Yongmei Group laid the foundation stone for Kaifeng polyformaldehyde project

Polyacetal (English: polyformaldehyde) thermoplastic crystalline polymer. Known as "super steel", it is also called polyoxymethylene. The structure is, the English abbreviation is POM. Usually, the polymer obtained by formaldehyde polymerization has a low degree of polymerization and is susceptible to thermal depolymerization. Around 1955, DuPont polymerized formaldehyde to obtain formaldehyde homopolymer. Polyformaldehyde is easy to crystallize, with a crystallinity of more than 70%. The melting temperature of homopolymer is about 180°C. 　　The scientific name of polyoxymethylene is polyoxymethylene (POM). 　　Polyoxymethylene is a linear polymer with no side chains, high density, and high crystallinity, with excellent comprehensive properties. 　　Polyformaldehyde is a hard and dense material with a smooth and shiny surface, light yellow or white, and can be used for a long time in the temperature range of -40-100°C. Its wear resistance and self-lubricating properties are also superior to those of most engineering plastics, and it also has good oil resistance and peroxide resistance. It is very intolerant to acid, alkali and moonlight ultraviolet radiation. 　　Polyformaldehyde has a tensile strength of 70MPa, low water absorption, dimensional stability, and gloss. These properties are better than nylon. Polyformaldehyde is a highly crystalline resin and is the toughest among thermoplastic resins. It has high heat resistance, bending strength, fatigue resistance, excellent wear resistance and electrical properties. 　　Properties of polyoxymethylene: Performance value Specific gravity 1.43 Melting point 175°C Tensile strength (yield) 70MPa Elongation (yield) 15% (break) 15% Impact strength (unnotched) 108KJ/m2 (notched) 7.6KJ/m2 The synthesis of homopolyoxymethylene is generally based on the condensation polymerization of an aqueous solution of formaldehyde in the presence of acid. A-polyoxymethylene with a degree of polymerization of more than 100 is obtained, which is then heated and decomposed into formaldehyde gas. After purification and dehydration, the monomer is usually purified by partial prepolymerization, and then passed into a dry solvent containing a small amount of initiator for polymerization. Because of the presence of water, the molecular weight is significantly reduced. The initiator can be Lewis acid or alkali. However, most tertiary amines are used for anionic addition polymerization. The reaction is as follows: The terminal group of polyoxymethylene is hemiacetal (-CH2OH). When the temperature is higher than 100°C, the terminal group is easy to break, and it generally needs to be stabilized by terminal group treatment. After stabilization treatment, it can withstand heat up to 230 ℃. Paraformaldehyde can be processed at temperatures of 170 to 200°C, such as injection, extrusion, blow molding, etc. Mainly used as engineering plastics for automobiles, mechanical parts, etc. www.seafar.cn . 　　Typical application areas of POM polyoxymethylene: POM has a very low friction coefficient and good geometric stability, and is particularly suitable for making gears and bearings. Because it also has high temperature resistance, it is also used in pipeline components (pipeline valves, pump housings), lawn equipment, etc. 　　Injection mold process conditions: Drying treatment: If the material is stored in a dry environment, drying is usually not required. 　　melting temperature: Homopolymer material is 190~230℃ ； Copolymer materials are 190~210℃. 　　Mold temperature: 80~105℃. In order to reduce the shrinkage after molding, a higher mold temperature can be used. 　　Injection pressure: 700~1200bar injection speed: Medium or high injection speed. 　　Runners and gates: Any type of gate can be used. If a tunnel gate is used, it is better to use the shorter type. Hot nozzle runners are recommended for homopolymer materials. For copolymer materials, both internal and external hot runners can be used. 　　Chemical and physical properties of POM polyoxymethylene: POM is a tough and elastic material that still has good creep resistance, geometric stability and impact resistance even at low temperatures. POM has both homopolymer and copolymer materials. Homopolymer materials have good ductility and fatigue resistance, but are not easy to process. Copolymer materials have good thermal stability, chemical stability and are easy to process. Both homopolymer and copolymer materials are crystalline materials and do not absorb moisture easily. The high degree of crystallization of POM causes it to have a very high shrinkage rate, which can be as high as 2% to 3.5%. There are different shrinkage rates for various reinforced materials. 　　Polyformaldehyde (pom) is an engineering plastic with excellent performance. It is known as "Dusteel" and "Super Steel" abroad. POM has metal-like hardness, strength and rigidity. It has good self-lubrication, good fatigue resistance and elasticity in a wide temperature and humidity range. In addition, it has good chemical resistance. At a lower cost than many other engineering plastics, POM is replacing some markets traditionally occupied by metals, such as replacing zinc, brass, aluminum and steel to make many parts. Since its inception, POM has been widely used in electronics and electrical, machinery, instrumentation, daily light industry, automobiles, building materials, agriculture and other fields. In applications in many new fields, such as medical technology, sports equipment, etc., pom has also shown a good growth trend. 　　Application consumption continues to grow. POM is used in sliding and rolling mechanical parts that have strict requirements on lubricity, wear resistance, rigidity and dimensional stability. Its performance is particularly superior, so it is mainly used in industrial machinery, automobiles, electronic and electrical, pipe fittings and irrigation supplies. In recent years, my country's pom market has grown rapidly. In 2002, the apparent consumption of pom market in my country was 136,570 tons. From 1990 to 2002, the average annual growth rate of pom market apparent consumption was 11.7%. It is estimated that the apparent consumption of my country's pom market in 2005 will be 168,000 tons, and the average annual growth rate of pom market apparent consumption from 2000 to 2005 will reach 10.3%. By 2010, my country's pom market apparent consumption will increase to 197,000 tons, and the average annual growth rate of pom market apparent consumption from 2005 to 2010 will reach 3.2%. 　　The main factors supporting the rapid development of my country's POM market are: The overall development of the national economy has led to the continuous expansion of the application market of POM, one of the five major engineering plastics, and the increase in usage. ； Raw materials for pom production in my country are cheap and easy to obtain, and pom production and trade are highly profitable. ； New breakthroughs are constantly emerging in the field of pom applications, such as the research and development of modified materials. In view of the steady growth of my country's market demand, the price of pom will continue to maintain a steady and rising trend in the near future. 　　The technological gap cannot be ignored. Although the market demand for POM in my country continues to rise, due to the relatively late development of POM in my country, the production scale, output, variety, and quality of domestic POM have never been able to meet the market demand. Compared with the advanced level of foreign countries, my country's POM production still has problems such as high raw material consumption, small equipment scale, unstable quality, and few varieties and brands. For example, the formaldehyde (37%) per ton consumption of DuPont's homopolymerization process POM is 2.56 tons, and there are reports of 3.08 tons, while the formaldehyde per ton consumption of domestically produced POM is 5 to 6 tons. Although it has been reduced after improvements, the gap is still large. 　　The production capacity and output of my country's POM industry have been low for many years, and the production capacity and output still cannot meet the market demand. In 2002, there were only three POM manufacturers in my country, among which only Yuntianhua Group Company's POM production equipment was 10,000 tons (now expanded to 20,000 tons/year). In 2002, my country's pom production capacity was 12,800 tons/year, with an output of approximately 10,000 tons. From 1966 to 2002, the average annual growth rate of my country's POM production capacity was 16.7%, and the average annual growth rate of output was 18.8%. It can be seen that it is imperative to expand the production capacity of domestic POM manufacturers. It is expected that there will be 6 pom manufacturers in my country in 2005, and the total production capacity will reach 130,000 tons/year. ； It is estimated that my country's pom production capacity will be 190,000 tons/year in 2010, and the average annual growth rate of pom production capacity from 2005 to 2010 will reach 7.9%. 　　The reason why my country's pom production capacity growth cannot meet market demand is that: The domestic pom market is growing rapidly, but the foundation of pom production in our country is relatively weak. ； In addition, POM is a capital- and technology-intensive material chemical product. my country's huge market has attracted the attention of large foreign companies. Foreign companies have always wanted to occupy the Chinese market with their products and are unwilling to transfer technology, making the technical level of domestic POM slowly improve and unable to meet user needs. ； Furthermore, for a long time, our country's economic system and enterprise management mechanism have not conformed to the laws of market economy, and enterprises have been unable to obtain sufficient capital investment in a timely manner, which has restricted the development of POM production. 　　Unbalanced import and export Although my country's pom production has increased, it still cannot meet the demand of the domestic market, and a large amount of pom must be imported every year. The main imports of pom in my country * * and regions include Japan, the United States, South Korea, and Taiwan Province of my country. In 2002, my country's pom import volume was 135,570 tons, and the average annual growth rate of pom import volume from 1995 to 2002 was 26.3%. Our country also exports a small amount of pom every year. In 2002, pom exported 9,000 tons. 　　The development of my country's high-tech industry and emerging industries has greatly increased its demand for engineering plastics. As an engineering plastic that is very suitable for a variety of industries, pom has promising development prospects. It is understood that there are many ongoing POM projects under construction in China. For example, the POM project of DuPont-Asahi Kasei (Zhangjiagang) Company has broken ground, and the proposed POM project of Shanghai Blue Star Chemical New Materials Factory is actively operating. According to the situation of my country's POM proposed projects, it will be the development trend of my country's POM industry to introduce funds and advanced technical equipment to build economic-scale POM devices in locations with raw material foundations and technical foundations. References http://baike.baidu.com/view/323934.htm