Plastic parts precision mold finishing process


Plastic parts precision molds are assembled from multip […]

Plastic parts precision molds are assembled from multiple parts, the quality of parts directly affects the quality of plastic parts precision molds, and finishing is the guarantee of the final quality of plastic parts, so the control of finishing is very important.

According to the appearance and shape of plastic parts, parts can be roughly divided into three categories: sheet, special-shaped parts and shafts. The common process flow is roughly as follows: roughing - heat treatment (quenching and tempering) - fine grinding - electrical machining - fitter (surface treatment) - assembly processing.

One: plastic parts precision mold for heat treatment of parts material
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 plastic parts precision mold parts
There are three main types of grinders: surface grinders, cylindrical grinders and tool grinders. During fine grinding, grinding deformation and grinding cracks should be strictly controlled, and even small cracks will be exposed in subsequent processing. Therefore, the fine grinding feed should be small, not large, and the coolant should be sufficient.

Three: plastic parts precision mold parts electrical processing
EDM can process all kinds of special-shaped and high-hardness parts. It is divided into wire cutting and EDM. The precision of the slow-moving wire cutting method is as high as ±0.003mm, and the roughness is Ra0.2μm. EDM must first make processing electrodes, and electrodes are divided into coarse and fine. The design of the finishing electrode requires good shape conformity, and it is best to be produced and processed by CNC machine tools.

Four: Surface treatment of precision molds for plastic parts
The tool marks and wear marks left on the surface of the plastic parts during the machining of precision molds are the places where the stress is concentrated and the source of crack propagation. Therefore, after the precision mold of plastic parts is processed, the surface of the part needs to be strengthened and polished by a fitter to eliminate processing hidden dangers.