Polypropylene (abbreviated PP), the second most widely consumed commodity plastic in the world after PE, is a rigid and crystalline thermoplastic polymer used in a wide variety of applications, but often used in packaging and labelling industries. Its properties are similar to PE, but it is slightly harder, more heat resistant and known to have the lowest density among commodity plastics. PP has applications, both as a plastic and as a fiber, in automotive industry, consumer goods, and furniture manufacturing. Homopolymers, Random Copolymers and Hetrophasic (Impact) Copolymer are the three main basic types of PP available in the market.
PP Homopolymer: is the most widely utilized general-purpose grade. It contains only propylene monomer in a semi-crystalline solid form. Main applications include injection molding (automotive parts, thin wall articles, caps and closures, etc.), blow molding, film (BOPP, cast, blown), fiber (CF, BCF, monofilament, nonwoven, staple, raffia, etc.), extrusion (sheet, pipe, profile), and thermoforming applications.
PP Random Copolymer: is produced by polymerizing ethylene and propylene together. These polymers are flexible and optically clear making them suitable of applications requiring transparency and for products requiring an excellent appearance. Typical applications include transparent packaging, injection molding (thin wall items, housewares appliances), blow molding, film (cast, BOPP, Blown), pipe, and thermoforming.
PP Hetrophasic (Impact) Copolymer: containing a co-mixed Propylene Random Copolymer phase, is referred to PP impact copolymer. It is useful in parts which require good impact resistance. Impact copolymers are mainly used in packaging, houseware, film, and pipe applications, as well as in the automotive and electrical segments.