With this equipment, degreasing, water rinsing and phosphate coating are performed on the surface of steel sheets as a pretreatment for painting. The pretreatment process is so important that it enhances the rust preventive power and paint adhesion to the object which determines the final painting quality.

Design

The process basically consists of five steps, i.e. (1) Degreasing (2) Water rinsing (3) Surface conditioning (4) Phosphate coating (5) Deionized water rinsing. When designing a line, the treatment method shall be determined according to various kinds of conditions such as the degree of dirt on the surface, shape, size, quantity, conveying style of the object. Treatment time, number of processes, chemical reactions, and energy saving are also taken into consideration in designing.

Treatment Method

There are three treatment methods, (1) Dip (2) Spray (3) Spray & Dip. The Full-dip method is adopted in most cases of car body pretreatment aiming at rust prevention to the inner parts.

With this e-coat equipment, the whole body of the object is dipped into a tank filled with water-soluble paint. The paint adheres to the object due to a deposition by giving electric voltage to both the object and the electrode in the paint solution. This equipment is characterized by the evenness of the paint film and also the strong paint adhesion. This equipment is usually adopted for the Primer coating process.

Auxiliary Equipment

The UF(Ultra Filtration) equipment is used for condensing the film-forming ingredients by filtrating the e-coat paint. The filtrate is used for a multiple cleaning process to wash away surplus paint adhered to the object.

The paint booth consists of a preparation room, spray booth, setting booth and air conditioner. There are two types of spray booths ----dry-type and wet-type. The spray booths have five shapes, which are one side, both sides, open, tunnel and circle. Several methods are adopted for arresting paint mist, such as back shower and venturi which are all wet-types using water circulation. Dry filters can also be used as a simple method for arresting mist. We provide high-efficiency paint booth with a clean operation environment and energy saving function to meet our customer's request.

The oven is broadly classified into two types, i.e. 'Dry-off oven' for vaporizing water after pretreatment and ‘ Baking oven‘ for curing the paint film after painting. With the baking oven, its inner temperature is determined according to the type of paint (usually 110c-200c), and either direct heating (city gas, natural gas) or indirect heating (kerosene, heavy oil, gas, steam) can be selected according to the type of heat source. A dark-infrared ray heater utilizing radiation energy is installed in the heat-up zone, which is effective for energy saving and also for dust prevention. An infrared heater or far-infrared heater using gas or electricity can also be used.  And as a countermeasure against air pollution, a fume incinerator system is available too.