About polishing and maintenance of injection molding machine(2)

About polishing and maintenance of injection molding machine

1. The effect of different hardness on the polishing process
The increased hardness increases the difficulty of grinding, but the roughness after polishing decreases. As the hardness increases, the polishing time required to achieve a lower roughness increases accordingly. At the same time, the hardness increases and the possibility of excessive polishing decreases accordingly
2. The effect of workpiece surface condition on polishing process
During the crushing process of steel machining, the surface layer will be damaged by heat, internal stress or other factors. Improper cutting parameters will affect the polishing effect. Therefore, high-speed CNC finishing is required, and the cutting amount is controlled at 0.05mm ~ 0.07mm.

The surface after EDM is more difficult to grind than the surface after ordinary mechanical processing or heat treatment. Therefore, before the end of EDM, precision quasi-EDM should be used for trimming, otherwise the surface will form a hardened thin layer. If the electric spark finishing standards are not properly selected, the depth of the heat-affected layer can be up to 0.4 mm.
The hardness of the hardened thin layer is higher than the hardness of the substrate and must be removed. Therefore, it is better to add a rough grinding process to completely remove the damaged surface layer to form an average rough metal surface, which provides a good basis for polishing.