Every plastic part manufacturer will want to get their products to the market fast and on budget. Both project manufacturers and their injection molding partners cite the design as the step that can greatly affect the production outcomes.
Designing a plastic part that will be manufactured later includes many considerations that can significantly impact major variables. Some manufacturers do not account for design adaptations in their timelines but collaborating with injection molders early in the process is likely to disclose design aspects that can be optimized to enhance part production efficiency and performance.
Keep reading to learn about the steps involved in designing plastic parts for manufacturability:
Calculating Draft Angles
With draft angles, a finished, cooled part can be easily released from the mold. During the release of the part, it is essential to reduce friction to ensure the parts don’t get damaged, offering a uniform surface finish and reducing mold wear and tear.
A part must be designed with sufficient draft and design engineers usually recommend minimum draft angles of 1.5 degrees for core and 1.0 degrees for the cavity. When the manufacturer wants a textured surface, more draft is needed. This is also true when the tool design has steel shut off surfaces.
Analyzing the Thickness of the Wall
When designing a plastic part, it is essential to achieve proper and uniform wall thickness to minimize the risk of structural and cosmetic defects in parts. The typical thickness of part walls ranges from 1.04 to .150 for the majority of resins; however, a molder like Fibertech or design engineer can verify thickness specifications for the material to be used. It is important to analyze wall thickness in the part design process to avoid producing non-functional parts.
Identifying Proper Ribs Placement, Thickness, and Length
Ribs are meant to strengthen a part’s wall while maintaining wall thickness. Good rib design will shorten the length of mold flow and ensure the proper connection of ribs to improve part strength. The ribs must not be greater than 2/3 of the wall thickness, depending on the material used. Wider ribs can create design and sinking problems. Moreover, rib length must not be more than 3 times the wall thickness’ length to avoid part shorting.
Ensuring Optimal Gate Placement
A gate refers to the location where molten plastic material flows into the cavity of the mold. The location of the gate impacts the polymer molecules’ orientation and the way the part will sink during the cooling process.