The gold aluminum sheet is one of the popular colors of the aluminum foil for bottle cap. It is a product after deep processing of the surface of aluminum sheet, which can greatly improve the weather resistance and corrosion resistance of aluminum sheet. In the field of food packaging, color-coated aluminum is mainly used in food cans, can lids, bottle caps, box lids, pull rings, food boxes, etc
The color coated aluminum sheet for bottle cap is mainly pre-coated with paint or pre-coated with DOS oil on the aluminum base material, mainly using sheet coating and roller coating processes. Sheet coating means that DOS pretreatment is carried out first, and then sheet coating is carried out after cross-shear cutting; roller coating means that DOS treatment is not required, and roller coating is carried out directly on the surface of the aluminum substrate after cleaning, directly used or after cross-shear cutting.
At present, the pretreatment process of the domestic aluminum sheet roller coating production line is integrated into the production line continuously with paint coating and paint curing. Such a production line has continuous production, fast speed, high output, high efficiency and easy quality control. However, the investment in equipment is large and the degree of automation is high.
Generally, the continuous aluminum sheet coating production line adopts two degreasing spraying or non-rinsing roller coating chemical conversion liquid or both spraying and non-rinsing roller coating process, aluminum sheet roller coating pre-coating and aluminum coil roller coating before painting is the same.
There are three heating methods for aluminum sheet coating curing: air bath convection heating, radiation heating and NIR (near infrared curing).
Hot air circulation curing is a method of heating and curing aluminum sheet coatings by applying the principle of convective heat transfer. It uses hot air as a heat carrier to transfer heat to the aluminum sheet coating by convection, so that the coating is cured. It is characterized by uniform heating, high precision temperature control, easy control, suitable for volatilization of solvents and curing rate of coating resin melting or polymerization reaction film formation. It is an ideal curing method with high requirements for coating quality.
The temperature of the aluminum plate coming out of the curing furnace is relatively high, and the temperature needs to be lowered to below 50°C to cool, harden and shape the coating film, so as not to cause surface defects such as pressure spots, adhesion, scratches, and paint drop. There are two cooling methods for aluminum sheets: air cooling and water cooling.
Haomei Aluminum is a big aluminum foil sheet manufacturer. We have complete specification of aluminum foil for pet jar. Welcome to leave message below to inquire what you need.