POM CNC manufacturing Delrin®POM CNC machining

POM engineering plastics (polyoxymethylene) is a highly crystalline thermoplastic polymer, one of the synthetic resins, also known as polyoxymethylene resins, POM plastics, race steel material, etc.; it is a white or black plastic particles, with high hardness, high steel, high wear-resistant properties. Has excellent physical, mechanical and chemical properties, especially its friction resistance is particularly outstanding.POM is divided into two types of homo- and co-polyformaldehyde, of which homo-formaldehyde has a high density, crystallinity, melting point, but poor thermal stability, processing temperature range is narrower; and co-polyformaldehyde density, crystallinity, melting point is lower, but good thermal stability, not easy to decompose, processing temperature range is wider.

 

POM material has high mechanical strength and rigidity, good environmental resistance, resistance to organic solvents, good electrical properties and recovery, as well as self-lubricating and wear-resistant good dimensional stability. It is known as “race steel”, is the third largest general engineering plastics, mainly used in the manufacture of wear parts, transmission parts, and chemical, instrumentation and other parts.

 

With its high strength, high rigidity, low coefficient of friction, good chemical resistance and electrical properties, POM engineering plastics have become the preferred material for the manufacture of high-performance engineering components, especially in the need for wear-resistant, fatigue-resistant, dimensional stability of the scenario is outstanding.

 

Precision machining of POM (polyoxymethylene) stock involves a series of process steps including, but not limited to, cutting, grinding, drilling, tapping, milling, and CNC (computer numerical control) machining.

 

 

1. Material preparation: Drying treatment: Although POM has low water absorption, it is still necessary to check whether drying treatment is required before machining to avoid moisture causing material expansion or contraction during machining, which may affect dimensional accuracy. Usually, if the material has been stored in a humid environment for too long, it is recommended to dry it at 80°C for about 2 hours.

 

2. CNC machining:Cutting parameters:Cutting of POM usually requires the selection of appropriate cutting speed, feed rate and back draft. High-speed steel or carbide tools are common choices, cutting speed of about 100-250m/min, feed rate depends on the size of the tool and machining accuracy requirements. Coolant Lubrication: Machining may require the use of coolant to minimize tool wear and improve machined surface quality. For POM, water-soluble emulsified oil is usually a suitable coolant.

 

3. Finishing: Surface finish: In order to obtain high accuracy and good surface finish, secondary processing, such as grinding, polishing, etc., may be required. Dimensional tolerances: precision machining, dimensional tolerance control is critical, the processing of POM requires special attention to the impact of temperature changes on the size of the material.

 

4. Post-processing Cleaning:The processed parts need to be cleaned to remove chips, cutting oils and other impurities to prevent corrosion or affect the subsequent assembly.

 

5. Precautions:Thermal stability: POM is easy to decompose at high temperatures, so the processing temperature should be controlled within a reasonable range to avoid material degradation. Safety measures:Dust generated during processing may be flammable, appropriate safety measures are required.