Polypropylene, a kind of non-toxic,odorless, tasteless opalescent polymer with high crystallization, the melting point among 164-170℃, the density among 0.90-0.91g/cm3, the molecular weight is about 80,000-150,000. PP is one of the lightest plastic of all varieties at present, particularly stable in water, with a water absorption rate in water for 24 hours is only 0.01%.
