What are the requirements of injection mold design

1. Analyze the structure and technical requirements of plastic parts in depth. The structure of plastic parts determines the complexity of the injection mold structure, and the technical requirements of plastic parts (dimensional accuracy, surface roughness, etc.) determine the difficulty of the injection mold manufacturing and molding process. Therefore, for the special requirements of plastic injection molding, unreasonable structural shape, etc., the improved design scheme of injection molding parts should be proposed, otherwise it will increase the difficulty of the injection mold design and manufacturing and injection molding process.

2. Be familiar with the technical specifications of the injection molding machine. The technical specifications of the injection molding machine restrict the size of the injection mold and the range of injection molding products that can be molded.

3. Understand the processing and processing properties of plastics. It includes the flow position of plastic melt, the larger flow distance ratio that the melt can reach, the analysis of the flow resistance in the runner and cavity, the discharge of the original air in the mold cavity, the possible crystallization, orientation and internal stress caused by the plastic in the injection mold, the cooling shrinkage and compensation of the plastic, and the requirements of the plastic on the temperature of the injection mold.

4. Consider the design and manufacture of injection mold, and mainly solve the following problems.
a. The injection mold structure should be reasonably selected. According to the drawings and technical requirements of plastic parts, research and select appropriate molding methods and equipment, combine the mechanical processing capacity of the factory, put forward the injection mold structure plan, fully solicit the opinions of relevant parties, and carry out analysis and discussion, so as to design the injection mold with reasonable structure, reliable quality and convenient operation. If necessary, the requirements for modifying the drawings of plastic parts can be put forward according to the needs of injection mold design and processing, but it can only be implemented with the consent of the user.
b. The dimensions of parts and components formed by injection molding shall be calculated correctly. Formed parts are the direct factors to determine the shape, size and surface quality of plastic parts, which are very important and need special attention. When calculating the size of formed parts, the average shrinkage method can generally be used. For plastic parts with high precision and need to control the allowance for mold repair, the tolerance zone method can be used to calculate. For large precision plastic parts, the analogy method can be used to calculate the shrinkage rate of the measured plastic parts in different directions as far as possible to compensate for the influence of some factors that are difficult to consider in theory.
c. The designed injection mold shall be easy to manufacture. When designing injection moulds, try to make the designed injection moulds easy to manufacture and cheap. Especially for those complex shaped parts, it is necessary to consider whether to use general machining methods or special machining methods. If special processing methods are used, how to assemble after processing, and similar problems need to be considered and solved when designing the injection mold. At the same time, the mold repair after the mold test should also be considered, and enough mold repair allowance should be left.
d. The injection mould designed shall be efficient, safe and reliable. This requirement involves many aspects of injection mold design, such as the gating system needs to be filled and closed, the temperature control Xirong is good, and the release mechanism is flexible and reliable.
e. Injection mold parts shall be wear-resistant and durable. The durability of injection mold parts affects the service life of the entire injection mold. Therefore, when designing such parts, not only the necessary requirements for their materials, processing methods, heat treatment, etc., but also the pin parts such as push rods are easy to get stuck, bent, and broken, and the resulting failures account for most of the injection mold failures. For this reason, it is also necessary to consider how to adjust and replace conveniently, but it is necessary to note that the service life of parts is compatible with the injection mold.
f. The structure of injection mold should adapt to the molding characteristics of plastics. When designing the injection mold, we should fully understand the molding characteristics of the plastic used and try to meet the requirements, which is also an important measure to obtain high-quality plastic parts.