WO1983002268A1 - A device in equipment for drawing glass fibres - Google Patents

A device in equipment for drawing glass fibres Download PDF

Info

Publication number
WO1983002268A1
WO1983002268A1 PCT/SE1982/000432 SE8200432W WO8302268A1 WO 1983002268 A1 WO1983002268 A1 WO 1983002268A1 SE 8200432 W SE8200432 W SE 8200432W WO 8302268 A1 WO8302268 A1 WO 8302268A1
Authority
WO
WIPO (PCT)
Prior art keywords
fibre
chamber
cooling
glass
equipment
Prior art date
Application number
PCT/SE1982/000432
Other languages
French (fr)
Inventor
L M Ericsson Telefonaktiebolaget
Original Assignee
Vacha, Lubos, Josef, Bohuslav
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Vacha, Lubos, Josef, Bohuslav filed Critical Vacha, Lubos, Josef, Bohuslav
Priority to JP83500072A priority Critical patent/JPS58502200A/en
Publication of WO1983002268A1 publication Critical patent/WO1983002268A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C25/00—Surface treatment of fibres or filaments made from glass, minerals or slags
    • C03C25/10—Coating
    • C03C25/12—General methods of coating; Devices therefor
    • C03C25/16—Dipping
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/02—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor
    • C03B37/022—Manufacture of glass fibres or filaments by drawing or extruding, e.g. direct drawing of molten glass from nozzles; Cooling fins therefor from molten glass in which the resultant product consists of different sorts of glass or is characterised by shape, e.g. hollow fibres, undulated fibres, fibres presenting a rough surface
    • C03B37/023—Fibres composed of different sorts of glass, e.g. glass optical fibres, made by the double crucible technique
    • C03B37/0235—Thermal treatment of the fibre during the drawing process, e.g. cooling
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C25/00—Surface treatment of fibres or filaments made from glass, minerals or slags
    • C03C25/10—Coating
    • C03C25/104—Coating to obtain optical fibres
    • C03C25/106—Single coatings

Definitions

  • the invention relates to a device in equipment for drawing optical fibres.
  • Optical fibres are produced by continuous drawing from a melt in a double crucible or from a so-called preform which is heated to a semi-liquid condition- As soon as possible after drawing, the fibre is provided with a coating to increase its strength so that it can be handled without risk for rupture when winding onto a reel and during later cable manufacture.
  • the coating is usually carried out by the drawn glass fibre passing as soon as possible through a bath of coating material, usually heat-curable silicon rubber. This coating method functions well for thinner fibre dimensions.
  • a device in equipment for drawing glass fibres in accordance with the invention includes a cooling means placed after the drawing location, and its character ⁇ izing features are apparent from the appended claims.
  • the numeral 10 denotes a melting crucible for glass, in this case a so-called double crucible of the kind described in the article "Optical Fibres" in the Ericsson Review No 3, 1980, pages 12 and 13. It is primarily intended for producing optical fibres of the so-called step-index type, but can also be used in the production of graded index fibres. It includes an inner crucible 11 containing a glass melt 13 with a high refractive index intended to form the core in the glass fibre, and an outer crucible 12 with a glass melt 14 having a low refractive index and intended to form the sheath or casing of the fibre.
  • the glass melt 13 from the inner crucible runs slowly out through the nozzle 15 in the inner crucible 11, passing through the outer crucible and out through the outer nozzle 16. When it passes the latter nozzle, the core is surrounded by glass from the outer crucible. When the glass melt has passed the outer nozzle 16 a meniscus 17 is formed, and from this the glass is drawn out into a thin fibre 18 with the aid of a capstan means 26.
  • the drawn fibre will have a core of the glass 13 and a cladding of the glass 14.
  • the fibre diameter is dependent on the drawing rate of the capstan means and the outflow rate through the nozzles 15 and 16, the rate in turn depending on the temperature and viscosity of the glass melts.
  • the diameter is measured with a thickness meter 19 which controls the drawing rate of the capstan means with the aid of suitable conventional control equipment.
  • the fibre After drawing, the fibre is sensitive to scratches and contamination, and must therefore be provided as quickly as possible with a protective coating.
  • OM?I takes place in a receptacle 20 containing suitable liquid coating material, e g curable silicon rubber, which is cured in a suitable, unillustrated heating means after it has adhered to the fibre and when the fibre has passed out from the receptacle 20.
  • suitable liquid coating material e g curable silicon rubber
  • a cooling chamber 21, through which the drawn fibre passes is arranged between the drawing nozzle 16 and the receptacle.
  • the cooling chamber 21 comprises a tube 22 of a porous material with very fine open pores.
  • the material may suitably be a porous metal, e g bronze, produced by sintering or some other method.
  • the material can also be of other types, e g microporous ceramics or plastics.
  • a vessel 23 is arranged round the outside of the tube and provided with a supply pipe 24 connected to a source for compressed gas, preferably dry nitrogen gas. The gas passes through the porous tube 22 and into the space 25 around the fibre.
  • the large number of pores in the tube 22 ensures that the gas flow coming into the space 24 is very uniformly distributed round the fibre and the latter, will not be subjected to any transverse forces.
  • the upper opening of the tube 22 is provided with a shield, e g an iris-type aperture, which is solely provided with a fine hole through which the fibre can pass into the tube 22. Due to the cooling, the distance between the drawing nozzle 16 and the receptacle 20 may be shortened considerably.
  • a dried gas suitably nitrogen gas
  • the risk is further decreased of the fibre absorbing water, which heavily reduces the fibre strength by making its way into the microcracks.
  • the fibre passes then through the bath it is cooled such that no curing takes place therein, and the coating will be uniformly distributed around the filament.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Surface Treatment Of Glass Fibres Or Filaments (AREA)
  • Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Abstract

In drawing glass fibres intended for optical transmission, the fibre (18) is allowed to pass through a tubular cooling chamber (21) after drawing, the inner wall (22) of the chamber comprising a porous material with open pores. The chamber (21) is connected to a source of compressed gas, suitably dry nitrogen gas. By cooling the hot fibre is prevented from being contaminated and damaged by air humidity, and the fibre tensional strength is increased by compression stresses being built into the outer layer of the fibre. Furthermore, the fibre is prevented from being so hot that it can cure too early and unevenly the protective coating of a curable plastics, which is applied as soon as possible after drawing, to protect and reinforce the glass fibre.

Description

A DEVICE IN EQUIPMENT FOR DRAWING GLASS FIBRES
TECHNICAL FIELD
The invention relates to a device in equipment for drawing optical fibres.
BACKGROUND ART
Optical fibres are produced by continuous drawing from a melt in a double crucible or from a so-called preform which is heated to a semi-liquid condition- As soon as possible after drawing, the fibre is provided with a coating to increase its strength so that it can be handled without risk for rupture when winding onto a reel and during later cable manufacture.
The coating is usually carried out by the drawn glass fibre passing as soon as possible through a bath of coating material, usually heat-curable silicon rubber. This coating method functions well for thinner fibre dimensions.
DISCLOSURE OF INVENTION
For heavier fibre dimensions, e g 200-300 um, it has been found that the coating becomes uneven if entry into the silicon rubber bath takes place too close to the drawing location. On entry into the bath it has been found that the fibre has such a high temperature that the rubber cures immediately. One is therefore compelled to move the bath further away from the drawing location, with increased risk of microcracks in the fibre and contamination of its surface, above all with dust and moisture. This increased distance results in a lowering of the drawing speed for thick fibres, due to the fibre diameter decreasing because of the weight thereof. Forced cooling of the fibre close to the drawing location has been found difficult to arrange, since lateral forces which can cause rupture easily occur on the fibre.
In accordance with the invention it is possible to increase the cooling heavily, so that the distance between the drawing location and coating bath may be kept short, simultaneously as the fibre can run without being disturbed by the cooling medium. A device in equipment for drawing glass fibres in accordance with the invention includes a cooling means placed after the drawing location, and its character¬ izing features are apparent from the appended claims.
BRIEF DESCRIPTION OF DRAWING
The invention will now be described in detail in conjunction with the appended drawing where Figure 1 schematically illustrates equipment for drawing and coating optical fibres.
MODE FOR CARRYING OUT THE INVENTION
In Figure 1 the numeral 10 denotes a melting crucible for glass, in this case a so-called double crucible of the kind described in the article "Optical Fibres" in the Ericsson Review No 3, 1980, pages 12 and 13. It is primarily intended for producing optical fibres of the so-called step-index type, but can also be used in the production of graded index fibres. It includes an inner crucible 11 containing a glass melt 13 with a high refractive index intended to form the core in the glass fibre, and an outer crucible 12 with a glass melt 14 having a low refractive index and intended to form the sheath or casing of the fibre. The glass melt 13 from the inner crucible runs slowly out through the nozzle 15 in the inner crucible 11, passing through the outer crucible and out through the outer nozzle 16. When it passes the latter nozzle, the core is surrounded by glass from the outer crucible. When the glass melt has passed the outer nozzle 16 a meniscus 17 is formed, and from this the glass is drawn out into a thin fibre 18 with the aid of a capstan means 26. The drawn fibre will have a core of the glass 13 and a cladding of the glass 14.
The fibre diameter is dependent on the drawing rate of the capstan means and the outflow rate through the nozzles 15 and 16, the rate in turn depending on the temperature and viscosity of the glass melts. The diameter is measured with a thickness meter 19 which controls the drawing rate of the capstan means with the aid of suitable conventional control equipment.
After drawing, the fibre is sensitive to scratches and contamination, and must therefore be provided as quickly as possible with a protective coating. This
OM?I takes place in a receptacle 20 containing suitable liquid coating material, e g curable silicon rubber, which is cured in a suitable, unillustrated heating means after it has adhered to the fibre and when the fibre has passed out from the receptacle 20. A cooling chamber 21, through which the drawn fibre passes is arranged between the drawing nozzle 16 and the receptacle.
The cooling chamber 21 comprises a tube 22 of a porous material with very fine open pores. The material may suitably be a porous metal, e g bronze, produced by sintering or some other method. The material can also be of other types, e g microporous ceramics or plastics. A vessel 23 is arranged round the outside of the tube and provided with a supply pipe 24 connected to a source for compressed gas, preferably dry nitrogen gas. The gas passes through the porous tube 22 and into the space 25 around the fibre. The large number of pores in the tube 22 ensures that the gas flow coming into the space 24 is very uniformly distributed round the fibre and the latter, will not be subjected to any transverse forces. To prevent the gas flow from going upwards and cooling the fibre too early, before it is ready-drawn to the right dimension, the upper opening of the tube 22 is provided with a shield, e g an iris-type aperture, which is solely provided with a fine hole through which the fibre can pass into the tube 22. Due to the cooling, the distance between the drawing nozzle 16 and the receptacle 20 may be shortened considerably. When cooling is carried out with the aid of a dried gas, suitably nitrogen gas,, the risk is further decreased of the fibre absorbing water, which heavily reduces the fibre strength by making its way into the microcracks. By such rapid cooling of the fibre, compression stresses are built into the fibre outer layer so that the tensile strength of the fibre increases in the same way as for hardened glass.
When the fibre passes then through the bath it is cooled such that no curing takes place therein, and the coating will be uniformly distributed around the filament.

Claims

C L A I M S
1 A device in equipment for drawing glass fibres for cooling the fibre after drawing, characterized by a cooling chamber (21) surrounding the fibre (18) and including a tubular container, the inner wall (22) of which comprises a porous material with open pores, the chamber being connected to a source (24) of compressed gas which is caused to pass through the inner wall (22) and out towards the passing fibre (18) in an evenly distributed flow.
2 Device as claimed in claim 1, characterized in that the porous material comprises sintered metal.
3 Device as claimed in claim 1, characterized in that the compressed gas is dry nitrogen gas.
OMPI
PCT/SE1982/000432 1981-12-29 1982-12-20 A device in equipment for drawing glass fibres WO1983002268A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP83500072A JPS58502200A (en) 1981-12-29 1982-12-20 Equipment for glass fiber drawing machine

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8107823A SE433605B (en) 1981-12-29 1981-12-29 DEVICE FOR A GLASS FIBER TREATMENT EQUIPMENT FOR FIBER COOLING
SE8107823-0811229 1981-12-29

Publications (1)

Publication Number Publication Date
WO1983002268A1 true WO1983002268A1 (en) 1983-07-07

Family

ID=20345387

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1982/000432 WO1983002268A1 (en) 1981-12-29 1982-12-20 A device in equipment for drawing glass fibres

Country Status (5)

Country Link
EP (1) EP0097669A1 (en)
JP (1) JPS58502200A (en)
IT (1) IT1153893B (en)
SE (1) SE433605B (en)
WO (1) WO1983002268A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0319374A2 (en) * 1987-12-01 1989-06-07 Alcatel N.V. Inert atmosphere cooler for optical fibers and method of using the same
AU590213B2 (en) * 1984-09-13 1989-11-02 Plasma Optical Fibre B.V. Method of and device for manufacturing an optical fibre having a protective coating
US4966615A (en) * 1987-09-08 1990-10-30 Oy Nokia Ab Apparatus for cooling an optical fiber
US5377491A (en) * 1992-12-11 1995-01-03 Praxair Technology, Inc. Coolant recovery process
US6574972B2 (en) 2001-04-30 2003-06-10 L'air Liquide - Societe' Anonyme A' Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Low temperature heat transfer methods
WO2003080523A2 (en) * 2002-03-25 2003-10-02 L'air Liquide - Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and apparatus for cooling of optical fiber
US6651358B2 (en) 2001-04-30 2003-11-25 American Air Liquide, Inc. Heat transfer fluids and methods of making and using same comprising hydrogen, helium and combinations thereof
US6668582B2 (en) 2001-04-20 2003-12-30 American Air Liquide Apparatus and methods for low pressure cryogenic cooling

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE698179C (en) * 1938-12-30 1940-11-04 Lambert Jansen ze plastic masses, such as B. Glass
GB1559769A (en) * 1977-07-28 1980-01-23 Siemens Ag Drawing of light conducting fibres

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE698179C (en) * 1938-12-30 1940-11-04 Lambert Jansen ze plastic masses, such as B. Glass
GB1559769A (en) * 1977-07-28 1980-01-23 Siemens Ag Drawing of light conducting fibres

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU590213B2 (en) * 1984-09-13 1989-11-02 Plasma Optical Fibre B.V. Method of and device for manufacturing an optical fibre having a protective coating
US4966615A (en) * 1987-09-08 1990-10-30 Oy Nokia Ab Apparatus for cooling an optical fiber
EP0319374A2 (en) * 1987-12-01 1989-06-07 Alcatel N.V. Inert atmosphere cooler for optical fibers and method of using the same
EP0319374A3 (en) * 1987-12-01 1990-09-05 Alcatel N.V. Inert atmosphere cooler for optical fibers and method of using the same
US5377491A (en) * 1992-12-11 1995-01-03 Praxair Technology, Inc. Coolant recovery process
US5452583A (en) * 1992-12-11 1995-09-26 Praxair Technology, Inc. Coolant recovery system
US6668582B2 (en) 2001-04-20 2003-12-30 American Air Liquide Apparatus and methods for low pressure cryogenic cooling
US6574972B2 (en) 2001-04-30 2003-06-10 L'air Liquide - Societe' Anonyme A' Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Low temperature heat transfer methods
US6651358B2 (en) 2001-04-30 2003-11-25 American Air Liquide, Inc. Heat transfer fluids and methods of making and using same comprising hydrogen, helium and combinations thereof
WO2003080523A2 (en) * 2002-03-25 2003-10-02 L'air Liquide - Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and apparatus for cooling of optical fiber
WO2003080523A3 (en) * 2002-03-25 2004-09-30 Air Liquide Method and apparatus for cooling of optical fiber

Also Published As

Publication number Publication date
SE433605B (en) 1984-06-04
EP0097669A1 (en) 1984-01-11
IT8224974A0 (en) 1982-12-24
IT1153893B (en) 1987-01-21
SE8107823L (en) 1983-06-30
JPS58502200A (en) 1983-12-22
IT8224974A1 (en) 1984-06-24

Similar Documents

Publication Publication Date Title
EP0567961B2 (en) Method and apparatus for drawing optical fibers
US4514205A (en) Fiber cooling apparatus
CA1324258C (en) Methods of and apparatus for coating optical fiber and products produced thereby
US4913859A (en) Methods of curing optical fiber coatings
CA1256756A (en) Method and apparatus for coating optical waveguide fiber
EP0733601B2 (en) Method and apparatus for coating fibers
US5408564A (en) Strippable tight buffered optical waveguide
JPH0455138B2 (en)
JPH10114550A (en) Optical fiber, its drawing device, and manufacture of optical fiber
KR100203544B1 (en) Coated optical fiber and method of making the same
US5092264A (en) Apparatus for curing optical fiber coatings
US4374161A (en) Pressure coating of fibers
US4594088A (en) Method and apparatus for making, coating and cooling lightguide fiber
CA1127890A (en) Optical fibres and coatings therefor
EP0034670B1 (en) A glass optical fibre and a method of coating a plastic coated glass fibre with metal
WO1983002268A1 (en) A device in equipment for drawing glass fibres
Blyler et al. Fiber drawing, coating, and jacketing
EP0646552A2 (en) Method of curing dual-coated optical fiber
JPH05213636A (en) Method for coating optical fiber
GB1559769A (en) Drawing of light conducting fibres
US5147432A (en) Methods of and apparatus for coating optical fibers
JP2593693B2 (en) Optical fiber coating method
AU741579B2 (en) Method and apparatus for coating fibers
JPH0380742B2 (en)
CA2026958C (en) Methods of and apparatus for coating optical fibers

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 1983900082

Country of ref document: EP

AK Designated states

Designated state(s): JP US

AL Designated countries for regional patents

Designated state(s): CH DE FR GB

WWP Wipo information: published in national office

Ref document number: 1983900082

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1983900082

Country of ref document: EP