POM

Polyoxymetylene, Polyacetal

Overview

Applications

Comparison

Chemical formula

Specific gravity

1.41

Thermal properties

-50

Tg(℃)

180

Tm(℃)

Characteristics

Sliding property

Chemical resistance

Molding dimensional accuracy

Low water absorption

Weatherabilty

Flammable

Colorability

Commentary

It is called "POM" or "polyacetal". POM is an abbreviation for "Polyoxymetylene."
・Homopolymer: Addition polymerization using formaldehyde as a monomer. The upper limit of practical use is about 85°C.
・Copolymer: Ring-opening polymerization torioxane and small amount of ethylene oxide. The upper limit of practical use is about 105°C.

Key points

High crystallization, low water absorption, good molding dimensional accuracy, good wear resistance and sliding properties, so it is used for gears, bearings, etc.

Low oxygen index, one of the most flammable types of plastics, smells of formalin when burned

Gears

Reason for adoption

Hard, smooth, and excellent wear resistance (sliding properties), does not deform when humidified (low water absorption), does not chip (tough), can be shaped firmly (molding dimensional accuracy), resistant to oil (oil resistance)

Bearings

Reason for adoption

Fuel pump module

Reason for adoption

Lightweight (lighter than metal), does not leak gasoline (chemical resistance, dimensional accuracy, fuel permeability resistance)

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