来源:/ 发布时间:2020-11-05
铝卷在成卷之前,需要做一些预处理工段,以保证铝卷表面的清洁。以免其表面存在残留的油脂及润滑剂,对涂装及使用产生影响。所以,铝卷在成型前要对它进行以下几个方面的额预处理。
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。
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,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。
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,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。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。
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.