WO1987003158A1 - Electric resistance sheet and method of producing such - Google Patents

Electric resistance sheet and method of producing such Download PDF

Info

Publication number
WO1987003158A1
WO1987003158A1 PCT/FI1986/000127 FI8600127W WO8703158A1 WO 1987003158 A1 WO1987003158 A1 WO 1987003158A1 FI 8600127 W FI8600127 W FI 8600127W WO 8703158 A1 WO8703158 A1 WO 8703158A1
Authority
WO
WIPO (PCT)
Prior art keywords
sheet
electric resistance
plastics
resistance sheet
woven
Prior art date
Application number
PCT/FI1986/000127
Other languages
French (fr)
Inventor
Eino Laine
Göran NYSTEDT
Kay RÖKMAN
Original Assignee
A. Ahlstrom Corporation
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by A. Ahlstrom Corporation filed Critical A. Ahlstrom Corporation
Publication of WO1987003158A1 publication Critical patent/WO1987003158A1/en
Priority to NO872937A priority Critical patent/NO872937D0/en

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/10—Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor
    • H05B3/12—Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
    • H05B3/14—Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
    • H05B3/146—Conductive polymers, e.g. polyethylene, thermoplastics

Definitions

  • the invention relates to an electric resistance sheet and a method of producing such.
  • a method of producing an electric resistance sheet characterized in that the fibers of a. non-woven or woven fabric of carbon fibers are bonded together by plastics containing thermoplas ⁇ tics, whereby a mouldable sheet or object that can be heated electrically is produced.
  • an electric resistance sheet characterized in that it contains a layer of a non-woven or woven fabric of carbon fibers which are bonded together by plastics a substantial portion of which being thermoplastic so as to be mouldable.
  • the present invention is based upon the mouldability characte ⁇ ristics of a carbon fiber fabric when the fabric forms a part of a thermoplastic sheet.
  • Thermoplastics is added as a liquid or a powder either before or after formation of a carbon fiber web or on a finished non-woven mat, whereby a uniform plastic sheet is attained.
  • the sheet can contain other layers of other non-woven fiber mats or even loosely woven fiber fabrics.
  • Metal strips for electric input or other suitable conductors or electrodes that are known per se for this purpose are connected to the edges of the carbon fiber mat or otherwise spaced apart thereon.
  • a sheet of this type can be formed by reheating it in a mould either under pressure or without pressure and the sheet can be heated with a varying direct-current.
  • a product thus produced may be varied considerably in shape and such shape can signi ⁇ ficantly differ from that of the original. If the product is used in furniture the relevant national standards have to be observed. Rules and statutes naturally regulate the electrical connections of the product.
  • the invention is particularly economically superior when compared with other known mouldable heating elements.
  • a vowen carbon fiber fabric can be used in stead of a non-woven fabric but the end product will not be as mouldable nor as economic. Carbon fiber can act, besides as a heating element, as a most preferable filler since it adds to the strength, it is light and does not contain metal that adds
  • Fig. 1 is a schematic front elevation of a sheet element or device suitable to be used as a wall element that can be heated and which forms one embodiment of the invention
  • Fig. 2 is a cross-section through the sheet device of Fig. 1;
  • Fig. 3 is a schematic perspective illustration of a portion of a heatable mould formed of a sheet device forming a second embodiment of the invention.
  • Figs. 1 and 2 illustrate an elastic or resilient element embodiment forming a first example of a wall element that can be heated or warmed-up.
  • a carbon fiber felt 1 in which the fibers are bonded by a binder containing 90 % thermoplastics, such as aerylate latex and 10 % thermosetting plastics, such as melamine resin, is coated with PVC or with some other film-forming polymer 2.
  • Electrodes 3, for instance adhesive copper tape, are connected to the ends or edges of elements; the side against a wall is coated with mechanically formed or chemical foam, such as PVC or some other polymer, to form an insulation layer 4.
  • the element commences warming-up when direct-current or alternating-currect is being conducted therethrough at a suitable voltage - which is dependent on the resistance of the carbon fiber felt.
  • the sheet devices are formed as hard, platelike elements which comprise a second example of a wall element that can be heated.
  • the elements comprised of a carbon fiber felt and thermoplastics (not illustrated) are fitted in a mould; wall elements of different sizes and thickness are achieved by different compression and heat is generated between the element ends or edges by means of electric current.
  • a typical heating capacity value is 0,1 - 1 kW/ depending on the surface temperature and the polymer.
  • Fig. 3 is a fragmentary schematic perspective illustration of a mould used in the manufacture of boats and comprises one example of a mould that can be warmed-up utilizing the present invention.
  • reinforced plastics is used in the manu ⁇ facture, of boats (and other formed pieces) and a portion of a mould for use in such construction is illustrated in Fig. 3.
  • a carbon fiber felt 6 having a grammage of ca. 20-30 g/m and containing a binder insoluble in styrene is laminated on a boat mould 5 near the surface.
  • Adhesive copper tapes 7 are disposed at suitable distances for the supply of direct- current from a welding transformer (not shown) .
  • FeConst wires are also disposed in the laminate for temperature controls. The temperature is regulated directly from the transformer. Curing time can be shortened and curing quality improved.
  • The- temperature of the mould can be kept constant even if the temperature of the building varies.
  • the mould temperatures can easily be regulated and adjusted by means of a microprocessor.
  • the fabric of carbon fibers can have a grammage of
  • the rate of plastic binder is 10 - 25 % by weight. Preferably at least 50 % and more preferably
  • thermoplastics 80 - 100 %, of the binder consists of thermoplastics.

Abstract

A method of producing a mouldable fiber reinforced plastic sheet in which at least one of the reinforcing fiber layers is a woven or non-woven fabric of carbon fibers, that can be used as a heating element. The carbon fibers are bonded together by plastics which contain thermoplastics. Upon application of electric current the sheet warms quickly and evenly and a suitable voltage is 0,1 - 380 V. The current strength and the voltage can vary.

Description

ELECTRIC RESISTANCE SHEET AND METHOD OF PRODUCING SUCH
Technical field;
The invention relates to an electric resistance sheet and a method of producing such.
Background Art:
It is well known to produce large surfaced means that can be heated, for heating, for instance a cealing or a floor. A traditional resistance material has been metal but the elastic or resilient qualities thereof are not very good. It is also well known to place heating resistances in shutterings in order- to allow casting especially during a cold period. Is has, however, been a problem to provide a heating sheet or a heatable mould that would be readily mouldable.
Disclosure of Invention:
According to the present invention there is provided a method of producing an electric resistance sheet, characterized in that the fibers of a. non-woven or woven fabric of carbon fibers are bonded together by plastics containing thermoplas¬ tics, whereby a mouldable sheet or object that can be heated electrically is produced.
Also according to the oresent invention there is provided an electric resistance sheet, characterized in that it contains a layer of a non-woven or woven fabric of carbon fibers which are bonded together by plastics a substantial portion of which being thermoplastic so as to be mouldable.
The present invention is based upon the mouldability characte¬ ristics of a carbon fiber fabric when the fabric forms a part of a thermoplastic sheet. Thermoplastics is added as a liquid or a powder either before or after formation of a carbon fiber web or on a finished non-woven mat, whereby a uniform plastic sheet is attained. In addition to the carbon fiber mat, the sheet can contain other layers of other non-woven fiber mats or even loosely woven fiber fabrics. Metal strips for electric input or other suitable conductors or electrodes that are known per se for this purpose are connected to the edges of the carbon fiber mat or otherwise spaced apart thereon. A sheet of this type can be formed by reheating it in a mould either under pressure or without pressure and the sheet can be heated with a varying direct-current. A product thus produced may be varied considerably in shape and such shape can signi¬ ficantly differ from that of the original. If the product is used in furniture the relevant national standards have to be observed. Rules and statutes naturally regulate the electrical connections of the product. The invention is particularly economically superior when compared with other known mouldable heating elements. A vowen carbon fiber fabric can be used in stead of a non-woven fabric but the end product will not be as mouldable nor as economic. Carbon fiber can act, besides as a heating element, as a most preferable filler since it adds to the strength, it is light and does not contain metal that adds
2 to radar reflections. Heating capacities of 24 k /m have been reached by test specimens.
Best Mode for Carrying Out the Invention:
The invention will be described further, by way of example, with reference to the accompanying drawings, in which:
Fig. 1 is a schematic front elevation of a sheet element or device suitable to be used as a wall element that can be heated and which forms one embodiment of the invention; Fig. 2 is a cross-section through the sheet device of Fig. 1;
Fig. 3 is a schematic perspective illustration of a portion of a heatable mould formed of a sheet device forming a second embodiment of the invention.
Figs. 1 and 2 illustrate an elastic or resilient element embodiment forming a first example of a wall element that can be heated or warmed-up. A carbon fiber felt 1, in which the fibers are bonded by a binder containing 90 % thermoplastics, such as aerylate latex and 10 % thermosetting plastics, such as melamine resin, is coated with PVC or with some other film-forming polymer 2. Electrodes 3, for instance adhesive copper tape, are connected to the ends or edges of elements; the side against a wall is coated with mechanically formed or chemical foam, such as PVC or some other polymer, to form an insulation layer 4.
The element commences warming-up when direct-current or alternating-currect is being conducted therethrough at a suitable voltage - which is dependent on the resistance of the carbon fiber felt.
In an alternative embodiment the sheet devices are formed as hard, platelike elements which comprise a second example of a wall element that can be heated. The elements comprised of a carbon fiber felt and thermoplastics (not illustrated) are fitted in a mould; wall elements of different sizes and thickness are achieved by different compression and heat is generated between the element ends or edges by means of electric current.
An advantage of these hard elements is that they make it possible to produce large surfaces having different shapes and whereby the surface temperature of, for example, floors and walls can be kept low so that the heat generated may feel
2 agreeable. A typical heating capacity value is 0,1 - 1 kW/ depending on the surface temperature and the polymer.
Fig. 3 is a fragmentary schematic perspective illustration of a mould used in the manufacture of boats and comprises one example of a mould that can be warmed-up utilizing the present invention.
Many curing plastics require heat in order to cure and to improve their strength.
As is well known, reinforced plastics is used in the manu¬ facture, of boats (and other formed pieces) and a portion of a mould for use in such construction is illustrated in Fig. 3.
2 A carbon fiber felt 6 having a grammage of ca. 20-30 g/m and containing a binder insoluble in styrene is laminated on a boat mould 5 near the surface. Adhesive copper tapes 7 are disposed at suitable distances for the supply of direct- current from a welding transformer (not shown) . FeConst wires are also disposed in the laminate for temperature controls. The temperature is regulated directly from the transformer. Curing time can be shortened and curing quality improved. The- temperature of the mould can be kept constant even if the temperature of the building varies. The mould temperatures can easily be regulated and adjusted by means of a microprocessor.
The fabric of carbon fibers can have a grammage of
2 5 - 50 g/m . The rate of plastic binder is 10 - 25 % by weight. Preferably at least 50 % and more preferably
80 - 100 %, of the binder consists of thermoplastics. Industrial Applicability:
The invention is not intended to be limited to the above embodiments but it can be modified and applied in various ways whilst remaining within the inventive concept as defined by the apendent claims.

Claims

1. A method of producing an electric resistance sheet, c h a - r a c t e r i z e d in that the fibers of a non-woven or woven fabric of carbon fibers are bonded together by plastics containing thermoplastics, whereby a mouldable sheet or object that can be heated electrically is accomplished.
2. A method as claimed in claim 1, c h a r a c t e r i z e d in that a non-woven mat of carbon fibers is used as a heating element in a mould for objects of glass fiber reinforced resins or plastics.
3. An electric resistance sheet, c h a r a c t e r i z e d in that it contains a layer of a non-woven or woven fabric of carbon fibers which are bonded together by plastics a substan¬ tial portion of which being thermoplastic so as to be mouldable.
4. An electric resistance sheet as claimed in claim 3, c h a¬ r a c t e r i z e d in that the fabric contains 75 - 90 % carbon fibers and 10 - 25 % plastics binder.
5. An electric resistance sheet as claimed in claim 3, c h a ¬ r a c t e r i z e d in that plastics that contain thermo¬ plastics, at least 50 % are used as a binder.
6. An electric resistance sheet as claimed in claim 4 or 5, c h a r a c t e r i z e d in that the binder contains about 80 - 100 % thermoplastics and 0 - 20 % thermosetting plastics.
7. An electric resistance sheet as claimed in any of claims 3 to 6 in combination' with a mould for objects to be formed of glass fiber reinforced resins or plastics, c h a r a c ¬ t e r i z e d in that it contains a heating element of the mould.
8. An electric resistance sheet as claimed in any of claims
3 to 7, c h a r a c t e r i z e d in that spaced apart electric conductors are applied to the sheet to permit current to be applied to heat the sheet.
9. An electric resistance sheet as claimed in any of claims 3 to 6, c h a r a c t e r i z e d in that the bonded sheet is coated with PVC or other film-forming polymer, that electrical conductors, such as copper tape are connected to the edges of the sheet, and that one surface of the sheet has a thermally insulating layer applied thereto.
10. An electric resistance sheet as claimed in claim 9, c h a r a c t e r i z e d in that the sheet-like material is hard as a result of being compressed prior to heating thereof.
PCT/FI1986/000127 1985-11-14 1986-11-04 Electric resistance sheet and method of producing such WO1987003158A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
NO872937A NO872937D0 (en) 1985-11-14 1987-07-14 ELECTRICAL RESISTANCE SHEET AND PROCEDURE FOR PREPARING SUCH.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI854477 1985-11-14
FI854477A FI81709C (en) 1985-11-14 1985-11-14 FOERFARANDE FOER FRAMSTAELLNING AV EN MOTSTAONDSKIVA AV PLAST OCH MOTSTAONDSSKIVA.

Publications (1)

Publication Number Publication Date
WO1987003158A1 true WO1987003158A1 (en) 1987-05-21

Family

ID=8521680

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1986/000127 WO1987003158A1 (en) 1985-11-14 1986-11-04 Electric resistance sheet and method of producing such

Country Status (3)

Country Link
JP (1) JPS63503417A (en)
FI (1) FI81709C (en)
WO (1) WO1987003158A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2285729A (en) * 1993-12-24 1995-07-19 British Tech Group Int Improvements relating to electrically conductive materials
FR2736500A1 (en) * 1995-07-03 1997-01-10 Gouthez Philippe Electric heating element in thermoplastic support - has conductive mesh set in thermoplastic matrix that supports and provides insulation
WO2001054874A1 (en) * 2000-01-29 2001-08-02 Wolf Gmbh Feuerfeste Produkte Absorbent gypsum form for the production of ceramic bodies from slurry and the production of ceramic bodies from slurry by use of the absorbent gypsum form
GB2421952A (en) * 2005-01-07 2006-07-12 Univ Sheffield Fibre-reinforced polymer composite with damage detection system
GB2453933A (en) * 2007-10-18 2009-04-29 Gkn Aerospace Services Ltd Aircraft leading edge ice protection system comprising a thermoplastic heater mat
EP3691407A4 (en) * 2017-09-27 2021-06-23 Everwelltechnology Co., Ltd Carbon felt heating apparatus and manufacturing method therefor

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1285681A (en) * 1970-01-01 1972-08-16 Short Brothers & Harland Improvements in or relating to load carrying structures
GB1315170A (en) * 1969-11-21 1973-04-26 Kureha Chemical Ind Co Ltd Planar heat generator and production thereof
US3774299A (en) * 1970-09-21 1973-11-27 Kureha Chemical Ind Co Ltd Method for production of panel heater
US3839134A (en) * 1972-02-09 1974-10-01 Kansai Hoon Kogyo Kk Electric heat-generating sheet assembly
EP0022919A2 (en) * 1979-07-13 1981-01-28 Messerschmitt-Bölkow-Blohm Gesellschaft mit beschränkter Haftung Method for the impregnation of tissues by resin injection
DE2303389C2 (en) * 1972-01-24 1985-03-28 Rhône-Poulenc-Textile, Paris Electrically conductive felts with good mechanical properties

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1315170A (en) * 1969-11-21 1973-04-26 Kureha Chemical Ind Co Ltd Planar heat generator and production thereof
GB1285681A (en) * 1970-01-01 1972-08-16 Short Brothers & Harland Improvements in or relating to load carrying structures
US3774299A (en) * 1970-09-21 1973-11-27 Kureha Chemical Ind Co Ltd Method for production of panel heater
DE2303389C2 (en) * 1972-01-24 1985-03-28 Rhône-Poulenc-Textile, Paris Electrically conductive felts with good mechanical properties
US3839134A (en) * 1972-02-09 1974-10-01 Kansai Hoon Kogyo Kk Electric heat-generating sheet assembly
EP0022919A2 (en) * 1979-07-13 1981-01-28 Messerschmitt-Bölkow-Blohm Gesellschaft mit beschränkter Haftung Method for the impregnation of tissues by resin injection

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2285729A (en) * 1993-12-24 1995-07-19 British Tech Group Int Improvements relating to electrically conductive materials
GB2285729B (en) * 1993-12-24 1997-10-22 British Tech Group Int Electrically conductive resistance heater
US6172344B1 (en) 1993-12-24 2001-01-09 Gorix Limited Electrically conductive materials
FR2736500A1 (en) * 1995-07-03 1997-01-10 Gouthez Philippe Electric heating element in thermoplastic support - has conductive mesh set in thermoplastic matrix that supports and provides insulation
WO2001054874A1 (en) * 2000-01-29 2001-08-02 Wolf Gmbh Feuerfeste Produkte Absorbent gypsum form for the production of ceramic bodies from slurry and the production of ceramic bodies from slurry by use of the absorbent gypsum form
GB2421952A (en) * 2005-01-07 2006-07-12 Univ Sheffield Fibre-reinforced polymer composite with damage detection system
GB2421952B (en) * 2005-01-07 2010-04-21 Univ Sheffield Damage Detection System
GB2453933A (en) * 2007-10-18 2009-04-29 Gkn Aerospace Services Ltd Aircraft leading edge ice protection system comprising a thermoplastic heater mat
EP3691407A4 (en) * 2017-09-27 2021-06-23 Everwelltechnology Co., Ltd Carbon felt heating apparatus and manufacturing method therefor

Also Published As

Publication number Publication date
FI854477A0 (en) 1985-11-14
FI81709B (en) 1990-07-31
FI854477A (en) 1987-05-15
FI81709C (en) 1990-11-12
JPS63503417A (en) 1988-12-08

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