Square Mint Tin Box Bulk, with strict quality inspection as the core, adheres to the quality consistency of mass production and establishes a full-process, multi-dimensional quality inspection system. Each tin box undergoes layers of screening and strict testing to prevent unqualified products from entering the market. With stable quality performance, it becomes a reassuring choice for bulk purchase, food packaging and gift customization. The entire mass production follows the principle of "full-staff quality inspection, full-process control and full compliance", and builds six core quality inspection links from raw material entry to finished product delivery to ensure that each batch and each product meets quality standards, balancing mass efficiency and quality stability.

　　The first quality inspection is raw material entry inspection. High-purity food-grade tinplate is selected, and each batch of raw materials must provide a material test report, focusing on testing indicators such as iron content, tin plating thickness and heavy metal content. The iron content is ≥99.7%, the tin plating thickness is ≥0.02mm, and the content of harmful heavy metals such as lead and chromium is ≤0.001mg/kg, complying with the national standard GB 4806.9-2016 for metal materials for food contact. Unqualified raw materials are rejected to control quality from the source, and the flatness of the raw material surface is tested to ensure no impurities or scratches and smooth subsequent processing.

　　The second to fourth are production process quality inspections, covering three core processes: stamping forming, surface treatment and assembly. After stamping forming, inspectors test the squareness of the box body and the roundness of edges and corners one by one, with dimensional error controlled within ±0.01cm, no unevenness, wrinkles or burrs; After surface treatment, test the color uniformity and printing clarity, no color overflow, color difference or ink loss. For frosted models, test the delicate touch, and for bright models, test the gloss to ensure uniform appearance quality; In the assembly link, focus on testing the fit between the box cover and the box body and the smoothness of opening and closing. Bulk tin boxes must ensure uniform size and shape, no looseness or jamming, and consistent use experience.

　　The fifth and sixth are finished product full inspection and delivery sampling inspection. The finished products adopt 100% full inspection mode, testing four core indicators: appearance, size, sealing performance and durability. The sealing performance must ensure that the water vapor transmission rate is ≤0.1g/(m²·24h), and the durability must bear 300N vertical pressure without deformation and fall 1m without damage; Delivery sampling adopts random sampling, with 5% samples selected from each batch for re-inspection to ensure stable bulk quality. At the same time, the packaging of bulk products is inspected to ensure it is intact and undamaged, facilitating storage and transportation. The entire quality inspection system is strict and detailed, safeguarding bulk quality through full-process control and building the core competitiveness of products.