As early as the 1950s, the US FDA required to attach great importance to the detection of food and agricultural product packaging barrels. In order to meet the needs of the international market, China has also made specific provisions for the export of food, agricultural packaging barrel coating. According to the regulations, it is allowed to use food-grade coatings on the inner wall of packaging drums, mainly epoxy/polyamide coatings, and perchloroethylene coatings, organic fluorine coatings, etc. At present, China's inner coating steel drums for food and agricultural products include honey buckets, juice buckets, ketchup buckets, etc. If used for the inner coating of interior coating drums for these foods, the sanitary quality cannot meet the safety and hygiene requirements. It will cause secondary pollution to food.
Epoxy/polyamide coatings are epoxy resin coatings, while epoxy resin coatings are cured film forming coatings. According to the provisions of GB9686-88 “Sanitary Standards for Polyamide Epoxy Resin Coatings on Inner Walls of Food Containersâ€, the evaporation residue of polyamide epoxy coating in various solvents should be controlled below 30mg/l.
Perchloroethylene paint uses vinyl chloride resin as raw material, together with plasticizer, and is naturally dried and filmed after being painted or sprayed on the inner wall of the packaging drum.
The organic fluorine coating has the characteristics of anti-sticking and corrosion resistance, but its acid resistance is poor, so it is widely used in inner coating steel drums containing honey.
At present, most of the packaging drum manufacturers use the spray cleaning and drying lines to clean the inner wall of the steel drums of the packaging drums. Chromate is commonly used as a cleaning agent, which may cause chromium salts to remain on the surface of the container and then mix in the paint. Therefore, in the production of honey coated steel drum, should be in accordance with GB1167-89 "food container PTFE coating the inner wall of the health standards," the inner coating of honey coated steel drums for inspection. The standard states that the appropriate amount of chromium and fluorine should be controlled at 0.01 mg/l and 0.2 mg/l, respectively.
In addition, when PTFE is baked, fission occurs when the temperature reaches 280°C, resulting in highly volatile toxic fluorides. Therefore, in the use of PTFE coated honey drums, the general baking temperature must not exceed 250 °C.
In recent years, fruit juices, ketchup, honey, etc. exported by China have often been returned due to excessive pesticide residues. As food packaging barrels, the residual amount of paint solvent on the inner wall should be well controlled. In the production of food packaging barrels must be in accordance with food safety requirements to ensure that the food barrel cleaning and paint use in line with relevant requirements. To this end, a chain of supervision systems should be formed, the use of food packaging barrels should be requested from the packaging barrel manufacturers for food hygiene inspection report of the packaging barrels; packaging barrels production companies should obtain coating food suppliers from the interior coating of the food safety and health Inspection Report. At the same time, relevant departments should also regularly supervise and inspect food packaging drums and issue inspection reports.