Basics of Injection Molding Design

Injection molding is a widely used manufacturing process for producing plastic parts by injecting molten material into a mold. Designing parts for injection molding requires careful consideration of various factors to ensure manufacturability, cost-effectiveness, and part quality. Here’s an overview of essential design principles:

1. Wall Thickness

Uniformity:Maintain consistent wall thickness to prevent issues like warping and sink marks

Guidelines:

-Standard thermoplastics: 1.5–3 mm

-Thicker sections may require reinforcement or ribbing.

2. Draft Angles

​Purpose acilitate easy ejection of the part from the mol.

Recommendation Apply a draft angle of at least 1° per side, increasing with part dept.

3. Radiiand Fillets

Benefits: Reduce stress concentrations and improve material flw.

Design Tip: Use radii at corners; a minimum inside radius of 0.5 times the wall thickness is advisabe.

4. Undercuts

Challenge: Undercuts complicate mold design and increase cots.

Solution: Design parts without undercuts or use side actions if necessry.

5. Gate Design

Types:

Edge Gat: Common for rectangular prts.

Pin Gat: Suitable for cylindrical prts.

Submarine Gat: Ideal for automatic de-gaing.

Consideration: Gate location affects part filling and appearnce.

6. Ribbing and Coring

Purpoe: Enhance part strength without increasing wall thicness.

Guidelines:

Ris: Should be 40–60% of the adjacent wall thicness.

Corig: Reduces material usage and wight.

7. Hole Design

Best Practices:

Through Hoes: Preferred over blind holes for ease of mlding.

Depth-to-Diameter Raio: Keep it under 2:1 to prevent issues during mlding.

Spacng: Maintain at least the hole diameter between holes or between a hole and the par edge.

8. Surface Finish and Texturing

Considerations:

Texture Dpth: Affects draft angle requiements.

Finish ype: Affects part aesthetics and functinality.

9. Mold Design Considerations

Mold Components:

Core and Cvity: Form the parts shape.

Cooling Chanels: Ensure uniform cooling to preventwarping.

Ejection Sstem: Facilitate part removal withou damage.

10. Simulation and Analysis

Tools: Software like Autodesk Moldflow or SolidWorks Plastics can simulate material flow, cooling, and potentia defects.

Beefits: Identifies issues early, reducing prototyping costsand time.

DAYIN Plastic Products Co., Ltd. is a high-quality injection mold design company and OEM injection mold manufacturer that focuses on home appliance mold manufacturing and provides OEM/ODM services. Founded in 1989, the company is a manufacturing solution provider that integrates Research and injection mold Development and manufacturing services.

If you have specific questions or need further details on any aspect, feel free to ask!