Order the production line, we want to establish the coating production line to determine what: first of all, to determine the production program, complete the process design, program planning, and then to non-standard equipment design, manufacture and installation. Therefore, process planning and program planning are the foundation of the production line. The correct and reasonable route will have a decisive influence on the operation of production and the quality of the product. The main contents of the process design include: surface coating quality requirements, pre treatment methods, spraying methods, process, coating properties, spraying environment, time, etc..
1. The purpose of painting:
Through coating construction, the coating can form a firm and continuous coating on the surface of the coating, so as to play its decorative, protective and special functions
1.1 coating elements
The key of painting project is painting process and equipment, painting material, working environment and painting management.
The quality of the coating material is the basic condition for obtaining high quality coating. Coating process, equipment and painting environment are the necessary conditions for full application of coating materials, high quality coating, low production cost and economic benefits. Coating management is to ensure the implementation of the established process, to ensure the stability of coating quality, to achieve the purpose of painting and the best economic benefits of the important conditions.
2 、 coating equipment
The main coating equipment is divided into pre coating surface pretreatment equipment, painting equipment, coating drying and curing equipment, mechanized conveying equipment, dust-free, constant temperature and humidity air supply equipment, and other ancillary equipment.
2.1 coating surface pretreatment equipment
The purpose of 2.1.1 preprocessing:
The removal of coated with a foreign body, such as skin oxidation, rust, grease, suitable for a good basement in the coating requirements, such as oxidation, phosphating, passivation, to ensure that the coating has good corrosion resistance and decorative properties.
2.1.2 pretreatment equipment is mainly divided into physical and chemical forms.
Physical formula:
Remove impurities attached to the surface of the steel plate and remove impurities such as grease with a thinner.
If there is any sulfate or corrosive salt, it should be washed with clean water and dried by compressed air.
On the pretreatment line of steel plate, the oxide scale, rust and other impurities are removed by blasting or sand blasting, and then the surface of the steel is removed by vacuum cleaner or purified compressed air.
Chemical formula：
Impregnation, injection, dip spray combined, spray - dip - spray combination.
It is mainly composed of tank, tank heating system, ventilation system, tank mixing system, phosphating slag removal system, oil-water separation system and so on. Among them, phosphating, slag removal and oil-water separation equipment are the key systems. The methods of phosphating and slag removal include sedimentation method, rotating liquid separation method, inclined plate sedimentation method, bag filtration method, plate and frame filter press, and other common methods.
The separation of oil and water mainly includes adsorption, ultrafiltration, hot oil separation and centrifugation.
2.2 painting equipment
2.2.1 painting method
There are many methods of painting, such as brushing paint, dipping paint, air spraying, high-pressure airless spraying, electrostatic spraying, electrophoretic painting, painting, roll coating, etc..
2.2.2 painted environment
The ideal paint environment shall meet the requirements of good lighting, proper temperature, humidity and cleanliness of the air, good ventilation and fire protection and explosion protection requirements.
2.2.3 painting equipment
The function of painting equipment is to limit spray paint mist in a certain area and to be filtered so that the operator can meet the hygienic conditions and the safe working environment. In addition, construction conditions with certain temperature, humidity and cleanliness should be provided.
2.2.3.1 classification of common spray booth
1) dry spray booth: suitable for spray painting of small batch of workpieces;
2) spray type spray booth: suitable for spray painting of small workpieces;
3) water curtain painting room: suitable for painting of middle workpiece;
4) water jet paint booth: suitable for painting large workpieces with high decorative requirements.
Main structure of 2.2.3.2 painting room
1) chamber: the function is to limit spray paint to a certain range.
2) paint mist filter device: dry and wet two.
Dry: filter paint mist by baffle or filter paper.
Wet: the paint mist particles are separated from the air by the mixing of gas and water.
3) water supply system: to ensure the normal circulation of water needed in the wet spray booth.
4) ventilation system: it is composed of air supply and exhaust air, providing air with certain temperature, humidity and cleanness to the equipment, and ensuring the indoor air to be laminar flow.
5) lighting: ensure that the equipment has good illumination.
2.2.4 impregnating equipment
The workpiece is submerged in the paint solution, and the surface of the workpiece is adhered with a coating with the adhesion of the paint solution.
2.2.5 electrostatic spraying equipment
Electrostatic painting: according to the electrostatic field on the principle of charge and achieved. It usually consists of electrostatic painting booth, high voltage electrostatic generator, electrostatic spray gun device, paint supply device, safety device and so on.
2.2.6 electrophoresis coating equipment
Electrophoretic coating: an ionized coating of particles dispersed in water under an applied electric field that is coated with an electrophoretic coating to form a protective coating.
2.2.7 powder electrostatic spraying equipment
Powder coating has the advantages of good economy, no environmental pollution and high efficiency, and the coating thickness can reach more than 50 mu m at one time.
Powder electrostatic spraying equipment mainly includes powder spraying room, high voltage electrostatic generator, electrostatic powder gun and powder supply device。