CS258712B1

CS258712B1 - Insulated electroconductive core

Info

Publication number: CS258712B1
Application number: CS863366A
Authority: CS
Inventors: Jozef Horvath
Original assignee: Jozef Horvath
Priority date: 1986-05-08
Filing date: 1986-05-08
Publication date: 1988-09-16
Also published as: CS336686A1

Abstract

Riešenie sa týká odboru elektrotechniky. Podstatou riešenia je izolácia elektrovodivého jadra přechodem jadra cez taveninu bezrczpúšťadlovej termoreaktívnej živice. Vysokoviskózna tavenina má funkciu podlepovacieho laku, na ktorý sa opradie vrstva sklenej priadze. Riešenie je možné využiť na izolovanie jadra s kruhovým prierezom ako aj na izolovanie vodičov s plochým profilom.The solution concerns the department of electrical engineering. The essence of the solution is the insulation of the electrically conductive core by passing the core through a melt of solvent-free thermoreactive resin. The high-viscosity melt has the function of an adhesive varnish on which a layer of glass yarn is spun. The solution can be used to insulate a core with a circular cross-section as well as to insulate conductors with a flat profile.

Description

238712

It is an object of the present invention to provide an insulated electro-conductive core with fiberglass backing on a bonding lacquer layer. The purpose of the invention is to obtain an electroconductive core with good electroinsulating properties of convenient economic and environmental conditions.

Increasing performance and reducing the size of electrical machines requires electrical insulation materials of higher temperature classes with good mechanical and electrical properties. In the case of these properties, the good shear is pre-impregnated with glass yarn. Glass yarn insulation is glued to the bare or insulated core by tapping varnish and the surface varnished.

Of the glass-lined conductors, the most known are the types in which the bare core is insulated with taped and surface-lacquered glass yarn. Low viscosity solvent-based electro-insulating lacquers, typically in the range of 100-300 mPa, are used to bond the glass fiber. s at 20 ° C. The core-wetted with this varnish is lined with a single-or-several-fold glass yarn and is pressed twice through the surface e-lacquer varnish. This method of isolation is done in one or more technological operations. In modern single-purpose devices, the conductive cores are insulated such that one calibrated layer of bonding varnish is baked in the furnace, then wetted again in a tomed-on varnish by glazing and coated with surface varnish. In the case of the conductors thus produced, the glass yarn is pressed into the core or the core, due to the low viscosity of the bonding lacquer. excess varnish will soak up the yarn and fill it with gaps, or leak to the surface of the fencing. The superficial lactacto no longer functions and only contributes to the impregnation of the glass yarn. The conductor tests of the two types show that the first type conductors have lower cross-link voltage values as the second type conductors, even at approximately the same isolation gain. An increase in the values of the breaker-type tensioners of the second type is caused by one layer of cured lacquer. However, some devices do not allow this method of producing glass-glazed conductors.

The drawbacks of the prior art conductor insulation method are eliminated by the solution of the invention, which consists in the use of a melt of a teroreactive resin as a bonding layer. The resin contains a small amount of solvent, not more than 20%, and non-tacky at ambient temperature.

Resin melt whose viscosity at pra-mPa. is applied to a circular or profiled core conductor heated to a temperature close to 100 DEG to 180 DEG C. is 1000 to 8,000 bar working temperature of the melt and adjusted through the calibers to the prescribed deposition depth. In the next step, the still molten layer of lime is covered with glass yarn in one or more layers. Since the viscosity of the molten resin is high, the yarn to the conductor core is not extruded during the backing, and a layer of bonding resin is formed between the backing and the core, which functions as an insulating layer.

Furthermore, the glass backing layer is typically coated with two or more layers of low viscosity solvent surface varnish. The first surface lacquer layer is impregnated with a glass of yarn, further layers already fulfill their surface lacquer function. After each passage of the surface-lactate conductor, this is cured in an oven, wherein the layer of resilient resin is cured either after glazing with glass yarn or in one working process simultaneously with the first surface-coating layer. In the event that the melt-insulated electroconductive core of the present invention cools the ambient temperature before glazing with glass yarn, it wraps such pre-coated core onto the intermediate diameter coils. The coils with this semi-finished product can be stored for later use with glass yarn and topcoat overcoat.

The following examples and the results of practical verification tests for the isolation of copper strips as well as circular cross-section conductors demonstrate the advantages of the solution according to the invention. EXAMPLE 1 The core was isolated by a conventional solvent lacquer procedure containing 40% of a drier with a viscosity of 120 mPa. s at 20 ° C, glazed with glass yarn in one or more layers and overpainted two or more times with surface solvent lacquer in one or more processing operations. EXAMPLE 2 The core is insulated with a calibrated undercoat layer as in Example 1, cured in an oven and rewetted with the same lacquer and then lined with glass yarn and overcoated with surface varnish. Example 3

On. 1.5 x 4 mm copper strip, 118 ° C preheated at 3 m / min. and at a temperature of 130 ° C, a layer of high-concentrated esterimide resin was deposited in a temperature grade F of 85 percent nonvolatiles with a viscosity of 4,200 mPa. at 130 ° C and a dipping point of 86 ° C. The strip with the resin layer was left to stand at ambient temperature and then fused in a single layer with glass yarn. Thereafter, the conductor was cured in a 6,000 mm long 258712 furnace

S β at T = 380 ° C; T2-450 ° C; T3 = = 580 ° C at 5 m / min. After curing, the conductor was tripled with polyesterside varnish of heat class F with a content of 34 percent by weight of non-volatile substances and an outflow time of 120 seconds.

The 1.4>: 4.5 mm pre-heated copper band at 128 ° C is at 3m / min. applied a layer of high-concentration esterimide resin in cresol (H-grade) whose viscosity at 130 ° C was 2500 mPa. The non-volatile content was 82 percent by weight; popping point 62 ° C. The conductor was fed in a single melt-deposited single-glass operation with a glass sheet and subsequently coated with a surface polyester lacquer of temperature class H at temperatures as in Example 3 at a flow rate of 6 m / min. The cushioning resin was cured at the same time as the first coating of the surface varnish, and the total absorber was overcoated with three layers of surface varnish. Example 5

To emphasize the advantages of the conductors insulated by the method of the invention, the conductors according to the method of Example 1 are produced, but with double glazing with a glass sheet. Example 6

The conductor produced according to Example 2, with two-fold glazing with glass yarn.

The characteristics of the wires according to Examples 1 to 6 are given in the table.

Table

Property Example Measured Values 1 2 3 4 5 6 Increment Thickness 0.11 0.16 0.15 0.19 0.30 0.33 Insulation, mm Width 0.11 0.12 0.11 0.12 0.23 0 , 22 Dimension Cu mm 1x5 1x5 1,5x4 1,4x4,5 1x5 1x5 core, Break-through X 450 720 830 860 680 910 V-min. 420 680 800 800 580 890 nom, 180 ° C x 380 650 590 680 300 720 Fifth min. 300 630 580 640 280 660 Nicky and heat-200 ° C x 280 620 570 650 320 760 nom load 3s min. 240 600 500 580 300 740 180 ° C x 350 690 590 640 520 720 5 min min. 300 650 550 560 500 690 200 ° C x 320 640 570 640 420 680 5 sec min. 260 600 560 560 380 600

Explanations: x— mean value min. - minimum value š - nominal wire width (together with the number indicates the wire bend on the high around the bar diameter multiplied by the wire width)

The conductors of Examples 5 and 6 have significant higher increments of insulation than previous conductors, but the conductor penetration values do not match that.

The electroconductive core of the present invention has improved electrical and mechanical properties, with the further advantage of saving solvents and diluents and hence the cost of the lacquer, using environmentally-friendly technology as the spraying varnish is not sprayed due to its high viscosity. The adhesion of the insulation is the same as that of the isolators isolated by the classical process.

Claims

258712 BEFORE MET

An insulated core with a glass yarn braid layer on a backing varnish layer, characterized in that a core of a solvent-free ter-meactive resin with a dry matter content of above 80% by weight, which is rigid, non-sticky at normal temperature, is present on the core. and at a working temperature of 100 to 180 ° C, a viscosity of 1000 to 8000 mPa. with.

2. A method for producing an insulated electro-core according to claim 1, wherein the preheated core is passed through a solvent-free thermoreactive resin having a dry matter content of over 80 percent by weight with a viscosity of 1000 to 8,000 mPa. with a working temperature of 100 to 180 [deg.] C., subsequently lined with a glass yarn in one or more layers, each layer is varnished with a low viscosity solvent coating lacquer and cured after each additional layer has been applied. Severografia, n. P. Plant 7, Most Price 2.40 KCs