Polyoxymethylene (POM), commonly called acetal resin, is a semi-crystalline thermoplastic material with good mechanical strength and rigidity, good flow characteristics and excellent wear resistance, as well as low moisture absorption. The permeability to gases and vapors, also of organic substances, is low. Good dimensional stability and fatigue resistance, together with excellent machinability and low cost, make POM a highly versatile engineering material, even for complex components. However, within the acetal group, a distinction must be made between homopolymer POM (POM-H) and copolymer POM (POM-C), as they have different mechanical and thermal properties.
Both homopolymers and copolymers are attacked by strong acids (ph 4) and oxidizing agents, both are not soluble and hardly swell in all types of organic solvents, fuels and mineral oils. The stabilized types are resistant to diesel fuels and aggressive petrol up to a temperature of 100 ° C. The non-stabilized formulations are attacked by UV rays, therefore it is advisable to use those stabilized against UV rays or loaded with carbon black. The colored formulations are also available with stabilization.
Thin sheets of POM are transparent; they burn with a slightly bluish flame and drain. Physiologically they are harmless and some types are suitable for food products. To avoid post-shrinkage in products with high dimensional precision, subsequent thermal conditioning is carried out from 110 ° C to 140 ° C.
POM qualitative properties: excellent ductility and tenacity, good dimensional stability, low hygroscopicity, low water absorption (therefore good dimensional stability even in humid environments), good sliding properties and wear resistance, good workability on machine tools, good dielectric and insulation properties electrical, good chemical resistance (including many solvents), physiologically inert in contact with foodstuffs.
Applications:
- Automotive;
- Consumer goods;
- Security equipment;
- Builiding;
- Gears;
- Springs;
- Chains;
- Screws;
- Handles;
-
Zippers;
-
Clamps;
-
Fuel pumps;
-
Inhalers;
- Slides for furniture.
POM C is a copolymer acetal resin (i.e. polymer formed from a chain of monomers of different types) in which formaldehyde is converted to trioxane and this is polymerized together with a comonomer in the polyoxymethylene copolymer.
It has a better chemical resistance and a lower melting point than the homopolymer variant (from 162 ° C to 173 ° C).
Coloring : Full Compound or Dry Blend (SPL) according to the type.
POM-H is a homopolymer acetal resin (i.e. a polymer formed by a chain of identical monomers): this guarantees a high level of crystallinity, a slightly higher density than POM C, and consequently a major hardness and mechanical resistance. The melting point is 175 ° C.
Unreinforced homopolymers are the most rigid and resistant thermoplastic materials and have excellent dimensional stability, so much so that they weaken at temperatures below -40 ° C.
Coloring : Full Compound or Dry Blend (SPL) according to the type.
Natural or Compound types of colored POM FV or SV (RAL, Pantone or sample references) with different grades of glass fiber or glass beads reinforcements for injection molding of parts requiring a greater rigidity.
Coloring : Full Compound or Dry Blend (SPL) according to the type.
Natural or Compound types of colored POM CM (RAL, Pantone or sample references) with mineral filler .
Coloring : Full Compound or Dry Blend (SPL) according to the type.
Natural or Compound types of colored POM EM (RAL, Pantone or sample references) with different grades of elastomer .
Coloring : Full Compound or Dry Blend (SPL) according to the type.
Natural or Compound types of colored POM (RAL, Pantone or sample references)
Available in various versions:
- LUB: PTFE or molybdenum disulphide lubricated;
- Different fillers: aramidic fiber;
- FST: improved moldability;
- LO: Low Emission (for automotive);
- IQ: industrial quality grades;
or, if possible, with a combination of the above characteristics.
Coloring : Full Compound or Dry Blend (SPL) according to the type.
TECHNICAL CHART
The chart shows the various types of products we are present on the market with:
POM chemical formula: (CH2O)n
POM chemical name (IUPAC): poly(oxymethylene)
CAS Number : 9002-81-7
POM recycling code: Number 7
Custom tariff: 39071090
