Pre-treatment process flow

1. Workpiece material iron (zinc phosphating) degreasing - water washing - rust removal - surface conditioning (optional water washing) - phosphating - water washing - water washing - drying Drying (sun-drying)

Simple and safe, it pollutes the environment a lot, and oil removal is usually the most likely to cause problems.

Iron (iron-based phosphating) degreasing - washing - rust removal - surface conditioning - phosphating - washing - washing - drying is relatively environmentally friendly, but has high operational requirements , it can’t be done with just a few years of experience, and it’s often prone to problems.

2. Degreasing the workpiece material aluminum - water washing - phosphorus passivation (actually the best is hexavalent chromium solution) - water washing

Aluminum turns black when exposed to acid, so There is little rust removal (pickling) in between. If there are a lot of white rust spots, it must be pickled before passivation. It must be accurate to the second. Wash it with water immediately and proceed to the next step.

If the iron workpiece needs to be treated before spraying, the best solution is to soak it in a tank to remove oil - wash with water - remove rust - surface conditioning (apply thin oil) - (spray with pendant) - - Degreasing - Water washing - Phosphating - Water washing

I personally do not recommend spraying for degreasing, and I personally oppose spraying for pickling. The gap between the workpieces in the tank must be left well.

Precautions for pre-processing: 1. Degreasing must be thorough. Always use a scoop of oil to remove the oil. If the oil is not removed properly, the consequences will be cloudy. 2. Go to the next process immediately after rust removal. The metal will rust back only in a few seconds, so you don’t have time to blink. 3. When using water for pre-treatment, you must have the mentality of being reluctant to let go of the child and unable to trap the wolf. Each washing section must be large, urgent and ruthless. Many people think that washing is just a matter of rinsing and that's it. Sorry, you are wrong. There is a foreign company in Suzhou Park. There is no water washing after spraying to remove oil. The putty is 1 mm thick after drying in pre-treatment. A company in Shaoxing cannot wash it clean after rust removal, and the workpiece after pre-treatment is comparable to Peking Opera facial makeup. A company in Yuyao, Ningbo saved some water after phosphating. Three months later, the product began to peel.