Insulating tape and method of its manufacture
(57) Abstract:The invention relates to insulating materials and methods for their manufacture. According to the invention of insulating tape consists of one or more layers of glass and one or more layers of mica. Glass filament fabrics have a protective coating of resin or varnish. Cell fiberglass filled resin with a filler containing microscopically small particles with conductivity greater than that of the resin. Duct tape has higher conductivity, mechanical strength and heat resistance. 2 S. and 3 C.p. f-crystals, 2 Il. Scope.The invention relates to an insulating tape containing at least one layer of mica and one layer of fabric, with a significant degree of cell tissue, consisting of threads filled with resin with a filler containing microscopically small particles with larger than particles of the resin, thermal conductivity.The invention relates further to a method of manufacturing such an insulating tape.Large electrical machines with a cooled indirectly by a stationary winding is very demanding to thermal insulation of the winding. As the warmth, who is a metallic environment, insulation should not have some random thickness, on the other hand, must be kept at the machines high voltage with a rated voltage of 16 kV certain minimum thickness of the main insulation. Hence the great need for insulating materials, durable against high breakdown voltage and at the same time with good conductivity.Basic insulation stationary winding according to US-A-4 806 806 or similar content EP-A-0 266 602 consists of layered insulating tape wound in multiple layers around a bundle of wires. Insulating tape provided with either of the above-mentioned impregnation resin, or a resin was applied only after winding an insulating tape. Herself insulating tape consists of several thin mica layers and hard layers of fiberglass. To improve thermal conductivity in the impregnating resin was added inorganic filler with good thermal conductivity, for example of nitrogen, aluminum, and nitrogen silicon, aluminum oxide magnesium oxide, beryllium oxide or silicon carbide with a particle size of 0.1 to 15 μm, and the coefficient of execution is at least 90 weight percent in the cells of fiberglass.In US-A-4 806 806 uke is the outer coat of the mixture, on the other hand, decreases the risk of damage to sensitive mica coating. However, these inventors have lost sight of the fact that the particles of filler mechanically destroy largely filament fiberglass. These threads of the fabric are composed of thin and very thin fibers, which are twisted with each other, and the diameter of the fibers corresponds to the size of the filler particles. These particles with sharp edges can damage the threads of the fabric during the winding, especially in the further processes of pressing, so that the glass can no longer perform or may perform insufficient function of the media and who consolidates.The basis of the invention is the task of making an insulating tape having a relatively high conductivity without compromising its electrical insulating properties and its durability, and also describes a method of manufacturing such a tape.This problem is solved in accordance with the invention, so that the threads of the fabric have a protective layer of resin or varnish, which covers mostly only thread and not fill in this cell, tissue, and percentage of mica in relation to the filler in a weight percentage greater than or at least the coy, thermal and mechanical durability. As an impregnating resin mixed with filler, is mostly only between the tissue cells and not in the mica layer, electric (breakdown) insulation strength even increases. The liquid particles having sharp edges, cannot incise fine filaments or fibers that make up the filament, so that the mechanical strength at the time of manufacture of the tape and its application to multi-wire conductor, and during further operation is also stored. Good thermal coupling of the adjacent mica layers - they are good teploprovodnymi - is ensured by the application of an impregnating resin, which is also a good conductor of heat.Manufacture of insulating tape is such that the threads of the fabric is first coated with a layer of flowable resin, preferably epoxy resin, so that in the main thread cause the protective layer, however, the resin does not fill the cell tissue. After that, the filler in the form of a binding resin applied to the tissue by the method of calendering.Examples of carrying out the invention, and also achieved when the benefits are explained further in detail using the drawing.Nastojashi isolated from each other separate wires; in Fig. 2 is a greatly enlarged section 1 explaining the structure of the main insulation.According Fig. 1 stranded conductor electrical machine consists of many isolated from each other separate wires 1, made in accordance with insulation 2 for individual wires. Separate the wires 1, collected in one bundle of wires, surrounded by basic insulation 3.In highly magnified cutout according to Fig. 2 shows the multilayer structure of the main insulation, consisting of many intertwined insulation tapes 41, 42, 43, 44.Each insulating tape 41, 42, 43, 44 ... has two layers: the mica layer 5 and the layer of glass 6. Cell fiberglass, with the warp threads 7a and weft threads 7b, i.e., the space between the two adjacent glass filaments of glass 6, the filled resin 8, to which was added a powder of oxide of metal 9 with a particle size of from 0.1 to 15 μm. Mica layers 5, in contrast, contain practically no powder of oxide of the metal.In this respect, the structure of the insulating tape complies with the above in patent US-A-4 806 806.According to the invention, the warp threads 7a and weft threads 7b fiberglass is provided with a protective layer 10, the thickness that the layer 10 prevents the cut glass fibers, consisting of thin optical fibers 11. The protective layer 10 is preferably made of elastic epoxy resin, which is compatible with the subsequent impregnating resin and also moisturizes glass filament 7a and 7b and the optical fiber 11.The preferred embodiment of the claimed insulating tape has the following typical parameters:
The thickness of the layer of fiberglass 6 - 50 µm
The thickness of the mica layer 5 - 100 µm
The thickness of the warp and weft threads 25 μm
The thickness of the fibers or filaments of 8 μm
The thickness of the protective layer 10 is 5 μm
The particle size of the powder of aluminum oxide - 3 μm
Pungent resin 8 - Epoxy resin
Instead of fiberglass can be applied to so-called mixed fabric with warp threads 7a of the glass threads and weft threads 7b of synthetic material, for example a complex of the polyester.In the manufacture of insulating tape, first thread 7 fiberglass 6 covered with a flowable resin, preferably epoxy resin, so mostly covered with a protective layer only yarn, resin, however, does not fill the cell tissue. After that, the filler (resin and a powder of metal oxide) is applied to the fiberglass method of calendering. Finally, Armenia least one layer of mica and one layer of fabric, the cells between the threads which are filled with a resin with a filler containing microscopically small particles with a higher thermal conductivity than the resin particles, characterized in that the threads of the fabric have a protective layer of resin or varnish, and the cells of the tissue are left blank, and the fact that the proportion of mica in comparison with the filler in a weight percentage greater than or at least equal to 1.2. Tape p. 1, characterized in that the filler consists of at least one component selected from the group consisting of nitrogen boron, nitrogen, aluminum, nitrogen and silicon, aluminum oxide, magnesium oxide, beryllium oxide or silicon carbide, and the particle size of the filler is from 0.1 to 15 microns.3. Tape under item 1 or 2, characterized in that the protective layer is made of a resin or varnish and has a thickness of from 1 to 10 microns.4. The tape according to any one of paragraphs. 1-3, characterized in that the fabric is fiberglass or mixed fabric with a basis of glass fibers and the weft thread from a synthetic material, for example a complex of the polyester.5. A method of manufacturing an insulating tape under item 1, characterized in that the threads of the fabric is first coated with a layer of flowable resin, preferably epoxy on the fabric causing the resin with the filler and eventually the thus treated fabric glue with mica layer.
FIELD: electrical engineering; insulating materials.
SUBSTANCE: proposed method for manufacturing insulating materials used in insulators and surge limiters, as well as in manufacturing pipelines, bushes, shells, bearings, wiring insulation of cases includes some additional operations; pre-drying, impregnation, and final drying of prepreg are effected in vacuum chamber and arbor is preheated before prepreg rolling up. Electric strength of prepreg produced by this method is 3.7 to 4.5 kV/mm which is much higher than that of known tubular prepregs.
EFFECT: enhanced quality of fabric surface pre-treatment, improved conditions of impregnation process.
FIELD: the invention describes the method for manufacture of a high-voltage insulator with an elongated central solid or hollow body, plastic casing and one or several plastic sheds.
SUBSTANCE: the method consists of several stager: the casing from plastic is obtained by means of casting or extrusion for the solid or hollow body; the sheds are formed from plastic; the plastic of the casing and/or the plastic of the sheds is partially stitched, and whenever necessary, the incompletely stitched plastic of the casing or shed are stitched completely, the shed is fastened on the specified place on the casing, and the obtained blank of the high-voltage insulator is stitched completely. The silicon rubber contains at least two stitching catalysts reacting at various temperatures, or at least two inhibitors suppressing the reacting of connection at various temperatures.
EFFECT: facilitated procedure.
28 cl, 3 dwg
FIELD: manufacture of column-shaped high-voltage bushing insulators.
SUBSTANCE: proposed bushing insulator has symmetrical hollow cylindrical external insulator 1 with lead-through head 2 supported by one of its butt-ends and designed for connection to high-voltage supply. Resting on opposite end of insulator is lead-through base 3 designed for connection to ground potential. Proposed method involves sequential fitting of lead-through base 3, external insulator 1, and lead-through head 2 on drawing frame 5; lead-through base 3 rests in this case on insulating case 6. Lead-through base 3 and lead-through head 2 are tightly fitted to one another through drawing frame 5 that mounts insulating case 6. Clamping member 21 made for shifting in axial direction is installed on flange 22 of lead-through head 2 prior to fitting the latter on drawing frame 5; head flange 22 and clamping member 21 are pressed against one another to produce pre-tensioning force. During next fitting of pre-tensioned lead-through head 2 clamping member 21 is secured on end of drawing frame 5 passed through insulator 1, and then clamping member 21 is taken off head flange 22 to form negative allowance.
EFFECT: enhanced economic efficiency in manufacturing high-voltage bushing insulator.
7 cl, 2 dwg
FIELD: chemical industry; methods and devices for manufacture of the electric plastic insulators.
SUBSTANCE: the invention is pertaining to the field of manufacture of the electric plastic insulators. The device for manufacture of electric plastic insulator contains the mould for manufacture of the insulating screens, which may be installed concentrically around the vertically located core or the hollow core. The mould has the field arranged below in the axial direction and fitting to the core around it or to the hollow core and the arranged above in an axial direction area, which is extending in radial direction with respect to the field arranged below in the axial direction and may be made according to the form of the being produced insulating screen. Between the end of the arranged below area in the axial direction and the upper end of the mould there is at least one injecting channel for injection of the liquid synthetic material under pressure. The method of manufacture of the electric plastic insulator is realized in several steps: a) the mold is installed in the preset axial position; b) form the a sealing coupling between the core and the mould; c)inject the liquid synthetic material under the heightened pressure with respect to the pressure of the environment; d) harden the synthetic material in the mould; e) remove the sealing joint; f) transfer the mould downwards on the preset spacing interval; h)repeat the steps b) - f) up to production of the required number of the insulating screens. The invention ensures the shorten duration of the material molding and curing, that reduces the production time of the insulators.
EFFECT: the invention ensures the shorten duration of the material molding and curing, that reduces the production time of the insulators.
12 cl, 3 dwg
FIELD: electrical engineering.
SUBSTANCE: proposed method for producing spiral skirt 2 for high-voltage insulator 1 allows for manufacture of actually cylindrical backing 3, extruder 10 incorporating extrusion head 11 that governs extrusion direction A, makes use of extruder 10 for extruding insulator skirt 2 and application of the latter onto backing 3 while rotating this backing relative to extrusion head 11. Novelty is that extrusion direction A actually coincides with longitudinal axis of backing 3; the latter is fed through extrusion head 11. Skirt manufactured by this method can be used for high-voltage insulators, high-voltage lightning arresters, or high-voltage cable entries.
EFFECT: ability of producing high-voltage parts having relatively small diameter.
12 cl, 3 dwg
FIELD: electrical engineering; polymeric insulators and their manufacturing process.
SUBSTANCE: proposed composite insulator manufacturing process includes skeleton fixation in winding mechanism that rotates it about longitudinal axis at the same time moving skeleton along its axis, production of profiled band from T-section silicone rubber band by means of extruder, installation of fin in a spaced relation between turns followed by its rolling-on. Skeleton rotating and moving mechanism is inclined relative to extruder through angle equal to that of fin inclination. Fin is thickened at least on one end of base and this end is flattened in the course of rolling to fill up clearance between adjacent turns. Then part obtained is polymerized and wiring hardware is mounted thereon.
EFFECT: facilitated manufacture, improved termination of silicone finning edge.
1 cl, 2 dwg
FIELD: electrical engineering; electrical insulators.
SUBSTANCE: protective shell is manufactured from two parts: a tube (a hose) slid over a rod or a pipe made of electrically insulating material and glued to said rod/pipe, and fins that can be glued over said tube (hose) at any intervals allowing for obtaining any leakage path length.
EFFECT: improvement of reliability and cost-effectiveness of polymer insulators.
FIELD: electrical engineering.
SUBSTANCE: invention relates to electrical engineering, particularly to the method of making high-voltage lead terminals. Channels are made in the electrically conducting element of a lead terminal, providing for access of the impregnating compound to inner layers of electric insulating material, and on the end sections, flanges are attached, which boarder the area where electric insulating material is put. After winding electric insulating material, the lead terminal is thermally processed and put into an elastic sealed sheath, on which nipple passages to its inner cavity are put, uniformly distributed along the sheath. The lead terminal is then put into an impregnating chamber, thereby joining channels in the electrically conducting element and the nipple passages with the vacuum-pressure impregnating system. Further impregnation and insulation are done at high pressure of neutral liquid in the impregnating chamber and the compound inside channels in the electrically conducting element. The neutral liquid is heated and the lead terminal is baked.
EFFECT: increased reliability and service life of lead terminals.
10 cl, 2 dwg
FIELD: electric engineering.
SUBSTANCE: invention is related to bushing insulator for supply of electric current and/or voltage. Bushing insulator (1) for supply of electric current and/or voltage via grounded plate (2), comprising axisymmetric insulating bushing (3), which surrounds central electric conductor (4). Bushing insulator has sealing part (5) for gas/liquid sealing between conductor and insulating bushing, which represents insulating paper impregnated with resin. Insulator is equipped with compressing sealing element (6), which serves as gas/liquid sealing between conductor and insulating bushing and combined with insulating bushing. Method for manufacturing of bushing insulator comprises impregnation of insulating bushing with hardening material and giving monolith shape in process of hardening with shrinkage. Sealing part is placed on part of conductor axial conductor length between insulating bushing and conductor prior to winding of insulating material.
EFFECT: invention gives possibility to avoid concentration of mechanical stresses at external edge of insulating bushing.
29 cl, 6 dwg