POM (Polyoxymethylene)
Description

POM, commonly called acetal, is a highly crystalline thermoplastic polymer exhibiting excellent wear resistance in both wet and dry environments. Both homopolymers and copolymers versions are available for this engineering plastic. Because of higher crystallinity of homopolymer, it has slightly higher density, hardness, strength, and fatigue resistance. Copolymer has better thermal stability, chemical resistance, and ease of processing.

Features
  • Good Creep Resistance & High Dimensional Stability even at low temperatures.
  • High Strength, Rigidity and Toughness over a wide temperature range.
  • Resistant to Chemicals:Good resistance to organic solvents and synthetic detergents...
  • Good Resistance to Hydrolysis:Excellent hydrolysis resistance up to 140 °F
  • Good Electric Insulation
  • Low Water Absorption
Applications

gears, bearings, bushings, rollers, conveyors, window guides, sliding & spring elements, insulators, speaker grilles, fasteners, ski-bindings, zippers, lighters, fuel pump plates, aerosol valves, watch bracelets, medical devices, snap-fits, impellers, furniture components, coils…

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Technical Data
Item Property Test Method Unit POM-H POM-C
Physical Density ASTM D 792 g/cm3 1.41 1.14
Water Absorption ASTM D 570 % 0.16 0.22
Rockwell Hardness ASTM D 785 R scale 120 120
 
Mechanical Tensile Modulus ASTM D 638 psi 4.0 × 105 4.5 × 105
Tensile Strength ASTM D 638 psi 11,000 9,430
Flexural Modulus ASTM D 790 psi 4.5 × 105 3.9 × 105
Flexural Strength ASTM D 790 psi 13,000 12,000
Izod Impact ASTM D 256 ft-lb/in 1.0 1.0
 
Thermal Heat Deflection Temperature ASTM D 648 °C/°F 121 / 250 110 / 230
Linear Coefficient of Expansion ASTM D 696 in/in/°F 4.7 × 10-5 5.4 × 10-5
Flammability ASTM D 635 - HB HB
 
Electrical Electrical Volume Resistivity at 50% RH ASTM D 257 Ω/cm 1015 1015
Dielectric Constant ASTM D 150 1 MHz 3.7 3.8
Dissipation Factor ASTM D 150 1 MHz 0.005 0.005
Dielectric Strength ASTM D 149 V/mm 33,000 40,000