Material Specifications (L1 / L2 / L3)¶
Version: v1.0
1. Purpose¶
Define required physical, chemical, and functional specifications for core materials L1, L2, L3 to ensure consistent product performance.
2. Scope¶
All incoming PET substrates and coatings used for glucose test strip fabrication.
Environment: Material Preparation Room is ISO-9 classified.
3. Summary Table¶
| Layer | Description | Thickness | Size (Primary) | Key Functional Specs | Storage |
|---|---|---|---|---|---|
| L1 | Base PET substrate | 0.30 mm ±0.02 | 400×420 mm sheets | High temp resistance (140°C 30 min no warp; shrink ≤±0.1 mm), flatness ≤0.1 mm deviation | 20% RH, 18–25°C |
| L2 | Middle PET + double-sided hot melt adhesive | PET 0.10 mm + adhesive | Roll / sheet per die load | Adhesive Side A melt 115°C; Side B melt 130°C; peel strength ≥ defined spec | 20% RH |
| L3 | Cover PET with hydrophilic coating one side | 0.10 mm ±0.01 | Sheets matching L1 | Hydrophilic coating drop angle <1°; uniformity CV<5% | 20% RH |
4. L1 Detailed Specs¶
- Thermal Stability: No discoloration or deformation at 130°C continuous 30 min (tunnel oven 5 min + manual vertical oven 25 min, or tunnel oven 30 min).
- Surface Energy: Compatible with conductive ink adhesion.
- Flatness Test: Place on granite plate; max gap ≤0.1 mm using feeler gauge.
- Cleanliness: Particulate count ≥ ISO Class 8 acceptance (visual sampling).
5. L2 Detailed Specs¶
| Property | Requirement | Test Method |
|---|---|---|
| Adhesive A Activation | 115°C ±2°C | DSC / Melt onset |
| Adhesive B Activation | 130°C ±2°C | DSC / Melt onset |
| Peel Strength (A/B) | ≥ X N/25 mm (define) | 180° peel test |
| Residual Solvent | ≤ regulatory limit | GC headspace |
6. L3 Detailed Specs¶
| Property | Requirement | Test Method |
|---|---|---|
| Hydrophilic Coating Contact Angle | <1° (avg of 5 drops) | Goniometer |
| Coating Uniformity CV | <5% thickness | Microscopy / gravimetric |
| Surface Defects | No streaks >2 mm | Visual 100% |
| Ink Compatibility | No bleed after drying | Accelerated test |
7. Incoming Inspection¶
| Checkpoint | Sample Size | Criteria | Record |
|---|---|---|---|
| Dimensions | 5 per lot | Within tolerance | Incoming log |
| Visual Cleanliness | 100% quick scan | No major defects | Lot photo |
| Coating Angle (L3) | 3 samples | <1° | Lab sheet |
| Adhesive Activation (L2) | 1 composite | Within spec | Lab report |
8. Storage & Handling¶
- Humidity: Maintain 20% RH ±2% using controlled chamber; log hourly.
- Temperature: 18–25°C; avoid direct sunlight.
- FIFO: Apply First-In-First-Out with lot segregation.
- Handling: Nitrile gloves, lint-free; avoid bending corners.
9. Traceability¶
Assign lot codes: Layer code + date + sequence (e.g., L1-20251130-01). QR code applied before or after printing stage for L1 linking defects.
10. Non-Conformance¶
Quarantine material; raise Material NCR form; risk assess impact on in-process lots; disposition (Use-as-is, Rework, Reject) signed by QA + Engineering.
11. Records¶
- Incoming Inspection Log
- Lot Certificate of Conformity (supplier)
- Internal Test Reports (contact angle, adhesion)
Revision History: v1.0 Initial release.