Mold Approval Risk Checklist: Before You Sign Off the Tool

Mold approval is the moment your leverage changes. Before sign-off, corrections are the supplier’s obligation; after it, they’re negotiations. This checklist is the final gate—run it after the T1 sample review says “close enough” and before anything is signed. It exists to catch the approvals that feel fine and cost money later. The mold approval decision explainer frames the same approve / condition / hold call as an animated walkthrough.

Defect Status

• No open structural findings: cracks, voids in loaded bosses, weak weld lines at load — these hold approval automatically
• Cosmetic findings either corrected or explicitly accepted into the standard (what you wave through becomes the spec)
• Stress whitening and ejector marks classified: inherent vs fixable, in writing
• Every fix verified on parts, not promised (“will polish” ≠ polished)
• Worst cavity reviewed, not just the best one

Dimensional & Functional Status

• Critical dimensions in tolerance on the dimensional report—or deviations formally concession-ed with your engineering’s sign-off
• Cavity-to-cavity spread reviewed against tolerance (per-cavity data for multi-cavity tools)
• Assembly/fit verified with real mating parts where they exist
• Loaded features tested (clip cycles, boss torque) on samples from this tool

Process & Stability

• Demonstrated cycle within agreed range of the quoted cycle—gap explained and priced if permanent (see cycle time)
• Ejection unassisted; no release-spray dependence (sticking unresolved = not ready)
• Process record complete and retained—the recipe that made the approved samples is reproducible
• Material confirmed: specified grade, CoA on file, regrind policy stated

Documentation Package

• Dimensional report, process record, and issues-list closure status all on file
• Approved (“golden”) samples retained by both parties, labeled
• Acceptance standard updated with everything this trial decided (cosmetic zones, witness marks, color reference)
• Tooling documentation per the tooling guide: tool data, steel certs where agreed, maintenance expectations
• Tool ownership and transfer rights confirmed in writing—cheapest to confirm now, expensive to discover later

Commercial Closure

• Outstanding corrections priced and scheduled (who pays, by when)
• Spare/wear parts and maintenance responsibilities agreed
• Production release conditions written: what quantity, after which verification

The Decision

• Approve — all sections clear
• Approve with conditions — every open item has an owner, a date, and a verification method in the sign-off document
• Hold — any structural finding, unexplained variation, missing documentation, or unverified fix

A held approval costs days. A wrong approval costs the program. When in doubt, the next trial is cheaper than the first recall.

Evidence Box

This buyer review note was developed from recurring shop-floor troubleshooting patterns, injection molding process principles, and buyer-side mold trial review logic. Where specific technical claims affect supplier evaluation, material handling, tooling decisions, or production approval, they should be verified against the actual mold design, material grade, supplier processing guide, process sheet, and sample inspection data.

This page is a buyer-side review aid, not a final engineering diagnosis, supplier certification, or guaranteed fix.

Related PTA Resources

• T1 Sample Review Checklist
• Mold Trials (T1/T2): What Buyers Should Expect
• Tooling and Production
• Mold Transfer Checklist

Disclaimer

PlasticsTechnologyAlliance.com is an independent buyer resource. This checklist supports—but does not replace—your engineering review, quality procedures, and contracts. Approval criteria should reflect your part’s actual risk level and industry requirements.