Diameter of chopped glass fiber reinforced FRTP performance impact is a complicated problem, table 2-2 for the influence of fiber diameter of the nylon composites.Fiber diameter, in general, the more thin, the higher the strength.But if the fibre diameter is too small, will increase the difficulty of the production, and fine fiber in composite materials, the weak interface will also increase, in the process of machining heavily damaged fiber, strength loss is bigger also.in actual production, usually, we use 7um 10um 10.5um 13um