Painting process of aluminum coil gutter

Painting process of aluminum coil gutter consists of coil flattening, pre-treatment, coating and solidification.

The flattening part is also known as the decoiling, during which a mill finish aluminium coil roll is sent into the production line and leveled by a temper mill. After becoming extremely flat and even, the roll enters the storage rack. There are two reels here to ensure that one of them is always in standby state to maintain the continuity of the production line. Then, the storage rack is emptied and the production line continues to run, driving the follow-up process.

The pre-treatment part entails repeated powerful cleaning by water spraying which improves the corrosion resistance and paint sticky ability. The conversion film is formed on the surface of aluminum by chemical method.

The coating process falls on three stages: primer, drying and topcoat. The aluminum coil roll passes through the coating roller and is coated with primer on one or both sides. Then the coated roll is dried and then sent into the coating roller again. Ordinary paints include acrylic primer, polyester, polyimide and fluorocarbon. Basic standards for the painting process are good formability, high hardness, smooth appearance and strong weather resistance.

The solidification process aims to drive off volatile materials and dry up paints on the coated aluminum coil surface. According to the needs of the system, the curing temperature is generally set between 200 ℃ and 300 ℃.