Views: 0 Author: Site Editor Publish Time: 2025-04-22 Origin: Site
DFM (Design for Manufacturing) is the process of optimizing product designs to simplify manufacturing, reduce costs, and improve part quality. In injection molding, DFM focuses on:
Material selection (e.g., ABS, PP, PC)
Moldability (avoiding complex geometries that increase tooling costs)
Production efficiency (minimizing cycle time and defects)
A well-executed DFM process helps prevent common issues like sink marks, warpage, short shots, and ejection problems.
Why? Uneven walls cause sink marks (due to uneven cooling) and warpage.
Rule of Thumb: Maintain wall thickness between 1.5–4mm (varies by material).
Solution: Use ribs or coring for thicker sections.
Why? Prevents part sticking in the mold and reduces ejection force.
Recommended:
0.5°–1° for textured surfaces.
1°–3° for smooth surfaces.
Why? Thick ribs cause sink marks.
Best Practices:
Rib thickness ≤ 60% of main wall thickness.
Add fillet radii (R) to reduce stress concentration.
Why? Affects part appearance, strength, and filling behavior.
Common Gate Types:
Edge gate (simple, low cost).
Submarine (tunnel) gate (auto-degating).
Hot runner gate (for high-volume production).
Why? Undercuts require sliders or lifters, increasing mold complexity.
Solution:
Redesign to eliminate undercuts.
Use flexible materials (e.g., PP) for snap-fits.
Why? Sharp corners create stress points and weaken the part.
Recommended: Minimum 0.5mm radius on all edges.
Why? Poor placement leads to flash (excess material leakage).
Best Practice: Position parting lines on non-cosmetic surfaces.
To validate designs before tooling, engineers use:
Mold Flow Simulation (e.g., Autodesk Moldflow, Moldex3D)
Predicts filling, cooling, and warpage.
3D Printing Prototypes
Tests form, fit, and function before mold fabrication.
DFM Checklists
Ensures all critical design rules are followed.
✅ Lower Costs – Fewer mold revisions & reduced scrap.
✅ Faster Time-to-Market – Avoids late-stage design changes.
✅ Higher Quality – Minimizes defects like warping and sink marks.
✅ Better Supplier Collaboration – Clearer communication with mold makers.
| Aspect | DFM Approach | Traditional Approach |
|---|---|---|
| Design Focus | Manufacturability + Function | Function-first, fix later |
| Modification Cost | Low (early changes) | High (post-tooling changes) |
| Team Involvement | Designers + Mold Engineers | Designers only, late feedback |
Apple’s iPhone Housing – Optimized wall thickness & gate design for precision.
Automotive Components – DFM reduces part weight while maintaining strength.
DFM is essential for efficient, cost-effective injection molding. By following best practices—such as uniform wall thickness, proper draft angles, and smart gate placement—engineers can avoid costly mistakes and produce high-quality plastic parts.
