The shrinkage of POM crystalline plastics is related to mold temperature, product wall thickness and post-treatment. The crystallization speed of the material is certain. The thicker the thickness, the higher the mold temperature (of course not too high), the longer the crystallization time (under the same conditions), the higher the crystallinity (basically proportional, the influence will gradually decrease when reaching a certain temperature), and the smaller the shrinkage. Of course, specific to the injection molding process, there will be other factors that affect the shrinkage rate.

It has good physical, mechanical and chemical properties, especially excellent friction resistance. Commonly known as Saigang or Duogang, it is the third largest general engineering plastic. Suitable for manufacturing wear-resistant parts, transmission parts, chemical and instrument parts.

One of synthetic resins, also known as polyoxymethylene resin, polyoxymethylene plastic, Saigang material, etc. It is a white or black plastic particle with high hardness, high rigidity and high wear resistance. Mainly used in gears, bearings, auto parts, machine tools, instruments and other products that play a skeleton role.

Extended data:

POM has good electrical insulation and is almost unaffected by temperature and humidity. In a wide range of temperature, humidity and frequency, the dielectric constant and dielectric loss change little. Excellent arc resistance, can be maintained at high temperature. The dielectric strength of POM is related to the thickness, which is 82.7kV/mm when the thickness is 0. 1.27mm and 23.6kV/mm when the thickness is1.88 mm. ..

POM is not resistant to strong alkali and oxidant, but it is stable to alkenoic acid and weak acid. POM has good solvent resistance, resistance to hydrocarbons, alcohols, aldehydes, ethers, gasoline, lubricating oil and weak alkali, and can maintain considerable chemical stability at high temperature. Small water absorption and good dimensional stability.

POM has poor weather resistance. Under the action of ultraviolet rays for a long time, the mechanical properties decreased and the surface cracked.

Polyoxymethylene has high strength and stiffness, good elasticity and good wear resistance. Its mechanical properties are excellent, the specific strength can reach 50.5MPa, and the specific stiffness can reach 2650MPa, which is very close to metal.

The mechanical properties of POM have little change with temperature, and the change of * * * poly POM is slightly greater than that of homopolymer POM. The impact strength of POM is high, but the conventional impact is not as good as ABS and PC. POM is sensitive to notch, which can reduce the impact strength by as much as 90%.

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