First, let’s analyze what factors are related to surface roughness:
1. Processing materials. Plastic materials are relatively soft, and the tip of the tool is prone to built-up edge. During the processing, the built-up edge will produce grooves on the surface of the workpiece. If it falls off, it will also form hard spots, affecting the surface quality. Brittle materials are relatively hard and prone to vibration. The cutting is granular and pitting is easy to form on the processed surface.
2. Cutting amount. Choosing different cutting parameters will also affect the surface roughness. When the back feed or feed amount is very small and the blade is not sharp enough, the blade is easy to slip on the surface of the workpiece, increasing the surface roughness.
3. High-frequency vibration during cutting. The high-frequency vibration of the machine tool system causes a slight vibration in the relative position of the workpiece and the tip of the tool, increasing the surface roughness.

How to avoid these problems?
First, choose a blade with a large rake angle and sharp edge, choose a coating with low affinity to the workpiece, reduce the amount of cutting when cutting at low speed, choose a cutting fluid with good cooling and lubrication effects, choose a tool handle and tool rod with good rigidity, and when using a smooth surface of the cutter head, only one blade can be installed, and high-speed progressive feeding can be used for processing.