Circular Textiles: Closed Loop Fiber to Fiber Wet Spun Process for Recycling Cotton from Denim

Textile waste is a major waste source found in landfills around the world today, due to increases in population, fast fashion cycles, and inefficient recycling technologies. Here we demonstrate a textile recycling process whereby waste denim is dissolved into a binary solvent and a regenerated cellulose fiber is wet spun. We show that using this process the spun fiber can be regenerated whereby the original color of the waste garment is maintained or regenerated in the absence of color. The retention of color can be significant since the regenerated fibers do not need to be redyed, saving considerable water and energy that is typically required in the traditional textile dyeing processes. This process utilized dimethyl sulfoxide (DMSO) as a cosolvent with ionic liquid 1-butyl-3-methylimidazolium acetate ([Bmim]OAc) for the dissolution of the denim waste. The addition of the cosolvent allowed fast dissolution of the cellulosic materials while reducing the viscosity of the spinning dope. The regenerated discolored cellulose fibers produced had similar mechanical properties and morphology to that of viscose fibers, a common regenerated cellulose fiber used extensively in the textile industry. Furthermore, the utilization of binary IL solvent with high DMSO concentration (1:4) reduces the overall process cost. Synopsis: Recycling waste denim creating a regenerated cellulose fiber which can retain the color of the starting textile item or the color can be removed leaving a neutral fiber.