There are many factors to take into account when designing a plastic part for manufacturability. First, it is important to create parts around functional needs by considering design intent and the end-use. Also, it is essential to consider reducing weight and costs, eliminating fabrication and assembly steps, improving structural components, and getting the final products to market quicker. To make sure that your custom plastic products design goals are met, consider the following factors:
Usually, plastic part and product manufacturers choose a familiar grade of plastic from a similar application or depend on supplier recommendations. While resins picked this way might be adequate, they are rarely optimal. Choosing plastic is a complex task that includes a lot of considerations such as temperature, chemical resistance, agency approvals, assembly, cost, finish, and availability.
Considering radius in regards to the thickness of the part eliminates the possibility of having areas with high stress and part breakage. Generally, the thickness at a corner must be in the range of 0.9 times the normal thickness to 1.2 times the part’s nominal thickness.
The Thickness of the Wall
When designing your plastic part, you want consistency in wall thickness to avoid a lot of part defects which can take place during the manufacturing process. As plastic melts, it flows to the areas with least resistance. Parts with inconsistent thickness throughout will cause the melt to flow into the thick areas first, depending on the gate locations. If this happens, the thin areas of the part may not fill properly. Also, thicker areas are expected to cool more slowly and are at risk for sinking defects.
Placement of the Gate
Gates are important to make sure the sine flows properly into the plastic mold. These are small components of the design that direct the resin’s flow from the runners to be distributed throughout the part. The overall quality and viability of a plastic part are affected by the kind of gate used and its placement.
This refers to the amount of taper on the part’s vertical walls. It’s important to ensure the part does not eject from the mold or sustain damage during ejection. Usually, the draft needs to have between 1° and 2° angles, although this requirement varies depending on part restrictions and specifications.
Sometimes, ribs may be included to help in reinforcing the strength of the part. The thickness of the rib is usually between 50% and 70% of the relative part, depending on the material used.