8 Key Components of an Injection Mold: A Professional Guide

Many businesses are often at a loss when dealing with mold factories. In fact, you can quickly grasp the main points and not be fooled as long as you understand a few key terms! Today, we'll use the simplest way to help you understand the 8 core terms of plastic molds. 

1️. Number of Mold Cavities 

The cavity in the mold determines how many products can be produced in one mold.

 Single-cavity: One can be produced at a time, with low cost but slow production capacity.

 Multi-cavity: 4 or 8 can be produced at a time. It is highly efficient, but the molds are more expensive.

2️. Mold Base

The "foundation and shell" of the mold hold all the parts together.

 Different mold base specifications will affect the strength, service life and price of the mold.

3️.  Cooling System

The "small water pipes" in the mold are used to carry away the heat of the high-temperature plastic. 

If the design is not good, it is prone to shrinkage, deformation and an extended production cycle.

4️. Venting Design

The "small channels" are specially reserved for air in the mold.

 If there is no exhaust port, the air will be trapped → the product will burn and be short-circuited (not filled up).

5️. Mold Core

The protruding part in the mold determines the internal structure of the product. 

For instance, a water cup: its shape is determined by the cavity, and the hollow part inside is formed by the core.

6️. Parting Line

The opening and closing positions of the mold and the fine lines left after the product cools down. 

The small line on the side of the mineral water bottle cap is the parting line.

7️. Gate

The "entrance" through which the plastic melt enters the mold.

 Whether the position design is good or not directly affects the appearance of the product and the uniformity of injection molding. 

8️. Injection Mold Ejection System

The "ejector pin device" in the mold is responsible for pushing the product out of the mold.

 The small dot at the bottom of the transparent plastic cup is the mark left by the thimble.

At SG PROTO, we specialize in custom injection molds designed for high precision, long life, and optimized production efficiency. Whether for prototype molds or mass production, we deliver quality you can rely on.

Partner with us for your next project, and experience the difference that expert mold engineering makes.