Xu Yiding: There is still plenty of room for development in electrophoretic coatings

Xu Yiding
Doctor of Science
JinLitai Chemical Co., Ltd. electrophoretic technology manager
engaged in electrophoretic coating research and application work for 8 years
Forum Platform / Coatings and Protection
Coatings and Protection: As a branch of the coating system, what are the key properties of electrophoretic coatings? How do you technically support these performance?
: The key properties of electrophoresis coatings are closely related to their application areas and core objectives. Taking electrophoresis coating as an example, slowing down the corrosion of substrate is the core goal of electrophoresis coating. To achieve this goal, adhesion, corrosion resistance, swimming transmission is the most critical performance indicators

. Adhesion reflects the combination of coating and substrate, corrosion resistance reflects the comprehensive ability of coating insulation corrosion media, swimming permeability for different areas, especially the inner cavity coating and effective protection to provide protection.
and modified electrophoresis resin is the core of electrophoretic coating design. With a certain scale of electrophoretic coatings companies have the ability to independently develop and improve the resins used in coatings. Resin molecular weight, branching degree, modified group, curing agent, etc. will affect the comprehensive performance of the coating.Coatings and Protection: What are the main applications of electrophoresis coatings?
Xu Yiding: electrophoresis coating applications are extensive, in addition to the core automotive and automotive-related industries, has been gradually expanded to electrical appliances, furniture, light industry hard metal, instruments and other fields.
In the automotive industry, electrophoresis coating covers the body of automobiles, cargo boxes, frames, chassis, parts coating,
in the field of furniture, fire doors, lockers, metal structure forms widely used electrophoresis coatings,
in the field of light industry hardware, locks, bicycle accessories, camera holders, gift box levers and many other fields using electrophoresis paint.
can be said that the application of electrophoresis coatings is not static, with the optimization of coatings and coating technology, is still being developed and broadened.
Coatings and Protection: What are the main varieties of cathode electrophoresis coatings? What are their characteristics?
: At present, the commercially available cathode electrophoresis coatings can be divided into protection, decoration, special needs of the three categories.
protective cathode electrophoresis coatings usually have strong corrosion resistance, high swimming transmission characteristics, the current automotive body and auto parts in the field of the use of mainly protective electrophoresis coatings.
decorative cathode electrophoresis coatings usually have outstanding features in appearance, such as color electrophoresis, high-gloss electrophoresis, electrophoresis, etc. , mostly used in light industry metal, furniture and other fields.
Special needs cathode electrophoresis coatings usually have characteristics on a certain indicator, non-temperature-resistant materials (rubber, etc.) under the electrophoresis coating, you can choose low-temperature electrophoresis coatings;
Coatings and Protection: What are the application prospects for a cathode electrophoresis coating on the bottom surface?
Xu Yiding: The bottom of the one cathode electrophoresis coating overcomes the shortcomings of the traditional cathode electrophoresis coating in sunlight, ultraviolet radiation under the rapid powder failure, expands the use of the paint window, widely used in commercial vehicles, such as two, three types of chassis with a certain outdoor storage cycle of the application area.
Compared with the dual coating process, the bottom surface coating has natural advantages, reducing the spraying and baking process not only in the coating line design, coating consumption has brought visible economy and convenience, but also greatly reduced the energy consumption of the coating process, waste water emissions, more in line with the concept of green coating, environmental protection coating.
bottom surface integrated electrophoresis coating also has its own bottleneck, on the one hand, its comprehensive protection performance can not achieve the effect of dual coating process, especially for long-term outdoor operation of the components, the choice of dual coating process is more suitable;
with the further development of coating technology, with better comprehensive performance of the bottom surface integrated cathode electrophoresis coatings continue to come out, this field will have a broader development prospects.
Coatings and Protection: What typical paint diseases occur during electrophoresis coating? And how to respond?
: defects and ills in the process of electrophoresis coating include particles, shrink holes, fluid marks, pinholes, spots and so on. Because electrophoresis coating contains many processes, the causes of the same type of defects are not the same, so the solution is not completely consistent. When defects occur, the main processes of defect generation are usually locked by means of rapid cross-comparison, and then containment and preventive measures are implemented for the disease.
take the shrink hole defect as an example. The reasons for shrinking holes in electrophoresis coatings are usually related to three systems:
(1) pre-treatment system: poor oil removal effect on the surface of the work surface; The pre-treatment system can be quickly checked by mounting a standard model before electrophoresis, the electrophoresis system can be quickly checked by the laboratory configuration of fresh electrophoresis/sink, and the baking system can be quickly checked by laboratory baking. If the locking electrophoresis system is the main process of generating shrink holes, it can be implemented to remove oil filter bag replacement, laying oil filter cotton, enhance the paint surface ratio, improve anti-shrink hole additives and other measures to quickly contain, while the source of pollution detection and prevention, such as the transport link liquid disk oil droplets leak to the tank.
Coatings and Protection: Electrophoresis coatings have been improving in performance since they were first developed. How much room do you think there will be for future performance improvements in electrophoresis coatings?
: Although electrophoresis coatings have been around for half a century, they have been accompanied by the development of coating technology and coating needs. For different sub-applications, electrophoresis still has a lot of room for development, which includes the performance of coatings, but also includes the application of coatings.
e.g. low-temperature cured electrophoresis coatings that advocate energy-saving concepts, high-level body electrophoresis coatings with compact water-based paint processes, low VOCs that advocate environmental protection concepts, low heavy metal electrophoresis coatings, high-edge protective electrophoresis coatings focused on rough materials, and high-swimming permeable electrophoresis coatings that match phosphorus-free pre-treatment. coating and protection: environmental regulations are becoming more and more stringent, how has the impact on the current electrophoresis coating technology?
: The impact of strict environmental regulations on electrophoresis coatings is significant, not only has a direct impact, but also has an indirect impact.
Take VOC as an example, in the discussion of the latest edition of The Limits of Harmful Substances in Vehicle Coatings, the limit for electrophoresis coatings is 250g/L, the lowest or most stringent of all paint types. This requirement drives coating suppliers to more rigorously audit their raw materials, formulations and production processes.
strict environmental regulations make phosphorus-free pre-treatment technology, water-based paint technology, powder coating technology has been more attention and development. In order to match the technical characteristics of phosphorus-free pre-treatment, water-based paint and powder coating, electrophoresis coatings also need to be adjusted and optimized accordingly. It also promotes the development of electrophoresis coating technology.
coating and protection: electrophoresis coating technology is restricted by electrophoresis tank, for the super-large frame is there any way?
Xu Yiding: electrophoresis coating process more, each tank body and baking process will be subject to the volume of the coating restrictions. Therefore, electrophoresis coating technology is usually suitable for coating large quantities, medium size, fixed structure of the coating. Before choosing electrophoresis coating for an oversized frame, more full consideration needs to be given to economy and operability, and one possible solution is to split it into small structures, coat it and then assemble it.
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