Overview
POM-C (Polyoxymethylene Copolymer), commonly known as Acetal Copolymer, is a high-performance engineering thermoplastic recognized for its exceptional dimensional stability, low friction, wear resistance, chemical resistance, and machinability.
Compared with POM-H (Acetal Homopolymer / Delrin®), POM-C offers superior chemical resistance, improved hydrolysis resistance, lower centerline porosity, and better dimensional consistency. These characteristics make POM-C the preferred choice for precision-machined components and industrial applications requiring high reliability.
POM-C is widely used in:
- Precision Gears
- Bearings and Bushings
- Conveyor Components
- Food Processing Equipment
- Medical Device Components
- Pumps and Valves
- Electrical Insulators
- Industrial Machinery Parts
Due to its excellent combination of mechanical performance and dimensional stability, POM-C is one of the most widely used engineering plastics for precision manufacturing.
Material Specification
| Property | Value |
|---|---|
| Material Designation | POM-C |
| Full Name | Polyoxymethylene Copolymer |
| Common Name | Acetal Copolymer |
| Material Family | Engineering Thermoplastic |
| Density | 1.40–1.42 g/cm³ |
| Appearance | Natural (White), Black, Blue |
| Typical Manufacturing Methods | CNC Machining, Injection Molding, Extrusion |
| Standard Forms | Rod, Sheet, Tube, Pellets |
Chemical Composition
POM-C is a copolymerized polyacetal material containing modified formaldehyde chains that improve chemical and thermal stability.
| Component | Function |
|---|---|
| Polyoxymethylene Copolymer | Structural Matrix |
| Stabilizers | Thermal Stability |
| Lubricants (Optional) | Friction Reduction |
| Reinforcements (Optional) | Enhanced Strength |
Common variants include:
- Food Grade POM-C
- ESD POM-C
- Glass Filled POM-C
- PTFE Filled POM-C
- FDA-Compliant POM-C
Mechanical Properties
Typical Values
| Property | Value |
|---|---|
| Tensile Strength | 60–70 MPa |
| Yield Strength | 55–65 MPa |
| Elongation at Break | 20–40% |
| Flexural Strength | 80–100 MPa |
| Flexural Modulus | 2.5–3.2 GPa |
| Hardness | Rockwell M85–95 |
| Compressive Strength | 90–120 MPa |
Typical Mechanical Performance
| Property | Performance |
|---|---|
| Stiffness | Excellent |
| Wear Resistance | Excellent |
| Fatigue Resistance | Excellent |
| Creep Resistance | Excellent |
POM-C provides excellent mechanical performance with superior dimensional consistency.
Physical Properties
| Property | Value |
|---|---|
| Density | 1.40–1.42 g/cm³ |
| Water Absorption (24h) | 0.15–0.30% |
| Saturated Water Absorption | 0.6–0.8% |
| Thermal Conductivity | 0.30–0.35 W/m·K |
| Electrical Resistivity | >10¹⁴ Ω·cm |
| Specific Heat Capacity | 1500 J/kg·K |
POM-C exhibits extremely low moisture absorption, making it ideal for precision applications.
Thermal Properties
| Property | Value |
|---|---|
| Melting Point | 160–170°C |
| Glass Transition Temperature | -60°C |
| Heat Deflection Temperature | 100–115°C |
| Continuous Service Temperature | -40°C to 100°C |
| Short-Term Service Temperature | Up to 140°C |
POM-C maintains stable performance across a wide temperature range.
Strength-to-Weight Ratio
| Material | Density (g/cm³) | Tensile Strength |
|---|---|---|
| POM-C | 1.41 | 65 MPa |
| POM-H | 1.42 | 75 MPa |
| PA66 | 1.14 | 90 MPa |
| Aluminum 6061 | 2.70 | 310 MPa |
POM-C offers excellent structural performance while maintaining lightweight characteristics.
Wear Resistance
| Property | Performance |
|---|---|
| Abrasion Resistance | Excellent |
| Sliding Wear Resistance | Excellent |
| Surface Durability | Excellent |
| Bearing Performance | Outstanding |
POM-C is widely used for gears, bushings, and low-friction moving assemblies.
Friction Properties
| Property | Value |
|---|---|
| Coefficient of Friction | 0.20–0.35 |
| Self-Lubricating | Yes |
| Dry Running Capability | Excellent |
| Noise Reduction | Excellent |
The naturally low friction coefficient reduces maintenance requirements and improves service life.
Dimensional Stability
| Property | Performance |
|---|---|
| Moisture Resistance | Outstanding |
| Thermal Stability | Excellent |
| Shrinkage Control | Excellent |
| Precision Machining Capability | Outstanding |
POM-C is often preferred over Nylon when tight tolerances are required.
Chemical Resistance
| Chemical Environment | Performance |
|---|---|
| Oils & Greases | Excellent |
| Fuels | Excellent |
| Alcohols | Excellent |
| Solvents | Good |
| Hydrocarbons | Excellent |
| Weak Alkalis | Excellent |
| Hot Water | Excellent |
| Strong Acids | Poor |
Compared with POM-H, POM-C offers superior chemical and hydrolysis resistance.
Food and Medical Compatibility
| Property | Performance |
|---|---|
| FDA Compliance Grades | Available |
| EU Food Contact Grades | Available |
| Medical Grades | Available |
| Moisture Resistance | Excellent |
POM-C is commonly used in food processing and medical equipment components.
Electrical Properties
| Property | Value |
|---|---|
| Volume Resistivity | >10¹⁴ Ω·cm |
| Surface Resistivity | >10¹³ Ω |
| Dielectric Strength | 18–25 kV/mm |
| Dielectric Constant | 3.7–4.0 |
POM-C is suitable for electrical and electronic precision components.
Machinability
| Process | Rating |
|---|---|
| CNC Milling | Outstanding |
| CNC Turning | Outstanding |
| Drilling | Outstanding |
| Tapping | Outstanding |
| Routing | Excellent |
Machinability Comparison
| Material | Machinability |
|---|---|
| POM-C | Outstanding |
| POM-H | Excellent |
| Nylon | Excellent |
| Polycarbonate | Good |
POM-C is considered one of the best engineering plastics for CNC machining.
Injection Molding Characteristics
| Property | Rating |
|---|---|
| Moldability | Excellent |
| Flow Characteristics | Excellent |
| Surface Finish | Excellent |
| Dimensional Accuracy | Outstanding |
| Production Efficiency | Excellent |
POM-C is widely used in precision injection molding applications.
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| ISO | POM-C |
| ASTM | Acetal Copolymer |
| DIN | POM-C |
| JIS | Polyacetal Copolymer |
| GB/T (China) | 共聚甲醛（POM-C） |
| FDA | Food Grade POM-C |
Available Forms
| Product Type | Availability |
|---|---|
| Rod | Yes |
| Sheet | Yes |
| Tube | Yes |
| Pellets | Yes |
| Injection Molded Parts | Yes |
| Machined Components | Yes |
Typical Applications
Industrial Machinery
- Precision Gears
- Bearings
- Bushings
- Rollers
- Wear Pads
Food Processing Equipment
- Conveyor Components
- Filling Equipment Parts
- Food Contact Components
Medical Industry
- Device Components
- Instrument Mechanisms
- Precision Assemblies
Automotive Industry
- Fuel System Components
- Door Mechanisms
- Gear Assemblies
- Interior Mechanisms
Electrical Industry
- Connectors
- Switch Components
- Insulators
- Precision Electrical Parts
Packaging Industry
- Guide Rails
- Conveyor Systems
- Wear Strips
Manufacturing Characteristics
| Manufacturing Process | Rating |
|---|---|
| CNC Machining | Outstanding |
| Injection Molding | Outstanding |
| Extrusion | Excellent |
| Secondary Assembly | Excellent |
Advantages
Outstanding Dimensional Stability
Maintains tight tolerances in humid environments.
Excellent Wear Resistance
Ideal for moving and sliding components.
Low Friction
Provides self-lubricating performance.
Superior Chemical Resistance
Better chemical resistance than POM-H.
Excellent Machinability
Highly suitable for precision CNC manufacturing.
Food and Medical Compatibility
Available in FDA and medical-grade formulations.
Limitations
Lower Strength Than POM-H
Slightly lower tensile strength than homopolymer grades.
Limited UV Resistance
Outdoor use may require UV-stabilized grades.
Acid Sensitivity
Strong acids can degrade the material.
Moderate Heat Resistance
Not suitable for extreme high-temperature environments.
Comparison with Common Engineering Plastics
| Property | POM-C | POM-H | PA66 | PEEK |
|---|---|---|---|---|
| Dimensional Stability | Outstanding | Excellent | Good | Outstanding |
| Wear Resistance | Excellent | Excellent | Excellent | Outstanding |
| Moisture Resistance | Outstanding | Excellent | Moderate | Outstanding |
| Machinability | Outstanding | Excellent | Excellent | Good |
| Chemical Resistance | Better | Good | Good | Excellent |
Comparison with POM-H (Delrin®)
| Property | POM-C | POM-H |
|---|---|---|
| Chemical Resistance | Better | Good |
| Hydrolysis Resistance | Better | Moderate |
| Centerline Porosity | Lower | Higher |
| Dimensional Stability | Better | Excellent |
| Tensile Strength | Slightly Lower | Higher |
Available Surface Finishes
Standard Finishes
- Natural Finish
- Black Finish
- Blue Food-Grade Finish
Functional Finishes
- CNC Machined Finish
- Precision Ground Finish
- Polished Finish
Specialty Grades
- FDA Grade POM-C
- ESD POM-C
- PTFE Filled POM-C
- Glass Filled POM-C
Frequently Asked Questions (FAQ)
What is POM-C?
POM-C is an acetal copolymer engineering plastic known for excellent dimensional stability, wear resistance, and chemical resistance.
What is POM-C used for?
Typical applications include:
- Gears
- Bearings
- Bushings
- Food Processing Equipment
- Precision Mechanical Components
What is the difference between POM-C and Delrin®?
Delrin® is a POM-H (homopolymer) material. POM-C offers better chemical resistance, lower porosity, and improved dimensional consistency.
Is POM-C food safe?
Yes. FDA-compliant grades are available for food contact applications.
Can POM-C be machined?
Yes. POM-C is one of the best engineering plastics for CNC machining.
Why choose POM-C?
Because it combines:
- Excellent Dimensional Stability
- Outstanding Machinability
- Low Friction
- Superior Chemical Resistance
- Long Service Life
Is POM-C better than Nylon?
For precision parts requiring moisture resistance and tight tolerances, POM-C is often preferred.
Does GCNOV provide POM-C manufacturing services?
Yes. GCNOV provides:
- POM-C CNC Machining
- POM-C Injection Molding
- FDA-Grade Component Manufacturing
- Custom Plastic Fabrication
- Prototype Development
- Low-Volume Production
- Mass Production
- Precision Mechanical Parts Manufacturing