For a blog post on "Injection Mold Design," a successful guide must bridge the gap between part aesthetics and manufacturing reality. //upmold.com/plastic-injection-mold-design-guidance/">Upmold and Protolabs . 1. The Golden Rule: Uniform Wall Thickness
Should be 40% to 60% of the nominal wall thickness to prevent sink marks. injection mold design guide
: Maintain consistent wall thickness throughout the part to ensure even cooling. Non-uniform walls lead to sink marks (depressions on the surface), and internal Draft Angles : All vertical walls should have a slight taper (typically 0.5 raised to the composed with power 2 raised to the composed with power For a blog post on "Injection Mold Design,"
Ejector pins leave witness marks. The standard rule for pin placement: The Golden Rule: Uniform Wall Thickness Should be
| Resin | Shrinkage (mm/mm) | Notes | |-------|-------------------|-------| | PP (unfilled) | 0.012–0.022 | Highly crystalline | | ABS | 0.004–0.007 | Good stability | | PC | 0.005–0.007 | Low shrink | | Nylon 6/6 | 0.008–0.015 | Very moisture-sensitive | | POM (Acetal) | 0.018–0.025 | High shrink | | PS | 0.003–0.006 | Amorphous |