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Mould Design in Plastic Injection Molding

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  • Mould Design
  • Posted date:
  • 26-04-2017
Mould Design in Plastic Injection Molding

Mould Design in Plastic Injection Molding 

Injection Molding is an extremely versatile procedure.  It can be utilised for virtually any product. Injection molding is the industry standard for manufacturing components for products.

There are some limitation needs to consider. Here are the rules to follow when designing your product to make sure quality and durability:

Wall Thickness

The thickness of wall of your component is directly balanced. This is to consider both the whole materials required to make the part as well as the cooling time needed. Through reducing the utmost thickness of the wall, you lessen both these aspects. This  leads to lessen cycle time, as a result lower the cost of production. 


Corners could be an issue in a mold and will not come out flush. It  is difficult  to form plastic into a flawless corner. The outcome will look amateurish and messy, not to mention the power of the components can be compromised. 

If the wall of your component is inconsistent or too thick you may have an issue. Problems could be caused involving warpage and sinkage. This can  lead  to rejects and expensive redesigns. Make sure the wall thickness is matched to the abilities of the machine.


These are structural factors for your component, utilised for general stability control. Ribs are thin wall protrusions which extend vertically from a plane or wall. Adding ribs instead of thicker walls will provide greater structural support.


These are empty, cylindrical protrusions. These are normally integrated in a style for accepting screws or other mating parts of your style. Making sure these are secured by attaching them a wall. Putting in ribs will means the bosses will stay straight as well as accommodate the part it was made for without an issue.

External Undercuts

A depression or protrusion in the exterior of the mold - the cavity half - could create issues if trying to divide parts from the mold. Adjust the parting line to lodge this.

Internal Undercuts and Overcuts

Related to external undercuts, these depressions or protrusions are within the mold - on the center half. Adjust the parting line to lodge this.


When your mould has a thread, always position it vertical to the parting column. This will make sure that the delicate thread isn't damaged. It's better, preferably, to not comprise a thread at all in the design. Making your design simple will lower the odd of something going wrong.

Injection molding design makes a superior product. The myriad possibilities far outdo the limitations. Designing for an excellent injection molded part is the core of the design process.  These restrictions are the guidelines for making a flexible end product.