The Chinese name of PP is polypropylene, which is a non-toxic, odorless and tasteless milky white high crystal. PP is one of the five general-purpose resins and is widely used in the automotive industry, household appliances, electrical appliances, electronics, packaging, building materials and furniture. In addition, its derivatives, such as express packaging bags, woven bags, plastic films, pipes and other plastic products, are all commonly used in our daily lives. The downstream of PP can be divided into three main categories: 1. Plastic woven products, which mainly include cement bags, ordinary woven bags, container bags, tarpaulin bags, fertilizer bags, etc. 2. Film products, which can be divided into blown film, cast film (also known as unstretched film, CPP), and biaxially stretched film according to the difference in processing technology. 3. For injection molded products, use an injection molding machine to heat, plasticize and melt the plastic, and then inject it into the cavity of the molding mold for molding. After cooling down, the melt is solidified and then demolded, and the product is injection molded. For example, packaging containers, household appliances parts, children's toys, building materials, auto parts, etc.

Here I will focus on introducing the modified plastic PP polypropylene, which is a thermoplastic resin made by the polymerization of propylene. According to the position of the methyl group, it can be divided into three types: isotactic polypropylene (homopolymer PP), random polypropylene (random copolymer PP) and syndiotactic polypropylene (block copolymer PP). It has the characteristics of homopolymer PP with high crystallinity, high rigidity, chemical resistance, water resistance, abrasion resistance, and excellent dielectric properties. It also has high heat distortion temperature and transparency; impact strength is sensitive to temperature, and low temperature brittleness Large, easy to age under the action of light and heat. Modified plastic PP has many advantages, for example, it is a less dense and cheaper general-purpose plastic. It has good rigidity, transparency, stress crack resistance, chemical resistance, and good bending fatigue resistance. In terms of heat resistance, it is also relatively heat-resistant and has good stability when in contact with water, so it can withstand boiling water cooking; in addition, it has good injection molding processability.

Nothing is perfect, and it also has some shortcomings. I will list them here for you to choose as a basis. The disadvantages of modified plastic PP include: low temperature brittleness, the product is not suitable for low temperature; large shrinkage rate, in other words, the product is easy to deform; poor heat resistance and light aging, if it is not modified, it is not suitable for outdoor use; it is not flame retardant and does not change Can not be used for electronic and electrical parts that require fire protection; narrow melting range, low melt strength, and limited blow molding and molding processing fields; mechanical properties are lower than engineering plastics such as ABS, and it is difficult to apply without modification To engineering structural parts; non-polar polymer, poor coating and silk screen performance.