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A fiber optic assembly includes a buffer tube forming an elongate passage and a plurality of optical fibers positioned therein. The buffer tube includes at least one layer of a composite material that includes a base material and a filler material blended therein. Particles of the filler material ha

A fiber optic assembly includes a buffer tube forming an elongate passage and a plurality of optical fibers positioned therein. The buffer tube includes at least one layer of a composite material that includes a base material and a filler material blended therein. Particles of the filler material have an acicular structure, having a longest dimension that is on average at least ten times a narrowest dimension of the particles. Further the buffer tube has kink resistance.

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1. A fiber optic assembly, comprising: a plurality of optical fibersa buffer tube forming an elongate passage, wherein the plurality of optical fibers are positioned in the passage of the buffer tube,wherein the buffer tube comprises at least one layer of a composite material, wherein the composite

1. A fiber optic assembly, comprising: a plurality of optical fibersa buffer tube forming an elongate passage, wherein the plurality of optical fibers are positioned in the passage of the buffer tube,wherein the buffer tube comprises at least one layer of a composite material, wherein the composite material of the buffer tube comprises a base material and a filler material blended into the base material,wherein particles of the filler material have an acicular structure, the particles having a longest dimension that is on average at least ten times a narrowest dimension of the particles, andwherein the buffer tube has kink resistance such that when the buffer tube is formed into a loop of 85 millimeters in diameter with a plastic ring of about 2 centimeters in interior diameter holding the cross-over point of the loop, and when the loop is then constricted by fixing one side of the buffer tube and drawing the other side of the buffer tube through the ring at a rate of 250 millimeters per minute to decrease the size of the loop, kinking of the buffer tube occurs when the loop is 20 millimeters or less in diameter, where the diameter at kinking is the diameter corresponding to a peak drawing force applied that is then accompanied by a drop in at least 10% of that peak force thereafter upon continued constricting of the loop. 2. The assembly of claim 1, wherein kink performance of the buffer tube has little susceptibility to hydrolysis weakening such that the diameter of the loop resulting in kinking does not decrease by more than 25% after 30 days of aging of the buffer tube at 85 degrees Centigrade and at 85% relative humidity. 3. The assembly of claim 2, wherein the drawing force required to kink the buffer tube by constricting the loop is at least 0.5 newtons. 4. The assembly of claim 1, wherein crush performance of the buffer tube has little susceptibility to hydrolysis weakening such that the load required for 25% deflection does not decrease by more than 20% after 30 days of aging of the buffer tube at 85 degrees Centigrade and at 85% relative humidity. 5. The assembly of claim 1, wherein the base material of the buffer tube comprises at least one of a polypropylene copolymer and a thermoplastic polyolefin. 6. The assembly of claim 5, wherein the base material is a thermoplastic polyolefin having an unfilled modulus of elasticity in the range of 1450-1700 megapascals. 7. The assembly of claim 6, wherein the filler material raises the modulus of elasticity of the base material such that the composite material of the buffer tube has a modulus of elasticity of at least 2000 megapascals. 8. The assembly of claim 5, wherein the filler material comprises a solid powder. 9. The assembly of claim 8, wherein the filler material comprises an inorganic material. 10. The assembly of claim 8, wherein the ratio of the filler material to the base material by volume is in the range of 2 to 40 percent. 11. The assembly of claim 8, wherein the composite material facilitates manufacture of particularly narrow buffer tubes, such that the buffer tube has an outer diameter of 2.4 millimeters or less and contains at least twelve optical fibers. 12. The assembly of claim 11, wherein the buffer tube has an outer diameter of 2.2 millimeters or less. 13. A fiber optic assembly, comprising: a plurality of optical fibers;a buffer tube forming an elongate passage, wherein the plurality of optical fibers are positioned in the passage of the buffer tube,wherein the buffer tube comprises a composite material, wherein the composite material of the buffer tube comprises a base material and a filler material blended into the base material, wherein the ratio of the filler material to the base material by volume is in the range of 2 to 40 percent, wherein the base material comprises at least one of a polypropylene copolymer and a thermoplastic polyolefin, wherein the filler material comprises a solid powder, wherein the filler material comprises an inorganic material, wherein particles of the filler material have an acicular structure, andwherein the buffer tube has strong kink resistance such that when the buffer tube is formed into a loop of 85 millimeters in diameter with a low-friction plastic ring of about 2 centimeters in interior diameter holding the cross-over point of the loop, and when the loop is then constricted by fixing one side of the buffer tube and drawing the other side of the buffer tube through the ring at a rate of 250 millimeters per minute to decrease the size of the loop, kinking of the buffer tube occurs when the loop is 20 millimeters or less in diameter, where the diameter at kinking is the diameter corresponding to the peak drawing force applied that is then accompanied by a drop in at least 10% of that peak force thereafter upon continued constricting of the loop; andwater-swellable material positioned in the passage of the buffer tube. 14. The assembly of claim 13, wherein the water-swellable material comprises a powder of superabsorbent polymer having an average volume-based particle size of 60 micrometers of less. 15. The assembly of claim 14, wherein the water-swellable powder lines the passage. 16. The assembly of claim 14, wherein the water-swellable powder is attached to the interior of the cavity. 17. The assembly of claim 13, wherein the composite material has a modulus of elasticity of at least 2000 megapascals. 18. The assembly of claim 13, wherein the buffer tube has an outer diameter of 2.4 millimeters or less and contains at least twelve optical fibers. 19. The assembly of claim 13, wherein crush performance of the buffer tube has little susceptibility to hydrolysis weakening such that the load required for 25% deflection does not decrease more than 20% after 30 days of aging of the buffer tube at 85 degrees Centigrade and at 85% relative humidity. 20. The assembly of claim 13, wherein kink performance of the buffer tube has little susceptibility to hydrolysis weakening such that the diameter of the loop resulting in kinking does not decrease more than 25% after 30 days of aging of the buffer tube at 85 degrees Centigrade and at 85% relative humidity.