news

What are the common problems in plastic mold design?

Update:10-09-2021
Summary:

In many industrial products, the requirements for produ […]

In many industrial products, the requirements for product size, shape, etc. are relatively high. Therefore, plastic mold designers are required to use plastic to carry out reasonable mold design to improve the production efficiency of industrial products. However, in the process of plastic mold designers designing corresponding molds, there are often some problems, such as different tolerances of plastic molds, different shrinkage rates, and different degrees of cooling, which seriously affect the efficiency of plastic mold design.

First, the tolerances are not uniformly marked. For different products, different proportions of plastic molds are required. If the tolerance mark is low, the precision of the plastic mold will not be high. If the tolerance mark is high, the processing technology of the plastic mold will be relatively complicated. Therefore, when the designer designs the plastic mold, the first consideration is Plastic mold tolerance marking problem. However, in the actual design process, some designers still choose tolerance labels based on their experience, causing errors in the size and shape of the plastic mold, affecting the quality and reference value of the plastic mold design;

Second, the shrinkage rate varies. In the process of making a plastic mold, it is necessary to melt the plastic into a liquid under high temperature or high pressure, and then inject it into the corresponding mold cavity. In the shaping process of liquid plastics, the size of the plastic mold will be slightly smaller than the mold cavity due to the characteristics of the plastic itself. This situation is called shrinkage. In the process of designing plastic molds, designers must take into account the shrinkage. However, some designers do not realize that different types of plastics have different shrinkage rates, and a unified standard cannot be used to calculate the shrinkage rate. Once the shrinkage rate is calculated incorrectly, the size of the plastic mold will also be affected;

Third, the coefficient of thermal expansion varies. Different plastic materials have different thermal expansion coefficients, which directly affect the shape and size of the plastic after cooling. Therefore, when designing a plastic mold, the designer must take the coefficient of thermal expansion into account, and appropriately adjust the design size of the plastic mold according to the actual situation. However, some designers did not strictly abide by the design process and ignored the utilization of the thermal expansion coefficient, resulting in a certain difference between the plastic mold after cooling and the actual demand plastic mold, which in turn affected the design efficiency of the plastic mold.

PREV:       It is the last article