The manufacture of precision molds is inseparable from those advanced processing equipment. The main processes of precision mold manufacturing include CNC milling, wire cutting, EDM, grinding, turning, measurement, automation and so on.
1. CNC Milling
From the traditional ordinary milling machine to the three-axis machining center, and then to the current five-axis high-speed milling, the machining of complex three-dimensional profile parts can almost become a reality, and the hardness of the material is no longer a limitation. The main cavity and surface of the plastic mold are completed by CNC milling. The rapid development of the plastic mold manufacturing industry is mainly due to the innovation of CNC milling technology.
2. Slow-moving wire cutting processing
WEDM is mainly used for the processing of two-dimensional and three-dimensional ruled surface parts such as various punching dies, plastic molds, powder metallurgy molds, etc. Among them, the proportion of processing stamping dies is the largest. The processing of many precision holes such as punches, punch fixing plates, concave dies and stripper plates of stamping dies is an indispensable key technology. In the manufacture of injection molds, the common applications are the processing of insert holes, thimble holes, inclined top holes, cavity clearing angles and sliders. Generally speaking, the processing accuracy is not as high as that of stamping dies.
Slow wire processing is a high-precision processing method. High-end machine tools can achieve a processing accuracy of less than 3μm, and the surface roughness can reach Ra0.05μm. At present, the automatic thread cutting of 0.02-0.03 mm electrode wire can be realized, and the practical cutting efficiency can reach about 200 mm2/min.
3. EDM
EDM is suitable for the processing of complex parts such as precision small cavities, narrow slits, grooves, and corners. When it is difficult for the tool to reach complex surfaces, where deep cuts are required, and where the aspect ratio is particularly high, the EDM process is preferred over milling. For the machining of high-tech parts, re-discharge of the milling electrode can improve the success rate, and EDM is more suitable than the high and expensive tool cost. In addition, where EDM finishing is specified, EDM is used to provide a fire pattern surface.