3.8.1 The E-grade insulation of the phenolic adhesive paper tube is made of single-sided adhesive paper rolled by a tube reeling machine.The rolling process is: the adhesive paper is rolled onto the tube core, and the adhesive on the adhesive paper is fused by heating and pressurizing, and it is initially cured.After the roll reaches the specified thickness, bake it together with the die to make it completely cured!The adhesive paper tube after the pipe is removed shall be processed according to the required size of the drawing.In order to prevent moisture, you can dip phenolic resin paint or 1032 paint twice

3.8.2 Epoxy glass cloth tube

It is grade B-F insulation and is used as a support cylinder for the winding of a B-F dry transformer or a guard cylinder for a switch.The epoxy glass cloth tube is rolled with epoxy glass cloth.The process method is basically the same as that of rolling a phenolic tape tube.The glass cloth used in epoxy glass cloth should be alkali-free glass cloth, that is, the alkali content is less than

0.8%, otherwise it will affect its electrical performance.

3.8.3 Glass fiber reinforced plastic tube

The glass fiber reinforced plastic tube is wound at an angle with the axis after the cluster glass roving is impregnated with resin.There is a heating device in the winding machine, and the initial curing is achieved. After the required thickness is reached, the rotation curing is carried out to prevent the loss of glue.

The heat-resistant grades of glass fiber reinforced plastic cylinders are Grade B, Grade F and Grade H.Its temperature resistance level is mainly determined by the temperature resistance level of the resin used.

3.8.4 Enclosed cardboard tube

Advantages of phenolic adhesive paper tube: accurate size, good mechanical strength and not susceptible to moisture, etc., But in the oil change, its oil absorption rate is poor, and it is difficult to ensure that there are no remaining air bubbles inside.The so-called enclosed cardboard tube is a cardboard tube made of multi-layer cardboard rolls.

3.8.5 cardboard tube

Cardboard tubes are also called thick cardboard tubes.It is mainly used as a large transformer winding skeleton cylinder.Its electrical properties and oil absorption rate are much better than that of phenolic paper tubes.

The thickness of the cardboard used is generally 4, 5, and 6mm, and T4 cardboard is used.A slope is milled into a slope by an edge milling machine at the lap joint, and the bevel is deburring and then thermally bonded.

3.9 Corrugated cardboard

In the oil board gap structure composed of multi-layer paper tubes of high-voltage transformers, corrugated cardboard can be used instead of struts to form an oil gap.This kind of insulation structure can save insulation materials on the basis of ensuring insulation properties.

There are two types of intermittent large corrugated board and continuous small corrugated board.

3.10 Electrical laminate

Electrical laminate is an insulating material with a layered structure made of paper, cloth and wooden veneer as the substrate, dipped in different adhesives, and hot-pressed or rolled.

Laminated products mainly include laminated panels, laminated wood, laminated tubes, rods, capacitive ceramic die cores and other special profiles.The performance of the laminate depends on the nature of the substrate and adhesive and its molding process.

3.10.1 Laminated glass cloth board

It is made of alkali-free glass cloth treated with silane as the substrate, which is dipped, baked, and hot pressed.According to the different resins immersed, it can be divided into glass cloth plates of different heat-resistant grades.Commonly used in transformer products are: epoxy glass cloth plate, silicone glass cloth plate, Shuangma glass cloth plate and modified diphenylether glass cloth plate.

3.10.1.1

The adhesive resin used in epoxy glass cloth board (3240) is epoxy phenolic resin.It has high mechanical strength, electrical properties, good heat and moisture resistance, and good machinability. The heat resistance grade belongs to B and F grades.Mainly used for air gap struts, air gap pads, iron yoke pads and partitions of Class B and F dry transformers, etc.

3.10.1.2 Silicone glass cloth board

3250 silicone epoxy laminated glass cloth is a silane-treated alkali-free glass cloth dipped in silicone epoxy resin, baked, dried, hot-pressed and processed into a heat-resistant grade H cloth.

3.10.1.3 9331 modified polyphenylene ether glass cloth plate

It is made by using a special alkali-free glass cloth for electricians dipped in modified dimethyl ether resin, baked and hot pressed.The board has good mechanical properties and electrical properties after immersion, and the heat resistance level is H-level. At present, 9331 modified diphenylether glass cloth board is widely used for H-level dry transformers as air gap struts, air gap pads, iron blocks and phase partitions.

3.10.1.4 9334 Bismaleimide laminated glass cloth (referred to as bismaleimide glass cloth) is made of glass cloth dipped in bismaleimide resin, baked and hot pressed.It has high mechanical properties and dielectric properties, good moisture resistance and processability, and a heat resistance grade of H

3.11 Nomex cardboard

Nomex cardboard is a kind of cardboard made from a synthetic material based on aromatic amide fiber.

3.12 Pull-out rod

The inter-stage rods, air gap struts, screws and screws of the core column of dry-type transformers often use glass wire drawing rods.

The pull-out rod is an alkali-free cluster glass treated with silane. After the resin is leached, it passes through the guide roller, enters the outer mold preheater, and then enters the curing furnace for thermosetting molding, and then is continuously pulled out by the pull-out device.

The heat resistance level of the pull-out rod is determined by the heat resistance level of the resin used.It can produce various heat-resistant grade products of B, F, and H grades.

If a magnetic material is added to the resin, a magnetic pull-out piece can be produced, and if a material such as carbon fiber is added, a semiconductor pull-out piece can be produced.

3.13 Electrician thin mold and electrician composite material

It has excellent dielectric properties and belongs to thin sheet insulating materials.

Electrical films include polypropylene film, polyester film and polyimide film.A composite material is a composite product made of one or both sides of a film glued to a fibrous material.

3.13.1 6020 polyester film

3.13.2 6050 polyimide film

3.13.3 Polyester thin polyester fiber non-woven soft composite material (DMD)

It is a three-layer soft composite material made of polyester fiber non-woven fabric (D) pasted on both sides of a layer of polyester film (M).DMD has excellent electrical insulation, heat resistance and mechanical strength, as well as excellent impregnation properties.It is generally used as a class B dry transformer layer insulation.The material composition is a polyester non-woven fabric with 0.05mm pasted on both sides of the polyester film.The polyester film and the non-woven fabric are bonded by a polyurethane adhesive.

3.13.4 Polyester film aromatic amine fiber paper soft composite material (NMN)

A three-layer (NMN) soft composite material made of polyester film (M) pasted with polyarylamide fiber paper (Nomex) on both sides.With excellent heat resistance, dielectric properties and high mechanical strength, it is suitable for F-grade electrical insulation.

3.13.5 Polyimide film polyarylamide fiber paper soft composite material (NHN)

It is made of polyarylamide fiber paper (Nomex) bonded with an H-grade adhesive on both sides of the polyimide film. It is currently the most advanced thin-layer insulating material. It has excellent heat resistance, good dielectric properties, small water absorption and excellent moisture resistance. It belongs to the H-grade insulating material.It can be used for four-layer insulation of H-class dry transformers.

3.14 Glass lacquer cloth

The glass lacquer cloth is made of alkali-free glass cloth used by electricians dipped in insulating paint and baked."Dry transformer.

3.14.1 Oily lacquered silk

It is made of refined high-quality mulberry silk evenly soaked in oily insulating varnish and dried and processed. The material has certain dielectric and mechanical properties.Oily lacquered silk has a heat-resistant grade of Class A and can be used for oil-immersed transformers and transformer lead dressing.

3.15 Insulating material for transformer lashing

The insulating materials used for transformer lashing are cotton tape, tightening tape, semi-dry thin wire tape, mesh semi-dry weft-free tape, glass cloth tape and polyester rope.

3.15.1 Glass fiber

According to the content of metal oxides (Na20, K20), glass fibers can be divided into alkali yarns (greater than 1%), medium alkali yarns (about 1%) and alkali-free yarns (less than 0.8%).According to the surface lubricant during drawing, it is divided into two lubricants: paraffin wax and silane.

3.15.2 Plain grain alkali-free glass fiber tape

Woven from alkali-free glass fiber with a thickness of 0.06, 0.08, 0.17mm

3.15.3 Impregnated plain weave lashing belt

3.15.4 Epoxy semi-dry thin weft belt

3.15.5 Resin-impregnated glass fiber weft-free lashing belt

The resin-impregnated glass fiber weft-free lashing belt for electricians (hereinafter referred to as the weft-free belt) is used as a fastening and lashing material for motor armatures and transformer cores.In my country, the production of this product began in 1970.Due to the low technical level at that time, the surface of the weft-free belt produced was mesh-like, easy to lose silk, and the utilization rate was about 70%.In recent years, Italian and American technology have been introduced to produce mesh weft-free belts.It fully meets the requirements of mechanical lashing of the iron core, and it has high tensile strength and certain elasticity and softness.The adhesion between the layers is good, and the iron core can be firmly tied without sticking to the roller.The resin used for lashing can be used in 105-degree transformer oil for a long time, and it has good compatibility with transformer oil.The thickness of the weft-free belt is 0.17, 0.20, 0.25, and 0.30 in four specifications.