Polyoxymethylene (POM): Properties, Production, and Key Industry Applications

Polyoxymethylene (POM) is a high‑performance thermoplastic also known as acetal. Its chemical backbone features a carbon atom bonded to two –OR groups, giving it unique mechanical and thermal characteristics.

First identified by German chemist Hermann Staudinger in the 1920s, POM was later commercialized after DuPont’s breakthrough in 1960, producing the renowned Delrin® homopolymer. Celanese followed in 1962 with the Celcon® copolymer, and several other manufacturers now offer their own branded variants.

Key Properties

• Exceptional stiffness and hardness
• Low coefficient of friction and high abrasion resistance
• Excellent heat resistance and dimensional stability
• Low water absorption and good dielectric performance
• High gloss surface and highly crystalline structure
• Superior creep resistance compared to nylon
• Low smoke emissions

Limitations

• Flammable liquid; no flame‑retardant grade available
• Poor resistance to strong acids and alkalis
• High shrinkage during processing
• Limited temperature range for certain applications

Manufacturing Processes

Homopolymers are produced by anionic polymerization of anhydrous formaldehyde, followed by acetic anhydride stabilization and rigorous moisture removal. Copolymers require conversion of formaldehyde to trioxane via acid catalysis, then purification by distillation or extraction. These processes yield the distinct mechanical profiles of Delrin® and Celcon®.

Forming Techniques

POM is typically supplied as granules that can be molded under heat and pressure. Common fabrication methods include injection molding, rotational molding, blow molding, and extrusion into bars for machining. Due to its solvent resistance, thermal welding is the preferred bonding method for both homopolymer and copolymer grades.

Applications

POM’s precision and strength make it ideal for gear components, fasteners, and high‑performance parts. Other uses span from ski bindings and electronic cigarettes to watch bracelets, zippers, insulin pens, and metered‑dose inhalers. The material is also found in musical instrument components, food‑grade pumps, and synthetic flavoring agents.

For tailored material selection, contact Craftech.

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