A mould design review should leave a record of decisions, open questions and acceptance requirements. The following ten checks help product engineers and tooling buyers organise that review. They are discussion points rather than universal dimensions or a guarantee of defect-free production.
1. Freeze the inputs for the review
Identify the product model revision, material grade, intended production volume and important appearance or assembly requirements. Mark which inputs remain provisional. A recommendation based on an earlier drawing or a different resin should not silently become the approved tooling decision.
2. Agree draft with the release direction
Mark the mould opening direction and review surfaces that resist release. Evaluate draft alongside draw depth, texture, material and the planned ejection method. Some geometry needs a slide, lifter or a part change. Record justified exceptions rather than applying one angle to every surface.
3. Review wall transitions
Inspect thick sections, thin flow paths, ribs and bosses. Autodesk's wall-thickness guidance explains that thickness variation affects filling and cooling. Consider whether coring or a gradual transition can meet the product's function. Where a thick section is necessary, evaluate the resulting process and inspection requirements rather than insisting on a uniform wall at any cost.
4. Choose gates around part requirements
Mark acceptable gate positions and vestige limits. Discuss filling, air escape, weld-line location, appearance and high-load regions together. If simulation is used, record the material and process assumptions. A favourable simulation result still needs comparison with trial evidence.
5. Review cooling with access and maintenance
Discuss temperature control near important features and the ability to connect, seal, clean and maintain the circuits. Balance cooling-channel placement with tool strength and available space. Agree how trial conditions and part stability will be recorded; do not quote a cycle-time reduction before the process has been evaluated.
6. Provide an air-escape plan
Review likely end-of-fill and air-trap locations, including areas affected by inserts or converging flow fronts. Autodesk describes venting analysis as a way to assess trapped-air effects and suitable vent locations. Select vent details for the actual material and tool, then verify filling and surface defects during trials.
7. Check ejection and allowable marks
Confirm support and release around ribs, cores and other features with high release resistance. Mark acceptable ejector locations and appearance restrictions. Review whether the proposed arrangement could deform the part or leave unacceptable marks. Record how this will be checked on samples.
8. Evaluate corners and local transitions
Review abrupt corners, stress-sensitive locations and transitions between adjacent walls. A radius must fit the part's function and mating geometry; avoid replacing all corners indiscriminately. Where a feature remains difficult to manufacture, state the limitation and agree an alternative or a validation plan.
9. Keep shrinkage assumptions traceable
Use information for the actual resin grade and planned process, and record the assumptions behind cavity sizing. Mark critical dimensions and any adjustment allowance. Measure trial samples under agreed conditioning and datum rules before deciding which tooling correction is appropriate.
10. Confirm alignment and acceptance evidence
Review mould alignment, shut-offs and, for multi-shot work, positioning between injections. Specify the sample quantities, dimensional and assembly checks, interface tests where needed, and the issue-closing process. Guide components alone do not guarantee flash-free or dimensionally stable parts.
Send your current drawings, material information and key acceptance requirements to Jump Mould at sales@jumpmould.com to discuss a DFM review. Catalogue photos and concept demonstrations should be distinguished from test reports for a specific project.
Technical references
Autodesk, Wall thickness: https://help.autodesk.com/cloudhelp/2016/ENU/DFM/files/GUID-CFC1BEF6-FD8D-4A66-9D16-5A6BBFEA7BBA.htm
Autodesk, Selecting polymer injection locations: https://help.autodesk.com/cloudhelp/2015/ENU/MoldflowComm/files/GUID-CDD8CC94-4025-4D1B-AE09-E742BA0D633C.htm
Autodesk, Venting analysis: https://help.autodesk.com/cloudhelp/2019/ENU/MoldflowComm-Analyses/files/GUID-03FE6EEA-5294-45C4-8C4F-5B9D34A0BCA5.htm
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