It is commonly referred to as special PU, which refers to ordinary fabrics that have excellent waterproof, oil-proof, and anti-fouling functions after being treated with Dupont's Teflon additives. It is commonly known as the "three-proof", keeping the fabric clean and tidy. According to the washing resistance, it can be divided into ordinary Teflon and super Teflon (Hi-Teflon). Super strong Teflon can still reach 90 points after being washed 20 times, and can reach 100 points before washing, which is almost the same as the effect of lotus leaves.