Before forming the aluminum coil, some pre-treatment sections need to be done to ensure the cleanliness of the surface of the aluminum coil. To avoid the presence of residual grease and lubricants on its surface, which may have an impact on painting and use. Therefore, the aluminum coil needs to undergo the following pre-treatments before forming.

可以使用热水对铝卷进行清洗。热水清洗主要是将基板表面残留的脱脂剂清洗干净，保证这些残留物能溶解其中，以防这些脱脂剂对基板造成二次污染。使用方式多为浸洗和喷淋刷洗的方式。所用水质好硬度不要太高，否则，水中的矿物质会在基板表面生成矿斑。

Hot water can be used to clean the aluminum coil. Hot water cleaning mainly involves cleaning the residual degreasing agent on the surface of the substrate to ensure that these residues can be dissolved, in order to prevent these degreasing agents from causing secondary pollution to the substrate. The usage methods are mostly immersion and spray brushing. It is best not to use water with too high hardness, otherwise minerals in the water will form mineral spots on the surface of the substrate.

热碱脱脂由于预涂线线速较快，所以所用的脱脂剂一般浓度较高，典型的脱脂剂含有氢氧化钠（NaOH）、碳酸钠（Na2Co3）、水玻璃（Na2SiO3）、磷酸盐等组份。热碱脱脂工序一般分两步处理以确保铝卷基板表面清洗干净，且多用喷淋刷洗的方式。

Due to the fast pre coating line speed, the concentration of degreasing agents used in hot alkali degreasing is generally high. Typical degreasing agents include sodium hydroxide (NaOH), sodium carbonate (Na2Co3), water glass (Na2SiO3), phosphate, and other components. The hot alkali degreasing process is generally divided into two steps to ensure that the surface of the aluminum coil substrate is clean, and spray brushing is often used.

对它进行钝化处理。钝化处理是通过加压喷淋、浸涂或辊涂等方式使钝化剂在基材表面形成转化膜。一般使用加压喷淋的方式，钝化液在使用过程中产生的泥渣往往会堵塞喷孔，从而影响喷淋得效果。

Perform passivation treatment on it. Passivation treatment is the process of forming a conversion film on the surface of the substrate by pressure spraying, immersion coating, or roller coating. Generally, pressurized spraying is used, and the sludge generated by the passivation solution during use often blocks the spray hole, thereby affecting the spraying effect.

浸涂的方式虽然解决了这一问题，但钝化液的消耗量较大。以上两种方法在实际操作中都需要用水冲洗多余的钝化液，就会产生废水的回收和净化问题，辊涂是好的钝化施工方式，具有涂布均匀、经济实用、不需淋洗等优点。铝板一般采用铬酸盐/氧化物型处理剂，该类处理剂含有铬酸盐、铬酸、磷酸及促进剂氟化物和钼酸盐。该类处理剂必须加入磷酸，否则就不能用来处理食品和饮料用铝板。

Although the dip coating method solves this problem, the consumption of passivation solution is relatively high. Both of the above methods require washing excess passivation solution with water in practical operation, which can lead to wastewater recovery and purification problems. Roller coating is the best passivation construction method, which has the advantages of uniform coating, economic practicality, and no need for rinsing. Generally, aluminum plate adopts chromate/oxide type treatment agent, which contains chromate, chromic acid, phosphoric acid, accelerator fluoride and molybdate. This type of treatment agent must be added with phosphoric acid, otherwise it cannot be used to treat aluminum plates for food and beverages.