Acetal Plastic Material Properties | Polyoxymethylene Copolymer POM Material Properties

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Polyoxymethylene (POM Acetal)
These polymers are highly crystalline thermoplastics that are commercially available as homopolymers or copolymers. This crystallinity is responsible for their excellent solvent resistance, fatigue resistance, surface finish and predictable mechanical properties over a wide temperature range. POMs are superior to PAs in stiffness, creep resistance, fatigue strength and water absorption, but have inferior impact and abrasion resistance. In general, the copolymers are thermally more stable, with similar mechanical properties to the homopolymer, with reduced tensile properties.

Acetal Polyoxymethylene Copolymer – POM

Polymer Type

Thermoplastic
Acetal is the common name for a family of thermoplastics with the chemical name "PolyOxy-Methylene". Acetal is available in a general purpose copolymer grade, a homopolymer version , and several filled grades. Acetal provides high strength and stiffness, enhanced dimensional stability, and is easy to machine. As a semi-crystalline material, acetal is characterized by a low coefficient of friction and good wear properties.

Advantages

Excellent rigidity, impact toughness, abrasion resistance, creep resistance and solvent resistance. Good appearance, hydrolytic stability fatigue endurance and low coefficient of friction. Better creep resistance, thermal stability, resistance to bases and processability than homopolymer. Higher continuous use temperature than homopolymer, about 100°C ( 212°F ) in air compared to 80°C ( 175°F ).

Disadvantages

High mould shrinkage (approximately 2%). Post moulding shrinkage of about 0.1% normally complete within 48hrs. Attacked by acids and bases, very rapid attack by nitric acid. Very poor resistance to UV radiation. Homopolymers have higher tensile strength, flexural strength, fatigue resistance and hardness. Cannot be fire retarded Explosive decomposition if processed with halogens.

GENERAL PROPERTIES

Acetal is the common name for a family of thermoplastics with the chemical name "PolyOxy-Methylene". Acetal is available in a general purpose copolymer grade, a homopolymer version , and several filled grades. Acetal provides high strength and stiffness, enhanced dimensional stability, and is easy to machine. As a semi-crystalline material, acetal is characterized by a low coefficient of friction and good wear properties.

FEATURES

• High strength, stiffness, dimensional stability
• Very low moisture absorption
• Good wear and abrasion resistance
• Wide range chemical resistance (including many solvents)

ACETAL GRADES

ACETAL COPOLYMER (unfilled)
The copolymer grade offers excellent performance at a slightly lower cost. Acetal copolymer may exhibit center line porosity, but porosity-free material is available. Certain grades are FDA, USDA, NSF, Canada AG and 3-A Dairy compliant. Low stress levels and high strength assure flatness and dimensional stability up to a maximum continuous service temperature of 180°F (80°C). Acetal copolymers are available in a wide variety of colors (see above photo), including BLACK , GREY , WHITE , BLUE , GREEN , YELLOW , ORANGE , RUST , RED & BROWN .

Typical Properties of ABS

Property	Value
Density (g/cm3)	1.41
Surface Hardness	RR117
Tensile Strength (MPa)	73
Flexural Modulus (GPa)	2.58
Notched Izod (kJ/m)	0.069
Linear Expansion (/°C x 10-5)	11
Elongation at Break (%)	65
Strain at Yield (%)	8
Max. Operating Temp. (°C)	90
Water Absorption (%)	0.22
Oxygen Index (%)	15
Flammability UL94	HB
Volume Resistivity (log ohm.cm)	15
Dielectric Strength (MV/m)	20
Dissipation Factor 1kHz	0.0015
Dielectric Constant 1kHz	3.7
HDT @ 0.45 MPa (°C)	160
HDT @ 1.80 MPa (°C)	110
Material. Drying hrs @ (°C)	3 @ 90
Melting Temp. Range (°C)	190 - 210
Mould Shrinkage (%)	1.8
Mould Temp. Range (°C)	60 - 120

NOTE: The information contained herein are typical values intended for reference and comparison purposes only. They should NOT be used as a basis for design specifications or quality control. Contact us for manufacturers' complete material property datasheets.
All values at 73°F (23°C) unless otherwise noted.