Plastic parts precision mold finishing process

Author: MULAN – Plastic Molding Manufacturer

The precision mold of plastic parts is assembled from multiple parts. The quality of the parts directly affects the quality of the precision mold of plastic parts, and finishing is the guarantee of the final quality of plastic parts. Therefore, the control of finishing is very important. According to the appearance and shape of plastic parts, parts can be roughly divided into three categories: plates, special-shaped parts and shafts. The common process flow is roughly as follows: rough machining - heat treatment (quenching and tempering) - fine grinding - electrical machining - fitter (surface treatment) - assembly processing.

1: Heat treatment of plastic parts precision mold parts The heat treatment of plastic parts precision mold parts only needs to make the parts reach the required hardness, and also needs to control the internal stress during the processing to ensure the dimensional stability of the parts. Two: Grinding of precision mold parts for plastic parts There are three main types of grinding machines: surface grinders, internal and external cylindrical grinders and tool grinders. During fine grinding, grinding deformation and grinding cracks should be strictly controlled, even small cracks will be exposed in subsequent processing.

Therefore, the fine grinding feed rate should be small, not large, and the coolant should be sufficient. Three: Electric processing of precision mold parts for plastic parts How can modern plastic precision mold factories lack electric processing? Electric processing can process various special-shaped and high-hardness parts. It is divided into two types: wire cutting and electric spark machining. . The precision of the slow wire cutting method is as high as ±0.003mm, and the roughness is Ra0.2μm.

EDM first needs to make machining electrodes, and the electrodes can be divided into coarse and fine. The design of the finishing electrode requires good shape conformity, and it is best to use CNC machine tools to complete the production and processing. Four: Surface treatment of precision molds for plastic parts The knife marks and wear marks left on the surface of the parts during the processing of precision molds for plastic parts are the places where stress is concentrated and the source of crack expansion.

Therefore, after the precision mold processing of plastic parts, the surface of the parts needs to be strengthened and polished by the fitter to eliminate hidden dangers in processing.