1, The cavity and core are three-dimensional.
The external and internal shapes of plastic parts are directly formed by the cavity and core. The processing of these complex three-dimensional profiles is relatively difficult, especially the processing of the blind hole inner molding surface of the cavity. If traditional processing methods are used, not only It requires workers to have high technical level, many auxiliary tools, fixtures, and tools, and the processing cycle is long.
2, High accuracy and surface quality requirements are required, as well as long service life.
At present, the dimensional accuracy requirements of general plastic parts are IT6-7 and the surface roughness Ra0.2-0.1μm. The corresponding dimensional accuracy requirements of injection moulding parts are IT5-6 and the surface roughness Ra0.1μm or less.
The roughness of the recording surface of the laser disk must reach the level of mirror processing of 0.02-0.01 μm, which requires the surface roughness of the mold to be less than 0.01 μm. Long-life plastic injection mould is necessary to improve efficiency and reduce costs. At present, the service life of injection mould is generally required to be more than 1 million times.
Precision plastic injection mould need to use a mold base with high stiffness, increase the thickness of the template, and add support columns or tapered positioning elements to prevent the mold from deforming under pressure. Sometimes the internal pressure can reach 100MPa.
The ejection 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 demoulding everywhere. High-precision injection molds mostly use inlaid or fully assembled structures in structure, which requires the processing accuracy and interchangeability of mold parts to be greatly improved.
3, The process flow is long and the manufacturing time is tight.
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 the injection molded parts are eagerly awaiting the launch of the supporting parts. Because the shape or dimensional accuracy of the product is very high, and due to the different characteristics of the resin materials, repeated mold trials and corrections are required after the mold is manufactured, making the development and delivery time very tight.
4, Professional division of labor and dynamic combination.
Mold production batches are small and generally belong to single-piece production. However, molds require a lot of standard parts, ranging from mold bases to ejector pins. These cannot and cannot be completed by only one manufacturer alone, and the manufacturing process is complex, ordinary equipment and CNC Equipment usage is extremely uneven.
