POM-C Rod (copolyoxymethylene rod) is a high-performance thermoplastic engineering plastic rod based on copolyoxymethylene resin, which is formed by precision extrusion process. Copolyoxymethylene is a polymer material synthesized by copolymerization of formaldehyde monomer and a small amount of comonomer (such as ethylene oxide). The introduction of flexible copolymer units in its molecular chain not only retains the rigid characteristics of the formaldehyde segment, but also improves thermal stability and processing fluidity. Compared with homopolyoxymethylene (POM-H), POM-C has a slightly lower crystallinity (about 65%-75%), but its hot water resistance, chemical corrosion resistance and impact resistance are significantly improved. It is especially suitable for long-term use in high-temperature water environment or contact with chemical media. POM-C rods have extremely high surface finish, dimensional accuracy is controlled within ±0.05mm, diameter range covers 8mm to 500mm, and length can be customized. It is suitable for the manufacture of precision parts that require high dimensional stability, low friction coefficient and chemical corrosion resistance.
Product performance
Mechanical properties:
High rigidity and impact resistance: tensile strength 55-75MPa, bending modulus 2400-3200MPa, slightly lower than homopolyoxymethylene, but still significantly better than PA6 and PBT; cantilever beam notch impact strength ≥6kJ/m² (normal temperature), can still maintain good toughness at low temperature of -40℃, not easy to crack, suitable for high and low temperature alternating environment.
Low friction and high wear resistance: The friction coefficient is as low as 0.2-0.3, the wear resistance is 2-3 times that of PA6, and the surface wear rate is <0.05mm³/(N·m) after long-term use, which is suitable for high-frequency friction parts.
Thermal properties:
High temperature resistance and dimensional stability: Melting point is about 165-175℃, heat deformation temperature (under 1.82MPa load) is about 110-125℃, long-term use temperature range is -40℃ to 100℃ (can withstand 140℃ in a short term); linear expansion coefficient is only 8-10×10⁻⁵/℃, and the deformation under temperature fluctuation environment is only 1/5 of that of metal, suitable for precision instrument parts.
Excellent hot water resistance: After soaking in boiling water (100℃) for 1000 hours, the strength retention rate is >90%, which is much better than POM-H (strength attenuation is about 30%), suitable for hot water delivery pumps, steam valves and other parts.
Chemical properties:
Strong chemical corrosion resistance: Stable to most acids, alkalis, salt solutions and organic solvents, no expansion or deformation after long-term immersion; only sensitive to strong oxidants and high-temperature halogenated hydrocarbons, suitable for chemical storage tanks, laboratory utensils and other applications.
Outstanding hydrolysis resistance: The water absorption rate in a humid environment is only 0.2%-0.3%, and the dimensional change rate after water absorption is <0.1%, which is much lower than PA6 (water absorption rate 3%-4%), and is suitable for precision parts in high humidity environments.
Electrical properties:
Insulation and arc resistance: Volume resistivity ≥10¹⁴Ω·cm, dielectric strength 18-25kV/mm, and dielectric constant stable at 3.0-3.2 at high frequency (1MHz), suitable for low-voltage electrical insulation parts.
Processing performance:
Easy cutting and high precision: Micron-level tolerance control (such as ±0.01mm) can be achieved through turning, drilling, milling and other processes, and the surface roughness Ra≤0.4μm; low water absorption, no long-term annealing treatment is required after processing, and dimensional stability is better than PA6 and POM-H.
High molding efficiency: The extrusion speed is 15%-20% faster than POM-H, which is suitable for batch production of long-size bars, reducing the number of joints and improving component consistency.
Product Advantages
- Balanced comprehensive performance: It has high rigidity, low friction, chemical corrosion resistance and hot water resistance. It can meet the needs of complex working conditions without additional lubrication or surface treatment, reducing maintenance costs.
- Long-term stability: The performance degradation is minimal in high-temperature water environment or chemical medium for long-term use. It is suitable for replacing metals (such as brass and stainless steel) to manufacture precision parts and extend the life of equipment.
- High precision and economy: The dimensional stability is better than PA6 and POM-H, and the processing tolerance can reach IT6 level, reducing the subsequent finishing steps.
- Environmental protection and safety: It is non-toxic and complies with FDA and EU 10/2011 food contact safety standards. It can be used in food processing equipment or medical devices; it releases non-toxic gases when burned and complies with UL94 HB flame retardant grade.
Scope of application
The core value of POM-C Rod lies in its comprehensive characteristics of "chemical resistance, high temperature resistance and self-lubrication". It is suitable for fields that require high precision, corrosion resistance or wear resistance, especially in the automotive, machinery manufacturing, electronic and electrical and medical equipment industries. Its typical application scenarios include:
- Automobile manufacturing: engine peripheral parts, gears, bearings, etc.
- Machinery and industrial equipment: wear-resistant linings, guide rails, fasteners, etc.
- Electronic and electrical: insulating structural parts, connector housings, etc.
- Medical equipment: precision transmission parts, surgical tools, etc.
