Melt spinning of sustainable high-quality polypropylene from post-consumer waste for monofilaments

The growing emphasis on sustainability in the textile industry demands innovative solutions for material sourcing and production processes. This study investigates the melt spinning of high-quality polypropylene monofilaments derived from post-consumer waste, focusing on the recycling of food packaging from the plastic waste collection system in Germany. The research explores potential pathways to produce monofilaments that maintain the mechanical properties required for textile applications. Five commercially available polypropylene materials were examined, including a homopolymer polypropylene (hPP) and four recycled polypropylene variants obtained from post-consumer waste. Prior to processing, the materials underwent comprehensive thermoanalytical, rheological, and visual assessments to characterize their thermal stability, flow behavior, and appearance, respectively. The melt-spinning process was carried out by producing monofilaments and evaluating the basic mechanical properties and processability of each material under various process parameters. The mechanical and physical properties of the monofilaments—including tensile strength and elongation—were thoroughly analyzed. Key findings demonstrate that recycled polypropylene can yield monofilaments with mechanical properties comparable to those of virgin materials, highlighting its potential for advanced applications in the textile industry. The study provides valuable insights into the performance and limitations of post-consumer polypropylene in modern melt-spinning processes, contributing to efforts toward more sustainable material use in textile manufacturing.