Coffee Yarn is a functional polyester staple fiber crafted from carbonized coffee grounds. These grounds, after undergoing calcination to form crystals, are then ground into nano-powder and integrated into the polyester fibers. The resulting Coffee Yarn boasts an array of features, including antibacterial and deodorizing properties, negative ion emission, UV protection, thermal insulation, as well as low-carbon environmental benefits. Regarding carbon footprint, it reduces emissions by 48% compared to bamboo and by 85% compared to coconut carbon.