1.Industrial Overview

In the field of automobile manufacturing, baking paint is widely used in the coating processing of body, frame and other components. Compared with traditional manual painting, baking painting technology has many advantages such as high production efficiency, high precision, and high degree of automation. At the same time, baking paint can make the car surface achieve higher gloss, hardness and durability, and can maintain the beauty and functionality of the car body surface for a long time.

Paint also plays an important role in the field of automotive repair and restoration. Whether it is a small area scratch repair or a large area car body repair, spray painting is an indispensable link. The application of the baking paint process can ensure that the repaired paint surface exactly matches the original paint surface, while ensuring the durability and anti-corrosion performance of the repaired part.

With the rise of the car beauty industry, baking paint has also been more widely used. Car beauticians can provide a full range of car beauty services through paint application. For example, paint restoration, polishing, maintenance, etc. can all be achieved through the high-temperature drying and coating technology of the paint room. These services can not only repair damage to the surface of the car body, but also increase the gloss and overall appearance of the car.

2.Process Description and Control Requirements

1) Process Description：

Body sheet metal treatment: including cleaning, repairing, grinding and other work to ensure that the body surface is flat, clean and smooth

Primer: Primer is the first coating layer in the car painting process. Its main function is to protect the surface of the car body and enhance the adhesion of the color. Primer can also fill in small defects and surface irregularities and improve the adhesion of the topcoat.

Baking primer: Send the primed car body into the baking room and solidify it at high temperature to make the primer stronger and avoid problems such as paint peeling and cracking.

Topcoat: Topcoat is the second coating layer in the automotive painting process. Its main function is to provide the color and gloss of the car body. Topcoat is divided into two types: base paint and clear paint. The clear paint exists to protect the base paint.

Baking topcoat: Send the topcoated car body into the baking room and solidify it at high temperature to make the topcoat brighter and more durable, avoiding scratches, fading and other problems on the surface.

Polishing treatment: After the topcoat is baked, polishing treatment is required to make the surface of the car body smoother and more delicate, and to improve the texture of the car body.

2) Control Requirements：

    The external air is filtered by the primary filter and sent to the roof by the air inlet fan. It is filtered and purified by the top filter again before entering the room. The air in the room adopts the full-down type, flowing downward at a speed of 0.2-0.3m/s, so that the paint mist particles after painting cannot stay in the room, and the high-temperature exhaust gas is directly discharged out of the room through the bottom air outlet by the exhaust fan. It is discharged into the air through the purification tower. The VB series general VFD was selected on site to work with the steam exhaust fan. The start signal is given by the HMI in the operation workshop, and goes through the PLC relay terminal to the frequency converter digital input terminal for controlling start and stop, and at the same time setting the speed. It is converted into an analog output signal by the PLC and sent to the VFD analog input terminal to adjust the output frequency ( i.e. motor speed).

3.Solution

•  The VB series VFD has definable digital and analog input terminals, and can be externally connected to PLC relay terminals and analog output terminals to achieve external start, stop and speed regulation. Operators can remotely control equipment, improving system security.

• The VB series VFD comes with a soft start function, a smooth output curve, and a small starting current, which can avoid the impact on the power grid. It also has all-round protection functions such as overcurrent, overvoltage, overload, and overheating. When external lines or motors When an error occurs, it can be detected in time and trigger a protective shutdown. The fault location is accurate, which facilitates on-site electrician investigation and effectively reduces maintenance time and labor costs.

• VB series VFD can set different V/F curves and torque boost and other related parameters according to the load type, so as to better match the characteristics of on-site equipment and exert the best performance.

 Parameter Settings

4. Photos at Site