When selecting acetal plastic for industrial use, it’s important to understand the difference between POM-C (copolymer acetal) and POM-H (homopolymer acetal). Though both materials fall under the acetal or polyoxymethylene (POM) family, they differ in molecular structure, performance characteristics, and processing behavior.
POM-C, or copolymer acetal, is known for its enhanced chemical resistance and lower porosity, making it suitable for applications involving moisture or aggressive cleaning agents. On the other hand, POM-H, also called homopolymer acetal, often recognized under the brand Delrin®, offers slightly better mechanical strength and stiffness, ideal for precision parts requiring high dimensional stability.
Understanding the key differences between copolymer vs homopolymer acetal will help you choose the right material for gears, bushings, bearings, and other high-performance plastic components.
| Property | POM-C (Copolymer Acetal) | POM-H (Homopolymer Acetal / Delrin®) |
|---|---|---|
| Chemical Structure | Copolymerized with multiple monomers for improved stability | Made from a single monomer (formaldehyde) |
| Brand Examples | Acetal Copolymer, CELCON®, Ultraform® | Delrin®, Kepital-H |
| Mechanical Strength | ⭐⭐⭐⭐ Slightly lower than POM-H | ⭐⭐⭐⭐⭐ Higher tensile and flexural strength |
| Stiffness & Rigidity | ⭐⭐⭐⭐ Good | ⭐⭐⭐⭐⭐ Excellent |
| Dimensional Stability | ⭐⭐⭐⭐ Stable, less sensitive to stress cracking | ⭐⭐⭐⭐⭐ Very stable and precise |
| Wear Resistance | ⭐⭐⭐⭐ Good | ⭐⭐⭐⭐ Excellent, slightly better than POM-C |
| Moisture Resistance | ⭐⭐⭐⭐⭐ Excellent – low porosity, better in wet environments | ⭐⭐⭐ Medium – slightly more moisture absorption |
| Résistance chimique | ⭐⭐⭐⭐⭐ Superior – resists acids, bases, fuels | ⭐⭐⭐⭐ Good, but more sensitive to hydrolysis |
| Friction & Sliding Behavior | ⭐⭐⭐⭐ Low friction, good sliding properties | ⭐⭐⭐⭐⭐ Ultra-low friction, better for dry-running parts |
| Machinability | ⭐⭐⭐⭐ Easy to cut, drill, mill | ⭐⭐⭐⭐⭐ Excellent surface finish, more rigid during machining |
| Porosity | Low – better for fluid-tight applications | Higher – may absorb more moisture over time |
| Thermal Stability | ⭐⭐⭐ Stable up to ~100–110°C | ⭐⭐⭐⭐ Slightly higher stability, up to ~120°C |
| Price | 💲💲 Affordable, widely used | 💲💲💲 Slightly more expensive due to Delrin® brand premium |
| Best Applications | Food processing, pump housings, fluid-handling parts | Precision gears, tight-tolerance bushings, electrical insulators |
Understanding the technical and performance differences between POM-C (copolymer) and POM-H (homopolymer) is essential when choosing the right material for engineering applications. Each grade has its strengths—POM-C offers better chemical resistance and dimensional stability, while POM-H provides higher stiffness and better wear performance under dry conditions. The right choice depends on your specific working environment, design requirements, and machining needs.
At Plastique Tengyi, we supply both POM-C and POM-H sheets and rods, helping customers around the world find the most suitable solution for their industrial needs. If you’re unsure which grade is right for your application, our team is ready to offer technical support and professional guidance.
Contact us today to learn more about our POM materials and how we can support your project with quality products from China.
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