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US-12617707-B2 - Optical fiber and a glass preform manufacturing method

US12617707B2US 12617707 B2US12617707 B2US 12617707B2US-12617707-B2

Abstract

The present disclosure relates to a method and an extrusion apparatus ( 100, 200 ) to manufacture a soot preform ( 130 ). The extrusion apparatus ( 100 and 200 ) includes a feed-hopper ( 104 ) to feed silica slurry ( 102 ) which is pushed within the barrel ( 106 ), an iris frame ( 116 ) exhibiting a variable diameter to control a diameter of the soot preform ( 130 ), drying furnace ( 118 ), debinding furnace ( 122 ) eliminates moisture and one or more stabilized binders in the soot preform ( 130 ) to obtain a glass preform ( 138 ) from which an optical fiber ( 142 ) is drawn.

Inventors

  • Debangshu Debnath
  • SAIKISHORE CHADARAM
  • Sandeep Gaikwad
  • Sudhakar Reddy

Assignees

  • STERLITE TECHNOLOGIES LIMITED

Dates

Publication Date
20260505
Application Date
20230920
Priority Date
20230329

Claims (8)

  1. 1 . An extrusion apparatus ( 100 , 200 ) to manufacture a dried soot preform ( 130 ) characterized in that: a feed-hopper ( 104 ) adapted to feed silica slurry ( 102 ); a barrel ( 106 ) that is disposed beneath the feed-hopper ( 104 ) and adapted to receive the silica slurry ( 102 ), wherein the silica slurry ( 102 ) is pushed within the barrel ( 106 ); a die header ( 114 ) to extrude the silica slurry ( 102 ) such that the silica slurry ( 102 ) is cladded on a core rod ( 128 ) to form the soot preform ( 130 ), wherein the die header ( 114 ) comprises an iris frame ( 116 ); and the iris frame ( 116 ) further comprising: a plurality of vanes ( 302 ) such that each vane of the plurality of vanes ( 302 ) is adapted to move in a radial direction of the iris frame ( 116 ), wherein upon movement of each vane of the plurality of vanes ( 302 ), a central orifice ( 306 ) is created that exhibits a variable diameter, and wherein variation in the diameter of the central orifice ( 306 ) controls the diameter of the soot preform ( 130 ) to form a conical portion ( 134 ) at an end of the soot preform ( 130 ); and a drying furnace ( 118 ) that is disposed beneath the iris frame ( 116 ) and adapted to eliminate physisorbed moisture present in the soot preform ( 130 ) to produce a dried soot preform ( 132 ).
  2. 2 . The extrusion apparatus ( 100 , 200 ) as claimed in claim 1 , wherein the extrusion apparatus ( 100 , 200 ) comprises one or more screws ( 108 ) that are disposed within the barrel ( 106 ) such that the one or more screws ( 108 ) are adapted to mix the silica slurry and push the silica slurry towards the iris frame ( 116 ).
  3. 3 . The extrusion apparatus ( 100 , 200 ) as claimed in claim 1 , wherein the extrusion apparatus ( 100 , 200 ) comprises: a debinding furnace ( 122 ) that is coupled to the drying furnace ( 118 ) and adapted to eliminate one or more stabilized binders and other one or more additives from the dried soot preform ( 132 ) to produce a green body ( 136 ), wherein a glass preform ( 138 ) is obtained from the green body ( 136 ) such that an optical fiber ( 142 ) is drawn from the glass preform ( 138 ).
  4. 4 . The extrusion apparatus ( 100 , 200 ) as claimed in claim 1 , wherein (i) 70% of silica particles of the silica slurry ( 102 ) have dimension greater than 16 microns and (ii) 30% of silica particles of the silica slurry ( 102 ) have dimension smaller than 16 microns.
  5. 5 . The extrusion apparatus ( 100 , 200 ) as claimed in claim 4 , wherein the silica slurry ( 102 ) is prepared by mixing one or more solvents in a range of 10% to 30% with respect to the silica particles and the one or more solvents are one of, water-based solvents, alcohol-based solvents, and keto-based solvents.
  6. 6 . The extrusion apparatus ( 100 , 200 ) as claimed in claim 4 , wherein the silica slurry ( 102 ) is prepared by mixing one or more binders in a range of 0.01% to 5% with respect to the silica particles and each binder of the one or more binders is one of, a polypropylene carbonate, a polyvinyl alcohol, a polystyrene, a camphor, a gelatin-based agar, and a stabilizing agent selected from dispersant, polymerizing initiator, and plasticizer.
  7. 7 . The extrusion apparatus ( 100 , 200 ) as claimed in claim 5 , wherein the silica slurry ( 102 ) comprises the silica particles that lie in a range of 40% to 80%, the one or more binders that lie in a range of 1% to 3%, and the one or more solvents that lie in a range of 17% to 59%.
  8. 8 . The extrusion apparatus ( 100 , 200 ) as claimed in claim 1 , wherein a diameter of the soot preform ( 130 ) is varied in a range of 35 mm to 350 mm with a deviation of +1 mm.

Description

COPYRIGHT STATEMENT A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Indian Application No. 202311023174 titled “OPTICAL FIBER AND A GLASS PREFORM MANUFACTURING METHOD” filed by the applicant on Mar. 29, 2023, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION Embodiments of the present invention relate to the field of telecommunication fiber cables and more particularly, relate to an apparatus to manufacture an optical fiber and a glass preform and a method thereof. DESCRIPTION OF THE RELATED ART Optical fiber is the leading alternative to traditional materials used for data signal communication such as copper wiring. These are essentially ultra-thin light conduits, wherein light is pumped into one end, propagates forward within and through the fiber, whether bent or straight, and ultimately emerges at the other end. Optical fiber is now widely utilized in a variety of electronic devices and systems to facilitate the high-speed communication of voice, video, and data signals at high bandwidths. Optical fibers are widely used in optical cables. Generally, an optical fiber is made of a core that transmits light and a cladding that surrounds the core. The refractive index of the core is generally higher than the refractive index of the cladding. Usually, optical fibers are drawn from a glass preform, which is a cylindrical body made up of glass. Conventional glass preform manufacturing techniques have low deposition efficiency, which leads to loss in capturing of silica soot particles. Furthermore, manufacturing time is on the higher side (for example more than 15 hours). Further, the use of a vacuum to close the centerline and other holes in the optical fiber preforms has many drawbacks as such vacuum forces can result in a nonsymmetrical centerline profile of the cane. US patent application U.S. Pat. No. 5,169,421A discloses manufacturing of a silica glass optical preform using an extrusion apparatus. The extrusion apparatus has a ring-shaped die that is expanded and contracted by means of hydraulic pressure for varying the outlet diameter and subsequently varying the diameter of the silica glass optical preform. Japanese patent application JPH0680436A discloses manufacturing of a porous optical fiber preform by an extrusion apparatus. The extrusion apparatus uses a plastic material for the formation of a cladding layer on the outer portion of the glass core. Yet another US patent application U.S. Pat. No. 5,314,520A discloses a method for manufacturing optical fiber preform that requires a porous preform to produce an optical fiber exerting high mechanical strength, can be efficiently manufactured without generating bubbles. Furthermore, conventional techniques/apparatus/methods of manufacturing optical fiber and glass preform are very costly and cannot exhibit any kind of dimensional variation for the optical fiber and glass preform being manufactured. This increases the cost of production of optical fiber. Along-with this, maintenance cost associated with the conventional apparatus is high. Accordingly, to overcome the disadvantages of the prior art, there is an urgent need for a technical solution that overcomes the above-stated limitations in the prior arts by providing an efficient and effective apparatus and method to manufacture optical fibers and glass preforms. Thus. the present invention provides an apparatus for constraining an optical fiber in a draw tower and method thereof. SUMMARY OF THE INVENTION Embodiments of the present invention relate to a method for manufacturing an optical fiber comprising steps of forming a soot preform using an extrusion apparatus, drying by way of a drying furnace the soot preform for eliminating physisorbed moisture present in the soot preform such that upon drying a dried soot preform is produced, sintering by way of a sinter furnace the dried soot preform to obtain a glass preform and drawing by way of a draw furnace the glass preform to manufacture the optical fiber. Further, the step of forming soot preform using an extrusion apparatus characterizes preparing silica slurry by mixing one or more solvents, one or more binders, one or more additives, and silica particles, pushing by way of one or more screws disposed within a barrel, the silica slurry from an inlet end to an outlet end of the barrel and extruding by way of a die header such that the silica slurry is cladded on a core rod to form the soot preform. In particular, the die header comprises an iris frame to vary a diameter of the soot preform. In accordance with an embodiment of the