Usage allocation
The injection molding products used in Europe and America account for 50% of the total consumption, mainly used as parts of automobiles and electrical appliances, various containers, furniture, packaging materials and medical equipment; Film accounts for 8%~15%, and polypropylene fiber (commonly known as polypropylene fiber in China) accounts for 8%~10%; Pipes and plates used for construction account for 10%~15%, and others account for 10%~12%. At present, 40%~45% of China’s knitting products are used, followed by about 40% of film and injection products; Polypropylene fiber and others account for 10%~20%.
Polypropylene is mainly used in food packaging, household goods, automobiles, optical fiber and other fields in China. The largest field of polypropylene used in China is woven bags, packaging bags, strapping ropes and other products, accounting for about 30% of the total consumption. In recent years, with the development of polypropylene injection molding products and packaging films, the proportion of polypropylene used for weaving products has decreased, but it is still the area where polypropylene is consumed most. Injection molding products are the second largest consumption area of polypropylene in China, accounting for about 26% of the total consumption. It is also one of the regions with the largest demand for polypropylene in the future. Another major consumption area of domestic polypropylene is film, which accounts for about 20% of the total consumption, mainly BOPP (biaxially oriented polypropylene film). In the next few years, the proportion of textile products will gradually decline, while the proportion of injection molding products, pipes and plates will increase. According to experts’ prediction on the development of the polypropylene industry, China’s demand for polypropylene is likely to reach about 23.7 million tons by 2020. Textile products, injection molding products and films are still the main demand fields of polypropylene in China, while the annual demand for pipes, plates, fibers and other fields is growing rapidly, and the domestic demand for polypropylene is also growing rapidly. High speed drawing BOPP film, pipe, thin non-woven fabric, high transparent food containers and other special materials have good market prospects.
Machinery and automobile manufacturing parts
Polypropylene has good mechanical properties, and can be directly manufactured or modified to manufacture various parts of mechanical equipment, such as industrial pipes, agricultural water pipes, motor fans, infrastructure templates, etc. The modified polypropylene can be molded into bumpers, anti chafing strips, automobile steering wheel, instrument panel and interior trim parts, which can greatly reduce the dead weight of the vehicle body to save energy.
Electronic and electrical industrial devices
The modified polypropylene can be used to make insulating shells of household appliances and liners of washing machines, and is generally used as insulating materials for wires and cables and other electrical appliances. The polypropylene composite made by mixing 60~80 parts of homopolymer polypropylene, 20~40 parts of ethylene vinyl alcohol copolymer, and 1~10 parts of compatibilizer (the reactant of polypropylene maleic anhydride graft copolymer and ethylene vinyl alcohol copolymer) at 170 ℃~190 ℃ has high toughness, impact strength up to 210J/m, high gas barrier performance, and water vapor permeability rate close to 2000g· μ m/(m2·24h)。 When preparing the barrier film, the traditional film making process can be used. The process is simple and the production cost is low.
construction
Polypropylene fiber is the lightest of all chemical fibers, with a density of (0.90~0.92) g/cm3. It has the advantages of high strength, good toughness, good chemical resistance and microbiological resistance, and low price. Polypropylene reinforced with glass fiber or modified with rubber or SBS is widely used to make building engineering templates. The foamed polypropylene can be used to make decorative materials. In the event of earthquake, the failure mode of polypropylene fiber ceramsite concrete is plastic failure, and there is no fragment peeling. Polypropylene fiber ceramsite concrete is safer than plain ceramsite concrete.
Agriculture, fishery and food industry
Polypropylene can be used to make greenhouse awnings, mulching films, culture bottles, farm tools, fish nets, food turnover boxes, food bags, beverage packaging bottles, etc. The multifunctional waste PET is made by reactive blending with waste PET (polyethylene terephthalate), and the in-situ fiber forming composite is made by in-situ fiber forming composite of multi-functional waste PET and polypropylene. The composite has the structural characteristics of forming profiled microfiber from waste PET, forming a moderately flexible and strong bonding interface between waste PET microfiber and PP matrix resin, etc. The toughness and rigidity of the in-situ fiber forming composite prepared from waste PET and PP are significantly improved compared with PP, and the reproducibility of mechanical properties is quite good. Recycling of waste PET, which is a large amount of waste produced every year in China, has significant economic and social benefits.
In the eastern coastal areas of China, there is a vast sea beach with typical saline soil characteristics. It has been studied that polyacrylamide (PAM) cooperates with three kinds of forages to implement water and soil conservation in coastal saline soil area. PAM was applied under biological measures. It has a good promoting effect on the improvement of soil erosion resistance of the three kinds of forages. PAM application can reduce soil erosion and increase rainwater interception; Give priority to low dosage (1g/m), and its unit mass PAM has the highest water and soil conservation benefit. It can reduce the amount of juvenile erosion by 42.8%~46.7%, inhibit the total amount of soil evapotranspiration by 28.7%~40.4%, increase the amount of soil water loss by 5.0%~12.4%, reduce the rate of water loss by 1.83%~3.25%, and promote the increase of soil water holding capacity; At the early stage of grass growth. Increase rainwater interception by 16.5%~33.8%. The synergistic effect of PAM is beneficial to the inhibition of soil evapotranspiration and the enhancement of rainwater interception capacity.
Textile and printing industry
Polypropylene is the raw material of synthetic fibers. Polypropylene fibers are widely used to make lightweight, beautiful and durable textile products. The images printed with polypropylene materials are particularly bright, bright and beautiful.
Other industries
In the chemical industry, polypropylene can be used to prepare various anti-corrosion pipelines, storage tanks, valves, special-shaped fillers in packed towers, filter cloth, anti-corrosion pump and anti-corrosion container linings; In medicine, it can be used to make medical devices; Polypropylene can also be developed and applied in the energy field through grafting, compounding and blending processes.