GB2138429A - Plastics coated glass optical fibres - Google Patents

Plastics coated glass optical fibres Download PDF

Info

Publication number
GB2138429A
GB2138429A GB08307147A GB8307147A GB2138429A GB 2138429 A GB2138429 A GB 2138429A GB 08307147 A GB08307147 A GB 08307147A GB 8307147 A GB8307147 A GB 8307147A GB 2138429 A GB2138429 A GB 2138429A
Authority
GB
United Kingdom
Prior art keywords
temperature
extrudate
polymeric material
crystallisation
fluid
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
GB08307147A
Other versions
GB8307147D0 (en
GB2138429B (en
Inventor
Peter George Hale
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
Standard Telephone and Cables 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 Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB08307147A priority Critical patent/GB2138429B/en
Publication of GB8307147D0 publication Critical patent/GB8307147D0/en
Priority to NZ207328A priority patent/NZ207328A/en
Priority to AU25388/84A priority patent/AU2538884A/en
Publication of GB2138429A publication Critical patent/GB2138429A/en
Application granted granted Critical
Publication of GB2138429B publication Critical patent/GB2138429B/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/007—After-treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/18—Processes for applying liquids or other fluent materials performed by dipping
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/15—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor incorporating preformed parts or layers, e.g. extrusion moulding around inserts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/885—External treatment, e.g. by using air rings for cooling tubular films
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/919—Thermal treatment of the stream of extruded material, e.g. cooling using a bath, e.g. extruding into an open bath to coagulate or cool the material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D11/00—Producing optical elements, e.g. lenses or prisms
    • B29D11/00663—Production of light guides
    • 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
    • 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
    • G02B6/4402—Optical cables with one single optical waveguide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2256/00—Wires or fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/02—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
    • B05D3/0218—Pretreatment, e.g. heating the substrate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/02—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
    • B05D3/0254—After-treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/02—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
    • B05D3/0254—After-treatment
    • B05D3/0263—After-treatment with IR heaters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/20—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to wires
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/05—Filamentary, e.g. strands

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Optics & Photonics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Physics & Mathematics (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Materials Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Ophthalmology & Optometry (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
  • Surface Treatment Of Glass Fibres Or Filaments (AREA)

Abstract

Dimensional stability problems are associated with the quench cooling of optical fibres provided with a secondary extrudate coating of crystallisable polymeric material when such coatings are subsequently thermally cycled above their glass transisition temperature. These are avoided by forced cooling with fluid within the temperature band of peak crystallisation rate until crystallisation has proceeded to substantially the maximum achievable value.

Description

SPECIFICATION Plastics coated glass optical fibres This invention relates to the manufacture of plastics coated glass optical fibres.
When glass optical fibre is made it is conventional to provide the freshly drawn fibre surface, typically but not necessarily a silica surface, with a primary plastics coating on-line with the fibre drawing operation in order to give a measure of protection for the glass surface against degradation by atmospheric attack. This coating is typically no more than about 50 microns thick, and usually a second thicker coating, a secondary coating, is applied at a later stage to give a more robust package. This secondary coating is typically provided by extrusion. Each of these coatings is a tight coating with substantially no voids between it and the material it envelopes, and hence, if it is subject to shrinkage in the axial direction over an appreciable length, then this shrinkage is transmitted to the fibre.
When a thermo-plastics sheath of crystallisable polymeric material is applied by extrusion to a metal wire to provide electrical insulation it is quite common to quench cool the extrudate by passing it through a water trough immediately after it leaves the extruder. The same practice has been employed for applying plastics coatings to optical fibres, but in this instance it has been found that quench cooling gives rise to subsequent problems as the plastics material later attempts to anneal into a state more closely approximating to an 'equilibrium' state.
Quench cooling produces a relatively low density product in which the amount of crystallisation is well below the maximum value that is achievable for that material. Subsequent thermal excursions above the glass transition temperature are liable to produce a significant increase in the amount of crystallisation, and this is manifest by an increase in the axial (and radial) compression of the fibre which, if uncontrolled, can lead to a dramatic increase in attenuation at low temperatures due to fibre buckling. This occurs for instance when a quench cooled nylon secondary coating is subject to being temporarily heated to 70 to 80", for example, in the course of extruding a cable sheath round an assembly of packaged fibres.
It has been found that, provided the line speed is not too fast, this problem can be greatly reduced by using still air at ambient temperature to cool the secondary coating extrudate as it leaves the extruder. This air cooling has to be over a long enough distance for the extrudate to pass right through the temperature band of peak crystallisation rate before it is subject to any fiercer cooling. By way of example it has been demonstrated that, with a line speed of 40 m/min., 0.85 mm diameter nylon coating can be satisfactorily annealed with cooling in static air at ambient temperature for a duration of seven and a half seconds. This corresponds to an air gap of 5 meters.However, as higher line speeds are attempted the requisite lengthening of the air gap to preserve the same duration of air cool becomes impractical, primarily because of the attendant requirement to increase the line tension to avoid excessive droop of the line catenary. In this context it is to be noted that the line tension dictates the axial strain induced in the fibre when the package is at room temperature, and it is desirable to be able to control this parameter to suit the particular requirements determined by the environmental conditions in which the package is going to be cabled, installed, and used.
According to the present invention there is provided a method of providing an extruded plastics tight coating of crystallisable polymeric material around a glass fibre, wherein on emerging from extruder the extrudate is annealed in a forced flow of fluid maintained at a temperature which is in excess of the glass transition temperature of the polymeric material and is in the vicinity of the temperature at which the crystallisation growth rate is at it peak value, and in which flow the extrudate is maintained until it is crystallised to substantially the fullest extent achievable.
The forced flow annealing, provided for instance by passing the extrudate through a thermostatically controlled recirculating oil bath, or by directing hot air jets against its surface, is capable of providing more rapid cooling of the extrudate to the temperature band of maximum crystallisation rate and then holding the temperature within this band until crystallisation is effectively complete. In this way full crystallisation is capable of being achieved in a shorter time, thus allowing a greater line speed for a given length of annealer. After sufficient crystallisation has been achieved, further cooling to below the glass transition temperature may be effected as quickly as is found convenient. This may be for instance by forced air cooling with air at room temperature, or by quench cooling with cold water.It may also be noted that if the cooling fluid used to promote rapid crystallisation is a liquid, an effect of its greater density in comparison with air will be to provide an increased measure of buoyancy which is helpful in reducing the minimum required tension in the line. If the fluid is a gas additional buoyancy can alternatively be achieved by directing gas flow upwardly around the extrudate.
Typically the temperature band of operation is about i 1 0 C from the temperature of peak crystallisation rate, with the limits of the band being at about 30% of the peak value or preferably at least 50% of that value. By the time the crystallisation has proceeded to 90% of the maximum achievable value for that material its mechanical properties are substantially those of the fully crystallised material to the extent that subsequent short duration temperature excursions above the glass transitions temperature do not cause any significant shrinkage.
For a 0.85 mm diameter secondary coating of nylon 12 satisfactory annealing is preferably performed at a temperature of about 1 50 C. A heated silicone oil may be used for this purpose, or alternatively heated air directed against the underside of, or around, the coated fibre for instance from jets disposed on either side. The crystallisation is substantially complete after an annealing period at this temperature of about 5 seconds.

Claims (5)

1. A method of providing an extruding plastics tight coating of crystallisable polymeric material around a glass fibre, wherein on emerging from the extruder the extrudate is annealed in a fluid maintained at a tempera- ture which is in excess of the glass transition temperature of the polymeric material and is in the vicinity of the temperature at which the crystallisation growth rate is at it peak value, and in which flow the extrudate is maintained until it is crystallised to substantially the fullest extent achievable with that material.
2. A method of providing an extruded plastics tight coating of crystallisable polymeric material around a glass fibre, wherein on emerging from the extruder the extrudate is annealed in a forced flow of fluid maintained at a temperature within the band over which the crystallisation growth rate is at least 30% of its peak value, and in which flow the extrudate is maintained until it is crystallised to at least 90% of the maximum crystallinity achievable with that material.
3. A method as claimed in claim 1 or 2, wherein the annealing fluid is a liquid.
4. A method as claimed in claim 1 or 2, wherein the annealing fluid is a gas.
5. A glass optical fibre provided with an extruded plastics coating of crystallisable polymeric material by the method claimed in any preceding claim.
GB08307147A 1983-03-15 1983-03-15 Plastics coated glass optical fibres Expired GB2138429B (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB08307147A GB2138429B (en) 1983-03-15 1983-03-15 Plastics coated glass optical fibres
NZ207328A NZ207328A (en) 1983-03-15 1984-03-01 Extruding plastics coating onto optical fibres
AU25388/84A AU2538884A (en) 1983-03-15 1984-03-09 Plastic coating of optical fibres

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08307147A GB2138429B (en) 1983-03-15 1983-03-15 Plastics coated glass optical fibres

Publications (3)

Publication Number Publication Date
GB8307147D0 GB8307147D0 (en) 1983-04-20
GB2138429A true GB2138429A (en) 1984-10-24
GB2138429B GB2138429B (en) 1987-07-15

Family

ID=10539627

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08307147A Expired GB2138429B (en) 1983-03-15 1983-03-15 Plastics coated glass optical fibres

Country Status (3)

Country Link
AU (1) AU2538884A (en)
GB (1) GB2138429B (en)
NZ (1) NZ207328A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2167703A (en) * 1984-12-01 1986-06-04 Stc Plc Cooling extrusion coated optical cables
EP0383980A1 (en) * 1987-08-31 1990-08-29 Sekisui Kagaku Kogyo Kabushiki Kaisha A method for coating a metal substrate by the use of a resin composition
EP0857313A1 (en) * 1996-07-31 1998-08-12 Corning Incorporated Dispersion compensating single mode waveguide
US6349163B1 (en) 1996-07-31 2002-02-19 Corning Incorporated Dispersion compensating single mode waveguide

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL191704C (en) * 1983-05-16 1996-04-02 Rodiac Intercessor Ltd Scraper for a conveyor belt.

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB689252A (en) * 1950-07-06 1953-03-25 British Insulated Callenders Improvements in the extrusion of coverings of thermo-plastic material around wire
GB1196290A (en) * 1966-12-22 1970-06-24 Algemene Kunstzijde Unie Nv Shaped Articles of Polyethylene Terephthalate, and a process for their manufacture
GB1582021A (en) * 1976-04-22 1980-12-31 Western Electric Co Extruding material around an elongate core
GB1599106A (en) * 1978-04-26 1981-09-30 Bicc Ltd Manufacture of insulated wires and cables

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB689252A (en) * 1950-07-06 1953-03-25 British Insulated Callenders Improvements in the extrusion of coverings of thermo-plastic material around wire
GB1196290A (en) * 1966-12-22 1970-06-24 Algemene Kunstzijde Unie Nv Shaped Articles of Polyethylene Terephthalate, and a process for their manufacture
GB1582021A (en) * 1976-04-22 1980-12-31 Western Electric Co Extruding material around an elongate core
GB1599106A (en) * 1978-04-26 1981-09-30 Bicc Ltd Manufacture of insulated wires and cables

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2167703A (en) * 1984-12-01 1986-06-04 Stc Plc Cooling extrusion coated optical cables
EP0383980A1 (en) * 1987-08-31 1990-08-29 Sekisui Kagaku Kogyo Kabushiki Kaisha A method for coating a metal substrate by the use of a resin composition
US4965102A (en) * 1987-08-31 1990-10-23 Sekisui Kagaku Kogyo Kabushiki Kaisha Method for coating a metal substrate by the use of a resin composition
EP0857313A1 (en) * 1996-07-31 1998-08-12 Corning Incorporated Dispersion compensating single mode waveguide
EP0857313A4 (en) * 1996-07-31 2000-04-12 Corning Inc Dispersion compensating single mode waveguide
US6349163B1 (en) 1996-07-31 2002-02-19 Corning Incorporated Dispersion compensating single mode waveguide

Also Published As

Publication number Publication date
GB8307147D0 (en) 1983-04-20
NZ207328A (en) 1986-07-11
AU2538884A (en) 1984-09-20
GB2138429B (en) 1987-07-15

Similar Documents

Publication Publication Date Title
CA1179218A (en) Process for producing a glass fiber for light transmission
US5944865A (en) Apparatus for fabricating an optical fiber coated with metal and method therefor
US4906066A (en) Optical fibre cable utilizing thermotropic liquid crystal polymer and method of making same
US4704307A (en) Method of and arrangement for coating a fibre
US20010006262A1 (en) Method of cooling an optical fiber while it is being drawn
US5444808A (en) Plastics packaged optical fibre and method of making same
GB2138429A (en) Plastics coated glass optical fibres
RU2128630C1 (en) Method of drawing optical fiber and device for its embodiment
US4351659A (en) Method for manufacture of graded index optical fibres
US4803027A (en) Process for the production of biaxially stretched films and apparatus for implementation of the process
CA1276760C (en) Process for producing oriented polyolefin films with enhanced physical properties
KR100271880B1 (en) Heat treatment of cable
US6870994B2 (en) Optical fiber cord, manufacturing method thereof, and manufacturing apparatus thereof
US4671905A (en) Method of a forming a secondary coating on an optical fiber
US4493747A (en) Method for insulating conductors with a crystalline plastic material
EP0049156B1 (en) Method of and arrangement for manufacturing an optical cable element
GB2079970A (en) Improvements in or relating to optical cable elements
EP0065415A1 (en) Polymeric film casting and apparatus therefor
JPH0438226B2 (en)
Wagatsuma et al. Slip mechanism in optical fiber coating with open-cup applicators
Yamamoto Jacketing of Optical Fibers with Ordered Thermotropic Liquid Crystal Polyesters
JP2746628B2 (en) Method of manufacturing optical fiber coated with fluororesin
JP2801415B2 (en) Optical fiber manufacturing method
CA1219420A (en) Method and apparatus for manufacturing magnet wire
DK151991B (en) CABLE CIRCUIT AND PLASTIC COVER COVER

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee