As plastic cools, it shrinks onto the core. If the side walls are perfectly vertical (zero draft), the part will lock onto the mold. Ejector pins will punch through it. Robots will tear it. The operator will curse your name.
Air trapped in the mold has no place to go, resulting in (diesel effect), short shots (incomplete fill), and non-fills . injection mold design guide
The Ultimate Injection Mold Design Guide Designing for injection molding is a balance of physics, material science, and mechanical engineering As plastic cools, it shrinks onto the core
For complex geometries, use metal 3D printing to create cooling channels that follow the contour of the part. This reduces cycle time by 30%+ and eliminates hot spots. Robots will tear it
Below is a comprehensive review of the core principles that define a high-quality mold design guide. 1. Wall Thickness Consistency This is the "golden rule" of injection molding.