Painting refers to covering the metal or non-metal surface with a protective layer or decorative layer. The painting machinery is a rapidly developing industry based on painting. With the development of industrial technology, coating has developed from manual to industrial automation, and the degree of automation is getting higher and higher. Therefore, the application of coating production lines is becoming more and more extensive, and has penetrated into many fields of the national economy.

The coating process in my country can be simply summarized as: pretreatment → spraying → drying or curing pretreatment → spraying → drying or curing.

With the development of my country's economy and the development of foreign coating technology, through the introduction of technology and the exchange of foreign technology, my country's coating technology has begun to develop rapidly. In terms of automated coating production, the application of electrostatic spraying and electrophoretic coating technology, the development and promotion of powder spraying technology. In particular, the vigorous development of my country's home appliance industry, daily hardware, steel furniture, aluminum components, electrical products, automotive industry and other fields have made the coating industry have made significant progress. Intelligent painting robots have also appeared in the painting production line, all of which represent the rise of the painting machinery industry.

Process requirements

Pre-treatment:

The degreasing tank and phosphating tank liquid are heated and supplemented with water, and the shed fan starts and stops.

Conveying and painting:

Conveyor start-stop operation, operation protection and speed regulation.

Start and stop operation and operation protection of water pump and fan in spray booth.

Drying room:

Water heating drying room electric heating start and stop, automatic temperature adjustment and operation protection.

Start and stop operation and operation protection of thermal circulation fan of moisture drying room.

Start and stop operation and operation protection of the exhaust fan and air curtain of the moisture drying room.

Start and stop of electric heating and automatic temperature adjustment and operation protection in topcoat drying room.

Start and stop operation and operation protection of thermal circulation fan in topcoat drying room.

Start and stop operation and operation protection of exhaust fan and air curtain of topcoat drying room.

System Configuration

PLC selects NA200 series, and is equipped with Nantao Automation 10-inch touch screen, which can complete parameter setting, alarm display, signal display, help information production data display and so on.

System Configuration

Communication:

Use one touch screen to communicate with 3 PLCs, there are 2 232 and 1 485.

Process control:

Although there are a lot of control points, the logic is relatively simple. Main considerations:

① No water protection for the pump, temperature control buffer to avoid frequent heating, etc.

② To realize variable frequency speed regulation on each conveyor belt, each conveyor belt needs to be installed with up and down adjustment buttons to control the frequency conversion frequency.

　　Figure 1: Pre-treatment

　　Figure 2: Painting

　　Figure 3: Drying room

　　Figure 4: Transportation