Silicone Mold Sample Approval Checklist Before Production
Silicone mold sample approval checklist - dimensions, Shore A, demold test, flash, finish, and sign-off steps before MOQ 50 production at RUUIPON.
Kyler Yang · Founder5 min read
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Approving a silicone mold sample is the gate between 3-7 day prototype and MOQ 50 production - skip a line item and you reorder geometry, not just rubber. RUUIPON sends production-representative samples before batch pour. This checklist is what buyers should verify on the bench.
Quick answer: Sign off only after caliper check on 3+ dimensions, pour test with your production material, flex demold on worst-case cavity, flash trim pass, finish match to reference, and written PO revision lock - email confirmation to [email protected] with photos attached.
Why Sample Approval Is Not "Looks Fine"
A sample tray uses the same platinum silicone, vacuum degassing, mix ratio, and master as MOQ 50 - but cavity count may be 1-4 instead of 12-24. Approval confirms geometry and process, not just aesthetics.
| Check category | Pass threshold (typical) |
|---|---|
| Critical dimensions | ±0.3-0.5 mm vs CAD on agreed points |
| Wall thickness | 2.5-5 mm at caliper spots |
| Cavity spacing | 8-20 mm per layout drawing |
| Cast fill | 95%+ cavities complete on first pour |
| Demold | No tear, no tool pry on flex method |
| Flash | Lip clean - flash QC |
What the Sample Proves (and Does Not)
- Proves - draft, logo depth, release, finish, Shore A feel, parting line placement.
- Does not prove - full-sheet warp on 24-up until production; long-cycle wear (500+ pulls).
- Prototype timeline - 3-7 days after CAD approval. Prototype to production.
- Shrink - tooling ~0.1% on silicone; cast material shrink is separate. Tolerance guide.
Dimensional QC on Receipt
- Caliper finished cavity ID - width, depth, corner radii at 3 locations.
- Compare to STEP/STL - not to a cast part alone (cast shrink stacks).
- Logo emboss - depth gauge or section photo; 0.3-0.6 mm food, 0.5-1.0 mm resin. Logo limits.
- Spacing - edge-to-edge on multi-cavity sample if provided.
- Weight - tray weight logged for freight planning. Packing & export.
Cast Test with Your Production Material
Never approve on water or unpigmented demo resin if you sell colored epoxy or tempered chocolate.
| Material | Test protocol |
|---|---|
| Chocolate | Full temper cycle; demold at shell set |
| Epoxy / UV resin | Production pigment; full cure before demold |
| CP soap | Your fragrance/load; 24-48 hr demold |
| Gummy | Actual Brix/gel system - gelatin vs pectin |
| Wax | Pour temp at high end of range |
Bubbles on resin: resin bubbles. Hardness on chocolate: Shore A for chocolate.
Visual, Flash & Surface Finish
- Finish match - compare to signed photo under neutral light. Matte vs gloss.
- Pinholes - reject gloss resin samples with floor pits (degas failure).
- Parting flash - thin flash acceptable if trimmed; raised lip on food face is not.
- Shore A feel - durometer spot check if quoted Shore A 30 vs 40 matters for your line.
Defect catalog: common defects.
Sign-Off Process & PO Lock
- Complete checklist; photograph fails with scale reference.
- Email written approval: PO number, CAD revision, date, "approve for MOQ 50 production."
- Any change after sign-off - new revision, possible re-prototype 3-7 days.
- Production lead ~2-4 weeks after approval. Lead time.
Keep one approved sample tray sealed as golden master for reorder QC.
When to Revise vs Approve
| Issue | Action |
|---|---|
| Dimension out of agreed tolerance | Revise CAD - re-prototype |
| Logo incomplete fill | Shallow emboss or widen stroke - revise |
| Demold tear on flex | More draft, Shore A, or spacing - revise |
| Minor flash on lip | Trim on production if sample shows trim path OK |
| Cast sticks - operator timing | Retest process before blaming mold |
Quote changes: compare quotes. Brief: manufacturer brief.
Frequently Asked Questions
Can I approve from photos only?
Not recommended - dimensions and demold force need hands-on check.
Sample cavity count vs production?
Geometry matches; density validated in CAD - approve layout drawing too.
Who pays re-prototype?
Supplier if process error; buyer if CAD/ spec change after approval.
MOQ after approval?
MOQ 50 locked to signed revision.
Expedite production after fast approval?
Possible - confirm slot on approval email.
Food docs at sample stage?
Request FDA/LFGB summary with production PO if selling food. FDA vs LFGB.
Contact for approval?
[email protected] | Contact RUUIPON | WhatsApp +86 135 3006 2969.
Ready to order custom silicone molds?
Free quote for OEM/ODM projects. MOQ 20 · Prototype 3-7 days · FDA/LFGB available.