Study On The Recycling Of Post-Consumer Polyester Textiles

While the polyester fiber has been increasingly used for variety of applications, its waste in the form of the apparel textiles or nonwovens are increased.,which has been exerted great environment and resource pressures on the sociaty. Factors such as polymer structure degradation, existence of the pigments and other impurities have made the polyester recycling more difficult. Therefore, researches on the process of the polyester fiber recycling have great theoretical and practical significance. In order to simulate the wear and recycling processes of polyester garments, an extrusion melting - SSP (solid-state polymerization) circulating treatment was designed using a min-extruder and a lab scale SSP device. The intrinsic viscosity and spinnability as well as the fiber properties of PETs after each circulation were evaluated.In this paper, solid state polymerization (SSP) method was used to study the intrinsic viscosity (IV) changes of PET-D, PET -H and PET-L in SSP process. In order to study the influence of the pigments on the SSP effects, five polyester chips containing different kind of pigments were prepared and the SSPs were conducted for the five along with PET-D in the same conditions. The influncial factors such as temperature and pigment stypes were studied. The three PETs, namely the virgin PET, recycled PET and PET recycled from PLA uniforms, were spun and the mechanical properties were compared.The PET-H and PET-L were spun and the mechanical properties were comparedThe used PLA uniforms were glycolytically depolymerized using excessive ethylene glycol, then repolymerised in the presence of catalyst and spun. The mechanical properties of the fiber were compared.The results showed that, in the polyester recycle process experiment, the intrinsic viscosity, melting temperature, color (indicated using b and L values) of the polyesters were found detioriated after each circulating treatment. The spinnability and the mechanical properties of the fibers of polyesters after the treatment was getting poorer as the number of cycles increased.The SSP process of the recycled PET followed the same principal as that for the virgin polyesters. Compared to the PET-D, the existence of the pigments had certain effects on its SSP,and the trends for the intrinsic viscosity increase for the five polyester chips containing different kind of pigments were found differenct.The spinning property of the three PETs, namely the virgin PET, recycled PET and PET recycled from PLA uniforms showed that the virgin PET possess the best spinnability and the mechanical properties and the PET recycled from PLA uniforms was the worst.The spinning experiment of the PET-H and PET-L showed that PET-H had better spinnability and the mechanical properties..Compared to the SSP and liquid polymerization, the ferrous fabric undergone glycolytically depolymerized-repolymered and spun, showed a better mechanical property.