Radio frequency wave reducing material and methods for manufacturing same
An improved radio frequency wave attenuating wall (ceiling or floor) or door material comprises a laminated structure having as an integral part thereof one or more layers of a viscoelastic material which also functions as a glue and one or more electrically conducting layers. An electrically conducting material such as tape or a formed metal channel provides an electrical connection between the electrically conducting material and an exposed outer surface of the laminated structure. In one embodiment the electrically conducting material is paint. In one embodiment, standard wallboard, typically gypsum, comprises the external surfaces of the laminated structure and one or more conductive layers are constructed between the gypsum exterior. In one embodiment, the conducting layer material is selected to provide physical security in addition to radio frequency wave attenuation. The construction is such that acoustical attenuation is also achieved.
1. A laminated structure used for constructing RF attenuating walls, floors, or ceilings comprising:
two external layers of a material;
at least one internal electrically conductive constraining layer;
two or more internal layers of a viscoelastic glue separated by said at least one internal electrically conductive constraining layer; and
an electrically conductive tape in electrical contact with said electrically conductive constraining layer and extending out from at least one edge of said structure, said electrically conductive tape being in direct contact with an exposed outer surface of the laminated structure and having an edge laminated between the two external layers of a material.
2. A laminated structure as in claim 1 , wherein the constraining layer comprises metal.
3. A laminated structure as in claim 1 , wherein said two external layers each comprise a selected thickness gypsum board layer.
4. A laminated structure as in claim 3 , wherein said glue comprises a viscoelastic material capable of damping sound.
5. A laminated structure as in claim 4 , wherein said internal constraining layer comprises a sheet metal layer of selected thickness.
6. A laminated structure as in claim 5 , wherein said internal metal layer comprises a sheet metal layer of selected thickness selected to resist physical tampering.
7. A laminated structure as in claim 5 , wherein said sheet metal layer of selected thickness comprises galvanized steel.
8. A laminated structure as in claim 1 , wherein at least one of said two external layers comprises a selected thickness wood layer.
9. A laminated structure as in claim 8 , wherein said glue comprises a viscoelastic material capable of damping sound.
10. A laminated structure as in claim 9 , wherein said internal constraining layer comprises a sheet metal layer of selected thickness.
11. A laminated structure as in claim 10 , wherein said internal metal layer comprises a sheet metal layer of selected thickness selected to resist physical tampering.
12. A laminated structure as in claim 10 , wherein said sheet metal layer of selected thickness comprises galvanized steel.
13. A laminated structure having four edges used for constructing RF attenuating walls, floors, or ceilings comprising:
at least one internal constraining layer of a selected material;
two internal layers of a viscoelastic glue, one such layer on each side of said internal layer;
at least one additional layer of material on the exposed side of each internal layer of viscoelastic glue; and
an external conductive tape which is in electrical contact with the internal constraining layer extending along at least one of said edges and having a portion of said tape extending out from said at least one edge, being in direct contact with an exposed outer surface of the laminated structure and having an edge laminated between the two external layers of a material.
14. A laminated structure as in claim 13 , wherein the constraining layer comprises metal.
15. A laminated structure as in claim 13 , wherein at least one of said two external layers comprises a selected thickness gypsum board layer.
16. A laminated structure as in claim 15 , wherein said glue comprises a viscoelastic material capable of damping sound.
17. A laminated structure as in claim 16 , wherein said internal constraining layer comprises a sheet metal layer of selected thickness.
18. A laminated structure as in claim 17 , wherein said internal metal layer comprises a sheet metal layer of selected thickness selected to resist physical tampering.
19. A laminated structure as in claim 17 , wherein said sheet metal layer of selected thickness comprises galvanized steel.
20. A laminated structure as in claim 13 , wherein at least one of said two external layers comprises a selected thickness wood layer.
21. A laminated structure as in claim 20 , wherein said glue comprises a viscoelastic material capable of damping sound.
22. A laminated structure as in claim 21 , wherein said internal constraining layer comprises a sheet metal layer of selected thickness.
23. A laminated structure as in claim 22 , wherein said internal metal layer comprises a sheet metal layer of selected thickness selected to resist physical tampering.
24. A laminated structure as in claim 22 , wherein said sheet metal layer of selected thickness comprises galvanized steel.
25. A laminated structure used for constructing RF attenuating walls, floors, or ceilings which comprises:
a layer of first electrically conductive material having two surfaces;
a layer of viscoelastic glue on one surface of said layer of first material;
a layer of a second material over said viscoelastic glue; and
an electrically conductive tape attached to said electrically conductive material such that a portion of said electrically conductive tape is in contact with an exposed surface of said structure and having an edge laminated between the layer of first electrically conductive material and the layer of a second material.