Injection Mold Design - Guide

Plastic materials shrink as they cool, and mold designers must compensate for this in the tool dimensions.

: A minimum font size of 20 points is recommended to ensure the plastic resin can flow into every part of the letter.

Incorporate a cold slug well at the base of the sprue to catch the initial, colder stream of plastic. Runner Systems injection mold design guide

Used in hot runner systems. They eliminate runner scrap completely and feed directly into the top of the part, leaving a minimal vestige.

Is the ejection system robust enough to prevent part damage? Plastic materials shrink as they cool, and mold

I can provide specific adjustments for shrinkage, gating, and steel selection based on your application. Share public link

Before a single line of the mold is drawn, the part itself must be optimized. You cannot design a good mold for a bad part. Key considerations include: Runner Systems Used in hot runner systems

Draft is the taper applied to the faces of the part parallel to the direction of the mold opening. Without draft, the part will scrape against the cavity walls during ejection, causing drag marks and part deformation. : 0.5 degrees for smooth surfaces.

: Use these features to add strength or provide attachment points without thickening the main walls.

As plastic fills the mold, air trapped inside the cavity must escape. Inadequate venting causes "burn marks" (dieseling) because compressed air heats up drastically and scorches the plastic.