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 communications cable, comprising:
 at least a pair of insulated twisted conductors; and   a tape at least partially wrapped around said twisted pair of conductors;   wherein said tape comprises a flexible, polymeric sheet and a plurality of electrically conductive inclusions distributed therein for electromagnetically shielding said twisted pair.   
     
     
         2 . The communications cable of  claim 1 , wherein the plurality of electrically conductive inclusions comprises a plurality of metal inclusions. 
     
     
         3 . The communications cable 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 combinations thereof. 
     
     
         4 . The communications cable of  claim 2 , wherein the plurality of electrically conductive inclusions further comprises a plurality of carbon fibers. 
     
     
         5 . The communications cable of  claim 1 , wherein the polymeric sheet comprises a polyolefin, a fluoropolymer, or a combination thereof. 
     
     
         6 . The communications cable of  claim 5 , wherein the fluoropolymer comprises a perfluoropolymer. 
     
     
         7 . The communications cable of  claim 6 , wherein the perfluoropolymer comprises any of FEP, MFA and PFA. 
     
     
         8 . The communications cable of  claim 1 , wherein the electrically conductive inclusions comprises a volume fraction of the tape in a range of about 1% to about 40%. 
     
     
         9 . The communications cable of  claim 1 , wherein the electrically conductive inclusions comprises a volume fraction of the tape in a range of about 5% to about 10%. 
     
     
         10 . The communications cable of  claim 1 , wherein the polymeric sheet is foamed. 
     
     
         11 . The communications cable of  claim 1 , wherein the tape has a thickness in a range of about 0.001 inches to about 0.02 inches. 
     
     
         12 . The communications cable of  claim 1 , wherein said tape is not electrically grounded. 
     
     
         13 . The communications cable of  claim 1 , wherein said tape comprises a plurality of polymeric fibers. 
     
     
         14 . The communications cable 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 communications cable 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 . The communications cable of  claim 1 , wherein said cable is an unshielded cable. 
     
     
         17 . The communications cable of  claim 1 , wherein said cable is a shielded cable. 
     
     
         18 . The communications cable of  claim 1 , further comprising a jacket that at least partially surrounds said tape and said twisted pair of conductors. 
     
     
         19 . The communications cable of  claim 18 , wherein said jacket provides shielding of electromagnetic radiation. 
     
     
         20 . The communications cable of  claim 19 , wherein said jacket provides shielding of electromagnetic radiation at wavelengths in a range of about 1 MHz to about 40 GHz.