乐动体育投注app_乐动体育西班牙人_LD乐动体育官网 is a thermoplastic resin prepared by polymerization of propylene. Isotactic polypropylene, atactic polypropylene and syndiotactic polypropylene are three types of propylene by methyl groups.
When methyl groups are arranged on the same side of the main chain of a molecule, it is called isotactic polypropylene. When methyl groups are randomly arranged on both sides of the main chain of a molecule, it is called atactic polypropylene. When methyl groups are alternately arranged on both sides of the main chain of a molecule, it is called metatactic polypropylene. In the polypropylene resin of general industrial production, the content of isotropic structure is about 95%, the rest is random or anisotropic polypropylene. Industrial products are mainly composed of isotopes. 乐动体育投注app_乐动体育西班牙人_LD乐动体育官网 also includes copolymers of propylene and a small amount of ethylene. Usually translucent colorless solid, non - toxic odor. Because of its neat and high crystallization structure, so the melting point can be as high as 167 ℃. Heat resistance, corrosion resistance, products can be steam disinfection is its prominent advantages. Small density, is the lightest universal plastic. The disadvantage is low temperature impact resistance, easy aging, but can be modified to overcome.
Copolymer of PP material with low thermal deformation temperature (100 ℃), low transparency and gloss, low rigidity, but have stronger impact strength, impact strength of PP increased with the increase of ethylene content increased. PP vicat softening temperature is 150 ℃. Due to high crystallinity, the surface stiffness and scratch resistance of this material is very good. There is no environmental stress cracking problem in PP.
The melt mass flow rate (MFR) of PP usually ranges from 1 to 100. PP materials with low MFR have better impact resistance but lower tensile strength. For materials with the same MFR, the impact strength of the copolymerized material is higher than that of the homogenous material. Due to crystallization, the shrinkage of PP is quite high, generally 1.6~2.0%.
Non-toxic, tasteless, small density, strength, stiffness, are better than that of low pressure polyethylene, hardness and heat resistance can be used at about 100 ℃. It has good dielectric properties and high frequency insulation and is not affected by humidity, but it is brittle at low temperature, not wear-resistant and easy to age. Suitable for making general mechanical parts, corrosion resistant parts and insulation parts. Common organic solvents such as acid and alkali have little effect on it and can be used in eating utensils.
乐动体育投注app_乐动体育西班牙人_LD乐动体育官网 has many excellent properties:
1, the relative density is small, only 0.89-0.91, is one of the lightest varieties of plastics.
2, good mechanical properties, except impact resistance, other mechanical properties are better than polyethylene, molding processing performance is good.
3, has higher heat resistance, continuous use temperature can reach 110-120 ℃.
4, good chemical performance, almost no water absorption, and the vast majority of chemicals do not react.
5. Pure texture, non-toxic.
6. Good electrical insulation.
7. The transparency of polypropylene is better than that of hdpe.
It has many advantages but also disadvantages:
1. The products have poor cold resistance and low impact strength at low temperature.
2. The products are easy to be aged by light, heat and oxygen in use.
3. Poor coloring.
4, easy to burn.
5. Poor toughness, high electrostatic, poor dyeing, printing and adhesion.
In recent years, China's household electrical appliances industry has developed rapidly, with a variety of products and a large output. In 2003, China produced 18.5 million refrigerators, 42 million air conditioners, 17 million washing machines and 35 million microwave ovens. It is estimated that the market size of China's home theater system will reach 6.9 million units in the next three years, according to the "research and consulting report on China's urban home theater market from 2004 to 2006". In addition, all kinds of small household appliances also have a huge potential market, which is a great business opportunity for modified PP. Manufacturer of manufacturer of raw material of our country a few plastics already developed washing-machine special makings to be like PP 1947 series, K7726 series, got the welcome of washing-machine manufacturer. Therefore, more efforts should be made to develop PP special materials for household appliances in the next few years to meet the changing needs of the market.
In 2003, China's total plastic pipe production exceeded 1.8 million tons, up by 23% year on year. In the early stage, PP pipes were mainly used as agricultural water pipes, but due to some problems in the early stage product performance (poor impact strength, aging resistance), the market failed to open. As plastic building materials factory in Shanghai the first introduction of foreign advanced technology, using imported conveying cold, hot water in producing pp-r pipe after the approval by market, there have been a lot of pp-r pipe production line, factory construction price also initially commissioned by 20000 ~ 30000 yuan/t fall continuously, but the pp-r pipe in plastic pipe market share is still very low. According to the report, there is a certain gap between domestic pp-r materials and imported materials, the quality needs to be improved and improved. It is reported that South Korea has developed a resistance to high pressure water supply works of random copolymerization polypropylene PP - R 112 new grades, the use of the brand in the production of steel tubes in 20 ℃ and 11.2 MPa using 50 years of ultrahigh pressure condition.
Plastic tubing is one of the focus of the application of chemical building materials products in our country, in 2001, the ministry of construction has issued the "on strengthening copolymerization polypropylene (pp-r, PP - B) pipe production management and application work notice", asked the relevant departments jointly prepared from the raw material, processing, quality and even pipe material use, installation, and work to PP pipe quality, should be strictly and to better prepare the PP pipe production, application and promotion.
High transparent material
As people living standard rises ceaselessly, bring the requirement that changes differently in each respect such as culture, recreation, food, medical treatment, material, bedroom to decorate and raise necessarily, a lot of goods in the market use transparent material more and more. Therefore, the development of transparent PP special material is a very good development trend, especially the need for high transparency, good liquidity, fast molding PP special material, in order to design and process into people's favorite PP products. Transparent PP is more characteristic than common PP, PVC, PET, PS, have more advantage and development prospect.
In recent years, the market of transparent PP has been growing rapidly in foreign countries. Some German companies use transparent PP instead of PVC; The growth rate of transparent PP products in America is 7%~9% higher than that of ordinary PP products. In recent years, the annual dosage of PP nucleating transparent agent in Japan is about 2000t, if calculated by adding 0.25%, the annual output of transparent PP material in Japan can reach more than 800000 t. Japan has the largest consumption of transparent PP materials for microwave cookers and furniture, according to riken. Predict, foreign market is opposite 2005 transparent PP special makings demand is 5 million ~ 5.5 million t about. At present, there is a big gap between domestic and foreign transparent PP special materials, and the production and application of transparent PP resin and its products still need to be strengthened.