Material Snapshot Recycled Nylon 6. Common Uses In Apparel And Footwear

Transcription

1 Material Snapshot Recycled Nylon 6 Material Scenario Undyed recycled nylon 6 woven textile. General process for chemical depolymerization of waste nylon 6 materials, primarily carpet, for secondary caprolactam and nylon 6 fiber production. Major unit processes include collection of post-consumer waste, sorting, shredding, depolymerization, distilling, melt-extrusion, yarn spinning and textile construction. Data used in this report come from various sources and the scenario is not geographically specific. Common Uses In Apparel And Footwear Due to the fact that recycled nylon 6 is produced from virgin quality caprolactam, it can share many of the same uses as virgin nylon. The manufacturers of EcoNyl have used recycled nylon from fishing nets in apparel including socks, swimwear and underwear (Ditty, 2013). Alternative Textiles That May Be Substituted For Material Virgin nylon 6 Virgin nylon 6,6 Mechanically recycled nylon 6 (Refer to virgin nylon 6 snapshot for other substitutes) Life Cycle Description Functional Unit 1 kilogram of chemically recycled, undyed nylon 6 fabric System Boundary Cradle to undyed woven fabric. The data presented within include all steps required to turn the postconsumer material into woven fabric, including transportation and energy inputs. Capital equipment, space conditioning, support personnel requirements, and miscellaneous materials comprising <1% by weight of net process inputs are excluded. Incineration of waste materials is not included in this study. Allocation Cut-off approach. The first life of the product (e.g. as carpet) is considered entirely separate from the second life (e.g. as a shirt), thus any environmental impacts of producing the waste material used to produce the recycled nylon are allocated entirely to the waste material.

2 2 Unit Process Descriptions Raw Material Sourcing A wide range of nylon waste is generated that can be collected, processed, and recycled into new nylon materials. A significant barrier to efficient collection and recycling is the diversity of nylon materials e.g., nylon 6, nylon 6,6, nylon 6,10, nylon 11, nylon 12, etc. Nylon collection and recycling is most cost efficient when there are large volumes of relatively homogenous waste material (e.g., carpet). Consequently, collection and recycling is mostly nylon 6 and nylon 6,6 waste carpet, with additional waste from virgin nylon production (Gupta and Kothari, 1997, p. 616), fishing nets (Coplare, 2012), and textiles (pre- and post-consumer). None of these materials are collected via multi-material residential curbside collection programs. Rather, these materials are typically obtained through relationships with waste generators or takeback programs such as Interface s ReEntry program (Interface, n.d., Carpet to Carpet Recycling ). Processing Alternative methods for recycling waste nylon materials and products include mechanical extraction (also called melt processing), and various methods of depolymerization followed by repolymerization (Wang, 2006, pp. 2-5). Processors typically choose a method that results in a specified level of output quality for a given waste nylon source. Relatively clean nylon can be depolymerized to provide inputs to polymerization of virgin quality nylon; conversely nylon with some contamination can be melt processed into lower quality nylon (Mihut et al., 2001, p. 1458). Mechanical processing 1 involves cleaning the collected raw recyclate, shredding it into small pieces, densifying the shredded material to increase uniformity, melting the material and extruding the melted material to either form pellets or filaments. Pellets are packaged and shipped to customers that use mechanical means such as injection molding or extrusion to form a wide variety of nylon products. Filaments are formed (whether directly from shredded nylon or from pellets) by extruding the melt through a spinnerette and drawing, twisting, and winding the resulting fibers that can then be processed further into yarn (EOS, n.d. Recycling Nylon Carpet Melt Processing ). Carpets that are shredded and melted without segregating the nylon from the backing material generally require a variety of additives to enhance compatibility of the mixed polymers. Even when segregated, mechanically recycled nylon generally results in a reduction in functional and performance properties (Lozano-González, et al., 2000). Nylon 6,6 is often mechanically recycled, whereas nylon 6 is commonly chemically recycled and can easily be processed back into the same products from which the original recovered nylon originated (Zeftron, n.d., Reclamation & Recycling ). Due to its relatively high value compared with other polymers and because it easily oxidizes in storage resulting in gels when melt processed (Datye, 1991, p. 47), nylon 6 is a good candidate for chemical recycling via depolymerization (Wang, 2006, p. 2, EOS, n.d., Nylon Carpet Recycling Depolymerization ). Similar to mechanical recycling, carpets go through a process of sorting to determine polymer type, shredding, and separation using density techniques of the face fiber (the nylon 6) from the backing (synthetic polymers and/or bio-based materials) (Lu, 2010, pp ). The separated nylon 6 is then batch processed in a depolymerization reactor. The reactor is maintained as a nitrogen-free environment, while the nylon 6 is treated with superheated steam (Wang, 2010, p. 139) at elevated pressure ( kpa) and temperature ( o C) (Braun, et al., 1999, pp. 471; 476; Dmitrieva, 1986, p. 231) to produce an aqueous solution of 10-50% caprolactam (Gupta and Kothari, 1997, pp ). Catalysts such as an alkali (sodium hydroxide), metallic sodium, metal oxides, or phosphoric acid and its salts are used to increase caprolactam yields, although they result in differing levels of purity (Gupta and Kothari, 1997, pp ; Dmitrieva, 1986, p. 230). The aqueous solution of caprolactam can be contaminated with additives used in the original product, such as dyes, lubricant preparations and various fillers (Dmitrieva, 1986, p. 234). To remove impurities, the recovered caprolactam may be distilled in the presence of an aqueous alkali at a temperature of o C (Dmitrieva, 1986, p. 238). 1 Mechanical processing generally includes a melting process and the terms are used interchangeably.

3 3 Alternatively, impurities may be removed via other methods such as solvent extraction, membrane separation, adsorbants, or oxidizing agents (Gupta and Kothari, pp ). The resulting pure caprolactam is repolymerized into nylon 6 in the same fashion as virgin nylon 6 (see the Nylon 6 Material Snapshot). Whether following directly from polymerization or from melting of pellets, the resulting nylon 6 is extruded through a spinneret typically comprised of mm diameter holes (Mather & Wardman, 2011). The emerging filaments are then extended in jets once they emerge from the spinneret, solidified with water in a quench zone, heated in a steam conditioning process, and treated with a spin finish before they are wound up (Bunsell, 2009 pp ). The fibers are drawn to extend their length, orient the polymer molecules, and improve crystallization to obtain desired properties. While the fibers may be drawn to between 200%-500% of the original length, the higher draw ratios are for technical industrial applications and the lower ratios ( %) are for apparel (Bunsell, 2009, p. 203). After drawing, filaments are subject to twisting, texturing, and heat setting to create the final yarn. There are many levels of heat setting to increase the thermodynamic definition to the morphology throughout the yarn manufacturing process (Bunsell,2009, p. 204). Finally, the yarn is then wound on spinning machines and finally re-wound on bobbins to create the final product (Akovali, 2012, pp ). While nylon 6,6 can be depolymerized, it is not commercially viable due to the nylon 6,6 polymer being derived from two intermediate raw materials: adipic acid and hexamethylene diamine (HMDA) (see the Nylon 6,6 Material Snapshot). Lab depolymerization of nylon 6,6 by several routes has been demonstrated (Patil and Madhamshettiwar, 2014; Duch and Allgeier 2007), but has not been scaled to industrial operations. Textile/ Final Processes Recycled nylon yarn which has been previously wound and spun can be woven into a variety of textiles. Process Inputs Energy Energy is necessary for collection of post-consumer waste (including transport, sorting, shredding, grinding, cleaning), processing (depolymerization, distilling, melt-extrusion, yarn spinning) and textile construction. Cradle to gate production of 1 kg of recycled nylon yarn requires 172 MJ 2 (EcoNyl, 2011, p. 13). Depolymerization and repolymerization processes, filament production, and yarn spinning rather than waste collection and transportation are the major energy using processes (EcoNyl, 2011, p. 13). Weaving was identified by van der Velden, et al. (2014, p. 355) as having the highest impact for polymer fibers when yarns are thin (<70 decitex); they calculated that weaving undyed greige textile (70 decitex) requires 229 MJ (van der Velden, 2014, pp ). 3 Total cradle to gate recycled nylon energy is 401 MJ/kg. Water Process water is used throughout the cradle to gate recycled nylon life cycle, particularly in cleaning the collected waste, steam treatment and post depolymerization purification of caprolactam. Cradle to yarn water use is 84 L/kg. Of this total, collection is 18.5 L/kg recycled nylon yarn and processing is 65.5 L/kg recycled nylon yarn (EcoNyl, 2011, p. 13). Direct use of water weaving is minimal (unless water jet weaving is used). However, water use is embedded in electricity production (approximately L/MJ) leading to an estimated 5 L of water per kg of woven textile for the 229 MJ/kg associated with weaving greige textile (Appendix Table B). 2 All reported EcoNyl inputs and outputs data are an average of two EcoNyl products, FDY Raw White and Textured Yarn Raw White (EcoNyl, 2011). 3 As nylon 6 recycling via depolymerization produces virgin quality product, weaving recycled nylon 6 is assumed to be equivalent to virgin nylon 6.

4 4 Chemical Chemical use in collection is limited with occasional use of detergents when cleaning post-consumer waste. Processing requires a range of chemicals depending on the particular depolymerization process method. Substances may include aqueous alkalis, sodium hydroxide, sulfuric acid, phosphoric acid, boric acid, metallic sodium, and metal oxides (Datye, 1991, p. 48; Dmitrieva, 1986, p. 232). Caprolactam purification may be done with solvents such as toluene or other hydrocarbons. The chemistry necessary for polymerization is described in the Nylon 6 Material Snapshot. Additional substances used in yarn and weaving processes include spin finishes, coning oils, titanium oxide, antioxidants, and heat stabilizers (Datye 1991, p. 47). Physical The primary inputs are post-consumer recycled products containing nylon such as carpets fishnets, nylon textiles, and nylon production waste. Land-use Intensity The use of post-consumer nylon products reduces the amount of landfill disposal of carpet and pollution of used fishing nets in the ocean. Because the primary feedstock of the process is post-consumer material, the land required to produce recycled caprolactam is relatively low. Land use is limited to manufacturing facilities. Process Outputs Co-products & By-products After depolymerization, a pot residue is formed on the sides of the reactor, which contains caprolactam and the remains of the catalyst used (Dmitrieva, 1986, p. 232). Caprolactam can be extracted from the pot residue through distillation of water or sulfuric acid (Dmitrieva, 1986, p. 232). The filtrate from this process can also be reapplied in the depolymerization stage of processing (Dmitrieva, 1986, p. 233). All unusable by-products produced from this process are typically burned in an incinerator and the resulting ash is utilized as a filler in various plastic products (Mihut, 2001, p. 1,469). Solid Waste During the sorting and shredding of input post-consumer products such as carpet, the face fiber (nylon 6 or 6,6) is separated from the backing, some of which may be recycled, while the remaining solid waste requires disposal (landfill or incineration for energy recovery). Nylon fibers account for about half of the weight of the post-consumer carpet (Mihut, 2001, p. 1458). After depolymerization, a significant amount of non-volatile waste and by-products remain in the reactor; where available, these are also incinerated for energy recovery (Mihut, 2001, p. 1,461). This waste can include titanium oxide, inorganic salts, tarry products of side reactions, antioxidants, stabilizers etc. (Datye, 1991, p. 48). Nonhazardous solid waste generation averaged 0.7 kg/kg of recycled nylon yarn (EcoNyl, 2011, p. 15). Weaving waste associated with electricity use is 0.9 kg/kg of woven textile. Cradle to gate recycled nylon textile waste is 1.6 kg/kg. Hazardous Waste/Toxicity Hazardous waste generation for recycled nylon 6 yarn is approximately 0.2 kg/kg (EcoNyl, 2011, p. 15). These wastes include hazardous impurities removed from the materials in the depolymerization process as well as hazardous wastes generated in purifying caprolactam and repolymerization.

5 5 Toxic substances in the processing of recovered nylon 6 wastes include the chemicals used in depolymerization (aqueous alkalis, sodium hydroxide, sulfuric acid, phosphoric acid, boric acid, metallic sodium, and metal oxides, etc.) as well as the hydrocarbon solvents that may be used for caprolactam purification (e.g., toluene) Wastewater The production of 1 kg of recycled nylon yarn results in kg PO43- eq. of eutrophication potential (substances that contribute to the exhaustion of oxygen in receiving waters) (EcoNyl, 2011, p. 14). Wastewater generated from the polymerization process or thermoplastic processing may be further purified to obtain pure caprolactam (Losier et al 1995). This wastewater contains 1-20% of solids of which 1-70% by weight is represented by caprolactam that can be catalytically cracked using aluminum oxide to obtain a more pure, concentrated caprolactam (Losier et al, 1995). Emissions The collection and delivery of nylon waste to processors is a minor contributor to emissions EcoNyl, 2011, p. 14). Global warming potential is 7.8 kg CO 2 eq./kg recycled nylon yarn (EcoNyl, 2011, p. 14). Weaving is 10.7 kg CO 2 eq./kg recycled nylon yarn. Cradle to gate recycled nylon textile is 18.6 kg CO 2 eq./kg (Appendix Table D). Table 1. Inputs And Outputs For 1 Kg Nylon 6 Cradle to recycled nylon yarn/ melt spun Recycled nylon yarn to fabric/ undyed textile Cradle to unfinished textile gate Energy (MJ) 172 i 229 ii 401 Water (L) 84 i 5 iii 89 Waste (kg) 0.7 i 0.9 iii 1.6 GHG emissions (kg CO 2 eq, 100 yr) 7.9 i 10.7 ii 18.6 References i EcoNyl 2011, p. 13; 13; 14; 15 ii van der Velden et al., 2014, p. 351 Fig. 10 iii Calculations based on energy data from van der Velden et al (2014) and water values for electricity generation from Boustead, 2005, p. 7 Table 2. Comparison Of Inputs And Outputs For 1 Kilogram Nylon Cradle to Unfinished Textile Gate Recycled Nylon 6 Cradle to Unfinished Textile Gate Virgin Nylon 6 Cradle to Unfinished Textile Gate Virgin Nylon 6,6 Energy (MJ) Water (L) 89 1,653 2,730 Waste (kg) GHG emissions (kg CO 2 eq, 100 yr)

6 6 Performance And Processing Functional Attributes And Performance Abrasion resistant 4 Excellent Tenacity 5 Low moisture absorbency 6 Durable 7 Elastic 8 Resistant to many chemicals 9 Table 3. Mechanical Attributes Of Recycled Nylon 6 Fiber Properties Nylon 6 Recycled Nylon 6 iii Melting temp ( o C) 225 i 220 iv Tenacity (g/d) Tensile Strain (%) 7.2 i 44 iv Tensile Strength (kg/cm²) ii 80 iv Young s Modulus (kg/cm²) i Water retention (%) 1.5 i 1.6 iv References i Akovali, 2010, pp. 123, 135 ii Kipp, 2004, Nylon 6 chart iii A review of the literature did not identify any data on the mechanical attributes of chemically recycled nylon 6 formulated for textile applications; data shown are for a chemically recycled nylon 6 for injection molding applications. iv BASF, 2015 Mechanical Attributes The depolymerization process produces caprolactam, which when repolymerized, creates nylon 6 equivalent to virgin quality nylon (Mihut, 2001 p. 1460). Depending on the types of catalysts used in the depolymerization process, nylon fibers may have lower fiber strength (Mihut, 2001, p. 1463). Processing Characteristics When using chemical depolyermization, post-consumer feedstock can have any variation of molecular weight and chemical contamination without ruining the output caprolactam (Wang, 2010, p. 139). The caprolactam obtained through the depolymerization process is similar to virgin caprolactam in purity (Wang, 2010, p. 139). The quality of secondary caprolactam is improved when the temperature of depolymerization is reduced, however a reduction of temperature also lowers the yield of caprolactam from waste (Dmitrieva, 1986, p. 232). During the depolyermization process, the yield of pure usable caprolactam is a function of the catalyst concentration and the temperature (Dmitrieva, 1986, p. 230). For example, if sodium hydroxide (NaOH) is being utilized as the catalyst, a concentration of 1% can yield 90% pure caprolactam, where comparatively, a concentration of 15% NaOH will only yield 75% output caprolactam (Dmitrieva, 1986, p. 230). Similarly, the yield will increase as temperature increases from o C and decreases thereafter (Dmitrieva, 1986, p. 230). When using phosphoric acid as a catalyst, the yield of caprolactam is directly proportional to the amount of added catalyst (Dmitrieva, 1986, p. 231). Studies have shown that it is possible to obtain reproducible caprolactam yields from the depolymerization of shredded carpet of up to 85% (Elam et al., 1997, p. 994). 4 Akovali, 2012 p135 5 Ibid. 6 Ibid. 7 PlasticsEurope, 2014 p 8 PlasticsEurope, 2014 p 9 Akovali, 2012 p135

7 7 The quality of recycled caprolactam can also vary depending on the various additives used in the original consumer product. For example, if ferric ions are contained in the caprolactam, the fiber strength of resulting recycled nylon 6 will be reduced (Dmitrieva, 1986, p. 235). If impurities are well controlled, the recycled caprolactam can be polymerized into nylon 6 that can be reused for equivalent applications as virgin (USDOE, 2001). Aesthetics The caprolactam obtained through the depolymerization process is similar to virgin caprolactam in purity (Wang, 2010, p. 139). Because of this, the majority of products produced from recycled nylon 6 have similar qualities to those produced with virgin nylon 6. In general, nylon 6 products have good retention of appearance and can be developed in a wide range of colors (Bunsell, 2009, p. 219). Its properties are similar to polyester, though it does wrinkle. The fabrics created from filament yarn are smooth, soft and lustrous (Hegde, 2004, section 9). Potential Social And Ethical Concerns Recycling of nylon 6 avoids the use of benzene and other toxic chemicals required to produce virgin caprolactam. However, several chemicals in the recycling process are toxic, including the use of sodium hydroxide and sulfuric acid. There is a potential for spills or accidents associated with the use of these chemicals in processing plants. Availability Of Material The rate of disposal of carpet ranges from 2-3 million tons per year in the U.S., and 4-6 million tons per year throughout the world (Wang, 2010, p. 137). Of this carpet, 60% is comprised of nylon fibers that are available for recycling (Wang, 2010, p. 137). Carpet feedstock can be collected from landfills, or by companies that collect post-consumer carpet directly following the consumer use phase. Interface has established a post-consumer nylon recycling organization that gathers postconsumer carpets and nylon fishing nets to use in recycled nylon products ( CA/en-CA/about?topic=Recycling). There is the potential for producing an estimated 34 million kg of post-consumer recycled nylon 6 annually according to Lu (2010, p. 69). Aquafil is a supplier based in northern Italy with a depolymerization facility in Slovenia that produces 100% recycled nylon under the brand name EcoNyl ( Around 50% of the recycled content in EcoNyl is from recycled post-consumer carpets and fishing nets. Availability Of Material Nylon specific recycling certifications do not exist. Scientific Certification Systems has a recycled content certification ( and the Textile Exchange Recycled Claim Standard is also available ( Cost Of Textile Reprocessed post-consumer nylon pellets cost around $0.40 per lb over a decade ago (Lave, et al 1998, p. 121). Currently, post-industrial nylon 6 pellets cost between $ per pound (Resource Recycling, 2014, p. 1). Prices for recycled nylon tend to be lower or on par with virgin nylon and fluctuate in conjunction with demand and imports (Resource Recycling, 2014, p. 1).

8 8 Questions To Ask When Sourcing This Material Q: Is the recycled nylon mechanically or chemically recycled? For chemically recycled nylon 6 material: Q: How are by-products and wastes managed from the depolymerization and caprolactam purification processes? Q: Is the nylon 6 polymerized from 100% recycled caprolactam? Q: Are ferric ions found in the post-consumer nylon product?

9 9 Figure 1. System Diagram Of Chemically Recycled Nylon 6 Transportation Post-consumer Nylon Post-consumer Nylon Collection Feedstock Sorting Steam Catalyst e.g. Phosphoric Acid Mechanical Shredding Depolymerization Solid Waste Pot Residue Contaminants From Carpet Aqueous Solution Aqueous Alkali Distillation & Purification Excess Caprolactam Energy Nylon 6 Polymerization Greenhouse Gas Emissions Transportation Melt Spinning Fuel-related Emissions Water Solidifying Transportation Drawing Fuel-related Emissions Winding Transportation Heat Setting Fuel-related Emissions Process Flow Inputs Outputs Weaving 1 kg Undyed Recycled Nylon 6

10 10 Appendix Calculations For Acrylic Table A. Energy For Recycled Nylon 6 Energy EcoNyl Yarn i FDY raw white (MJ) Textured yarn raw white (MJ) Average (MJ) Cradle to yarn ii Weaving (70 dtex) iii Cradle to Gate Undyed Textile Total Notes/ References i All values related to EcoNyl yarn include carpet collection and grinding, depolymerization, re-polymerization, spinning, and texturizing/wrapping ii EcoNyl, 2011, p. 13 iv van der Velden, p. 351 Table B. Water For Recycled Nylon 6 Water Unit Quantity Cradle to yarn water use (average of EcoNyl yarns) i L 84 Weaving water use Weaving energy ii MJ/kg 229 Water use per MJ factor from electricity production iii L/MJ Calculated water use L/kg 5.0 Cradle to Gate Undyed Textile Total L/kg 89.0 References i EcoNyl, 2011, p. 13 ii van der Velden, 2014, p. 351 iii Plastics Europe, 2005, p. 7 Table C. Waste For Recycled Nylon 6 Waste Unit Quantity Cradle to yarn waste (average of EcoNyl yarns) i kg 0.7 Weaving waste use Weaving energy ii MJ/kg 229 Waste per MJ factor from electricity production iii kg/mj Calculated waste kg/kg 0.9 Cradle to Gate Undyed Textile Total kg/kg 1.6 References i EcoNyl, 2011, p. 15 ii van der Velden, 2014, p. 351 iii Plastics Europe, 2005, p. 7

11 11 Table D. GWP For Recycled Nylon 6 GWP FDY raw white (MJ) Textured yarn raw white (MJ) Average (MJ) Cradle to yarn from fossil fuels i Cradle to yarn from bio sources i Weaving (70 dtex) ii 10.7 Cradle to Gate Undyed Textile Total 18.6 References i EcoNyl, 2011, p. 14 ii van der Velden, 2014, p. 351

12 12 References Akovali, Güneri. (2012). Advances in Polymer Coated Textiles. Smithers Rapra Technology. Retrieved from: web/toc.v/cid:kpapct0001/viewertype:toc/root_slug:advances-in-polymer-coated/url_slug:advances-in-polymer-coated?bq=advances%20in%20polymer%20coated%20textiles&sort_on=default&b-subscription=true&b-group-by=true&b-searchtype=tech-reference&b-sort-on=default BASF. (2015). Nypel 2314 HS BK6, Polyamide 6. Retrieved from: php?type=iso&param=nypel+2314+hs+bk6. Braun, M., Levy, A. B., & Sifniades, S. (1999). Recycling Nylon 6 Carpet to Caprolactam. Polymer-Plastics Technology and Engineering, 38(3), Bunsell, A. R. (2009). Handbook of Tensile Properties of Textile and Technical Fibres. Woodhead Publishing (p ). Retrieved from: slug:handbook-tensile-properties?b-q=handbook%20of%20tensile%20properties%20of%20textile%20and%20technical%20 Fibres&sort_on=default&b-subscription=TRUE&b-group-by=true&b-search-type=tech-reference&b-sort-on=default Datye, K. V. (1991). Recycling Processes and Products in Nylon 6 Fiber Industry. Indian Journal of Fibre & Textile Research, 16, 46. Retrieved from: Ditty, S. (2013). From waste to Wear: ECONYL Recycled Nylon is Cleaning Up our Seas. The Ethical Fashion Source Intelligence. Retrieved from: Dmitrieva, L. A., Speranskii, A. A., Krasavin, S. A., & Bychkov, Y. N. (1986). Regeneration of ε-caprolactam from Wastes in the Manufacture of Polycaproamide Fibres and Yarns. Fibre Chemistry, Vol. 17(4): Duch, M. and Allgeier, A. (2007). Deactivation of Nitrile Hydrogenation Catalysts: New Mechanistic Insight from a Nylon Recycle Process. Applied Catalysis A: General, Vol. 318: EcoNyl. (2011). Environmental Product Declaration for EcoNyl Nylon Textile Filement Yarn. Aquafil, synthetic fibers and polymers. CPC code 264. July 1st Retrieved from: Elam, C. C., Evans, R. J., & Czernik, S. (1997). An Integrated Approach to the Recovery of Fuels and Chemicals from Mixed Waste Carpets through Thermocatalvic Processing. Retrieved from: LAS%20VEGAS_09-97_0993.pdf Hegde, R. Raghavendra. Dahiya, Atum. & Kamath M. G. (2004) Nylon Fibers. Retrieved from: pages/textiles/nylon%20fibers.htm Interface. (n.d.). Carpet to Carpet Recycling. Retrieved from: ReEntry-20. Lave, L., Conway-Schempf, N., Harvey, J., Hart, D., Bee, T., & MacCracken, C. (1998). Recycling Postconsumer Nylon Carpet. Journal of Industrial Ecology, 2(1), Lozano-González, et al. (2000). Physical Mechanical Properties and Morphological Study on Nylon-6 Recycling by Injection Molding. Journal of Applied Polymer Science, Vol. 76, Losier, T. P., Johnson, D. R., Fuchs, H., Neubauer, G., & Ritz, J. (1995). U.S. Patent No. 5,458,740. Washington, DC: U.S. Patent and Trademark Office. Retrieved from:

13 13 Lu, D. (2010). Environmental Life Cycle Driven Decision Making in Product Design (Doctoral dissertation, Georgia Institute of Technology). Retrieved from: Mandoki, J. W. (1986). U.S. Patent No. 4,605,762. Washington, DC: U.S. Patent and Trademark Office. Retrieved from: Mather, Robert R. Wardman, Roger H. (2011). Chemistry of Textile Fibres. Royal Society of Chemistry. Retrieved from: knovel.com/web/toc.v/cid:kpctf00001/viewertype:toc/root_slug:chemistry-of-textile-fibres Mihut, C., Captain, D. K., Gadala-Maria, F., & Amiridis, M. D. (2001). Review: Recycling of Nylon from Carpet Waste. Polymer Engineering & Science, 41(9), Patil, D. and Madhamshettiwar, S. (2014). Kinetics and Thermodynamic Studies of Depolymerization of Nylon Waste by Hydrolysis Reaction. Journal of Applied Chemistry, Vol. 2014, Article ID , 8 pages. Retrieved from: org/ /2014/ Plastics Europe. (2005). Electricity Production (on-site). Eco-Profiles of the European Plastics Industry. March. Retrieved from: Retrieved from: plasticseurope.org/plastics-sustainability-14017/eco-profiles/browse-by-list.aspx. Plastics Europe. (2014). Polymide 6 (PA6). Eco-Profiles and Environmental Product Declarations of the European Plastics Manufacturers. February Retrieved from: Resource Recycling. (2014) PetroChem Wire: Nylon 6 Price Falls on Weak Demand. December 18, Retrieved from: resource-recycling.com/node/5518 U.S. Department of Energy, Office of Industrial Technologies. (2001). Nylon 6 Recycling: New Process to Recover and Reuse Nylon Waste. Retrieved from: U.S. Environmental Protection Agency (USEPA). (2015). Carpet. The Environmental Protection Agency. WARM Version 13. Retrieved from: van der Velden, N. M., Patel, M. K., & Vogtländer, J. G. (2014). LCA Benchmarking Study on Textiles Made of Cotton, Polyester, Nylon, Acryl, or Elastane. The International Journal of Life Cycle Assessment, 19(2), Wang, Y. (2006). Carpet Recycling Technologies. Recycling in Textiles, Chicago. Retrieved from: edu/~yw6/fiberrecycling/recycling%20in%20textiles%20ywang%20ch6.pdf Wang, Y. (2010). Fiber and textile waste utilization. Waste and biomass valorization, 1(1), Retrieved from: localnet.abertay.ac.uk/media/fibre_waste_textile_processing_youjiangwang.pdf

14 Developed by: Proudly sponsored by: VF Corporation Prepared in collaboration with: Brown and Wilmanns Environmental, LLC This guide is one of 29 Material Snapshots produced by Textile Exchange in 2015 with financial support from VF Corporation and in collaboration with Brown and Wilmanns Environmental, LLC. They are an extension of the original series released by TE in The content of this snapshot is designed to provide general information only. While every effort has been made to ensure that the information provided is accurate, it does not constitute legal or other professional advice. Textile Exchange cannot be held responsible for the contents of this snapshot or any subsequent loss resulting from the use of the information contained herein. As a continual work in progress, this snapshot will be reviewed on a regular basis. We invite readers to provide feedback and suggestions for improvement, particularly with regards to data where new and improved sources are likely to emerge over time. For more information please [email protected] or visit: Version 1 - January 2016 All rights reserved. Textile Exchange