Main Components and Functions of Plastic Injection Mold

November 25, 2021

Plastic injection mold and things you need to know

Plastic injection molded parts are always very popular thanks to their convenience and toughness. In addition, plastic products are always more colorful than other materials. All these beloved plastic products are made using plastic injection molds.

So, what is plastic injection mold? This article will help you learn the basic information about plastic injection molds.

What is plastic injection molded parts?

To learn more about plastic injection mold, first, you need to understand the concept of this device. A plastic injection mold is a tool common to shape plastic products. It can be understood simply that a plastic injection mold consists of many parts assembled together.

Therefore, plastic injection molded parts are an important and indispensable part of the production cycle of plastic utensils. Not only plays a role in creating products, but plastic injection molds also ensure that all products have the same structure and size. Therefore, the size of the plastic injection mold and the desired size of the product will be the same.

Plastic Injection Molded Parts

Plastic injection mold is divided into two main parts:

There are many different types of plastic injection molds on the market. You can base on the size as well as the number of products you want to choose the right plastic injection mold for your needs. For example, if you only produce a small number of products, choose a 2-plate mold, instead of using a multi-cavity mold or other high-end construction.

Plastic injection mold construction

The Fixed Part of plastic injection mold(Female mold):

True to its name, this is the fixed part in the injection molding process. Also, this part is fixed to the wall of the plastic injection machine and connected to the plastic injection system of the machine. The purpose is to carry out the injection of molten plastic material into the plastic injection molded parts cavity through the nozzle and runner system.

The movable part of the plastic injection mold

There is a reverse part, the movable part has the function of closing the mold to press the product and opening the mold to take the product. In other words, this movable part can be “portable” – that is, it can be opened and closed flexibly.

The movable part is attached to the wall of the injection molding machine with a mold liner system that helps push the product out through a push pin system designed in the mold.

Main components and functions

Upper clamp plate: Common to fix the upper mold plate and the upper clamp plate into one block, avoiding shifting during operation.

Upper mold plate: This is an important component in the plastic injection mold. It is the outer image of the product. At the same time, the upper plastic injection molded parts plate will also determine the accuracy of the mold. This will accurately shape the product. The surface quality of the product will depend entirely on the machining of this molding plate.

The Positioner parts of the Plastic injection mold

The locator includes the locating pin and the locating silver. Also, this part has the shape of a circle that protrudes above the top of the front clamp plate, allowing the user to insert a corresponding hole in the side of the machine.

The positioner will help the injection nozzle of the press to correctly position with the corresponding position of the nozzle bush (the appropriate position between the fixed part and the movable part of the mold).

Plastic Injection Molded Parts 2021

The Support plate of the plastic injection mold

Anchor keeps the mold piece from falling out. At the same time, it also helps to support the movable plate and create the necessary clearance in the middle. Also, this is very beneficial for the arrangement of the ejector and ejector plate clamps with the battery system.

Bar: Common to make a divider between the support plate and the clamp plate. Similarly, it helps the propeller to operate smoothly.

Lower clamping plate: Common to hold the entire lower plastic injection molded parts assembly into a unified block. At the same time clamp this block to the dynamic table of the plastic injection machine

Push pin: When finished, the mold part will open, this time the push pin will take the product out of the mold

Push clamping plate: Fixed the three parts: push pin, return pin, and stem puller

The Thrust plate of the plastic injection mold

Helps prevent the mounting pins on the ejector clamp from falling while pushing the product out. Also, the push plate and the push clamp plate are formed into a block called the push rod. This unit is located between the lower die and the lower clamp plate.

Return latch: When the mold is closed, the return latch will be the part that helps the push rod return. The return pin helps to ensure that the clamp plate assembly and the ejector plate do not slip out. At the same time, it protects the ejector battery from bending during the process of pushing the product back and forth.

The Pillar of plastic injection mold

Guides the movement and supports the push plate. Prevent the mold plate from bending or deforming due to high pushing pressure. At the same time increase the life of the mold.

Lower mold plate: contour determines the internal shape of the product. The lower mold and the upper plastic injection molded parts will combine to create the complete shape of the part. The upper die is the stationary part, and the lower die is the movable part.

The role of injection molding technology in life

Injection molding technology plays a huge role in people’s lives because it brings a multitude of benefits. Products from injection molding technology often have more beautiful designs and designs than those produced by traditional methods. This enhances the value and quality of products to consumers.


The applications from injection molding technology are extremely diverse and almost appear in our daily life such as household products such as plastic basins, plastic containers, plastic pipes to children’s toys, shells. computer phone…. The plastic injection molded parts process is most commonly common in the packaging, electronics, and refrigeration industries.


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