Glass looks simple, but consistent quality requires discipline at every stage. Here are the seven checkpoints every order passes in our factory before it is loaded into a container.
1. Raw material inspection
Because we draw our own borosilicate tubes and rods, QC starts at the raw glass stage: diameter tolerance, wall thickness uniformity and visual clarity are checked on every batch.
2. Dimensional check after forming
Capacity, height, diameter and mouth size are measured against the approved drawing. For lids and sealing products, fit tolerance is the critical dimension.
3. Annealing inspection
Proper annealing removes internal stress — the invisible cause of most spontaneous breakage. We verify annealing with polariscopes on a sampling basis.
4. Visual inspection
Every piece is checked for stones, bubbles, scratches and deformation under strong light. Our internal standard is stricter than the industry norm for export products.
5. Decoration adhesion test
Printed and decal logos go through tape tests and dishwasher-cycle tests to make sure the branding survives real use, not just the showroom.
6. Function test
Sealing products are water-tested for leakage; double-wall cups are checked for insulation performance and base stability.
7. Final AQL sampling & packing audit
Before loading, we run AQL sampling on finished cartons and verify packing quantity, carton marking and palletization against the packing list.
We welcome customer QC teams and third-party inspectors (SGS, TÜV, Bureau Veritas) at any stage. Learn more about our factory or request our QC flowchart.
