Commonly used plastics and characteristics--POM

author: YITECH

2024-10-21

POM acetal copolymer is a strong and durable thermoplastic material with excellent resistance to wear, chemicals, and impact. Its low friction properties make it ideal for use in gears, bearings, and other mechanical and industrial applications.

POM(Polyoxymethylene)

1. POM performance

POM is a crystalline plastic, its steel is very good, commonly known as "game steel". POM is a tough and elastic material, even at low temperatures still has good creep resistance, geometric stability and impact resistance, it has fatigue resistance, creep resistance, wear resistance, heat resistance and other excellent properties.

POM is not easy to absorb moisture, the specific gravity is 1.42g/cm3, shrinkage rate of 2.1% (POM's high degree of crystallization leads to it has a very high shrinkage rate, which can reach 2%~3.5%, large, for a variety of different enhanced materials have different shrinkage rates), the size is difficult to control, and the thermal deformation temperature is 172℃. POM has both homopolymer and copolymer materials.

Homopolymer material has good tensile strength and fatigue resistance, but it is not easy to process. Copolymer materials have good thermal stability, chemical stability and easy processing. Both homopolymer and copolymer materials are crystalline and do not easily absorb water.

2.POM process characteristics

POM processing can not be dried before, it is best to preheat during processing (about 100 ° C), which is good for the stability of product size. The processing temperature range of POM is very narrow (195-215 ° C), and the residence time in the barrel is slightly longer or the temperature exceeds 220 ° C will decompose (homopolymer material is 190~230 ° C; Copolymer material is 190~210℃). Screw speed can not be too high, the residual amount should be less.

POM product shrinkage is large (in order to reduce the shrinkage rate after forming can choose a higher mold temperature), easy to produce shrinkage or deformation. POM specific heat is large, mold temperature is high (80-105℃), the product is very hot after stripping, need to prevent burning fingers. Injection pressure 700~1200bar, POM should be formed under the conditions of medium pressure, medium speed and high die temperature.

Runner and gate Any type of gate can be used. If a tunnel gate is used, it is best to use a shorter type. For homopolymer materials, a hot nozzle runner is recommended. For copolymer materials, both internal and external hot runways can be used.

3. Typical application range:

POM has a very low coefficient of friction and good geometric stability, especially suitable for the production of gears and bearings. Because it also has high temperature resistance, it is also used in pipeline devices (pipeline valves, pump housings), lawn equipment, etc.

Our company can provide POM material products, but also can provide powder injection molding customized services, if you have a demand for this can contact us to get a good quote!

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