GB2172410A - Optical fibre cable containing hydrogen trapping powder - Google Patents

Optical fibre cable containing hydrogen trapping powder Download PDF

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Publication number
GB2172410A
GB2172410A GB08606149A GB8606149A GB2172410A GB 2172410 A GB2172410 A GB 2172410A GB 08606149 A GB08606149 A GB 08606149A GB 8606149 A GB8606149 A GB 8606149A GB 2172410 A GB2172410 A GB 2172410A
Authority
GB
United Kingdom
Prior art keywords
powder
substrate
tape
cable
optical fibre
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.)
Granted
Application number
GB08606149A
Other versions
GB8606149D0 (en
GB2172410B (en
Inventor
Raymond Sydney Ashpole
Norman Charles Fielder
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.)
Telephone Cables Ltd
Original Assignee
Telephone Cables Ltd
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 Telephone Cables Ltd filed Critical Telephone Cables Ltd
Publication of GB8606149D0 publication Critical patent/GB8606149D0/en
Publication of GB2172410A publication Critical patent/GB2172410A/en
Application granted granted Critical
Publication of GB2172410B publication Critical patent/GB2172410B/en
Expired legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401—Optical cables
    • G02B6/4429—Means specially adapted for strengthening or protecting the cables
    • G02B6/44384—Means specially adapted for strengthening or protecting the cables the means comprising water blocking or hydrophobic materials
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401—Optical cables
    • G02B6/4429—Means specially adapted for strengthening or protecting the cables
    • G02B6/44382—Means specially adapted for strengthening or protecting the cables the means comprising hydrogen absorbing materials
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4479—Manufacturing methods of optical cables

Abstract

Optical cables are provided with hydrogen trapping, and optionally water-blocking, powder (11) coated on a substrate tape (1) so as to avoid having loose powder within the cable which can compact and cause loss of freedom of movement of optical fibres (9). The substrate (1) extends longitudinally within a protective cover (10). Optical fibres (9) are shown. <IMAGE>

Description

SPECIFICATION Cables This invention relates to optical fibre cables, that is to say cables incorporating one or more filamentary elements of a light conducting nature within a protective cover and relates also to the manufacture of such cables.
It is known that hydrogen has a deleterious effect on the performance of optical fibres and thus it has been suggested in our co-pending PatentApplication No. 8428102 to use a hydrogen trapping material in such cables, that is to say a material capable of collecting free hydrogen, either by absorption or by chemical or other action, thereby reducing the amount of hydrogen available within the cable which could have a detrimental effect on the optical fibre or fibres.
Such a material may take the form of a powder and in the above-mentioned co-pending application it has been proposed to at least partially fill the interstices between the filamentary elements with such powder. However it has been found that the powder can settle and compact and thus cause a loss of freedom of movement of the elements which is particularly disadvantageous because optical fibres are very fragile.
Accordingly, the invention provides a cable incorporating one or more filamentary elements of a light conducting nature within a protective cover, the cable further including hydrogen trapping powder carried by a substrate extending longitudinally with- in the protective cover.
The hydrogen trapping powder may comprise a material, such as palladium-coated carbon particles, which catalyses the reaction of hydrogen with oxygen to form water. Accordingly the powder in such a case, is preferably mixed with a waterabsorbing or water-blocking substance as mentioned in said co-pending application.
The substrate is preferably a flexible tape made of either paper or plastic such as Mylar or Melinex polyester.
The powder is preferably bonded to the substrate by means of a suitable adhesive, which may be a resin such as acrylic emulsion or a U.V.-cured epoxyacrylate.
In accordance with a further aspect of the invention, there is provided a method of manufacturing a cable incorporating one or more filamentary elements of a light conducting nature the method including the steps of coating a substrate with hydrogen trapping powder, feeding the substrate and one or more said filamentary elements to an extruder head and extruding a protective cover of thermoplastic material around both the substrate and the element or elements.
At least one of the elements may first be enclosed in a separate protective tube before being fed to the extruder head if desired Preferably, the substrate is coated with the powder by first apprying adhesive to the substrate and then dusting the adhesive with the powder. Excess powder may then be scraped off if desired.
The invention will now be more fully described by way of example with reference to the drawing of which Figure 1 shows a diagrammatic form the steps according to the invention required for manufacturing a cable; and Figure 2 shows, in cross-section, one embodiment of a cable made in accordance with the invention.
Turning first to Figure 1, a paper tape 1 is fed from a roll 2 past an applicator 3 which applies acrylic emulsion to one surface of the tape. The tape is then led past a duster 4 which dusts the tape with a hydrogen trapping powder such as palladiumcoated carbon together with a quantity of a waterblocking substance, such as sodium carboxymethyl cellulose also in powder form, which powders stick to the emulsion. A scraper 5 is then used to scrape off excess powder and the tape is then heated by means of a heater 6 so as to cure the emulsion.
The tape is then formed into a tube with the coated side on the inside by passing it through a shaper 7 before it reaches an extruder head 8. As the tape is fed into the shaper 7, optical fibres 9 are also fed in so that they are enclosed within the tube, the fibres being slightly longer than the tube so that they are loose within it.
Finally a plastic protective cover 10 is extruded around the tube by the extruder head 8.
The construction of the cable can best be seen from Figure 2 where three optical fibres of paper tape 1 coated on the inside with hydrogen trapping and water-blocking powders 11 and having an extruded protective cover 10 around it.
The paper tape is conveniently 50ijm thick and has a coating which is typically 1 50-2001lm but could be thicker depending on the dimensions of the tube to be formed. Generally the volume of powder should be between 10-15% of the tube volume.
If a U.V.-cured expoxyacrylate resin is used, there is typically a 50/50 mix of powder/resin by volume.
This type of resin has the advantage of rapid curing and consequently fast production speeds.
It will be appreciated that tapes of other materials can be used providing they are compatible with the adhesive used.
It will further be appreciated that the tapes can easily be introduced into any cable construction whether of the type described above or when the fibres are enclosed within channels in an extrudate, the substrate then being within the channels also, or when the fibres are enclosed within separate tubes stranded together, the substrate then being either within each tube with the fibres or surrounding the stranded tubes or both. Thus the invention is applicable to all types of cable construction and can be used to advantage with all of them.
1. An optical fibre cable as hereinbefore defined including hydrogen trapping powder carried by a substrate extending longitudinally within the protective cover.
2. An optical fibre cable according to Claim 1 wherein the hydrogen trapping powder comprises a
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (14)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Cables This invention relates to optical fibre cables, that is to say cables incorporating one or more filamentary elements of a light conducting nature within a protective cover and relates also to the manufacture of such cables. It is known that hydrogen has a deleterious effect on the performance of optical fibres and thus it has been suggested in our co-pending PatentApplication No. 8428102 to use a hydrogen trapping material in such cables, that is to say a material capable of collecting free hydrogen, either by absorption or by chemical or other action, thereby reducing the amount of hydrogen available within the cable which could have a detrimental effect on the optical fibre or fibres. Such a material may take the form of a powder and in the above-mentioned co-pending application it has been proposed to at least partially fill the interstices between the filamentary elements with such powder. However it has been found that the powder can settle and compact and thus cause a loss of freedom of movement of the elements which is particularly disadvantageous because optical fibres are very fragile. Accordingly, the invention provides a cable incorporating one or more filamentary elements of a light conducting nature within a protective cover, the cable further including hydrogen trapping powder carried by a substrate extending longitudinally with- in the protective cover. The hydrogen trapping powder may comprise a material, such as palladium-coated carbon particles, which catalyses the reaction of hydrogen with oxygen to form water. Accordingly the powder in such a case, is preferably mixed with a waterabsorbing or water-blocking substance as mentioned in said co-pending application. The substrate is preferably a flexible tape made of either paper or plastic such as Mylar or Melinex polyester. The powder is preferably bonded to the substrate by means of a suitable adhesive, which may be a resin such as acrylic emulsion or a U.V.-cured epoxyacrylate. In accordance with a further aspect of the invention, there is provided a method of manufacturing a cable incorporating one or more filamentary elements of a light conducting nature the method including the steps of coating a substrate with hydrogen trapping powder, feeding the substrate and one or more said filamentary elements to an extruder head and extruding a protective cover of thermoplastic material around both the substrate and the element or elements. At least one of the elements may first be enclosed in a separate protective tube before being fed to the extruder head if desired Preferably, the substrate is coated with the powder by first apprying adhesive to the substrate and then dusting the adhesive with the powder. Excess powder may then be scraped off if desired. The invention will now be more fully described by way of example with reference to the drawing of which Figure 1 shows a diagrammatic form the steps according to the invention required for manufacturing a cable; and Figure 2 shows, in cross-section, one embodiment of a cable made in accordance with the invention. Turning first to Figure 1, a paper tape 1 is fed from a roll 2 past an applicator 3 which applies acrylic emulsion to one surface of the tape. The tape is then led past a duster 4 which dusts the tape with a hydrogen trapping powder such as palladiumcoated carbon together with a quantity of a waterblocking substance, such as sodium carboxymethyl cellulose also in powder form, which powders stick to the emulsion. A scraper 5 is then used to scrape off excess powder and the tape is then heated by means of a heater 6 so as to cure the emulsion. The tape is then formed into a tube with the coated side on the inside by passing it through a shaper 7 before it reaches an extruder head 8. As the tape is fed into the shaper 7, optical fibres 9 are also fed in so that they are enclosed within the tube, the fibres being slightly longer than the tube so that they are loose within it. Finally a plastic protective cover 10 is extruded around the tube by the extruder head 8. The construction of the cable can best be seen from Figure 2 where three optical fibres of paper tape 1 coated on the inside with hydrogen trapping and water-blocking powders 11 and having an extruded protective cover 10 around it. The paper tape is conveniently 50ijm thick and has a coating which is typically 1 50-2001lm but could be thicker depending on the dimensions of the tube to be formed. Generally the volume of powder should be between 10-15% of the tube volume. If a U.V.-cured expoxyacrylate resin is used, there is typically a 50/50 mix of powder/resin by volume. This type of resin has the advantage of rapid curing and consequently fast production speeds. It will be appreciated that tapes of other materials can be used providing they are compatible with the adhesive used. It will further be appreciated that the tapes can easily be introduced into any cable construction whether of the type described above or when the fibres are enclosed within channels in an extrudate, the substrate then being within the channels also, or when the fibres are enclosed within separate tubes stranded together, the substrate then being either within each tube with the fibres or surrounding the stranded tubes or both. Thus the invention is applicable to all types of cable construction and can be used to advantage with all of them. CLAIMS
1. An optical fibre cable as hereinbefore defined including hydrogen trapping powder carried by a substrate extending longitudinally within the protective cover.
2. An optical fibre cable according to Claim 1 wherein the hydrogen trapping powder comprises a material which catalyses the reaction of hydrogen with oxygen to form water, and is mixed with a water-absorbing or water-blocking substance.
3. An optical fibre cable according to Claim 1 or 2 wherein the substrate is a flexible tape.
4. An optical fibre cable according to Claim 3 wherein the tape is formed of paper or a plastics material.
5. An optical fibre cable according to any preceding Claim wherein the hydrogen trapping powder is bonded to the substrate by an adhesive.
6. An optical fibre cable according to Claim 5 wherein the adhesive is a synthetic resin.
7. A method of manufacturing an optical fibre cable in accordance with any preceding Claim including the steps of coating a substrate with hydrogen trapping powder, feeding the substrate and one or more said filamentary elements to an extruder head and extruding a protective cover of thermoplastic material around both the substrate and the element or elements.
8. A method according to Claim 7 wherein at least one of the filamentary elements is enclosed in a separate protective tube before being fed to the extruder head.
9. A method according to Claim 7 or 8 wherein the substrate is coated with the powder by first applying an adhesive to the substrate and then dusting the adhesive with the powder.
10. A method according to Claim 9 wherein the adhesive comprises an acrylic emulsion or a U.V.curable epoxyacrylate.
11. A method according to Claim 7, 8,9 or 10 wherein the substrate is in the form of a flexible tape.
12. A method according to Claim 11 wherein the tape is formed of paper or a plastics material.
13. A method of making an optical fibre cable substantially as shown in and as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawing.
14. An optical fibre cable made by a method according to any one of Claims 7 to 13.
GB08606149A 1985-03-13 1986-03-12 Cable containing hydrogen trapping powder Expired GB2172410B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB858506497A GB8506497D0 (en) 1985-03-13 1985-03-13 Cables

Publications (3)

Publication Number Publication Date
GB8606149D0 GB8606149D0 (en) 1986-04-16
GB2172410A true GB2172410A (en) 1986-09-17
GB2172410B GB2172410B (en) 1988-10-26

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Family Applications (2)

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GB858506497A Pending GB8506497D0 (en) 1985-03-13 1985-03-13 Cables
GB08606149A Expired GB2172410B (en) 1985-03-13 1986-03-12 Cable containing hydrogen trapping powder

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB858506497A Pending GB8506497D0 (en) 1985-03-13 1985-03-13 Cables

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GB (2) GB8506497D0 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0314991A1 (en) * 1987-10-30 1989-05-10 AT&T Corp. Water resistant communications cable
US5082719A (en) * 1987-10-30 1992-01-21 At&T Bell Laboratories Water resistant communications cable
US5179619A (en) * 1990-11-13 1993-01-12 Pirelli Cavi S.P.A. Optical fibre element comprising a polyacrylate coating layer reticulated by UV radiation and an H2 -absorbing buffer
US5185841A (en) * 1990-11-29 1993-02-09 Pirelli Cavi S.P.A. Optical fibre element comprising an optical fibre housing constituted by a polyolefin material, and an h2-absorbing buffer
EP0632301A1 (en) * 1993-06-29 1995-01-04 PIRELLI CAVI S.p.A. Hydrogen-absorbing composition for optical fiber cables and optical fiber cables incorporating such compositions
EP0883007A1 (en) * 1997-06-05 1998-12-09 Alcatel Cable having tight tube with at least one optical guide
EP0932063A2 (en) * 1998-01-26 1999-07-28 Alcatel Cable with metallic tight tube comprising at least one optical conductor and an hydrogene absorbing substance
EP1006384A1 (en) * 1998-11-30 2000-06-07 PIRELLI GENERAL plc Optical fibre cable manufacture
US6087000A (en) * 1997-12-18 2000-07-11 Ppg Industries Ohio, Inc. Coated fiber strands, composites and cables including the same and related methods
US6238791B1 (en) 1997-12-18 2001-05-29 Ppg Industries Ohio, Inc. Coated glass fibers, composites and methods related thereto

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6253012B1 (en) 1998-11-12 2001-06-26 Alcatel Cycled fiber lock for cross-functional totally dry optical fiber loose tube cable

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2144559A (en) * 1983-08-05 1985-03-06 Bicc Plc Optical cables
GB2149935A (en) * 1983-11-16 1985-06-19 Telephone Cables Ltd Optical fibre cable
GB2158263A (en) * 1984-04-27 1985-11-06 Pirelli Cavi Spa Optical fibre
GB2158264A (en) * 1984-04-27 1985-11-06 Pirelli Cavi Spa Optical fibre cable
GB2159290A (en) * 1984-05-22 1985-11-27 Stc Plc Cables containing amorphous metals
GB2159978A (en) * 1984-05-23 1985-12-11 Telephone Cables Ltd Optical fibre cables

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2144559A (en) * 1983-08-05 1985-03-06 Bicc Plc Optical cables
GB2144878A (en) * 1983-08-05 1985-03-13 Bicc Plc Optical cables
GB2149935A (en) * 1983-11-16 1985-06-19 Telephone Cables Ltd Optical fibre cable
GB2158263A (en) * 1984-04-27 1985-11-06 Pirelli Cavi Spa Optical fibre
GB2158264A (en) * 1984-04-27 1985-11-06 Pirelli Cavi Spa Optical fibre cable
GB2159290A (en) * 1984-05-22 1985-11-27 Stc Plc Cables containing amorphous metals
GB2159978A (en) * 1984-05-23 1985-12-11 Telephone Cables Ltd Optical fibre cables

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0314991A1 (en) * 1987-10-30 1989-05-10 AT&T Corp. Water resistant communications cable
US4867526A (en) * 1987-10-30 1989-09-19 American Telephone And Telegraph Company, At&T Bell Laboratories Water resistant communications cable
US5082719A (en) * 1987-10-30 1992-01-21 At&T Bell Laboratories Water resistant communications cable
US5179619A (en) * 1990-11-13 1993-01-12 Pirelli Cavi S.P.A. Optical fibre element comprising a polyacrylate coating layer reticulated by UV radiation and an H2 -absorbing buffer
AU646511B2 (en) * 1990-11-13 1994-02-24 Prysmian Cavi E Sistemi Energia S.R.L. Optical fibre element comprising a polyacrylate coating layer reticualated by UV radiation and an hydrogen absorbing buffer
US5185841A (en) * 1990-11-29 1993-02-09 Pirelli Cavi S.P.A. Optical fibre element comprising an optical fibre housing constituted by a polyolefin material, and an h2-absorbing buffer
EP0632301A1 (en) * 1993-06-29 1995-01-04 PIRELLI CAVI S.p.A. Hydrogen-absorbing composition for optical fiber cables and optical fiber cables incorporating such compositions
US5455881A (en) * 1993-06-29 1995-10-03 Pirelli Cavi S.P.A. Hydrogen-absorbing composition for optical fiber cables and optical fiber cables incorporating such composition
US6151434A (en) * 1997-06-05 2000-11-21 Alcatel Sealed tube cable containing at least one optical conductor
FR2764395A1 (en) * 1997-06-05 1998-12-11 Alsthom Cge Alcatel WATERPROOF TUBE CABLE COMPRISING AT LEAST ONE OPTICAL CONDUCTOR
EP0883007A1 (en) * 1997-06-05 1998-12-09 Alcatel Cable having tight tube with at least one optical guide
US6087000A (en) * 1997-12-18 2000-07-11 Ppg Industries Ohio, Inc. Coated fiber strands, composites and cables including the same and related methods
US6238791B1 (en) 1997-12-18 2001-05-29 Ppg Industries Ohio, Inc. Coated glass fibers, composites and methods related thereto
EP0932063A2 (en) * 1998-01-26 1999-07-28 Alcatel Cable with metallic tight tube comprising at least one optical conductor and an hydrogene absorbing substance
FR2774183A1 (en) * 1998-01-26 1999-07-30 Alsthom Cge Alcatel SUBSTANTIALLY WATERPROOF TUBE CABLE HAVING AT LEAST ONE OPTICAL CONDUCTOR AND A HYDROGEN-ABSORBING PRODUCT
EP0932063A3 (en) * 1998-01-26 2000-04-19 Alcatel Cable with metallic tight tube comprising at least one optical conductor and an hydrogene absorbing substance
US6614970B2 (en) 1998-01-26 2003-09-02 Alcatel Cable having a substantially gastight metal tube receiving at least one optical conductor and a hydrogen-absorbent substance
EP1006384A1 (en) * 1998-11-30 2000-06-07 PIRELLI GENERAL plc Optical fibre cable manufacture
US6466720B1 (en) 1998-11-30 2002-10-15 Pirelli General Plc Optical fibre cable manufacture
AU766130B2 (en) * 1998-11-30 2003-10-09 Prysmian Cables & Systems Limited Optical fibre cable manufacture

Also Published As

Publication number Publication date
GB8506497D0 (en) 1985-04-17
GB8606149D0 (en) 1986-04-16
GB2172410B (en) 1988-10-26

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PCNP Patent ceased through non-payment of renewal fee