PP is a nontoxic, odorless, odorless, tasteless, creamy, high crystalline polymer with a density of only 0.90 --" 0.91g /cm3, "one of the lightest plastics available. It is particularly stable for water, with a water absorption rate of 0.01% and a molecular weight of about 81,150,000. Good molding performance, but due to large shrinkage rate (1%~2.5%), thick wall products are easy to sag, it is difficult to meet the requirements for some parts with high dimensional precision, and the surface of products is glossy.
