GB1579559A - Electrical heating element - Google Patents
Electrical heating element Download PDFInfo
- Publication number
- GB1579559A GB1579559A GB24617/77A GB2461777A GB1579559A GB 1579559 A GB1579559 A GB 1579559A GB 24617/77 A GB24617/77 A GB 24617/77A GB 2461777 A GB2461777 A GB 2461777A GB 1579559 A GB1579559 A GB 1579559A
- Authority
- GB
- United Kingdom
- Prior art keywords
- layer
- conducting
- heating
- composite
- fibre
- 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
- 238000010438 heat treatment Methods 0.000 title claims abstract description 39
- 229920001225 polyester resin Polymers 0.000 claims abstract description 16
- 239000004645 polyester resin Substances 0.000 claims abstract description 16
- 239000003365 glass fiber Substances 0.000 claims abstract description 15
- 239000006229 carbon black Substances 0.000 claims abstract description 13
- 239000000835 fiber Substances 0.000 claims abstract description 8
- 239000002184 metal Substances 0.000 claims abstract description 8
- 229910052751 metal Inorganic materials 0.000 claims abstract description 8
- 239000011888 foil Substances 0.000 claims abstract description 4
- 239000002131 composite material Substances 0.000 claims description 34
- 239000011248 coating agent Substances 0.000 claims description 13
- 238000000576 coating method Methods 0.000 claims description 13
- 239000004071 soot Substances 0.000 claims description 12
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 claims description 10
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 6
- 229920005989 resin Polymers 0.000 claims description 6
- 239000011347 resin Substances 0.000 claims description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 229920006362 Teflon® Polymers 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 239000003822 epoxy resin Substances 0.000 claims description 4
- 239000011521 glass Substances 0.000 claims description 4
- 229920000647 polyepoxide Polymers 0.000 claims description 4
- 229920006337 unsaturated polyester resin Polymers 0.000 claims description 4
- 230000005611 electricity Effects 0.000 claims description 3
- 239000012260 resinous material Substances 0.000 claims description 3
- 229920003002 synthetic resin Polymers 0.000 claims description 3
- 239000000057 synthetic resin Substances 0.000 claims description 3
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 2
- 239000004809 Teflon Substances 0.000 claims description 2
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 2
- 230000002787 reinforcement Effects 0.000 claims description 2
- 239000000126 substance Substances 0.000 claims description 2
- 239000000203 mixture Substances 0.000 abstract 1
- 229920001971 elastomer Polymers 0.000 description 4
- 239000005060 rubber Substances 0.000 description 4
- 239000002322 conducting polymer Substances 0.000 description 3
- 229920001940 conductive polymer Polymers 0.000 description 3
- 239000006239 Easy Processing Channel Substances 0.000 description 1
- 229920002367 Polyisobutene Polymers 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
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—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
- H05B3/12—Heating 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—Heating 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
Landscapes
- Resistance Heating (AREA)
- Surface Heating Bodies (AREA)
- Floor Finish (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Laminated Bodies (AREA)
Abstract
The heating element, intended in particular for the heating of large heating areas, has an inner, electrically conducting layer (2), containing electrodes (3), and outer, electrically non-conducting layers (1). To achieve a greater stability of the characteristic electrical values and a high mechanical strength of the heating element, the electrodes (3) are arranged in the electrically conducting layer (2), which consists at least of a polyester resin composition containing at most 10% by weight of carbon black, referred to the amount of polyester resin, in the form of a metal network or carbon-fibre network or of a perforated metal foil in the same form as the heating element. The electrically conducting layer (2) and the insulating layers (1) are reinforced with glass fibres (4). <IMAGE>
Description
(54) AN IMPROVED ELECTRICAL HEATING ELEMENT
(71) We, POLITECHNIKA GDANSKA, a
Polish State Enterprise of 11/12 Majakowskiego Str, Gdansk-Wreszcz, Poland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to composite electrical heating sheets, and is especially but not exclusively concerned with those of large area.
Low temperature electrical heating sheets heretofore known are described in the following literature:
(1) W.E. Gul, L.N. Carskij, N.S. Majzel,
L.Z. Szenfil, W.S. Zurawlew, N.E. Szczibrja,
Elektroprowodiaszczyje polimernyje materialy Moskwa 1968, pages 204233.
(2) N.H. Norman, Conductive rubbers and plastics, EPC Ltd., Amsterdam-London
New York 1970 pages 248-252.
These known sheets consist of an internal current-conducting layer with embedded or pressed-in electrodes in the form of suitable wires or bands and external layers made of non-conducting polymer. The conducting layer is made of a rubber filled with acetylene soot (70 up to 100 parts by weight of soot per hundred parts of rubber) or of a system consisting of polythene or polyisobutylene and acetylene soot or of polypropylene and acetylene soot (the content of acetylene soot in these systems being equal to approx. 100 parts by weight per hundred parts of polymer).
A considerable drawback of the described sheets is instability of the electrical parameters, particularly in the case of the use of conducting rubbers, as well as low durability of the electrode-conducting polymer contacts.
The considerable content of soot in the conducting polymers causes in effect visible worsening of mechanical properties of the sheets produced.
According to the present invention we provide a composite electrical heating sheet comprising (a) an electrically-conducting core sheet which includes a conducting layer containing in admixture a polyester resin and carbon black and a pair of spaced superposed conducting layers of openwork material respectively connectible to a source of electricity to form electrodes so that current flows through the conducting layer from a face of one electrode to the opposed face of the other electrode, and (b) electrically insulating coating sheets on the faces of the core sheet.
Preferably each layer of openwork material is selected from a metal grid, a carbon-fibre grid, and perforated metal foil.
Preferably also not more than 10% by weight of the carbon black is mixed with the polyester resin to form the conducting layer.
Preferably also the conducting core sheet comprises superposed layers in the following sequence: a conducting layer, a first openwork layer, an intermediate layer of electrically conducting synthetic resin, and a second openwork layer.
By providing electrodes in the form of spaced, superposed openwork layers substantially co-extensive with the other layers of the sheet, the electric current passes in a direction from face to face of the composite sheet instead of in the usual direction from edge to edge of the composite sheet. This arrangement has the following advantages:
(a) the electrodes bond firmly to the other conducting layer or layers of the conducting core sheet, and so there is prevented peeling of the electrodes from the other conducting layer(s),
(b) large-area composite heating sheets can be produced,
(c) the composite heating sheets can readily be produced in a variety of shapes, and
(d) low voltage can be applied-thus composite sheets of up to 5 mm thick supplied with 24 V are heated to a temperature of 70"C.
The coating sheets are preferably of synthetic resinous material.
The external insulating coating sheets can be coloured.
Owing to their conducting characteristic, the composite heating sheets are safe from the point of view of fire protection, and after the addition of suitable self-extinguishing substances, they are completely incombustible.
The heating sheets according to the invention may be used as heaters for the heating of rooms in public buildings, flats and bungalows. The low temperature of the heating sheets, which does not exceed 120 degrees
Centigrade, eliminates the danger of fire and burning. Owing to a practically free choice of shape, the heating sheets thus produced may be used for heating of transport such as tramways and trains, and particularly ships and small vessels.
The described heating sheets are also suitable for use in heating highways and pavements, and railway switches and junctions as well as in heating stadiums (e.g.
football fields and tennis courts).
The invention is illustrated by the following
Examples:
Example 1
On a glass plate covered with a separating agent in the form of a polyvinyl alcohol there is laid an insulating layer made of polyester resin and of 0 3 mm thickness and, when gelled, this layer is covered with an insulating layer consisting of a glass fibre mat impregnated with polyester resin. The insulating coating sheet thus obtained is coated with a paste which forms a conducting layer, this paste being obtained by mixing an unsaturated polyester resin with 2 weight per cent of carbon black in the form of acetylene soot.On this layer a first electrode is laid, the electrode being a layer of copper in the form of a grid or mesh, and thereupon four glass-fibre mats soaked with a conducting polyester resin and a second electrode also being a layer of copper in the form of a grid or mesh are laid, the latter layer being coated with a layer of conducting resin. When this composite has gelled, the whole sandwich is coated with a glass-fibre mat soaked with insulating polyester resin.
The heating sheet thus produced is, upon hardening, separated from the glass plate.
Example 2
On a Teflon (Trade Mark) plate there is laid an insulating layer 0 5 mm thick made of epoxy resin. This layer is coated with a conducting layer of a paste obtained by mixing-in unsaturated polyester resin with 6 per cent by weight of carbon black in the form of acetylene soot, and upon the sandwich thus obtained are laid in a due order the following layers: a first electrode which is a layer of carbon fibre in the form of a grid or mesh, two layers in the form of mats of glass fibre impregnated with a conducting resin, and a second electrode which is a layer of carbon fibre in the form of a grid or mesh. When the composite has gelled, it is coated with an insulating layer of epoxy resin. The electrodes are combined with leads, and the composite heating sheet so formed is separated from the
Teflon plate.
In each of the foregoing Examples the heating sheet is thus a combination of (a) a conducting core sheet composed of resin layers and a pair of spaced superposed electrode layers and (b) a pair of insulating coating sheets on the core sheet.
WHAT WE CLAIM IS:
1. A composite electrical heating sheet comprising (a) an electrically-conducting core sheet which includes a conducting layer containing in admixture a polyester resin and carbon black and a pair of spaced superposed conducting layers of openwork material respectively connectible to a source of electricity to form electrodes so that current flows through the conducting layer from a face of one electrode to the opposed face of the other electrode, and (b) electrically insulating coating sheets on the faces of the core sheet.
2. A composite sheet according to claim 1, wherein each layer of openwork material is selected from a metal grid, a carbon-fibre grid, and perforated metal foil.
3. A composite sheet according to claim 1 or 2, wherein not more than 10% by weight of the carbon black is mixed with the polyester resin to form the conducting layer.
4. A composite sheet according to any one of claims 1 to 3, wherein the conducting layer includes glass-fibre reinforcement.
5. A composite sheet according to any one of claims 1 to 4, wherein the coating sheets are of synthetic resinous material.
6. A composite sheet according to claim 5, wherein the coating sheets are glass-fibre reinforced.
7. A composite sheet according to any one of claims 1 to 6, wherein the conducting core sheet comprises superposed layers in the following sequence: a conducting layer, a first openwork layer, an intermediate layer of electrically-conducting synthetic resin, and a second openwork layer.
8. A composite sheet according to claim 7, wherein the intermediate layer is glass-fibre reinforced.
9. A composite sheet according to any one of the preceding claims, wherein the carbon black is in the form of acetylene soot.
10. A composite electrical heating sheet, substantially as hereinbefore described with reference to Example 1 or Example 2.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (10)
1. A composite electrical heating sheet comprising (a) an electrically-conducting core sheet which includes a conducting layer containing in admixture a polyester resin and carbon black and a pair of spaced superposed conducting layers of openwork material respectively connectible to a source of electricity to form electrodes so that current flows through the conducting layer from a face of one electrode to the opposed face of the other electrode, and (b) electrically insulating coating sheets on the faces of the core sheet.
2. A composite sheet according to claim 1, wherein each layer of openwork material is selected from a metal grid, a carbon-fibre grid, and perforated metal foil.
3. A composite sheet according to claim 1 or 2, wherein not more than 10% by weight of the carbon black is mixed with the polyester resin to form the conducting layer.
4. A composite sheet according to any one of claims 1 to 3, wherein the conducting layer includes glass-fibre reinforcement.
5. A composite sheet according to any one of claims 1 to 4, wherein the coating sheets are of synthetic resinous material.
6. A composite sheet according to claim 5, wherein the coating sheets are glass-fibre reinforced.
7. A composite sheet according to any one of claims 1 to 6, wherein the conducting core sheet comprises superposed layers in the following sequence: a conducting layer, a first openwork layer, an intermediate layer of electrically-conducting synthetic resin, and a second openwork layer.
8. A composite sheet according to claim 7, wherein the intermediate layer is glass-fibre reinforced.
9. A composite sheet according to any one of the preceding claims, wherein the carbon black is in the form of acetylene soot.
10. A composite electrical heating sheet, substantially as hereinbefore described with reference to Example 1 or Example 2.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PL1976190548A PL112920B1 (en) | 1976-06-18 | 1976-06-18 | Heating element,particularly large surface one |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1579559A true GB1579559A (en) | 1980-11-19 |
Family
ID=19977380
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB24617/77A Expired GB1579559A (en) | 1976-06-18 | 1977-06-13 | Electrical heating element |
Country Status (16)
| Country | Link |
|---|---|
| JP (1) | JPS52156436A (en) |
| AT (1) | AT374650B (en) |
| CA (1) | CA1091739A (en) |
| CH (1) | CH616800A5 (en) |
| CS (1) | CS198258B2 (en) |
| DD (1) | DD131060A5 (en) |
| DE (1) | DE2726791A1 (en) |
| FR (1) | FR2355427A1 (en) |
| GB (1) | GB1579559A (en) |
| HU (1) | HU175149B (en) |
| IT (1) | IT1083386B (en) |
| NO (1) | NO772121L (en) |
| PL (1) | PL112920B1 (en) |
| RO (1) | RO73410A (en) |
| SE (1) | SE7706995L (en) |
| YU (1) | YU139777A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2182413A (en) * | 1985-11-04 | 1987-05-13 | Lee Fisher Robinson | Protecting pipelines and tanks |
| EP2799477A3 (en) * | 2013-05-03 | 2015-03-04 | Rolls-Royce plc | Composite structure |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4314230A (en) * | 1980-07-31 | 1982-02-02 | Raychem Corporation | Devices comprising conductive polymers |
| JPS61203588A (en) * | 1985-03-06 | 1986-09-09 | 日本ユニカーボン株式会社 | Carbon heat generating body |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS529595Y2 (en) * | 1971-06-23 | 1977-02-28 | ||
| JPS516369A (en) * | 1974-07-05 | 1976-01-19 | Hitachi Ltd |
-
1976
- 1976-06-18 PL PL1976190548A patent/PL112920B1/en unknown
-
1977
- 1977-06-03 CH CH685077A patent/CH616800A5/en not_active IP Right Cessation
- 1977-06-06 YU YU01397/77A patent/YU139777A/en unknown
- 1977-06-08 AT AT0406277A patent/AT374650B/en not_active IP Right Cessation
- 1977-06-08 FR FR7717549A patent/FR2355427A1/en active Granted
- 1977-06-13 GB GB24617/77A patent/GB1579559A/en not_active Expired
- 1977-06-14 DE DE19772726791 patent/DE2726791A1/en active Pending
- 1977-06-15 CA CA280,592A patent/CA1091739A/en not_active Expired
- 1977-06-16 HU HU77PO651A patent/HU175149B/en unknown
- 1977-06-16 SE SE7706995A patent/SE7706995L/en unknown
- 1977-06-16 RO RO7790726A patent/RO73410A/en unknown
- 1977-06-16 DD DD7700199530A patent/DD131060A5/en unknown
- 1977-06-16 NO NO772121A patent/NO772121L/en unknown
- 1977-06-17 CS CS774032A patent/CS198258B2/en unknown
- 1977-06-17 JP JP7119377A patent/JPS52156436A/en active Pending
- 1977-06-17 IT IT68414/77A patent/IT1083386B/en active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2182413A (en) * | 1985-11-04 | 1987-05-13 | Lee Fisher Robinson | Protecting pipelines and tanks |
| GB2182413B (en) * | 1985-11-04 | 1989-12-06 | Lee Fisher Robinson | Improvements relating to protection of pipelines and fluid containers |
| EP2799477A3 (en) * | 2013-05-03 | 2015-03-04 | Rolls-Royce plc | Composite structure |
| US10356894B2 (en) | 2013-05-03 | 2019-07-16 | Rolls-Royce Plc | Composite structure |
Also Published As
| Publication number | Publication date |
|---|---|
| CA1091739A (en) | 1980-12-16 |
| SE7706995L (en) | 1977-12-19 |
| RO73410A (en) | 1981-09-24 |
| CS198258B2 (en) | 1980-05-30 |
| FR2355427B1 (en) | 1982-01-15 |
| AT374650B (en) | 1984-05-10 |
| IT1083386B (en) | 1985-05-21 |
| YU139777A (en) | 1982-05-31 |
| DE2726791A1 (en) | 1977-12-22 |
| CH616800A5 (en) | 1980-04-15 |
| FR2355427A1 (en) | 1978-01-13 |
| PL112920B1 (en) | 1980-11-29 |
| HU175149B (en) | 1980-05-28 |
| DD131060A5 (en) | 1978-05-24 |
| ATA406277A (en) | 1983-09-15 |
| JPS52156436A (en) | 1977-12-26 |
| NO772121L (en) | 1977-12-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |