet backing, followed by styrene-acrylics and pure acrylics. This contrasts with Eastern Europe, Russia, and Turkey where styrene-acrylics dominate, followed by PVAc and redispersible powders [3]. In addition there has been a lot of research into developing alternative backing systems where the backing can easily be removed. Examples are the use of gecko technology [5] or using click chemistry (reversible Diels Alder reactions) [6]. But the best option for recycling is of course to develop carpets based completely on monomaterials.
 
Paper for the 14th Autex World Textile Conference May 26th-28th 2014, Bursa, Turkey.