EP0122967A2 - Flat insulating fabric and method for its production - Google Patents

Flat insulating fabric and method for its production Download PDF

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Publication number
EP0122967A2
EP0122967A2 EP83112236A EP83112236A EP0122967A2 EP 0122967 A2 EP0122967 A2 EP 0122967A2 EP 83112236 A EP83112236 A EP 83112236A EP 83112236 A EP83112236 A EP 83112236A EP 0122967 A2 EP0122967 A2 EP 0122967A2
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EP
European Patent Office
Prior art keywords
fibers
layers
weight
insulating material
polyester
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EP83112236A
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German (de)
French (fr)
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EP0122967A3 (en
EP0122967B1 (en
Inventor
Werner Schäfer
Dieter Dr. Groitzsch
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Carl Freudenberg KG
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Carl Freudenberg KG
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Classifications

    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
    • D04H1/542—Adhesive fibres
    • D04H1/55—Polyesters
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/4326—Condensation or reaction polymers
    • D04H1/4334—Polyamides
    • D04H1/4342—Aromatic polyamides
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/4326—Condensation or reaction polymers
    • D04H1/435—Polyesters
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
    • D04H1/559—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving the fibres being within layered webs
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
    • D04H1/74—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being orientated, e.g. in parallel (anisotropic fleeces)

Definitions

  • Flexible surface insulating materials are used, for example, in standard motors for phase separation, as slot insulation All-round insulation or deck slider used. They continue to be used as insulating material in dry-type transformers for layer insulation.
  • Multi-layer insulation materials based on polyester films film thickness: 0.03 mm to 0.3 mm
  • the multilayer structures usually have a thickness between 0.09 and 0.5 mm. They can be impregnated with insulating resins.
  • Non-laminate nonwovens For phase insulation in standard motors of insulation class F (155 ° C) and for layer insulation in transformers, thermally bound, i.e. Non-laminate nonwovens commonly used. These consist of polyester or aramid fibers, which are laid in a tangled fiber structure. The fiber thickness is usually 1.6 to 3.3 dtex. The ability of such nonwovens to be impregnated with insulating resins or insulating lacquers is very good, but the nonwovens have only relatively low dielectric strengths when not soaked.
  • the insulating materials are usually 0.1 to 0.7 mm thick. With a thickness of 0.2 mm e.g. the electrical breakdown voltage (ball / ball electrode) 0.6 to 1.8 KV.
  • the known, mostly single-layer nonwovens do not meet the above requirements. In particular, they have an insufficient dielectric strength when not soaked. It is therefore important to use aramid paper and multilayer insulating materials, e.g. based on polyester film as a carrier of electrical dielectric strength. In addition to its property as a carrier of the dielectric properties, the polyester film is also to be regarded as a component providing stiffness, the nonwovens or aramid papers laminated on one or both sides having the mechanical properties, e.g. influence the tear or tear strength and serve as carrier media for the insulating resins or varnishes.
  • the invention is based on the object of developing a flexible surface insulating material with a high dielectric strength, which is nevertheless stiff and cannot be excessively compressed.
  • the dielectric strength should be at least 30 KV / mm.
  • the surface insulating material should be free of laminating adhesives and should be soaked with insulating liquids. Even when not soaked, the insulating material should have a significantly improved electrical dielectric strength.
  • the object of the invention is achieved by the surface insulating material set out in the claims. According to the invention, a method for producing these substances is also proposed.
  • the surface insulating material is always made up of several, adhesive-free by calendering with interconnected nonwoven layers.
  • the stretched polyester and / or aramid fibers of the nonwoven are mixed with undrawn polyester fibers as binding fibers.
  • Polyethylene glycol terephthalate fibers are preferred as polyester fibers.
  • Polyester fibers based on poly (1,4-dimethylol) cyclohexane terephthalate are also very suitable.
  • Preferred aramid fibers are aramids based on aromatic poly-1,3-phenylene isophthalamide and poly-p-phenylene terephthalamide.
  • the multilayer structure consists of at least two layers. At least three layers are preferred. It is expedient to lay down the fibers of the piles which are later consolidated to form the nonwoven fabric in different orientations.
  • layers of longitudinal and transverse pile are alternately deposited with the aid of carding or carding devices.
  • the outer layers are longitudinal, while the inner layer is transverse.
  • the pile layers are then thermally consolidated to form the surface insulating material according to the invention.
  • the middle layer consists of a wet-laid nonwoven fabric of the fiber composition defined above.
  • the outer Nonwovens are thermally bonded nonwovens, formed by carding or carding machines and in particular spunbonded nonwovens.
  • a line pressure of the calender between 100 and 180 kp / cm is expediently maintained during the consolidation.
  • the calender temperature of the steel roller is 190 to 220 ° C.
  • Line pressure and calender temperature can be varied according to the product manufactured.
  • a particularly good result is e.g. at a line pressure of the calender of 140 to 160 kp / cm and a roller temperature of 210 ° C when a three-layer structure with a final thickness of 1.2 mm is produced.
  • the mixtures which are expedient for the respective area of application are selected, and according to the application, the term "fibers" means both staple fibers and continuous fibers. It is preferred if the outer layers each contain fewer binding fibers.
  • a mixture of 85 to 30% by weight, based on the total weight of the fibers, of stretched polyester and / or aramid fibers of a strength of 1.0 to 6.7 dtex together with 15 to 70% by weight of undrawn polyester fibers has proven useful Thickness from 0.8 to 8 dtex.
  • the outer layers composed in this way are generally longitudinal.
  • the inner layer which is expediently laid crosswise, consists of 50 to 100% by weight of undrawn polyester fibers, which are also binding fibers. These binding fibers have a thickness of 0.5 to 6.7 dtex. They are optionally used together with up to 50% by weight of stretched polyester and / or aramid fibers.
  • the weight of the cover layer is between 10 and 100 g / m2, with a total thickness of 0.2 mm, for example, about 30 g / m2.
  • a transversely laid middle layer of 80 to 100% by weight of undrawn polyester fibers (thickness 0.8 dtex) is then arranged between these longitudinally oriented layers.
  • the weight of this layer is between 50 and 350 g / sqm. With a total thickness of 0.2 mm, the weight is about 150 g / sqm.
  • the surface insulating material can be soaked excellently with conventional insulating liquids and is free of laminating adhesives due to its special structure and the proposed hardening process.
  • the special fiber arrangement ensures particularly high mechanical strength.
  • the always very high rigidity can be varied depending on the structure and thickness.
  • the compressibility is optimally low.
  • the following example shows a preferred manufacturing process for the surface insulating material.
  • a longitudinally oriented layer of a mixture of 30% by weight of undrawn polyethylene glycol terephthalate fibers is first deposited together with 70% by weight of drawn polyethylene glycol terephthalate fibers.
  • the strength of the drawn fibers is 1.7 dtex, while the undrawn fibers are 5.7 dtex strong.
  • the weight of the pile layer is 30 g / sqm.
  • a cross-laid pile of 90% by weight of undrawn polyethylene glycol terephthalate fibers with a thickness of 0.8 dtex is placed on this layer.
  • the weight of this layer is 90 g / m 2 .
  • a further longitudinally oriented layer of the composition specified above is then applied.
  • the stretching of the polyethylene glycol terephthalate fibers is 3 to 4 times that of the undrawn polyethylene glycol terephthalate fibers.
  • the three-layer structure is passed through a calender, the roll temperature of which is 210 ° C. With a line pressure of 150 kp / cm, the multilayer structure is solidified. It has a final thickness of 1.2 mm. The dielectric strength is about 35 KV / mm.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Laminated Bodies (AREA)
  • Organic Insulating Materials (AREA)

Abstract

1. A flexible sheetlike insulating material of high breakdown resistance, composed of a nonwoven comprising a plurality of drawn and undrawn polyester fibre layers bonded together without adhesive by application of heat and pressure, characterized in that there are provided layers of drawn polyester and/or aramid fibres and of undrawn polyester fibres as binding fibres, these layers being bonded to one another by the application of heat and pressure, and that the fibres making up the layers have been differently orientated from layer to layer, the outer layers of the nonwoven having been orientated in the longitudinal direction and there being provided at least one inner layer of transversely orientated fibres that contains from 50 to 100 % by weight, based on the total weight of the fibres, of undrawn polyester fibres of from 0.5 to 6.7 dtex and up to 50 % by weight of drawn polyester and/or aramid fibres.

Description

Die Erfindung betrifft einen flexiblen Flächenisolierstoff, der aus mehreren Schichten aufgebaut ist. Der Flächenisolierstoff hat eine besonders hohe Durchschlagfestigkeit. Es wird weiterhin ein Verfahren zur llerstellung eines solchen Flächenisolierstoffes vorgeschlagen.The invention relates to a flexible surface insulating material which is composed of several layers. The surface insulating material has a particularly high dielectric strength. A method for producing such a surface insulating material is also proposed.

Flexible Flächenisolierstoffe werden beispielsweise bei Normmotoren zur Phasentrennung, als Nutisolation, als Rundumisolation oder Deckschieber verwendet. Sie werden weiterhin als Isolierstoff bei Trockentransformatoren zur Lagenisolation eingesetzt.Flexible surface insulating materials are used, for example, in standard motors for phase separation, as slot insulation All-round insulation or deck slider used. They continue to be used as insulating material in dry-type transformers for layer insulation.

Auf nassem Wege hergestellte Papiere auf der Basis aromatischer Polyamidfasern und auch Mehrschichtisolierstoffe, die aus derartigen Papieren, die mit Folien aus Poly- äthylenglykolterephthalaten kaschiert sind, sind bekannte Handelsprodukte. Es sind auch Mehrschichtisolierstoffe bekannt auf Basis von Polyesterfolien (Folienstärken: 0,03 mm bis 0,3 mm), die mit dünnen Vliesstoffen (in Stärken von 0,025 mm bis 0,125 mm), insbesondere mit Vliesstoffen, die Polyäthylenglykolterephthalatfasern oder Aramidfasern enthalten, kaschiert sind. Die Mehrschichtgebilde haben meist eine Dicke zwischen 0,09 und 0,5 mm. Sie können mit Isolierharzen getränkt werden.Papers produced on a wet basis on the basis of aromatic polyamide fibers and also multilayer insulating materials which are made from such papers and which are laminated with films made from polyethylene glycol terephthalates are known commercial products. Multi-layer insulation materials based on polyester films (film thickness: 0.03 mm to 0.3 mm) are also known, which are laminated with thin nonwovens (in thicknesses from 0.025 mm to 0.125 mm), in particular with nonwovens containing polyethylene glycol terephthalate fibers or aramid fibers . The multilayer structures usually have a thickness between 0.09 and 0.5 mm. They can be impregnated with insulating resins.

Zur Phasenisolation bei Normmotoren der Isolierstoffklasse F (155° C) und zur Lagenisolation bei Transformatoren sind auch thermisch gebundene, d.h. kaschierklebstofffreie Vliesstoffe gebräuchlich. Diese bestehen aus Polyester-oder Aramidfasern, die in Wirrfaserstruktur abgelegt sind. Die Faserstärke beträgt in der Regel 1,6 bis 3,3 dtex. Die Tränkfähigkeit derartiger Vliesstoffe mit Isolierharzen oder Isolierlacken ist sehr gut, jedoch weisen die Vliesstoffe im ungetränkten Zustand nur relativ geringe dielektrische Festigkeiten auf. Die Isolierstoffe sind üblicherweise 0,1 bis 0,7 mm dick. Bei 0,2 mm Dicke beträgt z.B. die elektrische Durchschlagspannung (Kugel/Kugel-Elektrode) 0,6 bis 1,8 KV.For phase insulation in standard motors of insulation class F (155 ° C) and for layer insulation in transformers, thermally bound, i.e. Non-laminate nonwovens commonly used. These consist of polyester or aramid fibers, which are laid in a tangled fiber structure. The fiber thickness is usually 1.6 to 3.3 dtex. The ability of such nonwovens to be impregnated with insulating resins or insulating lacquers is very good, but the nonwovens have only relatively low dielectric strengths when not soaked. The insulating materials are usually 0.1 to 0.7 mm thick. With a thickness of 0.2 mm e.g. the electrical breakdown voltage (ball / ball electrode) 0.6 to 1.8 KV.

Hier ergibt sich der Nachteil, daß insbesondere bei der Phasenisolation kleinerer Normmotoren bei Vliesstoffen der üblichen Dicke von etwa 0,22 mm die Spannungsfestigkeit im ungetränkten Zustand nicht ausreicht. Nach nationalen (VDE) und internationalen (IEC) Richtlinien soll jedoch am ungetränkten Stator eines Normmotors eine Prüfung der Spannungsfestigkeit zwischen Phase/Phase bzw. Phase/Masse (sogenannte "Weißprüfung") mit der zweifachen Nennspannung plus 1000 Volt erfolgen (Up = 2 x UN + 1 KV).The disadvantage here is that, in particular in the phase insulation of smaller standard motors with nonwovens of the usual thickness of about 0.22 mm, the dielectric strength in the unimpregnated state is insufficient. According to national (VDE) and international (IEC) guidelines, however, the dielectric strength between phase / phase or phase / mass (so-called "white test") should be carried out on the unimpregnated stator of a standard motor with twice the nominal voltage plus 1000 volts (Up = 2 x U N + 1 KV).

Dies bedeutet bei einem Stator eines dreiphasigen Drehstrommotors eine Prüfspannung von 2 x 360 V + 1 KV = 1,72 KV.For a stator of a three-phase AC motor, this means a test voltage of 2 x 360 V + 1 KV = 1.72 KV.

Die bekannten, meist einschichtigen Vliesstoffe erfüllen die vorstehend angegebenen Anforderungen nicht. Insbesondere weisen sie ungetränkt eine unzureichende Durchschlagfestigkeit auf. Man ist deshalb auf die Verwendung von Aramidpapieren sowie von Mehrschichtisolierstoffen, z.B. auf Polyesterfolienbasis als Träger der elektrischen Spannungsfestigkeit angewiesen. Die Polyesterfolie ist neben ihrer Eigenschaft als Träger der dielektrischen Eigenschaften auch als steifigkeitsgebende Komponente anzusehen, wobei die ein- oder beidseitig aufkaschierten Vliesstoffe oder Aramidpapiere die mechanischen Eigenschaften, z.B. die Einreiß- oder Weiterreißfestigkeit beeinflussen sowie als Trägermedien für die Isolierharze oder -lacke dienen.The known, mostly single-layer nonwovens do not meet the above requirements. In particular, they have an insufficient dielectric strength when not soaked. It is therefore important to use aramid paper and multilayer insulating materials, e.g. based on polyester film as a carrier of electrical dielectric strength. In addition to its property as a carrier of the dielectric properties, the polyester film is also to be regarded as a component providing stiffness, the nonwovens or aramid papers laminated on one or both sides having the mechanical properties, e.g. influence the tear or tear strength and serve as carrier media for the insulating resins or varnishes.

Die Kaschierung der Folien mit Vliesstoffen oder Aramidpapieren ist sehr arbeitsaufwendig und erfordert gezielte explosionsgeschützte Kaschieranlagen, weil die verwendeten Klebstoffe meist in organischen Lösungsmitteln gelöst sind. Je nach Art und Verarbeitung der Kaschierklebstoffe sind überdies negative Wechselwirkungen mit den Tränkmitteln und den elektrischen Aggregaten zu befürchten. Auch Störungen des thermischen Eigenschaftsprofils der Verbundmaterialien treten häufig auf.The lamination of the foils with nonwovens or aramid papers is very labor intensive and requires targeted explosion-proof lamination systems because the adhesives used are mostly dissolved in organic solvents. Depending on the type and processing of the laminating adhesive, there are also negative interactions with the impregnating agents and fear the electrical aggregates. Disturbances in the thermal properties profile of the composite materials also occur frequently.

Man hat deshalb nach Flächenisolierstoffen gesucht, die einerseits kaschiermittelfrei sind, andererseits die gewünschte Durchschlagfestigkeit aufweisen und überdies keine Wechselwirkungen mit Tränkflüssigkeiten der elektrischen Aggregaten aufweisen. Die bekannten thermisch gebundenen Vliesstoffe auf Polyester- bzw. Aramidbasis haben sich in der geeigneten Dicke von etwa 0,15 bis 0,7 mm zur Nutisolation beispielsweise als ungeeignet erwiesen, weil die elektrische Spannungsfestigkeit zu gering ist und die Produkte überdies in unerwünschtem Maße zusammengedrückt werden. Derartige Vliesstoffe sind überdies für eine automatische Einbringung als Nuthülsen oder Deckschieber nicht steif genug. Man ist also auch für diesen-Anwendungsbereich auf kalandrierte Aramidpapiere oder flexible Mehrschichtisolierstoffe auf der Basis von Polyesterfolien und Aramidpapieren bzw. Vliesstoffen, die mit Kaschierkleber versehen sind, angewiesen.Therefore, a search was made for surface insulating materials which on the one hand are free of laminating agents, on the other hand have the desired dielectric strength and, moreover, have no interactions with impregnating liquids of the electrical units. The known thermally bonded nonwovens based on polyester or aramid have proven to be unsuitable, for example, in the suitable thickness of about 0.15 to 0.7 mm for groove insulation, because the dielectric strength is too low and the products are also compressed to an undesirable extent . Such nonwovens are also not stiff enough for automatic insertion as grooved sleeves or slide gates. For this area of application, too, one is dependent on calendered aramid papers or flexible multilayer insulating materials based on polyester films and aramid papers or nonwovens, which are provided with laminating adhesive.

Der Erfindung liegt nun die Aufgabe zugrunde, einen flexiblen Flächenisolierstoff mit einer hohen Durchschlagfestigkeit zu entwickeln, der dabei trotzdem steif ist und sich nicht übermäßig zusammendrücken läßt. Die Durchschlagfestigkeit soll wenigstens 30 KV/mm betragen. Der Flächenisolierstoff soll kaschierklebstofffrei sein und sich gut mit Isolierflüssigkeiten tränken lassen. Auch im ungetränkten Zustand soll der Isolierstoff eine deutlich verbesserte elektrische Spannungsfestigkeit zeigen.The invention is based on the object of developing a flexible surface insulating material with a high dielectric strength, which is nevertheless stiff and cannot be excessively compressed. The dielectric strength should be at least 30 KV / mm. The surface insulating material should be free of laminating adhesives and should be soaked with insulating liquids. Even when not soaked, the insulating material should have a significantly improved electrical dielectric strength.

Die erfindungsgemäß gestellte Aufgabe wird durch den in den Patentansprüchen wiedergegebenen Flächenisolierstoff gelöst. Erfindungsgemäß wird weiterhin ein Verfahren zur Herstellung dieser Stoffe vorgeschlagen.The object of the invention is achieved by the surface insulating material set out in the claims. According to the invention, a method for producing these substances is also proposed.

Der Flächenisolierstoff ist stets aus mehreren, klebstofffrei durch Kalandrieren mit einander verbundenen Vliesstoffschichten aufgebaut. Die verstreckten Polyester- und/oder Aramidfasern des Vliesstoffes sind mit unverstreckten Polyesterfasern als Bindefasern vermischt. Als Polyesterfasern werden Polyäthylenglyköltercphthalatfasern bevorzugt. Gut geeignet sind weiterhin Polyesterfasern auf Basis Poly-(1,4-dimethylol-)cyclohexanterephthalat. Bevorzugte Aramidfasern sind Aramide auf Basis aromatischer Poly-1,3-phenylenisophthalamid sowie Poly-p-phenylenterephthalamid.The surface insulating material is always made up of several, adhesive-free by calendering with interconnected nonwoven layers. The stretched polyester and / or aramid fibers of the nonwoven are mixed with undrawn polyester fibers as binding fibers. Polyethylene glycol terephthalate fibers are preferred as polyester fibers. Polyester fibers based on poly (1,4-dimethylol) cyclohexane terephthalate are also very suitable. Preferred aramid fibers are aramids based on aromatic poly-1,3-phenylene isophthalamide and poly-p-phenylene terephthalamide.

Das Mehrschichtgebilde besteht aus mindestens zwei Schichten. Bevorzugt werden mindestens drei Schichten. Es ist zweckmäßig, die Fasern der später zu dem Vliesstoff verfestigten Flore jeweils unterschiedlich orientiert abzulegen. So wird nach dem bevorzugten Verfahren zur Herstellung der Flächenisolierstoffe mit Hilfe von Karden- oder Krempeleinrichtungen abwechselnd Schichten längs- und.querorientierter Flore abgelegt. Bei einem dreischichtigen Aufbau sind die äußeren Schichten längsorientiert, während die innere Schicht quergelegt ist. Mit Hilfe eines beheizten Kalanders werden die Florschichten dann thermisch zu dem erfindungsgemäßen Flächenisolierstoff verfestiqt.The multilayer structure consists of at least two layers. At least three layers are preferred. It is expedient to lay down the fibers of the piles which are later consolidated to form the nonwoven fabric in different orientations. Thus, according to the preferred method for producing the surface insulation materials, layers of longitudinal and transverse pile are alternately deposited with the aid of carding or carding devices. With a three-layer structure, the outer layers are longitudinal, while the inner layer is transverse. With the help of a heated calender, the pile layers are then thermally consolidated to form the surface insulating material according to the invention.

Nach einer weiteren bevorzugten Ausführung besteht die Mittelschicht aus einem naßgelegten Vliesstoff der vorstehend definierten Faser-Zusammensetzung. Die äußeren Vliesstoffe sind thermisch gebundene Vliesstoffe, gebildet über Karden- oder Krempelanlagen und insbesondere Spinnvliesstoffe.According to a further preferred embodiment, the middle layer consists of a wet-laid nonwoven fabric of the fiber composition defined above. The outer Nonwovens are thermally bonded nonwovens, formed by carding or carding machines and in particular spunbonded nonwovens.

Bei der Verfestigung wird zweckmäßig ein Liniendruck des Kalanders zwischen 100 und 180 kp/cm eingehalten. Die Kalandertemperatur der Stahlwalze beträgt 190 bis 220° C.A line pressure of the calender between 100 and 180 kp / cm is expediently maintained during the consolidation. The calender temperature of the steel roller is 190 to 220 ° C.

Liniendruck und Kalandertemperatur können dem hergestellten Produkt entsprechend variiert werden. Ein besonders gutes Ergebnis wird so z.B. bei einem Liniendruck des Kalanders von 140 bis 160 kp/cm und einer Walzentemperatur von 210° C erreicht, wenn ein dreischichtiges Gebilde mit 1,2 mm Endstärke hergestellt wird.Line pressure and calender temperature can be varied according to the product manufactured. A particularly good result is e.g. at a line pressure of the calender of 140 to 160 kp / cm and a roller temperature of 210 ° C when a three-layer structure with a final thickness of 1.2 mm is produced.

Unter den angegebenen Faserarten werden die für den je- weiligen Anwendungsbereich zweckmäßigen Mischungen ausgewählt, wobei anmeldungsgemäß unter der Bezeichnung "Fasern" sowohl Stapelfasern als auch Endlosfasern verstanden werden. Es ist bevorzugt, wenn die äußeren Schichten jeweils weniger Bindefasern enthalten. Bewährt hat sich eine Mischung aus 85 bis 30 Gew.%, bezogen auf das Gesamtgewicht der Fasern, an verstreckten Polyester- und/oder Aramidfasern einer Stärke von 1,0 bis 6,7 dtex zusammen mit 15 bis 70 Gew.% unverstreckten Polyesterfasern einer Stärke von 0,8 bis 8 dtex. Die so zusammengesetzten äußeren Schichten sind in der Regel längsorientiert. Die innere Schicht, die zweckmäßig quergelegt ist, besteht aus 50 bis 100 Gew.% unverstreckten Polyesterfasern, die gleichzeitig Bindefasern sind. Diese Bindefasern weisen eine Stärke von 0,5 bis 6,7 dtex auf. Sie werden gegebenenfalls zusammen mit bis zu 50 Gew.% verstreckten Polyester- und/oder Aramidfasern verwendet.From the specified types of fibers, the mixtures which are expedient for the respective area of application are selected, and according to the application, the term "fibers" means both staple fibers and continuous fibers. It is preferred if the outer layers each contain fewer binding fibers. A mixture of 85 to 30% by weight, based on the total weight of the fibers, of stretched polyester and / or aramid fibers of a strength of 1.0 to 6.7 dtex together with 15 to 70% by weight of undrawn polyester fibers has proven useful Thickness from 0.8 to 8 dtex. The outer layers composed in this way are generally longitudinal. The inner layer, which is expediently laid crosswise, consists of 50 to 100% by weight of undrawn polyester fibers, which are also binding fibers. These binding fibers have a thickness of 0.5 to 6.7 dtex. They are optionally used together with up to 50% by weight of stretched polyester and / or aramid fibers.

Nach dem Kalandrieren erhält man dann steife, jedoch flexible Flächenisolierstoffe einer Gesamtdicke zwischen 0,1 und 0,7 mm. Bevorzugt werden Flächengebilde von 0,2 bis 0,5 mm hergestellt. Bei diesen Stoffen beträgt die Durchschlagspannung 4,0 bis 8,0 KV. Die Durchschlagfestigkeit ist in jedem Falle größer als 30 KV/mm. Besonders bewährt haben sich Dreischichtgebilde aus außen angeordneten längsgelegten Vliesen aus 80 bis 60 Gew.% verstreckten Polyester- oder Aramidfasern zusammen mit 20 bis 40 Gew.% unverstreckten Polyesterfasern. Die Faserdicke beträgt hierbei 1,7 dtex bei den verstreckten Polyester- bzw. Aramidfasern. Die Dicke der unverstreckten Polyesterfasern beträgt 5,7 dtex. Das Gewicht der Deckschicht liegt dabei jeweils zwischen 10 und 100 g/qm, bei einer Gesamtdicke von 0,2 mm beispielsweise bei ca. 30 g/qm. Zwischen diesen längsorientierten Schichten ist dann eine quergelegte Mittelschicht aus 80 bis 100 Gew.% unverstreckten Polyesterfasern (Dicke 0,8 dtex) angeordnet. Das Gewicht dieser Schicht liegt zwischen 50 und 350 g/qm. Bei einer Gesamtdicke von 0,2 mm beträgt das Gewicht etwa 150 g/qm.After calendering, rigid but flexible surface insulating materials with a total thickness between 0.1 and 0.7 mm are then obtained. Flat structures of 0.2 to 0.5 mm are preferably produced. The breakdown voltage for these substances is 4.0 to 8.0 KV. The dielectric strength is in any case greater than 30 KV / mm. Three-layer structures made of longitudinally arranged nonwovens made from 80 to 60% by weight of stretched polyester or aramid fibers together with 20 to 40% by weight of undrawn polyester fibers have proven particularly useful. The fiber thickness here is 1.7 dtex for the stretched polyester or aramid fibers. The thickness of the undrawn polyester fibers is 5.7 dtex. The weight of the cover layer is between 10 and 100 g / m2, with a total thickness of 0.2 mm, for example, about 30 g / m2. A transversely laid middle layer of 80 to 100% by weight of undrawn polyester fibers (thickness 0.8 dtex) is then arranged between these longitudinally oriented layers. The weight of this layer is between 50 and 350 g / sqm. With a total thickness of 0.2 mm, the weight is about 150 g / sqm.

Der Flächenisolierstoff läßt sich ausgezeichnet mit üblichen Isolierflüssigkeiten tränken und ist aufgrund seines speziellen Aufbaus und des vorgeschlagenen Verfestigungsverfahrens frei von Kaschierklebstoffen. Durch die spezielle Faseranordnung ist eine besonders hohe mechanische Festigkeit gegeben. Die stets sehr hohe Steifigkeit läßt sich je nach Aufbau und Dicke variieren. Die Kompressibilität ist in optimalem Maße gering.The surface insulating material can be soaked excellently with conventional insulating liquids and is free of laminating adhesives due to its special structure and the proposed hardening process. The special fiber arrangement ensures particularly high mechanical strength. The always very high rigidity can be varied depending on the structure and thickness. The compressibility is optimally low.

Das nachfolgende Beispiel zeigt ein bevorzugtes Herstellungsverfahren für den Flächenisolierstoff.The following example shows a preferred manufacturing process for the surface insulating material.

Beispielexample

Mit einer Kardenanlage wird zunächst eine längsorientierte Schicht einer Mischung aus 30 Gew.% unverstreckten Polyäthylenglykolterephthalatfasern zusammen mit 70 Gew.% verstreckten Polyäthylenglykolterephthalatfasern abgelegt. Die Stärke der verstreckten Fasern liegt bei 1,7 dtex, während die unverstreckten Fasern 5,7 dtex stark sind. Das Gewicht der Florschicht beträgt 30 g/qm.With a carding machine, a longitudinally oriented layer of a mixture of 30% by weight of undrawn polyethylene glycol terephthalate fibers is first deposited together with 70% by weight of drawn polyethylene glycol terephthalate fibers. The strength of the drawn fibers is 1.7 dtex, while the undrawn fibers are 5.7 dtex strong. The weight of the pile layer is 30 g / sqm.

Auf diese Schicht wird ein quergelegter Flor aus 90 Gew.% unverstreckten Polyäthylenglykolterephthalatfasern einer Stärke von 0,8 dtex abgelegt. Das Gewicht dieser Schicht beträgt 90 g/m2.A cross-laid pile of 90% by weight of undrawn polyethylene glycol terephthalate fibers with a thickness of 0.8 dtex is placed on this layer. The weight of this layer is 90 g / m 2 .

Es wird dann eine weitere längsorientierte Schicht der oben angegebenen Zusammensetzung aufgebracht.A further longitudinally oriented layer of the composition specified above is then applied.

Die Verstreckung der Polyäthylenglykolterephthalatfasern beträgt das 3- bis 4fache der unverstreckten Polyäthylenglykolterephthalatfasern.The stretching of the polyethylene glycol terephthalate fibers is 3 to 4 times that of the undrawn polyethylene glycol terephthalate fibers.

Das dreischichtige Gebilde wird durch einen Kalander geführt, dessen Walzentemperatur 210° C beträgt. Bei einem Liniendruck von 150 kp/cm wird das Mehrschichtgebilde verfestigt. Es weist eine Endstärke von 1,2 mm auf. Die Durchschlagfestigkeit beträgt etwa 35 KV/mm.The three-layer structure is passed through a calender, the roll temperature of which is 210 ° C. With a line pressure of 150 kp / cm, the multilayer structure is solidified. It has a final thickness of 1.2 mm. The dielectric strength is about 35 KV / mm.

Claims (6)

1. Flexibler Flächenisolierstoff mit einer Durchschlagfestigkeit von mehr als 30 KV/mm, gekennzeichnet durch mehrere klebstofffrei unter Anwendung von Hitze und Druck miteinander verbundene Vliesstoffschichten, die jeweils aus verstreckten Polyester- und/oder Aramidfasern sowie aus unverstreckten Polyesterfasern als Bindefasern aufgebaut sind, wobei die äußeren Vliesstoffschichten längsorientiert sind und wengistens eine innere Schicht aus querorientierten Fasern vorgesehen ist, die 50 bis 100 Gew.%, bezogen auf das Gesamtgewicht der Fasern, unverstreckte Polyesterfasern von 0,5 bis 6,7 dtex enthält und bis zu 50 Gew.% verstreckte Polyester- und/oder Aramidfasern.1.Flexible surface insulating material with a dielectric strength of more than 30 KV / mm, characterized by several adhesive-free nonwoven layers bonded together using heat and pressure, which are each composed of stretched polyester and / or aramid fibers and undrawn polyester fibers as binding fibers, the Outer nonwoven layers are longitudinally oriented and an inner layer of transversely oriented fibers is provided, which contains 50 to 100% by weight, based on the total weight of the fibers, of undrawn polyester fibers of 0.5 to 6.7 dtex and stretched up to 50% by weight Polyester and / or aramid fibers. 2. Flächenisolierstoff nach Anspruch 1, dadurch gekennzeichnet, daß er aus drei Vliesstoffschichten besteht und die äußeren längsorientierten Schichten aus einer Mischung von 85 bis 30 Gew.°ö, bezogen auf das Gesamtgewicht der Fasern, an verstreckten Polyester- und/oder Aramidfasern von 1,0 bis 6,7 dtex und 15 bis 70 Gew.% unverstreckten Polyesterfasern von 0,8 bis 8 dtex aufgebaut sind.2. surface insulating material according to claim 1, characterized in that it consists of three nonwoven layers and the outer longitudinal layers of a mixture of 85 to 30 wt.% Ö, based on the total weight of the fibers, of stretched polyester and / or aramid fibers of 1 , 0 to 6.7 dtex and 15 to 70% by weight of undrawn polyester fibers of 0.8 to 8 dtex. 3. Flächenisolierstoff nach einem der Ansprüche 1 oder 2, dadurch gekennzeichnet, daß eine innere querorientierte Schicht vorgesehen ist, die 50 bis 100 Gew.%, bezogen auf das Gesamtgewicht der Fasern, unverstreckte Polyesterfasern von 0,8 dtex enthält.3. Surface insulating material according to one of claims 1 or 2, characterized in that an inner, transversely oriented layer is provided which contains 50 to 100% by weight, based on the total weight of the fibers, of undrawn polyester fibers of 0.8 dtex. '4. Flächenisolierstoff nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß die innere Schicht ein naßgelegter Vliesstoff ist.'4. Surface insulating material according to one of claims 1 to 3, characterized in that the inner layer is a wet-laid nonwoven. 5. Flächenisolierstoff nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß die äußeren Schichten Spinnvliesstoffe sind.5. surface insulating material according to one of claims 1 to 4, characterized in that the outer layers are spunbonded nonwovens. 6. Verfahren zur Herstellung eines Flächenisolierstoffes nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß mit Hilfe bekannter Einrichtungen abwechselnd Schichten längs- und querorientierter Flore abgelegt werden, wobei die äußeren Schichten längsorientiert sind und wenigstens eine innere Schicht querorientiert ist, und daß die aufeinanderliegenden Flore dann mit einem beheizten Kalander bei einem Liniendruck von 150 bis 180 kp/cm und einer Walzentemperatur von 190 bis 220°C verfestigt und so zu einem steifen flexiblen Flächengebilde miteinander verbunden werden.6. A method for producing a surface insulating material according to one of claims 1 to 6, characterized in that layers of longitudinal and transverse oriented sheets are deposited alternately with the aid of known devices, the outer layers being longitudinally oriented and at least one inner layer being transverse oriented, and that the superimposed piles are then solidified with a heated calender at a line pressure of 150 to 180 kp / cm and a roller temperature of 190 to 220 ° C and thus joined together to form a rigid, flexible sheet.
EP83112236A 1983-04-22 1983-12-06 Flat insulating fabric and method for its production Expired EP0122967B1 (en)

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DE3314691 1983-04-22
DE3314691A DE3314691C1 (en) 1983-04-22 1983-04-22 Surface insulating material and process for its manufacture

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0199901A2 (en) * 1985-03-29 1986-11-05 Firma Carl Freudenberg Supporting layer for a semi-permeable membrane and method for making it
WO2009024396A1 (en) * 2007-08-22 2009-02-26 Eswegee Vliesstoff Gmbh Base non-woven fibre for trilaminates
WO2009024393A1 (en) * 2007-08-22 2009-02-26 Eswegee Vliesstoff Gmbh Method for producing a base non-woven fibre as support for a coating
WO2013187956A1 (en) * 2012-06-15 2013-12-19 3M Innovative Properties Company Electrical insulation material
US9437348B2 (en) 2010-12-17 2016-09-06 3M Innovative Properties Company Electrical insulation material
EP3088581B1 (en) 2013-12-27 2020-02-26 Nihon Tokushu Toryo Co., Ltd. Felt, soundproofing material and method for producing soundproofing material

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DE1117079B (en) * 1955-09-02 1961-11-16 Minnesota Mining & Mfg Flexible fleece made from combined polyester fibers
FR1518995A (en) * 1967-02-17 1968-03-29 Non-woven textile product and its manufacturing process
FR2307345A1 (en) * 1975-04-10 1976-11-05 Rhone Poulenc Textile Electrical insulator is felt of polyester fibres - having higher density surface skin formed by melting fibres
DE2533017B2 (en) * 1975-03-14 1978-11-16 The Kendall Co., Walpole, Mass. (V.St.A.) Electrical insulating material consisting of a fiber fleece

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1117079B (en) * 1955-09-02 1961-11-16 Minnesota Mining & Mfg Flexible fleece made from combined polyester fibers
FR1518995A (en) * 1967-02-17 1968-03-29 Non-woven textile product and its manufacturing process
DE2533017B2 (en) * 1975-03-14 1978-11-16 The Kendall Co., Walpole, Mass. (V.St.A.) Electrical insulating material consisting of a fiber fleece
FR2307345A1 (en) * 1975-04-10 1976-11-05 Rhone Poulenc Textile Electrical insulator is felt of polyester fibres - having higher density surface skin formed by melting fibres

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0199901A2 (en) * 1985-03-29 1986-11-05 Firma Carl Freudenberg Supporting layer for a semi-permeable membrane and method for making it
EP0199901A3 (en) * 1985-03-29 1989-08-16 Firma Carl Freudenberg Supporting layer for a semi-permeable membrane and method for making it
WO2009024396A1 (en) * 2007-08-22 2009-02-26 Eswegee Vliesstoff Gmbh Base non-woven fibre for trilaminates
WO2009024393A1 (en) * 2007-08-22 2009-02-26 Eswegee Vliesstoff Gmbh Method for producing a base non-woven fibre as support for a coating
US9437348B2 (en) 2010-12-17 2016-09-06 3M Innovative Properties Company Electrical insulation material
WO2013187956A1 (en) * 2012-06-15 2013-12-19 3M Innovative Properties Company Electrical insulation material
US9754701B2 (en) 2012-06-15 2017-09-05 3M Innovative Properties Company Electrical insulation material
EP3088581B1 (en) 2013-12-27 2020-02-26 Nihon Tokushu Toryo Co., Ltd. Felt, soundproofing material and method for producing soundproofing material

Also Published As

Publication number Publication date
EP0122967A3 (en) 1987-02-04
DE3314691C1 (en) 1984-10-25
EP0122967B1 (en) 1989-07-12
DE3380179D1 (en) 1989-08-17

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