• 2024-04-22
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What are the 4 stages of injection molding?

The injection molding process can be broken down into four main stages:

1. Clamping: Before the injection process begins, the two halves of the mold must be securely closed by the clamping unit. Once the mold is securely clamped, the injection process can begin.

2. Injection: In this stage, the plastic pellets are fed into the injection molding machine and moved towards the mold by the injection unit. During this process, the material is melted by heat and pressure. The molten plastic is then injected into the mold (which is still clamped under pressure) at a high speed and pressure.

3. Cooling: The molten plastic that has been injected into the mold begins to cool as soon as it makes contact with the interior mold surfaces, and solidifies into the shape of the part. During this cooling process, more material is added to ensure the mold maintains its form as the part shrinks.

4. Ejection: After the part has cooled and fully formed, it's then ejected from the mold either manually or automatically. After ejection, the parts are inspected to ensure they meet quality standards. Note that some machines have an automatic de-molding feature where the parts are automatically removed from the mold once the mold is opened.

It's worth noting that while these four stages constitute the core process of injection molding, a lot more occurs within each stage, including a variety of checks and balances to ensure the quality and reliability of the final product.