CA1076810A - Process for spinning glass fibers - Google Patents
Process for spinning glass fibersInfo
- Publication number
- CA1076810A CA1076810A CA245,386A CA245386A CA1076810A CA 1076810 A CA1076810 A CA 1076810A CA 245386 A CA245386 A CA 245386A CA 1076810 A CA1076810 A CA 1076810A
- Authority
- CA
- Canada
- Prior art keywords
- molten glass
- nozzle plate
- orifices
- orifice
- combined
- 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
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
- Y02P40/57—Improving the yield, e-g- reduction of reject rates
Landscapes
- Inorganic Fibers (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for spinning glass fibers by drawing individual filament from each orifice in a nozzle plate is improved by using a nozzle plate made of material having a contact angle of at least 60°
to molten glass and containing a large number of orifices, pitches between each orifice being less than 5 mm, and finding the end of individual filament by drawing gradually combined molten glass beads on the under surface of the nozzle plate so as to separate the molten glass into individual filament.
A process for spinning glass fibers by drawing individual filament from each orifice in a nozzle plate is improved by using a nozzle plate made of material having a contact angle of at least 60°
to molten glass and containing a large number of orifices, pitches between each orifice being less than 5 mm, and finding the end of individual filament by drawing gradually combined molten glass beads on the under surface of the nozzle plate so as to separate the molten glass into individual filament.
Description
1~768~
This invention relates to a process for spinning glass fibers. More particularly, this invention relates to an improved process for spinning glass fibers using a flat nozzle plate which is made of a material showing almost no wetting with molten glass and has a large number of orifices per unit area therein.
Heretofore various apparatuses for producing glass fibers have been proposed. A typical example of the apparatuses is a spinning furnace having a flat spinneret made of a platinum- :
rhodium alloy. Said spinneret is a flat plate made of a plati-num-rhodium alloy and has such a simple structure as having a few orifices with 1.5 - 3 mm in diameter therein. But the platinum-rhodium alloy has a defect in that a contact angle of it to molten glass is very small, i.e. wetting with molten glass ~ ;
is great. A spinneret made of a platinum-gold-rhodium alloy, ,~
which has been developed later, has a larger contact angle to molten glass than the platinum-rhodium alloy spinneret and thus wetting with molten glass is not so great. But it is inevitable in the case of using either the platinum-rhodium alloy or the platinum-gold-rhodium alloy that, if pitches between each orifice become narrower, once one of the filaments passing through an orifice is cut, molten glass bead would be formed on the exit hole of the orifice and spread over the surface of the orifice widely so as to cut other filaments passing through the adjacent orifices, and this phenomenon would proceed succes-sively until all the filaments are cut and the under surface of the spinneret would be covered with the molten glass delivered ;
from the orifices. Once such a phenomenon takes place, it is very difficult to separate into each filament, that is, to recover the state in which molten glass passing through one 30 orifice forms an independent stream of filament without being -combined with other molten glass passing through another :
10~68:5L0 orifice. Particularly if pitches between each orifice are less than 5 mm, it is completely impossible even for a skilled worker to separate into individual filaments so as to form each independent stream from each orifice according to the conven-tional process.
In order to improve such defects as mentioned above, a process for using tip nozzles has been developed. According to said process, since the area which can be wetted with molten glass from one nozzle is limited to the bottom of a tip, molten glass from one nozzle is enforced to form an independent stream without combined with molten glass from another nozzle.
Therefore separation of filaments can easily be carried out even if nozzles are placed closely. Thus it is possible to make more nozzles per unit area than thè flat spinnerets mentioned above and to increase the productivity remarkably. But the tip nozzle has, on the other hand, the following defects. The side wall of each tip nozzle needs some thickness and then there are concave parts among tips, and if one tip is placed very closely to another tip, molten glass would intrude into the concave .~ . . .
` 20 parts, which gives bad influence on the effect of the tip nozzle.
Further in order to increase the productivity, it is necessary to attach cooling apparatus to places between the two tips. By the reasons mentioned above, there is, as a matter of course, ,~ `
limitation to the number of nozzles per unit area. If too many ' tip nozzles are perforated in a nozzle plate, the shape of the nozzle plate should be enlarged and about 2000 holes seem to be the practical upper limit of the number of nozzles in the plate due to deformation of the plate. In addition, since the nozzle plate i5 made of an expensive platinum-rhodium or platinum-gold-rhodium alloy, the amount of used noble metals may increase with an increase of the number of nozzles, which results in an in- ;
crease in equipment investment and cost for the product.
This invention relates to a process for spinning glass fibers. More particularly, this invention relates to an improved process for spinning glass fibers using a flat nozzle plate which is made of a material showing almost no wetting with molten glass and has a large number of orifices per unit area therein.
Heretofore various apparatuses for producing glass fibers have been proposed. A typical example of the apparatuses is a spinning furnace having a flat spinneret made of a platinum- :
rhodium alloy. Said spinneret is a flat plate made of a plati-num-rhodium alloy and has such a simple structure as having a few orifices with 1.5 - 3 mm in diameter therein. But the platinum-rhodium alloy has a defect in that a contact angle of it to molten glass is very small, i.e. wetting with molten glass ~ ;
is great. A spinneret made of a platinum-gold-rhodium alloy, ,~
which has been developed later, has a larger contact angle to molten glass than the platinum-rhodium alloy spinneret and thus wetting with molten glass is not so great. But it is inevitable in the case of using either the platinum-rhodium alloy or the platinum-gold-rhodium alloy that, if pitches between each orifice become narrower, once one of the filaments passing through an orifice is cut, molten glass bead would be formed on the exit hole of the orifice and spread over the surface of the orifice widely so as to cut other filaments passing through the adjacent orifices, and this phenomenon would proceed succes-sively until all the filaments are cut and the under surface of the spinneret would be covered with the molten glass delivered ;
from the orifices. Once such a phenomenon takes place, it is very difficult to separate into each filament, that is, to recover the state in which molten glass passing through one 30 orifice forms an independent stream of filament without being -combined with other molten glass passing through another :
10~68:5L0 orifice. Particularly if pitches between each orifice are less than 5 mm, it is completely impossible even for a skilled worker to separate into individual filaments so as to form each independent stream from each orifice according to the conven-tional process.
In order to improve such defects as mentioned above, a process for using tip nozzles has been developed. According to said process, since the area which can be wetted with molten glass from one nozzle is limited to the bottom of a tip, molten glass from one nozzle is enforced to form an independent stream without combined with molten glass from another nozzle.
Therefore separation of filaments can easily be carried out even if nozzles are placed closely. Thus it is possible to make more nozzles per unit area than thè flat spinnerets mentioned above and to increase the productivity remarkably. But the tip nozzle has, on the other hand, the following defects. The side wall of each tip nozzle needs some thickness and then there are concave parts among tips, and if one tip is placed very closely to another tip, molten glass would intrude into the concave .~ . . .
` 20 parts, which gives bad influence on the effect of the tip nozzle.
Further in order to increase the productivity, it is necessary to attach cooling apparatus to places between the two tips. By the reasons mentioned above, there is, as a matter of course, ,~ `
limitation to the number of nozzles per unit area. If too many ' tip nozzles are perforated in a nozzle plate, the shape of the nozzle plate should be enlarged and about 2000 holes seem to be the practical upper limit of the number of nozzles in the plate due to deformation of the plate. In addition, since the nozzle plate i5 made of an expensive platinum-rhodium or platinum-gold-rhodium alloy, the amount of used noble metals may increase with an increase of the number of nozzles, which results in an in- ;
crease in equipment investment and cost for the product.
2 -... . . . . . . . ..
1~76~
Other processes are disclosed in, e.g. K.L. Leowenstein "The Manufactural Technology of Continuous Glass Fibers"
Elserier Scientific Publication Co., N.Y., 1973, but they are ;
insufficient in the above-mentioned points.
It is an object of the present invention to provide an improved process for spinning glass fibers stably with excellent productivity by using a special nozzle plate having a large number of orifices per unit area, easily finding the end of individual filament, and overcoming the defects of the known processes.
The present invention provides a process for spinning glass fibers by drawing individual filament from each orifice in a nozzle plate attached to a melting furnace, characterized by using a nozzle plate made of a material having a contact angle of 60 or more to molten glass and containing a large number of orifices per unit area so that molten glass effluent from the orifices may form combined beads, drawing gradually the combined molten glass beads on the under surface of the nozzle plate so as to separate the molten glass into individual filament from each orifice and finding the end of individual filament.
According to the process of the present invention, since the special nozzle plate having a large number of orifices per ;;
unit area ia used, the productivity of the nozzle plate per unit ;~
area is about 10 to 80 times as much as the conventional methods and glass fibers can be produced stably and continuously unlike the conventional methods. -In the present process, glass is melted down in a con-ventional melting furnace such as a bushing, a glass melting tank, or the like. At the bottom of the bushing, a special flat nozzle plate is attached. The nozzle plate must be made of a material having a contact angle of 60 or more to molten glass, preferably 90 or more.
1~76~
Other processes are disclosed in, e.g. K.L. Leowenstein "The Manufactural Technology of Continuous Glass Fibers"
Elserier Scientific Publication Co., N.Y., 1973, but they are ;
insufficient in the above-mentioned points.
It is an object of the present invention to provide an improved process for spinning glass fibers stably with excellent productivity by using a special nozzle plate having a large number of orifices per unit area, easily finding the end of individual filament, and overcoming the defects of the known processes.
The present invention provides a process for spinning glass fibers by drawing individual filament from each orifice in a nozzle plate attached to a melting furnace, characterized by using a nozzle plate made of a material having a contact angle of 60 or more to molten glass and containing a large number of orifices per unit area so that molten glass effluent from the orifices may form combined beads, drawing gradually the combined molten glass beads on the under surface of the nozzle plate so as to separate the molten glass into individual filament from each orifice and finding the end of individual filament.
According to the process of the present invention, since the special nozzle plate having a large number of orifices per ;;
unit area ia used, the productivity of the nozzle plate per unit ;~
area is about 10 to 80 times as much as the conventional methods and glass fibers can be produced stably and continuously unlike the conventional methods. -In the present process, glass is melted down in a con-ventional melting furnace such as a bushing, a glass melting tank, or the like. At the bottom of the bushing, a special flat nozzle plate is attached. The nozzle plate must be made of a material having a contact angle of 60 or more to molten glass, preferably 90 or more.
- 3 - ;
iL~7~8~L~
Contact angle of the material to molten glass is measured as follows. A little glass bead (0.1 to 0.2 g) is placed on a flat plate made of the material whose angle is to be measured, and the plate and the glass bead are put into a furnace in which the plate is placed horizontal, and kept for one hour at a constant temperature, e.g. 1100 to 1200C. Then they are taken out and quenched. Subsequently, they are photographed from the exactly lateral direction. Then the contact angle is measured using a conventional method. It is known that the `
contact angle measured by this quenching method is almost equal to the contact angle at high temperatures.
In the present invention, when a contact angle to molten glass is 90 or more, it is defined that the material has non-wetting property, and when a contact angle is 60 or more and less than 90, the material has little wetting property.
The materials having a contact angle of 90 or more to molten glass are particularly preferable to make a nozzle plate in the present invention. Examples of such materials are ~ `
graphite (150 measured at 1100C) or boron nitride (130 measured `
at 1100C). The materials having a contact angle of 60 or more and less than 90 to molten glass can be used for making a nozzle plate, if the spinning operation conditions, for instance speed, temperature, rate of molten glass delivery, viscosity, etc. are changed. Examples of such materials are a platinum-rhodium-gold alloy, a gold-palladium alloy, and the like.
The flat nozzle plate made of such materials as men- `
tioned above has a large number of orifices per unit area so that the molten glass effluent from the orifices may form combined molten glass beads. More concretely, pitches between each ori-fice are 5 mm or less, preferably from 0.5 to 2.5 mm. Since the diameter of an orifice is usually from 0.3 to 2.0 mm, the 1~76810 . .
number of orifices per unit area in the nozzle plate is prefer-ably 25 to 200 per square centimeter. Since the number of orifices per unit area in a conventional flat nozzle plate made of a platinum-rhodium alloy is about 2.4 per square centimeter, the value of 25 - 200 is 10 to 80 times as many as the conven-tional value. Thus the yield of glass fibers per unit area of the nozzle plate can increase up to 10 to 80 times as much as that which can be obtained in the conventional method.
The process of the present invention using such a special nozzle plate is explained in more detail below.
;; :
Combination of two or more streams of molten glass effluent from orifices in a nozzle plate is generally due to wetting property between the molten glass and the nozzle plate, that is, each stream of molten glass effluent from an orifice spreads outwards from the periphery of the orifice to combine with each other. Therefore, in order to prevent the combination of two or more streams of molten glass on the under surface of a nozzle plate, it is necessary to allow a considerable distance between two or more orifices so that each molten glass bead ;
formed from a stream of molten glass naturally effluent from an orifice should not be combined together. But even though the ~- conditions as mentioned above are satisfied, it has been impos-sible even for a skilled worker to separate the combined molten ' glass beads into each independent stream of filament from each orifice and to find the end of individual filament, so far as employing the conventional spinning process wherein each filament is drawn from each orifice.
On the contrary, according to the present process, the combined molten glass beads can easily be separated into indi-vidual filament and the end of individual filament can easily be found, since the nozzle plate is made of a material having non-.
613~
wetting or little wetting property, and the combined molten glass beads are drawn gradually from the under surface of the nozzle plate.
In the case of spinning glass fibers using a nozzle plate made of the material having a con-tact angle of 90 or more to molten glass, i.e. having non-wetting property, and pitches between each orifice being 5 mm or less, the following procedure can be employed. Since the n~ber of orifices per unit area is very large, and molten glass wets itself easily, each molten glass bead effluent from the orifices spreads on the under surface of the nozzle plate and eventually all beads combine with each other to cover the whole area of the surface. Since the nozzle plate has non-wetting property against molten glass, when the molten glass blanketing the under surface of the plate with increased viscosity is drawn downwards at a greater speed than the effluent speed of the molten glass from the melting furnace, the molten glass spreading over the whole surface of the nozzle plate is pulled back to each periphery of orifice and easily separated into individual filament. The greater the viscosity of molten ;
,.
glass blanketing the under surface of the nozzle plate becomes, the easier the separation into individual filament becomes due to an increase in amount of the molten glass drawn downwards and influence of the tensile force. Thus the end of individual filament can easily be found.
In the case of spinning glass fibers using a nozzle plate made of the material having a contact angle of 60 - 90 to molten glass, i.e. having little wetting property, and pitches between each orifice being 5 mm or less, the separation of the combined molten glass beads into individual filament can easily be attained in the same manner as mentioned above, i.e. drawing downwards gradually the molten glass effluent from the orifices .$
8~ .
and increasing the viscosity of the combined beads blanketing the under surface of the nozzle. If separation into individual filament is attained insufficièntly, an air stream is blown to the combined molten glass beads blanketing the under surface of the nozzle plate to cool and increase the viscosity of molten glass. Thus the end of individual filament can easily be found.
When the separation into individual filament is attained and stable windup of filaments begins~ air blowing is stopped. In-asmuch as tensile force applied to filaments has a sufficient influence on each periphery of meniscus formed under each orifice, the influence of surface tension to cut the filaments and to make glass beads decreases, and the stability of meniscus shaped under the orifices can be maintained.
A nozzle plate made of graphite or boron nitride is by far superior to conventional ones in wetting and can be used for spinning glass fibers easily to obtain excellent products. A
nozzle plate made of a platinum-rhodium-gold alloy having a con-tact angle of 60 or more to molten glass is very excellent in strength, durability, oxidation resistance, and the like and 20 can be used for stable spinning of glass fibers for a long i period. On the other hand, the nozzle plate made of graphite or boron nitride is slightly inferior to that made of the above mentioned alloy in durability, but since the former has non-wetting property, it has many advantages, particularly an easy `-operation and low cost.
The following examples will serve further to illustrate the present invention.
Example 1 A nozzle plate made of graphite and having 87 orifices of 1.0 mm in diameter, the number of orifices per square centi-meter being 29, was attached to the bottom of a conventional 683L~
bushing. As glass, E-glass was used for spinning. From each orifice, molten glass was delivered at the rate of 0.3 g/min.
Each molten glass bead naturally effluent from each orifice was combined together and blanketed the under surface of the nozzle plate while increasing the viscosity of the molten glass. Then the molten glass blanketing the surface was drawn downwards at a greater speed than the effluent speed of the molten glass from the bushing. The combined molten glass beads were separated into -` individual rilaments, and the ends of individual filaments could easily be found. The filaments were wound up at a speed of ; 1000 m/min. Glass filament with a diameter of 13 microns was -~
obtained. Spinning temperature was 1120C. The contact angle ; between the molten glass and the graphite was 150 at 1100C.
Using a nozzle plate made of graphite and having 400 orifices of 1.0 mm in diameter, the number of orifices per square centimeter being 36, and using the same manner as mentioned above, glass filaments having the same fineness were obtained at a windup speed of 500 m/min.
Example 2 ;
Using a nozzle plate made of boron nitride instead of graphite, the procedure of Example 1 was repeated to obtain the same results as Example 1. The contact angle between the molten glass and the boron nitride was 130 at 1100C. ;
Example 3 Nozzle plates made of the platinum-rhodium-gold alloy (composition: Pt 85.5% by weight, Rh 9.5% by weight and Au 5%
by weight) and having o~ifices of 1.3 mm in diameter, the numbers of orifices being as shown in Table 1 ware used. Each nozzle plate was attached to the bottom of a conventional bushing and spinning of glass fibers was carried out using E-glass as used in Example 1. From each orifice, molten glass was delivered , ~
~07 ~8~ [) !
e.g. at the rate of about 0.6 y/min. Each molten glass bead naturally effluent from each orifice was combined together and blanketed the under surface of the nozzle plate. Then the molten glass blanketing the surface was drawn downwards at a greater speed than the effluent speed of the molten glass from the orifices. The combined molten glass beads were separated into individual filaments and the ends of individual filaments could easily be found. The filaments were wound up at speeds of - 1000 - 3000 m/min as shown in Table 1. Thus glass filaments with diameiers of 6 - 10 microns were obtained as shown in ~ Table 1.
- Table 1 Run No. of No. of Windup Spinning Fineness No. orifices orific2es speed temp. (microns) per cm (m/min) (C)
iL~7~8~L~
Contact angle of the material to molten glass is measured as follows. A little glass bead (0.1 to 0.2 g) is placed on a flat plate made of the material whose angle is to be measured, and the plate and the glass bead are put into a furnace in which the plate is placed horizontal, and kept for one hour at a constant temperature, e.g. 1100 to 1200C. Then they are taken out and quenched. Subsequently, they are photographed from the exactly lateral direction. Then the contact angle is measured using a conventional method. It is known that the `
contact angle measured by this quenching method is almost equal to the contact angle at high temperatures.
In the present invention, when a contact angle to molten glass is 90 or more, it is defined that the material has non-wetting property, and when a contact angle is 60 or more and less than 90, the material has little wetting property.
The materials having a contact angle of 90 or more to molten glass are particularly preferable to make a nozzle plate in the present invention. Examples of such materials are ~ `
graphite (150 measured at 1100C) or boron nitride (130 measured `
at 1100C). The materials having a contact angle of 60 or more and less than 90 to molten glass can be used for making a nozzle plate, if the spinning operation conditions, for instance speed, temperature, rate of molten glass delivery, viscosity, etc. are changed. Examples of such materials are a platinum-rhodium-gold alloy, a gold-palladium alloy, and the like.
The flat nozzle plate made of such materials as men- `
tioned above has a large number of orifices per unit area so that the molten glass effluent from the orifices may form combined molten glass beads. More concretely, pitches between each ori-fice are 5 mm or less, preferably from 0.5 to 2.5 mm. Since the diameter of an orifice is usually from 0.3 to 2.0 mm, the 1~76810 . .
number of orifices per unit area in the nozzle plate is prefer-ably 25 to 200 per square centimeter. Since the number of orifices per unit area in a conventional flat nozzle plate made of a platinum-rhodium alloy is about 2.4 per square centimeter, the value of 25 - 200 is 10 to 80 times as many as the conven-tional value. Thus the yield of glass fibers per unit area of the nozzle plate can increase up to 10 to 80 times as much as that which can be obtained in the conventional method.
The process of the present invention using such a special nozzle plate is explained in more detail below.
;; :
Combination of two or more streams of molten glass effluent from orifices in a nozzle plate is generally due to wetting property between the molten glass and the nozzle plate, that is, each stream of molten glass effluent from an orifice spreads outwards from the periphery of the orifice to combine with each other. Therefore, in order to prevent the combination of two or more streams of molten glass on the under surface of a nozzle plate, it is necessary to allow a considerable distance between two or more orifices so that each molten glass bead ;
formed from a stream of molten glass naturally effluent from an orifice should not be combined together. But even though the ~- conditions as mentioned above are satisfied, it has been impos-sible even for a skilled worker to separate the combined molten ' glass beads into each independent stream of filament from each orifice and to find the end of individual filament, so far as employing the conventional spinning process wherein each filament is drawn from each orifice.
On the contrary, according to the present process, the combined molten glass beads can easily be separated into indi-vidual filament and the end of individual filament can easily be found, since the nozzle plate is made of a material having non-.
613~
wetting or little wetting property, and the combined molten glass beads are drawn gradually from the under surface of the nozzle plate.
In the case of spinning glass fibers using a nozzle plate made of the material having a con-tact angle of 90 or more to molten glass, i.e. having non-wetting property, and pitches between each orifice being 5 mm or less, the following procedure can be employed. Since the n~ber of orifices per unit area is very large, and molten glass wets itself easily, each molten glass bead effluent from the orifices spreads on the under surface of the nozzle plate and eventually all beads combine with each other to cover the whole area of the surface. Since the nozzle plate has non-wetting property against molten glass, when the molten glass blanketing the under surface of the plate with increased viscosity is drawn downwards at a greater speed than the effluent speed of the molten glass from the melting furnace, the molten glass spreading over the whole surface of the nozzle plate is pulled back to each periphery of orifice and easily separated into individual filament. The greater the viscosity of molten ;
,.
glass blanketing the under surface of the nozzle plate becomes, the easier the separation into individual filament becomes due to an increase in amount of the molten glass drawn downwards and influence of the tensile force. Thus the end of individual filament can easily be found.
In the case of spinning glass fibers using a nozzle plate made of the material having a contact angle of 60 - 90 to molten glass, i.e. having little wetting property, and pitches between each orifice being 5 mm or less, the separation of the combined molten glass beads into individual filament can easily be attained in the same manner as mentioned above, i.e. drawing downwards gradually the molten glass effluent from the orifices .$
8~ .
and increasing the viscosity of the combined beads blanketing the under surface of the nozzle. If separation into individual filament is attained insufficièntly, an air stream is blown to the combined molten glass beads blanketing the under surface of the nozzle plate to cool and increase the viscosity of molten glass. Thus the end of individual filament can easily be found.
When the separation into individual filament is attained and stable windup of filaments begins~ air blowing is stopped. In-asmuch as tensile force applied to filaments has a sufficient influence on each periphery of meniscus formed under each orifice, the influence of surface tension to cut the filaments and to make glass beads decreases, and the stability of meniscus shaped under the orifices can be maintained.
A nozzle plate made of graphite or boron nitride is by far superior to conventional ones in wetting and can be used for spinning glass fibers easily to obtain excellent products. A
nozzle plate made of a platinum-rhodium-gold alloy having a con-tact angle of 60 or more to molten glass is very excellent in strength, durability, oxidation resistance, and the like and 20 can be used for stable spinning of glass fibers for a long i period. On the other hand, the nozzle plate made of graphite or boron nitride is slightly inferior to that made of the above mentioned alloy in durability, but since the former has non-wetting property, it has many advantages, particularly an easy `-operation and low cost.
The following examples will serve further to illustrate the present invention.
Example 1 A nozzle plate made of graphite and having 87 orifices of 1.0 mm in diameter, the number of orifices per square centi-meter being 29, was attached to the bottom of a conventional 683L~
bushing. As glass, E-glass was used for spinning. From each orifice, molten glass was delivered at the rate of 0.3 g/min.
Each molten glass bead naturally effluent from each orifice was combined together and blanketed the under surface of the nozzle plate while increasing the viscosity of the molten glass. Then the molten glass blanketing the surface was drawn downwards at a greater speed than the effluent speed of the molten glass from the bushing. The combined molten glass beads were separated into -` individual rilaments, and the ends of individual filaments could easily be found. The filaments were wound up at a speed of ; 1000 m/min. Glass filament with a diameter of 13 microns was -~
obtained. Spinning temperature was 1120C. The contact angle ; between the molten glass and the graphite was 150 at 1100C.
Using a nozzle plate made of graphite and having 400 orifices of 1.0 mm in diameter, the number of orifices per square centimeter being 36, and using the same manner as mentioned above, glass filaments having the same fineness were obtained at a windup speed of 500 m/min.
Example 2 ;
Using a nozzle plate made of boron nitride instead of graphite, the procedure of Example 1 was repeated to obtain the same results as Example 1. The contact angle between the molten glass and the boron nitride was 130 at 1100C. ;
Example 3 Nozzle plates made of the platinum-rhodium-gold alloy (composition: Pt 85.5% by weight, Rh 9.5% by weight and Au 5%
by weight) and having o~ifices of 1.3 mm in diameter, the numbers of orifices being as shown in Table 1 ware used. Each nozzle plate was attached to the bottom of a conventional bushing and spinning of glass fibers was carried out using E-glass as used in Example 1. From each orifice, molten glass was delivered , ~
~07 ~8~ [) !
e.g. at the rate of about 0.6 y/min. Each molten glass bead naturally effluent from each orifice was combined together and blanketed the under surface of the nozzle plate. Then the molten glass blanketing the surface was drawn downwards at a greater speed than the effluent speed of the molten glass from the orifices. The combined molten glass beads were separated into individual filaments and the ends of individual filaments could easily be found. The filaments were wound up at speeds of - 1000 - 3000 m/min as shown in Table 1. Thus glass filaments with diameiers of 6 - 10 microns were obtained as shown in ~ Table 1.
- Table 1 Run No. of No. of Windup Spinning Fineness No. orifices orific2es speed temp. (microns) per cm (m/min) (C)
4 2000 45 1000 1140 6 The contact angle between the molten glass and the platinum-rhodium-gold alloy was 76 at 1200C. When an air stream of 10 - 50 l./min was blown to the combined molten glass beads blanketing the surface of the nozzle plate for cooling during the end of individual filament being found, the separa-tion of the molten glass into individual filaments emerging from each orifice could be attained more easily comparing with the case of blowing no air. The air stream was blown in the direc-tion of the orifices suitable for cooling meniscuses of the molten glass emerging from the orifices. The air blowing was stopped after stable windup of the filaments began.
,: ', 68~1~
Example 4 Using a nozzle plate made of the gold-palladium alloy (composition: Au 80% by weight and Pd 20% by weight), glass fibers were spun in the same manner as Example 3 Run Nos. 1, 2 and 3. Almost the same results as in Example 3 Run Nos. 1, 2 and 3 were obtained. Since heat resistance of the gold-palladium alloy is inferior to that of the platinum-rhodium-gold alloy ` used in Example 3, the former has a disadvantage in useful life.
The contact angle between the molten glass and the gold-palladium 10 alloy was 82 at 1200C.
Referential Example A platinum-rhodium alloy which has widely been used for making a nozzle plate has a contact angle of 32 at 1200C to molten glass. Using a nozzle plate made of the platinum-rhodium alloy, spinning of glass fibers was tried in the same manner as Example 3 Run No. 2. Since the platinum-rhodium alloy has wetting property to molten glass, separation of the filaments was very difficult and stable spinning of glass fibers could not be attained.
As is clear from the above examples, it is not only pos-sible to spin glass fibers stably but also easy to produce very fine glass fibers since the finding of the end of individual filament is very easy according to the present process. It is also possible to increase production of glass fibers up to 10 to 80 times as much as the conventional process if a nozzle plate of the same area as used in the conventional process is used.
Further it is possible to produce directly the strands composed of remarkably increased number of the filaments without employing : conventional processes of warp beaming, doubling and the like.
According to the present process, glass fibers can be produced ;; in large scale and economically.
1` :
: ~ I
.~ :
,: ', 68~1~
Example 4 Using a nozzle plate made of the gold-palladium alloy (composition: Au 80% by weight and Pd 20% by weight), glass fibers were spun in the same manner as Example 3 Run Nos. 1, 2 and 3. Almost the same results as in Example 3 Run Nos. 1, 2 and 3 were obtained. Since heat resistance of the gold-palladium alloy is inferior to that of the platinum-rhodium-gold alloy ` used in Example 3, the former has a disadvantage in useful life.
The contact angle between the molten glass and the gold-palladium 10 alloy was 82 at 1200C.
Referential Example A platinum-rhodium alloy which has widely been used for making a nozzle plate has a contact angle of 32 at 1200C to molten glass. Using a nozzle plate made of the platinum-rhodium alloy, spinning of glass fibers was tried in the same manner as Example 3 Run No. 2. Since the platinum-rhodium alloy has wetting property to molten glass, separation of the filaments was very difficult and stable spinning of glass fibers could not be attained.
As is clear from the above examples, it is not only pos-sible to spin glass fibers stably but also easy to produce very fine glass fibers since the finding of the end of individual filament is very easy according to the present process. It is also possible to increase production of glass fibers up to 10 to 80 times as much as the conventional process if a nozzle plate of the same area as used in the conventional process is used.
Further it is possible to produce directly the strands composed of remarkably increased number of the filaments without employing : conventional processes of warp beaming, doubling and the like.
According to the present process, glass fibers can be produced ;; in large scale and economically.
1` :
: ~ I
.~ :
Claims (4)
1. In a process for starting up a method for the continuous spinning of glass fibers downwardly from a nozzle plate having a plurality of orifices by drawing an individual filament from each orifice, said plurality of orifices being in a horizontal flat nozzle plate attached to a lower surface of a melting furnace, the improvement which consists essentially of the steps of using a nozzle plate made of a material having a con-tact angle of 60° or more to molten glass and containing 25 -200 orifices per cm2 so that molten glass effluent from the orifices may form combined beads, forming combined molten glass beads spread over the under surface of the nozzle plate, drawing the combined molten glass beads spread over the under surface of the nozzle plate at a greater speed than the effluent speed of the molten glass from each orifice so as to separate the molten glass into an individual filament from each orifice, while maintaining a normal spinning tempera-ture, and finding the ends of the individual filaments.
2. A process according to Claim 1, wherein the nozzle plate made of a material having a contact angle of 90°
or more to molten glass is used.
or more to molten glass is used.
3, A process according to claim 2 wherein the nozzle plate made of graphite or boron nitride is used.
4. A process according to claim 1, wherein the nozzle plate is made of a material having a contact angle of 60° - 90° to molten glass and an air stream is blown to the combined molten glass beads on the under surface of the nozzle plate until the combined molten glass beads separate into individual filaments and stable drawing of individual filaments is attained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA245,386A CA1076810A (en) | 1976-02-10 | 1976-02-10 | Process for spinning glass fibers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA245,386A CA1076810A (en) | 1976-02-10 | 1976-02-10 | Process for spinning glass fibers |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1076810A true CA1076810A (en) | 1980-05-06 |
Family
ID=4105199
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA245,386A Expired CA1076810A (en) | 1976-02-10 | 1976-02-10 | Process for spinning glass fibers |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1076810A (en) |
-
1976
- 1976-02-10 CA CA245,386A patent/CA1076810A/en not_active Expired
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