JPH0469573B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is applicable to substances in a viscous state, such as glass,
The present invention relates to a method and apparatus for producing fibers of such materials from plastics, prepared pitches for producing carbon fibers, aluminum precursors, and the like. [Prior Art] The applicant has proposed the RGJ method (rotary gas jet method) as a method for efficiently producing such short fibers (Japanese Patent Publication No. 58-57374, Japanese Patent Application Laid-Open No. 60-86051, etc.). . The RGJ method, if necessary, has a step of blowing a high-temperature, high-pressure gas flow in a spiral shape along a molten glass flow to make the glass fine. More specifically, the viscous material is caused to flow out of an outflow orifice, and a linear high-velocity gas stream (hereinafter referred to as a first ) is blown out, where each of the gas flows has a tangential component along the outer periphery of a cross section that crosses the central axis of the substance, and a component in the tangential direction along the outer periphery of the cross section that crosses the central axis of the substance, and a component in the tangential direction along the outer circumference of the cross section that crosses the central axis of the substance The gas flow has a component that first gradually approaches the central axis of the substance and then gradually moves away from the central axis, so that the gas flow from the outflow start part of the substance is directed toward the central axis of the substance. in a first zone extending to the closest point, causing the substance to rotate about its central axis and to have a substantially conical shape with a cross section that gradually decreases in the direction of its outflow; In a second zone following the zone, the substance is fibrous from the tip of the conical shape and spiraled outward in the outflow direction and radial direction, and then the fibrous substance is blown out from the center. Further stretching is performed by contacting the gas flow that gradually moves away from the axis. The RGJ method blows a high-temperature, high-pressure gas flow spirally along the glass flow flowing out of an orifice to make the glass into fine fibers, so it is a fiberization method with excellent thermal efficiency and can efficiently produce small-diameter fibers. . [Problems to be Solved by the Invention] It has been recognized that the following improvement issues exist in this RGJ method. If the amount of glass flowing out from the orifice is increased in order to increase production, the fiber diameter will increase. Therefore, when trying to obtain glass fibers of 7 μm or less, for example, 3 to 5 μm, there is a limit to the amount of glass flowing out, making it impossible to increase production efficiency. It is an object of the present invention to overcome such problems and to enable efficient production of short fibers with a small diameter at low cost. [Means and effects for solving the problem] As a result of further detailed study on the RGJ method, the present inventors found that as the first high-speed gas flow is ejected, the air surrounding the gas flow Air (atmosphere) moves with the gas flow (this moving air is called a wake) and flows into the area below the orifice from its outer periphery, and this air cools the viscous material, especially the fibers, present in the area below. Therefore, before the fibers are drawn longer,
It has been found that the viscosity of the viscous substance increases to such a level that it no longer stretches even when subjected to a stretching force. The present invention was made based on this knowledge, and in the conventional basic RGJ method in which glass is made into fibers by blowing a first high-speed gas flow in a spiral shape along the molten glass flow flowing out from an orifice,
introducing heated gas into the lower region of the orifice to prevent premature cooling of viscous materials, especially fibers;
This allows the diameter to be reduced. That is, the method for manufacturing fibers of the present invention comprises: flowing a viscous substance through an outflow orifice, and injecting a viscous substance in a straight line from at least three first gas jet nozzles circumferentially spaced around the orifice. 1 of high-velocity gas streams, each of the gas streams having a tangential component along the outer circumference of a cross-section transverse to the central axis of the material;
The outflow flow of the viscous substance has a component that first gradually approaches the central axis of the substance and then gradually moves away from the central axis in the outflow direction of the substance, so that the outflow flow of the viscous substance is It gradually narrows while rotating around its central axis, and then
A method for producing fibers in which the fibers are made into fibers, spun out in a spiral shape, and stretched, including the step of flowing a second gas flow from the periphery toward the lower region of the orifice to heat the lower region. A fiber manufacturing method according to the present invention is characterized in that the fiber manufacturing apparatus of the present invention uses a nozzle for supplying combustion gas such as a gas burner, or air flowing toward the lower region as a means for introducing the heated gas. The system is equipped with a heater. According to the present invention, a viscous substance, particularly fibers, can be maintained at a viscosity that allows drawing for a long time, and fibers with a correspondingly smaller diameter can be obtained. Furthermore, the fiber diameters are uniform, and there is little generation of unfibered material. It should be noted that the improved RGJ method proposed in JP-A-60-86051 and the present invention are fundamentally different in the action of the second gas flow. That is, in JP-A-60-86051, a second high-speed gas flow is injected approximately horizontally toward the fibers stretched by the first high-speed gas ejected from the first gas ejection nozzle; The fibers are blown away in the horizontal direction. In contrast, in the present invention, the second gas stream is combustion gas or heated air supplied as a replacement for at least a portion of the cold wake flowing into the fiberizing region below the orifice from the surroundings. and,
The purpose of this second gas flow is to heat the region, and is not intended to change the flying direction of the fibers drawn by the first high-speed gas flow. , it is not a high-speed gas flow as in JP-A-60-86051. [Example] Hereinafter, the present invention will be described in more detail with reference to the example shown in FIGS. 1 and 2. FIG. 1 is a partial bottom view of a fiberizing apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic partial sectional view taken along the line - in FIG. 1. In FIGS. 1 and 2, reference numeral 1 denotes a fiberizing device (platinum pot) that holds viscous molten glass 2, and a plurality of molten glass outflow orifices 3 are provided at predetermined intervals at the bottom. M is the opening of this orifice 3, and the molten glass 2 enters the cone 4.
It flows out while forming. a ₁ , b ₁ , a′ ₁ , b′ ₁ are arranged almost symmetrically around the molten glass outflow orifice 3 (opening M), and are connected to a manifold 5, which is inserted through the bottom wall of the platinum pot 1.
The openings of the first gas ejection nozzles 6, 6' communicating with the gas nozzles 5' are shown. These first gas jetting nozzles 6, 6' have their spouting ports that emit a component in a tangential direction along the outer periphery of a cross section that crosses the central axis of the molten glass 2, which is a viscous material flowing out from the orifice 3, and glass 2
The outflow flow is disposed so as to be oriented in a direction having components that first gradually approach the central axis of the outflow flow and then gradually move away from the central axis of the outflow flow. Although four first gas ejection nozzles are shown in FIG. 1, the number is not limited.
Moreover, in the glass fiber forming apparatus of the present invention, the first
The gas ejection nozzles are preferably arranged approximately symmetrically around the molten glass outflow orifice 3. Furthermore, a plurality of auxiliary gas ejection nozzles may be provided outside the first gas ejection nozzle, the center axis of which is the point where the center axis of the first gas ejection nozzle is closest to the center axis of the outflow orifice 3. , that is, the molten glass has a second convergence point further below the first convergence point A and substantially or completely converges on the central axis of the molten glass outflow orifice 3, or the molten glass It may be parallel to the central axis of the outlet orifice. In Figures 1 and 2, 8 and 8' are orifices 3
A second nozzle for causing a second gas flow for heating the region to flow into the lower region of the nozzle, and is disposed opposite to the orifice 3. In this embodiment, the nozzles 8 and 8' are gas burner nozzles, into which a fuel gas such as butane and a gas containing oxygen such as air are introduced, and the combustion gas is passed through the second gas flow 9, 9' is installed in a substantially horizontal position so as to flow toward the center axis of the orifice. In addition, a long pipe is arranged on both sides of the bottom of the platinum pot 1 so as to extend in the longitudinal direction, and an opening is provided as a combustion port at a location corresponding to the orifice 3 of this long pipe to form a slit burner. 2nd from the opening
It may be configured to generate a gas flow of . Thus, the openings a ₁ , a′ 1 , a′ ₁ , of the first gas jet nozzle,
The glass flow receives a rotational force from the first high-speed gas flow (gas flow) emitted from b ₁ and b' ₁ , and the gas from the first gas jet nozzles 4 and 4' reaches the center axis of the orifice 3. When it passes the convergence point A, which is the point closest to the glass, it is released, and its own centrifugal force causes it to fly out in the radial direction perpendicular to the central axis of the glass outflow orifice 3, becoming fibers. In the device of this embodiment, the combustion gases 9, 9' supplied from the second nozzles 8, 8' heat the fiberization area below the orifice 3, so the cooling rate of the produced fibers is small and the fibers are long. The material is maintained in a temperature range that provides a viscosity that allows stretching over a period of time. As a result, fibers with a small diameter can be obtained. In addition, when the above-mentioned auxiliary gas ejection nozzle is provided, the gas flow blown out from the auxiliary gas ejection nozzle helps to efficiently fiberize the glass flow, so that thinner fibers can be obtained. The amount of thermal energy Kca/hr of the gas streams 9, 9' from the second nozzles 8, 8' is equal to that of the first high-speed gas stream.
It is preferably about 20 to 150%, especially about 30 to 100%. Also, the gas flow 9, from the second nozzle 8, 8'
The temperature of 9' is 500℃ when making glass fiber.
℃ or higher, preferably 800℃ or higher. However, although it varies depending on the glass composition, if the temperature is too high, the fibers will re-melt and their surface tension will prevail, resulting in a spherical shape. Other preferable conditions for the glass fiber forming apparatus of the present invention shown in FIGS. 1 and 2 are as follows. Orifice diameter and nozzle diameter and length Diameter of the molten glass outflow orifice (D ₀ in Figure 2): 0.4 to 2.5 mm, preferably 0.5 to 2.0 mm Diameter of the first gas injection nozzle (D ₁ in Figure 2) ): 0.2 to 1.5 mm, preferably 0.5 to 0.8 mm Length of the first gas jet nozzle (G ₁ in Figure 2): 1 to 7.5 mm, preferably 1.5 to 4.0 mm First gas jet nozzle in cross section Positional relationship: Distance between the central axes on the opening plane (S ₁ in Figure 2): 1 to 5 mm, preferably 1.2 to 4 mm The virtual plane perpendicular to the central axis of the molten glass outflow orifice and the center of the first gas jet nozzle Angle with the axis (α in Figure 2): 20 to 70°, preferably 35 to 55° Vertical distance between the aperture surface and the first convergence point A (L ₁ in Figure 2): 0.5 to 3 mm, preferably 1 to 2 mm Positional relationship of the second nozzle in cross section It is preferable that the space within 100 mm, preferably within 60 mm below the bottom of the first gas jet nozzle is heated by the second gas nozzle. Positional relationship of gas jetting nozzles in a plane Relationship between two first gas jetting nozzles located opposite to the molten glass outflow orifice, that is, in a virtual plane that passes through the first convergence point A and is perpendicular to the central axis of the molten glass outflow orifice. Distance between the central axes of two gas ejection nozzles (S _G in Figure 1): 0.5 to 2 mm, preferably 0.7 to 1.5 mm Distance between the central axes of adjacent molten glass outflow orifices (P in Figure 1): 1.0~20mm, preferably
1.5 to 7 mm FIG. 3 is a longitudinal cross-sectional view of a device according to a different embodiment of the present invention. In this embodiment, the first,
This is different from the embodiment shown in FIG. In this embodiment, the air flowing into the lower region of the orifice with the first high-speed gas flow is heated by passing between the heaters 10, so that the temperature decrease due to the inflow of cold air in the lower region is prevented. suppressed. Then, the molten glass and fibers are kept in a temperature range that has a viscosity that allows them to be drawn for a longer period of time, and thinner fibers can be obtained. The electric heater 10 may be annular as shown in FIG. 4 and may be provided to surround the orifice 3, or may be provided so as to extend along both sides of the pot 1 as shown in FIG. Also good. FIG. 6 is a sectional view illustrating still another embodiment of the present invention. In this embodiment, the second nozzle 8,
In order to prevent the atmosphere from flowing into the lower area of the orifice 3 from the side portion of the orifice 8', a partition plate 11 is provided to isolate the lower area from the outer periphery thereof. This partition plate may have a cylindrical shape so as to surround the lower area of the orifice 3, as in the annular heater shown in FIG. It may be provided. Alternatively, it may be provided only near the nozzles 8, 8'. FIG. 7 is a bottom view of essential parts showing an embodiment in which an electric heater and a partition plate are used together. In the embodiment shown in FIG.
A partition plate 11 is arranged between them. If a partition plate is provided as shown in FIGS. 6 and 7, the inflow of cold air into the region below the orifice 3 will be reduced accordingly, making it possible to obtain even thinner fibers. The second nozzles 8, 8', the heater 10, the partition plate 11, etc. are arranged as symmetrically as possible across the central axis of the orifice 3, so that the flow of gas flowing into the region below the orifice is equalized. It is preferable to configure it as follows. Manufacturing examples and comparative examples will be described below. Example 1 Using the example apparatus shown in Figs. 1 and 2, SiO ₂ 40
%, A ₂ O ₃ 13%, CaO 22%, Na ₂ O + K ₂ O 18%,
40Kg/Hr of molten glass with a composition of 4% B ₂ O ₃
and flowing out at a rate of 90 Kg/Hr, while maintaining the internal pressure of the manifolds 5, 5' communicating with the first gas jet nozzles 6, 6' at 3 Kg/cm ² and the gas temperature at 1200°C.
The first high-speed gas flow is ejected, and the slit width S ₃
Butane combustion gas was generated from a second nozzle having a diameter of 15 mm. Table 1 shows the average fiber diameters obtained when the amount of butane used was 1 Kg/Hr and 2 Kg/Hr. Comparative Example 1 Glass fibers were produced in the same manner as in Example 1, except that butane was not combusted through the second nozzle. Table 1 shows the average diameter of the obtained fibers. From Table 1, according to the example, compared to the comparative example, 15
It is observed that fibers with a smaller diameter by ~30% can be obtained.

[Table] [Effects] According to the present invention, combustion gas, heated air, etc. flow into the fiberization region below the orifice, so the temperature of the region is maintained and the fibers are stretched by the first high-speed gas flow. The fibers are maintained at a viscosity that allows them to be drawn for a long time, and small fibers with uniform fiber diameters can be obtained.
Furthermore, the flow of the first high-speed gas flow is not disturbed, and high-quality fibers containing almost no unfiberized material can be produced. Further, by adjusting the temperature and/or flow rate of the second gas flow, the degree of stretching can be adjusted, and the fiber diameter can be easily adjusted, and the range of adjustment can be widened. When performing fiberization of molten glass according to the present invention, thin fibers can be easily obtained compared to the case where a glass fiberization apparatus having only the first gas jet nozzle is used. In addition, compared to the flame stretching method, the thermal energy used for heating stretching is small.
Very fine fibers can be obtained at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic partial bottom view of an embodiment of the fiberizing apparatus of the present invention, and FIG. 2 is a schematic partial cross-sectional view taken along the line - in FIG. 1. FIG. 3 is a sectional view illustrating another embodiment of the present invention, and FIGS.
The figure is a partial bottom view, and FIGS. 6 and 7 are a sectional view and a partial bottom view, respectively, illustrating further different embodiments. 2... Molten glass, 3... Outflow orifice,
6, 6'...first gas jet nozzle, 8, 8'...
Second nozzle, 9, 9'...second gas flow, 10
...Electric heater, 11...Diameter.

Claims (1)

[Scope of Claims] 1. A viscous material obtained by heating a heat-softening material is caused to flow out from an outflow orifice, and at least three at least three viscous materials are arranged around the orifice at intervals in the circumferential direction.
A first heated high-velocity gas flow is blown out in a straight line from a first gas ejection nozzle of the book, wherein each of the gas flows has a tangential component along the outer circumference of a cross section transverse to the central axis of the substance. , and a component that first gradually approaches the central axis of the substance and then gradually moves away from the central axis in the outflow direction of the substance, whereby the outflow flow of the viscous substance gradually narrows while rotating around the central axis, and then
A method for producing fibers in which the fibers are made into fibers, spun out in a spiral shape, and stretched, including the step of flowing a second heated gas from the periphery toward the lower region of the orifice to heat the lower region. Characteristic fiber manufacturing method. 2. The method of claim 1, wherein the second gas stream is combustion gas or heated air. 3. An outflow orifice for outflowing a viscous substance, and at least three first gas ejection nozzles circumferentially spaced around the outflow orifice, the first gas ejection nozzles comprising:
The jet ports gradually approach the central axis of the substance in the direction of the outflow direction of the substance, and then the central axis of the substance. A second nozzle for supplying combustion gas toward a region below the orifice is provided substantially horizontally in a fiber manufacturing apparatus that is disposed so as to be oriented in a direction in which a component gradually moves away from the orifice. A fiber manufacturing device characterized by: 4. The device according to claim 3, wherein a plurality of the second nozzles are arranged. 5. The device according to claim 3 or 4, further comprising a partition plate for separating at least a portion of the lower region of the orifice from its outer periphery. 6 comprising an outflow orifice for outflowing a viscous substance and at least three first gas ejection nozzles circumferentially spaced around the outflow orifice, the first gas ejection nozzles comprising:
The jet ports gradually approach the central axis of the substance in the direction of the outflow direction of the substance, and then the central axis of the substance. In the fiber manufacturing apparatus, which is disposed so as to be oriented in a direction in which a component gradually moves away from the orifice, a heater is provided for heating air flowing from around the orifice toward a lower region of the orifice. Fiber manufacturing equipment featuring: 7. The device according to claim 6, further comprising a diaphragm for separating a portion of the lower region of the orifice from its outer periphery.