Glass Cleaning
Glass Inspection and Test
Dehumidification of Finished glass
Must-Have Process Requirements
Large-size cover glass (mainstream thickness 1.86 mm, up to 812 mm) is completely different from small-size mobile glass. The core focus is large-area flatness + heavy-duty processing + physical tempering.
● Substrate: Prefer ultra-clear float soda-lime glass (light transmittance ≥91%). High-end uses high-alumina float or overflow glass (Corning Gorilla / AGC Dragontrail / Panda). Must provide original manufacturer COA certificate.
● Cutting & Slitting: Large-format automatic cutting table (supports 3.3 m × 2.4 m+ mother sheets), mainly diamond-wheel straight cutting, tolerance ±0.3 mm, edge chipping <100 μm. Few special shapes/holes, but must support camera holes and rounded corners.
● CNC Edge Grinding / Drilling / Chamfering: Heavy-duty large CNC or dedicated edging lines capable of handling >2 m lengths; edges polished to mirror finish or 2.5D/3D arc (for premium requests).
● Grinding & Polishing: Large double-side polishing machines; thickness uniformity ±0.05 mm, no waves or orange peel across the entire area (the most common failure point for large sizes).
● Tempering (Strengthening): Mainstream: Physical tempering (680°C high temperature + rapid cooling, surface stress >100 MPa), suitable for ≥3 mm thickness; can be synchronized with ceramic ink printing (excellent weather resistance, suitable for outdoor use). High-end thin glass: Chemical strengthening (rare for very large sizes due to huge salt bath furnaces and warpage control challenges; higher cost). Post-tempering flatness must be <0.1 mm/m; require stress-meter test reports.
● Silk-Screen / Printing: Large-format ceramic ink screen printers for black borders/LOGO/function areas; high-temperature curing synchronized with physical tempering; registration error <0.2 mm.
● Coating: Large vacuum magnetron sputtering lines for AR (anti-reflective≥98%), AF (anti-fingerprint), AG (anti-glare). Must pass adhesion tests (tape test / cross-hatch).
● Cleaning + 100% Inspection: Class 1000+ cleanroom line + AOI automatic optical inspection + laser scanning + manual check. 100% optical distortion inspection required (large panels must not show “funhouse mirror” effect).
● Packaging & Shipping: Heavy-duty wooden crates + suction-cup fixing + EPE pearl cotton + shock airbags. Single piece weight can reach 50–100 kg; professional heavy-cargo logistics required.
Pros & Cons Sourcing from China
Advantages
● Extremely competitive pricing: Same-spec European/Japanese/Korean factories cost 3060% more. Chinese factories have fully localized mature equipment, giving you 1525% margin room.
● Strong customization capability: Supports ultra-large sizes (up to 100 inch+), special arc edges, outdoor-grade ceramic ink, multi-layer coatings (AG+AR+AF). MOQ as low as 10~200 pcs negotiable.
● Lead time & scale: Mature factories offer 5,00020,000 m² monthly capacity; standard lead time 45~60 days, can be compressed to 35 days for volume orders.
● Complete supply chain: Local glass substrates (Xinyi, CSG), equipment (Beibo, Yinhua), coating consumables — all stable and cost-effective.
● Rich export experience: Many factories already hold EU CE, RoHS, REACH, ISO9001, IATF16949 certifications and understand fumigated wooden crates, marine insurance, etc.
Disadvantages (Risks You Must Mitigate in Advance)
● High equipment barrier → few real players, quality varies: Nationwide, fewer than 50 factories can truly handle 85-inch. Many small workshops claim “any size” but only have 55-inch equipment; forcing larger sizes causes sharp rise in warpage and breakage.
● Extremely high breakage risk: One piece damaged during tempering, handling or ocean transport can cost thousands of RMB; you bear insurance and rework expenses.
● Difficult flatness & optical uniformity control: Large-area tempering easily causes warpage; uneven coating leads to “rainbow patterns” and high end-customer return rates.
● Lead-time fluctuations: If a large tempering furnace or coating chamber fails, delays of 30~60 days are common.
Red Flags (Pass Immediately)
● Website only shows mobile small-size photos and claims ”any size possible”
● No photos/videos of large equipment
● Price 30%+ below market
● Factory located outside glass industry clusters (Dongguan/Shenzhen/Heyuan)