JP2009263211A - Deformed cross-section glass fiber and its producing method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the precision molding of a deformed cross-section glass fiber by reducing the variation of the viscosity of molten glass at forming as quickly as possible by rationalizing the shape of a nozzle. <P>SOLUTION: In a method for producing the deformed cross-section glass fiber whose cross-sectional surface vertical to a drawing out direction has a flat shape because of drawing out the molten glass G from a nozzle hole 11 in the nozzle 10 where the flat nozzle hole 11 having a long axis T and a short axis perpendicular to the long axis T is formed at the bottom of a molten glass storing vessel stored with the molten glass G, the nozzle 10 having a projected part 10a projected along the drawing out direction from the half or lower of the peripheral part of the nozzle hole 11 whose boundary is the long axis T of the nozzle hole 11 at its edge part is used. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a glass fiber, and more particularly to a modified cross-section glass fiber in which a cross section perpendicular to a drawing direction of molten glass forms a flat shape.

  A modified cross-section glass fiber having a flat shape such as an oval or elliptical cross section can be used in a wide range of fields because it can provide a high reinforcing effect when mixed with a resin to form a composite.

  Such a modified cross-section glass fiber is produced by cooling while pulling out the molten glass from a nozzle provided at the bottom of the molten glass storage tank in which the molten glass is stored. And, since the shape of the nozzle hole used at this time forms the basis of the shape of the cross section of the glass fiber to be manufactured, a nozzle having a flat nozzle hole is used in the manufacture of the deformed cross section glass fiber. Often done.

  However, compared to glass fibers having a circular cross section, it is generally difficult to produce irregular cross-section glass fibers due to the uniqueness of the shape. In other words, even if a nozzle having a flat nozzle hole is used, if the viscosity of the molten glass drawn from the nozzle is inappropriate, the molten glass flowing down from the nozzle hole is rounded by the surface tension just below the nozzle. It is easy to take, and the desired irregular cross-section glass fiber cannot be produced.

  Therefore, in Patent Document 1, a notch is provided in a part of the tip of the nozzle, and the molten glass is cooled through the notch to adjust the viscosity of the molten glass. In the same document, the notch is provided in a region less than a half circumference of the nozzle hole with the major axis of the flat nozzle hole as a boundary. In other words, at the tip of the nozzle, the peripheral edge of the nozzle hole excluding the notch is a protrusion that protrudes relative to the formation area of the notch, and this protrusion is the nozzle hole. The nozzle hole is provided in a region exceeding a half circumference of the nozzle hole with the major axis as a boundary.

JP 2003-048742 A

  By the way, in the nozzle disclosed in Patent Document 1, since the protruding portions are formed at the peripheral edge of the nozzle hole exceeding the half circumference with the long axis of the nozzle hole as the boundary as described above, both ends in the long axis direction of the nozzle hole are formed. In the portion, both surfaces of the molten glass are sandwiched between the protruding portions of the nozzle. On the other hand, since the surface on one side of the molten glass faces the notch portion of the nozzle at the central portion in the major axis direction of the nozzle hole, only the surface on the other side of the molten glass is in contact with the protruding portion. It becomes. Therefore, the both sides of the molten glass are difficult to be cooled by the protruding portions at both ends in the long axis direction of the nozzle hole, whereas the one side of the molten glass is easily cooled through the notch at the central portion in the long axis direction of the nozzle hole. That is, the narrow area | region which faces the notch part is partially cooled among the one surfaces of molten glass, and a viscosity tends to fall locally. And when the part in which viscosity differs partially in molten glass is formed in this way, it will become the obstruction at the time of shaping | molding, and the problem that it is difficult to shape | mold a precise shape will arise.

  In view of the above circumstances, the present invention aims to optimize the shape of the nozzle to reduce the variation in the viscosity of the molten glass at the time of molding as much as possible, and to realize the precision molding of the modified cross-section glass fiber. Technical issue.

  In order to solve the above problems, the glass fiber manufacturing method according to the present invention has a flat shape having a major axis and a minor axis perpendicular to the major axis at the bottom of the molten glass reservoir in which molten glass is stored. A modified cross-section glass fiber is produced in which a cross-section perpendicular to the drawing direction is formed into a flat shape by providing a nozzle in which a nozzle hole is formed and drawing molten glass from the nozzle hole of the nozzle In the method, the nozzle having a protruding portion that protrudes along the pull-out direction from a peripheral portion of the nozzle hole that is not more than a half circumference with the long axis of the nozzle hole as a boundary is used as the nozzle. Characterized.

  According to the above method, since the nozzle having the protruding portion at the peripheral edge of the nozzle hole half or less is used, both surfaces of the molten glass are sandwiched between the protruding portions at both ends in the long axis direction of the nozzle hole. It will not be in the state. That is, at least the entire surface of the molten glass is a free surface that does not face the protruding portion, so that it is difficult to form a place that is easily cooled locally or a place that is difficult to be cooled, and quickly cools the entire molten glass. be able to. Therefore, it is possible to reliably suppress a situation in which the molten glass is deformed to be round due to the surface tension immediately below the nozzle while suppressing variation in the viscosity of the molten glass. Therefore, if glass fiber is manufactured using the nozzle which makes the said shape, it will become possible to precisely shape the irregular cross-section glass fiber that satisfies the desired shape.

  In said method, it is preferable that the head pressure of the said nozzle at the time of pulling out glass fiber from the said nozzle exists in the range of 2 kPa or more and 500 kPa or less.

  That is, when the head pressure of the nozzle is less than 2 kPa, the outflow amount of the molten glass is reduced, so that the molten glass is easily cooled early. Therefore, there is a possibility that the molten glass is solidified before being sufficiently stretched and is cut in the middle. It is also possible to prevent the above solidification phenomenon at the nozzle by raising the temperature of the molten glass, but in this case, the molten glass tends to be rounded by the surface tension and has a highly flat cross-section glass fiber. May not be obtained. On the other hand, if the head pressure of the nozzle exceeds 500 kPa, a considerable pressure resistance is required for the molten glass storage tank. For example, if the wall surface of the storage tank is made considerably thick, it cannot be endured. As a result, the production of the storage tank is very expensive, and the production cost increases and is not practical. Therefore, the head pressure of the nozzle is preferably within the above numerical range where such a problem does not occur, and more preferably within the range of 2.2 kPa to 100 kPa. Further, from the viewpoint of ensuring further shape stability of the glass fiber, the nozzle head pressure is preferably in the range of 2.3 kPa to 65 kPa, and preferably in the range of 2.3 kPa to 29 kPa. It is more preferable.

  In the above method, the head pressure of the nozzle may be adjusted by pressurizing the liquid surface of the molten glass stored in the molten glass storage tank.

  In this way, fine adjustment of the nozzle head pressure is facilitated. As a result, the variation in the flow rate of the molten glass drawn from the nozzle is minimized and stabilized. Therefore, fluctuations in the size and outer shape of the cooled and solidified glass fiber can be suppressed, and stable quality can be more reliably maintained.

  In addition, as a method of pressurizing the surface of the molten glass staying in the molten glass storage tank, a gas that does not adversely affect the molten glass (for example, air, nitrogen, carbon dioxide, helium, argon, neon, etc.) is melted. It is preferable to pressurize the glass surface.

  In the above method, the head pressure of the nozzle may be adjusted by controlling the depth of the molten glass stored in the molten glass storage tank.

  In this way, fine adjustment of the nozzle head pressure is facilitated. As a result, the variation in the flow rate of the molten glass drawn from the nozzle is minimized and stabilized. Moreover, it becomes possible to adjust the flow rate of the molten glass discharged from the nozzle at the same time by monitoring the depth of the molten glass.

  In addition, in the manufacturing method of the irregular cross-section glass fiber of this invention, you may shape a glass fiber directly from molten glass, or may manufacture indirectly. In the latter case of indirect production, first, a glass in the form of marble is once formed from molten glass, and after cooling to room temperature and solidifying the glass marble, the glass marble is heated again. You may make it manufacture a deformed cross-section glass fiber by pulling out the molten glass from a nozzle, for example, adjusting the molten glass depth as mentioned above, or pressurizing the surface of a molten glass with pressurized gas.

  The modified cross-section glass fiber according to the present invention, which was created to solve the above problems, is a modified cross-section glass fiber manufactured by a manufacturing method having the above-described configuration as appropriate, and the aspect ratio of the cross section is 1. It is characterized by being in the range of 5 or more and 10.0 or less.

  That is, if the flatness ratio is less than 1.5, the isotropic property obtained by the flattening is hindered and sufficient performance may not be exhibited. On the other hand, if the flatness ratio exceeds 10.0, defects such as scratches and chippings are likely to occur at both ends in the major axis direction of the cross section of the glass fiber, and therefore there is a possibility that high mechanical performance cannot be exhibited even if they are combined. Therefore, the modified cross-section glass fiber according to the present invention that can be precisely formed by the above production method is preferably molded so that the flatness ratio is within the above numerical range, and is within the range of 1.6 or more and 9.8 or less. It is more preferable that it is in the range of 1.8 or more and 9.6 or less.

  Said structure WHEREIN: It is preferable that the 1 or more convex part or recessed part is formed in the outline of the said cross section.

  In this way, the structure having high isotropy not only in the mechanical strength in the direction perpendicular to the major axis direction in the cross section of the glass fiber but also in the mechanical strength parallel to the drawing direction (spinning direction). Can be realized.

  In addition, the said convex part or a recessed part is parallel to the shortest diameter direction, when the length with which the distance between the straight lines becomes the shortest when the cross section of the glass fiber is sandwiched between two parallel straight lines is the shortest diameter direction. The height or depth is preferably in the range of 3% to 50% of the shortest diameter. That is, when the size of the convex portion or the concave portion is less than 3% of the shortest diameter of the cross section, the irregular shaped glass fiber having the convex portion or the concave portion is combined with a resin material, and then the convex portion or the concave portion. And there is a possibility that the engagement with the resin material becomes weak. On the other hand, if the size of the convex portion or the concave portion exceeds 50% of the shortest diameter of the cross section, the variation in the shape of the glass fiber may increase. Therefore, the size of the convex portion or the concave portion is preferably within the above numerical range in which such a problem does not occur, more preferably within the range of 4% or more and 45% or less, and more preferably 5% or more and 40%. More preferably within the following range.

  In addition, in the cross section of glass fiber, the above-mentioned convex part or recessed part is formed by adjusting appropriately the temperature and the outflow speed of the molten glass which flow out from a nozzle hole, for example.

  Specifically, for example, when forming the convex portion, the temperature of the molten glass is set to a high temperature state, and the molten glass that has flowed out of the nozzle holes is more likely to be softened and deformed before being cooled and solidified. Since the nozzle has a protruding portion that protrudes in the pull-out direction from the peripheral portion of the nozzle hole that is less than or equal to a half circumference in the longitudinal direction, the molten glass that has flowed out of the wall portion of the non-projecting portion on the side facing the protruding portion is The molten glass that has flowed out of the protruding portion is opened to the outside prior to the molten glass and tends to be rounded by the surface tension, and since the viscosity is low, the molten glass flows out of the protruding portion side to the molten glass side. Will form.

  For example, when forming the recess, in addition to increasing the temperature of the molten glass, the head pressure is increased to increase the outflow amount of the molten glass, and the drawing speed of the glass fiber is further increased. Then, the molten glass that has flowed out from the wall of the non-projecting part of the nozzle goes around to the projecting part side, and the molten glass on the projecting part side whose cooling rate has been lowered by the wraparound is pulled out at a high speed to form a recess. .

  In the above configuration, the equivalent circle diameter is preferably in the range of 3 μm to 40 μm.

  If it does in this way, it will become especially useful as a glass fiber which has the stable precision dimension used for the use which requires the high stability of a dimension after compounding.

  In this case, it is further preferable that the dimension in the major axis direction of the cross section of the glass fiber is in the range of 4 μm to 40 μm. In this way, not only the performance after molding can be improved, but also molding with stable dimensional quality maintained by adjusting the head pressure of the nozzle, spinning efficiency is high, and the rate of yarn breakage during production Can be suppressed.

  The glass fiber manufacturing apparatus according to the present invention, which was created to solve the above problems, has a flat shape having a major axis and a minor axis perpendicular to the major axis at the bottom of the molten glass storage tank in which the molten glass is stored. A modified cross-section glass fiber is produced in which a cross-section perpendicular to the drawing direction is formed into a flat shape by providing a nozzle in which a nozzle hole is formed and drawing molten glass from the nozzle hole of the nozzle The apparatus is characterized in that a protruding portion that protrudes along the pull-out direction from a peripheral portion of the nozzle hole that is not more than half a circumference of the nozzle hole is defined as a boundary at the tip of the nozzle.

  According to such a structure, the effect obtained from the basic structure described by the said method can be enjoyed similarly.

  According to the present invention as described above, the range of the protruding portion formed at the tip of the nozzle becomes appropriate, the variation in the viscosity of the molten glass at the time of molding is reduced as much as possible, and the precision molding of the irregular shaped glass fiber is performed. Can be realized.

It is a longitudinal cross-sectional view which shows typically the manufacturing apparatus of the irregular cross-section glass fiber which concerns on Example 1 of this invention. It is an enlarged view of the nozzle of FIG. 1, (A) is a longitudinal cross-sectional view, (B) is XX sectional drawing of (A). It is a longitudinal cross-sectional view which shows the arrangement | positioning state of the cooling pipe around the nozzle of FIG. It is a cross-sectional view which shows typically the deformed cross-section glass fiber manufactured. It is a longitudinal cross-sectional view which shows typically the manufacturing apparatus of the irregular cross-section glass fiber which concerns on Example 2 of this invention. It is a cross-sectional view which shows typically the irregular cross-section glass fiber which concerns on Example 3 of this invention. It is a cross-sectional view which shows typically the irregular cross-section glass fiber which concerns on Example 4 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a longitudinal cross-sectional view schematically showing a modified cross-section glass fiber manufacturing apparatus according to Embodiment 1 of the present invention. In the figure, 10 is a platinum alloy nozzle, 11 is a nozzle hole, 20 is a platinum alloy container as a molten glass reservoir, 21 is a molten glass upper space in the platinum alloy container, 22 is a pressurized gas introduction tube, 30 Is a platinum alloy pipe, 40 is a feeder, 50 is a bushing, 60 is a glass fiber winding device, 70 is a water-cooled tube, A is a pressurized gas introduction direction, and F is a modified cross-section glass fiber.

  This manufacturing apparatus obtains a modified cross-section glass fiber F by heating a plurality of glass raw materials to obtain a uniform molten glass and then spinning the glass fiber directly from the molten glass G in a continuous process. In this case, it is possible to provide a plurality of feeders 40 in a glass melting furnace (not shown), and FIG.

  The molten glass G of E glass material heated in a glass melting furnace (not shown) and homogenized by a stirring operation or the like flows into the feeder 40. The molten glass G that has flowed into the feeder 40 flows through the platinum alloy heat-resistant pipe 30 disposed on the downstream side of the feeder 40, flows into the platinum alloy container 20, and is stored. The bottom of the platinum alloy container 20 is constituted by a rectangular bushing 50 made of platinum alloy. In the bushing 50, a plurality (400 in the present embodiment) of platinum alloy nozzles 10 are arranged in a state where the nozzle holes 11 are aligned at equal intervals in the vertical direction.

  As shown in FIGS. 2A and 2B, the platinum alloy nozzle 10 has a flat nozzle hole 11, and the tip of the nozzle 10 has a half circumference with the major axis T of the nozzle hole 11 as a boundary. It has the protrusion part 10a which protruded in the drawing-out direction (downward) of the molten glass G from the following periphery.

  Specifically, in this embodiment, the nozzle 10 has a shape having a protruding portion 10a in which the entire peripheral edge of the nozzle hole 11 having the major axis T as a boundary protrudes downward. That is, the nozzle 10 has an asymmetric shape with respect to a plane H including the major axis T of the nozzle hole 11 and parallel to the drawing direction of the molten glass G. And since this protrusion part 10a is formed in the part corresponded to just the half circumference of the flat nozzle hole 11, the part equivalent to the remaining half periphery becomes a non-projection part, and a notch part is provided in the front end side of the non-projection part. 10b is formed. The shape of the nozzle hole 11 has an oval appearance as shown in FIG. That is, the shape of the outline of the nozzle hole 11 has a straight part 11a parallel to the long axis T of the nozzle hole 11 in the cross section of the nozzle 10 and a curved part 11b connected to the end of the straight part 11a. It has become. Further, in this case, the nozzle hole 11 has a ratio of the major axis dimension to the minor axis dimension (major axis dimension / minor axis dimension) in FIG. Is preferred.

  As shown in FIG. 1, a pressurized gas introduction pipe 22 is connected to the ceiling of the platinum alloy container 20, and the platinum alloy container 20 stores the pressurized gas through the pressurized gas introduction pipe 22. A high-pressure gas is introduced into the upper space 21 of the molten glass G. Thereby, the surface of the molten glass G stored in the platinum alloy container 20 is evenly pressurized, and the head pressure of the nozzle 10 is adjusted by the magnitude of the applied pressure.

  Here, the high-pressure gas introduced from the pressurized gas introduction tube 22 is not particularly limited as long as it does not adversely affect the molten glass G. For example, air, nitrogen, carbon dioxide, helium, argon, Neon etc. can be used.

  The internal pressure of the platinum alloy container 20 is measured by a pressure gauge (not shown) such as a manometer, and the pressurizing condition is adjusted so as to be an appropriate value based on the measured value. The pressurization condition is adjusted by adjusting the pressure of the introduced high-pressure gas, and the pressure of the high-pressure gas is adjusted based on the measured value of the internal pressure of the platinum alloy container 20. And by operating the release valve. Then, by adjusting the pressure of the high-pressure gas, the nozzle head pressure at the outlet of the nozzle hole 11 of the nozzle 10 is adjusted to be in the range of 2 kPa to 500 kPa.

  In addition, when pressurizing the liquid level of the molten glass G as described above, if the measured value of the pressure is stored cumulatively, the pressure is adjusted to an appropriate value by correcting the deviation from the past measured value. be able to. Moreover, the control system of the internal pressure adjusting device in the platinum alloy container 20 is not only an on / off control system using an on-off valve, but also continuously controlling the opening cross-sectional area of the inlet from the pressurized gas introduction pipe 22 to be introduced. A method of adjusting by continuously controlling the opening cross-sectional area of the outlet for exhausting gas other than the inlet provided in the platinum alloy container 20, or a combination thereof Any method may be used.

  The first reason for adjusting the head pressure of the nozzle 10 within the range of 2 kPa or more and 500 kPa or less is that the glass fiber F can be formed without any problem as long as it is within the numerical range. Because. The second reason is that if the above numerical value range is deviated, the following problems may occur in the formation of the glass fiber F. That is, when the case where the head pressure was set to 1.9 kPa was examined, yarn breakage occurred frequently at the head pressure, and the reduction in the yield rate and the deterioration in work efficiency became conspicuous. On the other hand, when the case where the head pressure was set to 520 kPa was examined, the bushing 50 started to deform immediately at the head pressure, and as a result, the molten glass G was removed from a part of the welded portion between the bushing 50 and the platinum alloy container 20. A leak occurred. Therefore, from such a result, in order to form the glass fiber F without any problem, it has been found that the head pressure of the nozzle 10 is preferably set to the above numerical range.

  When the molten glass G is drawn downward from the nozzle hole 11 of the nozzle 10 under the above head pressure conditions, the molten glass G is precisely formed due to the shape of the nozzle 10. That is, as shown in FIG. 2, the nozzle 10 has protrusions 10 a at the peripheral edge of the half circumference of the nozzle hole 11 having the major axis T as a boundary. In addition, both surfaces of the molten glass G are not sandwiched between the protrusions 10a. That is, since the whole surface of the molten glass G becomes a free surface facing the notch 10b, it is difficult to form a place that is easily cooled locally or a place that is difficult to be cooled, and faces the notch 10b of the molten glass G. The entire portion corresponding to the half circumference of the nozzle hole 11 can be quickly cooled under substantially the same conditions. For this reason, it is possible to prevent the molten glass G from being unduly rounded by the surface tension immediately below the nozzle 10 while suppressing the variation in the viscosity of the molten glass G. Therefore, if it manufactures using the nozzle 10 which makes the said shape, it will become possible to shape | mold precisely the irregular cross-section glass fiber F which satisfies the expected shape.

  Further, in this embodiment, as shown in FIG. 1, a cooling pipe 70 that cools the molten glass G drawn from the nozzle 10 is disposed in the vicinity of the periphery below the nozzle 10. By this cooling pipe 70, the molten glass G is rapidly cooled from a high temperature of 1000 ° C. or higher. Therefore, the molten glass G drawn out from the nozzle hole 11 has the viscosity of the molten glass G rapidly increased, so that the surface tension hardly acts and the tendency of the cross-sectional shape to be rounded is suppressed. As a result, the molten glass G solidifies as it is without greatly changing from the cross-sectional shape when drawn out from the oval nozzle hole 11 and becomes a modified cross-section glass fiber F. Then, the manufactured irregular cross-section glass fiber F is wound as a fiber bundle on a bobbin of a winding device 60 to which a sizing agent is applied and disposed below the nozzle 10.

  In this embodiment, as shown in FIG. 3, the cooling pipe 70 is disposed in a positional relationship so as to sandwich the nozzle 10 and at a constant distance from the bushing 50 so as to be parallel to the bushing 50. Has been. Further, the cooling water W is circulated inside the cooling pipe 70 so that a predetermined cooling effect is always obtained.

  As shown in FIG. 4, the glass fiber F continuously produced by using the manufacturing apparatus as described above has a major axis dimension a and a minor axis dimension in a cross section perpendicular to the drawing (spinning) direction. Where b is the cross-sectional aspect ratio (a / b), that is, the flatness ratio is in the range of 1.5 to 10.0. And if it is such glass fiber F, by forming a composite material by using together with various resin materials, distortion etc. will not arise easily in the obtained composite material, and high shape maintenance nature is realized. it can.

  In addition, from the viewpoint of enjoying such operational effects, the flatness ratio of the modified cross-section glass fiber F is preferably in the range of 2.1 to 9.0, and in the range of 2.4 to 8.0. Is more preferably within the range of 2.7 to 7.0, and most preferably within the range of 3.1 to 6.0.

  Moreover, the glass fiber F manufactured in this way can make the equivalent circular diameter of the outline of a cross section into the range of 5-30 micrometers, for example. Here, the equivalent circle diameter represents the diameter of a circle having an area equal to the area of the cross section of the glass fiber. For calculation of the equivalent circle diameter, an image of the cross section of the glass fiber is taken and analyzed. Using a method, the diameter of a circle corresponding to a perfect circle with the same area may be derived. If the range is not less than 5 and not more than 30 μm, it may be difficult to adjust the manufacturing conditions so as to obtain a desired irregular cross-sectional shape.

  Furthermore, the glass fiber F manufactured in this way has a value obtained by dividing the square of the diameter value of the cross section perpendicular to the drawing direction by the tex number of the glass fiber bundle composed of the plurality of glass fibers F and 10 or less. can do.

  The value obtained by dividing the square of the diameter value of the cross section perpendicular to the drawing direction of the glass fiber F by the tex number of the glass fiber bundle composed of the plurality of glass fibers F is 10 or less. The value obtained by dividing the square of the equivalent circle diameter in μm of the surface by the number of grams per 1000 m of fiber bundles composed of a plurality of glass fibers F is greater than 0 and 10 or less. Yes. Here, for the value obtained by dividing the square of the diameter value of the cross section of the glass fiber F by the tex number of the glass fiber bundle composed of the plurality of glass fibers F, the tex number is an anonymous number, so this value is also An anonymous number.

  When the value obtained by dividing the square of the diameter value of the cross section of the glass fiber F by the number of texes of the glass fiber bundle composed of the plurality of glass fibers F is larger than 10, the number of the glass fibers F constituting the fiber bundle is In applications where glass fiber bundles, such as glass fiber reinforced resin, are used too much, glass fiber bundles are subjected to various loads such as unwinding, twisting, vibration, etc. There is a possibility that a phenomenon that hinders the occurrence of the problem. From such a viewpoint, the value obtained by dividing the square of the diameter value of the cross section of the glass fiber F by the tex number of the glass fiber bundle is more preferably 5 or less, more preferably 2 or less, more preferably 1 or less, and most preferably. Is 0.5 or less.

  Specifically, when the head pressure of the nozzle 10 was set to 25 kPa, the manufactured glass fiber F had an equivalent circle diameter of 12 μm and a flatness ratio of 4.5. Moreover, the value which remove | divided the square of the diameter value of the cross section of this glass fiber F by the tex number of the glass fiber bundle comprised from several glass fiber F was 0.61.

  Moreover, it has confirmed that what has the cross-sectional shape extended in the longitudinal direction from which an equivalent circle diameter is 16 micrometers and an aspect ratio becomes 3.8 by changing the winding speed | rate etc. of the glass fiber F was able to be obtained easily. A value obtained by dividing the square of the diameter value of the cross section of the glass fiber F by the number of texes of the glass fiber bundle composed of the plurality of glass fibers F was 1.22.

  Furthermore, the obtained glass fiber F having a modified cross section is cut into a predetermined length within a range of, for example, 1 mm or more and 20 mm or less to obtain a glass chopped strand having a modified cross section. This glass chopped strand with an irregular cross section has a performance suitable as a reinforcing material for composite materials required to obtain parts with strict dimensional accuracy requirements such as a housing of an electronic control device, and a housing after injection molding The effect of reducing the distortion and improving the strength can be obtained. When the length of the glass chopped strand is shorter than 1 mm, in a use in which the chopped strand and the resin are combined, the shear force acting on the chopped strand in the process where the molten resin and the chopped strand are kneaded depends on the resin. There is a possibility that the chopped strand is further shortened as the reinforcing effect is difficult to obtain. On the other hand, when the length of the chopped strand exceeds 20 mm, the chopped strand is easily clogged when continuously fed while being measured after the chopped strand is stored in the hopper in the process of kneading the molten resin and the chopped strand. There is a risk of impairing discharge from the hopper and continuous supply. From such a viewpoint, the length of the chopped strand is more preferably in the range of 2 mm to 10 mm, and still more preferably in the range of 3 mm to 6 mm.

  FIG. 5 is a longitudinal sectional view schematically showing a modified cross-section glass fiber manufacturing apparatus according to Embodiment 2 of the present invention. In the figure, 80 is a molten glass level gauge, 90 is an observation window, and 91 is an in-furnace monitoring device. In addition, the same code | symbol is attached | subjected about the structure same as Example 1. FIG.

  The difference between the manufacturing apparatus according to the second embodiment and the manufacturing apparatus according to the first embodiment is that the head pressure of the nozzle 10 is adjusted by controlling the depth of the molten glass G in the platinum alloy container 20. It is in the point which was made to do.

  More specifically, a glass level gauge 80 for measuring the depth of the molten glass G is disposed on the furnace wall side surface of the molten glass G of the platinum alloy container 20, and the depth of the molten glass G is measured. Be able to. Specifically, by monitoring which level of the glass level gauge 80 the liquid level of the molten glass G is in the furnace monitoring device 91 from the observation window 90 on the opposite side of the side wall of the molten glass G. The depth of the molten glass G is measured. The observation window 90 has a structure in which a transparent heat-resistant material (for example, transparent heat-resistant glass ceramics) is fitted. Moreover, in this in-furnace monitoring apparatus 91, an image can be preserve | saved as digital data, and the system which accumulate | stores and reuses monitoring data is built.

  The head pressure of the nozzle 10 is adjusted by controlling the depth of the molten glass G according to the measurement result of the glass level gauge 80. For example, if the depth of the molten glass G having a specific gravity of 2.55 is set to 100 ± 5 mm, the head pressure can be adjusted to 2.50 ± 0.125 kPa (that is, 2.375 to 2.625 kPa). For example, when the depth of the molten glass G is 250 mm, the head pressure is 7.5 kPa, and when the depth of the molten glass G is 500 mm, the head pressure is 12.5 kPa.

  As a specific example of the glass fiber F continuously produced by using the manufacturing equipment as described above, the aspect ratio (a / b) of the cross-sectional shape perpendicular to the drawing direction with an equivalent circle diameter of 15 μm, that is, It became a cross-sectional shape extending in the longitudinal direction of a flat shape having a flatness ratio of 4.4. A value obtained by dividing the square of the diameter value of the cross section of the glass fiber F by the tex number of the glass fiber bundle composed of the plurality of glass fibers F was 0.49.

  The obtained glass fiber F having a modified cross section can be used as an application for FRP by forming a glass roving product having a modified cross section after being wound. When a glass roving product having a modified cross section thus obtained is used, a glass fiber reinforced composite having high strength and excellent strength performance can be obtained.

  FIG. 6 is a schematic cross section of the glass fiber F1 obtained by further changing the production conditions such as the temperature of the molten glass G and the flow rate of the molten glass G from the nozzle 10 using the production apparatus of Example 1 described above. The figure is shown.

  This glass fiber F1 has a higher temperature of the molten glass G than that at the time of manufacturing the glass fiber F in Example 1 in which the temperature of the molten glass G flowing out of the nozzle hole 11 is shown in the schematic cross-sectional view of FIG. It is obtained by doing. When a high temperature state is set, the molten glass G that has flowed out of the nozzle hole 11 becomes more easily softened and deformed before being cooled and solidified. As shown in FIG. 2, the nozzle 10 has an outer shape having a protruding portion 10a in which one half of the long axis T direction of the nozzle hole 11 protrudes downward, and thus protrudes downward. The molten glass G that has flowed out from the wall portion of the non-projecting portion on which the cutout portion 10b is formed, on the side facing the protruding portion 10a, is opened to the outside before the molten glass G that has flowed out of the protruding portion 10a. Thus, it tends to become round due to surface tension, and since the viscosity is low, it wraps around the molten glass G flowing out from the protruding portion 10a side to form the convex portions k1 and k2.

  The modified cross-section glass fiber F1 obtained in this way has two convex portions k1 and k2 on a cross section perpendicular to the drawing direction. Moreover, in one specific example of the modified cross-section glass fiber F1, the major axis direction dimension a was 13.1 μm, the minor axis direction dimension b was 4.1 μm, and the flatness ratio was 3.2. Further, in the modified cross-section glass fiber F1, the equivalent circle diameter was 8.50 μm. Furthermore, when the transverse cross section of the irregular cross-section glass fiber F1 is sandwiched between two planes, the shortest diameter at which the plane distance is shortest is 5.1 μm, and the dimension c1 parallel to the shortest diameter of the convex portion k1 is 0.5 μm. It was 9.8% with respect to the shortest diameter. Further, the dimension c2 parallel to the shortest diameter of the convex portion k2 was 1.1 μm, which was 21.6% with respect to the shortest diameter.

  In the modified cross-section glass fiber F2 shown in FIG. 7, concave portions k5 and k6 are formed around the convex portions k3 and k4. The glass fiber F2 is manufactured by increasing the head pressure in addition to increasing the temperature of the molten glass G. Specifically, it is formed by setting the head pressure to 98.1 kPa, increasing the outflow amount of the molten glass G, and further increasing the winding speed of the glass fiber F2. The molten glass G that has flowed out from the wall portion of the non-projecting portion where the notch portion 10b is formed wraps around the projecting portion 10a side, and the molten glass G on the projecting portion 10a side whose cooling rate has been lowered by the wraparound is pulled out at a high speed. A dent will be formed. The modified cross-section glass fiber F2 manufactured under these conditions had a major axis direction dimension a of 29.1 μm, a minor axis dimension b of 4.9 μm, and a flatness ratio of 5.9. The equivalent circle diameter was 14.5 μm.

  Further, when the transverse cross section of the irregular cross-section glass fiber F2 is sandwiched between two parallel straight lines, the shortest diameter at which the distance between the straight lines is the shortest is 6.2 μm, and the size c3 is parallel to the shortest diameter of the convex portion k3. Was 0.7 μm, which was 11.3% with respect to the shortest diameter. Further, the dimension c4 parallel to the minor axis direction dimension b of the convex portion k4 was 1.3 μm, which was 21.0% with respect to the minor axis direction dimension b. Furthermore, the dimension c5 parallel to the shortest diameter of the recess k5 was 0.3 μm, which was 4.8% of the shortest diameter. The dimension c6 parallel to the shortest diameter of the recess k6 was 0.7 μm, which was 11.1% with respect to the shortest diameter. In any case, the flat cross section satisfies the requirement that at least one uneven portion having a height of 3% or more of the shortest diameter of the cross section exists.

  In addition, this invention is not limited to said embodiment, It can implement in a various form.

  For example, if the molten glass G staying in the platinum alloy container 20 stays at 1000 ° C. or higher in the platinum alloy container, the molten glass G can be used as long as the glass composition does not have high temperature chemical reactivity with platinum. However, any ordinary glass fiber material such as E glass, D glass, S glass, AR glass, or C glass may be used. Also, other glass materials may be used as long as they have the desired high-temperature performance.

  The platinum alloy pipe 30 is not limited in its length or cross-sectional size, but an external heat source such as heat generated by electrical energization or a burner may be used to maintain the smooth fluidity of the molten glass G. .

  As a material of the platinum alloy container 20 and the platinum alloy pipe 30, in addition to platinum, ruthenium, rhodium, palladium, osmium, or iridium, zirconium, gold, tungsten, molybdenum, magnesium, calcium, cobalt, tin, zinc, Or what contains elements, such as titanium, can be used, and what has the structure which disperse | distributed ceramic particle | grains etc. may be employ | adopted.

  The volume of the platinum alloy container 20 is not limited as long as it can secure a sufficient volume to continuously supply the molten glass G to the disposed bushing 50. Moreover, you may employ | adopt the thing of a various form also about the shape of the platinum alloy containers 20 as needed. Further, the outer side of the platinum alloy container 20 may be configured to be reinforced or covered with refractory, mortar, or refractory ceramics in order to ensure structural strength, and a refractory board having heat insulating properties may be provided around it. You may employ | adopt suitably the structure wound.

  Regarding the mutual arrangement relationship of the feeder 40, the platinum alloy pipe 30 and the platinum alloy container 20 of the glass melting furnace, the feeder 40 of the glass melting furnace, the platinum alloy pipe 30 as in the first and second embodiments. The platinum alloy container 20 may be disposed in a substantially horizontal relationship with a slight inclination. Alternatively, a structure in which the platinum alloy container 20 is disposed on the lower end side of the platinum alloy pipe 30 that extends substantially vertically downward from the feeder 40 of the glass melting furnace may be used. Further, it may be an intermediate arrangement of these two arrangements of the glass melting furnace feeder 40, the platinum alloy pipe 30 and the platinum alloy container 20. Further, the number of platinum alloy pipes 30 connecting the feeder 40 and the platinum alloy container 20 is not necessarily one.

  As long as the shape of the nozzle hole 11 of the nozzle 10 is flat, the outline does not need to be configured by a straight line, and may have a curved outline.

  The number of the nozzles 10 attached to the bushing 50 can employ a number of nozzles 10 attached to the glass fiber F, F1, and F2 depending on the application used and the amount required to be manufactured. . Moreover, the attachment position to the bushing 50 of the nozzle 10 can also be attached to arbitrary positions. However, the number can be from 100 to 50,000 from the viewpoint of stabilizing the manufacturing quality, and the attachment position of the nozzle 10 to the bushing 50 can be attached at an arbitrary position. That is, they may be arranged in a matrix or in other patterns.

  If the nozzle 10 is made of a platinum alloy, it is possible to use the same material as the material of the platinum alloy container 20 described above, and even if the same material as the platinum alloy container 20 is used, Other materials may be used. In addition, a plurality of nozzles 10 of a plurality of materials may be attached to one bushing 50 according to the arrangement position of the bushing 50 as necessary.

  About the sizing agent which coat | covers the surface of glass fiber F, F1, F2, various sizing agents can be apply | coated according to the use of glass fiber. For example, various silane coupling agents, starch, acrylic, epoxy, urethane, polyester, vinyl acetate, or vinyl acetate / ethylene copolymer can be used in combination as appropriate.

  If the irregular cross-section glass fibers F, F1, and F2 are chopped strands or rovings, they can be applied to many glass fiber reinforced resins, and the shape accuracy of various structural materials can be improved.

  Any method can be adopted as a method for producing chopped strands. Immediately after forming as a long fiber, a bundle of fibers that has been applied and bundled with a bundling agent according to the application can be cut as it is with a cutting device, or after winding the fiber bundle once as a wound body, The fiber bundle may be fed out and cut by a cutting device, or a secondary sizing agent may be applied when cutting. In this case, any method can be adopted as a cutting method. For example, an outer peripheral blade cutting device, an inner peripheral blade cutting device, a hammer mill, or the like can be used. Moreover, it does not specifically limit about the aggregate form of a chopped strand. That is, glass fibers cut to an appropriate length can be laminated in a non-directional direction on a plane and molded with a specific binder, or can be three-dimensionally accumulated in a non-directional direction. . Also, aligned in parallel in a one-dimensional direction, that is, a specific axial direction, and solidified with a predetermined agent, that is, resin or the like (also referred to as glass master batch (GMB) pellet, resin columnar body, LFTP, etc.) ).

  For roving, multiple strands are arranged and bundled, and if they are rolled up in a cylindrical shape with appropriate twills, they can be of any appearance, and the number of aligned strands It is not limited.

  The glass fibers F, F1, and F2 can be used in the form of a continuous strand mat, a bonded mat, a cloth, a tape, a braided fabric, a milled fiber, or the like other than the above. Moreover, it can also be set as the prepreg impregnated with resin. And for usage and molding methods that apply glass fiber, spray-up, hand lay-up, filament winding, injection molding, centrifugal molding, roller molding, or BMC using match die, SMC method, etc. Can do.

  Glass fibers F, F1, and F2 may be used together with resin materials used for various purposes as required. Examples of such applications include electronic equipment-related applications, electronic equipment housing materials, gear tape reels, various storage cases, optical component packages, electronic component packages, switch boxes, insulating supports, etc. , Body roof material (roof material), window frame material, car body front, car body, lamp house, air spoiler, fender grill, tank trolley, ventilator, water tank, filth tank, seat, nose cone, fender grill, curtain, filter Air conditioner ducts, muffler filters, dash panels, fan blades, radiator tires, timing belts, etc.In aircraft related applications, engine covers, air ducts, seat frames, containers, curtains, interior materials, service trays, tires, anti-vibration materials, T There are mining belts, etc., in shipbuilding, land shipping and shipping related applications, motor boats, yachts, fishing boats, domes, buoys, marine containers, floaters, tanks, traffic lights, road signs, curve mirrors, containers, pallets, guardrails, light cover, spark protection There are seats, etc., there are plastic greenhouses, silo tanks, spray nozzles, props, linings, soil conditioners, etc. for agriculture-related applications, and bathtubs, bath toilet units, toilets, septic tanks, water tanks, Interior panel, capsule, valve, knob, wall reinforcement, precast concrete board, flat plate, corrugated sheet, tent, shutter, exterior panel, sash, piping pipe, reservoir, pool, road, structure side wall, concrete formwork, tarpaulin, There are waterproof lining, curing sheet, insect net, etc. For industrial facilities, bug filters, sewer pipes, water purification equipment, anti-vibration concrete reinforcement (GRC), water tanks, belts, chemical tanks, reaction tanks, containers, fans, ducts, corrosion-resistant linings, valves, refrigerators, trays , Freezers, troughs, equipment parts, motor covers, insulation wires, transformer insulation, cable cords, work clothes, curtains, evaporation panels, equipment housings, etc.For leisure sports related applications, fishing rods, skis, archery, golf clubs, There are pools, canoes, surfboards, camera cases, helmets, impact protection armor, flower pots, display boards, etc., and daily necessities related applications include tables, chairs, beds, benches, mannequins, trash cans, portable terminal protection materials, etc.

DESCRIPTION OF SYMBOLS 10 Platinum alloy nozzle 10a Nozzle protrusion part 10b Nozzle notch part 11 Nozzle hole 11a Nozzle hole outline linear part 11b Nozzle hole outline curved part 20 Platinum alloy container (molten glass storage tank)
21 Molten glass upper space 22 in platinum alloy container 22 Pressurized gas introduction pipe 30 Platinum alloy pipe (tube)
40 Feeder 50 Bushing 60 Glass fiber take-up device 70 Cooling pipe 80 Molten glass level gauge 90 Observation window 91 In-furnace monitoring device A Pressurized gas introduction direction F, F1, F2 Modified cross-section glass fiber G Molten glass H Long axis of nozzle hole And planes parallel to the drawing direction of the molten glass k1, k2, k3, k4 Convex portions of the cross section perpendicular to the spinning direction of the irregular shaped glass fiber k5, k6 perpendicular to the spinning direction of the irregular shaped glass fiber Concave section of transverse cross section T Longitudinal axis of nozzle hole cross section W Cooling water a Longitudinal dimension of transverse section perpendicular to spinning direction of irregular section glass fiber b Cross section perpendicular to spinning direction of irregular section glass fiber Dimensions in the minor axis direction c1, c2, c3, c4 Dimensions in parallel to the minor axis direction of the convex portion of the transverse section perpendicular to the spinning direction of the irregular shaped glass fiber c5, c6 How to spin the irregular shaped glass fiber Dimension parallel to the minor axis direction of the concave part of the cross section perpendicular to the direction

Claims (8)

A nozzle having a flat nozzle hole having a major axis and a minor axis perpendicular to the major axis is provided at the bottom of the molten glass reservoir in which the molten glass is stored, and the molten glass is drawn out from the nozzle hole of the nozzle. That is, a method for producing a modified cross-section glass fiber that produces a modified cross-section glass fiber whose cross section perpendicular to the drawing direction forms a flat shape,
The nozzle having a protruding portion that protrudes along the pulling-out direction from the peripheral portion of the nozzle hole that is not more than half a circumference of the nozzle hole at the front end of the nozzle hole as a boundary is used as the nozzle. Manufacturing method of glass fiber.   The method for producing a modified cross-section glass fiber according to claim 1, wherein a head pressure of the nozzle when the glass fiber is drawn from the nozzle is in a range of 2 kPa to 500 kPa.   The method for producing a modified cross-section glass fiber according to claim 2, wherein a head pressure of the nozzle is adjusted by pressurizing a liquid surface of the molten glass stored in the molten glass storage tank.   The method for producing a modified cross-section glass fiber according to claim 2, wherein a head pressure of the nozzle is adjusted by controlling a depth of the molten glass stored in the molten glass storage tank. An irregular cross-section glass fiber produced by the method for producing an irregular cross-section glass fiber according to any one of claims 1 to 4,
An irregular cross-section glass fiber having a flatness ratio of the cross section of 1.5 or more and 10.0 or less.   The modified cross-section glass fiber according to claim 5, wherein one or more convex portions or concave portions are formed in an outline of the cross section.   The modified cross-section glass fiber according to claim 5 or 6, wherein the equivalent circle diameter is 3 µm or more and 40 µm or less. A nozzle having a flat nozzle hole having a major axis and a minor axis perpendicular to the major axis is provided at the bottom of the molten glass reservoir in which the molten glass is stored, and the molten glass is drawn out from the nozzle hole of the nozzle. That is, an apparatus for producing a modified cross-section glass fiber for producing a modified cross-section glass fiber whose cross section perpendicular to the drawing direction forms a flat shape,
An apparatus for producing a modified cross-section glass fiber, characterized in that a protruding portion that protrudes along the drawing direction from a peripheral portion of a nozzle hole that is not more than a half circumference with a major axis of the nozzle hole as a boundary is provided at a tip portion of the nozzle. .

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