Method and apparatus for manufacturing glass fibers

Abstract

The present invention provides a method and apparatus for manufacturing glass fibers that can suppress the occurrence of defective products. [Solution] The present invention provides a method for manufacturing glass fibers, comprising: a coating step of applying a sizing agent Z stored in a storage tank 14 to a plurality of glass filaments F drawn out from a bushing 12 using an applicator roller 13; and a bundling step of bundling the plurality of glass filaments F coated with the sizing agent Z to form a glass strand S, wherein the storage tank 14 is connected to an inlet 15a into which the sizing agent Z flows and an outlet 15b into which the sizing agent Z flows out, and in the coating step, the amount of sizing agent Z flowing in and out of the storage tank 14 is measured while the liquid level height of the sizing agent Z stored in the storage tank 14 is controlled to be within a certain range, the amount of sizing agent Z flowing in and out of the sizing agent Z is measured, the theoretical amount of sizing agent Z to be applied is calculated from the difference between the amount of inflow and the amount of outflow, and the rotation speed of the applicator roller 13 is controlled based on the theoretical amount of application.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing glass fibers and an apparatus for manufacturing glass fibers.

Background Art

[0002] In a conventional method for manufacturing glass fibers, a sizing agent is applied to a plurality of glass filaments drawn from a bushing using an applicator, and then gathered by a gathering shoe to form a glass strand (for example, Patent Document 1).

[0003] The formed glass strand is wound around a cylindrical collet to form a glass fiber wound body or directly cut to form glass chopped strands.

Prior Art Documents

Patent Documents

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the method for manufacturing glass fibers as described above, due to the influence of the accompanying air flow and the outside air temperature during the spinning of the glass filaments, the ambient temperature around the applicator and the temperature of the sizing agent change. As a result, not only does the application amount of the sizing agent to the glass filaments vary over time, but a film in which the sizing agent has solidified is formed on the surface of the roller provided on the applicator, making it difficult to apply the sizing agent evenly to the glass filaments.

[0006] If the sizing agent is not properly applied to the glass filament, quality problems such as increased fuzziness in the glass strand and adverse effects on the properties of the composite material when combined with resin or cement may occur. Therefore, from the perspective of suppressing the occurrence of defective products, it is necessary to apply the sizing agent evenly to the glass filament and control the amount applied within an appropriate range.

[0007] The object of the present invention is to provide a method for manufacturing glass fibers and a manufacturing apparatus that can suppress the occurrence of defective products. [Means for solving the problem]

[0008] A method for manufacturing glass fibers according to Embodiment 1 of the present invention comprises a coating step of applying a sizing agent stored in a storage tank to a plurality of glass filaments drawn from a bushing using an applicator roller, and a bundling step of bundling the plurality of glass filaments coated with the sizing agent to form a glass strand, wherein the storage tank is connected to an inlet for the sizing agent to flow in and an outlet for the sizing agent to flow out, and in the coating step, the amount of the sizing agent flowing into the storage tank and the amount of the sizing agent flowing out of the storage tank are measured while the liquid level of the sizing agent stored in the storage tank is controlled to be within a certain range, the theoretical amount of the sizing agent to be applied to the plurality of glass filaments is calculated from the difference between the amount of the inlet and the amount of the outlet, and the rotation speed of the applicator roller is controlled based on the theoretical amount of application.

[0009] The amount of sizing agent applied to the glass filament can be intentionally varied by controlling the rotation speed of the applicator roller. Specifically, reducing the rotation speed of the applicator roller reduces the amount of sizing agent applied to the glass filament, while increasing the rotation speed increases the amount of sizing agent applied. Therefore, by changing the rotation speed of the applicator roller based on the theoretical application amount calculated from the difference between the inflow and outflow rates of sizing agent to the storage tank, the amount of sizing agent applied to the glass filament can be appropriately controlled.

[0010] In the glass fiber manufacturing method according to Embodiment 2, in the coating step of Embodiment 1, it is preferable to decrease the rotation speed of the applicator roller when the theoretical coating amount is greater than the reference value, and to increase the rotation speed of the applicator roller when the theoretical coating amount is less than the reference value. This makes it easier to evenly coat the glass filament with the sizing agent and to control the coating amount within an appropriate range.

[0011] In the glass fiber manufacturing method according to Embodiment 3, in the coating step of Embodiment 1, it is preferable to reduce the rotation speed of the applicator roller when the theoretical coating amount is greater than the upper limit of the reference range, and to increase the rotation speed of the applicator roller when the theoretical coating amount is less than the lower limit of the reference range. This makes it easier to evenly coat the glass filament with the sizing agent and to control the coating amount within an appropriate range.

[0012] In the glass fiber manufacturing method according to Embodiment 4, it is preferable to measure the inflow and outflow amounts by a sensor during the coating step of any of Embodiments 1 to 3. In this way, the inflow amount of sizing agent supplied to the storage tank and the outflow amount of sizing agent discharged from the storage tank can be measured suitably and easily.

[0013] A glass fiber manufacturing apparatus according to aspect 5 of the present invention comprises a bushing from which a plurality of glass filaments are drawn out, an applicator roller for applying a sizing agent to the plurality of glass filaments, a storage tank capable of storing the sizing agent, an inlet for the sizing agent and an outlet for the sizing agent connected to the storage tank, and a gathering shoe for gathering the plurality of glass filaments to which the sizing agent has been applied, further comprising a measuring unit for measuring the amount of sizing agent flowing into the storage tank and the amount of sizing agent flowing out from the storage tank, and a rotation speed control unit for controlling the rotation speed of the applicator roller based on the theoretical amount of sizing agent to be applied to the plurality of glass filaments, which is calculated from the difference between the amount of inlet and the amount of outlet. According to the glass fiber manufacturing apparatus of the present invention, the same effects as the glass fiber manufacturing method of the present invention described above can be obtained.

[0014] In the glass fiber manufacturing apparatus according to embodiment 6 of the present invention, in embodiment 5, the measuring unit preferably includes an inflow rate measuring unit for measuring the inflow rate and an outflow rate measuring unit for measuring the outflow rate. In this way, the inflow rate of the sizing agent supplied to the storage tank and the outflow rate discharged from the storage tank can be measured suitably and easily. [Effects of the Invention]

[0015] According to the glass fiber manufacturing method and manufacturing apparatus of the present invention, it is possible to suppress the occurrence of defective products. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic front view showing a glass fiber manufacturing apparatus according to the first embodiment of the present invention. [Figure 2] This is a schematic side view showing a glass fiber manufacturing apparatus according to the first embodiment of the present invention. [Figure 3] Figure 3 is an enlarged schematic cross-sectional view showing the point in Figure 2 where the applicator roller comes into contact with the liquid surface of the sizing agent in the storage tank. [Figure 4] FIG. 4 is a flowchart for explaining control in the glass fiber manufacturing apparatus according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a schematic side view showing a glass fiber manufacturing apparatus according to the second embodiment of the present invention. **[Embodiments for Carrying Out the Invention]**

[0017] Hereinafter, preferred embodiments of the present invention will be described. However, the following embodiments are merely illustrative, and the present invention is not limited to the following embodiments. In each drawing, for convenience of explanation, a part of the configuration may be exaggerated or simplified. Also, the dimensional ratios of each part may be different from the actual ones. In addition, in each drawing, members having substantially the same function may be referred to by the same reference numerals.

[0018] (First Embodiment) Hereinafter, first, an example of a manufacturing apparatus used in the glass fiber manufacturing method of the present invention will be described.

[0019] (Glass Fiber Manufacturing Apparatus) As shown in FIGS. 1 and 2, the glass fiber manufacturing apparatus 11 according to the first embodiment includes a bushing 12, an applicator roller 13, a storage tank 14, an inflow part 15a, an outflow part 15b, a gathering shoe 16, a measuring part 17, and a rotational speed control part 18.

[0020] Although not shown in the drawings, the glass fiber manufacturing apparatus 11 may further include a traverse for reciprocating the glass strand S and a collet for winding up the glass strand S that has passed through the traverse to form a glass fiber winding body.

[0021] Also, although not shown in the drawings, the glass fiber manufacturing apparatus 11 may further include a cutting part for directly cutting the glass strand S.

[0022] The bushing 12 is a box-shaped container having multiple nozzles at its bottom, through which molten glass is supplied and multiple glass filaments F are drawn out downward from the nozzles. In the drawing, only the outermost part of the multiple glass filaments F is shown, illustrating the range through which the glass filaments F pass.

[0023] The applicator roller 13 rotates while in contact with multiple glass filaments F, and is a device that applies a sizing agent Z to the multiple glass filaments F.

[0024] The storage tank 14 is a device for storing the stimulant Z and is located near the applicator roller 13. The storage tank 14 is equipped with an inlet 14a into which the stimulant Z flows and an outlet 14b into which the stimulant Z flows out, and the inlet 14a is connected to the inlet section 15a, and the outlet 14b is connected to the outlet section 15b.

[0025] The shape and configuration of the inlet 15a and outlet 15b are not particularly limited, as long as the sizing agent Z can flow through them. In this embodiment, the inlet 15a and outlet 15b are pipe-shaped. Preferably, the inlet 15a and outlet 15b are connected to each other, and the sizing agent Z is circulated outside the storage tank 14. In this case, a filter may be provided between the inlet 15a and outlet 15b to remove impurities generated or mixed into the sizing agent Z. The inlet 15a and outlet 15b may also be connected to each other via a sizing agent storage facility (not shown), and the sizing agent Z may be circulated through this facility.

[0026] The gathering shoe 16 is a device that bundles and gathers multiple glass filaments F coated with a sizing agent Z to form a glass strand S. Alternatively, the gathering shoe 16 may be configured to divide the multiple glass filaments F into sections of multiple filaments each, thereby forming multiple glass strands S.

[0027] Glass filaments F and glass strands S are composed of, for example, E glass (general-purpose alkali-free glass), A glass (alkali-resistant glass), C glass (acid-resistant alkali-lime-containing glass), D glass (low dielectric constant glass), S glass (high-strength, high-modulus glass), T glass (high-strength, high-modulus glass), H glass (high dielectric constant glass), etc.

[0028] The measuring unit 17 is a device that measures the amount of sizing agent Z flowing into the storage tank 14 and the amount of sizing agent Z flowing out of the storage tank 14. In this embodiment, the measuring unit 17 is provided near the inlet and outlet, but is not limited to this. The measuring unit 17 measures the inlet and outlet amounts using a sensor, such as a flow sensor.

[0029] Furthermore, it is preferable that the measuring unit 17 includes an inflow rate measuring unit 17a for measuring the inflow rate of the stimulant Z, and an outflow rate measuring unit 17b for measuring the outflow rate of the stimulant Z. With this configuration, the inflow rate of the stimulant Z supplied to the storage tank 14 and the outflow rate discharged from the storage tank 14 can be measured conveniently and easily.

[0030] The rotational speed control unit 18 controls the rotational speed of the applicator roller 13 based on the theoretical amount of sizing agent Z applied to the glass filament F, which is calculated, for example, from the difference between the amount of sizing agent Z flowing in and out, as measured by the measurement unit 17.

[0031] The rotational speed control unit 18 includes, for example, a control unit 18a that outputs a measurement value from the measuring unit 17, and a power supply 18b connected to the applicator roller 13. The applicator roller 13 rotates when voltage is applied by the power supply 18b. The rotational speed control unit 18 can control the rotational speed of the applicator roller 13 by applying voltage to the applicator roller 13 through the power supply 18b. Specifically, the rotational speed control unit 18 compares the theoretical application amount of the sizing agent Z with a preset reference value D, and when the theoretical application amount is greater than the reference value D, it reduces the rotational speed of the applicator roller 13. Alternatively, the rotational speed control unit 18 compares the theoretical application amount of the sizing agent Z with a preset reference range Dr, and when the theoretical application amount is greater than the upper limit of the reference range Dr, it reduces the rotational speed of the applicator roller 13. When the theoretical application amount of the sizing agent Z is less than the reference value D, it increases the rotational speed of the applicator roller 13. Similarly, when the theoretical application amount of the sizing agent Z is less than the lower limit of the reference range Dr, the rotation speed of the applicator roller 13 is increased. The reason for controlling the rotation speed of the applicator roller 13 in this way is explained below.

[0032] Figure 3 is an enlarged schematic cross-sectional view showing the point where the applicator roller 13 and the liquid surface of the sizing agent Z come into contact. Here, the applicator roller 13 rotates in the flow direction of the glass filament F (direction R in Figure 3). Therefore, in the storage tank 14, the sizing agent Z adhering to the surface of the applicator roller 13 moves to the glass filament F as the applicator roller 13 rotates and adheres to the surface of the glass filament F. As the applicator roller 13 rotates in the R direction, it lifts the sizing agent Z adhering to its surface upward (direction a in Figure 3). On the other hand, a portion of the sizing agent Z lifted upward hangs down (direction b in Figure 3) due to gravity and returns to the storage tank 14. In this way, only a portion of the sizing agent Z adhering to the surface of the applicator roller 13 reaches the glass filament F while remaining attached to the surface of the applicator roller 13 and is applied to the glass filament F. Here, when the rotation speed of the applicator roller 13 is high, the ratio of the amount of sizing agent Z lifted in direction a to the amount of sizing agent Z hanging down becomes high, resulting in a larger amount of sizing agent Z reaching the glass filament F and a larger amount of sizing agent Z adhering to the glass filament F. On the other hand, when the rotation speed of the applicator roller 13 is low, the ratio of the amount of sizing agent Z lifted in direction a to the amount of sizing agent Z hanging down in direction b becomes low, resulting in a smaller amount of sizing agent Z reaching the glass filament F and a smaller amount of sizing agent Z adhering to the glass filament F.

[0033] Next, an example of a method for producing glass fibers using the glass fiber manufacturing apparatus 11 of the present invention will be described.

[0034] (Method of manufacturing glass fibers) The method for manufacturing glass fibers according to this embodiment includes a coating step of applying a sizing agent Z stored in a storage tank 14 to a plurality of glass filaments F drawn out from a bushing 12 using an applicator roller 13, and a bundling step of bundling the plurality of glass filaments F coated with the sizing agent Z to form a glass strand S.

[0035] (Coating process) In the coating process, the liquid level of the sizing agent Z stored in the storage tank 14 is controlled to remain within a certain range. The method for controlling the liquid level is not particularly limited, but for example, by keeping the inflow rate constant, measuring the liquid level using a liquid level sensor (not shown), and controlling the outflow rate according to the measured liquid level, the liquid level can be controlled to remain within a certain range.

[0036] Furthermore, the inflow rate measuring unit 17a and the outflow rate measuring unit 17b measure the inflow rate of sizing agent Z flowing into the storage tank 14 and the outflow rate of sizing agent Z flowing out of the storage tank 14, respectively, and output the measured values ​​to the rotation speed control unit 18. The rotation speed control unit 18 calculates the theoretical coating amount of sizing agent Z for multiple glass filaments F based on the difference between the measured inflow rate and outflow rate, and controls the rotation speed of the applicator roller 13 based on this theoretical coating amount. The reason why the theoretical coating amount can be calculated by the above method is explained below.

[0037] When the sizing agent Z flows into the storage tank 14, the liquid level increases by an amount equivalent to the inflow. On the other hand, in the coating process, since the sizing agent Z is coated onto multiple glass filaments F, the liquid level decreases by an amount equivalent to the theoretical coating amount. As described above, in this embodiment, the liquid level of the sizing agent Z stored in the storage tank 14 is controlled to remain within a certain range. In this case, the liquid level can be controlled to remain within a certain range by setting the outflow amount to the amount equivalent to the inflow minus the amount equivalent to the theoretical coating amount. That is, when the liquid level of the sizing agent Z stored in the storage tank 14 is controlled to remain within a certain range, the theoretical coating amount can be calculated from the difference between the inflow and outflow amounts of the sizing agent Z.

[0038] Figure 4 shows a flowchart relating to the rotational speed of the applicator roller 13 by the rotational speed control unit 18. In step S1, the rotational speed control unit 18 determines whether a preset reference value D and the theoretical coating amount are equal. If the reference value D and the theoretical coating amount are equal (step S1: YES), the rotational speed control unit 18 maintains the voltage applied from the power supply 18b to the applicator roller 13 and terminates the process. On the other hand, if the reference value D and the theoretical coating amount are different values ​​(step S1: NO), the process proceeds to step S2.

[0039] In step S2, the rotational speed control unit 18 compares a preset reference value D with the theoretical coating amount. If the theoretical coating amount is greater than the reference value D (step S2: YES), the process proceeds to step S3.

[0040] In step S3, the rotational speed control unit 18 reduces the rotational speed of the applicator roller 13 by decreasing the voltage applied from the power supply 18b to the applicator roller 13. When the rotational speed of the applicator roller 13 is reduced, the amount of sizing agent Z applied to the glass filament F can be reduced by the mechanism described above.

[0041] In step S2, if the theoretical coating amount is less than the reference value D (step S2: NO), the process proceeds to step S4. In step S4, the rotational speed control unit 18 increases the rotational speed of the applicator roller 13 by increasing the voltage applied to the applicator roller 13. When the rotational speed of the applicator roller 13 increases, the amount of sizing agent Z applied to the glass filament F can be increased by the mechanism described above.

[0042] (Second embodiment) Next, a glass fiber manufacturing apparatus and manufacturing method according to a second embodiment of the present invention will be described. Only configurations that differ from the embodiments described above will be described.

[0043] Figure 5 is a schematic side view showing a glass fiber manufacturing apparatus 21 according to a second embodiment of the present invention. Compared to the glass fiber manufacturing apparatus 11 described above, the glass fiber manufacturing apparatus 21 further includes a collection unit 19 for collecting the sizing agent Z overflowing from the storage tank 14, a collected liquid outlet unit 20 connected to the collection unit 19, and an outlet volume measuring unit 17b provided near the collected liquid outlet unit 20.

[0044] The collection unit 19 is a device for collecting the sizing agent Z that overflows from the storage tank 14. The collection unit 19 is connected to a collection liquid outlet 20. The sizing agent Z collected here may be returned to the storage tank 14 from the inlet 15a via a circulation mechanism.

[0045] The collected liquid outlet section 20 discharges the sizing agent Z collected in the collection section 19. The shape and configuration of the collected liquid outlet section 20 are not particularly limited, as long as the sizing agent Z can flow through it. In the second embodiment, the collected liquid outlet section 20 is pipe-shaped. It is also preferable that the collected liquid outlet section 20 is connectable to the outlet section 15b. In this way, the sizing agent Z that overflows from the storage tank 14 can be efficiently reused.

[0046] An outflow rate measuring unit 17b, located near the collected liquid outflow section 20, measures the flow rate of the sizing agent Z flowing through the collected liquid outflow section 20. The measured flow rate of the sizing agent Z is output to the rotation speed control unit 18 as the outflow amount of the sizing agent Z discharged from the storage tank 14.

[0047] In the glass fiber manufacturing method using the glass fiber manufacturing apparatus 21, the storage tank 14 is filled with a sizing agent Z, and the liquid level is controlled to be constant by overflowing the sizing agent Z that exceeds the capacity of the storage tank 14.

[0048] The overflowing sizing agent Z is collected in the collection unit 19. The flow rate of the sizing agent Z collected by the collection unit 19 and flowing through the collection liquid outlet unit 20 is measured by the outlet amount measurement unit 17b and output to the rotation speed control unit 18. Furthermore, the flow rate of the sizing agent Z flowing through the collection liquid outlet unit 20, together with the flow rate of the sizing agent Z flowing through the outlet unit 15b, is output to the rotation speed control unit 18 as the amount of sizing agent Z discharged from the storage tank 14. Thus, the theoretical coating amount of sizing agent Z for multiple glass filaments F can be calculated in the same manner as described above.

[0049] The first and second embodiments can be implemented with the following modifications. These embodiments and the following modifications can be combined with each other to the extent that they do not contradict the technical standards.

[0050] The glass fiber manufacturing method of this embodiment may further include a cutting step of cutting the glass strand S to form a glass chopped strand.

[0051] The glass fiber manufacturing method of this embodiment may further include a winding step of winding a glass strand S onto a collet to form a glass fiber winding body.

[0052] The glass fiber manufacturing method of this embodiment may be configured to include a cutting step immediately after the glass strand S is formed in the bundling step.

[0053] The configuration in which data based on measurements by the measurement unit 17 is output directly from the measurement unit 17 to the rotational speed control unit 18 is not limited to this configuration. For example, a processing unit for processing measurement data may be provided, and the data may be output from the measurement unit 17 to the rotational speed control unit 18 via the processing unit.

[0054] The method for measuring the inflow and outflow rates in the measurement unit 17 may be other than using a sensor.

[0055] The embodiments and modifications disclosed herein are illustrative in all respects and are not limited to these examples of the present invention. That is, the scope of the present invention is indicated by the claims and is intended to include all modifications in the sense and scope equivalent to the claims. [Explanation of symbols]

[0056] 11, 21... Glass fiber manufacturing equipment 12…Bushing 13…Applicator Roller 14…Storage tank 15a...Inflow part 15b...Outflow part 16... Gathering Shoe 17…Measuring part 17a...Inflow measurement part 17b...Outflow measurement section 18…Rotation speed control unit 19…Collection Department 20...Collection liquid outlet F...Glass filament S...Glass Strand

Claims

1. A coating step in which a sizing agent stored in a storage tank is applied to multiple glass filaments drawn out from a bushing using an applicator roller, A method for manufacturing glass fibers, comprising a bundling step of bundling together the plurality of glass filaments coated with the sizing agent to form a glass strand, The storage tank is connected to an inlet into which the sizing agent flows and an outlet into which the sizing agent flows out. In the coating process, while controlling the liquid level of the sizing agent stored in the storage tank to remain within a certain range, the amount of sizing agent flowing into the storage tank and the amount of sizing agent flowing out of the storage tank are measured, and the theoretical amount of sizing agent to be coated onto the plurality of glass filaments is calculated from the difference between the amount of inflow and the amount of outflow. Based on the theoretical coating amount, the rotation speed of the applicator roller is controlled. A method for manufacturing glass fibers.

2. The method for manufacturing glass fibers according to claim 1, wherein, in the coating step, when the theoretical coating amount is greater than a reference value, the rotation speed of the applicator roller is reduced, and when the theoretical coating amount is less than the reference value, the rotation speed of the applicator roller is increased.

3. The method for manufacturing glass fibers according to claim 1, wherein, in the coating step, when the theoretical coating amount is greater than the upper limit of the reference range, the rotation speed of the applicator roller is reduced, and when the theoretical coating amount is less than the lower limit of the reference range, the rotation speed of the applicator roller is increased.

4. A method for manufacturing glass fibers according to any one of claims 1 to 3, wherein in the coating step, the amount of inflow and the amount of outflow are measured by a sensor, respectively.

5. A bushing from which multiple glass filaments are drawn, An applicator roller for applying a sizing agent to the plurality of glass filaments, A storage tank capable of storing the aforementioned sizing agent, Connected to the storage tank are an inlet into which the sizing agent flows and an outlet into which the sizing agent flows out, A glass fiber manufacturing apparatus comprising: a gathering shoe for gathering the plurality of glass filaments coated with the sizing agent, A measuring unit that measures the amount of the sizing agent flowing into the storage tank and the amount of the sizing agent flowing out of the storage tank, The system further comprises a rotational speed control unit that controls the rotational speed of the applicator roller based on the theoretical amount of the sizing agent applied to the plurality of glass filaments, calculated from the difference between the inflow rate and the outflow rate. Glass fiber manufacturing equipment.

6. The glass fiber manufacturing apparatus according to claim 5, wherein the measuring unit includes an inflow rate measuring unit for measuring the inflow rate and an outflow rate measuring unit for measuring the outflow rate.

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