Do you know the reason for the difficulty in making injection molds?

The cavity and core are three-dimensional.

The upper and lower shapes of plastic parts are directly formed by the cavity and core. These complex three-dimensional surfaces are difficult to machine, especially for blind hole cavity surfaces. If traditional processing methods are used, it not only requires workers to have a high level of technical proficiency, multiple auxiliary tools, and cutting tools, but also requires a long processing cycle.

High precision and surface quality requirements, long service life.

At present, the dimensional accuracy requirements for general plastic parts are it6-7, and the surface roughness is Ra0.2-0.1 μ m. The dimensional accuracy requirement for the corresponding injection molded parts is it5-6, and the surface roughness is Ra0.1 μ M and below.

The surface roughness of the laser disc recording surface should be 0.02-0.01 of the mirror processing level μ m. This requires the surface roughness of the mold to be less than 0.01 μ m. In order to improve efficiency and reduce costs, it is necessary to use a long-life injection mold. At present, the service life of injection molds is generally required to exceed 1 million times.

The precision injection mold adopts a rigid mold base, which increases the thickness of the mold and adds support columns or cone positioning components to prevent the mold from being compressed and deformed. Sometimes the internal pressure can reach up to 100MPa.

The spraying device is an important factor affecting product deformation and dimensional accuracy. Therefore, the optimal ejection point should be selected to ensure uniform demolding of all parts. In the structure of high-precision injection molds, most of them adopt splicing or full splicing structures, which requires a significant improvement in the machining accuracy and interchangeability of mold parts.

Long process and short manufacturing time.

For injection molded parts, most of them are complete products that are matched with other parts, and in many cases, they have already been completed on top of other parts, waiting for the matching of injection molded parts to be launched. Due to the high requirements for the shape or dimensional accuracy of the product and the different characteristics of resin materials, after the mold manufacturing is completed, it is necessary to repeatedly test and modify the mold, which makes the development and delivery time very tight.

Remote design and manufacturing.

Mold manufacturing is not the ultimate goal, but the final product design is proposed by the user. According to user requirements, mold manufacturers design and manufacture molds, and in most cases, injection molded products are also produced by other manufacturers. In this way, product design, mold design and manufacturing, and product production are carried out in different places.

Professional division of labor and dynamic integration.

The production batch of molds is small and generally belongs to single piece production. However, molds require a large number of standard parts, from the mold base to the ejector pin, which cannot be completed by a single manufacturer. Moreover, the manufacturing process is complex, and the use of commonly used equipment and CNC equipment is very uneven.