Don’t forget the necessity of this process. Quickly review the injection molding process: the two parts of a mold are hollow with negative images of your parts. Hot, liquefied plastic or rubber is injected into the mold to cool. When the injection mold design is cooled, pull the two halves of the mold apart and release.

In this process, there are a few points to remember. Overview:

• During the injection molding process: The injection molded substrate must have a position on the mold and parts. This is called a gate and must be removed from the completed part (either automatically or manually). The gate location is important in injection molding design – you usually want to position the gate on the thicker cross-section of the part so that it can be removed without regard to the structural integrity of the part. The removal of the door may also leave a scar – this needs to be considered, as part of the appearance is a problem.
• During cooling: Liquid plastic or rubber material shrinks as it cools and solidifies. Be sure to take this into account – not only when arranging part sizes, but also design elements, such as increasing the radius at the corners and considering the wall thickness.
• During the release of the part: When the two parts of the mould are separated, there will always be a so-called “parting line”, which is a natural combination of the fact that the two parts are moulded. This is different from drafts, which are caused by defects in the mold or machine and cannot be avoided – it is best to design your part to plan the position of the parting line.