POM (Polyoxymethylene) polyoxymethylene (POM), POM POM scientific name polyethylene oxide POM (or POM), also known as Race Steel, Special Steel. It is based on the aggregate proceeds of formaldehyde as raw materials. POM-H (POM homopolymer), POM-K (POM copolymer) is a high density, high degree of crystalline engineering thermoplastics. Has good physical, mechanical and chemical properties, especially excellent rub resistance. POM is a no no side chain, high-density, high-crystalline linear polymer with excellent overall performance. POM is a surface smooth, shiny, hard and dense material, yellow or white, long-term use in the temperature range of -40 - 100 ° C. Its wear resistance and lubricity superior than most other engineering plastics, there are good oil, peroxide-resistant performance. Very acid, of intolerance alkali and impatience UV radiation. 
 Physical properties 
 POM of the tensile strength up to 70MPa, water absorption, dimensional stability, glossy, these performance than nylon, POM is a highly crystalline resin in the thermoplastic resin is the toughest. With the thermal strength, flexural strength, fatigue resistance are high strength, abrasion resistance and excellent electrical properties. POM performance: the performance values ??for specific gravity 1.43 Melting point 175 ° C tensile strength (yield) 70MPa 15% of the elongation rate (yield) (Break) 15% of the impact strength (unnotched) 108KJ/m2 (notched) 7.6KJ/m2 
 Range of applications 
 POM is a crystalline plastic, melting point significantly, once they reach the melting point, melt viscosity decreased rapidly. Heating time is too long when the temperature exceeds a certain limit or melt, it will cause decomposition. POM has good overall performance, thermoplastic is the hardest, is one of the plastic material closest to the mechanical properties of metal species, and its tensile strength, flexural strength, fatigue resistance, abrasion resistance and electrical properties are has an excellent long-term use between -40 degrees - 100 degrees. 
 Chemical properties 
 According to the molecular chain structure, POM POM acetal copolymer, the former density, crystallinity, high melting point, but poor thermal stability, narrow processing temperature (10 degrees), the stability of pH is slightly lower; the latter density, crystallinity, low melting point, but the good thermal stability, not easily broken down, the processing temperature (50 degrees) downside is that: by acid corrosion, poor weather, poor adhesion, thermal decomposition and softening temperature close limiting oxygen index is small. They are widely used in automotive, electronic appliances, machinery and equipment. You can also do the taps, box windows, wash basin. POM Characteristics: Density g / cm3 1.39 
 Water absorption% 0.2 
 Continuous Use Temperature ℃ -50 - 110 
 Tensile strength at yield MPa, 63 
 Yield tensile strain of% 10 
 Ultimate tensile strength in MPa 

 Ultimate tensile strain of% 31 
 Impact toughness Kj / m 

 Notched impact toughness Kj / m 6 
 Rockwell hardness MPa, 135 
 Shore hardness MPa, 85 
 Flexural Strength MPa 

 Modulus of elasticity MPa, 2600 
 Softening temperature ℃ 150 
 Heat distortion temperature HDT ℃ 155 
 Hotline coefficient of expansion 
 1.1 
 Thermal conductivity of 031 W / (m × K) 
 Coefficient of friction 
 0.35 
 POM has a low coefficient of friction and the geometric stability, particularly suitable for the production of gears and bearings. It also has a high temperature characteristics, it is also used for pipe device (pipe valve, pump housing), lawn equipment, etc.. POM products 
 Process conditions 
 Dried: If the material is stored in a dry environment, usually do not need to be dried. The melting temperature: homopolymer materials for 190 ~ 230 ℃; copolymers for 190 ~ 210 ℃. Mold temperature: 80 ~ 105 ℃. In order to reduce the molding shrinkage can choose a higher mold temperature. Injection pressure: 700 ~ 1200bar injection speed: moderate or high injection speed. Runners and Gates: You can use any type of gate. If you are using a tunnel-shaped gate, it is best to use the shorter type. Homopolymer materials recommended using the hot nozzle flow. Copolymers can use within the hot runner can also use external hot runner. Chemical and physical properties of POM POM: POM is a tough, flexible material, even at low temperatures is still a very good anti-creep properties, geometry, stability and impact resistance. POM both homopolymer materials and copolymer materials. Homopolymer material with an extension strength, fatigue strength, but can not be easily processed. The copolymers have good thermal stability, chemical stability and ease of processing. Both homopolymer material or copolymer materials are crystalline materials and are not easily absorb water. The high degree of crystallinity of the POM cause it has a very high shrinkage, can achieve a high 2% to 3.5%. For a variety of enhanced materials have different shrinkage rates. 


 POM unique place is its toughness and hardness close to metal, high temperature wear resistance is also relatively good, do gear and wear parts