An electrically insulated coating in a powder coating

In the field of new energy vehicles, through series of multi-group battery packs as a power source, to achieve zero-emission green cars throughout the country explosive development. As a new energy vehicle battery pack, the distance between adjacent batteries is small, the driving process is prone to high heating temperature, so the quality of insulation materials between the batteries is the key to determine the good operation of automotive power batteries.
Traditional power battery multi-use insulation paper for electromagnetic insulation protection and packaging use, insulation paper has good insulation and flexibility, but because of the complexity of the power battery production process, and the insulation paper and battery shell in the middle of the gap, easy to produce partial discharge affecting the life of the battery, thereby increasing the uncertainty of electric vehicles in the process of driving
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powder coating as a high-performance material in the field of environmental protection is the most matched in the field of new energy, and as a new energy electric vehicle insulation powder coating not only has simple construction, a spray molding easy to install and transport, coating thickness of 100-150um, impurities and metal particles for the coating of electrical insulation performance has a greater impact, so the need to use special insulation powder production equipment.
different raw materials, curing temperature and time, the pre-treatment method of the work piece has a great impact on the insulation performance of the powder coating of aluminum batteries. Under certain thickness conditions, the dosage of different kinds of resins, curing agents, catalysts and fillers have an effect on the pressure resistance of the insulation of the cured coating, the degree of electric shock perforation and the pass rate of electric shock.
resin is the most important component of powder coating film material, its performance parameters must have a significant impact on the insulation of the coating, bisphenol A epoxy resin itself has excellent electrical properties, heat resistance and mechanical strength, chemical resistance is very good, the manufacture of insulation powder coating excellent varieties. According to literature research records, the two-step production of E-12 epoxy resin electrocution strength is significantly better than the one-step E12 epoxy resin, all meet the requirements of customer knock-through voltage ≥5KV. One-step synthesis, the resin relative to the molecular weight distribution is wide, high organchlorine content, not only affect the curing speed of the coating, but also affect the electrical insulation performance of the coating, the formation of the cross-link density of the coating is not high, so the coating break through voltage is not high. When the two-step method is synthesized, the reaction is equal phase, the chain growth is relatively stable, the resin is relatively narrow in molecular weight, the organic chlorine content is low, the cured coating crosslink density is high, and the voltage resistance is good. In the preparation of battery shell powder with excellent insulation performance, bisphenol A epoxy resins synthesized by two-step method are recommended, and the chlorine content is low and the molecular weight is narrow.
When curing agents are used in small quantities, the coating's pressure and physical properties are relatively poor, and the electrolyte resistance is poor due to incomplete system curing, coating impact performance and other poor performance. However, when the curing agent dosage exceeds a certain degree, not only because of the increase in cost but also because of the speed of gel and affect the impact of the coating. The technical indicators of BPA epoxy resin produced by different manufacturers are different, and the amount of curing agent in the formula needs to be verified by theoretical calculation.
in catalysts, mides can significantly reduce the coating film temperature or shorten the coating curing time. In powder coating, the cross-link reaction temperature of the system can be greatly reduced, and the cross-linking density of the coating can be increased, saving reaction time to make the coating curing more fully.
In the addition of pigments, the electrical insulation performance of nicosium sulfate is worse than that of calcium carbonate, but the absorption of calcium carbonate will lead to a relatively large amount of oil absorption of the coating level performance is not good, and calcium carbonate in the production process will bring a large number of impurities, will also affect the electrical insulation performance. The most commonly used insulation powder is silicon micro-powder, and the higher dielectomy constant makes it the most widely used in insulation powder.
electro-insulated powder coating on the insulation of the coating pressure resistance requirements are high, in the raw material selection process must be strictly screened, in accordance with customer standards to determine the appropriate formula, control the mixing of impurities in the production process, to obtain excellent heat resistance, excellent corrosion resistance and excellent electrical insulation performance of the powder coating.