As a mainstream high-end packaging container widely used in beauty and skincare products, candy and snacks, digital accessories, cultural and creative gifts, and precision small parts storage, the rectangular tin box with window features dual core advantages of a visible window design and premium metal texture. Its forming accuracy, light transmission clarity, compression resistance, durability, food contact safety and long-term storage stability are entirely determined by the strict selection and standardized proportion of raw materials at the source. Different from low-cost general tin boxes on the market that adopt recycled miscellaneous materials, thin iron sheets and low-quality transparent patches, this rectangular tin box with window adopts brand-new original food-grade raw materials throughout the production process. Every type of raw material, including tinplate substrate, transparent window material, auxiliary sealing accessories, surface protective coating and printing ink, undergoes hierarchical selection, special testing and compliance verification, fundamentally avoiding common quality problems such as deformation, yellowing, cracking, delamination, peculiar smell and corrosion. It builds a high-quality metal packaging carrier suitable for high-end retail, cross-border export and brand customization.

　　The core substrate adopts first-grade brand-new original tinplate (tinned steel sheet), which serves as the core foundation material for tin box forming. All raw materials are rolled from large factory original steel billets without doped recycled scrap iron or secondary recycled materials. The substrate thickness is uniform and controllable, with conventional customized thickness ranging from 0.20mm to 0.28mm, which can be flexibly adjusted according to product bearing capacity, stacking storage and transportation, and compression resistance requirements. The original tinplate substrate has a dense metal crystal structure with moderate hardness and excellent toughness. Different from soft thin recycled iron sheets, the formed box body is flat and straight with regular edges and corners, without problems such as uneven local thickness, stretching cracking and corner collapse. The tinned layer on the substrate surface is uniform and delicate with qualified tin coating, no missing plating, pinholes or oxidation spots. It has excellent inherent rust and corrosion resistance, which can resist air oxidation and slight moisture erosion during long-term normal storage, effectively preventing the tin box from blackening, rusting and peeling, and greatly extending the service life of the package. Meanwhile, the original tinplate material has strong plasticity, adapting to precise processes such as regular rectangular cutting, high-precision bending, seamless edge pressing and rounded corner polishing, ensuring flat and burr-free opening of the window position and providing an accurate substrate foundation for subsequent fitting of transparent patches.

　　The core light-transmitting material for the window adopts high-transparency food-grade PET transparent sheet, the key raw material for visible display effect. Abandoning the defects of ordinary PVC and recycled plastic sheets such as easy yellowing, atomization, poor toughness, low-temperature embrittlement and impurity inclusion, it is extruded and formed from brand-new original PET raw materials. The material is pure and impurity-free with a light transmittance of over 92%, delivering a high-definition and transparent window view. It can completely and clearly present the original texture and colors of candies, beauty creams, cultural and creative products, precision accessories inside the box without fuzzy fog or wave deformation. This PET raw material has stable physical properties, excellent tensile, tear and bending resistance. It is not easy to fall off, crack or warp after fitting the tin box window position, adapting to long-distance logistics transportation and repeated use. In addition, the raw material has excellent weather resistance, no deformation or yellowing under high and low temperature environments. It can maintain a long-term high-definition transparent display effect when placed in supermarket shelves and indoor display scenarios. Fully compliant with food contact safety standards, it precipitates no harmful substances and has no peculiar smell, which can be in direct contact with leisure snacks, handmade pastries, candies and other foods, safely adapting to all categories of packaging scenarios.

　　Box body protection and inner wall materials adoptfood-grade environmentally friendly protective coating, specially adapted to the characteristics of metal substrates. As a water-based environmentally friendly resin material, the inner wall coating is benzene-free, heavy metal-free and harmful solvent-free. It has passed food contact safety testing, eliminating the problems of strong peculiar smell, easy precipitation and food corrosion caused by traditional oil-based coatings. The coating has strong adhesion, evenly covering the metal surface of the tin box inner wall to form a dense protective film. It effectively isolates direct contact between metal and packaged products, prevents high-sugar, slightly acidic and oily foods from corroding metal substrates, avoids precipitation of metal components polluting products, and fully guarantees packaging safety. The outer wall protective coating is made of wear-resistant and scratch-resistant environmentally friendly coating raw materials with compact and delicate texture. It can effectively resist scratches and paint peeling caused by daily friction and slight collisions, improve the wear resistance and texture of the tin box surface, and provide a high-quality adhesion base for subsequent processes such as color printing, hot stamping and matte lamination. It makes brand patterns and texts full, delicate and long-lasting without fading.

　　Sealing and auxiliary supporting raw materials are finely screened to adapt to the long-term reuse requirements of tin boxes. The fitting part of the box cover and box body is equipped with a high-elastic environmentally friendly sealing rubber strip, made of food-grade flexible silica gel. It is odorless, non-toxic and harmless, with excellent aging resistance and deformation resistance. It is not easy to harden, crack or fall off after repeated opening and closing and long-term storage. It can effectively improve the box tightness, block dust and moisture intrusion, and keep the internal products dry and clean. All printing processes of the tin box adopt environmentally friendly soybean ink as the core printing material, replacing traditional chemical ink. It features low VOC, no pungent peculiar smell and high color restoration. The printed patterns are clear, three-dimensional and layered, suitable for customized printing of various brand patterns, LOGOs, texts and parameters. With strong adhesion, the ink is not easy to fade or scratch, complying with domestic and foreign environmental protection testing standards and meeting cross-border export compliance requirements. In addition, flexible polishing auxiliary materials are used for edge polishing of the tin box, leaving no hard particle residues, ensuring smooth and burr-free edges of finished products, and avoiding hand scratches and product damage during use.

　　All raw materials implement strict source quality control and compliance testing to build a full-link quality assurance system. Each batch of tinplate substrate is attached with material inspection reports and tin plating compliance certificates to eliminate inferior recycled materials; each batch of PET transparent sheets is sampled and tested for light transmittance, toughness and food contact safety; protective coatings, printing inks and sealing rubber strips are all selected from compliant large factory raw materials with full traceability and detectability. Strict control is implemented in every link from raw material procurement, warehousing sampling inspection, production adaptation to finished product verification, putting an end to the industry chaos of adulteration and shoddy substitution. Relying on the advantages of high-quality original raw materials, this rectangular tin box with window integrates high-definition display, sturdiness and durability, safety and environmental protection, long-term rust prevention and customizable adaptability. It not only meets the safe packaging needs of food, beauty, cultural and creative products, but also improves product brand premium through high-end texture. Meanwhile, it supports repeated recycling and reuse, conforming to the global development trend of low-carbon environmental protection and sustainable packaging, and serves as a preferred high-quality packaging product for commercial customization, retail packaging and gift storage.