How does injection mold design work?

How does injection mold design work?

The working principle of injection mold design is mainly divided into three stages: injection stage, cooling stage and release stage.

1. Injection molding stage

This is the core of injection mold design. First, the plastic particles are heated, stirred and melted in the screw of the injection molding machine to transform into a molten state. The screw then pushes the molten plastic into the cavity of the mold. In this process, the injection pressure, injection speed, and the position and speed of the screw need to be precisely controlled to ensure that the plastic can fill the cavity evenly and without defects.

2. Cooling stage

The plastic is cooled and shaped in the cavity. To achieve this, molds are usually designed with cooling channels to provide a uniform cooling environment for the plastic during its cooling process. The length of cooling time directly affects the dimensional accuracy and performance of plastic products. Therefore, the design of cooling system is also an important part of injection mold design.

3. Release stage

When the plastic product is cooled and set, it needs to be removed from the mold. This is usually achieved through an ejector mechanism, such as a thimble or top plate. The ejector mechanism pushes the product out of the mold under the action of the injection molding machine. At the same time, the side pumping mechanism may also be used to assist the release, ensuring that the product can be smoothly and completely removed from the mold.

In addition to the above three main stages, injection mold design also needs to consider other factors, such as the strength of the mold, stiffness, wear resistance, corrosion resistance and other performance requirements, as well as the mold manufacturing, maintenance and other factors. Therefore, a successful injection mold design needs to consider a number of factors, including the structure and performance of plastic products, the choice of mold materials and heat treatment, the design of the pouring system, the design of the molding parts, the design of the cooling system and repair and maintenance.

In general, the working principle of injection mold design is that under a certain temperature and pressure, the plastic that is heated and melted is injected into the mold by the injection machine, and under the action of high pressure, the plastic is formed and cooled. Its main working principle is divided into injection molding, cooling and demoulding three stages. In the design process, many factors need to be considered to ensure the stability and reliability of the mold, and improve production efficiency and quality.