Food-grade-gold-lacquered-tinplate, also known as golden lacquered electrolytic tinplate sheet, is a core food packaging metal material widely used for sauce cans, oil tins, biscuit containers and easy-open lids. Its unique food-safe golden lacquer layer isolates metal substrate from acidic, oily food contents, avoiding chemical reaction and rust, while delivering uniform golden inner gloss. This article fully introduces the standardized manufacturing and golden lacquering craft of food-grade-gold-lacquered-tinplate for reference by packaging buyers and metal manufacturers.
Raw material screening is the first critical step for qualified food-grade-gold-lacquered-tinplate. Factories adopt MR-grade electrolytic tinplate (ETP) as base material, with strictly controlled tin coating thickness and clean surface free of oil residue and oxide spots. All raw tinplate coils pass food contact safety inspection to lay a foundation for stable gold lacquer adhesion. Then comes surface pretreatment: continuous alkaline cleaning, water rinsing and high-temperature drying remove surface impurities, followed by passivation treatment to enhance the binding force between tin layer and golden food-grade lacquer, preventing coating peeling during later stamping and curling.
The core golden lacquering procedure determines the quality of food-grade-gold-lacquered-tinplate. Adopt roller coating technology for even gold epoxy lacquer spreading; the food-safe golden paint complies with global food migration standards, BPA-free and resistant to high-temperature retort sterilization at 121℃. Coating weight is precisely controlled at 4–8g per square meter to balance barrier performance and forming flexibility. After uniform coating, semi-finished tinplate enters segmented curing oven, heated gradually under 180–205℃ to fully crosslink the golden lacquer film without damaging the tin substrate.
Post-curing cooling and multi-dimensional quality testing follow immediately. Cooled food-grade-gold-lacquered-tinplate undergoes cross-hatch adhesion test, salt spray corrosion test and food soaking migration detection. Automatic visual inspection eliminates color difference, pinholes and uneven coating defects. Qualified products are cut into standard tinplate sheets or kept as lacquered coils, packed and delivered for can production.
Strict full-process control makes food-grade-gold-lacquered-tinplate possess excellent corrosion resistance, heat resistance and moldability. The food-grade golden lacquer layer solves metal discoloration and flavor contamination problems, becoming the preferred inner coating material for high-end food metal packaging worldwide.
