1. Raw Material Inspection: The Foundation of Quality

Quality begins with materials. Before production, our QI team thoroughly checks all raw materials to avoid risks.

• Stainless Steel Testing: Inner/outer liners use 304/316 stainless steel. We test composition via spectral analysis to meet food-grade standards (FDA, LFGB), preventing harmful substances like lead or cadmium from leaching.

• Plastic Component Check: Lids, seals and handles are BPA-free. We inspect for cracks, deformities and odor, plus a 24-hour 100°C heat resistance test to ensure no warping or toxin release.

• Vacuum Layer Verification: We check liner thickness and ensure no pinholes—even tiny ones ruin insulation.

2. In-Production Inspection: Catching Issues Early

During manufacturing, inline inspections at key stages prevent mass-producing defects.

• Forming and Welding Check: After liner forming, we inspect weld seams for smoothness/strength. Faulty welds cause leaks or poor insulation—we use visual checks and air pressure tests to verify quality.

• Insulation Layer Processing: We monitor vacuum degree with a gauge (higher = better insulation) and check vacuum port sealing to prevent long-term vacuum loss.

• Assembly Inspection: We ensure parts (lid, seal, straw) fit tightly. A loose seal causes heat loss, so we do a 30-minute upside-down water leak test.

3. Finished Product Inspection: The Final Gatekeeper

Fully assembled flasks undergo strict tests to meet performance and safety standards.

• Insulation Performance Test: Core test for flasks. Hot insulation: 95°C water, check temp at 6/12/24hrs. Cold insulation: 0°C ice water, check at 12/24hrs. Only those meeting standards (e.g., ≥60°C after 12hrs for hot drinks) pass.

• Safety and Durability Tests: 1.2m drop test (concrete floor) for impact resistance; steel wool scratch test for paint peeling; 10,000-cycle lid opening/closing test for smooth functionality.

• Visual and Functional Check: Inspect for scratches, dents or uneven paint. Verify lid sealing, unobstructed straw (if included) and accurate temp display (if any).

4. Sampling and Certification: Meeting Global Standards

For consistency, we do 3-5% random batch sampling. Sampled products get stricter tests (48hr insulation, material safety rechecks). Our products also hold FDA (USA), LFGB (EU) and SGS certifications.

We keep detailed QI records. Defects are traced to the source, production adjusted, and retesting done until resolved—this commitment ensures reliable vacuum flask performance.

Next time you use a vacuum flask, remember its meticulous testing. Quality isn’t accidental—it’s the result of every inspection step.