The working principle of coating aluminum coil mainly includes two steps: pretreatment of aluminum coil and coating baking.
Pretreatment of aluminum coil:
First, clean the lubricating oil, anti-oxidation grease and various dirt attached to the surface of aluminum coil during rolling, and remove the precipitation of impurities such as silicon, magnesium and copper on the surface of aluminum.
Then, add some chemical raw materials to treat the aluminum coil to form a dense honeycomb oxide film on its surface. The purpose of this step is to make the paint and aluminum coil tightly combined when the aluminum coil is roller coated, and have good adhesion.
Coating baking:
The aluminum coil after chemical coating is sent to the coating line and painted with the color specified by the customer.
In the first stage, precision coating is carried out in a closed and dust-free state using a precision three-roll reverse roller coating machine to control the coating thickness and appearance quality.
In the second stage, the baking process is divided into four furnace zones, with different temperatures set to bake the painted aluminum coil. By high-temperature baking, the paint molecules are linked and solidified, so that the solvent resistance, hardness, flexibility and weather resistance of the coating are all in the best state.
Through these two steps, the coated aluminum coil has good gloss, adhesion and corrosion resistance1.
