Coil impregnation process

zbz0529

Coil impregnation process [Copy link]

At present, the commonly used paints for coil impregnation are H30-2 epoxy resin paint and H86-2 solvent-free paint. In actual application, these two paints have their own strengths and cannot completely replace each other. They are suitable for different situations. How to choose? The following is a comparison of the use of these two impregnation paints.

(1) Comparison of processing technology

H86-2: The curing cycle of impregnation is relatively fast. When the curing temperature is around 120-140℃, the curing time is about 14 hours, and intermittent curing is allowed. It is suitable for small batch production or when there are few people and shifts are not possible.

H30-2: The curing time of impregnation is long, the curing temperature is 120℃, and the curing time is about 50 hours. The main reason is that once the paint forms a paint film on the outer surface of the coil, it is difficult to cure inside. Especially when there are many layers of coils, this kind of problem is more likely to occur. The curing must be carried out in a vacuum state, and it requires continuous operation without interruption. It is suitable for mass production.

(2) Comparison of product appearance quality

H86-2: This paint has a high solid content, about 80%. The outer dimensions of the coil increase slightly after impregnation. Therefore, there are requirements for the space factor of the coil. The surface gloss of the coil is poor.

H30-2: The coil after impregnation with this paint has a glossy appearance. After impregnation and curing, the outer dimensions shrink slightly compared to before impregnation, but basically maintain the original dimensions, and can make the original outer insulation tightly bonded to the surface of the wire, which is beneficial for coils with a higher space factor.

(3) Comparison of intrinsic quality

　　H86-2: The acid value is high, so it is not suitable for coils wound with copper skin. However, under normal conditions, the insulation strength is higher than that of coils impregnated with H30-2 paint.

　　H30-2: Low acid value, suitable for all kinds of wires and copper sheets.

(4) Comprehensive comparison in other aspects

　　H86-2: This paint has strong adhesion and is hard after curing. The residual paint on the lead-out welding piece is difficult to remove, which increases the workload of assembly. At the same time, it also increases the requirements for the occupancy factor of the previous winding process. However, it has the advantages of high temperature resistance (180℃) and can be used for core dipping.

　　H30-2: After curing, the paint is relatively soft and easy to process in the subsequent process. The residual paint on the lead-out welding piece is easy to remove and there is no special requirement for the previous process. The paint can also be used repeatedly and is not easy to fail.

　　In short, how to choose H86-2 solvent-free paint and H30-2 epoxy resin paint can be considered as follows: if only the coil quality is considered, H30-2 epoxy resin paint should be preferred, it has a low curing temperature (the lowest can be reduced to 100°C), a wide range of applications, a soft texture, is easy to wind and assemble, and it is also easier to ensure the impregnation quality; if it is considered from an economic and practical point of view, H86-2 solvent-free paint can not only impregnate the coil, but also the iron core, and has the advantages of high temperature resistance, good bonding strength, short curing time, and intermittent operation.