GB2205275A - Composite materials - Google Patents

Composite materials Download PDF

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Publication number
GB2205275A
GB2205275A GB08124421A GB8124421A GB2205275A GB 2205275 A GB2205275 A GB 2205275A GB 08124421 A GB08124421 A GB 08124421A GB 8124421 A GB8124421 A GB 8124421A GB 2205275 A GB2205275 A GB 2205275A
Authority
GB
United Kingdom
Prior art keywords
layer
resin
composite material
layers
conductive
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.)
Granted
Application number
GB08124421A
Other versions
GB2205275B (en
Inventor
William George Howell
Bernard Vincent Wickenden
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Plessey Co Ltd
Original Assignee
Plessey Co Ltd
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 Plessey Co Ltd filed Critical Plessey Co Ltd
Priority to GB8124421A priority Critical patent/GB2205275B/en
Publication of GB2205275A publication Critical patent/GB2205275A/en
Application granted granted Critical
Publication of GB2205275B publication Critical patent/GB2205275B/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
    • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
    • B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
    • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
    • B32B5/28—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer impregnated with or embedded in a plastic substance
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B32B5/024—Woven fabric
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
    • B32B2260/02—Composition of the impregnated, bonded or embedded layer
    • B32B2260/021—Fibrous or filamentary layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
    • B32B2260/04—Impregnation, embedding, or binder material
    • B32B2260/046—Synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/10—Inorganic fibres
    • B32B2262/106—Carbon fibres, e.g. graphite fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
    • B32B2307/202—Conductive

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Laminated Bodies (AREA)

Abstract

A composite material which is radiation absorbing and has a high degree of strength comprises a plurality of layers of material bonded together, at least one of the layers comprising a fibrous material. The layer forming one face of the material is highly electrically conductive and may comprise metal sheet or carbon fibres. At least one subsequent layer has a lower conductivity. The layer forming the opposite face of the material has a substantially zero conductivity and a low permittivity and may comprise aramid fibres. A layer of syntactic foam may be included to increase the strength of the material. The aforesaid subsequent layers may comprise polymer fibres bonded with resin which includes conductive material, (e.g. carbon, iron) in decreasing amounts.

Description

COMPOSITE MATERIALS.
This invention relates to composite materials and more particularly to radiation absorbing materials which have a high degree of inherent strength.
According to the present invention a composite material includes a plurality of layers of material bonded together, at least one of the layers comprising a fibrous material, one layer being located on one face of the composite material and being highly electrically conductive, at least one subsequent layer having a lower conductivity and a layer located on the opposite face of the composite material having a substantially zero conductivity and a low permittivity.
The highly electrically conductive layer may comprise woven carbon fibres, a multidirectional array of carbon fibres or a metallic sheet.
The bonding means may comprise a thermosetting resin and the resin bonding the highly conductive layer preferably includes a conductive material such as carbon or iron.
There may be several subsequent layers, each layer having a lower conductivity. The subsequent layers may comprise polymer fibres bonded with resin which includes conductive material in amounts which decrease with each subsequent layer.
The substantially zero conductivity layer preferably comprises aramid fibres bonded with resin with no conductive material additives.
To increase the strength of the composite material a layer of foam may be included between the subsequent layers and the substantially zero conductivity layer. This foam layer may be reinforced with aramid fibres.
The foam layer may be a polyurethane foam or a syntactic foam which is made up of hollow spheres of glass or plastics or other suitable material embedded in a plastics bonding medium, such as epoxy resin.
Syntactic foam has high strength and is capable of withstanding high hydrostatic pressures and yet gives a reasonably low value of permittivity.
An example of a composite material according to the invention and described by way of example only comprises a first layer of resin bonded woven carbon fibres, the resin being loaded with around 55% of carbon or iron to increase the conductivity of the layer. This layer is approximately 1.4 mm thick.
Thirty six further layers of resin bonded polymer fibres are bonded to this first layer, each layer being slightly less conductive by having reducing quantities of carbon or iron loading in the resin.
Each of these layers is 3mm thick.
A 4mm thick layer of syntactic foam is bonded to these subsequent layers, the foam layer being reinforced with woven aramid fibres. Finally a resin bonded layer of woven aramid fibres is added.
The material is made by conventional laying up techniques, and the resin in each layer may be permitted to cure before the next is added. This method enables articles of quite complex shapes to be made by using suitably shaped moulds.
The material is particularly radiation absorbing, the frequency of the radiation absorbed being dependent upon the thickness of the material.

Claims (8)

WHAT WE CLAIM IS:
1. A composite material including a plurality of layers of material bonded together, at least one of the layers comprising a fibrous material, one layer being located on one face of the composite material and being highly electrically conductive, at least one subsequent layer having a lower conductivity and a layer located on the opposite face of the composite layer having a substantially zero conductivity and a low permittivity.
2. A composite material as claimed in claim 1 in which the highly electrically conductive layer comprises carbon fibres in a woven form or a multidirectional array.
3. A composite material as claimed in claim 1 in which the highly electrically conductive layercomprises a metallic sheet.
4. A composite material as claimed in any of claims 1 to 3 in which the bonding means comprises a thermasetting resin, the resin bonding the highly electrically conductive layer including a conductive material.
5. A composite material as claimed in claim 4 in which the conductive material comprises carbon or iron.
6. A composite material as claimed in any preceding claim comprising several subsequent layers, each layer having a lower conductivity.
7. A composite material as claimed in claim'6 in which the subsequent layers may comprise polymer fibres bonded with resin which includes conductive material in amounts which decrease with each subsequent layer.
8. A composite material constructed and arranged substantially as described hereinbefore.
8. A composite material as claimed in any preceding claim including a syntactic foam layer.
9. A composite material constructed and arranged substantially as hereinbefore described.
Amendments to the claims have been filed as follows CLAIMS:1. A radiation absorbing composite material comprising:a first surface layer of material exhibiting a relatively high electrical conductivity; a second surface layer of material exhibiting both a low substantially zero conductivity and a relativelyZpermittivity; and, bonded between the first and second surface layers, a multilayer structure comprised of a multiplicity of layers of fibrous material impregnated with conductive resin, the conductivity thereof being graded throughout the thickness of the structure from a relatively high value adjacent to the first surface layer to a relatively low value adjacent to the second surface lyaer.
2. A material, as claimed in claim 1, wherein the material of the first surface layer is of metallic sheet.
3. A material, as claimed in claim 1, wherein the material ofthe first surface layer is of carbon fibres, either woven or in multidirectional array , and is impregnated with a resin resin including conductive particulatesteither iron or carbon, the same enhancing the electrical conductivity thereof.
4. A material, as claimed in any one of the preceding claims, wherein each layer of fibrous material is comprised of polymer fibres.
5. A material, as claimed in claim 4, wherein the conductive resin comprises a thermosetting resin material and includes conductive particulates of either carbon Qr iron, the amount of particulate material included in the resin, for each layer, being of progressively decreasing quantity.
6. A material, as claimed in any one of the preceding claims, wherein there is included, between the multilayer structure and the second surface layer, a reinforcement layer of foam material.
7. A material, as claimed in claim 6, wherein the foam material is of syntactic foam.
GB8124421A 1981-08-11 1981-08-11 Composite materials. Expired GB2205275B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8124421A GB2205275B (en) 1981-08-11 1981-08-11 Composite materials.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8124421A GB2205275B (en) 1981-08-11 1981-08-11 Composite materials.

Publications (2)

Publication Number Publication Date
GB2205275A true GB2205275A (en) 1988-12-07
GB2205275B GB2205275B (en) 1989-06-28

Family

ID=10523840

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8124421A Expired GB2205275B (en) 1981-08-11 1981-08-11 Composite materials.

Country Status (1)

Country Link
GB (1) GB2205275B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008056123A1 (en) * 2006-11-06 2008-05-15 Hexcel Composites Limited Improved composite materials
GB2608980A (en) * 1990-08-21 2023-01-18 Colebrand Ltd A protection device

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB812458A (en) * 1956-10-15 1959-04-22 Goodyear Tire & Rubber Improvements relating to laminated conveyor and other belting
GB844140A (en) * 1958-11-10 1960-08-10 Edward Bellamy Mcmillan Electromagnetic-wave-absorbing dielectric wall
GB879489A (en) * 1958-06-24 1961-10-11 Edward Bellamy Mcmillan Absorber for short radio waves
GB1060830A (en) * 1954-05-10 1967-03-08 Eltro Gmbh Improvements in materials with electromagnetic wave reflection properties
GB1074894A (en) * 1956-08-31 1967-07-05 Eltro Gmbh Improvements in or relating to radar camouflage layers
GB1074893A (en) * 1956-08-31 1967-07-05 Eltro Gmbh Radar camouflage for moving objects such as aircraft and ships
GB1074851A (en) * 1959-07-03 1967-07-05 Eltro Gmbh Radar wave absorbing structural material
GB1074895A (en) * 1956-08-31 1967-07-05 Eltro Gmbh Improvements in or relating to radar camouflage nettings
GB1074896A (en) * 1957-01-15 1967-07-05 Eltro Gmbh Non-metallic packing material with interference absorption for electromagnetic waves
GB1074892A (en) * 1956-08-27 1967-07-05 Eltro Gmbh Roofing boards having high frequency electro-magnetic absorbing properties
GB1187503A (en) * 1966-07-11 1970-04-08 Kemi As Improvements in or relating to Stencil Blanks Comprising Stencil Sheets Perforable by Electric Sparks
GB1212216A (en) * 1966-12-22 1970-11-11 Kemi As Stencil blank for electric perforation
GB1258943A (en) * 1968-04-01 1971-12-30
GB1426071A (en) * 1973-01-04 1976-02-25 Electricity Council Roscoe C L Carbon anodes for use in electrode-position cells

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1060830A (en) * 1954-05-10 1967-03-08 Eltro Gmbh Improvements in materials with electromagnetic wave reflection properties
GB1074892A (en) * 1956-08-27 1967-07-05 Eltro Gmbh Roofing boards having high frequency electro-magnetic absorbing properties
GB1074895A (en) * 1956-08-31 1967-07-05 Eltro Gmbh Improvements in or relating to radar camouflage nettings
GB1074894A (en) * 1956-08-31 1967-07-05 Eltro Gmbh Improvements in or relating to radar camouflage layers
GB1074893A (en) * 1956-08-31 1967-07-05 Eltro Gmbh Radar camouflage for moving objects such as aircraft and ships
GB812458A (en) * 1956-10-15 1959-04-22 Goodyear Tire & Rubber Improvements relating to laminated conveyor and other belting
GB1074971A (en) * 1957-01-15 1967-07-05 Eltro Gmbh Non-metallic packing material with interfernce absorption for electromagnetic waves
GB1074896A (en) * 1957-01-15 1967-07-05 Eltro Gmbh Non-metallic packing material with interference absorption for electromagnetic waves
GB879489A (en) * 1958-06-24 1961-10-11 Edward Bellamy Mcmillan Absorber for short radio waves
GB844140A (en) * 1958-11-10 1960-08-10 Edward Bellamy Mcmillan Electromagnetic-wave-absorbing dielectric wall
GB1074851A (en) * 1959-07-03 1967-07-05 Eltro Gmbh Radar wave absorbing structural material
GB1187503A (en) * 1966-07-11 1970-04-08 Kemi As Improvements in or relating to Stencil Blanks Comprising Stencil Sheets Perforable by Electric Sparks
GB1212216A (en) * 1966-12-22 1970-11-11 Kemi As Stencil blank for electric perforation
GB1258943A (en) * 1968-04-01 1971-12-30
GB1426071A (en) * 1973-01-04 1976-02-25 Electricity Council Roscoe C L Carbon anodes for use in electrode-position cells

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2608980A (en) * 1990-08-21 2023-01-18 Colebrand Ltd A protection device
GB2608980B (en) * 1990-08-21 2024-04-10 Colebrand Ltd A protection device
WO2008056123A1 (en) * 2006-11-06 2008-05-15 Hexcel Composites Limited Improved composite materials
EP2371529A3 (en) * 2006-11-06 2013-05-01 Hexcel Composites Limited Improved composite materials

Also Published As

Publication number Publication date
GB2205275B (en) 1989-06-28

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Legal Events

Date Code Title Description
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19950811