POM
Polyacetal or polyoxymethylene (POM)
Is a thermoplastic polymer with a low friction coefficient, good dimensional stability, high abrasion and temperature resistance, and low moisture absorption.
top applications
Mechanical Gears
Bearings
Lawn Equipment
Electrical Parts
Valve & Pump Housings
Vehicle Interiors & Lock Systems
product spec sheets
| Product | Classification | Features | Uses | |
|---|---|---|---|---|
| ProductFORMOCON® FM090 | ClassificationAcetal (POM) Copolymer | FeaturesGood Flow | UsesAutomotive Applications; Bearings; Buttons; | Download |
| ProductFORMOCON® FM270 | ClassificationAcetal (POM) Copolymer | FeaturesHigh Flow | UsesElectrical/Electronic Applications; Fasteners | Download |
| ProductFORMOCON® FM025 | ClassificationAcetal (POM) Copolymer | FeaturesHigh Viscosity | UsesRods; Sheet | Download |
| ProductFORMOCON® FM130 | ClassificationAcetal (POM) Copolymer | FeaturesMedium Flow | UsesButtons; Gears | Download |
| ProductFORMOCON® FM450 | ClassificationAcetal (POM) Copolymer | FeaturesHigh Flow | UsesElectrical/Electronic Applications; Fasteners; Gears | Download |
Why POM?
- Excellent Dimensional Stability
- High And Long-Term Mechanical Strength
- High Stiffness
- Good Wear and Abrasion Resistance
- Low Coefficient of Friction
- Low Moisture Absorption
- NSF KTW WRAS ACS W270 certified
- Resistance to Gasoline, Solvents & Other Neutral Chemicals
- Long term deployment under low/ high temperature and other harsh environment
- FDA/EC Food Contact Qualified
Application Factors and Limitations
- POM can not tolerate strong acidic (<pH4) or strong basic (>pH9) conditions long term.
- Very difficult to print on POM neither easy to bond to similar and dissimilar substrates
- Low surface energy & Non-polarisation
- Narrow processing window
- Less gloss surface
- Relatively higher specific gravity than general polymers
- Flammable
Conditions for Injection molding
Drying
Not usually required but the material should be stored in a dry atmosphere.
Runners & Gates
Any type of gate can be used. Circular tapered gates should be as short as possible. Insulated, hot tip runners are preferred for homopolymers. Both internally and externally heated hot runners can be used with copolymers.
Melt Temperature
180°C–230°C [356°F–446°F] for homopolymer 190°C–210°C [374°F–410°F] for copolymer
Mold Temperature
50°C–105°C [122°F–221°F]. Higher mold temperatures are preferred for precision molding to reduce post-molding shrinkage.
Material Injection Pressure
70–120 MPa
Injection Speed
Medium–high
Chemical & Physical Properties
Acetals like POM are tough, resilient materials that exhibit good creep resistance, dimensional stability, and impact resistance even at low temperatures.
Acetal grades are either homopolymers or copolymers. Homopolymers have better tensile strength, fatigue resistance and hardness, but are difficult to process. Copolymers have better thermal stability, chemical resistance, and processability. Both homopolymers and copolymers are crystalline and have low moisture absorption.
Copolymers can be used continuously at air temperatures up to 100°C [212°F]. Homopolymers have slightly higher temperature resistance. The many grades of acetal materials that are available can be tailored for different applications.