Five major steps in the production process of injection molds

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 and study whether its plastic products are in line with the injection molding processing principles, which requires careful consultation with the designer of the products, has reached a consensus. This includes the geometry of the product, dimensional accuracy and appearance requirements, the necessary discussion, and trying to avoid unnecessary complications in mold manufacturing.

The second, the mold structure design.

A set of high-quality mold, not only need to have good processing equipment and skilled mold manufacturing workers, another very important factor is to have a good mold design, especially for complex molds, the good or bad mold design accounts for more than 80% of the quality of the mold. An excellent mold design is: under the premise of meeting the requirements of customers, making the processing cost low, processing difficulty is small, the processing time is short.



To do this, not only to fully digest the requirements of the guests but also to understand 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. figure out every detail in each set of mold design and understand the purpose of each part in the mold.

2. Make more references to similar designs in the design, and understand the situation when it molds processing and product production, and learn the experience and lessons from it.

3. Learn more about the working process of injection molding machines to deepen the relationship between mold and injection molding machines.

4. Go down to the factory to understand the process of processed products, and recognize the characteristics and limitations of each processing.

5. Understand the test mold results and mold changes of the molds you designed, and learn lessons.

6. Try to adopt the previous more successful mold structure in the design.

7. Understand more about the influence of mold on the water on the products.

8. Study some special mold structures and understand the latest mold technology.

Third, determine the mold material and choose standard parts.

In the selection of mold materials, in addition to the precision and quality of the product to consider, but also combined with the actual ability of the mold factory processing and heat treatment to give the right choice. In addition, in order to shorten the manufacturing cycle, as far as possible to use the existing standard parts.

Fourth, parts processing and the mold assembly.

In addition to the accuracy of the mold in the design to give the best structure and reasonable tolerance fit, parts processing and mold assembly are essential. Therefore, the processing accuracy and processing method of choice in mold manufacturing occupy an absolutely dominant position.

The dimensional error of the molded products is mainly composed of the following parts.

1, the manufacturing error of the mold is about 1/3

2, mold wear caused by the error of about 1/6

3、The error caused by the uneven shrinkage of the molded parts is about 1/3

4、The error caused by the inconsistency between the scheduled shrinkage and the actual shrinkage is about 1/6

Total error = (1)+(2)+(3)+(4)

Therefore, in order to reduce the mold manufacturing error, the first should improve the processing accuracy, with the use of CNC machine tools, this problem has been well controlled. In addition, in order to prevent the error caused by mold wear and deformation, the cavity, core, and other key parts should be quenched when processing molds with high precision requirements and large product output. In the medium and large mold, in order to save material and facilitate processing and heat treatment, mold design should be used as far as possible to put together the structure.

In order to solve the uneven shrinkage of the molded parts and the scheduled shrinkage and the actual shrinkage of the error arising from inconsistency, in the mold manufacturing, generally choose 1/3 of the product tolerance, as the mold manufacturing tolerance, the purpose is to give the molding process in the future to leave a larger adjustment margin, in order to solve the error caused by the molding process.

Fifth, test mold.

A set of mold from the beginning of the design to the completion of assembly, only to complete its entire manufacturing process of 70% to 80%. For the predetermined shrinkage and the actual shrinkage of the error caused by inconsistency, the smoothness of the mold release or not, cooling effect, especially the size, location, shape of the gate on the accuracy of the product and the impact of the appearance, etc., must be tested through the test mold. Therefore, a mold test is an indispensable step to check whether the mold is qualified and to choose the best molding process.