What types of polypropylene are there?
There are two primary types of polypropylene: homopolymer and copolymer. Homopolymer polypropylene is the most common material used. It has a higher tensile strength than copolymer polypropylene and it is less costly. Copolymer polypropylene has higher impact strength but lower tensile strength. It is used for batch tanks that are impacted by the load, for strip tank covers that are handled a lot, and for applications that may be subjected to mechanical abuse. Is polypropylene flame retardant? There are flame retardant grades of polypropylene available. These have various UL ratings. They are more expensive and, because of the addition of the flame retardant fillers, they have lower physical properties and fabricating qualities. Allegheny has developed HY-PRO flame retardant clad copolymer polypropylene. This material has two outside skin sheets of flame retardant polypropylene that are coextruded onto a center core of copolymer polypropylene. Thus providing a composite that is a tough
