Personalized lunch tin box, as an exclusive lunch carrier for daily commuting, campus and office scenarios, takes "food-grade safety, durability, outstanding texture and customizable adaptation" as its core material concept. It closely fits the core needs of lunch storage such as "non-toxic safety, leak-proof and anti-scald, easy to clean, portable and durable", taking into account practicality and personalization, and breaking the shortcomings of ordinary lunch boxes such as "inferior materials, easy deformation, non-leak-proof and odorous". From the box body substrate, sealing accessories, customized process materials to detailed auxiliary materials, every material of this product has undergone strict selection and quality inspection, adhering to food-grade safety standards, integrating durability and personalization needs, and selecting high-cost-performance and high-adaptability high-quality materials. It not only comprehensively protects the freshness and safety of lunch, but also highlights the exclusive style through customized materials, adapting to students, office workers, outdoor enthusiasts and other groups of people. It interprets the lunch box aesthetics of "both practical and personalized" with ingenious materials, and becomes an ideal choice for daily lunch carrying.

　　1. Core Substrate Materials: Food-grade High-end Metal, Safe and Durable, Balancing Texture and Practicality. The substrate is the core of the lunch box, which directly determines the safety, durability and use experience of the product. This product abandons the inferior iron sheet, recycled plastic and other materials of ordinary lunch boxes, and selects two kinds of food-grade high-end metal substrates, which can be flexibly selected according to needs, taking into account the use scenarios and budget needs of different groups of people. All substrates strictly comply with the GB 4806.9-2016 standard for metal materials and products in contact with food, and also meet the international dual certification of FDA and ROHS. They are lead-free, mercury-free, free of harmful heavy metals and any peculiar smell, and can be directly in contact with various foods such as rice, vegetables and meat, preventing the reaction between materials and food, and firmly protecting food safety.

　　The first core substrate is food-grade 304 stainless steel. As the mainstream high-end lunch box substrate, it selects 304 stainless steel raw materials with a purity of up to 99.9%, which have undergone multiple cold rolling and annealing processes, with dense texture and outstanding toughness. The thickness is controlled at 0.4-0.5mm, which not only ensures the sturdiness of the box body, but also is not too heavy. The weight of a single box is controlled at 150-280g (depending on the size), which is portable and burden-free. This material has excellent corrosion resistance, oxidation resistance and high temperature resistance, and can withstand a temperature range of -20℃ to 120℃, adapting to various scenarios such as refrigeration, microwave heating (in non-sealed state) and boiling water disinfection. It is not easy to rust or deform in daily use, and even if it is in long-term contact with acidic and alkaline foods (such as vinegar and pickles), it will not corrode or slag. The service life is more than 5 years, and the durability is far superior to that of ordinary iron sheet lunch boxes. The surface is treated with fine wire drawing process, with a delicate and smooth touch, no granularity or sharp edges and corners, not easy to be stained with oil and food residues, easy to clean, and can be restored to clean with a light wipe.

　　The second core substrate is food-grade tinplate. It selects high-purity cold-rolled steel plate as the base, and the surface adopts food-grade tin plating process. The thickness of the tin plating layer is controlled at 0.08-0.1mm, which evenly covers the surface of the substrate, retaining the sturdiness of the steel plate and improving the safety and texture. The tin plating layer is non-toxic, odorless and corrosion-resistant, can be directly in contact with food, and has good sealing and moisture-proof performance, which can effectively isolate air and moisture, prevent lunch from oxidizing and deteriorating, and extend the fresh-keeping time. The thickness of this material is controlled at 0.35-0.4mm, with light weight (120-250g per box), adapting to daily portable scenarios. The surface can be adapted to various customization processes, which is convenient for printing patterns and texts to highlight personalization. At the same time, it is polished, with a smooth touch, no burrs or defects, balancing practicality and appearance, with outstanding cost performance, suitable for daily use by students and office workers.

　　2. Sealing and Leak-proof Materials: Food-grade Silicone + Reinforced Hardware, Leak-proof and Moisture-proof, Protecting Lunch Cleanliness. The sealing and leak-proof performance of the lunch box depends on the materials of the sealing accessories. This product specially selects high-end food-grade accessories to create a double-layer sealing and leak-proof structure, which comprehensively prevents lunch soup from leaking, avoids polluting bags and clothes, and isolates air to protect lunch freshness. As the core sealing component, the sealing rubber ring is made of food-grade medical-grade silicone material, which is different from ordinary inferior silicone. This material has high elasticity and high density, no odor, non-toxic and harmless. After high-temperature vulcanization process, it is high-temperature resistant and low-temperature resistant, can withstand a temperature of -30℃ to 150℃, not easy to age, deform or fall off, and can still maintain good elasticity and sealing after long-term use.

　　The silicone sealing rubber ring is accurately embedded in the groove of the box mouth, fitting seamlessly with the box cover without any gaps, which can effectively block the leakage of soup and water stains. Even if it is filled with soup noodles, porridge, sauce and other soup-containing foods, it will not leak when inverted or shaken, adapting to portable scenarios. The surface of the sealing rubber ring is matte treated, not easy to be stained with oil, easy to clean, detachable for cleaning, avoiding bacterial growth and ensuring food hygiene. In addition to the sealing rubber ring, the snap is made of high-quality zinc alloy material, which has been rust-proof and corrosion-proof treated, with hard texture, not easy to break or rust. The locking force is moderate, and the box cover is firmly fixed after closing, further strengthening the sealing effect. At the same time, it is smooth to open and close, and can be operated with one hand, adapting to daily use scenarios. The surface of the snap is finely polished, smooth to the touch, no sharp edges and corners, avoiding scratching hands, balancing practicality and safety.

　　3. Customized Process Materials: Environmentally Friendly and Durable, Highlight Personalization, Adapt to Diverse Customization Needs. The core advantage of the personalized lunch box lies in customization. This product selects environmentally friendly, durable and easy-to-color customized process materials, taking into account personalization and practicality. It can print patterns, texts, logos, etc. according to needs, adapting to personal customization, enterprise customization, campus customization and other scenarios. All customized materials meet environmental protection standards, no harmful volatiles, no odor, do not affect food safety, and are not easy to fade or fall off, and can still maintain a clear and complete customization effect after long-term use.

　　Surface customization mainly adopts three processes: environmentally friendly silk screen printing, laser engraving and gold stamping, combined with corresponding high-quality materials: environmentally friendly silk screen printing uses food-grade environmentally friendly ink, lead-free and benzene-free, with bright color and strong adhesion, which can print a variety of colors and complex patterns, adapting to various styles such as cartoon, simple and personalized. The silk screen layer is treated with high-temperature curing, not easy to scratch or fade, and the ink will not fall off when wiped daily or in contact with food; laser engraving uses high-end laser engraving equipment, no additional ink is needed, and the engraving effect is presented relying on the texture of the substrate itself, with clear and three-dimensional lines, not easy to wear, adapting to the customization of texts and simple patterns, highlighting a simple and high-grade sense, and at the same time not damaging the surface of the substrate, not affecting the use safety; gold stamping process uses food-grade environmentally friendly gold stamping paper, with full color and outstanding texture, adapting to the hot stamping of logos and texts, improving the product style. The gold stamping layer is reinforced, not easy to fall off or oxidize, and can still maintain a bright luster after long-term use. In addition, the customized area can use environmentally friendly film covering materials. The transparent film is thin, non-toxic and odorless, which can protect the customized patterns, prevent scratching and fading, and does not affect the touch and appearance.

　　4. Layered Separation Materials: Food-grade Materials, Safe and Convenient, Adapt to Diverse Lunch Collocations. To meet the lunch collocation needs of different groups of people, this product is equipped with a layered separation design. All layered and separation materials are food-grade materials, consistent with the core substrate materials (304 stainless steel or tinplate), no any odor, non-toxic and harmless, can be directly in contact with food, and at the same time take into account sturdiness and convenience. The layered partition is made of the same food-grade metal material as the box body, with a thickness of 0.3-0.35mm, tough texture, not easy to deform, can be flexibly disassembled and installed, and is convenient to adjust the number of layers according to the amount of lunch, adapting to different needs such as single-person meals and double-person meals.

　　The edge of the partition is polished with multiple rounded corners, with a polishing accuracy controlled within 0.01mm, round and smooth, no sharp protrusions, avoiding scratching hands and the box body, and fitting the inner wall of the box body, seamless connection, preventing different foods from tasting and leaking, and protecting the original taste of lunch. Some styles are equipped with food-grade silicone separation strips, made of the same medical-grade silicone material as the sealing rubber ring, high elasticity, non-toxic and odorless, which can flexibly adjust the separation space according to the size of food, adapting to the classified storage of various foods such as rice, vegetables, meat and fruits, and at the same time easy to clean, detachable for cleaning, avoiding bacterial growth caused by food residues. The layered box cover uses the same material and sealing materials as the main box cover, with independent sealing, further improving the leak-proof and fresh-keeping performance, adapting to various lunch collocation scenarios.

　　5. Detailed Auxiliary Materials: Ingeniously Selected, Improve Experience, Balance Safety and Convenience. This product focuses on the polishing of every detailed material. From the handle, non-slip pad to the inner wall coating, every auxiliary material has been strictly selected, taking into account safety, practicality and use experience, making daily use more convenient and assured. As the core portable component, the handle selects two kinds of high-quality materials, which can be flexibly selected: the first is food-grade silicone handle, soft and delicate, non-slip and anti-scald, comfortable to touch, can withstand high temperature, avoid being scalded when holding, and has good toughness, not easy to break or age. The handle is connected with the box body by seamless connection technology, firm and durable, easy to carry; the second is metal handle, made of the same food-grade metal material as the box body, after fine polishing and rust-proof treatment, hard texture, not easy to deform, smooth surface, heavy hand feel, adapting to simple and high-end use needs, foldable design, saving space, easy to store and carry.

　　The bottom of the box body is equipped with a high-end silicone non-slip pad, made of food-grade silicone material with high elasticity and excellent non-slip performance, non-toxic and odorless, not easy to age, fitting the bottom of the box body. When placed on desktops, office desks, car platforms and other positions, it is not easy to slide, avoiding accidental falling, and at the same time protecting the bottom of the box body, preventing wear and scratching, extending the service life. The inner wall of the box body is coated with food-grade epoxy polyester coating, non-toxic, odorless, delicate and smooth, only used for lunch boxes made of tinplate, which can further improve corrosion resistance and anti-sticking performance, avoid food sticking to the box wall, facilitate cleaning, and prevent metal materials from directly contacting food, double protecting food safety; the coating is treated with high-temperature curing, not easy to fall off or scratch, and can still maintain smooth and clean after long-term use, without affecting food safety and use experience.

　　6. Material Quality Assurance: Strict Inspection, Continuous Improvement, Ensure Long-term Durability. All materials of this product have undergone multiple quality inspections. From raw material procurement to finished product delivery, every link is strictly controlled to ensure that the materials are safe, durable and environmentally friendly. Raw materials are purchased from regular manufacturers' food-grade materials, with relevant inspection reports, eliminating inferior materials and recycled materials; during the production process, the substrate, sealing rubber ring, customized materials, etc. are inspected one by one to check for odor, defects, harmful substance residues and other problems; before the finished product leaves the factory, multiple inspections such as sealing performance, high temperature resistance, corrosion resistance and durability are carried out to ensure that the product meets food-grade safety standards and has no potential safety hazards in long-term use.

　　All materials have good compatibility. Combined with exquisite production technology, it ensures that the box body, snap, partition, handle and other components are closely connected, not easy to loose or break, and the service life is far higher than the industry average; the customized materials are closely combined with the substrate, not easy to fade or fall off, balancing personalization and durability; the auxiliary materials are all environmentally friendly, non-toxic and durable materials, comprehensively improving the use experience, and at the same time conforming to the concept of green environmental protection, can be reused, avoiding resource waste. Whether it is carried for daily commuting, or used for a long time on campus or in the office, the high-quality materials of this product can always maintain good performance, protect food safety, highlight personalized style, and create a practical, safe and personalized personalized lunch tin box with ingenious materials.