Polyoxymethylene is manufactured in both homopolymer and copolymer forms which are somewhat similar to each other. Both forms are hard, tough, and stiff polymers with good appearance (has a highly glossy surface) and excellent abrasion resistance.
They are generally opaque and highly crystalline. Although their natural color is white, they are often used colored. They show poor resistance to UV and generally to acids and alkalis.
When compared to the copolymer. The mechanical properties of the homopolymer is slightly better but its thermo-oxidative stability is somewhat worse. Only the copolymer is suitable for continuous use with hot water.
Polymer Type
Thermoplastic
Advantages
Advantages of Acetal Polyoxymethylene Homopolymer include low coefficient of friction compared to unmodified grades, good solvent resistance, as with homopolymer, and good hydrolytic stability.
Disadvantages
Reduced mechanical properties i.e. stiffness, strength and toughness, compared to unmodified homopolymer, poor resistance to acids, bases and UV radiation are some of the disadvantages of Acetal Polyoxymethylene Homopolymer.
Applications
Applications include gears, bearings, snap fittings, bearing bushes, conveyor belt components, sprockets, switch components, pulley wheels, and many other engineering components, plumbing fittings, appliance casings and jug kettles.
Typical Properties
| Property |
Value |
| Density (g/cm3) |
1.54 |
| Surface Hardness |
RR118 |
| Tensile Strength (MPa) |
48 |
| Flexural Modulus (GPa) |
2.4 |
| Notched Izod (kJ/m) |
0.037 |
| Linear Expansion (/°C x 10-5) |
9 |
| Elongation at Break (%) |
12 |
| Strain at Yield (%) |
4 |
| Max. Operating Temp. (°C) |
90 |
| Water Absorption (%) |
0.2 |
| Oxygen Index (%) |
15 |
| Flammability UL94 |
HB |
| Volume Resistivity (log ohm.cm) |
16 |
| Dielectric Strength (MV/m) |
20 |
| Dissipation Factor 1 kHz |
0.009 |
| Dielectric Constant 1 kHz |
3.3 |
| HDT @ 0.45 MPa (°C) |
165 |
| HDT @ 1.80 MPa (°C) |
118 |
| Material. Drying hrs @ (°C) |
2 @ 90 |
| Melting Temp. Range (°C) |
210 - 230 |
| Mould Shrinkage (%) |
2.1 |
| Mould Temp. Range (°C) |
70 - 110 |
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This information has been sourced, reviewed and adapted from materials provided by Dotmar EPP Pty Ltd.
For more information on this source, please visit Dotmar EPP Pty Ltd.