Development of innovative materials and manufacturing methods for sportswear components production.

The growing popularity of cycling has increased the demand for high-performance, cost-effective apparel that ensures comfort during prolonged activity. A critical challenge concerns the cyclist–saddle interface, where body weight support and continuous relative motion generate friction, often causing discomfort or injuries in the ischiatic and perineal regions. Conventional cycling shorts rely on multilayer polyurethane foam (PUF) pads, intended to provide cushioning; however, these are often bulky, insufficiently flexible, poorly ventilated, and prone to heat and moisture accumulation, reducing overall comfort. Modern cycling apparel also requires sustainable solutions. PUFs present recycling challenges due to their complex chemical structure and limited reprocessability. Thermoplastic polyurethanes (TPUs) offer a promising alternative, combining high elasticity, durability, abrasion resistance, and full recyclability via melting and reprocessing. TPUs are well-suited for additive manufacturing such as Fused Deposition Modeling (FDM), which minimizes material waste and allows the production of lightweight, breathable structures with tunable mechanical properties. This research focuses on developing innovative cycling padding using FDM 3D-printed TPUs. By optimizing the internal filling pattern, the padding achieves comfort comparable to conventional PUFs while enhancing mechanical performance. Stress-strain analyses show TPU paddings maintain a consistent elastic response over a wide deformation range, avoiding the plateau caused by foam cell collapse. The study was conducted in collaboration with Cytech Elastic Interface S.p.A., a leading manufacturer of high-performance cycling apparel. FDM printing enables customized geometries, direct deposition onto fabrics without adhesives, reduced emissions, and full mechanical recyclability, improving breathability, durability, and environmental sustainability. Additionally, recycled carbon fiber-reinforced recycled polypropylene composites were investigated. Mechanical and thermal characterization showed properties comparable to virgin fiber composites, confirming the potential of recycled fibers for sustainable high-performance applications and supporting circularity strategies in structural composites.