# US 2010/0166375 A1 · Perforated Water-Blocking Element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166375 A1 - Document ID: US20100166375A1 - Status: Published application - Kind: A1 - Application number: 12/648,794 - Filed: 2009-12-29 - Published: 2010-07-01 - Earliest claimed: 2008-12-30 - Assignees: Draka Comteq B.V. - Inventors: Don Parris - Web page: https://patentgrep.com/patent/US20100166375A1 ## CPC - G02B 6/44384: {the means comprising water blocking or hydrophobic materials (G02B6/4439, G02B6/4479 take precedence)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract The present invention provides optical-fiber communication cables with an improved water-blocking element that reduces or eliminates microbending caused by the water-swellable particulate powders by employing such water-swellable powders in conjunction with a smooth but perforated compression-resistant carrier tape. The water-blocking element is deployed within optical-fiber buffer tubes to water-block the buffer tubes and to minimize microbending that can occur when water-swellable particulate powders press against optical fibers. ## Claims ### Claim 1 An optical-fiber cable, comprising: an optical fiber; a buffer tube enclosing said optical fiber; a water-blocking element positioned between said optical fiber and said buffer tube, said water-blocking element comprising (i) a substantially non-fibrous, compression-resistant carrier tape defining a plurality of perforations and (ii) a water-swellable particulate powder bonded to said perforated carrier tape, wherein said water-blocking element at least partially surrounds said optical fiber and wherein said perforated carrier tape is positioned adjacent to said optical fiber and said water-swellable powder is positioned opposite said optical fiber; and a polymeric cable jacket surrounding said buffer tube. ### Claim 2 (depends on 1) An optical-fiber cable according to claim 1, wherein: said buffer tube encloses a plurality of optical fibers, said buffer tube possessing a filling coefficient of at least about 0.20; and the optical-fiber cable complies with the GR-20-CORE temperature cycling requirement. ### Claim 3 (depends on 1) An optical-fiber cable according to claim 1, wherein said perforated carrier tape possesses a density of at least about 0.90 g/cm3. ### Claim 4 (depends on 1) An optical-fiber cable according to claim 1, wherein said perforated carrier tape is a non-foamed carrier tape. ### Claim 5 (depends on 1) An optical-fiber cable according to claim 1, wherein said perforated carrier tape is substantially incompressible. ### Claim 6 (depends on 1) An optical-fiber cable according to claim 1, wherein said perforated carrier tape possesses Shore A hardness of more than about 25. ### Claim 7 (depends on 1) An optical-fiber cable according to claim 1, wherein the plurality of perforations defined by said substantially non-fibrous, compression-resistant carrier tape are sized to hinder the dry migration of said water-swellable particulate powder through said perforated carrier tape. ### Claim 8 An optical-fiber cable, comprising: an optical fiber; a buffer tube enclosing said optical fiber; a water-blocking element positioned between said optical fiber and said buffer tube, said water-blocking element comprising (i) first and second substantially non-fibrous, compression-resistant carrier tapes, at least one of said first and second carrier tapes defining a plurality of perforations and (ii) a water-swellable particulate powder disposed between said first and second carrier tapes, wherein said water-blocking element at least partially surrounds said optical fiber; and a polymeric cable jacket surrounding said buffer tube. ### Claim 9 (depends on 8) An optical-fiber cable according to claim 8, wherein each of said first and second carrier tapes defines a plurality of perforations. ### Claim 10 (depends on 8) An optical-fiber cable according to claim 8, wherein: said buffer tube encloses a plurality of optical fibers, said buffer tube possessing a filling coefficient of at least about 0.30; and the optical-fiber cable complies with the GR-20-CORE temperature cycling requirement. ### Claim 11 (depends on 8) An optical-fiber cable according to claim 8, wherein said first and second carrier tapes each possess a density of at least about 0.90 g/cm3. ### Claim 12 (depends on 8) An optical-fiber cable according to claim 8, wherein said first and second carrier tapes are substantially incompressible. ### Claim 13 An optical-fiber cable, comprising: an optical fiber; a buffer tube enclosing said optical fiber; a water-blocking element positioned between said optical fiber and said buffer tube, said water-blocking element comprising (i) a fibrous carrier tape defining a plurality of discrete perforations and (ii) a water-swellable particulate powder bonded to said perforated fibrous carrier tape, wherein said water-blocking element at least partially surrounds said optical fiber and wherein said perforated fibrous carrier tape is positioned adjacent to said optical fiber and said water-swellable powder is positioned opposite said optical fiber; and a polymeric cable jacket surrounding said buffer tube. ### Claim 14 (depends on 13) An optical-fiber cable according to claim 13, wherein: said buffer tube encloses a plurality of optical fibers, said buffer tube possessing a filling coefficient of at least about 0.20; and the optical-fiber cable complies with the GR-20-CORE temperature cycling requirement. ### Claim 15 (depends on 14) An optical-fiber cable according to claim 14, wherein: said buffer tube encloses a plurality of bend-insensitive optical fibers, said buffer tube possessing a filling coefficient of at least about 0.50; and the optical-fiber cable complies with the GR-20-CORE temperature cycling requirement. ### Claim 16 (depends on 13) An optical-fiber cable according to claim 13, wherein said perforated fibrous carrier tape possesses Shore A hardness of more than about 25. ### Claim 17 (depends on 13) An optical-fiber cable according to claim 13, wherein said perforated fibrous carrier tape possesses Shore A hardness of more than about 45. ### Claim 18 (depends on 13) An optical-fiber cable according to claim 13, wherein said perforated fibrous carrier tape is a water-insoluble carrier tape that maintains its strength and structural integrity when immersed in water. ### Claim 19 (depends on 13) An optical-fiber cable according to claim 13, wherein the plurality of perforations defined by said perforated fibrous carrier tape are sized to hinder the dry migration of said water-swellable particulate powder through said perforated fibrous carrier tape. ### Claim 20 (depends on 13) An optical-fiber cable according to claim 13, wherein said perforated fibrous carrier tape comprises a substrate formed from a plurality of polymeric fibers, wherein the density of said substrate is at least about 80 percent of the density of said polymeric fibers. ### Claim 21 (depends on 13) An optical-fiber cable according to claim 13, wherein said perforated fibrous carrier tape comprises a substrate formed from a plurality of polymeric fibers, wherein the density of said substrate is at least about 90 percent of the density of said polymeric fibers. ### Claim 22 (depends on 13) An optical-fiber cable according to claim 13, wherein said perforated fibrous carrier tape comprises natural fibers. ### Claim 23 (depends on 13) An optical-fiber cable according to claim 13, wherein said perforated fibrous carrier tape comprises paper. ### Claim 24 (depends on 13) An optical-fiber cable according to claim 13, wherein said perforated fibrous carrier tape comprises parchment paper. ### Claim 25 An optical-fiber cable, comprising: an optical fiber; a buffer tube enclosing said optical fiber; a water-blocking element positioned between said optical fiber and said buffer tube, said water-blocking element comprising (i) first and second fibrous carrier tapes, at least one of said first and second carrier tapes defining a plurality of perforations and interstices that facilitate the passage of water and (ii) a water-swellable particulate powder disposed between said first and second carrier tapes, wherein said water-blocking element at least partially surrounds said optical fiber; and a polymeric cable jacket surrounding said buffer tube. ### Claim 26 (depends on 25) An optical-fiber cable according to claim 25, wherein each of said carrier tapes defines a plurality of perforations. ### Claim 27 (depends on 25) An optical-fiber cable according to claim 25, wherein: said buffer tube encloses a plurality of optical fibers, said buffer tube possessing a filling coefficient of at least about 0.30; and the optical-fiber cable complies with the GR-20-CORE temperature cycling requirement. ### Claim 28 (depends on 25) An optical-fiber cable according to claim 25, wherein said first and second carrier tapes are water-insoluble carrier tapes that maintain their strength and structural integrity when immersed in water. ### Claim 29 (depends on 25) An optical-fiber cable according to claim 25, wherein said first and second carrier tapes comprise a substrate formed from a plurality of polymeric fibers, wherein the density of said substrate is at least about 80 percent of the density of said polymeric fibers. ### Claim 30 (depends on 25) An optical-fiber cable according to claim 25, wherein said first and second carrier tapes are formed from a plurality of natural fibers.