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.

可以使用熱水對鋁卷進(jìn)行清洗。熱水清洗主要是將基板表面殘留的脫脂劑清洗干凈，保證這些殘留物能溶解其中，以防這些脫脂劑對基板造成二次污染。使用方式多為浸洗和噴淋刷洗的方式。所用水質(zhì)好硬度不要太高，否則，水中的礦物質(zhì)會在基板表面生成礦斑。

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.

熱堿脫脂由于預(yù)涂線線速較快，所以所用的脫脂劑一般濃度較高，典型的脫脂劑含有氫氧化鈉（NaOH）、碳酸鈉（Na2Co3）、水玻璃（Na2SiO3）、磷酸鹽等組份。熱堿脫脂工序一般分兩步處理以確保鋁卷基板表面清洗干凈，且多用噴淋刷洗的方式。

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.

對它進(jìn)行鈍化處理。鈍化處理是通過加壓噴淋、浸涂或輥涂等方式使鈍化劑在基材表面形成轉(zhuǎn)化膜。一般使用加壓噴淋的方式，鈍化液在使用過程中產(chǎn)生的泥渣往往會堵塞噴孔，從而影響噴淋得效果。

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.

浸涂的方式雖然解決了這一問題，但鈍化液的消耗量較大。以上兩種方法在實(shí)際操作中都需要用水沖洗多余的鈍化液，就會產(chǎn)生廢水的回收和凈化問題，輥涂是好的鈍化施工方式，具有涂布均勻、經(jīng)濟(jì)實(shí)用、不需淋洗等優(yōu)點(diǎn)。鋁板一般采用鉻酸鹽/氧化物型處理劑，該類處理劑含有鉻酸鹽、鉻酸、磷酸及促進(jìn)劑氟化物和鉬酸鹽。該類處理劑必須加入磷酸，否則就不能用來處理食品和飲料用鋁板。

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.