Solid thick region
- Hot spot in steel extends cycle
- Warp risk on opposite flat
- Harder to route uniform cooling
DFM
Cooling Line Layout: Injection Molding Design Rules
Cooling line layout in the mold follows thick sections and flat regions in your part design.
DFM
Cooling layout in the mold follows your wall thickness map
Buyers design geometry. Mold designers route water around thick sections.
Thick regions cool slower and set cycle time on many parts.
Uneven cooling drives warp on large flat covers and brackets.
Part design can reduce thick islands so cooling channels reach steel efficiently.
DFM
Quote this rule with your CAD upload
NetProto DFM review flags these geometry patterns before steel is ordered.
- Call out draw direction and cosmetic faces on the model.
- Note resin family even when the grade is not final.
- Tighten tolerances only on mating features that need them.
Geometry
Thick boss island versus cored section
Cooling follows mass. Coring helps both sink and cycle.
Cored section with ribs
- More uniform cooling path in steel
- Lower sink tendency
- Cycle tied to nominal wall, not boss peak
Related rules
Design guide
Jump to sibling rules before you freeze CAD.
Design guide hub
All DFM topics on one route.
Design guide hubDFM article
Long form engineer guide.
DFM articleThick section design
Coring on the part model.
Thick section designCycle time glossary
Production clock.
Cycle time glossaryUniform wall thickness
Reduce thick islands for cooling.
Uniform wall thicknessVisual reference
Molding context for this rule
Images from the Forge media library illustrate typical programs.
Injection molded part design review on CAD
Injection molded part design review on CAD
Plastic housing with ribs and bosses
Plastic housing with ribs and bosses
Engineer measuring molded component
Engineer measuring molded component
FAQ
Cooling questions
Can buyers specify cooling layout?
State critical flatness and cycle goals. Mold designer routes water.
Does glass fill change cooling?
Filled resins conduct differently. Process development adjusts cycle.
Will NetProto guarantee cycle on quote day?
Cycle targets are set on qualified programs after tooling.
Next step
Show thick sections on section views
Upload CAD sections so DFM can flag hot spots before steel.