Electromagnetic shield

• US 4,539,433 A
• Filed: 09/07/1983
• Issued: 09/03/1985
• Est. Priority Date: 11/24/1982
• Status: Expired due to Term

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Hashimoto, Yasuo, Narumiya, Yoshikazu, Ishino, Ken
• Primary Examiner(s): Grimley, A. T.
• Assistant Examiner(s): NIMMO, MORRIS
• Application Number:
  US06/529,991
• Time in Patent Office: 727 Days
• Field of Search: 174/35 MS, 174/35 GC, 174/36, 219/10.55 D, 333/243, 87/7, 87/9, 343/18 A
• US Class Current: 174/391
• CPC Class Codes: G21F 9/06 Processing separating different isotopes of the same chemical element B01D59/00
• CPC Class Codes: H05K 9/009 comprising electro-conductive fibres, e.g. metal fibres, carbon fibres, metallised textile fibres, electro-conductive mesh, woven, non-woven mat, fleece, cross-linked

Abstract

An electromagnetic shielding material for absorbing electromagnetic energy has been found. The shielding material is flexible and has a thin conductive core with a composite ferrite material deposited around the core. The composite ferrite material is a mixture of ferrite powder and a binder for binding the powder. The conductive core may be formed in the shape of a flat sheet or an elongated textile shape. The binder may be a high molecular compound like plastic. When the core is in a textile shape, the textile covered with the composite ferrite material is woven into a cloth which is sufficiently flexible to form around any desired shape.

Claims

1. A cloth electromagnetic shield, said shield comprising:

a flexible textile member which is substantially electrically conductive;

a ferrite layer deposited around said textile member, said ferrite layer being a mixture of ferrite powder and a binder for binding said ferrite powder so that the volume ratio of said ferrite powder to the mixture is in the range of 0.2 to 0.8, wherein said cloth is woven from said textile member.

2. An electromagnetic shield according to claim 1, wherein said textile member is formed of carbon textile dispersed with copper ions.

4. An electromagnetic shield according to claim 1, wherein the thickness of said textile member with said ferrite layer is in the range between 3 mm and 5 mm.

5. An electromagnetic shield according to claim 2, wherein the thickness of said textile member with said ferrite layer is larger than twice the thickness of said textile member.

7. An electromagnetic shield according to claim 1, wherein said ferrite layer is N_i -Z_n group ferrite.

8. An electromagnetic shield according to claim 1, wherein said textile member is formed from carbon textile.

9. An electromagentic shield according to claim 1, wherein said textile member is formed from the mixed spinning of conductive textile and dielectric textile.

10. An electromagnetic shield according to claim 1, wherein said textile member is formed of acrylic resin dispersed with copper ions.

3. An electromagnetic shield according to claim 3, wherein said textile member is elongated and circular in construction.

6. An electromagnetic shield according to claim 3, wherein the diameter of said textile member with said ferrite layer is larger than twice the diameter of said textile member.