Injection Molding Process Step By Step Guide

For those who don’t know what injection molding is used for and how it helps in mass productions, this article is a must read.

The Injection Moulding Process – Cycle explained

Injection Molding Process

Today we are going to tell you everything about the injection molding process and the steps that are involved in it. It wouldn’t be wrong to say that this process is so far the best and the most effective way to produce mass product parts.

As the name implies, it’s a process where a mold is prepared and designed as per the shape of the product, and then some material (plastic, metal, glass), etc is melted and then injected inside the mold. It cools down, and the end product comes out.

This process is quite common nowadays, and luckily there are companies like qmolding that can help you here. If you want the best services and the most economical injection molding done, then opt for qmolding, and we assure you that you are going to love what they bring to you.

Other than this, here are the steps involved in this process that you need to know about.

1] The mold closes

The injection molding cycle begins right when the mold closes. In some cases, when it’s a robot involved, the cycle will run from part to part. In other words, the cycle will start and end when the robot receives a new part or when a part prepared touches the conveyor belt.

2] Injection

The next step is where the heated plastic is injected inside the mold. When the melted plastic goes inside the mold, all that displaced air inside is escaped through the vents with the help of injection pins and the parting lines.

This is an important part where it’s important for you to consider the gate, the runner, and the vent design to ensure that the mold is properly filled without any room or space left.

3] Cooling

When the mold is filled, that particular part is then allowed to cool down for a while. A certain amount of time is required here to harden the melted material. The time required for cooling depends on the type of resin that’s being used and the thickness of the part that’s being prepared.

The mold is then designed with the help of internal cooling and heating lines, where a water cycle is used to bring down the temperature of the mold.

4] Plasticizing of the resin

When the parts cool, the barrel screw is brought near the plastic resin, it retracts and draws into the barrel with the help of a material hopper. The required barrel temperature is maintained as per the type of resin that’s being used.

5] Ejection

The next step is that of ejection. This is where the mold opens, and with the help of the ejector rod, the pins are moved forward. There’s a bin placed below the mold, that’s where the product falls and is captured.

6] Removal of the packaging and the runner

A machine is used to separate the usable parts from the runner left over. For those who don’t know, the runner is the pathway taken by the plastic to fill in the mold cavity. These runners help a lot in reducing the overall cost and the impact on the environment.


These are the simple steps involved in the injection molding process. All of them are quite simple, there’s nothing to worry about, and if you just hire the right service provider for this job, you sure will end up impressed and happy with the final result. Now without waiting anymore, look for the right company for this process and get the production started.

About the author

Wilfrid Lee

Wilfrid Lee is the founder of Tech Motus. Working as an SEO Expert, started blogging recently on soul idea of sharing. Being fond of computers, mobiles and gadgets from childhood, would love to share my ideas and knowledge about ever evolving technology.

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