As a supplier specializing in POM plastic shell CNC Swiss turning, I understand the critical role that selecting the appropriate cutting tool material plays in achieving high - quality machining results. In this blog, I will share some insights on how to choose the right cutting tool material for CNC Swiss turning of POM plastic shells.
Understanding POM Plastic
POM (Polyoxymethylene), also known as acetal or Delrin, is a high - performance engineering plastic. It has excellent mechanical properties, including high stiffness, low friction, and good dimensional stability. However, POM also has some characteristics that pose challenges during machining. It has a relatively low melting point, which means that excessive heat generated during cutting can cause the plastic to melt, deform, or produce burrs. Additionally, POM has a tendency to chip and produce stringy chips, which can interfere with the machining process.
Factors to Consider When Selecting Cutting Tool Material
1. Hardness and Wear Resistance
The cutting tool needs to be hard enough to withstand the cutting forces and resist wear during the machining process. For POM plastic shell CNC Swiss turning, the tool should maintain its sharpness over a long period to ensure consistent cutting quality. Materials with high hardness, such as carbide, are often a good choice. Carbide tools can withstand the abrasive nature of POM and maintain their cutting edge for a relatively long time, reducing the frequency of tool changes and improving productivity.
2. Heat Resistance
As mentioned earlier, POM has a low melting point. Therefore, the cutting tool material should have good heat resistance to prevent the plastic from melting due to excessive heat generated during cutting. High - speed steel (HSS) tools can generate a significant amount of heat during machining, which may not be suitable for POM. On the other hand, carbide tools have better heat dissipation properties and can handle the heat generated during cutting more effectively, reducing the risk of melting the POM plastic.
3. Chemical Compatibility
The cutting tool material should be chemically compatible with POM plastic. Some materials may react with POM, causing surface damage or changing the properties of the plastic. For example, certain types of coatings on cutting tools may interact with POM, leading to discoloration or degradation of the plastic surface. It is important to choose a cutting tool material that has no adverse chemical reactions with POM.
4. Chip Formation and Evacuation
Proper chip formation and evacuation are crucial in CNC Swiss turning of POM plastic shells. Stringy or long chips can get entangled in the cutting tool or the workpiece, causing machining problems such as poor surface finish and tool breakage. The cutting tool material and geometry should be selected to promote the formation of short, manageable chips. Carbide tools with appropriate cutting edge geometries can help break the chips into smaller pieces, facilitating their evacuation from the cutting zone.
Common Cutting Tool Materials for POM Plastic Shell CNC Swiss Turning
1. Carbide
Carbide is one of the most popular cutting tool materials for machining POM plastic shells. It offers high hardness, excellent wear resistance, and good heat resistance. Carbide tools can be ground to very sharp cutting edges, which is beneficial for achieving a smooth surface finish on the POM plastic. There are different types of carbide, such as tungsten carbide, which can be further customized with coatings to enhance its performance. For example, a TiN (Titanium Nitride) coating can improve the tool's hardness and reduce friction, resulting in better cutting performance and longer tool life.
2. Polycrystalline Diamond (PCD)
PCD is an extremely hard cutting tool material. It has excellent wear resistance and can provide a very high - quality surface finish on POM plastic. PCD tools are particularly suitable for high - volume production of POM plastic shells where precision and long tool life are essential. However, PCD tools are relatively expensive, and their use may be limited to applications where the cost can be justified by the high - quality requirements and large production volumes.
3. High - Speed Steel (HSS)
HSS is a traditional cutting tool material. It is relatively inexpensive and easy to grind, which makes it a cost - effective option for small - scale production or prototyping of POM plastic shells. However, HSS has lower hardness and heat resistance compared to carbide and PCD. It may not be suitable for high - speed machining or long - term production runs, as it is more prone to wear and heat - related problems.
Case Studies
In our experience as a POM plastic shell CNC Swiss turning supplier, we have encountered various situations where the choice of cutting tool material had a significant impact on the machining results.
One of our clients required a large - volume production of POM plastic shells with high precision and a smooth surface finish. Initially, we used HSS tools for the machining process. Although the HSS tools were cost - effective at the beginning, we soon noticed that the tools were wearing out quickly, resulting in inconsistent part dimensions and a poor surface finish. After analyzing the situation, we switched to carbide tools with a TiN coating. The carbide tools provided better wear resistance and heat dissipation, allowing us to maintain a consistent cutting quality throughout the production run. The surface finish of the POM plastic shells improved significantly, and the frequency of tool changes was reduced, leading to increased productivity and cost savings.
Another case involved a client who needed a small - batch production of POM plastic shells with complex geometries. For this project, we used PCD tools. The PCD tools were able to cut through the POM plastic with high precision, achieving the required tight tolerances and a mirror - like surface finish. Although the PCD tools were more expensive, the high - quality results and the reduced need for secondary finishing operations justified the cost for this particular application.
Conclusion
Selecting the appropriate cutting tool material for CNC Swiss turning of POM plastic shells is a complex decision that requires a comprehensive understanding of the properties of POM plastic and the characteristics of different cutting tool materials. Factors such as hardness, heat resistance, chemical compatibility, and chip formation should be carefully considered. Carbide, PCD, and HSS are all viable options, each with its own advantages and limitations. By choosing the right cutting tool material based on the specific requirements of the machining project, we can achieve high - quality results, improve productivity, and reduce costs.
If you are interested in POM Plastic Shell CNC Swiss Turning services or have any questions about cutting tool selection for POM plastic machining, please feel free to contact us for further discussion and procurement negotiation. We are committed to providing you with the best solutions for your POM plastic shell machining needs.
References
- Kalpakjian, S., & Schmid, S. R. (2009). Manufacturing Engineering and Technology. Pearson Prentice Hall.
- Boothroyd, G., Dewhurst, P., & Knight, W. A. (2011). Product Design for Manufacturing and Assembly. CRC Press.
- Davies, A. (2008). Machining of Engineering Materials. Butterworth - Heinemann.