Acetal Polyoxymethylene Copolymer - POM UV Stabilised

Polyoxymethylene is made in both homopolymer and copolymer forms, which are not very different from each other. Both are tough, hard, stiff polymers with good appearance (can give high surface gloss) and excellent abrasion resistance.

Usually highly crystalline and opaque, their natural colour is white but they are typically used colored. They have poor resistance to UV and generally to alkalis and acids.

When compared to the copolymer, the homopolymer has slightly better mechanical properties but somewhat worse thermo-oxidative stability. Only the copolymer is suited for continuous use with hot water.

Polymer Type

Thermoplastic

Advantages

Superior UV resistance compared with unmodified grades. Titanium dioxide used for non-black UV resistant mouldings. Excellent mechanical properties and solvent resistance as expected with Acetal copolymer.

Disadvantages

In the case of carbon black modification best results are obtained with 1.5% of well-dispersed fine particles. However the finer the particle, the poorer the heat stability. Also prone to high mould shrinkage and attack by acids and bases as with unmodified copolymers.

Applications

Applications are wide-ranging including sporting equipment, for example ski boot bindings tennis racquet handles, most supports and frame connectors for windsurfing boards, toys, and also snap fittings, gears, bearings, and many other engineering components.

Acetal Polyoxymethylene Copolymer is used in sporting equipment such as windsurfing boards. Image Credit: ShutterStock/COLOMBONICOLA

Acetal Polyoxymethylene Copolymer is used in sporting equipment such as windsurfing boards. Image Credit: ShutterStock/COLOMBONICOLA

Typical Properties

Property Value
Density (g/cm3) 1.41
Surface Hardness RR117
Tensile Strength (MPa) 68
Flexural Modulus (GPa) 2.5
Notched Izod (kJ/m) 0.069
Linear Expansion (/°C x 10-5) 11
Elongation at Break (%) 60
Strain at Yield (%) 8
Max. Operating Temp. (°C) 90
Water Absorption (%) 0.22
Oxygen Index (%) 15
Flammability UL94 HB
Volume Resistivity (log ohm.cm) 14
Dielectric Strength (MV/m) 19
Dissipation Factor 1 kHz 0.0018
Dielectric Constant 1 kHz 3.8
HDT @ 0.45 MPa (°C) 155
HDT @ 1.80 MPa (°C) 105
Material. Drying hrs @ (°C) 2 @ 90
Melting Temp. Range (°C) 190 - 210
Mould Shrinkage (%) 1.8
Mould Temp. Range (°C) 60 - 120

Source : Abstracted from Plascams

For more information on Plascams please visit RAPRA Technology Ltd.

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