Polyoxymethylene (POM), also known as aldehyde polymer, polyoxymethylene and polyacetaldehyde, is an engineering thermoplastic. Its density is between 1.410-1.420 g/cm³. It not only has excellent hardness, strength and rigidity, but also has chemical resistance, dimensional stability, mechanical strength and low friction coefficient, making it a reliable material in engineering applications.

Although POM has excellent mechanical properties and wear resistance, it still faces some problems during processing, which are summarized as follows:

1. Cracking problem

POM materials are prone to cracking during processing, especially during high-speed CNC processing or deep cutting. This is caused by the release of internal stress or uneven cooling of the material. In order to reduce the occurrence of cracking, reasonable cooling and processing parameters are essential. During processing, it is necessary to ensure uniform cooling speed and avoid sharp temperature changes. Using appropriate cutting fluid and adjusting cutting speed can also help reduce the risk of material cracking.

2. Deformation problem

POM plastic has high hygroscopicity, so changes in humidity and temperature during processing may cause it to deform. POM material expands when the temperature rises and may shrink after cooling, especially when processing larger parts or complex shapes. In addition, if the cutting force is too large during the processing of POM, it may cause deformation, especially when processing thin walls or micro structures.

3. Tool wear

POM has a low hardness. Although it generates relatively little heat during processing, its sticky properties may cause rapid tool wear. The material and coating selection of the tool, as well as reasonable cutting conditions, can effectively extend the service life of the tool. Using high-quality carbide tools or coated tools, combined with precise cutting parameters, can help reduce tool wear and improve processing quality.

4. Surface quality issues

In CNC machining of POM plastics, ensuring surface quality is an important challenge. Due to the characteristics of the material, scratches, brushing or other uneven textures may appear on the surface. In order to obtain a smoother surface, it is necessary to adjust the cutting parameters, use suitable tools, and adopt different processing techniques such as finishing or post-processing to improve the surface finish as needed.