CA1212436A - Compound insulator - Google Patents
Compound insulatorInfo
- Publication number
- CA1212436A CA1212436A CA000414888A CA414888A CA1212436A CA 1212436 A CA1212436 A CA 1212436A CA 000414888 A CA000414888 A CA 000414888A CA 414888 A CA414888 A CA 414888A CA 1212436 A CA1212436 A CA 1212436A
- Authority
- CA
- Canada
- Prior art keywords
- glass
- composite insulator
- rod
- insulator according
- glass fibres
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B17/00—Insulators or insulating bodies characterised by their form
- H01B17/32—Single insulators consisting of two or more dissimilar insulating bodies
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
- H01B3/08—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances quartz; glass; glass wool; slag wool; vitreous enamels
- H01B3/087—Chemical composition of glass
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Insulators (AREA)
- Insulating Bodies (AREA)
- Organic Insulating Materials (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The invention relates to a composite insulator of plastic of the type used for high voltage exposed power lines, consisting of a glass fibre reinforced plastic rod, plastic sheds surrounding the rod, and fittings installed on the rod ends. The glass fibres are arranged in the plastic rod with their axes parallel to the longitudinal axis of the rod and consist of a glass which has either a low or no boron content.
The invention relates to a composite insulator of plastic of the type used for high voltage exposed power lines, consisting of a glass fibre reinforced plastic rod, plastic sheds surrounding the rod, and fittings installed on the rod ends. The glass fibres are arranged in the plastic rod with their axes parallel to the longitudinal axis of the rod and consist of a glass which has either a low or no boron content.
Description
I
Tins invention relates to composite plastic insulators particularly for high voltage power lines, and having a glass fire reinforced plastic rod, plastic sheds arranged on the rod, and fittings on the ends of the God.
Composite insulators of this general type are known, for example, from Nazi 2650363 and satisfy specific electrical requiremeues. The rod must be electrically resistant to puncture discharge. In addition, the sheds must be secured to the rod (also called a trunk) so that no discharge penetration can take puce in the junction area with the rod. m e sheds themselves must be sufficiently thick that they too do jot puncture. Finally, the sheds must be weather-, ultraviolet-, and ozone-rssistant and display great resistance to flyer.
Besides the electrical strength, the glass fire reinforced plastic rod must show considerable mechanical strength. Such mechanical strength depends on the composition of the material, the type and positioning of the fires, and the bond between the fires and the plastic.
It is known chat the electrical and mechanical strength of the glass reinforced rod of a composite insulator can fall considerably after an extended period of use, particularly in exposed high voltage power lines as a result of environmental influences or weathering. Attempts have been made to shroud the rods with the sheds in a manner such that atmospheric effects do penetrate to the rod itself. However, to date this has not been achieved satisfactorily and the possibility of insulator breakdown is always present.
Another proposal (DEMOS 2650363) treats the problem of water attack on the glass fire reinforced plastic rod as being primarily responsible for the strength reduction. Glass fires asp thus employed which, although of conventional composition, are of particularly low alkali content. Such fires by their very nature ensure a low level of water volubility and if alkali is leached from glass fires it can initiate and accelerate hydrolysis ox the bonding resin. In addition to the use of low alkali content glass fires a non-saponifiable bonding resin resistant to water attack is also employed.
Despite the measures described above, breakdown still occurs, particularly in exposed power line insulators of this type. Initially such failures appeared inexplicable and occurred even after a relatively short period of use under relatively slight mechanical load. The fractures displayed by the insulators which failed in use, differed visually and quite distinctly from those which occurred, for example, during fracture tests conducted in laboratories and also in long term strength tests measured in years in exposed test areas. A plastic rod reinforced with continuous glass fires laid parallel to the axis breaks under mechanical load by separation of the bonding resin from the glass fires which then tear. The rod thus splinters longitudinally. Fractures which occur on site however are oriented almost perpendicularly to the longitudinal axis of the rod and the fracture surfaces are smooth.
Surprisingly, tests reveal that the smooth fractures perpendicular to the longitudinal axis of the rod result from the effects of aqueous nitric acid. It has been known for a considerable time that nitric acid is formed from atmospheric nitrogen by electrical discharge in the presence of air and water. Clearly, this occurs during electric discharge activity on the surface of the insulator sheds in the presence of dirt and moisture. It appears that such nitric acid diffuses through the surface of the sheds or is conveyed through gaps and cracks between individual sheds and reaches the glass fire reinforced plastic rod to cause the smooth transverse fracture. This would explain the absence of occurrence of transverse fractures in laboratory tests and why such fractures are not described in the literature covering glass fire reinforced plastics.
It is an object of the present invention to prevent transverse fractures which occur on site in effffl~ffn~* insulators of the type described above.
Here described is a my insulator ox i)]flStiC, consisting ox a glass fire reinforced plastic rod, of plastic sheds arranged on the rod, an-l fittings on the rod ends, in which glass ~ibres arrange axially parallel in the plastic rod consist of aluminum-silicate glass tilclt has a low boron content or else preferably, is free of boron. In the corltext of this disclosure, glass having a low boron content is understood to be a glass that contains boron or a boron compound, calculated as B20~ at one percent by weight maximum.
Ryan free glasses are lasses which contain boron or boron compounds, calculated as B203, at less than 0.01 percentage parts by weight lower boron contents can be measured only by trace analysis and are negligible for purposes of this disclosure.
Particularly suitable are glass fires of glass having the following composition yin percentage parts by weight):
Sue 55-80 Aye 20-30 Moo 5-15 Coo 0-10 Noah 0-1 Preferred are glass fires of a glass having the following composition.
Sue 60-80 Aye 20-30 Moo 5-15 Coo 0-2 Noah Glass fires having no Coo are particularly resistant and are thus preferred.
I
The glass Flares should have a thickness of 5 to I Jim laid up in continuous lengths parallel to the axis of the rod.
Additionally in the glass fires here described, it is advantageous that the alkali oxide content of the glass be less than I part by weight.
Preferably the glass fires should be free of alkali. Water attack can thus be prevented and the resistance to electrical puncture, can be increased.
To increase the resistance of the rod to electrical breakdown tune bonding resin surrounding the glass fires can be a resin resistant to attack by water. It is preferred that the bonding resin have no molecules which can be hydrolyzed. An epoxy resin of the glycidyl ether type is suitable.
So that the insulator is economical to produce, prefabricated components for the sheds may be used. Insulators of any desired length can be produced. The glass fire reinforced plastic rod can be made for example, in a continuous drawing process. The surface of the rod, and of the sheds, can be treated in a known manner with adhesive agents and joined, for example, by integral casting, vulcanizing, cementing, or the like.
The radial joints between the sheds no longer play a dominant role, since the glass fire reinforced plastic rod is resistant to nitric acid as well as to water.
In considering the transverse fracture problem, two conceivable solutions to the problem outlined above emerged. Firstly, attempts could be made to ensure that no aqueous nitric acid reached the plastic rod. This possibility now appears, for all practical purposes, to be impracticable, since the nitric acid diffuses through plastic and over the long term it was impossible to ensure that gaps or breaks did not occur in the sheds, between them or between the sheds and the rod end fittings. Secondly, a solution could be to use materials for the insulator rod resistant to nitric acid.
Tests in which rod material of commercially available compound insulators was stored in nitric acid, revealed that neither the glass fires nor the plastic used as the rod material were attacked by aqueous nitric acid, and thus one was led to conclude that selection of the rod material alone would not lead to a solution. It is most surprising therefore that, replacement of the normally used glass flare types by boron free glass fires essentially eliminated the danger of transverse fracture. The precise reasons for this phenomenon have not yet been determined.
Aqueous nitric acid attack on glass containing boron can be accepted as a cause for the transverse fractures found in insulators. Thus if glass lo with a boron content is simultaneously subjected to tension and nitric acid it is possible that minuscule cracks will occur in the surface ox the individual glass fires, and that these cracks will propagate as helixes around the fire. These minuscule cracks are responsible, at least in laboratory tests, for transverse fracture of the rod. Clearly, what is involved is not chemical attack, in the sense of swelling or dissolution) but more a type of tension crack corrosion that does not occur in boron-free fires or which occurs only at higher degrees of elongation or higher acid concentrations.
It is, however, known that, glass fiber having a low alkali content and free of boron or boron compounds render mechanically loaded insulated components sufficiently strong for high voltage switching equipment which contains sulfuric hexafluoride gas (European Patent 0 02~ 281, published I May 1983)~ Knowledge of is effect on the fires of a so called R-type glass does rut immediately lead the man skilled in the art to the solution of the problems herein, since the decomposition products of SF6 do not occur in the areas of use of exposed power line compound insulators.
The selection of glass fires having a low or no boron content did not suggest itself since f1bres of glass containing boron, the so-called E glasses, are usually used for such electrical components on account ox their ! I I
extremely good electrical resistance. E type glass is not attacked by aqueous nitric acid, so that its exchange for other glass fires could not reasonably be considered as warranted. This obstacle must be overcome in order to solve the problem outlined herein and to which the present invention provides a solution.
ore particularly in accordance with the invention there is provided s composite insulator for outdoor high volts lines, comprising:
a lass fiber reinforced plastic rod having ~etsl fittings at the end thereof, the glass fibers brine disposed parallel to the axis of the rod, and consisting essentially of a Cougher glass hazing little or no boron content, and consisting essentially of from about 55 to about 80 White Sue, from stout 20 to about 30 wit% Aye, from about 5 to about 15 wit% Moo and from Nero to about 1 wit% Noah, whereby the composite insulator it resistant to in situ occurring transverse fractures The boron content based on B203 is at most one percent part by weight and when free of boron contain less than 0.01 % parts by weight of B203. The gloss fires preferably have an alkaline oxide content of less than one percent part by weight, but more preferably are alkaline free 80nding resin surrounding the glass fires is preferably resistant to attack by water contains no hydrolyzable molecules and may be an epoxy resin of the glyc;dyl ether type. The lass fires may be continuous and a thickness of 5 to 40 us Specific embodiments of the invention will now be described with reference to the accompanying drawings in which;
Fig. 1 is a schematic representation of a test set up used to examine resistance to transverse fracture;
Fig. 2 is a graph of the test results, Fix. 3 is an insulator in partial section, embodying the invention.
The test piece shown in Fig. 1 consists of a g1BSS fire reinforced plastic rod 1 with end fittings 2, to which a tensile force Z can be applied.
AL ICY
Carried on the rod is an acid reservoir I, or example, a modified polyethylene bottle Inounted on the rod and sealed with insulating tape.
Fig. 2 shows graphs of the relationship between Lye tensile force Z
and the fracture time for test pieces of Fig. 1 plotted as Log Z against Log T. Curve 4 indicates the tensile force/time until fracture of the rod of a glass fire reinforced plastic rod not exposed to the effects of acid.
Curve 5 shows the tensile force/time to fracture relationship with the acid reservoir 3 filled with a lo HN03 solution (approximately 6.5% nitric acid by weight of a glass ire reinforced plastic rod, with fires of boron content, calculated as B203 between 2 and 6% by weight. The fracture/time behavior of a rod, with glass fires containing no boron is indicated by curve 6. The differences in fracture time between known glass fire reinforced plastic rods (glass containing boron) and the new rods, with boron free glass, is clearly demonstrated.
The use of boron glass in electrical technology, and particularly glass fire reinforced plastic rods in compound insulators, is conventional (see DEMOS 27 46 870, page 10). The so-called "E type glasses" are used in electrical technology (the "E" standing for "electrical"). All commercially available glass fires obtainable with the E-type glass designation contain various quantities of boron. Curve 5 in Fig. 2 for typical commercial glass fires can display certain deviations from that illustrated and this can be traced back to the varying boron content of E-type glasses. In comparison to the behavior of the new rods here described (Fig. 2, line 6) this variation among such E-type glasses is neglible.
Fig. 3 shows a compound insulator embodying the invention, which consists of a glass fire reinforced plastic rod 7 made of epoxy resin of the glycidyl ether type, and continuous parallel glass fires of boron content, calculated as B203, of less than 0.01~, and of an alkali content, calculated as Noah, less than lo (all parts by weight).
The insulator also consists of a shed string made of individual prefabricated sheds 8, installed on the rod and securely bonded to it if. both the mechanical and electrical sense. In addition, there are metallic connector fittings 9, secured to the ends of thecompositeinsulator. The connection between the rod 7 and the fittings 9 can be made using known technology such as by pressing or keying.
Hoover, dependent on the type of material used for the sheds, it may be advantageous to prefabricate the string and install it in a separate lo production stage. Other materials used for the shed string can comprise casting, pressing 9 extruding or injection molding of the shed bodies in a single or multiparty mold as the most economical solution.
Silicone elastomers can be used for the shed coverings Sue sxhhaMe Ann proven to be good insulator materials. Silicone elastomers of various consistencies containing fillers determined by the area of Sue, such as quartz flower or aluminum oxide hydrate, and Rich kitten pigments and polymerizing agents can be easily processed. For specific areas of application, elastomers based on ethylene-propylene can be suitable as materials for the shed elements. Other materials such as cycloaliphatic epoxy resins or polytetrafluoroethylene can also be used for insulators embodying the invention.
Tins invention relates to composite plastic insulators particularly for high voltage power lines, and having a glass fire reinforced plastic rod, plastic sheds arranged on the rod, and fittings on the ends of the God.
Composite insulators of this general type are known, for example, from Nazi 2650363 and satisfy specific electrical requiremeues. The rod must be electrically resistant to puncture discharge. In addition, the sheds must be secured to the rod (also called a trunk) so that no discharge penetration can take puce in the junction area with the rod. m e sheds themselves must be sufficiently thick that they too do jot puncture. Finally, the sheds must be weather-, ultraviolet-, and ozone-rssistant and display great resistance to flyer.
Besides the electrical strength, the glass fire reinforced plastic rod must show considerable mechanical strength. Such mechanical strength depends on the composition of the material, the type and positioning of the fires, and the bond between the fires and the plastic.
It is known chat the electrical and mechanical strength of the glass reinforced rod of a composite insulator can fall considerably after an extended period of use, particularly in exposed high voltage power lines as a result of environmental influences or weathering. Attempts have been made to shroud the rods with the sheds in a manner such that atmospheric effects do penetrate to the rod itself. However, to date this has not been achieved satisfactorily and the possibility of insulator breakdown is always present.
Another proposal (DEMOS 2650363) treats the problem of water attack on the glass fire reinforced plastic rod as being primarily responsible for the strength reduction. Glass fires asp thus employed which, although of conventional composition, are of particularly low alkali content. Such fires by their very nature ensure a low level of water volubility and if alkali is leached from glass fires it can initiate and accelerate hydrolysis ox the bonding resin. In addition to the use of low alkali content glass fires a non-saponifiable bonding resin resistant to water attack is also employed.
Despite the measures described above, breakdown still occurs, particularly in exposed power line insulators of this type. Initially such failures appeared inexplicable and occurred even after a relatively short period of use under relatively slight mechanical load. The fractures displayed by the insulators which failed in use, differed visually and quite distinctly from those which occurred, for example, during fracture tests conducted in laboratories and also in long term strength tests measured in years in exposed test areas. A plastic rod reinforced with continuous glass fires laid parallel to the axis breaks under mechanical load by separation of the bonding resin from the glass fires which then tear. The rod thus splinters longitudinally. Fractures which occur on site however are oriented almost perpendicularly to the longitudinal axis of the rod and the fracture surfaces are smooth.
Surprisingly, tests reveal that the smooth fractures perpendicular to the longitudinal axis of the rod result from the effects of aqueous nitric acid. It has been known for a considerable time that nitric acid is formed from atmospheric nitrogen by electrical discharge in the presence of air and water. Clearly, this occurs during electric discharge activity on the surface of the insulator sheds in the presence of dirt and moisture. It appears that such nitric acid diffuses through the surface of the sheds or is conveyed through gaps and cracks between individual sheds and reaches the glass fire reinforced plastic rod to cause the smooth transverse fracture. This would explain the absence of occurrence of transverse fractures in laboratory tests and why such fractures are not described in the literature covering glass fire reinforced plastics.
It is an object of the present invention to prevent transverse fractures which occur on site in effffl~ffn~* insulators of the type described above.
Here described is a my insulator ox i)]flStiC, consisting ox a glass fire reinforced plastic rod, of plastic sheds arranged on the rod, an-l fittings on the rod ends, in which glass ~ibres arrange axially parallel in the plastic rod consist of aluminum-silicate glass tilclt has a low boron content or else preferably, is free of boron. In the corltext of this disclosure, glass having a low boron content is understood to be a glass that contains boron or a boron compound, calculated as B20~ at one percent by weight maximum.
Ryan free glasses are lasses which contain boron or boron compounds, calculated as B203, at less than 0.01 percentage parts by weight lower boron contents can be measured only by trace analysis and are negligible for purposes of this disclosure.
Particularly suitable are glass fires of glass having the following composition yin percentage parts by weight):
Sue 55-80 Aye 20-30 Moo 5-15 Coo 0-10 Noah 0-1 Preferred are glass fires of a glass having the following composition.
Sue 60-80 Aye 20-30 Moo 5-15 Coo 0-2 Noah Glass fires having no Coo are particularly resistant and are thus preferred.
I
The glass Flares should have a thickness of 5 to I Jim laid up in continuous lengths parallel to the axis of the rod.
Additionally in the glass fires here described, it is advantageous that the alkali oxide content of the glass be less than I part by weight.
Preferably the glass fires should be free of alkali. Water attack can thus be prevented and the resistance to electrical puncture, can be increased.
To increase the resistance of the rod to electrical breakdown tune bonding resin surrounding the glass fires can be a resin resistant to attack by water. It is preferred that the bonding resin have no molecules which can be hydrolyzed. An epoxy resin of the glycidyl ether type is suitable.
So that the insulator is economical to produce, prefabricated components for the sheds may be used. Insulators of any desired length can be produced. The glass fire reinforced plastic rod can be made for example, in a continuous drawing process. The surface of the rod, and of the sheds, can be treated in a known manner with adhesive agents and joined, for example, by integral casting, vulcanizing, cementing, or the like.
The radial joints between the sheds no longer play a dominant role, since the glass fire reinforced plastic rod is resistant to nitric acid as well as to water.
In considering the transverse fracture problem, two conceivable solutions to the problem outlined above emerged. Firstly, attempts could be made to ensure that no aqueous nitric acid reached the plastic rod. This possibility now appears, for all practical purposes, to be impracticable, since the nitric acid diffuses through plastic and over the long term it was impossible to ensure that gaps or breaks did not occur in the sheds, between them or between the sheds and the rod end fittings. Secondly, a solution could be to use materials for the insulator rod resistant to nitric acid.
Tests in which rod material of commercially available compound insulators was stored in nitric acid, revealed that neither the glass fires nor the plastic used as the rod material were attacked by aqueous nitric acid, and thus one was led to conclude that selection of the rod material alone would not lead to a solution. It is most surprising therefore that, replacement of the normally used glass flare types by boron free glass fires essentially eliminated the danger of transverse fracture. The precise reasons for this phenomenon have not yet been determined.
Aqueous nitric acid attack on glass containing boron can be accepted as a cause for the transverse fractures found in insulators. Thus if glass lo with a boron content is simultaneously subjected to tension and nitric acid it is possible that minuscule cracks will occur in the surface ox the individual glass fires, and that these cracks will propagate as helixes around the fire. These minuscule cracks are responsible, at least in laboratory tests, for transverse fracture of the rod. Clearly, what is involved is not chemical attack, in the sense of swelling or dissolution) but more a type of tension crack corrosion that does not occur in boron-free fires or which occurs only at higher degrees of elongation or higher acid concentrations.
It is, however, known that, glass fiber having a low alkali content and free of boron or boron compounds render mechanically loaded insulated components sufficiently strong for high voltage switching equipment which contains sulfuric hexafluoride gas (European Patent 0 02~ 281, published I May 1983)~ Knowledge of is effect on the fires of a so called R-type glass does rut immediately lead the man skilled in the art to the solution of the problems herein, since the decomposition products of SF6 do not occur in the areas of use of exposed power line compound insulators.
The selection of glass fires having a low or no boron content did not suggest itself since f1bres of glass containing boron, the so-called E glasses, are usually used for such electrical components on account ox their ! I I
extremely good electrical resistance. E type glass is not attacked by aqueous nitric acid, so that its exchange for other glass fires could not reasonably be considered as warranted. This obstacle must be overcome in order to solve the problem outlined herein and to which the present invention provides a solution.
ore particularly in accordance with the invention there is provided s composite insulator for outdoor high volts lines, comprising:
a lass fiber reinforced plastic rod having ~etsl fittings at the end thereof, the glass fibers brine disposed parallel to the axis of the rod, and consisting essentially of a Cougher glass hazing little or no boron content, and consisting essentially of from about 55 to about 80 White Sue, from stout 20 to about 30 wit% Aye, from about 5 to about 15 wit% Moo and from Nero to about 1 wit% Noah, whereby the composite insulator it resistant to in situ occurring transverse fractures The boron content based on B203 is at most one percent part by weight and when free of boron contain less than 0.01 % parts by weight of B203. The gloss fires preferably have an alkaline oxide content of less than one percent part by weight, but more preferably are alkaline free 80nding resin surrounding the glass fires is preferably resistant to attack by water contains no hydrolyzable molecules and may be an epoxy resin of the glyc;dyl ether type. The lass fires may be continuous and a thickness of 5 to 40 us Specific embodiments of the invention will now be described with reference to the accompanying drawings in which;
Fig. 1 is a schematic representation of a test set up used to examine resistance to transverse fracture;
Fig. 2 is a graph of the test results, Fix. 3 is an insulator in partial section, embodying the invention.
The test piece shown in Fig. 1 consists of a g1BSS fire reinforced plastic rod 1 with end fittings 2, to which a tensile force Z can be applied.
AL ICY
Carried on the rod is an acid reservoir I, or example, a modified polyethylene bottle Inounted on the rod and sealed with insulating tape.
Fig. 2 shows graphs of the relationship between Lye tensile force Z
and the fracture time for test pieces of Fig. 1 plotted as Log Z against Log T. Curve 4 indicates the tensile force/time until fracture of the rod of a glass fire reinforced plastic rod not exposed to the effects of acid.
Curve 5 shows the tensile force/time to fracture relationship with the acid reservoir 3 filled with a lo HN03 solution (approximately 6.5% nitric acid by weight of a glass ire reinforced plastic rod, with fires of boron content, calculated as B203 between 2 and 6% by weight. The fracture/time behavior of a rod, with glass fires containing no boron is indicated by curve 6. The differences in fracture time between known glass fire reinforced plastic rods (glass containing boron) and the new rods, with boron free glass, is clearly demonstrated.
The use of boron glass in electrical technology, and particularly glass fire reinforced plastic rods in compound insulators, is conventional (see DEMOS 27 46 870, page 10). The so-called "E type glasses" are used in electrical technology (the "E" standing for "electrical"). All commercially available glass fires obtainable with the E-type glass designation contain various quantities of boron. Curve 5 in Fig. 2 for typical commercial glass fires can display certain deviations from that illustrated and this can be traced back to the varying boron content of E-type glasses. In comparison to the behavior of the new rods here described (Fig. 2, line 6) this variation among such E-type glasses is neglible.
Fig. 3 shows a compound insulator embodying the invention, which consists of a glass fire reinforced plastic rod 7 made of epoxy resin of the glycidyl ether type, and continuous parallel glass fires of boron content, calculated as B203, of less than 0.01~, and of an alkali content, calculated as Noah, less than lo (all parts by weight).
The insulator also consists of a shed string made of individual prefabricated sheds 8, installed on the rod and securely bonded to it if. both the mechanical and electrical sense. In addition, there are metallic connector fittings 9, secured to the ends of thecompositeinsulator. The connection between the rod 7 and the fittings 9 can be made using known technology such as by pressing or keying.
Hoover, dependent on the type of material used for the sheds, it may be advantageous to prefabricate the string and install it in a separate lo production stage. Other materials used for the shed string can comprise casting, pressing 9 extruding or injection molding of the shed bodies in a single or multiparty mold as the most economical solution.
Silicone elastomers can be used for the shed coverings Sue sxhhaMe Ann proven to be good insulator materials. Silicone elastomers of various consistencies containing fillers determined by the area of Sue, such as quartz flower or aluminum oxide hydrate, and Rich kitten pigments and polymerizing agents can be easily processed. For specific areas of application, elastomers based on ethylene-propylene can be suitable as materials for the shed elements. Other materials such as cycloaliphatic epoxy resins or polytetrafluoroethylene can also be used for insulators embodying the invention.
Claims (10)
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A composite insulator for outdoor high voltage lines, comprising:
a glass fiber reinforced plastic rod having metal fittings at the ends thereof, the glass fibers being disposed parallel to the axis of the rod, and consisting essentially of a CaO-free glass having little or no boron content, and consisting essentially of from about 55 to about 80 wt% SiO2, from about 20 to about 30 wt% A1203, from about 5 to about 15 wt% MgO and from zero to about 1 wt% Na20, whereby the composite insulator is resistant to in situ occurring transverse fractures.
a glass fiber reinforced plastic rod having metal fittings at the ends thereof, the glass fibers being disposed parallel to the axis of the rod, and consisting essentially of a CaO-free glass having little or no boron content, and consisting essentially of from about 55 to about 80 wt% SiO2, from about 20 to about 30 wt% A1203, from about 5 to about 15 wt% MgO and from zero to about 1 wt% Na20, whereby the composite insulator is resistant to in situ occurring transverse fractures.
2. A composite insulator according to claim 1, the boron content of the glass fibres, calculated as B203 being at most 1% part by weight.
3. A composite insulator according to claim 2, the boron content of the glass fibres being less than 0.01% parts by weight.
4. A composite insulator according to claim 1, wherein the glass fibers are comprised of a glass consisting essentially of from about 60 to about 80 wt% SiO2, from about 20 to about 30 wt% A1203, from about 5 to about 15 wt% MgO, and are substantially free of Na20
5. A composite insulator according to claim 1,2 or 4, the glass fibres being continuous and of a thickness of 5 to 40 um.
6. A composite insulator according to claim 1, 2 or 3, the glass fibres having an alkaline oxide content of less than 1% part by weight.
7. A composite insulator according to claim 1, 2 or 3, the glass fibres being alkali free.
8. A composite insulator according to claim 1, 2 or 4, bonding resin surrounding the glass fibres being a resin resistant to attack by water.
9. A composite insulator according, to claim 1, 2 or 4, bonding resin surrounding the glass fibres being a resin containing no hydrolisable molecules.
10. A composite insulator according to claim 1, 2 or 4, bonding resin surrounding the glass fibres being an epoxy resin of the glycidyl ether type.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP81/00175 | 1981-11-04 | ||
| PCT/EP1981/000175 WO1983001707A1 (en) | 1981-11-04 | 1981-11-04 | Connection insulator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1212436A true CA1212436A (en) | 1986-10-07 |
Family
ID=8164829
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000414888A Expired CA1212436A (en) | 1981-11-04 | 1982-11-04 | Compound insulator |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0092548B1 (en) |
| JP (1) | JPS58501528A (en) |
| AU (1) | AU7892482A (en) |
| CA (1) | CA1212436A (en) |
| DE (1) | DE3172780D1 (en) |
| WO (1) | WO1983001707A1 (en) |
| ZA (1) | ZA828103B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5986216A (en) * | 1997-12-05 | 1999-11-16 | Hubbell Incorporated | Reinforced insulator |
| CN100452248C (en) * | 2006-02-28 | 2009-01-14 | 陕西泰普瑞电工绝缘技术有限公司 | Non-mold release agent composite insulator core rod |
| AT507991B1 (en) * | 2009-03-06 | 2012-01-15 | Kuvag Kunststoffverarbeitungs Ges M B H | CREDITS ISOLATOR |
| CN104992800B (en) * | 2015-06-18 | 2016-11-02 | 西安高强绝缘电气有限责任公司 | A kind of manufacture method of the combined core rod of insulator of multicore |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2650363C2 (en) * | 1976-11-03 | 1985-10-10 | Rosenthal Technik Ag, 8672 Selb | Composite insulator for high voltage open air applications |
| CH640973A5 (en) * | 1978-06-02 | 1984-01-31 | Micafil Ag | Method for producing an insulating rod, which is resistant to tension, compression and torsion and has attachment fittings, and a device for carrying out the method |
| CH640664A5 (en) * | 1979-11-05 | 1984-01-13 | Sprecher & Schuh Ag | MECHANICAL STRENGTHENED GLASS FIBER REINFORCED PLASTIC INSULATING PART. |
-
1981
- 1981-11-04 JP JP50366581A patent/JPS58501528A/en active Granted
- 1981-11-04 AU AU7892482A patent/AU7892482A/en active Pending
- 1981-11-04 EP EP81903257A patent/EP0092548B1/en not_active Expired
- 1981-11-04 WO PCT/EP1981/000175 patent/WO1983001707A1/en active IP Right Grant
- 1981-11-04 DE DE8181903257T patent/DE3172780D1/en not_active Expired
-
1982
- 1982-11-04 CA CA000414888A patent/CA1212436A/en not_active Expired
- 1982-11-04 ZA ZA828103A patent/ZA828103B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE3172780D1 (en) | 1985-12-05 |
| ZA828103B (en) | 1984-02-29 |
| AU7892482A (en) | 1983-05-18 |
| EP0092548A1 (en) | 1983-11-02 |
| WO1983001707A1 (en) | 1983-05-11 |
| JPH0145684B2 (en) | 1989-10-04 |
| EP0092548B1 (en) | 1985-10-30 |
| JPS58501528A (en) | 1983-09-08 |
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