1. Process analysis of plastic products
Before designing the mold, the designer should fully analyze and study whether the plastic product conforms to the principle of injection molding, and needs to negotiate carefully with the product designer, and a consensus has been reached. This includes necessary discussions on the geometric shape, dimensional accuracy and appearance requirements of the product, and try to avoid unnecessary complexity in mold manufacturing.
2. Mold structure design
A set of high-quality molds not only requires good processing equipment and skilled mold manufacturing workers, but also a very important factor is to have good mold design, especially for complex molds, the quality of mold design accounts for 80% of the quality of the mold. %above. An excellent mold design is: on the premise of meeting the requirements of customers, the processing cost is low, the processing difficulty is small, and the processing time is short.
To improve the level of mold design, the following points should be done:
1. Understand every detail in the design of each mold, and understand the purpose of each part in the mold.
2. Refer to the previous similar designs when designing, and understand the situation in its mold processing and product production, and learn from the experience and lessons.
2. Learn more about the working process of the injection molding machine to deepen the relationship between the mold and the injection molding machine.
4. Go to the factory to understand the process of processed products, and recognize the characteristics and limitations of each type of processing.
5. Understand the test results and mold modification of the mold designed by yourself, and learn from it.
6. Try to use the more successful mold structure in the design.
7. Learn more about the influence of water in the mold on the product.
8. Study some special mold structures and understand the latest mold technology.
3. Determine the mold material and select standard parts
In the selection of mold materials, in addition to considering the accuracy and quality of the product, it is also necessary to give the correct choice in combination with the actual ability of the mold factory’s processing and heat treatment. In addition, in order to shorten the manufacturing cycle, the existing standard parts are used as much as possible.
Fourth, parts processing and mold assembly
In addition to giving the best structure and reasonable tolerance in the design, the precision of the mold is very important for the machining of parts and the assembly of the mold. Therefore, the choice of machining accuracy and machining method occupies an absolute dominant position in mold manufacturing.
The dimensional error of molded products is mainly composed of the following parts:
1. The manufacturing error of the mold is about 1/3
2. The error caused by mold wear is about 1/6
3. The error caused by uneven shrinkage of the molded part is about 1/3
4. The error caused by the inconsistency between the scheduled shrinkage and the actual shrinkage is about 1/6
Therefore, in order to reduce the mold manufacturing error, the machining accuracy should be improved first. With the use of CNC machine tools, this problem has been well controlled. In addition, in order to prevent errors caused by mold wear and deformation, quenching should be used for key parts such as cavities and cores in molds with high machining accuracy requirements and large product output.
In medium and large molds, in order to save materials and facilitate processing and heat treatment, the mosaic structure should be used as much as possible in mold design.
5. Test mode
A set of molds is only 70% to 80% of the entire manufacturing process from the start of design to the completion of assembly. For the error caused by the inconsistency between the predetermined shrinkage and the actual shrinkage, whether the demoulding is successful or not, how is the cooling effect, especially the influence of the size, position and shape of the gate on the accuracy and appearance of the product, it must be tested by mold trial.
Mold tryout is an indispensable step to check whether the mold is qualified or not and to choose the best molding process.
After sharing, I hope it helps everyone!
Post time: Jul-21-2022