CA1074118A - Method and apparatus for eliminating external hot gas attenuation with rotary fiberization of glass - Google Patents
Method and apparatus for eliminating external hot gas attenuation with rotary fiberization of glassInfo
- Publication number
- CA1074118A CA1074118A CA224,807A CA224807A CA1074118A CA 1074118 A CA1074118 A CA 1074118A CA 224807 A CA224807 A CA 224807A CA 1074118 A CA1074118 A CA 1074118A
- Authority
- CA
- Canada
- Prior art keywords
- rotor
- diameter
- orifices
- glass
- peripheral wall
- 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
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/04—Manufacture of glass fibres or filaments by using centrifugal force, e.g. spinning through radial orifices; Construction of the spinner cups therefor
- C03B37/045—Construction of the spinner cups
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Inorganic Fibers (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
Abstract
METHOD AND APPARATUS FOR ELIMINATING EXTERNAL HOT GAS
ATTENUATION IN THE ROTARY FIBERIZATION OF GLASS
Abstract of The Disclosure By controlling the design and operational parameters in accordance with particular relationships continuous or long fibers having an average diameter of 7 microns or less can be formed by passing molten material through orifices in a peripheral wall of a rotor without using conventional hot gas blast attenuation externally of the rotor. The fibers are collected in the form of a strand or rope. The rotors utilized in the preferred embodiment of the present invention have a peripheral wall with at least 40,000 orifices having diameters of about 18 mils or less. As one of the design parameters, orifice diameter, changes during the life of the rotor, operational parameters are adjusted to maintain the desired relationships between the various design and operational parameters.
ATTENUATION IN THE ROTARY FIBERIZATION OF GLASS
Abstract of The Disclosure By controlling the design and operational parameters in accordance with particular relationships continuous or long fibers having an average diameter of 7 microns or less can be formed by passing molten material through orifices in a peripheral wall of a rotor without using conventional hot gas blast attenuation externally of the rotor. The fibers are collected in the form of a strand or rope. The rotors utilized in the preferred embodiment of the present invention have a peripheral wall with at least 40,000 orifices having diameters of about 18 mils or less. As one of the design parameters, orifice diameter, changes during the life of the rotor, operational parameters are adjusted to maintain the desired relationships between the various design and operational parameters.
Description
This invention relates to a method and apparatus for forming fibers from molten mineral material such as glass and, in particular, to a rotary fiberizing apparatus and method for producing a strand or rope comprising contin-uous or very long fibers of 7 microns diameter or less without using the conventional external hot gas attenuating technique.
The fiberization of molten mineral material such as glass can be accomplished by several known methods. One conventional method is rotary fiberi~ation. At least as early as 1933 it was known to produce glass fibers by centri-fugally forcing molten glass through perforations in the `
periphery of a rapidly rotating spinner or rotor followed by ripping the fibers apart by an annular air current traveling transverse to the emerging fibers, as evidenced by German Patent l~o. 571,807. It has also been known, at least since 19~0t to make glass fibers purely by the action o~ a rotary spinner, as shown by U.S. Patent No. ~,192,944. After leaving the perforations in the periphery of the rotor, the fibers were attenuated somewhat due to their engagement with the relatively quiescent air surrounding the rotor, but, as repor-ted in U.S. Patent No. 2,431,205, the degree of ~ttenuation caused by this effect is very limited. To increase the degree of attenuation and thus reduce the fiber diameter, this latter patent proposed to anchor the streams or fibers at a point removed fro~ the rotor. In U.S. Patent No.
The fiberization of molten mineral material such as glass can be accomplished by several known methods. One conventional method is rotary fiberi~ation. At least as early as 1933 it was known to produce glass fibers by centri-fugally forcing molten glass through perforations in the `
periphery of a rapidly rotating spinner or rotor followed by ripping the fibers apart by an annular air current traveling transverse to the emerging fibers, as evidenced by German Patent l~o. 571,807. It has also been known, at least since 19~0t to make glass fibers purely by the action o~ a rotary spinner, as shown by U.S. Patent No. ~,192,944. After leaving the perforations in the periphery of the rotor, the fibers were attenuated somewhat due to their engagement with the relatively quiescent air surrounding the rotor, but, as repor-ted in U.S. Patent No. 2,431,205, the degree of ~ttenuation caused by this effect is very limited. To increase the degree of attenuation and thus reduce the fiber diameter, this latter patent proposed to anchor the streams or fibers at a point removed fro~ the rotor. In U.S. Patent No.
2,497,369 it wais proposed to heat certrifugally formed primary ~ -fibers externally of the rotor to further attenuate the fibers.
None of the above mentioned references revealed the diameter of the glass fibers produced by the disclosed processes, but later reEerences evidenced tllat the ~iber diameter was at least 5 microns greater than was possible rw/
~0'7~
using the more costly flame attenuation fiberizing technique, e.g., see U.S. Patent Nos. 2,609,566 and Re 24,708. The former patent proposed to correct ~his defi-ciency by subjecting the centriugally drawn out primary fibers to further attenuation by the action of a transverse blast of hot gas. This gas had to have a temperature and a velocity sufficient to soften and attenuate the primary fibers. The gas blast was provided by the combustion of substantial quantities of fuel to produce a gaseous stream having a velocity of at least 1,200 feet per second and a temperature of at least 3,000F.
As disclosed in U.S. Patent Nos. 3,040,377 and
None of the above mentioned references revealed the diameter of the glass fibers produced by the disclosed processes, but later reEerences evidenced tllat the ~iber diameter was at least 5 microns greater than was possible rw/
~0'7~
using the more costly flame attenuation fiberizing technique, e.g., see U.S. Patent Nos. 2,609,566 and Re 24,708. The former patent proposed to correct ~his defi-ciency by subjecting the centriugally drawn out primary fibers to further attenuation by the action of a transverse blast of hot gas. This gas had to have a temperature and a velocity sufficient to soften and attenuate the primary fibers. The gas blast was provided by the combustion of substantial quantities of fuel to produce a gaseous stream having a velocity of at least 1,200 feet per second and a temperature of at least 3,000F.
As disclosed in U.S. Patent Nos. 3,040,377 and
3,0~0,736, it is also known to make continuous glass fibers by rotary fiberization, but these processes also included hot gas attenuation externally of the rotor.
From the issuance of Patent No. 2,609,566 in ; 1952 and until the present time a large number of advance-ments ha~e been made in the rotary fiberization field, but none have accomplished the manufacture of glass fibers hav-ing an average diameter below 7 microns, and particularly below 5 microns, without the necessity of also using a ~ -relatively high temperature gaseous blas~ to attenuate the primary fibers. It would be highly desirable to eliminate the hot gas blast or equivalent high energy usage attenuation step without sacrificing the desirably small fiber diameter it produces, particularly in view of the energy crisis and the resultant rapid increase in the prices of all fuels.
For example, in a typical rotary fiberization process as much as about 7,000 to 8,000 cubic feet of natural gas, or an equivalent amount of other fuel, is required for external jet blast attenuation for every ton of glass fiber produced. ~- ;
- 2 - ;
rw/
7~ ~L8 In a typical rotary fiberization process making 4-7 micron fibers by forcing the glass through 24 mil ori~ices in the rotor and attenuating the primary fibers with such a hot gaseous blast, the fiber diameter jumps to 10 to 15 microns when the burners providing the heat for the -hot gaseous blast are turned off.
It has also been suggestea in U.S. Patent No.
3,511,306 to make the orifices in the rotor as small as 10 mils to make staple fiber having a diameter of 4 to 1~ 10 microns, but it was not recognized that, by carefully controlling the relationship between the process vari-ables, the hot blast attenuation could be eliminated.
This reference, typical of the prior art, included hot gas blast attenuation as one of the process steps.
While some of the above prior art processes pro-duce fibers ha~ing diameters of 7 microns or less, these processes present several problems. The larye volume of fuel such as natural gas utilized by such processes is not always readily available and acute shortages are fore-cast. ConsequPntly, production can be interrupted or slowed by the unavailability of sufficient natural gas ~or the process and other gaseous fuels such as propane or -~
butane increase the operating costs substantially.
It is desirable to eliminate the additional expense of providing the blast of hot gases for attenu-ation plus the maintenance and related problems associated with the burners used in the attenuating apparatus. Also, every fuel burning step produces pollutants that must be dealt with causing an additional operating expense.
Finally, the additional heat added by the attenuating burners must be absorbed in the collection chamber prior to winding the strand or rope into a packaye.
~ 3 rw/
According to the present invention, there is provided a method of producing continuous or long fibers having an average diameter of less than about 7 microns from molten glass material, the method including the steps of introducing the molten material at a rate of hundreds of pounds per hour into a rotating rotor internal of a peripheral wall of the rotor, the peripheral wall containing orifices having a diameter no greater than about 18 mils. The molten material is passed through the orifices, and the relationship of design and operational parameters, consisting essentially of density, viscosity and rate of flow through the rotor of the molten material, peripheral wall thickness, interior diameter, rotational speed of the rotor, number and diameter of orifices in the ; rotor, head of molten material on the in-terior surface of the peripheral wall of the rotor are so controlled as to form the fibers having an average diameter of no more than about 7 microns without using additional attenuating means externally of the rotor.
It is an object of the invention to produce continuous fibers having diameters of 7 microns or less ; solely by passing molten material through orifices of a rotor into a relatively cool environment, thus eliminating the hot gas blast used in the prior art and the fuel usage associated therewith.
Applicants have discovered that it is possible to make continuous glass fibers having an average diameter of 7 microns or less, preferably 5 microns or less, and most preferably 4 microns or less by passing molten mineral material such as glass through orifices in a peripheral wall of a rotor and into a relatively cool environment.
Rotors having a large number of orifices, each having an _ sb/)i) .: . .. . . .. ... . . . . .
~L~7~
initial diameter of less than about 18 mils, are able to form primary fibers having diameters of less than 7 microns, e.g., 3 to 5 microns, if the relationship between the process variables are controlled in accordance with particular B 4a -sb/ ' ;~
~.~7~
1 relationships. It is even possible to produce sub-micron fibers using rotors whose orifice diameters are 2 mils or less.
With this arrangement, primary continuous fibers issue from the orifices, are twisted into a rope or strand by the spinning action of the rotor, and the rope or strand is pulled downward and wound into a package or further processed. Because of the relatively low temperature of the ambient air sur-rounding the rotor, at least the surfaces of the glass fibers are quickly cooled below the softening point of the glass. The continuous fibers are quickly cooled by the relatively cool environment surrounding the rotor. Unlike the prior art processes, the con-tinuous fibers are not heated, or their rate of cooling reduced, externally of the rotor to cause attenuation - in the present process.
The continuous fibers formed by the process and apparatus of the present invention have a narrower diameter distribution than the fibers produced by the prior art processes using hot gas blast attenuation~
For the purpose of this application, the term "average diameter" when referring to the fiber diameter is used in the sense of the conventional arithmetic or mean diameter obtained by averaging results of a microscopic determination.
Detc~iled Description of The Invention The drawing illustrates the preferred apparatus of the present invention. The apparatus is supported on conventional framework, but to better illustrate the apparatus the supporting framework has been omitted rom the drawing.
~' ~ - ,:
' ., ~ . ~. . . .
The apparatus comprises a drive shaft 32 which carries a spinner or rotor 34. The drive shaft is supported by, and rotatably mounted within, a tubular housing 36 by means of a pair of conventional bearing assemblies that are mounted in the tubular housing 36 in a conventional manner. The upper portion of the drive shaft 32 is provided with a sheave 40. The sheave is connected to a variable speed motor 42 or other con-ventional drive means by belt drive 44. Thus the rotation of the spinner 34 is affected by the motor 42 ich drives the drive shaft 32.
- The rotor 34 comprises a bottom wall 46, a peripheral wall ~7 containing orifices 48, and a re-inforcing upper wall ring 50 extending inwardly from the upper edge of the peripheral wall 47. The rotor is typically 12, 15, 18, 24 or more inches in interior diameter and has a centrally located aperture through which a threaded portion of the drive shaft 32 passes.
Smaller diameter rotors are operable, but are not de~irable because the output per unLt of height of the peripheral wall is undesirably low. A nut 52 on the threaded portion of the drive shaft plants the bottom wall of the rotor between itself and a shoulder on the drive shaft in a conventional manner. The bottom wall 46 forms the floor of the rotor. The lower edge portion of the peripheral wall 47 can be welded or otherwise affixed to the periphery of the bottom wall 46 and the upper edge portion of the peripheral wall 47 can be welded or otherwise secured to the upper reinforcing wall 50 which lends needed strength to the rotor when it is rotating at high speed at temperatures which tend -to ~, ' .
rw/ _ 6 _ -. . . . . . . . . .
~L~7~ ,y weaken the metal of the peripheral wall. The rotors ean be a one piece casting made by known casting techniques, such as investment casting, and this is preferred.
The peripheral wall 4~ of the rotor.is pro- -vided with a plurality of orifices 48 with the longitu-dinal axis of the orifices extending radially through the peripheral wall 47. In order to form continuous fibers having an average diameter of 3 to 5 microns by passing glass through the orifices at a rate of at least 600 lbs. per hr. and into a relatively cool environment, it is preferred to have at least 40,000 to 100,000 orifices in the peripheral wall with each orifice having an initial diameter ranging up to about 18 mils, preferably 12 mils, and most preferably up to about 10 mils or less. The spacing between orifices is typically about 36 mils, plus or minus about 10 mils.
Hot gasses from the burners 28, usually three such burners are sufficient, are directed onto the interior of the peripheral wall 47 of the rotor to maintain the peripheral wall at temperatures sufficient to maintain the glass at the proper viscosity to produce the desired fiber diameter in accordance with the present invention. For typical glass compositions presently being used, the interior peripharal wall is usually maintained at a temperature in the range of about 1700F. to 2100F~ ;
A combustible mixture is supplied to the burners 28 by conventional means.
The molten glass feed 26 flows rom a suitable source (not shown~ such as a forehearth, or oth~r con-rw/
- .
. ~
~7~
ventional glass melting and/or refining means, e.g. an electric furnace. The molten glass feed 26 enters the rotor at a point offset from its center. Due to the centrifugal forces generated by the rotation of the rotor, the molten glass flows toward the peripheral wall of the rotor and up the interior surface of the peripheral wall. When a sufficient head "h" has been built up on the interior wall of the rotor, and when the other operational and design parameters are properly controlled, the molten glass is forced through the orifices by the centrifugal force of the rotor to form contin-uous fibers having an average diameter of 7 microns or less.
The magnitude "h" can be controlled by controlling the rate of molten glass feed 26, the interior temperature of the rotor, and the rotational speed of the rotor.
A guard ring 54 surrounds the rotor for safety purposes and also to eliminate any disturbances in the fiber flow that might be caused by air currents in the plant.
The temperature of the environment within the guard member 54 is not critical so long as the temperature is below that that would be required to soften and thus attenuate the primary fibers. Normally some plant air is inherently drawn into the opening between guard 54 and the peripheral wall of the rotor 47 by the downward movement of the fibers.
Any heat c-ontained in the environment within ring 54 because of the continuous flow of hot fibers therethrough, is purely coincidental because the advantage of the present invention is thal: it is not necessary to heat this~environ-ment to a temperature sufficient to jrr:~
.
.
:' '. ~ : .
1 promote and permit attenuation of the fibers. Its sole function is to cool the continuous or long fibers.
In operation, the burners 28 heat both the bottom wall 46 and the interior of the peripheral wall
From the issuance of Patent No. 2,609,566 in ; 1952 and until the present time a large number of advance-ments ha~e been made in the rotary fiberization field, but none have accomplished the manufacture of glass fibers hav-ing an average diameter below 7 microns, and particularly below 5 microns, without the necessity of also using a ~ -relatively high temperature gaseous blas~ to attenuate the primary fibers. It would be highly desirable to eliminate the hot gas blast or equivalent high energy usage attenuation step without sacrificing the desirably small fiber diameter it produces, particularly in view of the energy crisis and the resultant rapid increase in the prices of all fuels.
For example, in a typical rotary fiberization process as much as about 7,000 to 8,000 cubic feet of natural gas, or an equivalent amount of other fuel, is required for external jet blast attenuation for every ton of glass fiber produced. ~- ;
- 2 - ;
rw/
7~ ~L8 In a typical rotary fiberization process making 4-7 micron fibers by forcing the glass through 24 mil ori~ices in the rotor and attenuating the primary fibers with such a hot gaseous blast, the fiber diameter jumps to 10 to 15 microns when the burners providing the heat for the -hot gaseous blast are turned off.
It has also been suggestea in U.S. Patent No.
3,511,306 to make the orifices in the rotor as small as 10 mils to make staple fiber having a diameter of 4 to 1~ 10 microns, but it was not recognized that, by carefully controlling the relationship between the process vari-ables, the hot blast attenuation could be eliminated.
This reference, typical of the prior art, included hot gas blast attenuation as one of the process steps.
While some of the above prior art processes pro-duce fibers ha~ing diameters of 7 microns or less, these processes present several problems. The larye volume of fuel such as natural gas utilized by such processes is not always readily available and acute shortages are fore-cast. ConsequPntly, production can be interrupted or slowed by the unavailability of sufficient natural gas ~or the process and other gaseous fuels such as propane or -~
butane increase the operating costs substantially.
It is desirable to eliminate the additional expense of providing the blast of hot gases for attenu-ation plus the maintenance and related problems associated with the burners used in the attenuating apparatus. Also, every fuel burning step produces pollutants that must be dealt with causing an additional operating expense.
Finally, the additional heat added by the attenuating burners must be absorbed in the collection chamber prior to winding the strand or rope into a packaye.
~ 3 rw/
According to the present invention, there is provided a method of producing continuous or long fibers having an average diameter of less than about 7 microns from molten glass material, the method including the steps of introducing the molten material at a rate of hundreds of pounds per hour into a rotating rotor internal of a peripheral wall of the rotor, the peripheral wall containing orifices having a diameter no greater than about 18 mils. The molten material is passed through the orifices, and the relationship of design and operational parameters, consisting essentially of density, viscosity and rate of flow through the rotor of the molten material, peripheral wall thickness, interior diameter, rotational speed of the rotor, number and diameter of orifices in the ; rotor, head of molten material on the in-terior surface of the peripheral wall of the rotor are so controlled as to form the fibers having an average diameter of no more than about 7 microns without using additional attenuating means externally of the rotor.
It is an object of the invention to produce continuous fibers having diameters of 7 microns or less ; solely by passing molten material through orifices of a rotor into a relatively cool environment, thus eliminating the hot gas blast used in the prior art and the fuel usage associated therewith.
Applicants have discovered that it is possible to make continuous glass fibers having an average diameter of 7 microns or less, preferably 5 microns or less, and most preferably 4 microns or less by passing molten mineral material such as glass through orifices in a peripheral wall of a rotor and into a relatively cool environment.
Rotors having a large number of orifices, each having an _ sb/)i) .: . .. . . .. ... . . . . .
~L~7~
initial diameter of less than about 18 mils, are able to form primary fibers having diameters of less than 7 microns, e.g., 3 to 5 microns, if the relationship between the process variables are controlled in accordance with particular B 4a -sb/ ' ;~
~.~7~
1 relationships. It is even possible to produce sub-micron fibers using rotors whose orifice diameters are 2 mils or less.
With this arrangement, primary continuous fibers issue from the orifices, are twisted into a rope or strand by the spinning action of the rotor, and the rope or strand is pulled downward and wound into a package or further processed. Because of the relatively low temperature of the ambient air sur-rounding the rotor, at least the surfaces of the glass fibers are quickly cooled below the softening point of the glass. The continuous fibers are quickly cooled by the relatively cool environment surrounding the rotor. Unlike the prior art processes, the con-tinuous fibers are not heated, or their rate of cooling reduced, externally of the rotor to cause attenuation - in the present process.
The continuous fibers formed by the process and apparatus of the present invention have a narrower diameter distribution than the fibers produced by the prior art processes using hot gas blast attenuation~
For the purpose of this application, the term "average diameter" when referring to the fiber diameter is used in the sense of the conventional arithmetic or mean diameter obtained by averaging results of a microscopic determination.
Detc~iled Description of The Invention The drawing illustrates the preferred apparatus of the present invention. The apparatus is supported on conventional framework, but to better illustrate the apparatus the supporting framework has been omitted rom the drawing.
~' ~ - ,:
' ., ~ . ~. . . .
The apparatus comprises a drive shaft 32 which carries a spinner or rotor 34. The drive shaft is supported by, and rotatably mounted within, a tubular housing 36 by means of a pair of conventional bearing assemblies that are mounted in the tubular housing 36 in a conventional manner. The upper portion of the drive shaft 32 is provided with a sheave 40. The sheave is connected to a variable speed motor 42 or other con-ventional drive means by belt drive 44. Thus the rotation of the spinner 34 is affected by the motor 42 ich drives the drive shaft 32.
- The rotor 34 comprises a bottom wall 46, a peripheral wall ~7 containing orifices 48, and a re-inforcing upper wall ring 50 extending inwardly from the upper edge of the peripheral wall 47. The rotor is typically 12, 15, 18, 24 or more inches in interior diameter and has a centrally located aperture through which a threaded portion of the drive shaft 32 passes.
Smaller diameter rotors are operable, but are not de~irable because the output per unLt of height of the peripheral wall is undesirably low. A nut 52 on the threaded portion of the drive shaft plants the bottom wall of the rotor between itself and a shoulder on the drive shaft in a conventional manner. The bottom wall 46 forms the floor of the rotor. The lower edge portion of the peripheral wall 47 can be welded or otherwise affixed to the periphery of the bottom wall 46 and the upper edge portion of the peripheral wall 47 can be welded or otherwise secured to the upper reinforcing wall 50 which lends needed strength to the rotor when it is rotating at high speed at temperatures which tend -to ~, ' .
rw/ _ 6 _ -. . . . . . . . . .
~L~7~ ,y weaken the metal of the peripheral wall. The rotors ean be a one piece casting made by known casting techniques, such as investment casting, and this is preferred.
The peripheral wall 4~ of the rotor.is pro- -vided with a plurality of orifices 48 with the longitu-dinal axis of the orifices extending radially through the peripheral wall 47. In order to form continuous fibers having an average diameter of 3 to 5 microns by passing glass through the orifices at a rate of at least 600 lbs. per hr. and into a relatively cool environment, it is preferred to have at least 40,000 to 100,000 orifices in the peripheral wall with each orifice having an initial diameter ranging up to about 18 mils, preferably 12 mils, and most preferably up to about 10 mils or less. The spacing between orifices is typically about 36 mils, plus or minus about 10 mils.
Hot gasses from the burners 28, usually three such burners are sufficient, are directed onto the interior of the peripheral wall 47 of the rotor to maintain the peripheral wall at temperatures sufficient to maintain the glass at the proper viscosity to produce the desired fiber diameter in accordance with the present invention. For typical glass compositions presently being used, the interior peripharal wall is usually maintained at a temperature in the range of about 1700F. to 2100F~ ;
A combustible mixture is supplied to the burners 28 by conventional means.
The molten glass feed 26 flows rom a suitable source (not shown~ such as a forehearth, or oth~r con-rw/
- .
. ~
~7~
ventional glass melting and/or refining means, e.g. an electric furnace. The molten glass feed 26 enters the rotor at a point offset from its center. Due to the centrifugal forces generated by the rotation of the rotor, the molten glass flows toward the peripheral wall of the rotor and up the interior surface of the peripheral wall. When a sufficient head "h" has been built up on the interior wall of the rotor, and when the other operational and design parameters are properly controlled, the molten glass is forced through the orifices by the centrifugal force of the rotor to form contin-uous fibers having an average diameter of 7 microns or less.
The magnitude "h" can be controlled by controlling the rate of molten glass feed 26, the interior temperature of the rotor, and the rotational speed of the rotor.
A guard ring 54 surrounds the rotor for safety purposes and also to eliminate any disturbances in the fiber flow that might be caused by air currents in the plant.
The temperature of the environment within the guard member 54 is not critical so long as the temperature is below that that would be required to soften and thus attenuate the primary fibers. Normally some plant air is inherently drawn into the opening between guard 54 and the peripheral wall of the rotor 47 by the downward movement of the fibers.
Any heat c-ontained in the environment within ring 54 because of the continuous flow of hot fibers therethrough, is purely coincidental because the advantage of the present invention is thal: it is not necessary to heat this~environ-ment to a temperature sufficient to jrr:~
.
.
:' '. ~ : .
1 promote and permit attenuation of the fibers. Its sole function is to cool the continuous or long fibers.
In operation, the burners 28 heat both the bottom wall 46 and the interior of the peripheral wall
4% of the rotor to a temperature sufficient to main-tain the molten glass within the rotor 34 at the proper viscosity to produce fibers having the desired dia~
meter. While many glass compositions conventionally used to form glass fibers are suitable for use in the present invention, it is preferred to use a glass composition having a relatively low temperature ~ softening point and having suitable fiberizing visco-; sities at relatively low temperatures. Such a glass composition permits lower temperature rotor operation which extends the life of the rotor. The rotor life is dependent upon operating temperature, thus it is desirable to operate the rotor at as low as temperature as possible.
The continuous or long glass fibers 56 are collected at a point 58 located below the rotor 34 and are twisted into a rope or strand 60 by the spin-ning of the rotor. m e rope or strand is removed and collected or processed in conventional ways, e.g., see U.S. Patent No. 3,040,377.
The strand or rope product of the present in~ention has many uses, e.g., it can be used as a g caulking or sealing material, can be used in rein-forcing rovings, and can be chopped into lengths to make fiber mat or air blown insulation.
Cr:itical to the manufacture of continuous or very long fibers having diameters of less than 7 ;
microns by rotary fiberization without using hot gas ~--... . . .
;~r~
1 blast attenuation is the maintenance of particular relationships between the process design and opera-tional variables. These variables are glass viscosity, glass density, total flow of molten glass to and from the rotor, orifice diameter, rotor speed (RPM), thickness of the glass layer or head "h" on the interior of the peripheral wall of the rotor, thickness of the peripheral wall of the rotor (orifice length), interior diameter of the rotor, and the total number of the orifices in the peripheral wall of the rotor. Some of these variables are design parameters, e.g., orifice diameter, number of orifices, and rotor diameter. Other of the variables such as glass viscosity, glass density, rotor speed, and total flow rate of molten glass in the form of fibers from the rotor are operational parameters.
Because of the erosion caused by the molten - glass flowing through the orifices, the orifice dia-meter increases during the life of the rotor. To compensate for this change and to maintain the dia-meter of the fibers within the desired range, it becomes necessary during at least a portion of the rotor life to effectively decrease the height of the -peripheral wall of the rotor. Techniques for achieving this result will be described in detail later in the specification.
The particular relationships critical to the formation of small diameter primary fibers of no more than 7 microns are represented by the following three formulas:
(1) do = 2 / F
~ ~ pDfN
. ,~,,, ~ .
.
r~fphl 1/2 (2) do = .25 L - ~ d2 (3) h = 64 vFl 7r 3p2Df 2d~N --Where do = the average diameter of the fiber product;
= 3.14;
p = glass density at room temperature v = glass viscosity at operating temperature of the rotor;
F = total glass flow through the rotor per unit of time;
1 = thickness of the peripheral wall of the rotor;
D = interior diameter of the rotor;
- f = rotor speed;
d = diametar of the orifices; ;~
h = glass head on the wall of the rotor; and N = ~otal number of orifices in the rotor.
; In determining the design and operational parameters necessary to produce primary fibers having the desired - diameter without hot gas blast attenuation the following procedure is used.
First, a suitable glass composition is selected for use in the process. A viscosity versus temperature curve and the glass density for this glass are determined using well know techniques. Next, working with Formula (1) above, values for various parameters are selected on the basis of the results desired and the desired operating conditions.
For example, the desired diameter of the primary fibers, do, is selected. The glass density is known. A suitable rotor speed, f, is selected, the rate of primary fiber production, E', is selected, and finally the diameter of the rotor D, is selected. ~aving selected these parameters, ' sb/ o ~Q'7'~
Formula (1) above is then solved to determine the total number of holes or orifices, N, needed in the peripheral wall of the rotor. At this point, if the total number of holes, N, is :
L' ~
lla - ~:
sb/~
~o~
e~cessive to permit adequate spacin~ between orifices it will be necessary to go back and select another set of parameters, differing in at least one respect from the initial set select-ed. It will be readily apparent to one skilled in the art, having the benefit of the disclosure of Formula ~1), how to modify the selection of the parameters to produce a smaller N value.
Once a suitable N value has been determined, a rotor operating temperature is selected and the corresponding vis-cosity of the glass at that temperature is taken from theviscosity versus temperature curve. Then using Formula ~3) above, and after selecting a peripheral wall thickness which typically should fall between 50 and 250 mils, and selecting an "h" value which typically should fall between 1/32" and 1~2"
Formula (3) is solved to determine the orifice diameter, d.
For current rotor capabilities a peripheral wall thickness of about 124 mils and an "h" value of about 1/8 inch ~ 1/16 inch are preferred. This diameter should be less than 18 mils, preferably within the range of about 6 to 13 mils, and most preferably about 8 to 12 mils.
- As will be apparent to one skilled in the art from the above relationshlps there are several combinations of variables which will produce the desired primary fiber diameter. This feature offers flexibility to select specific values for those parameters which are the most critical to economical fiberization and to adjust the other parameters accordingly to produce the desired fiber diameter.
The following examples illustrate two embodiments utilizing the method and apparatus of the present invention.
The first embod:iment represents the preferred mode of oper_ ation and the second example represents one of numerous ~lternative embodiments that can be practiced.
- 12 _ jrr:~
.
~)7'~
EX~PLE 1 Three to five micron diameter fiber was produced using the apparatus illustrated in the drawing. The apparatus included an 18" diameter rotor having a peripheral wall height of 1 1/4" and a peripheral wall thickness of about 125 mils.
The rotor contained 50,000 orifices, each having an average diameter of about 10 mils. The initial rotor speed was set at 2200-2300 RPM and the molten glass feed was adjusted to 1000 lbs/hr, which was sufficient to produce an h value nominally of 1/8 inch and which varied between 1/16 and 3/16 inch. The burners heating the interior of the rotor were - adjusted to produce an initial rotor interior temperature of about 1850-1900F.
The glass composition used in this example contain-ed on an oxide weight basis, 55.1% silica, 17.1~ soda, 13%
lime, 9.3% B203, 3.5~ alumina, .9% potash, .6% magnesia, .1% iron oxide and .1% sulphur trioxide with the remainder being made up of traces of other oxide impurities. ~his glass has a glass density of 2.G gm/cc, a softening point of 1217F, and a viscosity at 1850-1900F of about 500-325 poise respectively and the rotor was made of an alloy typically containing about 0.28% carbon, 27.8% chromium, 2.5% nickel, 5.8% molybdenum, 1.8% iron,and the balance ;
cobalt, on a weight basis.
Operating under these design and operational parameters this apparatus and process produced about . ' :' - 13 - ~
. ' , .
jrr~ <-- ~
1 1000 lbs. per hour of fi~er strand with the individual fibers having an average diameter in the range of 3-5 microns.
Using the same glass composition and rotor material as described in Example 1, a 15" diameter rotor having a 2" high peripheral wall 125 mils thick and con-taining 50,000 orifices of 10 mil diameter produced essentially the same product and at essentially the same rate as the apparatus and process of Example 1. It was necessary to increase the initial rotor speed to a value in the range of about 2800-3000 RPM but the rotor interior temperature, h value, glass density, and vis-cosity and molten glass flow rate were at the same values used in Example 1.
In selecting the rotor diameter, the rotor peripheral wall thickness, and the materials to be used in making the rotor for use in the present invention several factors must be considered. First, as evidenced from Formulas (1) and ~3) above, the rotor diameter can be adjusted to allow adjustment in other operational parameters. Second, as the rotor diameter is increased the area of the peripheral wall also increases if the peripheral wall height is not changed. Thus, the height of the peripheral wall can be decreased as the diameter increases, to hold the area constant. This factor is very important because as the height of the peripheral wall increasles there is more of a tendency, due to the centrifugal forces developed during operation and the high temperature at which the rotor must operate, for the peripheral wall to deform outwardly at its center.
When this happens the orifice diameters change, the ,~
~~
''' "
~ 07i~
1 "h" value no longer remains constant, and the useful life of the rotor is essentially endecl. Thus, it is desirable to keep the height of the peripheral wall as low as possible.
In selecting the thickness of the peripheral wall one must balance the strength that increased thick-ness provides with the increased mass that accompanies an increased thickness. An increased peripheral wall mass increases the tendency for the peripheral wall to warp or deform at operational speeds and temperatures.
A suitable operating range for the peripheral wall thick-ness, with the alloy disclosed in Example 1, has been found to be in a range of about 50-250 mils. A peri-pheral wall thickness of less than about 50 mils does not produce the desired structural strength in the rotor, and a peripheral wall thickness greater than about 250 mils is not only difficult to penetrate by conventional laser drilling techniques, or other equi-; valent techniques of forming the orifices, but also .
adds excessive weight or mass onto the peripheral wall, reducing its ability to maintain structural integrity at operating conditions.
The preferred alloy for use in making the rotor is disclosed in Example 1 and represents a balance between high temperature structural strength and resis-tance to erosion and corrosion by the molten glass passing through the orifices. Other alloys are avail-able that have greater resistance to high temperature creep or deformation under stress. While rotors of ~;
such alloys could be operated at higher RPMs, higher temperatures, and/or greater peripheral wall heights without deformation, the orifices were eroded faster , ~ ~ j .
< ~
.. ' ' ' ~ ' .. , . . , , . - . ~ . . . , : .
~)774~
1 by the glass flow through the orifices, thus reducing the life of the rotor. Some alloys tested had greater resistance to erosion by the molten glass, but their creep resistance was insufficient to resist the deformation tendencies at operating temperatures for sufficient periods of time.
The design and operational parameters selected according to the above described procedures are initial parameters. As mentioned earlier, one of the design parameters, orifice diameter, changes as the rotor life increases, and thus one or more other parameters must be ; changed accordingly to compensate for the change in the orifice diameter in order to retain the desired diameter in the fiber produced. Formula (2) above is useful in determining which parameter(s) should be changed, and how much they should be changed, to compensate ~or the change in the orifice diameter, d. Looking at Formula (2) it can be seen that as d increases it is necessary to either decrease the rotor speed and/or to increase the viscosity of the glass in order to keep do constant.
The glass density and the thickness of the peripheral wall are not adaptable to modification during the operation of the rotor. To compensate for an increasing orifice diameter during the life of the rotor, it is preferred to first increase the glass viscosity by lowering the temperature on the interior of the rotor, to maintain a constant ~iber diameter in the fiber product, until that temperature is reached which is just above a temperature that would cause devitrification problems ;
in the molten glass in the rotor, i.e., just above the liquidus temperature. Once that point is reached the rotor speed is increased to compensate for the ., .. . ,. . -... ~
~o~
1 reduction in the number of holes emitting primary filaments, N, due to increasing d value (See Formula 1).
The "h" value must be maintained above a minimum value of about 1/32 inch to maintain the desired fiber diameter.
When a maximum practical rotor speed is reached it is then necessary to put on a new rotor in order to continue to make primary fibers having the desired diameter of 7 microns or less. Experience has shown that, when the process parameters are so adj~lsted to produce a maximum rotor life, fibers are being formed from the orifices in only about the lower one-half of the peripheral wall during the final stage of the rotor life. Thus during the latter portion of the rotor life the effective height of the peripheral wall is reduced.
The fibers produced by the present invention are not all continuous since some o~ the fibers break off in the bending path and during twisting. However, the major portion of the broken fibers are long, com- -pared to the lengths of conventional staple glass fibers, e.g., at least about 5 times as long. Because of the extreme difficulty of isolating individual fibers without causing additional breaks the average lengths of the fibers is not known.
` In describing the invention certain embodiments have been used to illustrate the invention and the practice thereof. However, the invention is not limited to these specific embodiments as other embodiments and modifications within the spirit of the invention will ~ -readily occur to those skilled in the art on reading this specification. The invention is thus not intended to be limited to the specific emhodiments disclosed, but instead it is to be limited only by the claims appended hereto.
``. '.. ,7 --~ .. ... .
- . . . .
.
meter. While many glass compositions conventionally used to form glass fibers are suitable for use in the present invention, it is preferred to use a glass composition having a relatively low temperature ~ softening point and having suitable fiberizing visco-; sities at relatively low temperatures. Such a glass composition permits lower temperature rotor operation which extends the life of the rotor. The rotor life is dependent upon operating temperature, thus it is desirable to operate the rotor at as low as temperature as possible.
The continuous or long glass fibers 56 are collected at a point 58 located below the rotor 34 and are twisted into a rope or strand 60 by the spin-ning of the rotor. m e rope or strand is removed and collected or processed in conventional ways, e.g., see U.S. Patent No. 3,040,377.
The strand or rope product of the present in~ention has many uses, e.g., it can be used as a g caulking or sealing material, can be used in rein-forcing rovings, and can be chopped into lengths to make fiber mat or air blown insulation.
Cr:itical to the manufacture of continuous or very long fibers having diameters of less than 7 ;
microns by rotary fiberization without using hot gas ~--... . . .
;~r~
1 blast attenuation is the maintenance of particular relationships between the process design and opera-tional variables. These variables are glass viscosity, glass density, total flow of molten glass to and from the rotor, orifice diameter, rotor speed (RPM), thickness of the glass layer or head "h" on the interior of the peripheral wall of the rotor, thickness of the peripheral wall of the rotor (orifice length), interior diameter of the rotor, and the total number of the orifices in the peripheral wall of the rotor. Some of these variables are design parameters, e.g., orifice diameter, number of orifices, and rotor diameter. Other of the variables such as glass viscosity, glass density, rotor speed, and total flow rate of molten glass in the form of fibers from the rotor are operational parameters.
Because of the erosion caused by the molten - glass flowing through the orifices, the orifice dia-meter increases during the life of the rotor. To compensate for this change and to maintain the dia-meter of the fibers within the desired range, it becomes necessary during at least a portion of the rotor life to effectively decrease the height of the -peripheral wall of the rotor. Techniques for achieving this result will be described in detail later in the specification.
The particular relationships critical to the formation of small diameter primary fibers of no more than 7 microns are represented by the following three formulas:
(1) do = 2 / F
~ ~ pDfN
. ,~,,, ~ .
.
r~fphl 1/2 (2) do = .25 L - ~ d2 (3) h = 64 vFl 7r 3p2Df 2d~N --Where do = the average diameter of the fiber product;
= 3.14;
p = glass density at room temperature v = glass viscosity at operating temperature of the rotor;
F = total glass flow through the rotor per unit of time;
1 = thickness of the peripheral wall of the rotor;
D = interior diameter of the rotor;
- f = rotor speed;
d = diametar of the orifices; ;~
h = glass head on the wall of the rotor; and N = ~otal number of orifices in the rotor.
; In determining the design and operational parameters necessary to produce primary fibers having the desired - diameter without hot gas blast attenuation the following procedure is used.
First, a suitable glass composition is selected for use in the process. A viscosity versus temperature curve and the glass density for this glass are determined using well know techniques. Next, working with Formula (1) above, values for various parameters are selected on the basis of the results desired and the desired operating conditions.
For example, the desired diameter of the primary fibers, do, is selected. The glass density is known. A suitable rotor speed, f, is selected, the rate of primary fiber production, E', is selected, and finally the diameter of the rotor D, is selected. ~aving selected these parameters, ' sb/ o ~Q'7'~
Formula (1) above is then solved to determine the total number of holes or orifices, N, needed in the peripheral wall of the rotor. At this point, if the total number of holes, N, is :
L' ~
lla - ~:
sb/~
~o~
e~cessive to permit adequate spacin~ between orifices it will be necessary to go back and select another set of parameters, differing in at least one respect from the initial set select-ed. It will be readily apparent to one skilled in the art, having the benefit of the disclosure of Formula ~1), how to modify the selection of the parameters to produce a smaller N value.
Once a suitable N value has been determined, a rotor operating temperature is selected and the corresponding vis-cosity of the glass at that temperature is taken from theviscosity versus temperature curve. Then using Formula ~3) above, and after selecting a peripheral wall thickness which typically should fall between 50 and 250 mils, and selecting an "h" value which typically should fall between 1/32" and 1~2"
Formula (3) is solved to determine the orifice diameter, d.
For current rotor capabilities a peripheral wall thickness of about 124 mils and an "h" value of about 1/8 inch ~ 1/16 inch are preferred. This diameter should be less than 18 mils, preferably within the range of about 6 to 13 mils, and most preferably about 8 to 12 mils.
- As will be apparent to one skilled in the art from the above relationshlps there are several combinations of variables which will produce the desired primary fiber diameter. This feature offers flexibility to select specific values for those parameters which are the most critical to economical fiberization and to adjust the other parameters accordingly to produce the desired fiber diameter.
The following examples illustrate two embodiments utilizing the method and apparatus of the present invention.
The first embod:iment represents the preferred mode of oper_ ation and the second example represents one of numerous ~lternative embodiments that can be practiced.
- 12 _ jrr:~
.
~)7'~
EX~PLE 1 Three to five micron diameter fiber was produced using the apparatus illustrated in the drawing. The apparatus included an 18" diameter rotor having a peripheral wall height of 1 1/4" and a peripheral wall thickness of about 125 mils.
The rotor contained 50,000 orifices, each having an average diameter of about 10 mils. The initial rotor speed was set at 2200-2300 RPM and the molten glass feed was adjusted to 1000 lbs/hr, which was sufficient to produce an h value nominally of 1/8 inch and which varied between 1/16 and 3/16 inch. The burners heating the interior of the rotor were - adjusted to produce an initial rotor interior temperature of about 1850-1900F.
The glass composition used in this example contain-ed on an oxide weight basis, 55.1% silica, 17.1~ soda, 13%
lime, 9.3% B203, 3.5~ alumina, .9% potash, .6% magnesia, .1% iron oxide and .1% sulphur trioxide with the remainder being made up of traces of other oxide impurities. ~his glass has a glass density of 2.G gm/cc, a softening point of 1217F, and a viscosity at 1850-1900F of about 500-325 poise respectively and the rotor was made of an alloy typically containing about 0.28% carbon, 27.8% chromium, 2.5% nickel, 5.8% molybdenum, 1.8% iron,and the balance ;
cobalt, on a weight basis.
Operating under these design and operational parameters this apparatus and process produced about . ' :' - 13 - ~
. ' , .
jrr~ <-- ~
1 1000 lbs. per hour of fi~er strand with the individual fibers having an average diameter in the range of 3-5 microns.
Using the same glass composition and rotor material as described in Example 1, a 15" diameter rotor having a 2" high peripheral wall 125 mils thick and con-taining 50,000 orifices of 10 mil diameter produced essentially the same product and at essentially the same rate as the apparatus and process of Example 1. It was necessary to increase the initial rotor speed to a value in the range of about 2800-3000 RPM but the rotor interior temperature, h value, glass density, and vis-cosity and molten glass flow rate were at the same values used in Example 1.
In selecting the rotor diameter, the rotor peripheral wall thickness, and the materials to be used in making the rotor for use in the present invention several factors must be considered. First, as evidenced from Formulas (1) and ~3) above, the rotor diameter can be adjusted to allow adjustment in other operational parameters. Second, as the rotor diameter is increased the area of the peripheral wall also increases if the peripheral wall height is not changed. Thus, the height of the peripheral wall can be decreased as the diameter increases, to hold the area constant. This factor is very important because as the height of the peripheral wall increasles there is more of a tendency, due to the centrifugal forces developed during operation and the high temperature at which the rotor must operate, for the peripheral wall to deform outwardly at its center.
When this happens the orifice diameters change, the ,~
~~
''' "
~ 07i~
1 "h" value no longer remains constant, and the useful life of the rotor is essentially endecl. Thus, it is desirable to keep the height of the peripheral wall as low as possible.
In selecting the thickness of the peripheral wall one must balance the strength that increased thick-ness provides with the increased mass that accompanies an increased thickness. An increased peripheral wall mass increases the tendency for the peripheral wall to warp or deform at operational speeds and temperatures.
A suitable operating range for the peripheral wall thick-ness, with the alloy disclosed in Example 1, has been found to be in a range of about 50-250 mils. A peri-pheral wall thickness of less than about 50 mils does not produce the desired structural strength in the rotor, and a peripheral wall thickness greater than about 250 mils is not only difficult to penetrate by conventional laser drilling techniques, or other equi-; valent techniques of forming the orifices, but also .
adds excessive weight or mass onto the peripheral wall, reducing its ability to maintain structural integrity at operating conditions.
The preferred alloy for use in making the rotor is disclosed in Example 1 and represents a balance between high temperature structural strength and resis-tance to erosion and corrosion by the molten glass passing through the orifices. Other alloys are avail-able that have greater resistance to high temperature creep or deformation under stress. While rotors of ~;
such alloys could be operated at higher RPMs, higher temperatures, and/or greater peripheral wall heights without deformation, the orifices were eroded faster , ~ ~ j .
< ~
.. ' ' ' ~ ' .. , . . , , . - . ~ . . . , : .
~)774~
1 by the glass flow through the orifices, thus reducing the life of the rotor. Some alloys tested had greater resistance to erosion by the molten glass, but their creep resistance was insufficient to resist the deformation tendencies at operating temperatures for sufficient periods of time.
The design and operational parameters selected according to the above described procedures are initial parameters. As mentioned earlier, one of the design parameters, orifice diameter, changes as the rotor life increases, and thus one or more other parameters must be ; changed accordingly to compensate for the change in the orifice diameter in order to retain the desired diameter in the fiber produced. Formula (2) above is useful in determining which parameter(s) should be changed, and how much they should be changed, to compensate ~or the change in the orifice diameter, d. Looking at Formula (2) it can be seen that as d increases it is necessary to either decrease the rotor speed and/or to increase the viscosity of the glass in order to keep do constant.
The glass density and the thickness of the peripheral wall are not adaptable to modification during the operation of the rotor. To compensate for an increasing orifice diameter during the life of the rotor, it is preferred to first increase the glass viscosity by lowering the temperature on the interior of the rotor, to maintain a constant ~iber diameter in the fiber product, until that temperature is reached which is just above a temperature that would cause devitrification problems ;
in the molten glass in the rotor, i.e., just above the liquidus temperature. Once that point is reached the rotor speed is increased to compensate for the ., .. . ,. . -... ~
~o~
1 reduction in the number of holes emitting primary filaments, N, due to increasing d value (See Formula 1).
The "h" value must be maintained above a minimum value of about 1/32 inch to maintain the desired fiber diameter.
When a maximum practical rotor speed is reached it is then necessary to put on a new rotor in order to continue to make primary fibers having the desired diameter of 7 microns or less. Experience has shown that, when the process parameters are so adj~lsted to produce a maximum rotor life, fibers are being formed from the orifices in only about the lower one-half of the peripheral wall during the final stage of the rotor life. Thus during the latter portion of the rotor life the effective height of the peripheral wall is reduced.
The fibers produced by the present invention are not all continuous since some o~ the fibers break off in the bending path and during twisting. However, the major portion of the broken fibers are long, com- -pared to the lengths of conventional staple glass fibers, e.g., at least about 5 times as long. Because of the extreme difficulty of isolating individual fibers without causing additional breaks the average lengths of the fibers is not known.
` In describing the invention certain embodiments have been used to illustrate the invention and the practice thereof. However, the invention is not limited to these specific embodiments as other embodiments and modifications within the spirit of the invention will ~ -readily occur to those skilled in the art on reading this specification. The invention is thus not intended to be limited to the specific emhodiments disclosed, but instead it is to be limited only by the claims appended hereto.
``. '.. ,7 --~ .. ... .
- . . . .
.
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of producing continuous or long fibers having an average diameter of less than about 7 microns from molten glass material comprising: introducing said molten material at a rate of hundreds of pounds per hour into a rotating rotor internal of a peripheral wall of said rotor, said peripheral wall containing orifices, having a diameter no greater than about 18 mils, passing said molten material through said orifices, controlling relationships of design and operational parameters consist-ing essentially of density, viscosity and rate of flow through said rotor of said molten material: peripheral wall thickness, interior diameter, and rotational speed of the rotor, number and diameter of orifices in said rotor: and head of molten material on the interior surface of the peripheral wall of said rotor so as to form fibers having an average diameter of no more than about 7 microns without using additional attenuation means externally of the rotor.
2. A method as defined in Claim 1 wherein there are at least about 40,000 orifices, and the diameter of said orifices is no greater than about 12 mils.
3. A method as defined in Claim 2 wherein the diameter of said orifices is no greater than about 10 mils.
4. A method as defined in Claim 2 wherein said molten glass material is fed to said rotor at a rate of at least about 600 pounds per hour.
5. A method as defined in Claim 2 wherein said rate is at least abour 1,000 pounds per hour.
6. A method as defined in Claim 4 wherein the diameter of said rotor is at least about 15 inches.
7. A method as defined in Claim 5 wherein the diameter of said rotor is at least about 18 inches.
8. A method as defined in Claim 1 wherein the design and operational parameters of the process, and any apparatus used therewith, are varied to maintain the rela-tionships represented by the following three formulas:
(1) (2) (3) Where do equals the average diameter of the continuous or long fiber;
.pi. = 3.14;
p = glass density at room temperature;
v = glass viscosity at operating temperature of the rotor;
F = total glass flow through the rotor per unit of time;
1 = thickness of the peripheral wall of the rotor;
D = interior diameter of the rotor;
f = rotor speed;
d = diameter of the orifices;
h = glass head on the wall of the rotor, and N = total number of orifices in the rotor.
(1) (2) (3) Where do equals the average diameter of the continuous or long fiber;
.pi. = 3.14;
p = glass density at room temperature;
v = glass viscosity at operating temperature of the rotor;
F = total glass flow through the rotor per unit of time;
1 = thickness of the peripheral wall of the rotor;
D = interior diameter of the rotor;
f = rotor speed;
d = diameter of the orifices;
h = glass head on the wall of the rotor, and N = total number of orifices in the rotor.
9. A method as defined in Claim 8 wherein the diameter of said orifices is no greater than about 12 mils
10. A method as defined in Claim 8 wherein the diameter of said orifices is no greater than abour 10 mils.
11. A method as defined in Claim 10 wherein do is no greater than about 5 microns.
12. A method as defined in Claim 11 wherein the diameter of said rotor is at least about 15 inches, the peripheral wall thickness is between 50 and 250 mils, the rotor contains at least about 50,000 orifices, and the rotor speed is between about 2,800 and about 3,000 RPM.
13. A method as defined in Claim 11 wherein said rotor diameter is at least about 18 inchres, the peripheral wall thickness is between 50 and 250 mils, the rotor contains at least about 50,000 orifices, and said rotor speed is in a range of about 2,200 - 2,300 RPM.
14. A method as defined in claim 8 wherein during the life of the rotor and as the diameter of the orifices increase due to wear the viscosity of the molten glass material is gradually lowered by lowering the rotor temperature of the interior of the rotor to maintain do essentially constant, and when a glass temperature is reached that is just above a glass temperature that would cause devitrification problems in the molten glass, the rotor speed is gradually increased to maintain do constant.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US54409475A | 1975-01-27 | 1975-01-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1074118A true CA1074118A (en) | 1980-03-25 |
Family
ID=24170723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA224,807A Expired CA1074118A (en) | 1975-01-27 | 1975-04-16 | Method and apparatus for eliminating external hot gas attenuation with rotary fiberization of glass |
Country Status (16)
| Country | Link |
|---|---|
| JP (1) | JPS5199127A (en) |
| AU (1) | AU504579B2 (en) |
| BE (1) | BE837681A (en) |
| BG (1) | BG29720A3 (en) |
| CA (1) | CA1074118A (en) |
| DE (1) | DE2602902A1 (en) |
| FI (1) | FI760192A (en) |
| FR (1) | FR2298517A1 (en) |
| GB (1) | GB1528822A (en) |
| HU (1) | HU175762B (en) |
| IN (1) | IN144524B (en) |
| IT (1) | IT1053390B (en) |
| MX (1) | MX3495E (en) |
| RO (1) | RO72105A (en) |
| SE (1) | SE7600755L (en) |
| ZA (1) | ZA7679B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5326241A (en) * | 1991-04-25 | 1994-07-05 | Schuller International, Inc. | Apparatus for producing organic fibers |
| US6227009B1 (en) * | 1998-12-14 | 2001-05-08 | Michael John Cusick | Method of making long, fine diameter glass fibers and products made with such glass fibers |
| US20070000286A1 (en) * | 2005-07-01 | 2007-01-04 | Gavin Patrick M | Fiberizing spinner for the manufacture of low diameter, high quality fibers |
| MX2009010076A (en) | 2007-03-21 | 2009-11-11 | Owens Corning Intellectual Cap | Rotary fiberizer. |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL157880B (en) * | 1972-12-22 | 1978-09-15 | Johns Manville | METHOD AND DEVICE FOR MANUFACTURING STACKED FIBERS. |
-
1975
- 1975-04-16 CA CA224,807A patent/CA1074118A/en not_active Expired
-
1976
- 1976-01-06 ZA ZA00760079A patent/ZA7679B/en unknown
- 1976-01-07 GB GB462/76A patent/GB1528822A/en not_active Expired
- 1976-01-08 IN IN46/CAL/76A patent/IN144524B/en unknown
- 1976-01-09 AU AU10161/76A patent/AU504579B2/en not_active Expired
- 1976-01-19 BE BE163604A patent/BE837681A/en not_active IP Right Cessation
- 1976-01-20 IT IT47709/76A patent/IT1053390B/en active
- 1976-01-26 FR FR7602014A patent/FR2298517A1/en active Granted
- 1976-01-26 HU HU76JO229A patent/HU175762B/en unknown
- 1976-01-26 MX MX100265U patent/MX3495E/en unknown
- 1976-01-26 SE SE7600755A patent/SE7600755L/en unknown
- 1976-01-27 JP JP51007206A patent/JPS5199127A/ja active Pending
- 1976-01-27 RO RO7684622A patent/RO72105A/en unknown
- 1976-01-27 BG BG032198A patent/BG29720A3/en unknown
- 1976-01-27 DE DE19762602902 patent/DE2602902A1/en not_active Withdrawn
- 1976-01-27 FI FI760192A patent/FI760192A/fi not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| AU1016176A (en) | 1977-07-14 |
| ZA7679B (en) | 1976-12-29 |
| FI760192A (en) | 1976-07-28 |
| AU504579B2 (en) | 1979-10-18 |
| BE837681A (en) | 1976-07-19 |
| JPS5199127A (en) | 1976-09-01 |
| DE2602902A1 (en) | 1976-07-29 |
| FR2298517B1 (en) | 1982-05-21 |
| GB1528822A (en) | 1978-10-18 |
| MX3495E (en) | 1980-12-17 |
| BG29720A3 (en) | 1981-01-15 |
| IN144524B (en) | 1978-05-13 |
| SE7600755L (en) | 1976-07-27 |
| HU175762B (en) | 1980-10-28 |
| RO72105A (en) | 1982-05-10 |
| IT1053390B (en) | 1981-08-31 |
| FR2298517A1 (en) | 1976-08-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4058386A (en) | Method and apparatus for eliminating external hot gas attenuation in the rotary fiberization of glass | |
| AU664852B2 (en) | Method and apparatus for manufacturing mineral wool, and mineral wool produced thereby | |
| CA2121573C (en) | Method and apparatus for the production of mineral wool, and mineral wool thereby produced | |
| US4759974A (en) | Glass fiberization | |
| US7314557B2 (en) | Method and device for forming mineral wool | |
| CA1136165A (en) | Glass composition and fibers | |
| US5554324A (en) | Method for producing mineral wool | |
| FI95124B (en) | Method and apparatus for making fibers | |
| KR900009019B1 (en) | Apparatus for Making Fibers from Thermoplastics | |
| US4246017A (en) | Method and apparatus for forming mineral fibers | |
| CA1074118A (en) | Method and apparatus for eliminating external hot gas attenuation with rotary fiberization of glass | |
| US4756732A (en) | Glass fiberization method | |
| US4759785A (en) | Glass fiberization method | |
| KR20210060452A (en) | Alloys for fiber-forming plates | |
| US4812151A (en) | Viscosity control in the manufacture of mineral fibers | |
| BG62131B1 (en) | Manufacture of vitreous fibre products | |
| US4146377A (en) | Method of using bushing environmental control in glass fiber forming | |
| RU2452696C2 (en) | Method for producing fibres from mine rock, and "kibol-granula module" plant for its implementation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |