Cause 1 tank liquid base ratio is too high. 2 The coated workpiece and the hanger that enter the electrophoresis tank are not clean. 3 The electrophoresis tank has too much impurity ions in the bath due to poor filtration, and the conductivity is high. The amount of cosolvent in the 4 bath is low. 2. Prevention methods 1 Consult with the supplier to provide a low pigmentation coating to adjust the bath. 2 Strengthen the filtration of the pretreatment liquid , reduce the residue content of the phosphating solution, strictly control the water quality after phosphating, and the phosphating residue floating on the surface of the workpiece; regularly clean the hanger to loosen the dirt. 3 Strengthen the filtration of the electrophoresis bath. Regularly clean and replace the filter unit , strictly control the pH value of the bath and the introduction of alkaline substances to prevent resin precipitation. 4 Periodically check the solvent content of the bath, if it is low, it should be added in time. To ensure the stability of the bath. (2) Shrinkage, sinking Cause 1 tank liquid and pigment ratio is out of balance, low pigment content. 2 The pre-treatment of the coated workpiece is poor or the phosphating film is covered with oil, dust, etc. after cleaning. 3 tank liquid mixed with oil, dust, oil floating in the tank surface or emulsified in the bath. 4 After the electrophoresis, the rinse solution is mixed with oil. 5 foreign oil contaminated the electrophoretic coating film. 6 The drying room is not clean, and the circulating air contains oil. 2. Prevention method 1 Adjust the pigment base ratio of the bath and add color paste to increase the pigment content. 2 Strengthen the management of the degreasing process of the coated workpiece to ensure that the phosphate film is not contaminated twice. 3 Install a degreasing filter in the tank circulation system and check the source of oil contamination to completely remove the oil method. 4 Strengthen the detection of the water quality of the rinse liquid, and periodically clean and replace the filter bag to ensure the quality of the post-wash water filtration. 5 Keep the coating environment clean and remove substances harmful to painting, especially those containing organic silicon materials (such as cable, drawing oil, anti-rust oil, anti-slag adhesive, sealant, etc.), painting workshop and The raw materials and auxiliary materials used in the equipment and process media of the relevant workshops must not contain ester ketones. 6 According to the process regulations, clean the drying room regularly to keep the drying room and circulating hot air clean. Auto Reel Springs,Spring For Retractable Cord Reels,Flat Coil Springs,Return Coil Springs Ningbo Yunsheng Elastic Components Co.,Ltd , https://www.yunshengsprings.com
Common film defect problems and prevention methods in electrophoresis construction
Although electrophoretic coating is the dynamic balance of a large number of operating variables, the operator can monitor and adjust the control parameters of the electrophoretic coating process from time to time to obtain good appearance, film thickness and physical properties. Therefore, when a paint film defect is detected, it should be subjected to a series of accurate and reliable analysis, and then a solution is proposed in time. The most common paint film defects in electrophoresis construction include rough coating film, shrinkage hole, pinhole, spot, thin film, excessive film thickness, water mark, and thin film on the inner surface of the workpiece, which causes these defects. It is not a single factor. The following is a brief introduction to the causes and prevention methods of paint film defects.