Recycling of Denim Waste for Fabrication of Fiber-Reinforced Composites

The accumulation of discarded denim waste in landfills is causing environmental pollution, creating an urgent need for sustainable solutions. This study demonstrates the recycling of denim by extracting the indigo dye and fabricating the treated fabric into a composite to develop eco-friendly and high-performance materials. The waste denim was treated with sodium borohydride under controlled conditions without damaging the fibers. To utilize the denim waste, the decolorized fabric was shredded into fibers and incorporated into two polymer matrices i.e., ethylene vinyl acetate (EVA) and vinyl acetate, (VA) to fabricate a fiber-reinforced composite. The prepared recycled denim composites were compared with composites based on raw cotton fibers. The surface morphology of the composites was studied through optical microscopy and SEM analysis to examine the structural properties. Mechanical tests including tensile, charpy impact, flexural bending and drop-weight tests were performed to evaluate performance. The results showed that the raw composite had a higher impact strength of 11.5 kJ/m2, while the recycled composite had 9.89 kJ/m2, showing a slight reduction but maintaining good mechanical strength and lightweight properties suitable for applications such as table tennis rackets, a sustainable sports product, thereby supporting a closed-loop denim recycling approach within a circular economy framework.