1. Lock the material assumptions
Specify the resin family, grade, reinforcement, color, shrinkage data and any recycled-content restrictions. Mechanical, thermal, chemical, appearance and regulatory requirements should support the material choice. A change from unfilled resin to glass-filled resin can affect shrinkage, warpage, wear and surface appearance.
2. Review wall thickness and transitions
Consistent wall thickness helps filling and cooling. Where thickness must change, use gradual transitions. Heavy sections can create sink, voids and longer cycles, while very thin sections may demand higher pressure or a different gate strategy.
3. Add draft with the finish in mind
Draft supports clean ejection and protects texture. The required angle depends on depth, resin, surface finish and grain specification. Textured walls generally require more draft than polished surfaces.
4. Check ribs, bosses and attachment features
Ribs and bosses should provide stiffness and fastening without creating unnecessary mass. Review their thickness, root radius, height, spacing, support and relationship to visible surfaces. Screw-boss design should match the selected fastener and assembly load.
5. Identify every undercut
Undercuts drive slides, lifters, collapsible cores or design changes. Each mechanism adds tool complexity, maintenance and cycle considerations. Confirm whether the feature is functional, cosmetic or avoidable.
6. Separate critical tolerances from default tolerances
Mark dimensions that control function, fit, sealing, appearance or downstream assembly. Tolerances should account for resin shrinkage, tool construction, measurement method and production environment. Over-tolerancing every dimension raises cost without improving the product.
7. Review gate, weld line and ejection locations
Gate vestige, weld lines and ejector marks must be compatible with cosmetic and functional surfaces. The DFM should identify likely locations and explain any effect on strength, appearance or assembly.
8. Define validation before tool approval
Agree on sampling stages, dimensional layout, appearance standards, functional tests, capability expectations and customer documentation before the mold build begins. This keeps tool acceptance tied to measurable requirements.
Createch supports product development and DFM, precision mold manufacturing and production molding.