PP board is a semi-crystalline material. It is harder than PE and has a higher melting point. Because the homopolymer type PP board is very brittle when the temperature is higher than 0℃, many commercial PP boards are random copolymers with 1 to 4% ethylene or clamp copolymers with higher ethylene content.
The PVC board manufacturer Lixin said that the copolymer-type PP board has a lower thermal distortion temperature (100°C), low transparency, low gloss, and low rigidity, but it has stronger impact strength. The strength of PP board increases with the increase of ethylene content. The Vicat softening temperature of PP board PP is 150℃. Due to the high crystallinity, the surface stiffness and scratch resistance of this material are very good. PP does not have the problem of environmental stress cracking. Usually, PVC board manufacturers use glass fiber, metal agent or thermoplastic rubber to modify PP. The flow rate MFR range of PP board is 1~40. PP materials with low MFR have better impact resistance but lower elongation strength.
For materials with the same MFR, the strength of the copolymer type is higher than that of the homopolymer type. Due to crystallization, the shrinkage rate of PP is quite high, generally 1.8~2.5%. And the direction uniformity of shrinkage is much better than that of PE-HD and other materials. Adding 30% of the glass agent can reduce the shrinkage to 0.7%. Both homopolymer and copolymer PP materials have excellent moisture resistance, acid and alkali corrosion resistance, and solubility resistance. However, it has no resistance to aromatic hydrocarbon (such as benzene) solvents, chlorinated hydrocarbon (carbon tetrachloride) solvents, etc. PP does not have oxidation resistance at high temperatures like PE.
