Various Method of pre-treatment: 

It could be divided into Wet type (dipping pre-treatment, spraying pre-treatment) , used in thin-walled workpieces (aluminum profiles, cold plate bending forming parts 

And Dry type (box-type,on-line type),used in thick-walled hot-formed workpieces, castings, and hot-rolled profiles

1.Dipping pre-treatment:

Process flow: Immerse the workpiece in the paint, take it out after a certain period of time, remove the excess paint on it, and dry it in a drying chamber or naturally dry it to form a film. There are many methods of dipping, including traditional manual dipping, as well as modern automatic dipping methods such as transmission dipping, centrifugal dipping, rotary dipping, and vacuum dipping.

Working principle:

The workpiece is fed into the paint tank by the conveyor chain. After being immersed in the paint, it is lifted up along the ascending section of the conveyor chain, and then enters a tunnel filled with solvent vapor, where the remaining paint drips and forms a coating.

Advantage: 

It has high production efficiency, low material consumption, simple operation, and wide application range. It is widely used in small hardware parts and equipment with relatively complex structures or electrical insulation parts

2.Spraying pre-treatment: 

Spray-type pre-treatment equipment is commonly used equipment for surface treatment of metal workpieces. It uses a centrifugal water pump to form a high-pressure atomization effect from a nozzle through a pipeline to achieve cleaning purposes

   Process flow : hot water washing, pre-degreasing, degreasing, pickling, surface conditioning, phosphating, water washing, belling, pure water washing

Advantage: The high-pressure atomization effect cleans the surface of the workpiece, and the cleaning fluid is recycled to achieve environmental protection

3.On-line type pre-treatment: ( Traction suspension conveyor , Universal power and free conveyor , Push type suspension conveyor)

Advantage: It can go downhill and turn in space, the layout is free and flexible, and it occupies a small area .

4.Box type pre-treatment:

Usage of box type: It is used for debinding, pre-firing and firing of ceramic materials, electronic components, magnetic materials, powder metallurgy and other products, and can also be used for the heat treatment process of other materials. 

Advantage: 

The material can be heated from within

There is no exhaust heat loss from fuel furnaces, so the thermal efficiency is high

Easy to control the temperature, remote control and fine adjustment

Good operating performance and no pollution to the environment