Polypropylene (PP) sheet extrusion is PP resin added with various functional additives is made by extrusion, pressing, cooling, cutting and other processes of plastic sheet. PP plate is a kind of semi crystalline material. It is harder and has a higher melting point than PE. Since the PP temperature of the polymer type is higher than 0, the PP material is a non regular copolymer of ethylene and a higher ratio of ethylene content. The copolymer type PP material has a low thermal distortion temperature (100), low transparency, low gloss, low rigidity, but has a stronger impact strength. The strength of PP plastic plate increases with the increase of ethylene content. PP's VEKA softening temperature is 150. Due to the high degree of crystallinity, the surface rigidity and scratch resistance of this material are very good. PP does not exist the problem of environmental stress cracking. In general, the PP is modified by the addition of glass fiber, metal additive or thermoplastic rubber. PP flow rate of MFR range in 1~40. Low PP MFR material has good impact resistance, but the ductility is lower. For the same MFR, the strength of the copolymer is higher than that of the average. Due to crystallization, the shrinkage rate of PP is high, generally 1.8~2.5%. And the uniformity of the shrinkage rate is much better than that of PE-HD. Add 30% of the glass additives can make the shrinkage rate to 0.7%. Both the polymer and copolymer type PP materials have excellent resistance to moisture absorption, anti acid and alkali corrosion, anti - solubility. However, it is not resistant to aromatic hydrocarbons (such as benzene) solvents, chlorinated hydrocarbons (carbon tetrachloride), etc.. PP is not as high as PE in the high temperature, still has antioxidant properties.