초록

A fiber-optic cable with low buffer insertion force, significant kink resistance, and improved thermal performance incorporating a dual layer buffer of a low density material beneath a continuous seamless high modulus material without compromising low smoke, toxicity, and flammability.

대표청구항 ▼

What is claimed is: 1. A fiber-optic cable comprising: at least one optical fiber, the optical fiber including a core and a cladding around the core; a primary buffer around the optical fiber; a multi-layer secondary buffer positioned around the optical fiber and primary buffer, the secondary buffe

What is claimed is: 1. A fiber-optic cable comprising: at least one optical fiber, the optical fiber including a core and a cladding around the core; a primary buffer around the optical fiber; a multi-layer secondary buffer positioned around the optical fiber and primary buffer, the secondary buffer including at least a first buffer layer formed of PTFE and a second buffer layer overlaying the first buffer layer; an outer surface of the PTFE of the first buffer layer being pre-treated to modify the outer surface for receiving application of the second buffer layer; the second buffer layer being an homogenous and continuous material layer applied over the pretreated outer surface of the first buffer layer in a continuous application process including at least one of a coating or an extrusion process; the second buffer layer having a thickness in the range of 0.0005 to 0.0050 inches; a strength member layer positioned around the primary and secondary buffers; an outer jacket positioned around the strength member. 2. The fiber-optic cable of claim 1, wherein the first buffer layer includes an expanded PTFE layer having a density in the range of 0.3 to 1.9 gms/cc. 3. The fiber-optic cable of claim 1 wherein the second buffer layer is formed of a material including at least one material selected from the group of polyphenylene sulphide, polyphenylene sulfone, polyphenylene oxide, polyetherketones, liquid crystal polymers, polycarbonates, polyesters, polyamides, and polyimides. 4. The fiber-optic cable of claim 1, wherein the first buffer layer includes expanded PTFE. 5. The fiber-optic cable of claim 1, wherein the second buffer layer includes a high flexural modulus material having a flexural modulus in the range of 1.0 to 10.0 GPa. 6. The fiber-optic cable of claim 1 wherein the continuous application process is a coating process including at least one of the following: powder coating, dip coating and dispersion coating. 7. The fiber-optic cable of claim 1 wherein the continuous application process is an extrusion process including at least one of the following: screw extrusion and melt pump extrusion. 8. The fiber-optic cable of claim 1 wherein the second buffer layer is formed of a polyimide material. 9. The fiber-optic cable of claim 1 wherein the outer surface of the first buffer layer is pre-treated by at least one of surface etching, applying thin surface coatings and drying the coatings, and plasma treating to modify the outer surface of the first buffer layer. 10. A method for forming a fiber-optic cable comprising: presenting an optical fiber having a core and a cladding around the core; a primary buffer being positioned around the optical fiber; positioning a multi-layer secondary buffer around at least one optical fiber by: forming a first buffer layer of PTFE on the primary buffer around the optical fiber; pre-treating an outer surface of the PTFE of the first buffer layer to modify the outer surface for receiving application of a second buffer layer; forming a continuous second buffer layer from an homogenous material by applying the second buffer layer over the pretreated outer surface of the first buffer layer in a continuous application process including at least one of a coating process or an extrusion process; forming the second buffer layer to have a thickness in the range of 0.0005 to 0.0050 inches; positioning a strength member layer around the primary and secondary buffers; and positioning an outer jacket around the strength member. 11. The method of claim 10 further comprising forming the second buffer layer with a continuous layer of a polyimide material. 12. The method of claim 10 wherein the outer surface of the first buffer layer is pre-treated by at least one of surface etching, applying thin surface coatings and drying the coatings, and plasma treating to modify the outer surface of the first buffer layer. 13. The method of claim 10 further comprising forming the first buffer layer with a continuous layer of expanded PTFE. 14. The method of claim 13, wherein the first buffer layer includes an expanded PTFE layer having a density in the range of 0.3 to 1.9 gms/cc. 15. The method of claim 10 wherein the material for the second buffer layer includes a high flexural modulus material having a flexural modulus in the range of 1.0 to 10.0 GPa. 16. The method of claim 10 wherein the continuous application process is a coating process including at least one of the following: powder coating, dip coating and dispersion coating. 17. The method of claim 10 wherein the continuous application process is an extrusion process including at least one of the following: screw extrusion and melt pump extrusion. 18. The method of claim 10 further comprising forming the second buffer layer with a continuous layer formed of a material including at least one material selected from the group of polyphenylene sulphide, polyphenylene sulfone, polyphenylene oxide, polyetherketones, liquid crystal polymers, polycarbonates, polyesters, polyamides, and polyimides. 19. A fiber-optic cable comprising: at least one optical fiber, the optical fiber including a core and a cladding around the core; a primary buffer around the optical fiber; a multi-layer secondary buffer positioned around the optical fiber and primary buffer and including at least a first buffer layer formed of PTFE and a second buffer layer overlaying the first buffer layer; an outer surface of the PTFE of the first buffer layer being pre-treated to modify the outer surface for receiving application of the second buffer layer; the second buffer layer being a continuous material layer applied over the pretreated outer surface of the first buffer layer using a continuous application process including at least one of a coating or an extrusion process; the second buffer layer having a thickness in the range of 0.0005 to 0.0050 inches. 20. The fiber-optic cable of claim 19, wherein the first buffer layer includes an expanded PTFE layer having a density in the range of 0.3 to 1.9 gms/cc. 21. The fiber-optic cable of claim 19, wherein the second buffer layer includes a high flexural modulus material having a flexural modulus in the range of 1.0 to 10.0 GPa. 22. The fiber-optic cable of claim 19, wherein the second buffer layer is formed of a polyimide material. 23. The fiber-optic cable of claim 19 wherein the second buffer layer is formed of a material including at least one material selected from the group of polyphenylene sulphide, polyphenylene sulfone, polyphenylene oxide, polyetherketones, liquid crystal polymers, polycarbonates, polyesters, polyamides, and polyimides. 24. The fiber-optic cable of claim 19 wherein the outer surface of the first buffer layer is pre-treated by at least one of surface etching, applying thin surface coatings and drying the coatings, and plasma treating to modify the outer surface of the first buffer layer. 25. The fiber-optic cable of claim 19 wherein the continuous application process is a coating process including at least one of the following: powder coating, dip coating and dispersion coating. 26. The fiber-optic cable of claim 19 wherein the continuous application process is an extrusion process including at least one of the following: screw extrusion and melt pump extrusion.