1. The cavity and core are three-dimensional surfaces.
The external and internal shapes of plastic parts are directly formed by the cavity and core. These complex three-dimensional surfaces are difficult to process, especially the blind hole inner molding surface processing of the cavity. If the traditional processing method is used, it not only requires workers with high technical level, many auxiliary fixtures and tools, but also a long processing cycle.
2. High precision and surface quality requirements, long service life requirements.
At present, the dimensional accuracy requirements of general plastic parts are IT6-7, and the surface roughness is Ra0.2-0.1μm. The dimensional accuracy requirements of the corresponding injection mold parts are IT5-6, and the surface roughness is Ra0.1μm or less. The roughness of the laser disc recording surface must reach the level of mirror processing 0.02-0.01μm, which requires the surface roughness of the mold to reach 0.01μm or less.
Long-life injection molds are very necessary to improve efficiency and reduce costs. At present, the service life of injection molds is generally required to be more than 1 million times. Precision injection molds should use mold frames with high rigidity, increase the thickness of the template, and add support columns or conical positioning elements to prevent the mold from deforming under pressure. Sometimes the internal pressure can reach 100MPa.
The ejector device is an important factor affecting the deformation and dimensional accuracy of the product, so the best ejection point should be selected to ensure uniform demolding at all locations. Most high-precision injection molds use inlay or full-split structures in structure, which requires greatly improved processing accuracy and interchangeability of mold parts.
3. Long process flow and tight manufacturing time.
Mold expert Luo Baihui believes that for injection molded parts, most of them are matched with other parts to form a complete product, and in many cases, other parts have been completed and are eagerly waiting for the matching of injection molded parts to be launched. Because the shape or dimensional accuracy of the product is very high, and due to the different characteristics of the resin material, after the mold is manufactured, it is necessary to repeatedly test the mold and correct it, which makes the development and delivery time very tight.
4. Design and manufacture in different places.
Mold manufacturing is not the ultimate goal, but the final product design is proposed by the user. The mold manufacturer designs and manufactures the mold according to the user's requirements. In most cases, the injection production of the product is also carried out by other manufacturers. This results in the situation where the product design, mold design and manufacturing, and product production are carried out in different places.
5. Professional division of labor and dynamic combination.
The mold production batch is small, generally belonging to the production of single pieces, but the mold requires a lot of standard parts, from large mold frames to small ejectors. These cannot and cannot be completed by only one manufacturer alone, and the manufacturing process is complicated, and the use of ordinary equipment and CNC equipment is extremely unbalanced.
