Compositions, methods, and devices providing shielding in communications cables

Abstract

Compositions, devices, and methods for providing shielding communications cables are provided. In some embodiments, compositions including electrically conductive elements are disclosed. In other embodiments, cable separators, tapes, and nonwoven materials including various electrically conductive elements are disclosed.

What is claimed: 
     
         1 . A tape for use in a communications cable, comprising:
 a flexible, polymeric sheet extending from a proximal end to a distal end; and   a plurality of electrically conductive inclusions distributed throughout the polymeric sheet;   wherein said polymeric sheet can be curved or bent along its longitudinal axis so as to form a shape suitable for at least partially surrounding one or more conductors.   
     
     
         2 . The tape of  claim 1 , wherein the plurality of electrically conductive inclusions comprises a plurality of metal inclusions. 
     
     
         3 . The tape of  claim 2 , wherein the plurality of metal inclusions comprises any of silver, aluminum, copper, gold, bronze, tin, zinc, iron, nickel, indium, gallium, stainless steel, and a combination thereof. 
     
     
         4 . The tape of  claim 2 , wherein the plurality of metal inclusions exhibits a needle-like shape, a flake-like shape, or a combination thereof. 
     
     
         5 . The tape of  claim 3 , wherein the plurality of electrically conductive inclusions further comprises a plurality of carbon fibers. 
     
     
         6 . The tape of  claim 1 , wherein the polymeric sheet comprises a polyolefin, a fluoropolymer, or a combination thereof. 
     
     
         7 . The tape of  claim 6 , wherein the fluoropolymer comprises a perfluoropolymer. 
     
     
         8 . The tape of  claim 7 , wherein the perfluoropolymer comprises any of FEP, MFA and PFA. 
     
     
         9 . The tape of  claim 1 , wherein the electrically conductive inclusions comprises a volume fraction of the tape in a range of about 1% to about 40%. 
     
     
         10 . The tape of  claim 1 , wherein the electrically conductive inclusions comprises a volume fraction of the tape in a range of about 5% to about 10%. 
     
     
         11 . The tape of  claim 1 , wherein the polymeric sheet is foamed. 
     
     
         12 . The tape of  claim 1 , wherein the tape has a thickness in a range of about 0.001 inches to about 0.02 inches. 
     
     
         13 . The tape of  claim 1 , wherein said tape comprises a plurality of polymeric fibers. 
     
     
         14 . The tape of  claim 1 , wherein said tape exhibits a DC electrical conductivity along an axial direction in a range of about 1×10 3  Siemens/meter to about 3.5×10 7  Siemens/meter. 
     
     
         15 . The tape of  claim 1 , wherein said tape exhibits a sheet resistance in a range of about 1×10 −5  ohms per square to about 1×10 5  ohms per square. 
     
     
         16 . A tape for use in a communications cable, comprising:
 a polymeric substrate layer extending from a proximal end to a distal end; and   a metallic layer dispersed over at least a portion of a surface of the polymeric substrate layer;   wherein said substrate layer and said metallic layer form a sheet that can be curved or bent along its longitudinal axis so as to form a shape suitable for at least partially surrounding one or more conductors.   
     
     
         17 . The tape of  claim 16 , wherein the metallic layer comprises a plurality of metal inclusions. 
     
     
         18 . The tape of  claim 17 , wherein the plurality of metal inclusions comprises any of silver, aluminum, copper, gold, bronze, tin, zinc, iron, nickel, indium, gallium, stainless steel and combinations thereof. 
     
     
         19 . The tape of  claim 17 , further comprising a plurality of carbon fibers. 
     
     
         20 . The tape of  claim 16 , wherein the polymeric substrate layer comprises a polyolefin, a fluoropolymer, or a combination thereof. 
     
     
         21 . The tape of  claim 20 , wherein the fluoropolymer comprises a perfluoropolymer. 
     
     
         22 . The tape of  claim 21 , wherein the perfluoropolymer comprises any of FEP, MFA, PFA, PVF, PTFE, ETFE, ECTFE, PVDF, and a combination thereof. 
     
     
         23 . The tape of  claim 16 , wherein the electrically conductive inclusions comprises a volume fraction of the tape in a range of about 1% to about 40%. 
     
     
         24 . The tape of  claim 16 , wherein the polymeric substrate layer is foamed.