CA1177614A - Method and apparatus for use in coating an elongate filament - Google Patents
Method and apparatus for use in coating an elongate filamentInfo
- Publication number
- CA1177614A CA1177614A CA000441786A CA441786A CA1177614A CA 1177614 A CA1177614 A CA 1177614A CA 000441786 A CA000441786 A CA 000441786A CA 441786 A CA441786 A CA 441786A CA 1177614 A CA1177614 A CA 1177614A
- Authority
- CA
- Canada
- Prior art keywords
- fluid
- passage
- fiber
- zone
- cup
- 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.)
- Expired
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
- 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
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C3/00—Apparatus in which the work is brought into contact with a bulk quantity of liquid or other fluent material
- B05C3/02—Apparatus in which the work is brought into contact with a bulk quantity of liquid or other fluent material the work being immersed in the liquid or other fluent material
- B05C3/12—Apparatus in which the work is brought into contact with a bulk quantity of liquid or other fluent material the work being immersed in the liquid or other fluent material for treating work of indefinite length
-
- 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
- B29D11/00865—Applying coatings; tinting; colouring
- B29D11/00875—Applying coatings; tinting; colouring on 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
- C03C25/12—General methods of coating; Devices therefor
- C03C25/18—Extrusion
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Ophthalmology & Optometry (AREA)
- Health & Medical Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Surface Treatment Of Glass Fibres Or Filaments (AREA)
Abstract
METHOD AND APPARATUS FOR USE IN COATING AN ELONGATE FILAMENT
Abstract of the Disclosure To uniformly coat a fiber, it is fed downwards through a passage filled with a coating fluid. The passage has a downwardly tapering lower zone into which fluid is directed from outside the passage uniformly, radially inwardly and downwardly. The fluid directed into the lower zone suppresses turbulence within the fluid at a bottom outlet aperture within the lower zone. The passage at an upper zone is large enough to allow bubbles to float to the surface of the fluid. The arrangement prevents turbulence and air bubbles from causing thinly coated fiber regions which might adversely affect the fiber integrity. The passage is defined by two relatively moveable bodies so that the rate at which the coating fluid is injected into the lower zone can be varied.
- i -
Abstract of the Disclosure To uniformly coat a fiber, it is fed downwards through a passage filled with a coating fluid. The passage has a downwardly tapering lower zone into which fluid is directed from outside the passage uniformly, radially inwardly and downwardly. The fluid directed into the lower zone suppresses turbulence within the fluid at a bottom outlet aperture within the lower zone. The passage at an upper zone is large enough to allow bubbles to float to the surface of the fluid. The arrangement prevents turbulence and air bubbles from causing thinly coated fiber regions which might adversely affect the fiber integrity. The passage is defined by two relatively moveable bodies so that the rate at which the coating fluid is injected into the lower zone can be varied.
- i -
Description
,r~
This invention relates to a method and apparatus for use ln coating an elongate filament and particularly to such a method and apparatus for coating an optical waveguide drawn directly from preceding waveguide manufacturing equipment.
Dielectric optical waveguides should have sufficient strength and integrity that they are not damaged by operations occurring subsequent to fiber drawing such as fiber take-up onto reels, fiber characterization, fiber cabling and cable installation.
The waveguide integrity can be markedly reduced if the various handling processes introduce surface defects into the fiber.
Plastic coatings can provide good protection against surface defects resulting from abrasion and other mechanical stresses.
Such coatings can also reduce microbending loss and cross talk between fibers. The coating should be sufficiently thick and resilient to protect the underlying fiber in spite of any bending of the fiber. The coating should also be mechanically strippable, non-hydroscopic, concentric with respect to the fiber and uniform thickness. Suitable materials for coating optical fibers are silicone, epoxy-acrylates, tetrafluorethylene, ethylene-vinyl-acetate copolymer, perfluorinated ethylenepropylene and perfluoro-vinyl-methyl ether. A variety of coating methods may be used for this purpose a common techinque being shown in U.S. patent 3,980,390 (Yamamoto et al) in which filament immediately after it has been drawn is passed into a reservoir of the suitable coating material and out of the base of the reservoir through a nipple or coating die.
In order to obtain higher fiber drawing speeds, tapered dies have been proposed, the tapered dies tending to give a more concentric coating than the simple apertured reservoir known - .~}
previously. Tapered bnre arran~Jements are described for example in U.S. Defensive publlcation number T963002 (Albarlno et al).
Even with these tapered dies there is a problem of turbulence resulting when a fiber passes rapidly through a chamber in which viscous coating fluid is substantially static. In the contact zone some of the fluid must be accelerated to the fiber speed relative to the rest of the fluid in the chamber. If the turbulence persists to the die exit aperture, it can result both in a variation in coating thickness and in the introduction of air bubbles into the coating so weakening the jacketed fiber.
One attempt to solve the problem of turbulence is described in U.S. patent 4,294,190 (Ohls). As described in this patent specification a die and reservoir are configured such that the fiber passes through a tapered die full of coating fluid. Additional fluid is supplied from a reservoir not into the top of the die where the fiber enters the fluid, but some way down the tapered die through a series of radial ports extending through the die and providing fluid communication between the reservoir and the tapered bore. The provision of individual fixed aperture ports does not permit easy adjustment of the equipment to compensate both for changing coating fluid viscosity or change in the speed at which fiber is drawn through the die. Consequently, if the coating fluid viscosity increases or the fiber draw speed is increased, the fiber may be imperfectly coated. In addition, eccentricity of the fiber within the coating can result from using several discrete inlet ports especially if they are not exactly radially symmetric.
:
An alternative arrangement ls now proposed whlch overcomes the problems of fiber coating eccentricity and turbulence discussed previously. In addition, the arrangement can be easily adjusted to take account of changes both in fiber drawing speed and coating fluid viscosity.
According to one aspect of the invention, there is provided a fiber coating mechanism comprising means defining a passage, the passage having an upper vertical zone of substantially uniform cross-sectional area communicating at a lower end thereof with a downwardly tapering lower zone, the lower zone substantially centro-symmetric about a vertical axis, the lower zone at an upper end thereof greater in cross-sectional area than the upper zone and at a lower end thereof less in cross-sectional area than the upper zone, the lower zone having an annular fluid inlet zone at an outer extremity thereof at said upper end and an exit aperture at the lower end thereof, the exit aperture vertically aligned with a central axis of the upper zone, means for feeding fiber vertically downward through the passage, and means for feeding fluid into the passage - through the inlet aperture to fill the lower zone and at least partially to fill the upper zone.
The passage can be defined by a regulating valve and a cup, the upper zone defined by a bore through a stem of the valve the lower zone defined by a lower part of the cup and the annular aperture defined by an inner wall of the cup and an outer surface of the valve stem.
The cup can have a nipple in a base thereof, the nipple having a tapered coating chamber therein. The cup can have a tapered fluid storage chamber above the annular aperture.
The valve stem can be vertlcally reclprocal whereby the size of the annular gap can be adjusted, The valve stem can screw engage a bore through a lid for the cup.
The cup preferably has an inner wall which is steep at the top of the cup and becomes shallower towards the annular aperture. The nipple preferably has a conical inner surface. The fluid coatiny mechanism can further include means for supplying fluid to the storage chamber to a level whereby to set the pressure of fluid at the annular aperture. The nipple can be screw threaded into the base of the cup.
According to another aspect of the invention there is provided a method of coating a fiber comprising feeding the fiber vertically downward through a passage filled with coating fluid, the passage having an upper zone within which air bubbles and turbulence are inevitably introduced into the fluid the upper zone being of sufficient length and cross-sectional area to permit the introduced bubbles to float upwardly therethrough, the passage further having a downwardly tapering lower zone, the method further comprising directing fluid uniformly radially inwardly and downwardly into the lower zone to suppress the introduced turbulence at an exit aperture at a lower end of the passage.
An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:-Figure 1 is a sectional view through a coating mechanismaccording to the invention; and Figure 2 is a sectional view to a larger scale of a part of the Figure 1 mechanism.
, ~ :
.
.
' 117761~
Referring ln detail to Figure 1, there is shown d coating mechanism having a cup lO, a nipple 12 and a valve 14. A
fiber 16 is drawn vertically downwards through a bore 18 in the valve 14 and out through an aperture 20 at the lower tip of the nipple.
Within the nipple 12 the fiber 16 is coated with a protective fluid 22. The cup 10 has an inner surface 24 which is steep at the top end of the cup but which becomes shallower towards an aperture 26 within the base of the cup. Essentially the inner surface of the cup is paraboloid. The nipple 12 which is of stainless steel composition, screw engages within a recess 32 at the base of the cup 10. On a lip 28 of the cup is mounted a stem support 30 through which extends an internally threaded bore. The valve stem is externally threaded and engages within the bore.
As shown to a larger scale in Figure 2, the nipple 12 has a conical inner surface 34 and the valve stem has a convex lower surface 36. An annular gap or restriction 38 is defined by an angular projection at the junction of the cup 10 and the nipple 12 which opposes the outer convex surface 36 of the valve 14.
As shown in Figure 2, viscous coating fluid 22 stored within the cup 10 is forced by gravity through the annular gap 38 into a conical chamber 40 defined by the nipple. The level of fluid within the cup is sufficiently high that the fluid extends somewhat up the bore in the valve stem. The shape of the valve 14, the cup 10 and nipple 12 at the gap 38 determine that the fluid 22 is directed radially symmetrically into the chamber 40.
As illustrated in Figure 2 turbulence and air bubbles are introduced into the fluid 22 by the passage of fi'ber 16 into and through it. By ensuring a sufficient fluid height and a relatively , ~
,. , , ' ~ 1177614 wide bore 18 within the valve stem 14, air bubbles entralned by the fiber are permitted to float freely up the bore to the surface of the coating fluid within the stem. However, with such a wide bore 18, turbulence tends to be transmitted down through the passage. The persistence of turbulence is discouraged by the flow of fluid through the annular gap 38. As shown in Figure 2 the relatively large turbulent eddies emitted from the bottom of the valve stem 14 are gradually suppressed within the nipple tapered chamber 40.
Consequently immediately above the exit aperture 20 of the nipple, substantially lamellar flow is restored. Thus as the coating fluid exits the die in contact with the fiber 16, it is devoid both of turbulent eddies and air bubbles and thus uniformly coats the fiber.
The pressure and viscosity of fluid 22 within the cup 10 and the width of the annular gap 38 determine the rate at which coating fluid enters the conical chamber 40 within the nipple 12.
That rate is set equal to the rate at which fluid exits the nipple 12 with the chamber 40 filled. If the rate at which fiber is being pulled through the coating mechanism is raised and consequently a greater flow of coating fluid into the coating chamber 40 is desired then the annular gap is increased by rotating the valve 14 to lift it through the stem support 30 and increase the size of the annular gap.
If the viscosity of the coating fluid changes then compensation can be made either by increasing the height of fluid 22 within the storage reservoir or by changing the size of the annular gap 38, or both. These two operating parameters can be tuned for the desired fluid dynamic activity within the coating chamber 40.
~ 6 " ;' ~ ~ ` -,~` -~ 1177614 After coatlng with flu~d, tne fluid coating is cured for example by heat in the case of a silicone or by ultra-violet light if using acrylates or other ultra-violet curing material.
Although the invention has been described in terms of applying a plastic coating to glass clad optical fiber to protect the fiber, the coating method described can also be used in other circumstances where it is desired to apply a uniform coating to a solid fiber, for example, for applying lower refractive index plastic cladding directly to a fused silica core.
....
-: ~
This invention relates to a method and apparatus for use ln coating an elongate filament and particularly to such a method and apparatus for coating an optical waveguide drawn directly from preceding waveguide manufacturing equipment.
Dielectric optical waveguides should have sufficient strength and integrity that they are not damaged by operations occurring subsequent to fiber drawing such as fiber take-up onto reels, fiber characterization, fiber cabling and cable installation.
The waveguide integrity can be markedly reduced if the various handling processes introduce surface defects into the fiber.
Plastic coatings can provide good protection against surface defects resulting from abrasion and other mechanical stresses.
Such coatings can also reduce microbending loss and cross talk between fibers. The coating should be sufficiently thick and resilient to protect the underlying fiber in spite of any bending of the fiber. The coating should also be mechanically strippable, non-hydroscopic, concentric with respect to the fiber and uniform thickness. Suitable materials for coating optical fibers are silicone, epoxy-acrylates, tetrafluorethylene, ethylene-vinyl-acetate copolymer, perfluorinated ethylenepropylene and perfluoro-vinyl-methyl ether. A variety of coating methods may be used for this purpose a common techinque being shown in U.S. patent 3,980,390 (Yamamoto et al) in which filament immediately after it has been drawn is passed into a reservoir of the suitable coating material and out of the base of the reservoir through a nipple or coating die.
In order to obtain higher fiber drawing speeds, tapered dies have been proposed, the tapered dies tending to give a more concentric coating than the simple apertured reservoir known - .~}
previously. Tapered bnre arran~Jements are described for example in U.S. Defensive publlcation number T963002 (Albarlno et al).
Even with these tapered dies there is a problem of turbulence resulting when a fiber passes rapidly through a chamber in which viscous coating fluid is substantially static. In the contact zone some of the fluid must be accelerated to the fiber speed relative to the rest of the fluid in the chamber. If the turbulence persists to the die exit aperture, it can result both in a variation in coating thickness and in the introduction of air bubbles into the coating so weakening the jacketed fiber.
One attempt to solve the problem of turbulence is described in U.S. patent 4,294,190 (Ohls). As described in this patent specification a die and reservoir are configured such that the fiber passes through a tapered die full of coating fluid. Additional fluid is supplied from a reservoir not into the top of the die where the fiber enters the fluid, but some way down the tapered die through a series of radial ports extending through the die and providing fluid communication between the reservoir and the tapered bore. The provision of individual fixed aperture ports does not permit easy adjustment of the equipment to compensate both for changing coating fluid viscosity or change in the speed at which fiber is drawn through the die. Consequently, if the coating fluid viscosity increases or the fiber draw speed is increased, the fiber may be imperfectly coated. In addition, eccentricity of the fiber within the coating can result from using several discrete inlet ports especially if they are not exactly radially symmetric.
:
An alternative arrangement ls now proposed whlch overcomes the problems of fiber coating eccentricity and turbulence discussed previously. In addition, the arrangement can be easily adjusted to take account of changes both in fiber drawing speed and coating fluid viscosity.
According to one aspect of the invention, there is provided a fiber coating mechanism comprising means defining a passage, the passage having an upper vertical zone of substantially uniform cross-sectional area communicating at a lower end thereof with a downwardly tapering lower zone, the lower zone substantially centro-symmetric about a vertical axis, the lower zone at an upper end thereof greater in cross-sectional area than the upper zone and at a lower end thereof less in cross-sectional area than the upper zone, the lower zone having an annular fluid inlet zone at an outer extremity thereof at said upper end and an exit aperture at the lower end thereof, the exit aperture vertically aligned with a central axis of the upper zone, means for feeding fiber vertically downward through the passage, and means for feeding fluid into the passage - through the inlet aperture to fill the lower zone and at least partially to fill the upper zone.
The passage can be defined by a regulating valve and a cup, the upper zone defined by a bore through a stem of the valve the lower zone defined by a lower part of the cup and the annular aperture defined by an inner wall of the cup and an outer surface of the valve stem.
The cup can have a nipple in a base thereof, the nipple having a tapered coating chamber therein. The cup can have a tapered fluid storage chamber above the annular aperture.
The valve stem can be vertlcally reclprocal whereby the size of the annular gap can be adjusted, The valve stem can screw engage a bore through a lid for the cup.
The cup preferably has an inner wall which is steep at the top of the cup and becomes shallower towards the annular aperture. The nipple preferably has a conical inner surface. The fluid coatiny mechanism can further include means for supplying fluid to the storage chamber to a level whereby to set the pressure of fluid at the annular aperture. The nipple can be screw threaded into the base of the cup.
According to another aspect of the invention there is provided a method of coating a fiber comprising feeding the fiber vertically downward through a passage filled with coating fluid, the passage having an upper zone within which air bubbles and turbulence are inevitably introduced into the fluid the upper zone being of sufficient length and cross-sectional area to permit the introduced bubbles to float upwardly therethrough, the passage further having a downwardly tapering lower zone, the method further comprising directing fluid uniformly radially inwardly and downwardly into the lower zone to suppress the introduced turbulence at an exit aperture at a lower end of the passage.
An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:-Figure 1 is a sectional view through a coating mechanismaccording to the invention; and Figure 2 is a sectional view to a larger scale of a part of the Figure 1 mechanism.
, ~ :
.
.
' 117761~
Referring ln detail to Figure 1, there is shown d coating mechanism having a cup lO, a nipple 12 and a valve 14. A
fiber 16 is drawn vertically downwards through a bore 18 in the valve 14 and out through an aperture 20 at the lower tip of the nipple.
Within the nipple 12 the fiber 16 is coated with a protective fluid 22. The cup 10 has an inner surface 24 which is steep at the top end of the cup but which becomes shallower towards an aperture 26 within the base of the cup. Essentially the inner surface of the cup is paraboloid. The nipple 12 which is of stainless steel composition, screw engages within a recess 32 at the base of the cup 10. On a lip 28 of the cup is mounted a stem support 30 through which extends an internally threaded bore. The valve stem is externally threaded and engages within the bore.
As shown to a larger scale in Figure 2, the nipple 12 has a conical inner surface 34 and the valve stem has a convex lower surface 36. An annular gap or restriction 38 is defined by an angular projection at the junction of the cup 10 and the nipple 12 which opposes the outer convex surface 36 of the valve 14.
As shown in Figure 2, viscous coating fluid 22 stored within the cup 10 is forced by gravity through the annular gap 38 into a conical chamber 40 defined by the nipple. The level of fluid within the cup is sufficiently high that the fluid extends somewhat up the bore in the valve stem. The shape of the valve 14, the cup 10 and nipple 12 at the gap 38 determine that the fluid 22 is directed radially symmetrically into the chamber 40.
As illustrated in Figure 2 turbulence and air bubbles are introduced into the fluid 22 by the passage of fi'ber 16 into and through it. By ensuring a sufficient fluid height and a relatively , ~
,. , , ' ~ 1177614 wide bore 18 within the valve stem 14, air bubbles entralned by the fiber are permitted to float freely up the bore to the surface of the coating fluid within the stem. However, with such a wide bore 18, turbulence tends to be transmitted down through the passage. The persistence of turbulence is discouraged by the flow of fluid through the annular gap 38. As shown in Figure 2 the relatively large turbulent eddies emitted from the bottom of the valve stem 14 are gradually suppressed within the nipple tapered chamber 40.
Consequently immediately above the exit aperture 20 of the nipple, substantially lamellar flow is restored. Thus as the coating fluid exits the die in contact with the fiber 16, it is devoid both of turbulent eddies and air bubbles and thus uniformly coats the fiber.
The pressure and viscosity of fluid 22 within the cup 10 and the width of the annular gap 38 determine the rate at which coating fluid enters the conical chamber 40 within the nipple 12.
That rate is set equal to the rate at which fluid exits the nipple 12 with the chamber 40 filled. If the rate at which fiber is being pulled through the coating mechanism is raised and consequently a greater flow of coating fluid into the coating chamber 40 is desired then the annular gap is increased by rotating the valve 14 to lift it through the stem support 30 and increase the size of the annular gap.
If the viscosity of the coating fluid changes then compensation can be made either by increasing the height of fluid 22 within the storage reservoir or by changing the size of the annular gap 38, or both. These two operating parameters can be tuned for the desired fluid dynamic activity within the coating chamber 40.
~ 6 " ;' ~ ~ ` -,~` -~ 1177614 After coatlng with flu~d, tne fluid coating is cured for example by heat in the case of a silicone or by ultra-violet light if using acrylates or other ultra-violet curing material.
Although the invention has been described in terms of applying a plastic coating to glass clad optical fiber to protect the fiber, the coating method described can also be used in other circumstances where it is desired to apply a uniform coating to a solid fiber, for example, for applying lower refractive index plastic cladding directly to a fused silica core.
....
-: ~
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A fiber coating mechanism comprising means defining a passage, the passage having an upper vertical zone of substantially uniform cross-sectional area communicating at a lower end thereof with a downwardly tapering lower zone, the lower zone substantially centro-symmetric about a vertical axis, the lower zone at an upper end thereof greater in cross-sectional area than the upper zone and at a lower end thereof less in cross-sectional area than the upper zone, the lower zone having an annular fluid inlet aperture at an outer extremity thereof at its upper end, and an exit aperture at its lower end, the exit aperture vertically aligned with a central axis of the upper zone, means for feeding fiber vertically downward through the passage, and means for feeding coating fluid into the passage through the inlet aperture to fill the lower zone and at least partially to fill the upper zone.
2. A fiber coating mechanism as claimed in claim 1 in which the passage is defined by a regulating valve and a cup, the upper zone defined by a bore through the valve, the lower zone defined by a lower part of the cup, and the annular aperture defined by an inner wall of the cup opposing an outer surface of the valve.
3. A fiber coating mechanism as claimed in claim 2 the cup having a nipple in a base thereof, the nipple having a tapered coating chamber therein.
4. A fiber coating mechanism as claimed in claim 2 in which the cup has a tapered fluid storage chamber above the annular aperture.
5. A fiber coating mechanism as claimed in claim 2, in which the valve is vertically reciprocal whereby the size of the annular aperture can be adjusted.
6. A fiber coating mechanism as claimed in claim 5 in which a stem of the valve screw engages a bore through a lid for the cup.
7. A fiber coating mechanism as claimed in claim 2 in which the cup has an inner wall which is steep at the top end thereof and becomes shallow towards the annular aperture.
8. A fiber coating mechanism as claimed in claim 3 in which the coating chamber is conical.
9. A fiber coating mechanism as claimed in claim 2 further comprising means for supplying coating fluid to the cup to a level whereby it is set a desired pressure head at the annular aperture.
10. A method of coating a fiber comprising feeding the fiber vertically downward through a passage filled with coating fluid, the passage having an upper zone within which air bubbles and turbulence are inevitably introduced into the fluid the upper zone being of sufficient length and cross-sectional area to permit the introduced bubbles to float upwardly therethrough, the passage further having a downwardly tapering lower zone, the method further comprising directing fluid uniformly radially inwardly and downwardly into the lower zone to suppress the introduced turbulence at an exit aperture at a lower end of the passage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000441786A CA1177614A (en) | 1983-11-23 | 1983-11-23 | Method and apparatus for use in coating an elongate filament |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000441786A CA1177614A (en) | 1983-11-23 | 1983-11-23 | Method and apparatus for use in coating an elongate filament |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1177614A true CA1177614A (en) | 1984-11-13 |
Family
ID=4126583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000441786A Expired CA1177614A (en) | 1983-11-23 | 1983-11-23 | Method and apparatus for use in coating an elongate filament |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1177614A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4823458A (en) * | 1983-12-21 | 1989-04-25 | Henkel Kommanditgesellschaft Auf Aktien | Foam bodied hair curler |
| US6431847B1 (en) * | 1999-04-06 | 2002-08-13 | Woodshed Technologies, Inc. | Apparatus for compounding resin and fiber |
| US6875385B2 (en) | 1999-04-06 | 2005-04-05 | Woodshed Technologies, Inc. | Method of compounding resin and fiber |
| US7169340B2 (en) | 1999-04-06 | 2007-01-30 | Hawley Ronald C | Resin and fiber compounding process for molding operations |
-
1983
- 1983-11-23 CA CA000441786A patent/CA1177614A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4823458A (en) * | 1983-12-21 | 1989-04-25 | Henkel Kommanditgesellschaft Auf Aktien | Foam bodied hair curler |
| US6431847B1 (en) * | 1999-04-06 | 2002-08-13 | Woodshed Technologies, Inc. | Apparatus for compounding resin and fiber |
| US6875385B2 (en) | 1999-04-06 | 2005-04-05 | Woodshed Technologies, Inc. | Method of compounding resin and fiber |
| US7169340B2 (en) | 1999-04-06 | 2007-01-30 | Hawley Ronald C | Resin and fiber compounding process for molding operations |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |