Core Tip: Injection mold manufacturing can be roughly divided into the following steps:
Injection mold manufacturing can be roughly divided into the following steps:
First, the process analysis of plastic products.
Before the mold design, the designer should fully analyze whether the plastic products meet the principle of injection molding processing, and need to carefully negotiate with the designer of the products, and reached a consensus. Including the geometric shape, dimensional accuracy and appearance requirements of the product, necessary discussion is carried out to avoid unnecessary complications in the manufacturing of the mold.
Second, the mold structure design.
A set of high-quality molds not only needs good processing equipment and skilled mold manufacturing workers, but also a very important factor is to have a good mold design, especially for complex molds, mold design quality accounted for the quality of the mold 80 %the above. An excellent mold design is: to meet the requirements of the customer, the processing cost is low, the processing is difficult, and the processing time is short. To achieve this, we must not only fully digest the requirements of the guests, but also have an understanding of the injection molding machine, mold structure, processing technology and the mold factory's own processing capabilities. Therefore, to improve the level of mold design, the following points should be achieved:
1. Understand every detail in each mold design and understand the purpose of each part in the mold.
2. In the design of more reference to the previous similar design, and understand the situation in its mold processing and product production, learn from experience and lessons learned.
3. Learn more about the working process of the injection molding machine to deepen the relationship between the mold and the injection molding machine.
4. Under the factory to understand the process of processed products, to understand the characteristics and limitations of each processing.
5. Understand the test results and changes in molds of the molds that they designed, and learn lessons.
6. As far as possible in the design of the previous more successful mold structure.
7. Learn more about the impact of mold water on products.
8. Study some special mold structures to understand the latest mold technology.
Third, 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 necessary to combine the actual capacity of the mold factory for processing and heat treatment to give the right choice. 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 the accuracy of the mold to give the best structure and reasonable tolerances in the design, parts processing and mold assembly is crucial. Therefore, the choice of processing accuracy and processing methods occupies an absolute dominant position in the manufacture of molds. The dimensional error of a molded product mainly consists of the following components:
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 molded parts is about 1/3
4. The error caused by the inconsistency between the predetermined contraction and the actual contraction is about 1/6
Total error = (1) + (2) + (3) + (4)
Therefore, in order to reduce the manufacturing error of the mold, 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, in the mold with high machining accuracy and large product yield, the key parts such as cavity and core should be quenched. In medium and large-sized molds, in order to save materials and facilitate processing and heat treatment, the mold design should be made using a mosaic structure. In order to solve the error caused by the uneven shrinkage of the molded part and the inconsistency between the predetermined shrinkage and the actual shrinkage, the tolerance of the product is generally chosen to be 1/3 when the mold is manufactured. As a manufacturing tolerance of the mold, the purpose is to leave a comparison for the subsequent molding process. Large room for adjustment to solve the errors caused by the molding process.
Fifth, test mode.
A set of molds from the beginning of the design to the completion of the assembly, but only to complete 70% to 80% of its entire manufacturing process. The error caused by the inconsistency between the predetermined shrinkage and the actual shrinkage, the smoothness of the mold release, and the cooling effect, especially the influence of the size, position, and shape of the gate on the accuracy and appearance of the product, must be tested by the test mold. Therefore, trial moulding is an indispensable step for checking the conformity of moulds and selecting the best moulding process.
