Coating standard: new specification for coating of inner wall of food packaging barrel for export in China -- gb9686-88 hygienic standard for polyamide epoxy resin coating of inner wall of food containers

Core tip: in the international market, many food and agricultural products are packaged in steel drums, and the hygienic requirements of the inner wall coating have attracted wide attention of all countries In order to meet the needs of the international market, China has also made specific regulations on the hygienic requirements of the inner wall coating of packaging barrels for exported food and agricultural products According to the regulations, the food grade coatings allowed to be used on the inner wall of the packaging barrel include polyamide coating, perchloroethylene coating, organic fluorine coating, etc Polyamide epoxy coating belongs to epoxy coating, and epoxy coating belongs to curing film coating Epoxy resin is generally polymerized by bisphenol A (diphenylpropane) and epichlorohydrin Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Coating House News: in the international market, many food and agricultural products are packaged in steel drums, and the hygienic requirements of the inner wall coating have attracted wide attention of all countries In order to meet the needs of the international market, China has also made specific regulations on the hygienic requirements of the inner wall coating of packaging barrels for exported food and agricultural products According to the regulations, the food grade coatings allowed to be used on the inner wall of the packaging barrel include polyamide coating, perchloroethylene coating, organic fluorine coating, etc Polyamide epoxy coating belongs to epoxy coating, and epoxy coating belongs to curing film coating Epoxy resin is generally made by polymerization of bisphenol A (diphenylpropane) and epichlorohydrin According to the degree of polymerization, the molecular weight of epoxy resin is also different From the perspective of health, the larger the molecular weight (i.e the smaller the epoxy value), the more stable it is, the less likely it is for harmful substances to dissolve and migrate into food, so the higher its safety Polyamide, as the curing agent of polyamide epoxy resin coating, is a kind of high polymer compound, and no toxic report has been found It is reported that the quality (epoxy value) of polyamide epoxy resin is closely related to the ratio of curing agent and curing degree If the ratio of curing agent is appropriate, the higher the curing degree is, the less the uncured substance will migrate to food According to gb9686-88 hygienic standard for polyamide epoxy coating on the inner wall of food containers, the evaporation residue of polyamide epoxy coating in various solvents shall be controlled below 30mg / L Modified anhydrous calcium sulfate whisker modified plastic raw material aromatics solvent oil fertilizer polyurethane iron oxide red ethylene glycol carbonate isocyanate titanium dioxide rubidium aluminum hydroxide perchloroethylene paint with perchloroethylene resin as raw material With plasticizer, the inner wall of the packaging barrel is painted and sprayed to form a film naturally Perchloroethylene coating is generally divided into primer and finish Perchloroethylene resin contains perchloroethylene monomer, which is a carcinogenic toxic compound The perchloroethylene coating after film forming may still contain the residual of vinyl chloride The residual of vinyl chloride monomer in the perchloroethylene coating after film forming shall be controlled below 1 mg / kg according to gb7105-86 hygienic standard for perchloroethylene inner wall coating of food containers Plasticizers, solvents and other additives used in perchloroethylene paint must comply with the relevant provisions of gb9685-94 hygienic standard for the use of additives for food containers and packaging barrels, and toxic or highly toxic additives shall not be used The coating shall be uniform without bubbles, spots, wrinkles and falling off Organic fluorine coatings include polyfluoroethylene, polytetrafluoroethylene and polyhexafluoropropylene coatings These coatings are polymerized with fluorine ethylene, tetrafluoroethylene and hexafluoropropylene as main raw materials, and are sprayed on the inner wall surface of the packaging barrel with certain additives Organic fluorine coating has the characteristics of anti adhesion and anti-corrosion, but its acid resistance is poor, so it is widely used in the steel barrel containing honey inner coating packaging barrel According to experts, in terms of application, the organic fluorine coating on the inner honey packing barrel steel barrel is polytetrafluoroethylene, referred to as PVF coating for short It is a kind of high molecular compound with stable chemical properties, and generally there is no monomer residue It is a relatively safe coating for the inner wall of food packaging barrel According to experts, but when cleaning the inner wall of the drum, most of the current drum manufacturers use spray cleaning and drying line for cleaning The cleaning agent is usually chromate, which may cause the chromate to remain on the surface of the container and then mix into the inner wall coating Therefore, in the production of inner wall honey packaging barrels, the inner wall honey packaging barrels should be inspected according to gb1167-89 hygienic standard for polytetrafluoroethylene coating on the inner wall of food containers The standard stipulates that the appropriate amount of chromium and fluorine shall be controlled between 0.01 mg / L and 0.2 mg / L respectively In addition, when polytetrafluoroethylene is baked, if the temperature reaches 280 ℃, it will fission and produce toxic fluoride with strong volatility Therefore, when using the honey packaging barrel with inner wall of polytetrafluoroethylene, the baking temperature shall not exceed 250 ℃ Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,