Recycling Textiles: From Post-Consumer Polyester Garments to Materials for Injection Molding

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Engineering

Background:

• The fashion industry generates substantial textile waste, primarily polyester (poly(ethylene terephthalate) - PET).
• Current recycling methods convert garment waste into flakes, but the effect of color sorting on the aesthetic and processability of recycled plastics is not well understood.
• Developing effective recycling strategies is crucial for a circular economy and reducing microplastic pollution.

Purpose of the Study:

• To compare the processability and properties of recycled polyester from dark versus light color-sorted garment flakes.
• To evaluate the efficacy of different chain extenders in improving the properties of recycled polyester during extrusion and injection molding.
• To assess the industrial feasibility of repurposing post-consumer polyester garments for new plastic products.

Main Methods:

• Polyester garment waste was color-sorted into dark and light fractions and converted into flakes.
• Materials were extruded and injection molded, with commercial chain extenders (anhydride, oxazoline, epoxide) added.
• Properties investigated included melt fluidity, injection molding shrinkage, mechanical strength, and thermal behavior.

Main Results:

• Dark-colored recycled polyester showed significant degradation during extrusion, while light-colored material did not.
• All tested chain extenders effectively controlled melt fluidity during reprocessing.
• The bisoxazoline-based chain extender significantly enhanced sample ductility for both dark and light colored materials.
• Reprocessed materials exhibited controlled melt fluidity and improved mechanical properties.

Conclusions:

• Color sorting influences degradation during polyester recycling, with dark materials being more susceptible.
• Chain extenders are effective in managing processability and improving the ductility of recycled polyester, regardless of initial color.
• This recycling approach demonstrates significant potential for the industrial reuse of post-consumer textiles, supporting circular economy principles and mitigating textile waste and microplastic generation.