Polypropylene (PP) is a thermoplastic addition polymer made from the combination of propylene monomers. It is widely used, including consumer goods, packaging, plastic parts and textiles of automobile industry.
Paul Hogan and Robert Banks, scientists of Philips Petroleum Company, first made polypropylene in 1951. Later, Natta, an Italian scientist, also made polypropylene. In 1954, they perfected and synthesized the first polypropylene product in Spain. Their crystallization ability aroused great interest.
By 1957, the popularity of polypropylene had increased dramatically, and extensive commercial production had begun throughout Europe. Today, it has become one of the most commonly used plastics in the world.
It is reported that the current global demand for PP materials is about 76 million tons per year, and it is estimated that by the end of 2023, the demand will It increased to about 90 million tons.
PP is mainly used in the packaging industry, accounting for about 30% of the total consumption. The second is electrical and equipment manufacturing, which consumes about 26%.
Household appliances and automobile industry consume 10% each. The construction industry accounts for 5%.
PP has a relatively smooth surface and can replace some other plastic products, such as gears made of POM and foot mats of furniture.
Smooth surface also makes it difficult for PP to be bonded to other surfaces, that is, PP cannot be firmly bonded with industrial glue, and sometimes it must be bonded by welding.
PP also has low density compared with other plastics, which can reduce weight for users.
It has excellent resistance to organic solvents such as grease at room temperature. But it is easy to oxidize at high temperature.
One of the main advantages of PP is its excellent processability, which can be molded by injection molding or CNC processing.
For example, for PP kit, the lid is connected to the bottle body through a movable hinge. The kit can be directly processed by injection molding or CNC.
The movable hinge connecting the cover is a very thin plastic sheet, which can be bent repeatedly (can move within an extreme range of 360 degrees) without breaking. Although the movable hinge made of PP can not bear the load, it is very suitable for application on the bottle body cap of daily necessities.
Another advantage of PP is that it can be easily copolymerized with other polymers (such as PE) to form composite plastics. Copolymers significantly change the properties of materials, and can achieve more robust engineering applications than pure PP.
Another inestimable application is that PP can be used as both plastic and fiber materials.
The above characteristics mean that PP can be used in a variety of applications: trays, cups, handbags, opaque plastic containers and many toys.