GB2201914A - Optical fibres - Google Patents

Optical fibres Download PDF

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Publication number
GB2201914A
GB2201914A GB08705397A GB8705397A GB2201914A GB 2201914 A GB2201914 A GB 2201914A GB 08705397 A GB08705397 A GB 08705397A GB 8705397 A GB8705397 A GB 8705397A GB 2201914 A GB2201914 A GB 2201914A
Authority
GB
United Kingdom
Prior art keywords
metal
polymer coated
coated optical
optical fibre
optical fibres
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
GB08705397A
Other versions
GB8705397D0 (en
Inventor
Lyndon Reginald Spicer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Original Assignee
STC PLC
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 STC PLC filed Critical STC PLC
Priority to GB08705397A priority Critical patent/GB2201914A/en
Publication of GB8705397D0 publication Critical patent/GB8705397D0/en
Publication of GB2201914A publication Critical patent/GB2201914A/en
Pending legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21CMANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00Extruding metal; Impact extrusion
    • B21C23/22Making metal-coated products; Making products from two or more metals
    • B21C23/24Covering indefinite lengths of metal or non-metal material with a metal coating
    • B21C23/26Applying metal coats to cables, e.g. to insulated electric cables
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401Optical cables
    • G02B6/4415Cables for special applications
    • G02B6/4427Pressure resistant cables, e.g. undersea cables
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401Optical cables
    • G02B6/4429Means specially adapted for strengthening or protecting the cables
    • G02B6/443Protective covering
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4479Manufacturing methods of optical cables
    • G02B6/4486Protective covering
    • G02B6/4488Protective covering using metallic tubes

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Surface Treatment Of Glass Fibres Or Filaments (AREA)

Abstract

A metal or metal alloy sheathing layer 1' on a polymer coated optical fibre 1, particularly for hermetic sealing purposes, is applied by direct extrusion of a low melting point metal (e.g. lead) or metal alloy 3 onto the polymer coated fibre, by means of a ram extruder 5. <IMAGE>

Description

OPTICAL FIBRES This invention relates to optical fibres and in particular to the sheathing of optical fibres.
To protect optical fibres from environmental influences, specifically for the prevention of the ingress of water for undersea applications, it has previously been proposed to encapsulate a number of optical fibres in welded C-section tubes. Similarly for land-based systems use has been made of polyethylene/ aluminium laminated tapes. Both of these methods are difficult manufacturing processes and do not afford protection to individual fibres in their own right.
Optical fibres are generally primary coated following drawing thereof with a plastics material such as a silicone resin, and may be subsequently secondarily coated with another plastics material, such as a polyamide. It has previously been suggested to hermetically seal a primary coated optical fibre by a metal or metal alloy coating applied by drawing the fibre through molten metal or metal alloy. It has also been proposed to hermetically seal freshly drawn optical fibres with other types of coatings such as ceramics, for example silicon nitride.
Optical fibres may be employed in ship-board wiring systems. In such applications the production of obnoxious gases (halogens in particular) from plastics coatings on the fibres during fires should be minimised if not eliminated. Alternative or additional protective coatings are thus desirable on the fibres, which coatings need not be hermetic as is desirable for undersea cable applications.
According to the present invention there is provided a method of sheathing a polymer coated optical fibre including the step of extruding a metal or metal alloy directly over the polymer coated optical fibre.
Embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Fig. 1 illustrates, schematically, a ram extruder for applying a metal sheathing to a polymer coated optical fibre, and Fig. 2 illustrates a cross-section, on a larger scale, through a metal sheathed, polymer coated optical fibre.
The present invention proposes to extrude metal or metal alloy coatings directly onto individual primary or secondary coated optical fibres. For example it is proposed that polymer coated optical fibres be directly sheathed with lead by extrusion thereof. Instead of lead, other low melting point metals or alloys may be similarly employed.
Lead sheathing by extrusion is a technique which was commonly employed for complete cables in the past, it is now proposed, however, to similarly sheath individual polymer coated optical fibres. The extrusion may be performed by a ram extruder, an example of which is illustrated schematically in Fig. 1. A polymer coated optical fibre 1 is fed into a chamber 2 containing the appropriate molten metal or metal alloy 3 and maintained at an appropriate temperature and exits the chamber through an appropriately sized die 4. The metal or alloy 3 is forced out of the chamber 2 by means of ram 5 which is urged into the chamber. The fibre 1 exiting the die 4 comprises an optical core 6, a polymer coating or coatings 7 and an extruded metal sheath 8 (Fig. 2).
The metals and alloys under consideration for use as the extruded sheath should have melting points compatible with the intended use of the optical fibre and the plastics material employed for the polymer coating in order to prevent damage to the latter during metal extrusion and to provide matching of the thermal properties of the polymer and the metal coating so that, for example, elevated temperatures do not cause strain on the optical core. Typically the metals and alloys may have melting points in the range 20-400 C. At the lower end of this range the metal/alloy could be used for undersea environments and those at the top of the range may find application in well-logging where temperatures as high as 3000C are encountered. Examples of suitable low melting point metals and alloys are lead, MCP80 (72 to 980C), Mop150 (138 to 1700cm. Whilst a ram extruder has been referred to above other means of extruding molten low temperature metals and alloys may be employed alternatively, for example hot tip, roller paint process.

Claims (6)

CLAIMS:-
1. A method of sheathing a polymer coated optical fibre including the step of extruding a metal or metal alloy directly over the polymer coated optical fibre.
2. A method as claimed in claim 1 wherein the extruding step is achieved by means of a ram extruder.
3. A method as claimed in claim 1 or claim 2 wherein the metal or metal alloy has a melting point in the range 20 to 4000C.
4. A method as claimed in claim 4 wherein the metal is lead.
5. A method of metal sheathing a polymer coated optical fibre substantially as herein described with reference to the accompanying drawings.
6. A metal or metal alloy sheathed polymer coated optical fibre manufactured by a method according to any one of the preceding claims.
GB08705397A 1987-03-07 1987-03-07 Optical fibres Pending GB2201914A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08705397A GB2201914A (en) 1987-03-07 1987-03-07 Optical fibres

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08705397A GB2201914A (en) 1987-03-07 1987-03-07 Optical fibres

Publications (2)

Publication Number Publication Date
GB8705397D0 GB8705397D0 (en) 1987-04-08
GB2201914A true GB2201914A (en) 1988-09-14

Family

ID=10613531

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08705397A Pending GB2201914A (en) 1987-03-07 1987-03-07 Optical fibres

Country Status (1)

Country Link
GB (1) GB2201914A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003025631A1 (en) * 2001-09-19 2003-03-27 3M Innovative Properties Company Optical and optoelectronic articles
FR2913898A1 (en) * 2007-03-23 2008-09-26 Alcan Rhenalu Sa STRUCTURAL ELEMENT IN ALUMINUM ALLOY INCLUDING AN OPTICAL SENSOR.

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1187088A (en) * 1967-10-04 1970-04-08 Hydraulik Gmbh A Double Ram, Cable Sheathing Extrusion Press.
EP0034670A1 (en) * 1980-02-12 1981-09-02 The Post Office A glass optical fibre and a method of coating a plastic coated glass fibre with metal
GB2177958A (en) * 1985-07-18 1987-02-04 Stc Plc Friction extrusion

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1187088A (en) * 1967-10-04 1970-04-08 Hydraulik Gmbh A Double Ram, Cable Sheathing Extrusion Press.
EP0034670A1 (en) * 1980-02-12 1981-09-02 The Post Office A glass optical fibre and a method of coating a plastic coated glass fibre with metal
GB2177958A (en) * 1985-07-18 1987-02-04 Stc Plc Friction extrusion

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003025631A1 (en) * 2001-09-19 2003-03-27 3M Innovative Properties Company Optical and optoelectronic articles
US7106939B2 (en) 2001-09-19 2006-09-12 3M Innovative Properties Company Optical and optoelectronic articles
FR2913898A1 (en) * 2007-03-23 2008-09-26 Alcan Rhenalu Sa STRUCTURAL ELEMENT IN ALUMINUM ALLOY INCLUDING AN OPTICAL SENSOR.
WO2008129178A2 (en) * 2007-03-23 2008-10-30 Alcan Rhenalu Dressed product comprising an optical sensor, and production method therefor
WO2008129178A3 (en) * 2007-03-23 2008-12-24 Alcan Rhenalu Dressed product comprising an optical sensor, and production method therefor
CN101641167B (en) * 2007-03-23 2011-12-21 法国肯联铝业 Processed product comprising an optical sensor and manufacture method of the processed product
US8693812B2 (en) 2007-03-23 2014-04-08 Constellium France Structrual element made of an aluminum alloy including an optical sensor

Also Published As

Publication number Publication date
GB8705397D0 (en) 1987-04-08

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