來源:http://www.gbpeixun.com/ 發布時間:2020-11-05
鋁卷在成卷之前,需要做一些預處理工段,以保證鋁卷表面的清潔。以免其表面存在殘留的油脂及潤滑劑,對涂裝及使用產生影響。所以,鋁卷在成型前要對它進行以下幾個方面的額預處理。
Before the aluminum coil is rolled, some pretreatment sections are needed to ensure that the surface of the aluminum coil is clean. In order to avoid the existence of residual grease and lubricant on its surface, which will affect the coating and use. Therefore, aluminum roll in the following aspects of the amount of pre-treatment.
一,可以使用熱水對鋁卷進行清洗。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。所用水質好硬度不要太高,否則,水中的礦物質會在基板表面生成礦斑。
1、 The aluminum coil can be cleaned with hot water. Hot water cleaning is mainly to clean the residual degreasing agent on the surface of the substrate, so as to ensure that these residues can be dissolved, so as to prevent the secondary pollution of the substrate caused by these degreasers. The usage is mostly immersion and spray brushing. The best water quality should not be too high hardness, otherwise, minerals in water will form mineral spots on the surface of the substrate.
二,熱堿脫脂由于預涂線線速較快,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。
2、 Due to the fast linear speed of precoating line, the degreasing agent used in hot alkali degreasing is generally high. The typical degreasing agent contains sodium hydroxide (NaOH), sodium carbonate (Na2CO3), sodium silicate (Na2SiO3), phosphate and other components. The hot alkali degreasing process is generally divided into two steps to ensure that the surface of aluminum coil substrate is clean, and spray brushing is often used.
三,對它進行鈍化處理。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化膜。一般使用加壓噴淋的方式,鈍化液在使用過程中產生的泥渣往往會堵塞噴孔,從而影響噴淋得效果。浸涂的方式雖然解決了這一問題,但鈍化液的消耗量較大。以上兩種方法在實際操作中都需要用水沖洗多余的鈍化液,就會產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、經濟實用、不需淋洗等優點。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。
3、 It is passivated. Passivation treatment is to form conversion film on the surface of substrate by pressure spray, dip coating or roller coating. Generally, pressurized spray is used. Sludge produced in the process of passivation liquid often blocks the spray hole, thus affecting the spray effect. Although dip coating can solve this problem, the consumption of passivation solution is large. The above two methods need to wash the excess passivation liquid with water in actual operation, which will lead to the problem of wastewater recovery and purification. Roller coating is the best passivation construction method, which has the advantages of uniform coating, economic and practical, and no need of washing. Generally, chromate / oxide type treatment agent is used for aluminum plate, which contains chromate, chromic acid, phosphoric acid and accelerant fluoride and molybdate. Phosphoric acid must be added to this kind of treatment agent, otherwise it can not be used to treat aluminum plate for food and beverage.