Mainly used for the production of various long and short polypropylene fibers, used for the production of polypropylene woven bags, packaging bags, injection molded products, and other flame-retardant components for electrical appliances, telecommunications, lighting, lighting equipment, and televisionsDongbiao Testing Center reminds that there is no environmental stress cracking issue with PP. Usually, PP is modified by adding glass fiber, metal additives, or thermoplastic rubber. The flow rate of PP has an MFR range of 1-40. PP materials with low MFR have better impact resistance but lower tensile strength. For materials with the same MFR, the strength of copolymer type is higher than that of homopolymer type. Due to crystallization, the shrinkage rate of PP is quite high, generally ranging from 1.8 to 2.5%. And the directional uniformity of shrinkage rate is much better than materials such as PE-HD. Adding 30% glass additive can reduce the shrinkage rate to 0.7%. Both homopolymer and copolymer type PP materials have excellent resistance to moisture absorption, acid and alkali corrosion, and dissolution. However, it has no resistance to solvents such as aromatic hydrocarbons (such as benzene) and chlorinated hydrocarbons (carbon tetrachloride)
