Part Design For Dummiespdf Exclusive: Injection Molding

Beginners often try to make a part stronger by making it thicker. As we discussed, thick walls lead to sink marks. The professional solution is to use ribs.

This comprehensive guide breaks down the essential rules of injection molding part design into simple, actionable concepts. 1. The Golden Rule: Maintain Uniform Wall Thickness injection molding part design for dummiespdf exclusive

Bosses are cylindrical projections designed to accept screws, pins, or other fasteners. They are essentially small towers of plastic. Just like ribs, a boss that is too thick will cause a sink mark. Therefore, the wall thickness of the boss should follow the same rule: maintain a thickness of about 60% of the nominal wall . If your part's walls are thicker than 4 mm, you can reduce the boss thickness to 40% of the wall. Beginners often try to make a part stronger

The radius of an outside corner should be equal to the inside radius plus the wall thickness. This ensures that the wall thickness remains perfectly uniform around the bend. 6. Design Around the Parting Line and Undercuts This comprehensive guide breaks down the essential rules

The thickness of the base of the rib should be 40% to 60% of the main wall thickness to avoid sink marks on the opposite surface. Bosses are used for fasteners or mounts.

"Ejector pins leave white marks." Fix: Increase ejector pin diameter or add a slight radius to pin tips.