Analysis of process management of electrophoretic coating line

Now due to many electrophoretic coating line process management (consciousness) backward and other lack of knowledge in maintenance, directly lead to the electrophoretic paint production after the uneven quality of paint film. In this paper, based on the author's experience, the main points of process management of electrophoretic coating line are briefly described, hoping to help friends who need to understand the maintenance of process equipment of coating line. Replacement of each wash: It is recommended to replace each wash frequently.

1. The advantages of frequent replacement of electrophoretic washing are as follows:

1) Frequent replacement of washing water after degreasing will reduce oil pollution into the next process as much as possible, especially into the electrophoresis tank, which will lead to shrinkage problems;

2) Frequent replacement of washing water after electrophoresis will reduce the appearance of dry paint marks and secondary flow marks. Replacement frequency is recommended once per shift (when one shift is in full capacity). Personal recommendation in the electrophoresis line using fresh pure water spray washing (or high pressure water gun spray pure water wash), will have a good benefit to the appearance of electrophoresis paint film.

3) It is recommended to open an overflow tank or overflow hole for each washing tank to facilitate the discharge of dirty surface (oil slick, ash, etc.).

Two, about pretreatment: it is recommended to do pretreatment before the workpiece is on line.

Including grinding floating rust, pre-scrubbing oil removal, so that the workpiece surface no obvious floating rust, heavy rust, no obvious oil. In particular, the degreasing tank has no circulation or bad circulation, bad temperature line, we must strengthen the pre-scrub, only in this way can achieve good degreasing effect. Effective pretreatment can also shorten the degreasing time, prolong the service life of degreasing tank and guarantee the degreasing effect.

Three, sewage sewage tank.

Many electrophoretic coating lines, when installing equipment, forget to install a drain tank around each tank, which directly leads to the problem of not being able to drain water. At the same time, it is suggested that a sewage tank station should be set aside when the electrophoresis line is off. The purpose is to facilitate the drying of the electrophoresis work piece on the line, and to do manual spraying cleaning in this station to improve the appearance of the paint film. Phosphating: phosphating tank liquid is strong acid, so the phosphating tank body must be added with anticorrosive lining, the treatment method is recommended as far as possible to use spray combined type, do not recommend only spray, can only use immersion treatment.

Spray treatment, because the spray volatilization is large, the phosphating tank parameters control requirements are higher. The circulating pump is made of stainless steel or plastic. The circulation rate is 2 times per hour and the lift is about 30 meters. If it is not possible, the plastic pipe of compressed air can be used to go deep into the tank for manual stirring. Many electrophoretic coating lines generally do not have phosphating slagging device, and the slagging is done by standing for a period of time with submersible pump pouring tank. It is suggested to consider adding a high tank settling slagging or building double phosphating tank. The heating method of phosphating is the same as that of degreasing. It is not recommended to directly use steam or flue gas to heat the tank liquid, which will lead to the precipitation of phosphating components and produce additional sediment, affecting the stability of the tank parameters.