# US 9,435,978 B1 · Water-resistant optical fiber cables > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,435,978 B1 - Document ID: US9435978B1 - Status: Granted - Kind: B1 - Application number: 13/916,242 - Filed: 2013-06-12 - Granted: 2016-09-06 - Earliest claimed: 2012-06-14 - Assignees: Superior Essex Communications LP - Applicants: Superior Essex Communications LP - Inventors: Jeffrey Scott Laws; Christopher W McNutt - Web page: https://patentgrep.com/patent/US9435978B1 ## CPC - G02B 6/44384: {the means comprising water blocking or hydrophobic materials (G02B6/4439, G02B6/4479 take precedence)} - G02B 6/4483: {Injection or filling devices} - G02B 6/4485: {Installing in protective tubing by fluid drag during manufacturing} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Water-resistant optical fiber cables and associated methods for forming water-resistant optical fiber cables are provided. A cable may include an outer jacket that defines a cable core. At least one optical fiber may be positioned within the cable core and encapsulated within a suitable sheath, such as a buffer tube. Additionally, a plurality of discrete water swellable fibers may be loosely positioned within the cable to provide water-resistance for the at least one optical fiber. ## Claims ### Claim 1 A cable, comprising: an outer jacket defining a cable core; a buffer tube situated within the cable core; at least one optical fiber positioned within the buffer tube; and a plurality of discrete elongated water swellable fibers loosely positioned within the buffer tube, each of the water swellable fibers having a longest dimension between approximately two millimeters and approximately two hundred millimeters, wherein the plurality of water swellable fibers are not adhered to a longitudinally extending substrate layer. ### Claim 2 (depends on 1) The cable of claim 1, wherein the water swellable fibers comprise sodium polyacrylate. ### Claim 3 (depends on 1) The cable of claim 1, further comprising at least one of (i) friction reducing material, (ii) flame retardant material, or (iii) smoke suppressant material mixed with the water swellable fibers. ### Claim 4 A cable, comprising: at least one optical fiber; a buffer tube formed around the at least one optical fiber along a longitudinal length of the cable; a plurality of discrete and discontinuous elongated water swellable fibers loosely positioned within the buffer tube to provide water penetration resistance for the at least one optical fiber, each of the water swellable fibers having a longest dimension between approximately two millimeters and approximately two hundred millimeters; and an outer jacket formed around the buffer tube. ### Claim 5 (depends on 4) The cable of claim 4, wherein the plurality of water swellable fibers are not adhered to a longitudinally extending substrate layer. ### Claim 6 (depends on 4) The cable of claim 4, wherein the water swellable fibers comprise pulped superabsorbent yarn fibers. ### Claim 7 (depends on 4) The cable of claim 4, wherein the water swellable fibers comprise sodium polyacrylate. ### Claim 8 (depends on 4) The cable of claim 4, further comprising a friction-inducing material mixed with the water swellable fibers. ### Claim 9 (depends on 4) The cable of claim 4, further comprising at least one of (i) talc particles, (ii) polymeric microspheres, (iii) foam rubber particles, or (iv) flame retardant particles mixed with the water swellable fibers. ### Claim 10 (depends on 4) The cable of claim 4, wherein the water swellable fibers are air blown into the buffer tube. ### Claim 11 (depends on 4) The cable of claim 4, wherein the water swellable fibers are extruded onto the at least one optical fiber prior to formation of the buffer tube. ### Claim 12 (depends on 4) The cable of claim 4, wherein the water swellable fibers are applied to the optical fiber by at least one of physical contact or electrostatic attraction. ### Claim 13 (depends on 4) The cable of claim 4, wherein the water swellable fibers are positioned at discontinuous intervals along the longitudinal length of the cable. ### Claim 14 A cable comprising: a cable core; one or more transmission media positioned in the cable core; a sheath surrounding the cable core; and discrete and discontinuous elongated water swellable particles loosely positioned within the sheath to provide water penetration resistance for the cable core, each of the water swellable particles having a longest dimension between approximately two millimeters and approximately two hundred millimeters, wherein none of the water swellable particles are adhered to a substrate layer. ### Claim 15 (depends on 14) The cable of claim 14, wherein the water swellable particles comprise sodium polyacrylate. ### Claim 16 (depends on 14) The cable of claim 14, further comprising a friction-inducing material mixed with the water swellable particles. ### Claim 17 A method for forming a cable, the method comprising: providing at least one optical fiber; forming a buffer tube around the at least one optical fiber; loosely positioning discrete and discontinuous elongated water swellable fibers within the buffer tube, each of the water swellable fibers having a longest dimension between approximately two millimeters and approximately two hundred millimeters; and forming an outer jacket over the buffer tube. ### Claim 18 (depends on 17) The method of claim 17, wherein loosely positioning discrete water swellable fibers within the buffer tube comprises air blowing the water swellable fibers into the buffer tube. ### Claim 19 (depends on 17) The method of claim 17, wherein loosely positioning discrete water swellable fibers within the buffer tube comprises extruding the water swellable fibers onto the at least one optical fiber prior to forming the buffer tube. ### Claim 20 (depends on 17) The method of claim 17, wherein loosely positioning discrete water swellable fibers within the buffer tube comprises applying the water swellable fibers to the at least one optical fiber by at least one of physical contact or electrostatic attraction prior to forming the buffer tube.