What Is Polyoxymethylene (POM) and Its Key Applications

Polyoxymethylene (POM), also known as acetal or polyacetal, is a high-performance engineering thermoplastic known for its excellent mechanical strength, dimensional stability, and wear resistance. It is widely used in precision parts and industrial applications where high stiffness, low friction, and durability are required.

Composition and Properties

• Base Material: Polyoxymethylene (homopolymer or copolymer)

• Additives: Stabilizers, lubricants, and anti-oxidants depending on application

• Processing Methods: Injection molding, extrusion, and machining

POM exhibits high tensile and flexural strength, low moisture absorption, and good chemical resistance, making it ideal for precision mechanical components.

Key Features

• High Mechanical Strength: Excellent tensile and flexural properties

• Dimensional Stability: Maintains shape under load and temperature changes

• Low Friction & Wear Resistance: Ideal for moving parts and gears

• Chemical Resistance: Resistant to fuels, solvents, and lubricants

• Good Fatigue Resistance: Long service life in repetitive mechanical applications

• Ease of Machining: Can be machined to tight tolerances

Applications

• Automotive: Gears, bushings, clips, and fuel system components

• Industrial Machinery: Bearings, conveyor rollers, and precision components

• Electrical & Electronics: Connectors, switches, and housings

• Consumer Goods: Zippers, mechanical parts, and small durable components

• Medical Devices: Durable components requiring low friction and biocompatibility

Advantages

• High stiffness and strength for load-bearing applications

• Excellent wear resistance, reducing maintenance requirements

• Low moisture absorption ensures dimensional stability

• Smooth surface finish suitable for precision mechanical parts

• Cost-effective compared to metal for lightweight components

Limitations

• Sensitive to strong acids and oxidizing agents

• Thermal stability is lower than some engineering plastics like PEEK

• Not suitable for high-temperature continuous exposure (>100–120°C for standard POM)

Technical Parameters (Typical)

• Density: 1.41–1.42 g/cm³

• Tensile Strength: 60–70 MPa

• Flexural Strength: 80–100 MPa

• Impact Strength (Notched Izod): 20–30 kJ/m²

• Melting Temperature: 165–175°C

• Moisture Absorption: <0.2%

• Processing Methods: Injection molding, extrusion, CNC machining

FAQs

Q1: Why is POM widely used for gears and mechanical components?
Because it combines high strength, low friction, and excellent wear resistance, ideal for moving parts.

Q2: Can POM be used outdoors?
It can be used outdoors with UV stabilizers, but standard POM is sensitive to prolonged sunlight exposure.

Q3: How does POM compare with Nylon (PA)?
POM has higher stiffness, lower moisture absorption, and better dimensional stability, while PA is tougher and more flexible under impact.

Q4: Is POM machinable?
Yes, it can be machined to precise tolerances, making it suitable for precision components.