Two Wing Mold owns a full range of precision measuring instruments, from geometrical dimensions to surface roughness. All equipment is regularly calibrated and traceable to national standards.
| Equipment / Tool | Device icon | Application | Accuracy / Capability |
|---|---|---|---|
| CMM (Coordinate Measuring Machine) |  |
Mold bases, complex surfaces, hole pattern position, full FAI of batch parts | 2.8 + L/300μm |
| Manual Vision Measuring System |  |
Planar dimensions, small radii, electrode profiles, quick drawing comparison | (0.003 + L/200)mm |
| Digital Caliper / Micrometer |  |
Quick in-process self-inspection during machining | 0.01 / 0.001mm |
| Height Gauge + Dial Indicator |  |
Parallelism of reference faces, flatness of ejector plate | ±0.01mm |
| Roughness Tester |  |
Mold core surface, cavity finish | Ra 0.05~6.3μm |
| Rockwell Hardness Tester |  |
Verification of heat treatment hardness of mold steel | HRC ±0.5 |
| Screw Test Stand |  |
Performance test of mold springs (gas / coil), insertion/withdrawal force of precision mold components, auxiliary hardness/strength test of mold steel & molded parts, destructive test of small stamping/injection parts | 1000N |
We set inspection points at every key stage to detect anomalies early and intercept them timely.
| Stage | Inspection Content | Equipment | Sampling Plan | Acceptance Criterion |
|---|---|---|---|---|
| 1. IQC (Incoming) | Chemical composition & hardness of mold steel; MFI & moisture of resin | Spectrometer, hardness tester, MFI meter | Once per batch | Compare with material certificate |
| 2. Mold Manufacturing | Critical dimensions & roughness of cavity/core | CMM, roughness tester, screw test stand | 100% per operation | Drawing tolerance |
| 3. Trial Shot (Sample) | First article full dimensions (FAI report) | CMM, micrometer | First shot | Cpk≥1.33 |
| 4. Mass Production (IPQC) | Control chart critical dimensions (every 2 hrs) | Custom gauges, air gauge | 5 pcs / 2 hrs | X̄ ± 3σ |
| 5. OQC (Outgoing) | AQL sampling, full inspection of key dimensions | CMM / vision system | ANSI/ASQ Z1.4 | Accept 0, reject 1 |
| 6. Annual Audit | Mold wear re inspection, MSA of measurement system | CMM、GR&R | Once per year | Equipment calibration valid |
Mold Machining Process Control(From raw material to precision machining)
• Steel: Material certificate (MTC) + hardness spot check (portable hardness tester)
• Mold base: CMM spot check of reference corner squareness and flatness
• First -piece self-check: Caliper/micrometer to confirm key external dimensions
• Patrol inspection: Every 2 hours (focus on critical dimensions, performed by QC)
• Critical feature alert: Dimensions marked with red circle on drawing → when reaching 80% of tolerance band, stop machine for verification
• Electrode: CMM inspection of electrode profile (before first use)
• Spark gap: Test block verification, record discharge parameters
• Post‑machining: CMM re-measurement of key cavity points
• Pilot holes / shaped holes: CMM measurement of position and diameter
• Cut-once, trim-twice (or trim-three times) → surface quality records retained
Key dimension inspection before mold assembly to ensure assembly accuracy, smooth movement, and waterway safety
| Inspection Item | Tool | Acceptance Criterion |
|---|---|---|
| Flatness of mold base reference | Granite surface plate + dial indicator | ≤0.01mm |
| Guide pillar / bush clearance | Inside micrometer + outside micrometer | 0.02 – 0.03 mm clearance |
| Ejector plate smooth movement | Manual push/pull + dial indicator (resistance) | No sticking, full return |
| Cooling circuit integrity | Water pressure test | 0.6 MPa, no leakage |
not full SPC, but control the "vital few"
| Item | Method | Judgment |
|---|---|---|
| Full dimensions | CMM + conventional measuring tools | Compare with drawing |
| Appearance / flash | Visual + magnifier | No defects |
| Assembly / function | Trial assembly / go/no go gauge | Pass |
✅ First article passes → start production
❌ Fails → rework first article after machine adjustment
| Stage | Frequency | Measuring method |
|---|---|---|
| Early production | 1 hour | Caliper/micrometer (3–5 critical dimensions) |
| After stabilization | 2 hours | Same + CMM spot check (1 piece per 8 hours if needed) |
| Shift / material change | within 1 hr | Full dimensions of first article (including CMM) |
Record：Patrol log
• Tolerance ±0.05 mm → Internal limit ±0.03 mm
• Patrol inspection touches internal limit twice consecutively → Stop line for troubleshooting
• troubleshooting direction：mold/machine/material
• Patrol finds out-of-tolerance → Immediately isolate → Trace back all products from last good node to current
• 100% sort or scrap
• Fill Quality Non-conformance Report
• Root cause analysis (5M1E)
Common Secondary Operations & Control Points
| Operation | Common Defects | Control Method | Inspection Tool / Standard |
|---|---|---|---|
| Gate trimming | Protruding nub, depression, stress whitening | Trim flush / punch, residual ≤ 0.2 mm | Visual + feeler gauge / knife edge ruler |
| Deflashing (flash removal) | Flash on parting line, burrs inside holes | Dedicated scraper / deflashing machine; operator self check + QC spot check | Magnifier, feel, go/no-go gauge (for holes) |
| Cleaning / degreasing | Surface oil, mold release residue | Ultrasonic cleaning (aqueous cleaner) → DI rinse → drying | White cloth wipe test, dyne pen for surface energy |
| Assembly (snap / screw / insert) | Broken snap, stripped screw, missing insert | Assembly work instruction + mistake-proofing fixture + first-article check + patrol | Go/no-go gauge, torque wrench, trial assembly |
| Printing / pad printing / laser marking | Misalignment, blurred font, poor adhesion | First article position check → adhesion test (3M tape) → patrol | Caliper / projector for position, ASTM D3359 for adhesion |
| Ultrasonic welding | Weak weld, flash overflow, misalignment | Horn/fixture calibration → first-article pull force test → periodic check | Pull force gauge, cross-section inspection of weld interface |
| Heat treatment (annealing / moisture conditioning) | Dimensional change, distortion | Control temp/time per material spec → spot check dimensions | Oven / humidity chamber, CMM / caliper |
| Packaging | Mix of parts, wrong quantity, incorrect label | Counting scale / auto counter + barcode scan + visual before bagging | Weight check per bag, label vs. part verification |
Standardized homework guidance+full process inspection and control to ensure stable and qualified post-processing processes
Standard: Parting line feels smooth, no sharp burrs; no residual flash inside holes
Tools：Dedicated scraper (adjustable angle), pneumatic deflashing machine, needle files
Inspection：
• Self-check every 10 pieces (feel + visual)
• QC spot check 5 pieces every 2 hours, inspect inside holes with magnifier
Non-conformance：
One missed flash → whole batch returned for rework → record responsible person
First-article validation：
• Weld 10 consecutive pieces, test pull force (≥ customer specification)
• Cross-section 2 pieces, check melt width (≥ 80% of wall thickness)
Patrol：Pull force test on 3 pieces every hour, record data
Machine check：Check horn wear and fixture parallelism per shift
First-article check：
• Position：measure distance from reference datum using caliper or projector
• Adhesion：apply 3M tape and peel off quickly–no peeling
• Abrasion：eraser rub 10 times - no visible blurring
Patrol：Visual check position and clarity on 2 pieces every 30 minutes
Ink management：Record ink batch, curing time, baking temperature(if any)
Ultrasonic cleaning：
• Daily check of concentration, temperature, time
• After drying, white cloth wipe test: no oil, no residue
Dyne pen test：surface energy ≥ 38 dyne
Before packaging：
• Visual check of each part
• Spot check critical dimensions (per AQL standard, typically 0.65/1.5)
Count control：Counting scale or auto counter, error ≤ 0.5%
Label verification：Every carton label matches part (P/N, quantity, date, cavity number),Barcode scanner for double-check
Full process form control+one item, one code traceability, meeting the requirements of factory and customer audits
• CMM Inspection Report (automatically generated, signed for approval)
• First-Article Inspection Report (including CMM data sheet)
• Mass Production Patrol Log (handwritten, authentic traceable)
• Mold Component Self-Inspection Sheet (CNC/EDM/Wire EDM operations)
• Outgoing Inspection Report (final sampling: appearance, dimensions, packaging, label)
Mold：
• Engraving (mold ID, date, steel grade)
Molded part：
• Batch label on each carton
• date, mold ID, cavity number, quantity, inspection stamp
✅ Material certificate (MTC)
✅ CMM full dimensional report (FAI)
✅ Part drawing (signed & stamped)
✅ Hardness report (if required)
✅ Process capability data (CPK, upon customer request)
Standardize the calibration and control of measuring tools, optimize processes for reviewing issues, and steadily improve product quality stability
• All gauges / CMM externally calibrated once a year (third-party metrology institute)
• Internal quarterly comparison: measure same part by different operators / different gauges to verify consistency
• CMM stylus calibrated weekly
Develop corresponding rectification plans for production abnormalities, detection deviations, and customer feedback issues, clarify responsible persons, and optimize production and inspection processes in a closed-loop manner
| Problem Type | Action | Responsible Person |
|---|---|---|
| Repeated out-of-tolerance on same dimension | Analyze (mold wear, machine drift, material variation) → adjust maintenance plan or process | Mold Supervisor + Molding Leader |
| Operator repeatedly misses inspection | Add mistake proof checklist + team leader secondary verification | Quality Supervisor |
| Customer complaint on a specific feature | Upgrade that feature to "critical control point" – inspect every 30 minutes | Project Engineer |
Two Wing Mold is a premier one-stop manufacturer of plastic injection molds and related services, based in ShenZhen, China. With a core leadership team that brings over 20 years of extensive industry experience, we combine deep technical expertise with proven craftsmanship to deliver superior molding solutions.
