The shortening rate of PP sheet is appropriately high, usually ranging from 1.8% to 2.5%. Moreover, the directional uniformity of the shortening rate is much better than that of data such as PE-HD. If 30% glass additive is added, the shortening rate can be reduced to 0.7%. Both homopolymer and copolymer PP materials have moisture resistance, acid and alkali corrosion resistance, and solubility resistance. However, it has no resistance to aromatic solvents such as benzene and chlorinated solvents such as carbon tetrachloride. PP does not have the same antioxidant properties as PE at high temperatures.