Melt spinning of reused nylon 6: structure and physical properties of as-spun, drawn, and textured filaments

Polymers are considered to be important environmental pollutants. Polyamide 6 (PA6) is an example of an expensive monomer compared to other polymers. Thus, its recycling seems to be necessary in order to avoid environmental pollution and for the economical reuse of its wastes. To determine the feasibility of industrial processing of waste nylon, new and recycled PA6 chips with different blend ratios were melt spun. As-spun yarns were subjected to drawing and draw-texturing processes. Fiber structure and physical properties of yarn samples were measured and evaluated. Results showed that viscosity and molecular weight of samples with recycled PA6 displayed higher loss compared to the new PA6 fibers after melt spinning. Birefringence of recycled PA6 as-spun yarns was lower than that of new PA6. This difference was compensated by the drawing. In general, noticeable differences were not seen between the fiber structure and tensile properties of new and recycled samples. However, crimp properties of recycled PA6-textured yarn showed higher values than those of new PA6 fibers.