Prototype Approval Checklist Before Ordering Production Molds
Receiving a prototype mold is a critical milestone in your custom mold project. This checklist ensures you validate every aspect before approving productio
Kyler Yang · Founder5 min read
Introduction
Receiving a prototype mold is a critical milestone in your custom mold project. This checklist ensures you validate every aspect before approving production, preventing costly mistakes and ensuring your final molds meet all requirements.
Pre-Testing Preparation
Before You Begin
| Task | Status |
|---|---|
| Review the original requirements specification | ☐ |
| Verify the prototype matches the approved CAD render | ☐ |
| Prepare testing equipment (scale, calipers, test materials) | ☐ |
| Set up your production environment for testing | ☐ |
| Review the mold care and maintenance guide | ☐ |
Dimensional Verification
Cavity Dimensions
| Test | Method | Acceptance Criteria | Status |
|---|---|---|---|
| Cavity depth | Digital calipers or CNC measurement | CAD-locked cavity dimensions from CAD specification | ☐ |
| Cavity width | Digital calipers or CNC measurement | CAD-locked cavity dimensions from CAD specification | ☐ |
| Cavity length | Digital calipers or CNC measurement | CAD-locked cavity dimensions from CAD specification | ☐ |
| Overall tray dimensions | Tape measure or calipers | Matches specification sheet | ☐ |
| Flatness (flood-and-scrape) | Precision level or feeler gauge | ±0.1mm across pour surface | ☐ |
| Alignment pins (two-piece) | Visual and fit test | Proper engagement, no wobble | ☐ |
Surface Finish
| Test | Method | Acceptance Criteria | Status |
|---|---|---|---|
| Visual inspection | Look at cavity surfaces | Smooth, no defects, bubbles, or tears | ☐ |
| Gloss level | Compare to approved sample | Matches specified finish | ☐ |
| Detail reproduction | Inspect logo/text under magnification | Sharp, legible, matches master | ☐ |
| Pour gate quality | Visual inspection | Clean, no flash or overflow | ☐ |
Production Testing
Weight Accuracy Test
Method: 1. Produce 10 test pieces from different cavities 2. Weigh each piece on a calibrated scale (0.01g precision) 3. Calculate average and variation
| Metric | Acceptance Criteria | Your Result | Pass/Fail |
|---|---|---|---|
| Average weight | Matches target weight | _____g | ☐ |
| Weight variation | a job-specific weight band after DFM (CBD/regulated) or ±5% (general) | _____% | ☐ |
| Heaviest piece | Within tolerance | _____g | ☐ |
| Lightest piece | Within tolerance | _____g | ☐ |
Demolding Performance Test
| Test | Method | Acceptance Criteria | Status |
|---|---|---|---|
| Easy release | Remove 10 pieces from different cavities | Clean release, no tearing | ☐ |
| No sticking | Inspect cavities after demolding | No residue or material retention | ☐ |
| Edge quality | Inspect product edges | Clean edges, no dragging or stretching | ☐ |
| Consistency | Test across all cavity types | Uniform demolding performance | ☐ |
Detail Fidelity Test
| Test | Method | Acceptance Criteria | Status |
|---|---|---|---|
| Logo sharpness | Inspect with magnifying glass | Crisp edges, no blurring | ☐ |
| Text legibility | Read embossed text | All characters clear and readable | ☐ |
| Surface texture | Compare to master model | Texture matches expected finish | ☐ |
| Fine detail | Inspect small features | Details reproduced without loss | ☐ |
Equipment Compatibility Test
| Test | Method | Acceptance Criteria | Status |
|---|---|---|---|
| Tray dimensions | Measure against your equipment | Fits properly with adequate clearance | ☐ |
| Depositor spacing | Test with your depositor nozzles | Proper alignment, no interference | ☐ |
| Cooling compatibility | Run test cycle in your cooler | Uniform cooling across all cavities | ☐ |
| Stacking | Stack multiple trays (if applicable) | Stable stacking, no deformation | ☐ |
Production Simulation Test
Full Cycle Test
Run a complete production cycle to validate the mold in real conditions:
| Step | Check | Status |
|---|---|---|
| Material preparation | Verify material temperature and viscosity | ☐ |
| Deposition | Fill all cavities completely | ☐ |
| Scraping (if applicable) | Clean scrape line, no residue | ☐ |
| Cooling | Complete setting within expected time | ☐ |
| Demolding | All pieces release cleanly | ☐ |
| Inspection | No defects in finished pieces | ☐ |
| Cycle time | Meets target cycle time | ☐ |
Output Test
| Metric | Target | Actual | Pass/Fail |
|---|---|---|---|
| Pieces per cycle | _____ | _____ | ☐ |
| Cycle time | _____ min | _____ min | ☐ |
| Output per hour | _____ | _____ | ☐ |
| Defect rate | <2% | _____% | ☐ |
| Weight consistency | a job-specific weight band after DFM | ±_____% | ☐ |
Documentation Verification
| Document | Included? | Notes |
|---|---|---|
| Certificate of Compliance (CoC) | ☐ | Confirms FDA 21 CFR 177.2600 |
| Materials Safety Data Sheet (MSDS) | ☐ | Material composition details |
| Cavity Weight Verification Chart | ☐ | Weight consistency data |
| Care and Maintenance Guide | ☐ | Cleaning and storage instructions |
| Warranty Information | ☐ | Coverage terms and conditions |
| Dimensional inspection report | ☐ | CNC measurement data |
Decision Matrix
All Tests Pass → Approve for Production
If all tests pass acceptance criteria: 1. Sign the prototype approval form 2. Authorize production manufacturing 3. Confirm delivery timeline and shipping details
Some Tests Fail → Request Adjustments
If tests fail: 1. Document each failure with photos and measurements 2. Categorize the issue: - Minor: Can be adjusted on master and re-produced - Major: Requires CAD revision and new master 3. Contact the manufacturer with specific feedback 4. Request revised prototype and repeat testing
Critical Failure → Restart Process
If critical issues are found: 1. Stop approval process 2. Document all issues comprehensively 3. Request meeting with engineering team 4. Determine root cause and correction plan 5. Restart from appropriate phase
Common Prototype Issues and Solutions
| Issue | Likely Cause | Solution |
|---|---|---|
| Weight variation >2% | Cavity depth inconsistency | Request master adjustment and re-production |
| Products sticking | Wrong durometer or insufficient draft | Evaluate durometer change or draft angle adjustment |
| Logo blurry | Master surface finish insufficient | Request polished master and re-production |
| Uneven fill | Pour gate design issue | Request gate redesign and new prototype |
| Tray warping | Insufficient ribbing | Request structural redesign |
| Alignment issues (two-piece) | Pin/socket tolerance | Request revised alignment system |
Approval Checklist Summary
Before Approving, Confirm:
- [ ] All cavity dimensions within CAD-locked cavity dimensions tolerance
- [ ] Weight consistency within a job-specific weight band after DFM (or agreed tolerance)
- [ ] All products demold cleanly without damage
- [ ] Logo and text reproduction is sharp and legible
- [ ] Tray fits your production equipment
- [ ] Cycle time meets production targets
- [ ] Defect rate is below 2%
- [ ] All documentation received and complete
- [ ] No critical issues that would affect production
If Any Item is Not Checked → Do Not Approve
Contact the manufacturer with specific feedback before approving production.
Post-Approval Actions
After prototype approval: 1. Sign and return the approval form 2. Confirm production timeline and shipping details 3. Plan production schedule around mold delivery 4. Train operators on new mold usage and care 5. Archive prototype as reference (don't discard!) 6. Document lessons learned for future orders
FAQ
Q: How many test pieces should I produce for validation? A: Produce at least 10 test pieces from different cavities. For weight accuracy, weigh all 10 and calculate variation. For demolding, test at least 10 different cavities.
Q: What if the prototype weight is slightly off? A: Small variations (under ±1%) may be acceptable. Document the variation and decide if it affects your product requirements. For regulated products (a job-specific weight band after DFM tolerance), even small variations matter.
Q: Can I request changes after approval? A: Changes after prototype approval but before production can usually be accommodated with minimal delay. Changes after production begins may incur additional costs.
Q: Should I keep the prototype mold? A: Yes. Keep the prototype as a reference mold. It can serve as a backup or for future reorders with minor modifications.
Ready to Approve?
If your prototype passes all checks, sign the approval and we'll begin production immediately.
*Published: 2026-08-13 | Category: Production Guide | Read Time: 8 minutes*
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