Polyethylene terephthalate is the most important variety of thermoplastic polyester, and its English name is Polyhylene.
The abbreviation of pet or petp (hereinafter referred to as pet) is commonly known as polyester resin. It is a polycondensate of terephthalic acid and ethylene glycol. Together with pbt, it is called thermoplastic polyester or saturated polyester.
1946, the first patent for preparing pet was published in Britain, and ici Company in Britain completed the pilot test in 1949. However, after purchasing the patent, DuPont Company of the United States set up a production device at 1953, which took the lead in realizing industrial production in the world. In the early days, pet was almost entirely used in synthetic fibers (commonly known as polyester and polyester in China). Since 1980s, pet has made a breakthrough as an engineering plastic, and successively developed nucleating agent and crystallization promoter. At present, pet and pbt have become one of the five major engineering plastics.
The scale of pet production in China lags far behind that of several major foreign manufacturers. Since 1980s, China has gradually imported 10,000 tons to several hundred thousand tons of advanced pet resin synthesis equipment from abroad, and the quality and output have made great progress. According to the statistics of China Textile Society, China produced 6.5438+0.997 million tons of pet chip resin, including the production capacity of high-viscosity chip resin for packaging (beverage bottles and packaging sheets, etc.). ) is 224,000 tons, so the resin source for producing pet engineering plastics is sufficient. Because the equipment for preparing all kinds of mixed modified pet plastics is common with other polymer mixed modified equipment, the domestic production of mixed extruder has also formed a certain scale, so as long as the market is opened, the domestic production of pet plastics will also grow rapidly.
2. What is a pp box?
Let me talk about it first.
What is pp material:
Pp is the abbreviation of PP, and its Chinese name is polypropylene, commonly known as 100 times glue. Polypropylene is a kind of crystalline isotactic polymer with regular molecular chain arrangement, which is polymerized by propylene monomer under the catalysis of Ziegler-Natta catalyst. Pp (polypropylene) can be divided into isotactic pp (polypropylene) and atactic pp (polypropylene) according to its crystallinity. Isotactic polypropylene is a highly crystalline thermoplastic resin with crystallinity over 95% and molecular weight of 865,438+500,000. Random polypropylene is an amorphous and slightly sticky ash at room temperature, with a low molecular weight of 3000- 10000, irregular structure and lack of cohesion, so it is rarely used. The commonly used pp raw material is isotactic polypropylene.
Modification of pp material (polypropylene)?
Pp (polypropylene) can be modified by filling, reinforcement, * * mixing, * * polymerization and crosslinking. Adding fillers such as calcium carbonate, talcum powder and inorganic minerals can improve the rigidity, hardness, heat resistance and dimensional stability of pp; Adding glass fiber, asbestos fiber, mica and glass beads can improve the tensile strength, creep resistance and low temperature impact resistance; Adding thermoplastic elastomer pe/tpr or rubber can improve the impact performance,
vitrification
In this way, the transparent pp material we want to know is formed.
Application and market prospect of transparent pp material
Polypropylene itself is opaque and easy to crystallize, which makes the product poor in luster and transparency, and the appearance lacks aesthetic feeling, which also restricts the development of polypropylene in transparent packaging, daily necessities and other application fields. After transparent modification, polypropylene can not only inherit its advantages of light weight, low price, sanitation, high temperature resistance and easy processing and molding, but also be comparable to other transparent plastics (such as polycarbonate and polystyrene). ), its cost performance is better than them, so it can be widely used in transparent packaging, medical equipment, household goods, general industry and other fields. In particular, high transparent polypropylene has a wide temperature range, even if it is used in a microwave oven, there is no need to worry that high temperature will damage food packaging and pollute food. At the same time, due to the good flexibility of high transparent polypropylene, the plastic disk made of it is not easy to break and has good sealing performance. It can be predicted that the use of high transparent polypropylene will be the development trend of transparent packaging products. It is understood that the demand for high transparency polypropylene in the international market is more than 3 million tons per year, and the domestic demand is also growing.
Due to the excellent cost performance of transparent polypropylene resin, its market share has increased rapidly. At present, it accounts for 15% of the total consumption of polypropylene products in Japan, and the market demand still maintains a good growth trend.
Compared with ordinary pp, transparent pp has more outstanding properties, especially its excellent transparency and gloss can be comparable to typical transparent materials (such as pet, pvc, ps, etc.). ). Therefore, it can be widely used in medical syringes, food containers, stationery, films, boxes, bottles, household storage equipment, various packaging and other occasions that require high transparency.
3. What is a pvc packing box?
polyvinyl chloride
The full name is, the main component is PVC, which is bright in color, corrosion-resistant, firm and durable. Because some toxic auxiliary materials such as plasticizer and antioxidant are added in the manufacturing process to enhance its heat resistance, toughness and ductility, its products generally do not store food and medicine.