JPS596822B2 - Separation and formation method of molten glass cone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for forming a molten glass cone from overflowing and sticky molten glass on the bottom surface of a nozzle plate in glass fiber spinning using a tip nozzle. The present invention relates to a method for separating and forming a molten glass cone in each tip nozzle by application of a narrow gas flux from molten glass that overflows and sticks to the gap between the tip nozzles upon cutting of the fibers therein.

The spinning furnace for producing glass fibers, which is currently most commonly used, is equipped with a tip nozzle plate at the bottom that has many tip nozzles protruding from the plate surface, and between the rows of these tip nozzles, This is a bushing in which cooling fins, which are plate-shaped cooling means, are inserted and arranged every second row.

In the industrial continuous production of glass fiber using such a bushing with cooling fins, for stable spinning of fibers, it is necessary to use a conventional nozzle in which cooling fins are arranged between rows of tip nozzles, for example, in two rows. In the plate, there is a distance of 1.5 to 2.0 shoulders between the tip nozzle rows in which cooling fins are not inserted or between adjacent tip nozzles within the row, as the distance between the tip outer walls of the tip nozzles. Similarly, the distance between adjacent tip nozzles between the rows of tip nozzles sandwiching cooling fins is 4.0 to 4.0 to the outer wall of the nozzle tips.
It is said that a distance of 8.0 shoulder m is required, and thus the number of tip nozzles that one nozzle plate can have is limited to a maximum of about 1,000, mainly due to the need to consider the strength characteristics of the nozzle plate at the spinning temperature. has been done.

However, some bushings are designed to allow two such nozzle plates to be connected and held through appropriate reinforcement and support means. When spinning glass fiber using a bushing equipped with a tip nozzle plate with cooling fins, at the start of spinning the bushing is electrically resistively heated to gradually raise the temperature of the molten glass inside the bushing at a relatively low temperature or high temperature. The viscous molten glass is forced into a relatively high temperature, low viscosity spinning temperature and viscosity state in a controlled manner, so that the molten glass flowing out of the tip nozzle forms a long cone and naturally falls. Generally speaking, molten glass does not overflow into the gap between the tip nozzles, but if temperature control is incorrect and the temperature is raised rapidly, resulting in a sudden drop in glass viscosity, molten glass may overflow between the tip nozzles and stick. There is.

Such overflow and sticking of molten glass can occur more frequently when glass fibers are cut during spinning. This is because during spinning, both the nozzle plate and the molten glass are in a high temperature state, and the low-viscosity molten glass has a strong tendency to wet the nozzle plate, and the affinity between the two is also large. The frequency of overflowing and sticking of molten glass becomes as high as possible as the density of the tip nozzles in the nozzle plate increases and the space between the nozzles becomes narrower, and at the same time, recovery from it becomes difficult.

For example, in the case of the above-mentioned conventional tip nozzle plate with cooling fins, spinning starts when the distance between the tip outer walls between rows of tip nozzles in which cooling fins are not inserted or between adjacent tip nozzles in a row becomes approximately 1.57n or less. Although the time is controllable, spillover occurs very frequently during fiber cutting during spinning, especially when the distance is less than about 0.67 ftR.
In small spaces, such as 0.310 t, overflows almost inevitably occur, and in the case of such close-contact nozzles these overflows cannot be recovered in a short time acceptable for continuous operation. That is, during spinning, the molten glass itself is inherently prone to overflowing as described above, but if the space between the tip nozzles is small at this time, the surface formed at the tip of the nozzle as a result of fiber cutting. The beads of molten glass swelled under tension merge with surrounding molten glass cones forming beads or fibers, and eventually the molten glass crawls up the wall of the tip nozzle and fills the nozzle gap. When the tip nozzle is embedded, it overflows, sticks, spreads to the surrounding area, and also adheres to the cooling fins.

In such a state, it is practically impossible to remove the overflowing molten glass in a short time while maintaining the spinning conditions, and in order to remove it and restore the spinning condition, it is necessary to start spinning. have to start over from the beginning. That is, the temperature of the entire bushing is lowered, the temperature of the nozzle plate is lowered by 20 to 50 degrees Celsius from the set temperature of the protrusion leg, the cooling fin is removed, the overflowing glass is picked out with something like a thin platinum rod and cleaned, and the cooling fin is removed. After repositioning, the spinning start operation must be performed again. This operation of removing the spilled glass and starting the spinning process is carried out under high temperature radiant heat from the bushing, in most cases at least about 3.
It takes a long time, from 0 minutes to 90 minutes in some cases. This is an operating condition that is completely unacceptable in the continuous production of glass fibers. This is the main reason why high density tip nozzle plates cannot be used in continuous production of glass fibers. The present inventor has discovered that the molten glass that overflows and sticks to the gap between the tip nozzles in the tip nozzle plate with cooling fins can be removed without changing the spinning conditions by locally applying a gas flux thereto. In particular, the tip nozzle is formed to protrude closely beyond the conventional range, so that the molten glass cone can be easily removed without removing it, and at the same time the molten glass cone can be easily separated and reformed from its overflowing molten glass. Even for such overflowing molten glass in a tip nozzle plate with cooling fins, the molten glass can be easily removed and melted in an industrially acceptable short time while maintaining the spinning conditions without removing the cooling fins. The present invention was completed by discovering that it can be separated and formed into glass cones.

In this way, the present invention provides a method for spinning glass fibers using a bushing equipped with a tip nozzle plate at the bottom, in which cooling fins are inserted and arranged between the rows of tip nozzles. It is an object of the present invention to provide a method for removing cooling fins without removing them while maintaining spinning conditions, and at the same time separating and forming a molten glass cone in the tip nozzle.

Another object of the present invention is to provide a bushing with a tip nozzle plate at the bottom, in which cooling fins are inserted and arranged between the rows of tip nozzles, and the tip nozzles are protruded and formed more closely than the conventional range. During spinning, molten glass spilling into the gap between the tip nozzles and sticking is removed by application of a gas flux in an industrially acceptable time while maintaining spinning conditions and without removing the cooling fins; It is an object of the present invention to provide a method for simultaneously separating and forming a molten glass cone in said tip nozzle, thus making it possible to use said high-density tip nozzle plate in continuous spinning of glass fibers.

The method of separating and forming a molten glass cone from overflowing and sticky molten glass according to the present invention to achieve the above object basically consists of inserting a cooling finger between rows of tip nozzles and placing a tip nozzle plate at the bottom. When spinning glass fibers using bushings, the sticky molten glass that overflows into the gap between the tip nozzles at the start of spinning or when the glass fibers are cut is slowly pulled downward, substantially causing the sticky molten glass to overflow and stick to the gap between the tip nozzles. A narrow gas flux that can locally exert a wind pressure sufficient to impart viscosity to the molten glass that is sufficient to transmit the above-mentioned tensile force without causing the molten glass to lose its fluidity. It is characterized by directing.

In the above-mentioned invention, the tip nozzle means a tip-shaped nozzle that projects and is formed on the nozzle plate, and each tip nozzle has an orifice passing through its center and penetrating the nozzle plate for outflow of molten glass. It is formed. In the present invention, the tip nozzles can be formed in the nozzle plate in the usual space or in close contact beyond the usual space, and the invention can be used particularly advantageously for the latter close-fitting tip nozzle. Commonly used cooling fins are inserted and arranged between the rows of tip nozzles. Cooling fins can be arranged every other row between the rows of tip nozzles, but usually they are arranged every other row. A typical bushing with a cooling finned tip nozzle plate on the bottom is shown in front and side cross-sectional views, respectively, in FIGS. 1 and 2, mounted to the bottom of the forehearth. In FIGS. 1 and 2, reference numeral 1 denotes a part of the bottom of a forearth made of refractory bricks, in which a passage 2 for molten glass to flow into the bushing is formed.

The bushing 3 is attached so that its upper opening is aligned with the flow path 2. The bushing 3 has a front plate 4 and a rear plate 4.
', two side plates 5, 5' and a nozzle plate 6.

Each of these elements is generally composed of an alloy containing platinum as a main component, such as a platinum-rhodium alloy or a monoplatinum-palladium alloy. Inside the bushing 3, a screen plate 7 for heating, evaporating, or distributing molten glass is disposed transversely, and terminals 8, 8' for supplying power to the bushing are attached to both side plates 5, 5'. It is being The outer periphery of the bushing 3 is surrounded by a refractory castable 9 and supported by a furnace frame 10 to keep the bushing warm. A flange 11 connected to the upper end of the wall plate of the bushing 3 extends on the upper surface of the refractory castable 9, and the bushing 3 surrounded by the castable caster 9 is attached to the forearth 1 with this flange 11 and a blanket 12 as a cushion sealing material. The furnace frame 10 is mounted by supporting the furnace frame 10 under the refractory bricks of the forehearth 1 using appropriate supporting and mounting means.

A water cooling coil 13 is located inside the castable under the flange 11.
is embedded to circulate cooling water to prevent molten glass from leaking from the contact surface.
Although not shown, a thermocouple is welded to the front plate 4 of the bushing 3, and the bushing is connected through a terminal 8 from a power supply system (not shown) to make the bushing 3 generate resistance heat according to the temperature detected by the thermocouple. 3 and exits from the terminal 8', the molten glass 14 in the bushing is controlled and maintained at a constant spinning temperature.

A large number of tip nozzles 15 are formed protruding from the nozzle plate 6, and the molten glass 14 at a constant spinning temperature in the bushing flows out through the orifice bored through the nozzle plate 6 and the tip nozzles 15 by the head pressure. The fibers 16 are then drawn and fiberized while forming a molten glass cone at the nozzle tip by a conventional mechanical tensioning mechanism (not shown), such as a winder or a roller.

Between the rows of tip nozzles on the tip nozzle plate 6 are two
Cooling fins 17 are inserted and arranged in alternate rows.

The cooling fins 17 are generally made of a good thermal conductor such as silver or platinum, and function to absorb radiant heat from the tip nozzle 15 and the molten glass cone formed at its tip and cool it. The cooling fins 17 generally have a simple plate-like structure, but various other structures are known, such as a hollow plate structure through which circulating water passes, any of which can be used in the present invention. Each cooling fin 17 is connected at one end to a water cooling block 18, which is supported and fixed by suitable means. The block 18 has a water conduit passage inside, through which cooling water supplied from a water supply conduit 19 at one end and discharged from a drainage conduit 20 at the other end passes, and the heat absorbed by the cooling fins 17 is transferred to this water. It is becoming more and more popular. When spinning glass fibers using a spinning device equipped with the tip nozzle plate with cooling fins described above, at the start of spinning and at the time of cutting the fibers during spinning, especially at the time of cutting the latter fibers, it is formed at the tip of the tip nozzle by cutting. The molten glass beads may crawl up the nozzle wall instead of falling down, filling the gaps between the tip nozzles, overflowing and sticking to the tip nozzles, and especially when the tip nozzles are arranged too closely together. As pointed out above, when such conditions occur, overflow and adhesion almost inevitably occur, and recovery from such conditions is practically impossible under industrially acceptable working conditions and time.

The present invention accomplishes the removal, separation, and formation of a molten glass cone by applying a gas flux to the molten glass that overflows and adheres to the gap between the tip nozzles.

In the inventive method of removing this spilled, sticky molten glass and simultaneously separating and forming a molten glass cone, the applied gas flux is generally a gas that does not adversely affect the molten glass and the metal material of the nozzle plate, i.e. It can consist of a non-reducing gas, such as nitrogen, helium, or air, although air is obviously the most practical.
and preferable.

Therefore, in the following description, a case will be described in which air flux is used as the gas flux. In the present invention, the air flux is caused by overflowing, and while gently pulling the sticky molten glass (hereinafter simply referred to as overflowing glass in some cases) downward, the state of removal and separation of the molten glass is observed with the naked eye. applied while. Here, "slowly pulling and pulling" means that according to the present invention, spilled glass can be easily removed and separated from the adhesive surface by applying an appropriate air flux. It simply means pulling the overflowing glass downwards to the extent that it cannot be grasped completely.
This tension-removal operation can be performed, for example, by grasping the molten glass with tweezers or by adhering a glass rod to the molten glass and pulling it downward while applying an air flux. The air flux should be applied substantially locally to the area of the overflow glass, and conditions in which the air flux impinges on large areas beyond the area of the overflow glass should be avoided.

If the air flux hits a wide area beyond the overflow area, the nozzle plate surface, tip nozzle and molten glass cone in that area will also have a cooling effect, possibly causing not only fiber breakage but also , stop the flow of molten glass from the nozzle and solidify it at the nozzle outlet. In the above, "local" means at most the size of the area surrounded by a line surrounding one tip nozzle and the surrounding tip nozzles that are closest to this central tip nozzle. For example, when the tip nozzles are arranged in a zigzag pattern, the area including the three tip nozzles at the apex and the width of one gap or less between the tip nozzles are also included in the meaning of the term "local". . The extent expressed by the term "local" is obviously relative and can vary depending on the distance between the tip nozzles. In addition, this width is the spread of overflowing sticky molten glass,
Regardless of the size, the spread of the overflow glass is “local”
Of course, there may be cases where the width is larger than that expressed by the term. Since the air flux is applied locally to the overflow glass as described above, it must be thin enough to allow this. Here, the term "thin" clearly corresponds to and follows the definition of the term "local" above. However, from a practical point of view, it is preferable that such a narrow air flux be injected and formed from an air injection nozzle having an inner diameter of about 1 to 671 m. Examples of the injection nozzle and its piping system for forming the air flux are shown in FIGS. 3 and 4.

In FIGS. 3 and 4, the air injection nozzle consists of a thin tube 21, for example a metal tube, preferably with an internal diameter of 1 to 6 mm, at the end opposite the nozzle outlet to facilitate its operation. For this purpose, a flexible tube 22, for example a rubber tube, is connected, via which the injection nozzle 21 is connected to a low-pressure air source 23, such as a compressor or a blower. The air supply pipe system including the air source 23 and connected to the flexible pipe 22 is provided with a regulator valve 24 and a pressure gauge 25, and the injection nozzle 21
The amount and pressure of air can be adjusted. To remove overflowing, sticky molten glass by applying an air flux, and at the same time to separate and form a molten glass cone from the molten glass at each tip nozzle, the air flux is applied so that the molten glass loses its fluidity. However, when the molten glass is grabbed with tweezers and gently pulled downward as described above, sufficient wind pressure is applied to the molten glass to impart viscosity that can sufficiently transmit the pulling force to the molten glass. It must be able to have an impact on The overflowing glass is surrounded by the hot nozzle plate and the tip nozzle, and is covered with hot stagnation gas around the nozzle plate surface and the tip nozzle, and hot molten glass is continuously supplied from the tip nozzle where the fibers are cut. Therefore, it is in a state of extremely low viscosity. Therefore, if the wind pressure of the air flux applied to this is too weak, it will not be possible to cool the molten glass so as to eliminate the stagnant gas and provide sufficient viscosity to transmit the tensile force, and the molten glass will be Glass cannot be removed. On the other hand, if the wind pressure of the air flux is too strong, the molten glass becomes solidified or becomes highly viscous, and in this case, the glass cannot be removed simply by pulling it. Therefore, in order to remove the spilled glass and separate and form the cone, it is necessary to provide the appropriate viscosity as described above, and thus the appropriate viscosity can be achieved by cooling the molten glass with the appropriate air flux. At the same time, the interface between the molten glass and the nozzle plate and tip nozzle is also cooled, reducing the affinity between them and making it easier to remove the molten glass. The cooling ability of the air flux for molten glass depends on its temperature, but for example, when using an air flux around room temperature, the wind pressure applied to the overflowing glass is in the range of tenon 0.1 to 5 class H2O. is appropriate,
Preferably it is in the range of about 0.3-1.5% H2O.

When using the air injection nozzle with an inner diameter of 1 to 67 nt, the distance from the injection nozzle to the overflow glass is within the range of approximately 10 to 300 mm, which is preferable for operation, and the air pressure range is approximately 0.02 mm at the injection nozzle inlet. ~0.3K
f/c! This can be achieved by applying an air flux with a pressure of i. When overflowing or sticking of molten glass occurs, removal of the overflowing glass by the air flux from the air injection nozzle and separation and formation of a molten glass cone are performed as follows.

The overflowing glass is grasped, for example, with tweezers and gently pulled downward, while at the same time an air flux from an injection nozzle set at a predetermined pressure is directed toward the overflowing glass by manually operating the injection nozzle.

At this time, there is no need to change the spinning conditions such as lowering the bushing temperature, and there is no need to remove the cooling fins arranged between the rows of tip nozzles. The air injection nozzle is operated by hand, and the injection nozzle is operated to apply appropriate wind pressure to the overflowing glass, so that this molten glass is moderately removed and separated into cones. This condition can be easily observed with the naked eye. Adjust the position and distance. At this time, the air pressure of the injection nozzle can also be adjusted at the same time according to the removal of molten glass and the state of cone formation. The air flux can be directed onto the overflow glass from below the overflow glass, or from below obliquely, or also from the horizontal direction and, if appropriate, by inserting an injection nozzle between the formed fibers. The spray nozzle can be moved back and forth and left and right within a small range depending on the state of overflow glass removal and separation. In addition, when the overflow glass covers a wide area,
The removal and separation can be carried out starting from the edges and successively affecting the entire extravasation area. The overflowing glass from the molten glass cone is peeled off from the nozzle plate surface and the wall surface of the tip nozzle by the above operation, and is separated for each tip nozzle, so that the molten glass flowing out from each tip nozzle is localized to the bottom surface of the tip of each tip and flows out. As it matures, and thus upon completion of the removal of the overflow glass, it naturally separates and forms as a relatively large cone. This overflow, removal of the sticky molten glass, separation of the cone, and formation operations actually take about 1 minute or less, regardless of the density of the tip nozzle.
And it will be completed within a few minutes at most. Thus, according to the present invention, the molten glass that overflows and sticks between the tip nozzles can be removed in an extremely short time ranging from about one minute to several minutes without changing the spinning conditions including removing the cooling fins.
At the same time, it is possible to separate and form a molten glass cone in each tip nozzle, and this is practically independent of the density of the tip nozzle, as mentioned above, and because the operation is completed in a short time due to the thin flux, other cones can be separated and formed. or can be achieved without substantially affecting the fibers, and therefore also according to the invention the tip nozzles are arranged closely together, exceeding the conventional inter-tip nozzle spacing, e.g. Tip nozzle plates arranged with a distance between the tips of the tips and the outer walls of 0.5 mm can also be used in continuous spinning of glass fibers. Regarding this close-contact tip nozzle, an example of spinning E-glass using a bushing equipped with a tip nozzle plate having the following specifications and in which cooling fins are inserted and arranged every second row between the tip nozzle rows will be shown below. However, it will be apparent to those skilled in the art from the foregoing description that the invention is not limited to these examples. The spinning was carried out at a spinning temperature of approximately 1,230°C, according to specification I.
For spinning rate 700'/min and winding speed 1,220
m/min, and the specification was a spin rate of 700'/min and a winding speed of 1090 m/min.

In these spinning processes, when the fibers are cut, the molten glass beads formed by the cutting often overflow and stick to the gaps between the tip nozzles, and if left unattended, they merge with the surrounding glass cones and the overflow expands. It was observed that

While pulling the overflowing sticky molten glass with tweezers until it has not expanded too much, the pressure obtained from the air injection nozzle with an inner diameter of 4.0 mm is 0.1 Kf for the tip nozzle plate of the former specification 1. /C! i, and for the tip nozzle plate of the latter specification, the pressure obtained from an air injection nozzle with an inner diameter of 2.0 mm. /d air flux, removal of those spillover glasses,
While observing the separation situation with the naked eye, the application state of the air flux was appropriately adjusted and applied by operating the injection nozzle. As a result, in both cases, the overflowing glass was completely removed within 1 minute, and at the same time, a molten glass cone was separated and formed in each tip nozzle, and spinning could be restarted.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a bushing for glass fiber spinning, which has a tip nozzle plate at the bottom and cooling fins are inserted and arranged every two rows between the rows of tip nozzles, and FIG. FIG. 3 is a side sectional view of the bushing shown in FIG. FIG. 4 is a diagram showing a piping system connected to the air injection nozzle of FIG. 3; 1...Four hearth, 3...Butching, 6...Nozzle plate, 8, 8'...
...Terminal, 9...Fireproof castable, 1
4... Molten glass, 15... Chip nozzle, 16... Fiber, 17... Cooling fin, 21... Air injection nozzle, 22・・・・・・
...Flexible tube, 23... Air source, 24.
... Lugilulator valve, 25 ... Pressure gauge.

Claims (1)

[Scope of Claims] 1. In spinning glass fiber using a bushing equipped with a tip nozzle plate at the bottom in which cooling fins are inserted and arranged between rows of tip nozzles, the tip nozzle is inserted at the start of spinning or when cutting the glass fiber. While gently pulling the molten glass that overflowed and stuck to the gap between
characterized by directing a narrow gas flux capable of exerting sufficient wind pressure to impart viscosity to the molten glass that is sufficient to transmit the tensile force, without causing loss of fluidity of the molten glass; A method of separating and forming a molten glass cone from spilling, sticky molten glass. 2. The method according to claim 1, wherein the gas flux is an air flux. 3. The method according to claim 1 or 2, wherein the gas flux has a temperature of about room temperature and exerts a wind pressure of 0.1 to 5 mmH_2O on the overflowing and sticky molten glass. 4. The method according to claim 1, 2 or 3, wherein the gas flux has a pressure of 0.02 to 0.3 Kg/cm^2. 5. The method according to any one of claims 1 to 4, using a tip nozzle plate in which the tip nozzles are closely arranged. 6 The distance between tip outer walls between rows of tip nozzles in which cooling fins are not inserted or between adjacent tip nozzles within a row is 0.
．． 6. The method according to claim 5, wherein the diameter is 3 to 1.5 mm. 7. A method according to any one of claims 1 to 6, characterized in that the narrow gas flux is injected from a freely portable injection nozzle connected to a source of pressurized gas. 8. A method according to claim 7, characterized in that the injection nozzle preferably has a nozzle outlet internal diameter of 1 to 6 mm.