Why does the tape curl after high frequency transformer is dipped in paint

High frequency transformer is always immersed in insulating paint, oven out, a lot of tape on the warping, uu9.8 also has the same tape warping phenomenon, ask for advice! Common mode EE12, wire diameter sensitivity 0.21, 30mh, customer requirements are strict, can't leak copper wire, automatic tape wrapping machine is difficult to realize, so manual wrapping, but also for empty!

Answer 1: 1, the adhesive tape is not enough, there is already a situation of warping before dipping, and there is a large area of warping after dipping. Need to choose a better adhesive tape, or check the tape storage time is not too long. 2. The proportion of paint should not be too thin. 3. Generally speaking, the technology of transformer is in place, so there is no need to vacuumize the paint. We put it into the paint and take it out. 4. The magnetic core is wrapped with a wider tape, which is also a way to deal with the current situation. 5. Dispensing, in the magnetic core magnetic core and wire package of the joint surface of the dispensing treatment.

The second answer: whether the tape will be warped after dipping is not only related to the stickiness of the tape, weather and whether there is dirt on the surface of the tape, but also related to the operation method. It is better to cut the tape 2-3mm below the middle of the side of the magnetic core and wire package. The concentration of standing water, soaking time, baking temperature and baking time will have an adverse effect on this process.

Answer 3: this kind of problem of building owners is more common in the case of vacuum impregnation of narrow non 3M tape. It is mainly caused by the following reasons: 1. The adhesive tape is not strong, the adhesive tape is narrow, and the adhesive force with copper wire and inner ring tape is not strong. 2. When wrapping the tape, the pulling force is too large and the wrapping is too tight. 3. The end position of the tape is too high, and the cutting position of the tape is not covered by the magnetic core. 4. The winding body is thin and the distance between the magnetic core and the winding body is large. 5. During vacuum impregnation, there is varnish in between the layers of the tape, which reduces the viscosity of the tape. The improvement methods are also aimed at the above problems: 1. Replace 3M tape of the same specification with strong self-adhesive property (the unit price is high, which can be used when it is not quoted at the initial stage of development). 2. Adjust the tape tension of winding machine to keep the tape tension close to 0. 3. The fracture of the tape must exceed the lower edge of the assembled magnetic core (2 / 3 of the winding body side). 4. Slightly adjust and increase the wire diameter to make the winding body full and ensure that the magnetic core can just jam the tape. 5. The vacuum impregnation is canceled and the natural impregnation is used instead (the inductance of this kind of product decreases greatly during vacuum impregnation, which is easy to cause batch defects and waste). 6. When the above cannot be adjusted, use this method: use a 200 ℃ constant temperature electric iron to slightly iron the section of the tape to increase the viscosity. The defect rate can be reduced by 99%.