CS243181B1 - Mica tape with the possibility of additional impregnation on the wire - Google Patents

Abstract

The aim of the invention is to make a strip insulator from fine mica, glued on one or both sides to a varnished electrotechnical glass fabric, usually with a weight of up to 50 g/m^, intended for insulating electrical machines, especially coils, both in the straight groove part and in the curved parts - the coil faces, with the possibility of subsequent impregnation of the wound insulation. The invention makes it possible to eliminate the previous shortcomings in that there is a significant saving of foreign exchange for expensive packaged split mica and to eliminate unpleasant manual work. Fine mica also allows the penetration of the impregnator into all cavities, thereby achieving high homogeneity of the insulation. Modifications to the machinery make it possible to produce mica tape from fine mica with very good insulating properties. Fine mica itself has lower dielectric properties, but in the arrangement according to the invention, better resulting properties are achieved, because there is more perfect impregnation of the insulation, less leakage of the binder and thus better homogeneity and quality of the insulation. The invention enables the production of single-layer and multi-layer mica tape, without manual laying of mica.

Description

The invention relates to an insulator intended for insulating electrical machines, in particular coils, both in the straight groove part and in the curved parts - coil ends, with the possibility of subsequent impregnation of the wound insulation.

The object of the invention is to make the production of the insulator more efficient in terms of reducing labor, utilizing fine mica and allowing subsequent good impregnability, thereby achieving a high homogeneity of the insulation and thus a better quality of the insulation.

The prior art method for the production of mica tape consists in the application of an electrotechnical glass fabric with a thickness of 0.035 mm, with a basis weight of about 30 g / m, and a thickness of 0.040 mm, respectively.

2 with a basis weight of approx. 35 g / m 2, hand-streaked mica of 30 to 65 cm (in some cases over 65 cm) is laid so that the mica slices overlap each other. After covering the glass fabric with mica slices, it passes as a continuous belt in a horizontal position through a lacquer slot where both the glass fabric and the mica slices are coated with an electroinsulating binder.

Then the belt passes through a drier and after it is wound into a roll as a blank, which is cut into a tape of different widths on a disk cutter. The cut tape is wound into the reels in the required length and is tightened appropriately so that the reels are not deformed during further handling, especially when insulating the conductors.

The tape is produced with various binders, depending on the required thermal class of insulation, most often in the heartbeat. class B, F and H (not more than 180 ° C).

The technical disadvantages of the mica tapes thus produced are that the mica to be chipped must be laid by hand, and that exposed mica sites often occur. From the economic point of view, the main disadvantage is expensive chipped mica and high labor intensity. In recent years, workers do not want to produce products where mica has to be laid by hand.

These disadvantages are solved by the invention, which is based on the use of fine mica for the production of mica tape instead of large-size chipped mica. In order to do this, the existing production equipment needs to be adapted appropriately to enable the mechanization of the laying of this fine mica - see Figures 1 and 2.

The basic technical effect is that the use of fine mica results in a better saturation of the binder insulation after winding the tape on the wire and pressing it. By pressing the insulated conductor, the binder discharge is less, because tiny mica forms a better barrier against binder leakage. This gives the insulation greater homogeneity. In addition, mica tape can be made with low binder content and filled with conductor insulation with an impregnant.

This achieves the highest degree of homogeneity of the insulation with high dielectric properties.

He did

At the production plant, the E 66-30-30 g / m 2 glass fabric is unwound from a roll, passes through a paint tray where it is coated with an acetone epoxy binder (Alkylepoxy F) with a viscosity of 15 seconds, then passes through a mica container 8 - see Fig. 1 , where it is automatically covered on both sides with a small mica of size up to six cm 6. In order to prevent the mica from stuffing in the container, it is provided with rollers with vanes on the surface 2. The rollers are rotated by means of a motor.

Due to the mica particles being thrown away, several layers of mica are undesirably attached to each other. and outside of it, to install a wiper device for excess mica in the form of felt gauge strips. Rectifier rollers 6 are located below the mica container. Wiped excess mica falls back into the tank. The blank thus produced is passed through a drier, after which it is wound into rolls and then cut into rolls in a conventional manner.

Example 2

On a production machine, the E55-40 - 40 g / m 2 glass fabric is unwound from a roll, passes through a paint tray where it is coated with toluene silicone binder (Lukosil 200), viscosity 14 s, and then passes through a mica container 2 '. where she sits on both sides herself nale2 small mica size up to six cm 6.

The mica reservoir is equipped with fluff rollers 2. Above the reservoir there are calibration brushes 2 · Wiped excess mica falls back into the reservoir. Rectifier rollers 2 are positioned below the container. The preform thus produced is passed through an oven in order to evaporate most of the solvents, winded into rolls behind it and then cut into strips in the usual manner.

Example 3

On the production machine, the E55-40 - 40 g / m 2 glass fabric is unwound from a roll, passes through a paint tray where it is coated with acetone epoxy novolac binder (DEN 438 with a latent catalyst of 100 parts resin: 3 parts catalyst) of viscosity 12 s, after which it passes through the mica container 2 - see Fig. 1, where it adheres small mica on both sides, sized up to six cm 6.

The mica reservoir is provided with fluff rollers 2. Above the reservoir there is a calibration device 2 · The wiped excess mica falls back into the reservoir. Rectifier rollers 2 are positioned below the container. The blank thus produced is passed through an oven in order to evaporate the solvents, after which they are rolled into rolls and then cut into strips in the usual manner.

Example 4

On the production machine, the E66-30 - 30 g / m 5 glass fabric is unwound from a roll, passes through a paint tray where it is lacquered with toluene esterimide binder (elmotherm F 55 T), with a viscosity of 16 sec. 2, where he packs one-sided small mica size up to six cm 6.

The reservoir is equipped with a fluffing roller 2. Due to the adhesion of the mica particles, they adhere in several layers on top of each other, and therefore a wiper device 2 must be installed above the reservoir. Rectifier rollers 2 are located under the hopper 2 ·

The blank thus produced is passed through a drier, after which it is wound into rolls and then cut into rolls in a conventional manner.

Claims (2)

SUBJECT OF THE INVENTION Mica tape with the possibility of additional impregnation on a conductor consisting of a single layer of electrotechnical glass fabric of weaker thickness, preferably 30 to 40 g / m 2, of electrical insulating binder and mica sheets, characterized in that the mica sheets have an area dimension of at most 6 cm 2. 2. A method for the production of mica tape with the possibility of additional impregnation on a conductor according to claim 1, characterized in that the impregnated adhering glass fabric is guided perpendicularly from below to the mica container, where it adheres itself to one or both sides of the mica.