Study Of Methods For Finding And Preventing Shrinkage During The Commissioning And Start-up Of Auto Painting ED

Since the21st century， auto industry in China has developed rapidly, especiallyfor car industry. China has become the second largest auto market. Along with thedevelopment of auto industry, all kinds of technologies have moved in rapiddevelopment. Car painting technology is developing more rapidly among theindustries and it is one of the key technologies concerned with the life and the look ofcar body.Shrinkage is very common in electrophoretic painting. The paper investigatesand analyzes the happening mechanism of the shrinkage and the productionprocedures where shrinkage happened. It also checks the current process flow. Theshrinkages on bonnet are running at a rate of sixty a bonnet,20%in presentprocedures. Meanwhile, it presents the lubricant oil bumping experiment, washingdipping plate experiment and all kinds of crossover experiments for each the mainprocedures, such as painting, pretreatment, ED and drying. The results show that it ismost polluted by lubricant oil while UF washing and drying furnace carrying. The twoprocedures are where the shrinkage always happens and the amounts of shrinkage are5per plate and4.4per plate.According to the results of experiments and tests, the check procedure aftershrinkage happened is summarized and collected. It also provides solutions todecrease shrinkage while building production line in the future and remarks tocommissioning. Practice proved that, the method can reduce occurrence rate of bonnetshrinkage on new production line by10%and the amount of shrinkage is reduced93.71%. The damage of shrinkage is reduced and the quality cost of new productionline is also reduced. The satisfactory results achieved when it used in productionpractice.