CA1199768A - Foil manufacture - Google Patents
Foil manufactureInfo
- Publication number
- CA1199768A CA1199768A CA000433321A CA433321A CA1199768A CA 1199768 A CA1199768 A CA 1199768A CA 000433321 A CA000433321 A CA 000433321A CA 433321 A CA433321 A CA 433321A CA 1199768 A CA1199768 A CA 1199768A
- Authority
- CA
- Canada
- Prior art keywords
- resin
- strand
- mica powder
- paste
- layer
- 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
- 239000011888 foil Substances 0.000 title claims abstract description 25
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 6
- 239000010445 mica Substances 0.000 claims abstract description 31
- 229910052618 mica group Inorganic materials 0.000 claims abstract description 31
- 238000000034 method Methods 0.000 claims abstract description 20
- 239000000843 powder Substances 0.000 claims abstract description 20
- 239000000463 material Substances 0.000 claims abstract description 17
- 230000008569 process Effects 0.000 claims abstract description 16
- 235000011837 pasties Nutrition 0.000 claims abstract description 11
- 239000000057 synthetic resin Substances 0.000 claims abstract description 9
- 229920003002 synthetic resin Polymers 0.000 claims abstract description 8
- 239000000945 filler Substances 0.000 claims abstract description 6
- 230000002787 reinforcement Effects 0.000 claims abstract description 6
- 229920005989 resin Polymers 0.000 claims description 15
- 239000011347 resin Substances 0.000 claims description 15
- 239000004744 fabric Substances 0.000 claims description 11
- 239000003822 epoxy resin Substances 0.000 claims description 9
- 229920000647 polyepoxide Polymers 0.000 claims description 9
- 238000003490 calendering Methods 0.000 claims description 5
- 239000000835 fiber Substances 0.000 claims description 4
- YGANSGVIUGARFR-UHFFFAOYSA-N dipotassium dioxosilane oxo(oxoalumanyloxy)alumane oxygen(2-) Chemical compound [O--].[K+].[K+].O=[Si]=O.O=[Al]O[Al]=O YGANSGVIUGARFR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052627 muscovite Inorganic materials 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 2
- 229910052628 phlogopite Inorganic materials 0.000 claims description 2
- 229920001225 polyester resin Polymers 0.000 claims description 2
- 239000004645 polyester resin Substances 0.000 claims description 2
- 239000012779 reinforcing material Substances 0.000 claims description 2
- 229920002050 silicone resin Polymers 0.000 claims description 2
- 239000002904 solvent Substances 0.000 claims description 2
- 239000000203 mixture Substances 0.000 description 11
- 239000004848 polyfunctional curative Substances 0.000 description 8
- 239000011810 insulating material Substances 0.000 description 6
- 239000011152 fibreglass Substances 0.000 description 5
- 238000003860 storage Methods 0.000 description 5
- 229920001187 thermosetting polymer Polymers 0.000 description 4
- 239000004593 Epoxy Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 150000001412 amines Chemical class 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- -1 diphenyl glycidyl Chemical group 0.000 description 2
- 239000003365 glass fiber Substances 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- HPILSDOMLLYBQF-UHFFFAOYSA-N 2-[1-(oxiran-2-ylmethoxy)butoxymethyl]oxirane Chemical compound C1OC1COC(CCC)OCC1CO1 HPILSDOMLLYBQF-UHFFFAOYSA-N 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 239000011353 cycloaliphatic epoxy resin Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000002648 laminated material Substances 0.000 description 1
- 239000004850 liquid epoxy resins (LERs) Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000012209 synthetic fiber Substances 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 230000032258 transport Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- 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
- H01B3/04—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances mica
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/001—Combinations of extrusion moulding with other shaping operations
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B19/00—Apparatus or processes specially adapted for manufacturing insulators or insulating bodies
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/001—Combinations of extrusion moulding with other shaping operations
- B29C48/0018—Combinations of extrusion moulding with other shaping operations combined with shaping by orienting, stretching or shrinking, e.g. film blowing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/001—Combinations of extrusion moulding with other shaping operations
- B29C48/0021—Combinations of extrusion moulding with other shaping operations combined with joining, lining or laminating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/04—Particle-shaped
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/07—Flat, e.g. panels
- B29C48/08—Flat, e.g. panels flexible, e.g. films
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/15—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor incorporating preformed parts or layers, e.g. extrusion moulding around inserts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/16—Articles comprising two or more components, e.g. co-extruded layers
- B29C48/18—Articles comprising two or more components, e.g. co-extruded layers the components being layers
- B29C48/21—Articles comprising two or more components, e.g. co-extruded layers the components being layers the layers being joined at their surfaces
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
- B29K2105/12—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of short lengths, e.g. chopped filaments, staple fibres or bristles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/34—Electrical apparatus, e.g. sparking plugs or parts thereof
- B29L2031/3412—Insulators
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Insulating Bodies (AREA)
- Glass Compositions (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Organic Insulating Materials (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
- Manufacturing Of Electric Cables (AREA)
- Laminated Bodies (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for the production of an electrical insulating foil com-prising substantially a thin-layer of electrical grade mica powder and a hardenable synthetic resin comprising forming a paste of electrical grade mica and a hardenable synthetic resin and optional fillers and/or reinforcement materials, forming a strand of said paste and subjecting the pasty strand to a calender or ribbon press to reduce the strand thickness into a thin-layer.
A process for the production of an electrical insulating foil com-prising substantially a thin-layer of electrical grade mica powder and a hardenable synthetic resin comprising forming a paste of electrical grade mica and a hardenable synthetic resin and optional fillers and/or reinforcement materials, forming a strand of said paste and subjecting the pasty strand to a calender or ribbon press to reduce the strand thickness into a thin-layer.
Description
76~3 STATE OF THE ART
The use of area insulatiny materials based on fine mica for the electrical insulation of coils and conductor rods of heavy-duty electrical machines is known and the said insulating materials are usually made of a support material such as glass fiber cloths or thermostable plastic foils bonded to a fine mica paper impregnated with a thermosetting resin which acts as a binder. The thermosetting resin in the said insula-ting material is in the B-state. The said area electrical insulating materials are applied to the element to be insula-ted such as a conductor rod as a tape or as a wide material and the coated element is heated in a coil press to cure the insulation and form the final product.
The preparation of the known area insulating materials is relatively expensive as the fine mica paper has to be prepared from mica in a suitable manner and then the support material and the fine mica paper are coated with the thermosetting resin and finally bonded together by calendering.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an inexpensive method of producing an electrically insulating foil made of a hard-enable synthetic resin and electrical grade mica and the foil pro-duced thereby.
It is another object of the invention to provide a novel method of electrically insulating elements and the elements pro-duced thereby.
These and other objects and advantages of the invention will become obvious from the following detai]ed description.
3~
7~
THE INVENTION
The invention provides a process for the production of an electrical insulating foil comprising substantially a thin-layer of electrical grade mica powder and a hardenable syn-thetic resin with a thickness of 0.1 to 0.5 mm comprising the steps oE
forming a pas-te of electrical grade mlca powder and a hardenable substantially solvent free synthetic resin and optional fillers and/or reinforcement material, forming a strand of said paste and evenly distributing the pasty strand over the entrance of a calender or a ribbon press to reduce the strand thickness into a thin-layer 0.1 to 0.5 mm thick. The foil preferably has a thick-ness of about 0.2 mm.
The expression "electrical grade mica" means mica mater-ia] free of all electrically conductive compounds or materials such as metals and the preferred mica is muscovite or phlogopite based powder with a grain range of 0.03 to 2.8 mm. The pasty strand preferably contains 35 to 70% by weight, more preferably 45 to 65% by weight, of the mica powder and up to 20% by weight of fillers and/or reinforcing materials.
The hardenable synthetic resin mixture may be based on an epoxy resin, a polyester resin or a silicone resin. Preferred are mixtures of epoxy resins with epoxy equivalents of 150 to 800.
The hardenable resins will contain a hardener such as an amine dissolved in a reactive thinner such as diphenyl glycidyl e-ther, butanediol diglycidyl ether or more preferably a low viscosity cycloaliphatic epoxy resin. The hardenable synthetic resin may be used in the liquid state.
In a preferred embodiment of the invention, a mixture of '~
~ a~7~
resin and mica and optional filler and/or reinforcement materials is added to an extruder and the hardener is separately added to the extruder whereby mixing of the pasty material takes place in the extruder itself.
In a preferred embodiment of the invention, the pasty strand is supplied to the calender nip or the nip of the ribbon press between two incoming webs of sheet type ma-terial and prefer-ably the thin layer produced in the calender or ribbon press is permanently bonded to at leas-t one of the sheet type webs or advantageously a fiber fabric web is placed between the pasty - 2a -'' '~' ~3 ~ ~ a~
7~b~
strand and one of the webs of sheet material before entry into the calender nip or nip of the ribbon press. The fiber fabric web is permanently bonded to the thin foil produced thereby.
While the production of the resin foils using an extruder followed by calendering is known, one skilled in the art would not expect the calender-ing of a strand of a mixture of mica powder and resin would produce a foil or thin layer in which the mica powder particles are oriented essentially parallel to the foil surfaces by the thickness reduction of the strand in the calender.
The particle orientation of the mica par~icles parallel to the layer surfaces is similar to tha-t of mica in known mica paper which is important to obtain high electrical strength values.
Referring now to the drawing:
The Figure is a schematic view of an apparatus for carrying out the process of the invention.
The apparatus of the Figure comprises a heatable double screw extruder 1 with only one of the two screws 2 being illustrated in the drawing. The extruder housing is connected to feed hopper 4 by feed inlet 3 into which mi.ca powder 6 is metered from supply tank 5 by metering spiral 7 and inlet feed 3 is also connected via line 8 and proportioning pump 9 to heatable storage vessel 10 for the hardenable resin. A second feed inlet 12 offset relative to inlet 3 in the direction of arrow 10 is connected via line 13 and proportion-ing pump 14 to storage vessel 15 holding hardener solution 31. The extruder 1 is provided with orifice 16 for extrusion of a round strand and can pivot in oscillation at the point of orifice 16 as indicated by 17 in a direction perpendicular to the drawing plane.
Following the extruder is a calendar with a pair of heatable calendar rolls 18 which enclose nip 19 and provided with a draw-off device for foil product 20 comprising two guide rollers 21 and 22, a pair of draw-off rollers 23 and a winding device 24. The ca.lender is also provided with unrolling devices 25, 26 and 27 to feed two separate foils 28 in tape form and glass fiber fabric 29 to ni~ 19.
To produce an area electrical insulating material in ribbon form with a thickness of 0.2 mm consisting of a foil of a thermosetting epoxy resin and mica powder on one surface and a fiber glass fabric web on the other surface, a muscovite-based mica powder with about 50% by weight having a grain size o 0.08 to 0.10 mm and about 50% by weight having a grain size of 1.5 to 1.8 mm is placed in storage tank 5 and an epoxy resin mixture 30 consisting of 7 parts by weight of epoxy resin with an epoxy equivalent of 200 and 3 parts by weight of epoxy resin with an epoxy equivalent o 420 is placed in heatable storage vessel lO. A latent amine hardener in solution in a reactive thinner 31 is placed in storage vessel 15 and the fiber glass fabric 29 has a thickness of 0.04 mm. The separating foils 28 made of polyethylene terephthalate have a thickness of 0.03 mm.
Mica powder 6 and liquid epoxy resin 30 are continuously fed together in a wei.ght ratio of 58:41 respectively through inlet 3 and are intimately mixed in first mixing ~one 32 of extruder l. At inlet 12, l part by weight of hardener solution 31 is added to the mica-resin mixture whereby extruder screws
The use of area insulatiny materials based on fine mica for the electrical insulation of coils and conductor rods of heavy-duty electrical machines is known and the said insulating materials are usually made of a support material such as glass fiber cloths or thermostable plastic foils bonded to a fine mica paper impregnated with a thermosetting resin which acts as a binder. The thermosetting resin in the said insula-ting material is in the B-state. The said area electrical insulating materials are applied to the element to be insula-ted such as a conductor rod as a tape or as a wide material and the coated element is heated in a coil press to cure the insulation and form the final product.
The preparation of the known area insulating materials is relatively expensive as the fine mica paper has to be prepared from mica in a suitable manner and then the support material and the fine mica paper are coated with the thermosetting resin and finally bonded together by calendering.
OBJECTS OF THE INVENTION
It is an object of the invention to provide an inexpensive method of producing an electrically insulating foil made of a hard-enable synthetic resin and electrical grade mica and the foil pro-duced thereby.
It is another object of the invention to provide a novel method of electrically insulating elements and the elements pro-duced thereby.
These and other objects and advantages of the invention will become obvious from the following detai]ed description.
3~
7~
THE INVENTION
The invention provides a process for the production of an electrical insulating foil comprising substantially a thin-layer of electrical grade mica powder and a hardenable syn-thetic resin with a thickness of 0.1 to 0.5 mm comprising the steps oE
forming a pas-te of electrical grade mlca powder and a hardenable substantially solvent free synthetic resin and optional fillers and/or reinforcement material, forming a strand of said paste and evenly distributing the pasty strand over the entrance of a calender or a ribbon press to reduce the strand thickness into a thin-layer 0.1 to 0.5 mm thick. The foil preferably has a thick-ness of about 0.2 mm.
The expression "electrical grade mica" means mica mater-ia] free of all electrically conductive compounds or materials such as metals and the preferred mica is muscovite or phlogopite based powder with a grain range of 0.03 to 2.8 mm. The pasty strand preferably contains 35 to 70% by weight, more preferably 45 to 65% by weight, of the mica powder and up to 20% by weight of fillers and/or reinforcing materials.
The hardenable synthetic resin mixture may be based on an epoxy resin, a polyester resin or a silicone resin. Preferred are mixtures of epoxy resins with epoxy equivalents of 150 to 800.
The hardenable resins will contain a hardener such as an amine dissolved in a reactive thinner such as diphenyl glycidyl e-ther, butanediol diglycidyl ether or more preferably a low viscosity cycloaliphatic epoxy resin. The hardenable synthetic resin may be used in the liquid state.
In a preferred embodiment of the invention, a mixture of '~
~ a~7~
resin and mica and optional filler and/or reinforcement materials is added to an extruder and the hardener is separately added to the extruder whereby mixing of the pasty material takes place in the extruder itself.
In a preferred embodiment of the invention, the pasty strand is supplied to the calender nip or the nip of the ribbon press between two incoming webs of sheet type ma-terial and prefer-ably the thin layer produced in the calender or ribbon press is permanently bonded to at leas-t one of the sheet type webs or advantageously a fiber fabric web is placed between the pasty - 2a -'' '~' ~3 ~ ~ a~
7~b~
strand and one of the webs of sheet material before entry into the calender nip or nip of the ribbon press. The fiber fabric web is permanently bonded to the thin foil produced thereby.
While the production of the resin foils using an extruder followed by calendering is known, one skilled in the art would not expect the calender-ing of a strand of a mixture of mica powder and resin would produce a foil or thin layer in which the mica powder particles are oriented essentially parallel to the foil surfaces by the thickness reduction of the strand in the calender.
The particle orientation of the mica par~icles parallel to the layer surfaces is similar to tha-t of mica in known mica paper which is important to obtain high electrical strength values.
Referring now to the drawing:
The Figure is a schematic view of an apparatus for carrying out the process of the invention.
The apparatus of the Figure comprises a heatable double screw extruder 1 with only one of the two screws 2 being illustrated in the drawing. The extruder housing is connected to feed hopper 4 by feed inlet 3 into which mi.ca powder 6 is metered from supply tank 5 by metering spiral 7 and inlet feed 3 is also connected via line 8 and proportioning pump 9 to heatable storage vessel 10 for the hardenable resin. A second feed inlet 12 offset relative to inlet 3 in the direction of arrow 10 is connected via line 13 and proportion-ing pump 14 to storage vessel 15 holding hardener solution 31. The extruder 1 is provided with orifice 16 for extrusion of a round strand and can pivot in oscillation at the point of orifice 16 as indicated by 17 in a direction perpendicular to the drawing plane.
Following the extruder is a calendar with a pair of heatable calendar rolls 18 which enclose nip 19 and provided with a draw-off device for foil product 20 comprising two guide rollers 21 and 22, a pair of draw-off rollers 23 and a winding device 24. The ca.lender is also provided with unrolling devices 25, 26 and 27 to feed two separate foils 28 in tape form and glass fiber fabric 29 to ni~ 19.
To produce an area electrical insulating material in ribbon form with a thickness of 0.2 mm consisting of a foil of a thermosetting epoxy resin and mica powder on one surface and a fiber glass fabric web on the other surface, a muscovite-based mica powder with about 50% by weight having a grain size o 0.08 to 0.10 mm and about 50% by weight having a grain size of 1.5 to 1.8 mm is placed in storage tank 5 and an epoxy resin mixture 30 consisting of 7 parts by weight of epoxy resin with an epoxy equivalent of 200 and 3 parts by weight of epoxy resin with an epoxy equivalent o 420 is placed in heatable storage vessel lO. A latent amine hardener in solution in a reactive thinner 31 is placed in storage vessel 15 and the fiber glass fabric 29 has a thickness of 0.04 mm. The separating foils 28 made of polyethylene terephthalate have a thickness of 0.03 mm.
Mica powder 6 and liquid epoxy resin 30 are continuously fed together in a wei.ght ratio of 58:41 respectively through inlet 3 and are intimately mixed in first mixing ~one 32 of extruder l. At inlet 12, l part by weight of hardener solution 31 is added to the mica-resin mixture whereby extruder screws
2 transports a uniform mixture of resin-mica-hardener solution to orifice 16.
The temperature of the mixture in the extruder is maintained at about 100C over the entire screw length and is lowered to 85 to 90C at orifice 16.
By oscillation of the extruder in the area of orifice 16 in a direction per-pendicular to the drawing plane, the pa.sty strand 33 continuously issuing from orifice 16 is supplied to nip 19 with even distribution over the total width thereof between two separating foils 28 fed from unwind.ing devices 25 and 27.
~9~
Fiber glass web 29 is supplied from unwinding device 26 between one of separat-ing foils 28 and pasty strand 33.
The material of the pasty strand 33 is continuously transformed between heated calender rollers 18 maintained at 75C into a thin foil which becomes permanently bonded to fiber glass fabric web 29. The flaky particles of mica powder in the foil are predominantly oriented parallel to the layer plane due to the calendering effest which is desired. The laminated material 20 emerging from the nip is drawn-off via guide rollers 21 and 22 with the aid of draw-off rollers 23 and is then wound at 24.
The separating foil 28 applied to fiber glass fabric 29 is removed from laminate 20 by a special rewinding device and the laminate is then ready for use as an area electrical insulating material after cutting into narrower strips, if desired.
The temperature contro] in the treatment of the mixture of mica powder, epoxy resin and hardener during the method is such that the resin is brought into the B state. Instead of being bonded with the glass fabric web 29, the ~hin -foil produced from the mixture of mica powder, epoxy resin and hardener can be bonded in the calendar also with other sheet type materials, in particular support materials such as plastic foils, synthetic fiber fabrics and the like. The method of the invention can advan~ageously be employed also quite generally for the production of foils which are to contain besides a hardenable resin mixture, instead of the mica powder or a part thereof, other Eillers and/or reinforcement substances such as carbon black, iron powder, reinforcement fibers and the like.
Various modifications of the products and processes of the invention may be made without departing from the spirit or scope thereof and it is to be understood that the invention is intended to be limited only as defined in the appended claims.
The temperature of the mixture in the extruder is maintained at about 100C over the entire screw length and is lowered to 85 to 90C at orifice 16.
By oscillation of the extruder in the area of orifice 16 in a direction per-pendicular to the drawing plane, the pa.sty strand 33 continuously issuing from orifice 16 is supplied to nip 19 with even distribution over the total width thereof between two separating foils 28 fed from unwind.ing devices 25 and 27.
~9~
Fiber glass web 29 is supplied from unwinding device 26 between one of separat-ing foils 28 and pasty strand 33.
The material of the pasty strand 33 is continuously transformed between heated calender rollers 18 maintained at 75C into a thin foil which becomes permanently bonded to fiber glass fabric web 29. The flaky particles of mica powder in the foil are predominantly oriented parallel to the layer plane due to the calendering effest which is desired. The laminated material 20 emerging from the nip is drawn-off via guide rollers 21 and 22 with the aid of draw-off rollers 23 and is then wound at 24.
The separating foil 28 applied to fiber glass fabric 29 is removed from laminate 20 by a special rewinding device and the laminate is then ready for use as an area electrical insulating material after cutting into narrower strips, if desired.
The temperature contro] in the treatment of the mixture of mica powder, epoxy resin and hardener during the method is such that the resin is brought into the B state. Instead of being bonded with the glass fabric web 29, the ~hin -foil produced from the mixture of mica powder, epoxy resin and hardener can be bonded in the calendar also with other sheet type materials, in particular support materials such as plastic foils, synthetic fiber fabrics and the like. The method of the invention can advan~ageously be employed also quite generally for the production of foils which are to contain besides a hardenable resin mixture, instead of the mica powder or a part thereof, other Eillers and/or reinforcement substances such as carbon black, iron powder, reinforcement fibers and the like.
Various modifications of the products and processes of the invention may be made without departing from the spirit or scope thereof and it is to be understood that the invention is intended to be limited only as defined in the appended claims.
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the production of an electrical insulating foil comprising substantially a thin-layer of electrical grade mica powder and a hardenable synthetic resin with a thickness of 0.1 to 0.5 mm comprising the steps of forming a paste of electrical grade mica powder and a hardenable substantially solvent free synthetic resin and optional fillers and/or reinforcement material, forming a strand of said paste and evenly distributing the pasty strand over the entrance of a calender or a ribbon press to reduce the strand thickness into a thin-layer 0.1 to 0.5 mm thick.
2. The process of claim 1 wherein the mica powder is based on muscovite or phlogopite.
3. The process of claim 1 wherein the paste contains 35 to 70% by weight of mica powder.
4. The process of claim 1 wherein the paste contains 45 to 65% by weight of mica powder.
5. The process of claim 1 wherein the paste contains up to 20% by weight of fillers and/or reinforcing materials.
6. The process of claim 1 wherein the resin is in the liquid state.
7. The process of claim 1 wherein the resin is an epoxy resin.
8. The process of claim 1 wherein the resin is a polyester resin.
9. The process of claim 1 wherein the resin is a silicone resin.
10. The process of claim 1 wherein the pasty strand is between two webs of sheet material while being calendered or pressed by a ribbon press.
11. The process of claim 10 wherein the pasty strand is permanently bonded to at least one of the webs of sheet material.
12. The process of claim 10 wherein a fiber fabric web is provided between the strand and web of sheet material and the fabric web and foil layer are permanently bonded together.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT2887/82 | 1982-07-27 | ||
AT0288782A AT387356B (en) | 1982-07-27 | 1982-07-27 | METHOD FOR PRODUCING FILMS SUITABLE AS ELECTRICAL INSULATING MATERIAL |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1199768A true CA1199768A (en) | 1986-01-28 |
Family
ID=3541873
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000433321A Expired CA1199768A (en) | 1982-07-27 | 1983-07-27 | Foil manufacture |
Country Status (10)
Country | Link |
---|---|
EP (1) | EP0113741B1 (en) |
JP (1) | JPS60500048A (en) |
AT (2) | AT387356B (en) |
AU (1) | AU565559B2 (en) |
CA (1) | CA1199768A (en) |
DE (1) | DE3368223D1 (en) |
IN (1) | IN158759B (en) |
IT (1) | IT1163849B (en) |
WO (1) | WO1984000515A1 (en) |
ZA (1) | ZA835471B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4769276A (en) * | 1985-12-13 | 1988-09-06 | Alsthom, S.A. | Mica-coated electrically insulating and fire-proofing adhesive tape especially suitable for electrical or optical fiber cable |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6991845B2 (en) * | 2002-12-13 | 2006-01-31 | E. I. Du Pont De Nemours And Company | Mica sheet and tape |
CN103700456B (en) * | 2014-01-02 | 2016-06-29 | 株洲时代电气绝缘有限责任公司 | A kind of mica tape production method not using organic solvent |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AT127811B (en) * | 1930-11-19 | 1932-04-25 | Ig Farbenindustrie Ag | Process for the production of shaped bodies from curable synthetic resins. |
LU41486A1 (en) * | 1961-04-06 | 1962-06-04 | ||
DE1257915B (en) * | 1961-07-22 | 1968-01-04 | Siemens Ag | Insulating material made from mica splits |
GB935439A (en) * | 1961-08-03 | 1963-08-28 | Ass Elect Ind | Solventless resin insulation |
GB991517A (en) * | 1963-04-18 | 1965-05-12 | Licentia Gmbh | Mica foil bonded with synthetic resin |
US3393426A (en) * | 1966-07-11 | 1968-07-23 | Adamson United Company | Lateral spreading extruder die assembly |
DE1629421A1 (en) * | 1966-12-27 | 1971-01-28 | Bayer Ag | Process and device for the continuous production of tapes or foils from thermoplastic plastics provided with fillers |
US3618753A (en) * | 1968-09-17 | 1971-11-09 | Minnesota Mining & Mfg | Large flake reconstituted mica insulation |
DE2006680A1 (en) * | 1969-02-13 | 1970-09-03 | Leesona Corp., Warwick, R.I. (V.St.A.) | Simultaneous extrusion of two plastics into adjacent |
DE1933281A1 (en) * | 1969-07-01 | 1971-01-14 | Klebetechnik Gmbh | Adhesive-coated insulation material produc- - tion |
BE755497A (en) * | 1969-08-30 | 1971-03-01 | Albert Ag Chem Werke | CONTINUOUS MANUFACTURING PROCESS OF PROFILES IN MOLD HARDENABLE SYNTHETIC MATERIALS |
DE2155382A1 (en) * | 1971-11-08 | 1973-05-17 | Voith Ag J M | Extruding thermosetting resins - eg polyesters with fibrous fillers to give stable profiles |
GB1532626A (en) * | 1974-11-12 | 1978-11-15 | British Industrial Plastics | Moulding of filled synthetic plastics moulding compositions |
DE2458614C3 (en) * | 1974-12-11 | 1979-10-25 | Werner & Pfleiderer, 7000 Stuttgart | Extruder-calender connection |
DD136368B1 (en) * | 1978-05-02 | 1981-03-25 | Plast Elastverarbeitungsmasch | EXTRUDER TOOL, ESPECIALLY FOR FEEDING A CALENDAR |
DE3028993A1 (en) * | 1979-08-02 | 1981-02-19 | Celanese Corp | FILLED EXTRUDED ENDLESS THERMOPLASTIC FLAT MATERIALS AND THEIR PRODUCTION |
-
1982
- 1982-07-27 AT AT0288782A patent/AT387356B/en not_active IP Right Cessation
-
1983
- 1983-07-22 EP EP83902232A patent/EP0113741B1/en not_active Expired
- 1983-07-22 AT AT83902232T patent/ATE24145T1/en not_active IP Right Cessation
- 1983-07-22 DE DE8383902232T patent/DE3368223D1/en not_active Expired
- 1983-07-22 JP JP58502405A patent/JPS60500048A/en active Pending
- 1983-07-22 WO PCT/AT1983/000022 patent/WO1984000515A1/en active IP Right Grant
- 1983-07-22 AU AU17745/83A patent/AU565559B2/en not_active Ceased
- 1983-07-25 IT IT22223/83A patent/IT1163849B/en active
- 1983-07-26 ZA ZA835471A patent/ZA835471B/en unknown
- 1983-07-27 CA CA000433321A patent/CA1199768A/en not_active Expired
-
1984
- 1984-01-30 IN IN28/BOM/84A patent/IN158759B/en unknown
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4769276A (en) * | 1985-12-13 | 1988-09-06 | Alsthom, S.A. | Mica-coated electrically insulating and fire-proofing adhesive tape especially suitable for electrical or optical fiber cable |
Also Published As
Publication number | Publication date |
---|---|
AU565559B2 (en) | 1987-09-17 |
ATA288782A (en) | 1988-06-15 |
WO1984000515A1 (en) | 1984-02-16 |
ATE24145T1 (en) | 1986-12-15 |
ZA835471B (en) | 1985-03-27 |
IN158759B (en) | 1987-01-17 |
AU1774583A (en) | 1984-02-23 |
IT1163849B (en) | 1987-04-08 |
AT387356B (en) | 1989-01-10 |
EP0113741A1 (en) | 1984-07-25 |
DE3368223D1 (en) | 1987-01-22 |
JPS60500048A (en) | 1985-01-17 |
IT8322223A0 (en) | 1983-07-25 |
EP0113741B1 (en) | 1986-12-10 |
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