CNC Cutting

Check glass sizes, hole and cutout locations, edge chipping, tool condition and cleanliness. Worn CNC tools may be the cause of these tiny edges’ constant flaws, which can lead to cracking.

Sharpening the edges

• Evaluate the strength and maintain uniform chamfer size, edge roughness, and polishing. Proper polishing increases edge durability and eliminates cutting damage.

Chemical Hardening

• The KNO₃ bath temperature, strengthening time, surface CS, DOL, CT, and flatness should all be monitored. Stress meters are required since visual inspection is not enough to confirm the quality of strengthening.

AF Coating

• Verify the coating thickness, water contact angle, curing temperature and duration, and abrasion resistance to ensure consistent performance.

3. Evaluation of Performance

Visual inspection is not enough to confirm product functionality, hence each OEM batch must be thoroughly tested. Impact Resistance: Examine the center, corners, and edges using ball-drop tests. Surface Hardness: Use the 9H pencil hardness test, which measures scratch resistance instead of impact strength or adhesive properties. To assess AF durability, measure the water contact angle both prior to and during controlled abrasion. Optical Performance: Assess light transmittance, yellowness, reflectance, and haze. Reliability Testing: Use thermal cycling, humidity, low-temperature, thermal shock, and UV testing to detect cracking, bubbles, delamination, yellowing, and coating defects.

4. Final Quality Control (FQC)

FQC tests finished protectors before telivery. Check for coating and printing defects, chamfer quality, glue overflow, edge chips, fractures, bubbles, and particles. Verify dimensions, thickness, cutout positions, and flatness.

Fit, alignment, bubble-free adhesion, touch sensitivity, and case compatibility will be tested on actual devices with sample protectors installed. Each batch should have a clear PASS, REWORK, or REJECT decision.

5. Outgoing Quality Control, or OQC

Product models, quantities, packaging, labels, barcodes, carton condition, packing lists, test findings, and shipping marks are all examined by OQC prior to dispatch.

Prior to production, agreement should be reached on AQL sample criteria and acceptance limits for critical, major, and minor errors. For expensive transactions or new suppliers, third-party pre-shipment inspection may provide additional protection.

6. Traceability and QC Records

A professional factory should maintain current IQC, IPQC, FQC, and OQC reports, material CoA/CoC documentation, production records, batch test reports, strengthening bath records, and NCR/CAPA records.

Completed items must be able to be connected to their manufacturing batches and lots of raw materials. Without proper QC records, customers cannot reliably verify the factory’s quality system.

7. What Should an OEM Purchaser Look for?

Don’t rely only on suppliers’ claims. During audits, confirm actual processes and paperwork. Check for rejected product separation, batch traceability, equipment calibration, CNC and polishing controls, stress meters, AF coating tests, lamination conditions, FQC equipment, and material inspection.

Wherever possible, monitor important tests using samples from current manufacturing.

How this runs at MPG: every OEM order passes three inspection stages — incoming material, assembly line and pre-shipment — third-party inspection is always welcome, and any quality issue is covered by free replacement or a refund within six months of collection.

In conclusion

Throughout the whole production process, OEM tempered glass quality control goes beyond the final inspection. IPQC manages production, IQC controls raw materials, FQC inspects finished goods, and OQC verifies delivery.

The best approaches for OEM buyers are to review test findings, verify processes, and look at actual things. A reliable manufacturing facility must have traceable records, qualified inspectors, adequate testing equipment, documented processes, and clear quality standards.

Ultimately, a screen protector’s quality is determined by how reliable it is after installation, shipment, and frequent use.

Contact us for free samples or a QC report review: info@mobilephoneguard.com · WhatsApp +8618102732521

Related reading:

Edge Crush Test for Tempered Glass Screen Protectors

10 Common Quality Problems in Tempered Glass Screen Protector Manufacturing