Plastic is something we often use in our daily lives. As small as plastic bags, baby bottles, beverage bottles, lunch boxes, plastic wrap, as large as agricultural film, furniture, electrical appliances, 3D printing, and even rockets and missiles, plastics are all present.
Plastic is an important branch of organic polymer materials, with many varieties, large yields and wide applications. For a wide variety of plastics, they can be classified as follows:
1. According to the behavior when heated, plastics can be divided into thermoplastics and thermosetting sciences according to their behavior when heated;
2. According to the type of reaction during the synthesis of the resin in the plastic, the resin can be divided into polymerized plastics and polycondensed plastics;
3. According to the order state of the resin macromolecules, plastics can be divided into two types: amorphous plastics and crystalline plastics;
4. According to the scope of performance and application, plastics can be divided into general plastics, engineering plastics, and special plastics.
Among them, general-purpose plastics are the most widely used in our daily lives. General-purpose plastics refer to plastics with large production volume, wide supply, low price and suitable for large-scale applications. General-purpose plastics have good molding processability, and can be molded into products for various purposes by various processes. General-purpose plastics include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), acrylonitrile/butadiene/styrene (ABS).
This time I will mainly talk about the main properties and uses of polyethylene (PE). Polyethylene (PE) has excellent processing and use properties, is the most widely used variety in synthetic resins, and its production capacity has long ranked first among all plastic varieties. Polyethylene resins mainly include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE).
Polyethylene is widely used in various countries, and film is its largest user. It consumes about 77% of low-density polyethylene and 18% of high-density polyethylene. In addition, injection molded products, wires and cables, hollow products, etc. all occupy their consumption structure Larger ratio. Among the five general-purpose resins, the consumption of PE ranks first. Polyethylene can be blow molded to make various bottles, cans, industrial tanks, barrels and other containers; injection molded to make various pots, barrels, baskets, baskets, baskets and other daily containers, daily sundries and furniture, etc.; extrusion molding Manufacture all kinds of pipes, straps, fibers, monofilaments, etc. In addition, it can also be used to manufacture wire and cable coating materials and synthetic paper. Among the many applications, the two main consumer areas of polyethylene are pipes and films. With the development of urban construction, agricultural film and various food, textile and industrial packaging industries, the development of these two fields has become more and more broad.
