Peek, or Polyether Ether Ketone, is a high-performance thermoplastic known for its excellent mechanical properties, chemical resistance, and high-temperature stability. As a leading supplier of Milling machining Peek, we understand the importance of adjusting cutting parameters for different grades of Peek to achieve optimal machining results. In this blog post, we will discuss how to adjust these parameters effectively.
Understanding Different Grades of Peek
Peek comes in various grades, each designed for specific applications. The most common grades include unreinforced Peek, carbon fiber-reinforced Peek, and glass fiber-reinforced Peek. Unreinforced Peek offers excellent chemical resistance and a smooth surface finish, making it suitable for applications in the chemical and food industries. Carbon fiber-reinforced Peek has enhanced strength and stiffness, making it ideal for aerospace and automotive applications. Glass fiber-reinforced Peek provides good dimensional stability and is often used in electrical and electronic components.
Key Cutting Parameters
When machining Peek, several cutting parameters need to be considered, including cutting speed, feed rate, depth of cut, and tool geometry. These parameters interact with each other and can significantly affect the machining quality and efficiency.
Cutting Speed
Cutting speed is the speed at which the cutting edge of the tool moves relative to the workpiece. For unreinforced Peek, a higher cutting speed can be used, typically ranging from 100 to 300 m/min. This is because unreinforced Peek has relatively low hardness and is easier to cut. However, for carbon fiber-reinforced and glass fiber-reinforced Peek, the cutting speed should be reduced to 50 - 150 m/min. The reinforcement fibers can cause tool wear and damage at high cutting speeds, so a lower speed helps to extend the tool life and maintain the cutting quality.
Feed Rate
Feed rate is the distance the tool advances into the workpiece per revolution or per tooth. For unreinforced Peek, a feed rate of 0.1 - 0.3 mm/tooth can be used. This allows for efficient material removal while maintaining a good surface finish. For reinforced Peek grades, the feed rate should be reduced to 0.05 - 0.2 mm/tooth. The reinforcement fibers make the material more brittle, and a lower feed rate helps to prevent fiber pull-out and delamination.
Depth of Cut
The depth of cut is the thickness of the material removed in a single pass. For unreinforced Peek, a depth of cut of 0.5 - 2 mm can be used for roughing operations. For finishing operations, a shallower depth of cut of 0.1 - 0.5 mm is recommended to achieve a smooth surface finish. For reinforced Peek, the depth of cut should be reduced to 0.2 - 1 mm for roughing and 0.05 - 0.2 mm for finishing. The reinforcement fibers can cause tool deflection and breakage at large depths of cut, so a smaller depth of cut is necessary.
Tool Geometry
The tool geometry also plays a crucial role in machining Peek. For Peek machining, tools with sharp cutting edges and appropriate rake and clearance angles are preferred. A positive rake angle helps to reduce cutting forces and improve chip formation. For example, a rake angle of 5 - 15 degrees can be used for most Peek machining operations. The clearance angle should be sufficient to prevent the tool from rubbing against the workpiece, typically ranging from 8 - 12 degrees.
Adjusting Parameters Based on Machining Operations
Different machining operations, such as milling, turning, and drilling, require different cutting parameters.
Milling
In milling operations, the cutting parameters need to be adjusted according to the type of milling (face milling, end milling, etc.). For face milling of unreinforced Peek, a cutting speed of 200 - 300 m/min, a feed rate of 0.2 - 0.3 mm/tooth, and a depth of cut of 1 - 2 mm can be used for roughing. For finishing, the cutting speed can be increased slightly to 250 - 350 m/min, the feed rate reduced to 0.1 - 0.2 mm/tooth, and the depth of cut reduced to 0.1 - 0.5 mm. For reinforced Peek, the cutting speed should be reduced to 100 - 150 m/min, the feed rate to 0.05 - 0.15 mm/tooth, and the depth of cut to 0.2 - 1 mm for roughing. For finishing, the cutting speed can be increased to 120 - 180 m/min, the feed rate to 0.03 - 0.1 mm/tooth, and the depth of cut to 0.05 - 0.2 mm.
Turning
In turning operations, the cutting speed, feed rate, and depth of cut also need to be carefully adjusted. For unreinforced Peek, a cutting speed of 150 - 250 m/min, a feed rate of 0.1 - 0.3 mm/r, and a depth of cut of 0.5 - 2 mm can be used for roughing. For finishing, the cutting speed can be increased to 200 - 300 m/min, the feed rate reduced to 0.05 - 0.15 mm/r, and the depth of cut to 0.1 - 0.5 mm. For reinforced Peek, the cutting speed should be reduced to 80 - 150 m/min, the feed rate to 0.05 - 0.2 mm/r, and the depth of cut to 0.2 - 1 mm for roughing. For finishing, the cutting speed can be increased to 100 - 180 m/min, the feed rate to 0.03 - 0.1 mm/r, and the depth of cut to 0.05 - 0.2 mm.
Drilling
When drilling Peek, the cutting speed and feed rate are critical. For unreinforced Peek, a cutting speed of 80 - 150 m/min and a feed rate of 0.05 - 0.2 mm/r can be used. For reinforced Peek, the cutting speed should be reduced to 40 - 100 m/min, and the feed rate to 0.02 - 0.1 mm/r. Using a sharp drill bit and appropriate coolant can also help to improve the drilling quality.
Importance of Testing and Optimization
It is important to note that the recommended cutting parameters are only guidelines. In practice, the optimal cutting parameters may vary depending on the specific machining equipment, tool materials, and workpiece conditions. Therefore, it is essential to conduct test cuts and optimize the parameters based on the actual machining results. By monitoring the cutting forces, surface finish, and tool wear during the test cuts, adjustments can be made to the cutting parameters to achieve the best possible machining quality and efficiency.
Related CNC Machining Services
In addition to Peek machining, we also offer CNC Machining PMMA, CNC Machining PPSU, and CNC Machining FR4 G10 services. These materials have different properties and require different cutting parameters, but the basic principles of adjusting cutting parameters remain the same.
Contact Us for Procurement and洽谈
If you are interested in our Milling machining Peek services or have any questions about adjusting cutting parameters for different grades of Peek, please feel free to contact us. We have a team of experienced engineers who can provide you with professional advice and solutions to meet your specific needs.
References
- "Plastic Machining Handbook"
- "Advanced Machining of Engineering Plastics"
- Industry research reports on Peek machining
