Textile recycling method

In the first definition, CLR refers to recycling methods whereby the material being recycled is the same material being produced a product enters the production chain of the same product again after use (Klopffer and Grahl, 2014). Under this definition, provided that the waste textile or fibre re-enters a garment production chain, both pre- and post-consumer mechanically recycled textiles may be considered closed-loop recycled. Two approaches are illustrated in Figures 6.2—6.4. 

Virgin nylon fibre, like polyester, is made from crude oil (petroleum). The benefits of recycling nylon come from the reduced energy needed to produce the final fibre, the reduced dependence on oil, and the diversion of waste from landfill. The final product can be recycled again at the end of its hfe. However, due to polymer chemistry, nylon is more difficult to recycle than polyester. There are two main recycling methods explained by the Textile Exchange ... 

A recent technique to achieve a reuse of the thickener is the precipitation of the thickener by addition of organic solvent (e.g., methanol). After removal of the dyes and chemicals the thickener can be reused for the preparation of new pastes. The removed chemicals and dyes are collected and discarded [68]. By this method a considerable part of the COD-forming compounds can be recycled and the AOX and heavy metal content in the wastewater from textile printing can be reduced. 

In order to decrease human consumption of petroleum, chemists have investigated methods for producing polymers from renewable resources such as biomass. Nature Works polylactic acid (PLA) is a polymer of naturally occurring lactic acid (LA), and LA can be produced from the fermentation of corn. The goal is to eventually manufacture this polymer from waste biomass. Another advantage of PLA is that, unlike most synthetic polymers which litter the landscape and pack landfills, it is biodegradable. PLA can also be easily recycled by conversion back into LA. It can replace many petroleum-based polymers in products such as carpets, bags, cups, and textile fibers. 

The appearance of water, especially textile wastewater is systematically described in terms of its visible characteristics (Standard Methods, 1998). In this regard, the presence of color, suspended particles and turbidity is the focus of much of the testing conducted. In the case of textiles, the presence of color in wastewater is extremely important and numerical methods are normally employed to report results from making color assessments. While color in textile wastewater may arise from the presence of transition metal ions, vegetable matter and industrial plant effluents, color derived from unspent dyebaths is of primary importance. Invariably, this color is removed using a number of physical and/or chemical methods (Reife, 1993) however, methods enabling the recycle/reuse of dye-based color have been developed (Reife and Freeman, 1996). 

Another important issue is the EF evaluation of wastes (especially hazardous ones), which are currently discarded in the EF estimates unless they were considered as recycling material when they have an associated natural productivity, while they may become relevant in most production processes. Herva et al. (2010) proposed a method to evaluate the EF of wastes, including hazardous ones, which could be usefiil in the evaluation of textile products however, progress regarding its standardization should be carried out... 

PET bottles to fibre is an OLR method in which PET bottles are recycled into PET flakes, re-spun into fibre and then woven or knitted into textiles. Unlike the method described above, where textile waste enters a second product life cycle, this OLR approach sees waste fi om other product cycles (i.e. bottles from the food and beverage industries) being utilised in textile and apparel production. 

The first section of this study provides an overview of the environmental benefits of clothing recycling and reuse. This is followed by a discussion that defines disposal and how the term is used in this chapter. The statistics for the current situation in Norway for the end-of-life textiles and clothing are presented, followed by a short overview of the literature on clothing disposal practices. Then the two methods that are employed, a wardrobe study and a survey, are presented, followed by results on disposal methods and frequencies. Finally, the implications of the present study are discussed, and suggestions for policy measures and future research directions are suggested. 

The Textile Exchange suggests that three questions should be asked about recycled textiles What is the origin of the waste What is the method of converting waste to chips How does one verify that the product is produced from recycled materials ... 

Mechanical recycling This involves melting waste and re-extruding it into yams. This is the least expensive, lowest energy method and generates the smallest number of impacts. However, there are fewer yam denier/filament options and potential streakiness in dyeing due to impurities. Furthermore, this process can only be done a few times before the molecular stmcture breaks down and becomes unsuitable for textiles. 

Effluent is associated not just with many process industries, as has been illustrated above in the case of the textile finishing industry, but also with most aspects of our urban existence. The need to treat effluent arises for several reasons. Some effluents can be transformed into useful products, such as feedstock for animals or even pharmaceutical products the ability to concentrate effluent, particularly in an energy-efficient manner, can reduce disposal costs and the ability to recycle effluents, once separated from less desirable components, can also be economically beneficial. The link between effluent treatment and PI is strong and growing, as the above influences become the subject of legislation or economic necessity. The range of techniques that can be used to aid clean-up covers both active and passive intensification methods. Included below are several examples including the use of ultrasound already dealt with in a number of process uses in this chapter. 

Methods of biological utilisation of polyester/cellulose textile blends are based exclusively on the application of cellulolytic enzymes, like cellulases, catalysing the hydrolytic degradation of cellulose to a sugar mixture like glucose or ceUobiose. The recovered polyester components were tested to be recycled in the melt process. ... 

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