Coating line pre-treatment equipment can be used to remove all kinds of oil stains (such as lubricating oil, emulsion, grease, sweat, etc.) and dust on the surface of the object to be cleaned before painting. The pre-treatment process that makes the coated surface clean is an indispensable process before the coating process. The kind of chemical treatment or mechanical processing treatment (such as shot blasting, etc.) applied to the coated surface is according to the substrate and surface condition of the coated object, and the coating process requirements are selected.
The pre-painting treatment includes three parts: degreasing (degreasing), derusting and phosphating.
The content of process design mainly includes: processing method, processing time, process flow and so on.
Treatment methods include full immersion type, full spray type, spray immersion combination type, brush coating type, etc.
Treatment time once the treatment method and treatment temperature are selected, the treatment time should be determined according to the degree of oil stain and rust of the workpiece. Generally, please refer to the processing time requirements of the pre-treatment agent instruction manual.
Process flow according to the oil stain, rust degree of the workpiece and the primer requirements, it is divided into different process flows：
Completely rust-free workpieces
Pre-degreasing-water cleaning-surface adjustment-phosphating-water cleaning-drying (the electrophoresis primer can be directly dried into the electrocoating process tank without drying). This is a standard four-station process and has a wide range of applications. It is suitable for the pretreatment of various cold-rolled plates and machined rust-free workpieces. It can also add a conditioning agent to the degreasing tank to reduce one conditioning process.
General oil, rust, oxide scale mixed workpieces
Degreasing and rust removal "two in one"-water cleaning-neutralization-surface adjustment-phosphating-water cleaning-drying (or direct electrophoresis). This process is the most widely used process in China and is suitable for the pre-treatment of various types of workpieces (except heavy oil pollution); if medium temperature phosphating is used, the table adjustment process can also be omitted, and the simple plate type workpiece can also save the neutralization. The process becomes a standard four-station process with rusty parts.
Heavy oil stains, rust, scaled workpieces
Pre-degreasing-water cleaning-degreasing and rust removal "two in one"-water cleaning-neutralization-surface adjustment-phosphating-water cleaning-drying (Or directly into the electrophoresis tank). For heavy oil-contaminated workpieces, pre-degreasing should be performed first to remove most of the grease to ensure a completely clean metal surface after the next two-in-one degreasing and derusting treatment.
For specific methods, please contact XMT, we will provide a professional coating line pre-treatment solution.