DuPont introduced from the United States of Kevlar-fiber raw materials, processing technology into a special cashmere fibers, and then grinding fibrillation, to the surface of the hair was fluffy plumes, along with many micro-fiber axial fibrillation, a lot of Surface area, has a good absorption, can be very good and moist with resin and filler, the outstanding merits of Kevlar fiber to its thermal stability, it can be 180 degrees Celsius under long-term use, 200 degrees Celsius for 50 hours decrease the strength of only 10 %, 300 degrees when dropped 50 percent, initial thermal decomposition temperatures as high as 500 degrees Celsius, so with this aramid fibers in the friction material products, showing a coefficient of friction stability, low wear rate, the advantages of strength. In addition the use of Kevlar friction material also has good impact strength, products with low-density, low hardness, low-noise braking, the brake does not damage the dual characteristics. Aramid fiber performance indicators are as follows: fineness 2.02 dtex; density g/cm31.4 about surface area m2/g5-8; strong uneven rate of 12.2 percent; stretch uneven rate of 9.7 percent.