Fiber diameter measuring device, inorganic fiber sheet manufacturing device, fiber diameter measuring method, and inorganic fiber sheet manufacturing method

Abstract

The purpose of the present invention is to provide a fiber-diameter-measuring device, a device for manufacturing an inorganic fiber sheet, a method for measuring a fiber diameter, and an method for measuring an inorganic fiber sheet, with which it is possible to guarantee the continuous safety of the fiber diameter of an inorganic fiber in an inorganic fiber sheet and further measure the fiber diameter of the inorganic fiber in the inorganic fiber sheet even during the manufacture of the inorganic fiber sheet, not just after the manufacture of the inorganic fiber sheet.　The present invention provides a fiber-diameter-measuring device for measuring the fiber diameter of an inorganic fiber in an inorganic fiber sheet (1) that contains the inorganic fiber, the fiber-diameter-measuring device being characterized by being provided with a sample collection means (2) for collecting a prescribed quantity of the inorganic fiber in the whole area of the inorganic fiber sheet (1), and a measurement means (3) for measuring the fiber diameter of the collected inorganic fiber.

Description

Technical Field

[0001] The present invention relates to a fiber diameter measuring device for measuring the fiber diameter of inorganic fibers in an inorganic fiber sheet, a manufacturing device for an inorganic fiber sheet using the same, a fiber diameter measuring method, and a manufacturing method for an inorganic fiber sheet.

Background Art

[0002] Inorganic fiber molded bodies are widely used in applications exposed to high temperatures such as industrial heat insulating materials, refractory materials, and packing materials. In recent years, inorganic fiber molded bodies are wound around exhaust gas treatment bodies when accommodating exhaust gas treatment bodies such as catalyst carriers and particulate filters in a metal casing as cushioning materials for automobile exhaust gas purification devices, that is, they are also used as holding materials for exhaust gas purification devices interposed between the exhaust gas treatment bodies and the casing.

[0003] However, ceramic fibers are said to have a risk of health hazards such as carcinogenicity, and regulations on inorganic fibers have been strengthened.

[0004] As an index of the safety of inorganic fiber molded bodies, for example, there is the fiber diameter of inorganic fibers in the inorganic fiber molded body. For example, the World Health Organization (WHO) refers to fibrous substances inhaled into the body with human respiration and reaching the lungs as "inhalable fibers", and defines them as having a length exceeding 5 μm, a diameter less than 3 μm, and an aspect ratio (ratio of length to diameter) exceeding 3.

[0005] Generally, when measuring the fiber diameter of inorganic fibers in a sheet-shaped inorganic fiber formed body (inorganic fiber sheet), a method is performed in which a part of the inorganic fiber sheet is punched out or cut out to collect a test piece having a predetermined size, and the fiber diameter of the inorganic fibers in the test piece is measured (see, for example, Non-Patent Document 1). The above method is based on the assumption that if the manufacturing conditions of the inorganic fiber sheet are constant, the average fiber diameter, fiber diameter distribution, etc. of the inorganic fiber sheet will also be the same. However, in the above method, it cannot be asserted that the reliability of the fiber diameter is guaranteed for lots or parts that have not been measured. Therefore, there is a need for a measurement method that guarantees the continuity and uniformity of the average fiber diameter, fiber diameter distribution, etc. over the entire area of the inorganic fiber sheet. In other words, it is necessary to guarantee that the safety of the fiber diameter is ensured over the entire area of the inorganic fiber sheet, that is, to guarantee the continuous safety of the fiber diameter of the inorganic fibers in the inorganic fiber sheet.

[0006] Also, in the above method, since a part of the inorganic fiber sheet is punched out or cut out for sample collection, the inorganic fiber sheet after sample collection cannot be used as a product.

[0007] Furthermore, the above method is a method for measuring the fiber diameter offline after the production of the inorganic fiber sheet, and it is not possible to measure the fiber diameter online during the production of the inorganic fiber sheet. In particular, in the case of a long inorganic fiber sheet, with the above offline method, it is only possible to confirm the fiber diameter at the site punched out or cut out as a test piece. Therefore, a technique for measuring the fiber diameter with respect to the entire width and length of the long inorganic fiber sheet is important.

Prior Art Documents

Non-Patent Documents

[0008]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] In view of such problems, the present inventors have been studying a method that can guarantee the accuracy of the fiber diameter measurement in the measurement of the fiber diameter, can be used as a product even after the measurement of the fiber diameter, and can measure the fiber diameter online during the production of the inorganic fiber sheet rather than offline as described above. However, an effective method for such a method has not yet been established.

[0010] The present invention has been made in view of the above problems, and can guarantee the continuity and uniformity of the fiber diameter of the inorganic fibers in the inorganic fiber sheet, and can also guarantee the continuous safety of the fiber diameter of the inorganic fibers in the inorganic fiber sheet. Furthermore, an object of the present invention is to provide a fiber diameter measuring device, an inorganic fiber sheet manufacturing device, a fiber diameter measuring method, and an inorganic fiber sheet manufacturing method capable of measuring the fiber diameter of the inorganic fibers in the inorganic fiber sheet not only after the production of the inorganic fiber sheet but also during the production of the inorganic fiber sheet.

Means for Solving the Problems

[0011] In order to achieve the above object, the present invention provides a fiber diameter measuring device for measuring the fiber diameter of inorganic fibers in an inorganic fiber sheet containing inorganic fibers, comprising: a sample collecting means capable of collecting a predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet; and a measuring means for measuring the fiber diameter of the collected inorganic fibers. Optionally, the sample collecting means may include a sample moving means for moving the inorganic fibers, a pretreatment means for assisting the collection of the inorganic fibers, and a sample recovery means for recovering the inorganic fibers.

[0012] According to the present invention, in the sample collection means, a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet. Therefore, the collected inorganic fibers can be regarded as representative of the inorganic fibers in the inorganic fiber sheet. Accordingly, the accuracy of the measured fiber diameter of the inorganic fibers can be improved. Further, in the sample collection means, since the inorganic fiber sheet is not punched out or cut out for sample collection, the fiber diameter of the inorganic fibers in the inorganic fiber sheet can be measured online. Furthermore, the inorganic fiber sheet can be prevented from being damaged in appearance by the measurement of the fiber diameter, and can be used as a product even after the measurement of the fiber diameter.

[0013] In the present invention, the sample collection means may be disposed on one or both sides of the inorganic fiber sheet and may include a sample moving means for moving the inorganic fibers. In this case, the sample moving means can be a suction means for sucking the inorganic fibers.

[0014] Also, in the present invention, the sample collection means may include a pretreatment means for assisting in the collection of the inorganic fibers. In this case, the pretreatment means can be a physically non-contact means that is physically non-contact with the inorganic fiber sheet. Also in this case, the physically non-contact means can be a supply means for supplying a gas or a liquid to the inorganic fiber sheet from one or both sides of the inorganic fiber sheet. Further, the pretreatment means may be a physically contact means that is physically in contact with the inorganic fiber sheet.

[0015] Also, in the present invention, the sample collection means may include a vibration means for applying vibration to the inorganic fiber sheet as the pretreatment means.

[0016] Also, in the present invention, the sample collection means can include a sample recovery means for recovering the inorganic fibers.

[0017] The present invention also provides a manufacturing apparatus for an inorganic fiber sheet, which includes the above-described fiber diameter measuring apparatus.

[0018] According to the present invention, by providing the above-described fiber diameter measuring device, the accuracy of the measured fiber diameter of the inorganic fiber can be improved. Further, by providing the above-described fiber diameter measuring device, the fiber diameter of the inorganic fiber in the inorganic fiber sheet can be measured online. Furthermore, it is possible to confirm the variation in the fiber diameter of the inorganic fiber and the deviation from the allowable range online, and by feeding back the result to the manufacturing process of the inorganic fiber sheet or the like and controlling the manufacturing conditions of the inorganic fiber sheet or the like, the fiber diameter of the inorganic fiber can be kept within a predetermined standard range. Also, by providing the above-described fiber diameter measuring device, an inorganic fiber sheet having a good appearance can be obtained even after the fiber diameter measurement.

[0019] The manufacturing apparatus of the inorganic fiber sheet of the present invention preferably includes a firing means for continuously firing an inorganic fiber precursor sheet containing an inorganic fiber precursor on the upstream side of the above-described fiber diameter measuring device. This is because the present invention is useful for manufacturing a long inorganic fiber sheet.

[0020] The present invention also provides a fiber diameter measuring method for measuring the fiber diameter of the inorganic fiber in an inorganic fiber sheet containing the inorganic fiber, the method including a sample collection step of collecting a predetermined amount of the inorganic fiber from the inorganic fiber sheet by a collection method capable of collecting the inorganic fiber over the entire area of the inorganic fiber sheet, and a measurement step of measuring the fiber diameter of the collected inorganic fiber.

[0021] According to the present invention, in the sample collection step, since a predetermined amount of inorganic fiber can be collected over the entire area of the inorganic fiber sheet, the accuracy of the measured fiber diameter of the inorganic fiber can be improved. Also, since the inorganic fiber sheet is not punched out or cut out for sample collection, the fiber diameter of the inorganic fiber in the inorganic fiber sheet can be measured online. Furthermore, the appearance of the inorganic fiber sheet can be prevented from being impaired by the fiber diameter measurement, and it can be used as a product even after the fiber diameter measurement.

[0022] In the present invention, in the above sample collection step, the inorganic fibers may be moved by sample moving means that is disposed on one or both sides of the inorganic fiber sheet and moves the inorganic fibers. Further, in the present invention, in the above sample collection step, the collection of the inorganic fibers may be assisted by pretreatment means for assisting the collection of the inorganic fibers.

[0023] Furthermore, the present invention provides a method for manufacturing an inorganic fiber sheet, which includes a sample collection step of collecting a predetermined amount of the inorganic fibers over the entire area of an inorganic fiber sheet containing inorganic fibers, and a measurement step of measuring the fiber diameter of the collected inorganic fibers.

[0024] According to the present invention, in the sample collection step, since a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet, the accuracy of the measured fiber diameter of the inorganic fibers can be improved. Also, since the inorganic fiber sheet is not punched out or cut out for sample collection, the fiber diameter of the inorganic fibers in the inorganic fiber sheet can be measured online. Further, an inorganic fiber sheet with a good appearance can be obtained even after the fiber diameter measurement.

[0025] In the present invention, in the above sample collection step, the inorganic fibers may be moved by sample moving means that is disposed on one or both sides of the inorganic fiber sheet and moves the inorganic fibers. Further, in the present invention, in the above sample collection step, the collection of the inorganic fibers may be assisted by pretreatment means for assisting the collection of the inorganic fibers.

[0026] Also, the method for manufacturing an inorganic fiber sheet of the present invention preferably includes a preparation step of preparing an inorganic fiber precursor sheet containing an inorganic fiber precursor before the above sample collection step, and a firing step of continuously firing the inorganic fiber precursor sheet to obtain the inorganic fiber sheet. This is because the present invention is useful for manufacturing a long inorganic fiber sheet.

[0027] In the present invention, when the fiber diameter measured in the above measurement step deviates from a preset predetermined range, the result is fed back, and the production conditions of the inorganic fiber precursor sheet and / or the firing conditions in the above firing step are controlled so that the fiber diameter falls within the above predetermined range. It is possible to confirm online the variation in the fiber diameter of the inorganic fiber and its deviation from the allowable range, and by feeding back the result and controlling the production conditions of the inorganic fiber precursor sheet and / or the firing conditions in the firing step, the fiber diameter of the inorganic fiber can be kept within the allowable range.

[0028] In the present invention, it is preferable that the inorganic fiber sheet used in the above sample collection step is an inorganic fiber sheet subjected to needling treatment. This is because the present invention is useful for an inorganic fiber sheet subjected to needling treatment.

Advantages of the Invention

[0029] In the present invention, it is possible to guarantee the continuity and uniformity of the fiber diameter of the inorganic fibers in the inorganic fiber sheet, and also to guarantee the continuous safety of the fiber diameter of the inorganic fibers in the inorganic fiber sheet. Furthermore, it has the effect that the fiber diameter of the inorganic fibers in the inorganic fiber sheet can be measured not only after the production of the inorganic fiber sheet but also during the production of the inorganic fiber sheet.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0031] Hereinafter, the fiber diameter measuring device, the inorganic fiber sheet manufacturing device, the fiber diameter measuring method, and the inorganic fiber sheet manufacturing method of the present invention will be described.

[0032] A. Fiber diameter measuring device First, the fiber diameter measuring device of the present invention will be described. The fiber diameter measuring device of the present invention is a fiber diameter measuring device for measuring the fiber diameter of the inorganic fiber in an inorganic fiber sheet containing inorganic fibers, and is characterized in that it includes a sample collection means capable of collecting a predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet, and a measurement means for measuring the fiber diameter of the collected inorganic fibers.

[0033] Here, the "entire area of the inorganic fiber sheet" refers to the minimum area necessary for collecting a fiber diameter measurement sample representing the entire inorganic fiber sheet, means the entire in-plane direction of the inorganic fiber sheet, and preferably the entire in-plane direction and thickness direction of the inorganic fiber sheet.

[0034] In the present invention, as will be described later, a fiber diameter measurement sample representing the entire inorganic fiber sheet is collected by sampling from one side or both sides of the inorganic fiber sheet by the sample collection means. Whether the collection of the inorganic fibers by the sample collection means is from one side of the inorganic fiber sheet or from both sides of the inorganic fiber sheet can be appropriately selected according to the manufacturing method of the inorganic fiber sheet, particularly the manufacturing method of the inorganic fiber precursor sheet used in the manufacture of the inorganic fiber sheet.

[0035] Specifically, the inorganic fiber precursor that forms the inorganic fiber precursor sheet is formed through a spinning process such as the blowing method or the spinning method. In the case of a manufacturing method in which each inorganic fiber precursor is present in a so-called random manner in the thickness direction when forming the inorganic fiber precursor sheet, even if the sample collection means is arranged only on one side of the inorganic fiber sheet, it can be said that inorganic fibers representing the entire area of the inorganic fiber sheet can be sufficiently obtained. Therefore, it is also possible to arrange the sample collection means only on one side of the inorganic fiber sheet. Note that the so-called random presence of the spun inorganic fiber precursor in the thickness direction of the inorganic fiber precursor sheet means that the inorganic fiber precursor discharged from a certain spinning nozzle in the above spinning process does not always exist at a fixed position in the inorganic fiber precursor sheet, but exists with an equal probability density in any location in the in-plane direction or the thickness direction of the inorganic fiber precursor sheet.

[0036] In addition, when the inorganic fiber precursors are dispersed with equal probability in the thickness direction of the inorganic fiber precursor sheet but are not dispersed with equal probability in the in-plane direction of the inorganic fiber precursor sheet, although it cannot be said to be so-called random, by collecting inorganic fibers throughout the in-plane direction of the inorganic fiber sheet using the sample collection means, even when the sample collection means is arranged only on one side of the inorganic fiber sheet, it can be said that a fiber diameter measurement sample representing the entire inorganic fiber sheet can be collected. Therefore, an aspect of arranging the sample collection means only on one side of the inorganic fiber sheet can also be adopted.

[0037] Examples of the manufacturing method in which the spun inorganic fiber precursor is present in a so-called random manner in the thickness direction of the inorganic fiber precursor sheet include a manufacturing method in which a sheet shape is formed after stacking by folding ninety-nine times, and a manufacturing method in which the inorganic fiber precursors are mixed and then stacked to form a sheet shape so as to be completely random.

[0038] Among them, in the aspect where the sample collection means is actually arranged only on one side of the inorganic fiber sheet, when the measurement result of the fiber diameter indicating that the collected inorganic fibers represent the inorganic fiber sheet is shown, it is preferable to adopt the aspect of arranging the sample collection means only on one side of the inorganic fiber sheet.

[0039] In this case, the representative means that, as also described in the evaluation of the following Examples and Reference Examples, in the mode where the sample collection means is arranged only on one side of the inorganic fiber sheet, the collected inorganic fibers (hereinafter sometimes described as collected method fibers) are made or adjusted by the conventional punching method (preferably in accordance with Commission Regulation (EC) No 761 / 2009 of 23 July 2009) from the inorganic fiber sheet or the measurement sample (hereinafter sometimes described as conventional method fibers). When compared, it means that the average fiber diameter of the collected method fibers is within the range of the variation of the conventional method fibers (as in the following Reference Examples, after dividing the inorganic fiber sheet into a certain area, the sample is made or adjusted, and it may also be the variation of the average fiber diameter of each divided inorganic fiber sheet). This variation means that when the probability density distribution of the variation of the fiber diameter or average fiber diameter of the conventional method fibers is a normal distribution, if its standard deviation is σ (sigma), it is preferably within ±3σ of the average value, more preferably within ±2σ of the average value, and even more preferably within ±σ of the average value. Similarly, when the probability density distribution of the variation of the fiber diameter or average fiber diameter of the above conventional method fibers is not a normal distribution, the average fiber diameter of the collected method fibers is preferably within 49.85% on both the thicker side and the thinner side from the center (average value) of the existence establishment of the fiber diameter or average fiber diameter of the conventional method fibers, more preferably within 47.70%, and even more preferably within 34.15%.

[0040] On the one hand, when each inorganic fiber precursor forms an inorganic fiber precursor sheet, if the inorganic fiber precursors do not exist in a so-called random manner in the in-plane direction and the thickness direction of the inorganic fiber precursor sheet, and the inorganic fiber precursors discharged from a specific spinning nozzle exist at specific positions on the inorganic fiber precursor sheet with certainty or a high probability, it can be said that by arranging the sample collection means on both sides of the inorganic fiber sheet, inorganic fibers representative of the inorganic fiber sheet can be sufficiently obtained from the entire area of the inorganic fiber sheet. Therefore, it is preferable to arrange the sample collection means on both sides of the inorganic fiber sheet. In addition, when the inorganic fiber precursors are dispersed in the in-plane direction of the inorganic fiber precursor sheet with equal probability, but are not dispersed in the thickness direction of the inorganic fiber precursor sheet with equal probability, if the sample collection means is not particularly arranged on both sides of the inorganic fiber sheet, there may be a case where it cannot be said that a fiber diameter measurement sample representative of the entire inorganic fiber sheet has been collected. Therefore, it is preferable to arrange the sample collection means on both sides of the inorganic fiber sheet and collect inorganic fibers from both sides of the inorganic fiber sheet.

[0041] However, this is not the case when the thickness of the inorganic fiber sheet is extremely thin and inorganic fibers representative of the inorganic fiber sheet can be obtained without being affected by the bias of the probability density by passing through the pretreatment means for assisting the collection of inorganic fibers. Whether the thickness of the inorganic fiber sheet is extremely thin and inorganic fibers representative of the inorganic fiber sheet can be obtained without being affected by the bias of the probability density by the pretreatment means for assisting the collection of inorganic fibers refers to the case where, in the mode of arranging the sample collection means only on one side of the inorganic fiber sheet, the measured fiber diameter of the collected inorganic fibers shows a result indicating that they are representative of the inorganic fiber sheet. The measured fiber diameter result indicating that the inorganic fibers are representative of the inorganic fiber sheet is the same as the representative when determining whether the sample collection means can be arranged only on one side of the inorganic fiber sheet as described above, and the criterion is whether it is within the range of variation, and the details are as described above.

[0042] Also, for example, when trimming a predetermined area at the end in the width direction of the inorganic fiber sheet, the "entire area of the inorganic fiber sheet" also includes a mode in which it is the entire area of the inorganic fiber sheet after trimming.

[0043] The fiber diameter measuring apparatus of the present invention will be described with reference to the drawings. In this specification, in the description of the drawings, the same reference numerals are given to the same elements, and redundant descriptions may be omitted.

[0044] FIG. 1 is a schematic diagram showing an example of the fiber diameter measuring apparatus of the present invention. The fiber diameter measuring apparatus 10 shown in FIG. 1 is an example of a fiber diameter measuring apparatus that measures the fiber diameter of inorganic fibers in a long inorganic fiber sheet 1. As illustrated in FIG. 1, the fiber diameter measuring apparatus 10 includes a sample collection means 2 that can collect a predetermined amount of inorganic fibers over the entire area of the inorganic fiber sheet 1, and a measurement means 3 that measures the fiber diameter of the collected inorganic fibers. In the example shown in FIG. 1, the sample collection means 2 is disposed on the lower surface of the inorganic fiber sheet 1, but the arrangement of the sample collection means 2 is not limited to this, and it may be disposed on the upper surface of the inorganic fiber sheet 1.

[0045] In the fiber diameter measuring apparatus 10 shown in FIG. 1, the long inorganic fiber sheet 1 is conveyed by conveying rolls 11 and 12. First, when the sample collection means 2 collects inorganic fibers from the lower surface of the inorganic fiber sheet 1, it has a sample recovery means 2c such as a container with an open upper surface. At this time, the sample collection means 2 preferably has a sample moving means 2a for moving the inorganic fibers in order to increase the amount of inorganic fiber collection per unit time. Examples of the sample moving means 2a include a suction means and a physical conveyance means, as will be described later. Among them, the suction means is preferable as the sample moving means 2a because it is simple.

[0046] Hereinafter, in the fiber diameter measuring apparatus 10 shown in FIG. 1, the case where the sample collection means 2 has a suction means as the sample moving means 2a and a sample recovery means 2c will be described.

[0047] In this case, in the region where the suction port of the sample moving means 2a (suction means) contacts or is close to the inorganic fiber sheet 1, inorganic fibers serving as samples can be efficiently moved from the inorganic fiber sheet 1 to the sample collection means 2c. As a result, inorganic fibers can be efficiently collected. Therefore, for example, by setting the width of the suction port of the sample moving means 2a (suction means) to be equal to or greater than the width of the inorganic fiber sheet 1, or by moving the sample moving means 2a (suction means) relative to the inorganic fiber sheet 1, a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet 1.

[0048] Also, in the sample moving means 2a (suction means), inorganic fibers are collected by sucking the inorganic fibers from the inorganic fiber sheet 1. Since it is not necessary to punch out or cut out the inorganic fiber sheet 1 for sample collection, it is possible to suppress damage to the appearance of the inorganic fiber sheet 1. Next, for the collected inorganic fibers, the fiber diameter is measured by the measuring means 3. The measuring means 3 can measure the average fiber diameter, fiber diameter distribution, etc. of the inorganic fiber diameter. As the measuring means 3, it is preferable to use an automatic fiber diameter measuring device in terms of easily obtaining measurement results continuously.

[0049] Further, in the fiber diameter measuring device of the present invention, it is preferable that the sample collection means 2 has a pretreatment means for assisting in the collection of inorganic fibers serving as samples. Examples of the pretreatment means include physical non-contact means and physical contact means as described below. Examples of the physical non-contact means include, as described below, for example, supply means for supplying gas or liquid to the inorganic fiber sheet, and means for intermittently supplying air or the like to vibrate the inorganic fiber sheet itself. Examples of the physical contact means include, as described below, for example, means for bringing a plate-like object, a brush-like object, and a comb-like object into substantially horizontal contact with the surface of the inorganic fiber sheet, means for picking inorganic fibers from the inorganic fiber sheet with a picking tool, and means for vibrating the contact portion with the inorganic fiber sheet during conveyance. Among them, as the pretreatment means, as described below, supply means and vibration means are preferable.

[0050] Hereinafter, the case where the sample collection means includes a supply means as a pretreatment means, a sample recovery means, and a sample transfer means will be described with reference to FIG. 2. Further, the case where the sample collection means includes a vibration means as a pretreatment means and a sample recovery means will be described with reference to FIG. 3.

[0051] FIG. 2 is a schematic diagram showing another example of the fiber diameter measuring apparatus of the present invention. In the example shown in FIG. 2, the sample collection means 2 includes, as a pretreatment means, a supply means 2b for supplying a gas such as air or a liquid such as water to the inorganic fiber sheet 1 from the upper surface of the inorganic fiber sheet 1, and a sample transfer means 2a for transferring the inorganic fibers contained in the gas or liquid from the lower surface of the inorganic fiber sheet 1, and further includes a sample recovery means 2c. In the example shown in FIG. 2, the sample transfer means 2a and the sample recovery means 2c are arranged facing the supply means 2b, but the arrangement of the sample transfer means 2a and the sample recovery means 2c is not limited to this, and for example, they may be arranged immediately after the supply means 2b.

[0052] In the fiber diameter measuring apparatus 10 shown in FIG. 2, first, the supply means 2b supplies a gas or a liquid from the upper surface of the inorganic fiber sheet 1, passes the gas or the liquid in the thickness direction of the inorganic fiber sheet 1, and the sample transfer means 2a and the sample recovery means 2c recover the gas or the liquid containing the inorganic fibers from the lower surface of the inorganic fiber sheet 1, and as a result, the inorganic fibers are collected. At this time, in the region where the gas or the liquid is supplied to the inorganic fiber sheet 1, the inorganic fibers can be collected from the inorganic fiber sheet 1. Therefore, for example, by supplying a gas or a liquid to the entire width direction of the inorganic fiber sheet 1 by the supply means 2b, a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet 1. Further, in the supply means 2b, the sample transfer means 2a, and the sample recovery means 2c, the inorganic fibers are collected by passing a gas or a liquid in the thickness direction of the inorganic fiber sheet 1, and since it is not necessary to punch out or cut out the inorganic fiber sheet 1 for sample collection, it is possible to suppress damage to the appearance of the inorganic fiber sheet 1. Next, the fiber diameter of the collected inorganic fibers is measured by the measuring means 3.

[0053] FIG. 3 is a schematic diagram showing another example of the fiber diameter measuring apparatus of the present invention. In the example shown in FIG. 3, the sample collection means 2 has, as a pretreatment means, a vibration means 2d disposed on the lower surface of the inorganic fiber sheet 1 for applying vibration to the inorganic fiber sheet 1, and further has a sample recovery means 2c disposed on the lower surface of the inorganic fiber sheet 1 for collecting the inorganic fibers that have fallen due to vibration. In the example shown in FIG. 3, the vibration means 2d is disposed on the lower surface of the inorganic fiber sheet 1, but the arrangement of the vibration means 2d is not limited to this, and it may be disposed on the upper surface of the inorganic fiber sheet 1.

[0054] In the fiber diameter measuring apparatus 10 shown in FIG. 3, first, the vibration means 2d applies vibration to the inorganic fiber sheet 1, and the sample recovery means 2c acquires the inorganic fibers that have fallen due to vibration. At this time, in the region where the inorganic fiber sheet 1 is vibrated, inorganic fibers can be collected from the inorganic fiber sheet 1. Therefore, for example, by applying vibration to the entire width direction of the inorganic fiber sheet 1 by the vibration means 2d, a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet 1. Further, in the vibration means 2d and the sample recovery means 2c, inorganic fibers are collected by applying vibration to the inorganic fiber sheet 1, and there is no need to punch out or cut out the inorganic fiber sheet 1 for sample collection, so it is possible to suppress damage to the appearance of the inorganic fiber sheet 1. Next, the fiber diameter of the collected inorganic fibers is measured by the measuring means 3. Also in the fiber diameter measuring apparatus 10 shown in FIG. 3, the sample collection means 2 may have a sample moving means.

[0055] Note that FIGS. 1 to 3 are examples of a fiber diameter measuring apparatus for measuring the fiber diameter of inorganic fibers in a long inorganic fiber sheet, but the fiber diameter measuring apparatus of the present invention may be a fiber diameter measuring apparatus for measuring the fiber diameter of inorganic fibers in a single-sheet inorganic fiber sheet.

[0056] According to the present invention, in the sample collection means, since a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet, the collected inorganic fibers can be regarded as representative of the inorganic fibers in the inorganic fiber sheet. Therefore, by using the fiber diameter measuring device of the present invention, it is possible to guarantee the continuous safety of the fiber diameter of the inorganic fibers in the inorganic fiber sheet, and improve the accuracy of the measured average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers. For example, in the case of a long inorganic fiber sheet, it is possible to guarantee the average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers over the entire sheet area. Thus, it is possible to provide an inorganic fiber sheet with a higher level of safety.

[0057] Also according to the present invention, since the sample collection means is a means capable of collecting a predetermined amount of inorganic fibers over the entire area of the inorganic fiber sheet, it is possible to measure the fiber diameter of the inorganic fibers in the inorganic fiber sheet without punching or cutting out the inorganic fiber sheet for sample collection. Therefore, it is possible to measure the fiber diameter of the inorganic fibers in the inorganic fiber sheet not only after the production of the inorganic fiber sheet but also during the production of the inorganic fiber sheet. That is, it is possible to measure the fiber diameter of the inorganic fibers in the inorganic fiber sheet online. Therefore, it is possible to manage the average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers in the inorganic fiber sheet online. Also, it is possible to confirm the fluctuations and deviations from the allowable range of the average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers online, and by feeding back the results to the manufacturing process, etc. of the inorganic fiber sheet and controlling the manufacturing conditions, etc. of the inorganic fiber sheet, it is possible to keep the average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers within the allowable range.

[0058] According to the present invention, the sample collection means is a means capable of collecting a predetermined amount of inorganic fibers over the entire area of the inorganic fiber sheet, and since it does not punch out or cut out the inorganic fiber sheet, it is possible to suppress significant damage to the physical properties and appearance of the inorganic fiber sheet used for measurement. For example, when measuring the fiber diameter of inorganic fibers in an inorganic fiber sheet subjected to needling treatment, particularly in a needled inorganic fiber sheet, the warp yarns for binding short fibers in the thickness direction play an important role in ensuring physical properties and appearance. Therefore, it is important not to cause loss of warp yarns. By using the fiber diameter measuring device of the present invention, it is possible to obtain an inorganic fiber sheet with good physical properties and appearance even after fiber diameter measurement, and it can be used as a product as it is.

[0059] Hereinafter, the inorganic fiber sheet in the present invention and each component in the fiber diameter measuring device of the present invention will be described.

[0060] 1. Inorganic fiber sheet The inorganic fiber sheet in the present invention contains inorganic fibers. The inorganic fiber sheet is, for example, referred to as a mat or a blanket.

[0061] The inorganic fibers constituting the inorganic fiber sheet are not particularly limited. For example, one or more selected from alumina fibers, ceramic fibers, bio-dissolvable fibers (alkali earth silicate fibers), rock wool, basalt fibers, potassium titanate fibers, calcium silicate fibers, and glass fibers can be used. The inorganic fibers are preferably one or more selected from alumina fibers, ceramic fibers, bio-dissolvable fibers (alkali earth silicate fibers), and basalt fibers. Further, examples of the inorganic fibers include single or composite fibers such as silica, alumina / silica, zirconia, spinel, titania, and calcia containing these. Among them, alumina / silica fibers mainly composed of alumina and silica are preferred, and particularly, crystalline alumina / silica fibers are preferred. The ratio of aluminum and silicon is Al 2 O 3 / SiO 2When converted to a mass ratio, there is no particular limitation, but it is preferably in the range of 60:40 to 98:2, more preferably in the range of 65:35 to 95:5, and particularly preferably in the range of 70:30 to 80:20.

[0062] The inorganic fiber is preferably a short fiber. This is because it can enhance the toughness without impairing the thickness of the inorganic fiber sheet. Also, when the inorganic fiber is a short fiber, there is no problem with safety.

[0063] In addition, the fact that the inorganic fiber is a short fiber means, for example, that the average fiber length of the inorganic fiber is 1,000 mm or less. Also, when the inorganic fiber is a short fiber, the average fiber length of the inorganic fiber may be, for example, in the range of 210 μm or more and 1,000 μm or less.

[0064] The average fiber diameter of the inorganic fiber is not particularly limited, but it is preferably, for example, 3 μm or more and 15 μm or less, more preferably 4 μm or more and 13 μm or less, still more preferably 5 μm or more and 10 μm or less, and particularly preferably 5 μm or more and 8 μm or less. This is because the repulsive force and toughness of the inorganic fiber can be improved, and the strength of the fiber can be enhanced. In addition, if the average fiber diameter of the inorganic fiber is too large, the cold compression characteristics (cold compression) of the inorganic fiber sheet at room temperature will be lost. On the other hand, if the average fiber diameter is too small, there is a risk that more fibrous substances will reach the lungs when inhaled.

[0065] The inorganic fiber sheet is preferably subjected to needling treatment. As described above, particularly for an inorganic fiber sheet subjected to needling treatment, the warp yarns for binding the fibers in the thickness direction play an important role in ensuring the physical properties and appearance. Therefore, it is important not to damage the warp yarns. In the present invention, it is possible to suppress significant impairment of the physical properties and appearance of the inorganic fiber sheet used for measurement. Therefore, it is useful for measuring the fiber diameter of the inorganic fiber in the needled inorganic fiber sheet.

[0066] The needle-punched inorganic fiber sheet has a plurality of needle marks, that is, a plurality of recesses. The needle marks may be through-holes penetrating in the thickness direction of the inorganic fiber sheet, or may be non-through-holes that do not penetrate.

[0067] The number of needle marks per unit area of the inorganic fiber sheet (hereinafter referred to as the needle mark density) is not particularly limited. However, the larger the number, the higher the shearing force but the lower the surface pressure, and the smaller the number, the higher the surface pressure but the lower the shearing force. Therefore, it is preferable that the needle mark density is such that a good balance between the shearing force and the surface pressure can be achieved. As the needle mark density, for example, it can be 1.0 piece / cm 2 or more and 50.0 pieces / cm 2 or less.

[0068] Here, the number of needle marks can be the number of white dots projected onto the other surface when visible light is applied to one surface of the inorganic fiber sheet. Note that the above white dots can be confirmed whether the needle marks are through-holes or non-through-holes.

[0069] The needle marks may be provided at equal intervals in plan view, or may be provided randomly. As the average distance between two adjacent needle marks, for example, it can be 0.1 cm or more and 4 cm or less.

[0070] Also, the inorganic fiber sheet may be a hand-sheeted sheet.

[0071] The average thickness of the inorganic fiber sheet is not particularly limited and can be appropriately set according to the use and the like.

[0072] The inorganic fiber sheet may be in a long shape or in a single-sheet shape. Among them, a long inorganic fiber sheet is preferable. In the present invention, since the fiber diameter of the inorganic fibers in the inorganic fiber sheet can be measured online, it is useful in the case of a long inorganic fiber sheet.

[0073] The manufacturing method of the inorganic fiber sheet will be described in "D. Manufacturing Method of Inorganic Fiber Sheet" which will be described later, so the description here is omitted.

[0074] 2. Sample collection means The sample collection means in the present invention is a means capable of collecting a predetermined amount of the inorganic fiber over the entire area of the inorganic fiber sheet.

[0075] As the sample collection means, any means capable of collecting a predetermined amount of inorganic fiber over the entire area of the inorganic fiber sheet may be used. For example, it may be a means capable of collecting a predetermined amount of inorganic fiber over the entire in-plane direction of the inorganic fiber sheet, or it may be a means capable of collecting a predetermined amount of inorganic fiber over the entire in-plane direction and thickness direction of the inorganic fiber sheet. Among them, a means capable of collecting a predetermined amount of inorganic fiber representing the entire inorganic fiber sheet over the entire area of the inorganic fiber sheet is preferable, as it can improve the certainty of the fiber diameter.

[0076] Examples of the sample collection means include means capable of collecting a predetermined amount of inorganic fiber over the entire area of the inorganic fiber sheet without significantly impairing the physical properties and appearance of the inorganic fiber sheet. As described above, in the needled inorganic fiber sheet, since a good appearance is required, the sample collection means is preferably a means that does not significantly impair the appearance of the inorganic fiber sheet.

[0077] When collecting inorganic fiber from the inorganic fiber sheet by the sample collection means, it is sufficient to be able to collect a predetermined amount of inorganic fiber over the entire area of the inorganic fiber sheet. For example, inorganic fiber may be collected from one side of the inorganic fiber sheet, or inorganic fiber may be collected from both sides of the inorganic fiber sheet.

[0078] The collection of inorganic fiber may be performed continuously or intermittently. Among them, it is preferable to collect the inorganic fiber continuously, as it can improve the certainty of the fiber diameter.

[0079] Also, the sample collection means collects a predetermined amount of inorganic fibers over the entire area of the inorganic fiber sheet. At this time, the amount of inorganic fibers collected may be equal to or greater than the amount required for measuring the fiber diameter of the inorganic fibers. If an amount of inorganic fibers greater than the required amount is collected, it may be adjusted to the optimal amount required for measurement by methods such as quartering.

[0080] In addition, the inorganic fibers collected may include inorganic fibers that have naturally fallen from the inorganic fiber sheet.

[0081] (1) Sample recovery means The sample collection means in the present invention can have sample recovery means for recovering the above inorganic fibers. The sample recovery means is composed of, for example, an open container or the like. Specifically, as the sample recovery means, it may be arranged on the upper surface, lower surface or side surface of the inorganic fiber sheet, and a container with an upper surface and / or lower surface and / or side surface opening may be used as necessary using the sample transfer means described later.

[0082] The sample recovery means may be arranged on any of the upper surface, lower surface and side surface of the inorganic fiber sheet.

[0083] Also, the sample recovery means can be arranged so as to be in contact with or close to the surface of the upper surface or lower surface of the inorganic fiber sheet. Among them, when the sample transfer means described later is not used, it is preferable that the sample recovery means is arranged so as to be in contact with or close to the surface of the upper surface or lower surface of the inorganic fiber sheet. This is to prevent dust, floating fibers, etc. in the atmosphere from mixing into the inorganic fibers when collecting the inorganic fibers that have naturally fallen from the inorganic fiber sheet. In particular, when the sample transfer means is not used, it is preferable that the sample recovery means is arranged so as to be close to the surface of the upper surface or lower surface of the inorganic fiber sheet. This is because it is possible to suppress the appearance of the inorganic fiber sheet from being damaged when the sample recovery means comes into contact with the inorganic fiber sheet. In this case, it is preferable that the sample recovery means is arranged at a certain distance from the surface of the inorganic fiber sheet.

[0084] Also, as will be described later, the sample collection means in the present invention has a pretreatment means for assisting in the collection of the above inorganic fibers. When using a supply means for supplying a gas such as air or a liquid such as water to the inorganic fiber sheet as the pretreatment means, the supply means becomes a means for supplying a liquid or a gas from one or both sides of the inorganic fiber sheet, and the sample collection means is a means for collecting inorganic fibers or a gas or liquid containing inorganic fibers from the same side or the opposite side of the inorganic fiber sheet as the side where the supply means of the inorganic fiber sheet is arranged, or from both sides of the inorganic fiber sheet.

[0085] When the supply means is a gas supply means, the sample collection means may be any means capable of collecting inorganic fibers from the same side (for example, when the supply means is arranged on the upper surface of the inorganic fiber sheet, it indicates the upper surface of the inorganic fiber sheet) or the opposite side (for example, when the supply means is arranged on the upper surface of the inorganic fiber sheet, it indicates the lower surface of the inorganic fiber sheet) of the inorganic fiber sheet as the side where the supply means is arranged, or from both sides of the inorganic fiber sheet. For example, a container for receiving inorganic fibers can be used.

[0086] When the supply means is a liquid supply means, the sample collection means may be any means capable of collecting a liquid containing inorganic fibers from the same side (for example, when the supply means is arranged on the upper surface of the inorganic fiber sheet, it indicates the upper surface of the inorganic fiber sheet) or the opposite side (for example, when the supply means is arranged on the upper surface of the inorganic fiber sheet, it indicates the lower surface of the inorganic fiber sheet) of the inorganic fiber sheet as the side where the supply means is arranged, or from both sides of the inorganic fiber sheet. For example, a container for receiving a liquid containing inorganic fibers can be used.

[0087] Further, as will be described later, the sample collection means in the present invention has a pretreatment means. When using, as the pretreatment means, a means for bringing a plate-like object, a brush-like object, or a comb-like object (hereinafter sometimes referred to as a plate-like object or the like) into substantially horizontal contact with the surface of the inorganic fiber sheet, the sample collection means becomes a means for collecting the inorganic fibers generated by the contact of the plate-like object or the like with the inorganic fiber sheet. Among them, when the plate-like object or the like is disposed on the lower surface of the inorganic fiber sheet as the pretreatment means, the sample collection means may be a means for collecting the inorganic fibers that have fallen due to the contact of the plate-like object or the like with the inorganic fiber sheet.

[0088] When using, as the pretreatment means, a means for bringing a plate-like object or the like into substantially horizontal contact with the surface of the inorganic fiber sheet, the sample collection means may be any means that can collect the inorganic fibers generated or fallen due to the contact of the plate-like object or the like with the inorganic fiber sheet. For example, a container for receiving the inorganic fibers or the like is used. In this case, the sample collection means can be used together with the sample transfer means described later.

[0089] When using, as the pretreatment means, a means for bringing a plate-like object or the like into substantially horizontal contact with the surface of the inorganic fiber sheet, and when the plate-like object or the like is disposed on the lower surface of the inorganic fiber sheet, the sample collection means is usually disposed on the lower surface of the inorganic fiber sheet, but this is not the case when using the sample transfer means described later.

[0090] Further, as will be described later, the sample collection means in the present invention has a pretreatment means. When using, as the pretreatment means, a vibration means for applying vibration to the inorganic fiber sheet, the sample collection means may be any means that can collect the inorganic fibers that have fallen due to the vibration. For example, a container for receiving the inorganic fibers or the like is used.

[0091] When using the vibration means as the pretreatment means, the sample collection means is usually disposed on the lower surface of the inorganic fiber sheet, but this is not the case when using the sample transfer means described later.

[0092] (2) Sample transfer means The sample collection means in the present invention may be arranged on one or both sides of the inorganic fiber sheet and may have a sample moving means for moving the inorganic fibers. By having the sample moving means, the amount of inorganic fiber collected per unit time can be increased.

[0093] Examples of the sample moving means include a suction means; a means for moving the inorganic fibers near the surface of the inorganic fiber sheet by a conveying device such as a belt conveyor, and a physical conveying means such as a means for moving a pair of tweezers that have picked up the inorganic fibers, opening the pair of tweezers, and as a result, moving the inorganic fibers to the sample collection means.

[0094] The sample moving means may be arranged on one side of the inorganic fiber sheet or on both sides of the inorganic fiber sheet. Further, when the sample moving means is arranged on one side of the inorganic fiber sheet, it may be arranged on the upper surface of the inorganic fiber sheet or on the lower surface of the inorganic fiber sheet.

[0095] Further, the sample moving means can be arranged so as to be in contact with or close to one or both sides of the inorganic fiber sheet. Among these, it is preferable that the sample moving means is arranged so as to be close to one or both sides of the inorganic fiber sheet. This is because, when the sample moving means comes into contact with the inorganic fiber sheet, it is possible to suppress the appearance of the inorganic fiber sheet from being damaged. In this case, it is preferable that the sample moving means is arranged at a certain distance from one or both sides of the inorganic fiber sheet.

[0096] Further, as will be described later, when the sample collection means in the present invention has a pretreatment means and a supply means is used as the pretreatment means, in order to efficiently collect the inorganic fibers, it is preferable that the sample collection means has a sample moving means.

[0097] When the supply means is a gas supply means, the sample moving means may be any means for moving the inorganic fibers. For example, the above-described suction means or physical conveying means can be used.

[0098] When the supply means is a liquid supply means, the sample moving means may be any means for moving a liquid containing inorganic fibers. For example, the above-described suction means can be used.

[0099] Also, as will be described later, the sample collection means in the present invention has a pretreatment means. When using, as the pretreatment means, a means for bringing a plate-like object or the like into substantially horizontal contact with the surface of the inorganic fiber sheet, the sample collection means preferably has a sample moving means.

[0100] When using, as the pretreatment means, a means for bringing a plate-like object or the like into substantially horizontal contact with the surface of the inorganic fiber sheet, the sample moving means may be any means for moving inorganic fibers. For example, the above-described suction means and physical conveyance means can be used.

[0101] When using, as the pretreatment means, a means for bringing a plate-like object or the like into substantially horizontal contact with the surface of the inorganic fiber sheet, the sample moving means is usually arranged on the same surface as the surface on which the pretreatment means of the inorganic fiber sheet is arranged. Note that the arrangement of the sample moving means is as described above.

[0102] Also, as will be described later, the sample collection means in the present invention has a pretreatment means for assisting in the collection of the above-described inorganic fibers. When using a vibration means as the pretreatment means, in order to efficiently collect the inorganic fibers, the sample collection means preferably has a sample moving means.

[0103] When using a vibration means as the pretreatment means, the sample moving means may be any means for moving inorganic fibers. For example, the above-described suction means and physical conveyance means can be used.

[0104] When using a vibration means as the pretreatment means, the sample moving means is usually arranged only on the lower surface or both surfaces of the inorganic fiber sheet. This is because when using the vibration means, it is necessary to collect the inorganic fibers that have fallen from the inorganic fiber sheet. Note that the arrangement of the sample moving means is as described above.

[0105] (2-1) Suction means As the sample moving means, among others, suction means is preferable because it is simple.

[0106] The suction means is means for suctioning inorganic fibers, which is disposed on one side or both sides of the inorganic fiber sheet.

[0107] The suction means may be disposed on one side of the inorganic fiber sheet or on both sides of the inorganic fiber sheet. Also, when the suction means is disposed on one side of the inorganic fiber sheet, it may be disposed on the upper surface of the inorganic fiber sheet or on the lower surface of the inorganic fiber sheet. When the suction means is disposed on the lower surface of the inorganic fiber sheet, regardless of the thickness of the inorganic fiber sheet to be measured, the distance between the inorganic fiber sheet and the suction means can be set to a constant distance. On the other hand, when the suction means is disposed on the upper surface of the inorganic fiber sheet, it is possible to suppress the collection of dust and the like.

[0108] Also, the suction means is disposed so as to be in contact with or close to one side or both sides of the inorganic fiber sheet. In this case, it is preferable that the suction means is disposed at a certain distance from one side or both sides of the inorganic fiber sheet. This is because by maintaining a constant distance in the thickness direction, inorganic fibers can always be collected with a constant suction force. Also, in this case, the above-mentioned constant distance may be zero, that is, the suction means may be in contact with one side or both sides of the inorganic fiber sheet. Among others, it is preferable that the suction means is disposed so as to be close to one side or both sides of the inorganic fiber sheet. This is because when the suction means comes into contact with the inorganic fiber sheet, it is possible to suppress the appearance of the inorganic fiber sheet from being damaged, suppress the inorganic fiber sheet from curving in the suction direction and the physical properties and the like from being damaged, and reduce the possibility of foreign matter such as dust being mixed into the suction means.

[0109] The output of the suction means is not particularly limited as long as it can suction inorganic fibers without significantly damaging the appearance of the inorganic fiber sheet.

[0110] As for the size of the suction means, as long as a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet and the inorganic fibers can be suctioned without significantly damaging the appearance of the inorganic fiber sheet, it is not particularly limited. For example, the width of the suction port of the suction means may be equal to or greater than the width of the inorganic fiber sheet, or may be less than the width of the inorganic fiber sheet. Among these, it is preferable that the width of the suction port of the suction means is equal to or greater than the width of the inorganic fiber sheet. This is because inorganic fibers can be uniformly collected in the width direction of the inorganic fiber sheet. On the other hand, even when the width of the suction port of the suction means is less than the width of the inorganic fiber sheet, as will be described later, by moving the suction means relative to the inorganic fiber sheet, a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet. Also, when the width of the suction port of the suction means is small, the suction force can be increased, and the collection of dust and the like can be suppressed.

[0111] Here, when the width of the suction port of the suction means is equal to or greater than the width of the inorganic fiber sheet, for example, when trimming a predetermined region at the end in the width direction of the inorganic fiber sheet, a mode in which the width of the suction port of the suction means is equal to or greater than the width of the inorganic fiber sheet after trimming is also included.

[0112] Also, the suction means may be fixed at an arbitrary position, or may be arranged to be movable to an arbitrary position. When the suction means is arranged to be movable, the suction means may be movable in any of the width direction, longitudinal direction, and thickness direction of the inorganic fiber sheet. For example, when the suction means is movable in the width direction of the inorganic fiber sheet, inorganic fibers can be uniformly collected in the width direction of the inorganic fiber sheet. Specifically, the suction means may be reciprocated in the entire width direction of the inorganic fiber sheet. Also, for example, when the suction means is movable in the thickness direction of the inorganic fiber sheet, when the suction means is arranged on the upper surface of the inorganic fiber sheet, the distance between the inorganic fiber sheet and the suction means can be set to a constant distance according to the thickness of the inorganic fiber sheet to be measured.

[0113] Specifically, a dust collector can be used as the suction means.

[0114] The suction of the inorganic fibers may be performed continuously or intermittently. Among them, it is preferable to continuously perform the suction of the inorganic fibers because the certainty of the fiber diameter can be improved.

[0115] (3) Pretreatment means The sample collection means in the present invention may have a pretreatment means for assisting the collection of the inorganic fibers.

[0116] The pretreatment means is not particularly limited as long as it is a means for assisting the collection of inorganic fibers, but preferably, it is a means that does not significantly damage the physical properties and appearance of the inorganic fiber sheet. Specifically, a means with a low possibility of damaging the warp yarns for maintaining the restraint in the thickness direction generated in the needling process is preferable.

[0117] The pretreatment means is disposed on one or both sides of the inorganic fiber sheet, and is preferably disposed around the sample collection means. Further, for example, the pretreatment means may be disposed on one side of the inorganic fiber sheet, and the sample collection means may be disposed on the other side. Further, for example, the pretreatment means may be disposed on one side of the inorganic fiber sheet, and the sample collection means may be disposed on the same side. Further, for example, the pretreatment means may be disposed on both sides of the inorganic fiber sheet, and the sample collection means may be disposed on the same side thereof.

[0118] The pretreatment means is not particularly limited as long as it is a means for assisting the collection of inorganic fibers, and examples thereof include a physical non-contact means that is physically non-contact with the inorganic fiber sheet, and a physical contact means that is physically in contact with the inorganic fiber sheet. Further, the physical non-contact means and the physical contact means may be used in combination.

[0119] (3-1) Physical non-contact means As physical non-contact means, there are no particular restrictions as long as they are physically non-contact with the inorganic fiber sheet and assist in inorganic fiber collection. Among them, supply means for supplying gases such as air and liquids such as water to the inorganic fiber sheet, and means for intermittently supplying air or the like to vibrate the inorganic fiber sheet itself are preferable. The physical contact means may be each of the above means alone or a combination of the above means.

[0120] Note that the means for intermittently supplying air or the like to vibrate the inorganic fiber sheet itself is one of the vibration means described later. The vibration means will be described later.

[0121] (3-1-1) Supply means The supply means is means for supplying gases such as air and liquids such as water to the inorganic fiber sheet from one side or both sides of the inorganic fiber sheet.

[0122] As the gas, for example, air, steam, carbon dioxide, nitrogen, etc. can be used. Among them, air is preferable in terms of being a gas at normal temperature and pressure and safety. The gas may be used alone or in a mixture of two or more.

[0123] Also, the boiling point of the liquid is preferably 120°C or lower, and more preferably in the range of 60°C to 110°C. This is because when the boiling point of the liquid is within the above range, the liquid can be easily removed. On the other hand, if the boiling point is too high, it becomes difficult to completely remove the liquid. Also, if the boiling point is too low, the evaporation rate of the liquid becomes high, and it becomes difficult to sufficiently penetrate the liquid into the inorganic fiber sheet. As a result, it may become difficult to recover the liquid containing the inorganic fiber.

[0124] The vapor pressure of the liquid at room temperature (25°C) is preferably relatively low, specifically preferably 5 kPa or lower. If the vapor pressure is too high, the evaporation rate of the liquid becomes high, and it becomes difficult to sufficiently penetrate the liquid into the inorganic fiber sheet. As a result, it may become difficult to recover the liquid containing the inorganic fiber.

[0125] The viscosity of the liquid is preferably relatively low, specifically preferably 3.5 mPa·s or less. If the viscosity of the liquid is low, the liquid is likely to impregnate the inorganic fiber sheet, making it easier to recover the liquid containing the inorganic fiber. On the other hand, if the viscosity of the liquid is too high, it becomes difficult to sufficiently penetrate the liquid into the inorganic fiber sheet, and as a result, it may become difficult to recover the liquid containing the inorganic fiber.

[0126] Here, the viscosity refers to the viscosity at 20°C and is a value measured using a rotational viscometer in accordance with JIS Z8803 (Method for Measuring Viscosity of Liquids).

[0127] The liquid is not particularly limited as long as it can penetrate the inorganic fiber sheet, but it is preferably one that satisfies the above boiling point and viscosity. Examples of such liquids include water and lower alcohols such as ethanol. Among them, water is preferred. Water is also suitable from an environmental perspective. For example, pure water can be used as the water. The liquid may be used alone or in combination of two or more.

[0128] The gas supply means is not particularly limited as long as it can uniformly supply gas to the inorganic fiber sheet without significantly damaging the appearance of the inorganic fiber sheet. Examples include means for spraying gas onto the inorganic fiber sheet. Also, the gas supply may be continuous or intermittent. Among them, it is preferable to supply the gas continuously because it can improve the certainty of the fiber diameter.

[0129] The liquid supply means is not particularly limited as long as it can uniformly supply the liquid to the inorganic fiber sheet without significantly damaging the appearance of the inorganic fiber sheet. For example, means for applying or spraying the liquid onto the inorganic fiber sheet can be mentioned. Among them, it is preferable that the liquid supply means is a non-contact method. This is because it can suppress the damage to the appearance of the inorganic fiber sheet. Also, the liquid supply may be performed continuously or intermittently. Among them, it is preferable that the liquid supply is performed continuously. This is because the certainty of the fiber diameter can be improved.

[0130] As the gas or liquid supply means, as long as the appearance of the inorganic fiber sheet is not significantly damaged, a fluid jet device that blows a fluid such as a gas such as steam or a liquid such as water may be used. Examples of the fluid jet device include a steam jet device, a water jet device, etc. When the supply means is a fluid jet device, it can also serve as the needling means for performing needling treatment on the inorganic fiber precursor sheet and the inorganic fiber sheet described later.

[0131] The supply amount and pressure of the gas are not particularly limited as long as the gas can be uniformly supplied to the inorganic fiber sheet without significantly damaging the appearance of the inorganic fiber sheet and the inorganic fibers can be recovered by the above sample recovery means, and are appropriately selected according to the thickness of the inorganic fiber sheet, etc.

[0132] The supply amount and pressure of the liquid are not particularly limited as long as the liquid can be uniformly supplied to the inorganic fiber sheet without significantly damaging the appearance of the inorganic fiber sheet and the liquid containing the inorganic fibers can be recovered by the above sample recovery means, and are appropriately selected according to the thickness of the inorganic fiber sheet, etc.

[0133] (3-2) Physical contact means As physical contact means, there are no particular restrictions as long as the means physically contacts the inorganic fiber sheet and assists in inorganic fiber collection. For example, plate-shaped objects such as spatulas made of metal, resin, ceramic, or rubber, brush-shaped objects such as brushes, and comb-shaped objects such as combs are brought into substantially horizontal contact with the surface of the inorganic fiber sheet; means of picking inorganic fibers from the inorganic fiber sheet with picking tools such as tweezers; and means of vibrating the contact part with the inorganic fiber sheet during conveyance, etc. can be mentioned. The physical non-contact means may be each of the above means alone or a combination of the above means.

[0134] Among them, as physical contact means, means of bringing plate-shaped objects such as spatulas, brush-shaped objects such as brushes, and comb-shaped objects such as combs into substantially horizontal contact with the surface of the inorganic fiber sheet, and means of vibrating the contact part with the inorganic fiber sheet during conveyance are preferable.

[0135] Note that the means of vibrating the contact part with the inorganic fiber sheet during conveyance is one of the vibration means described later. The vibration means will be described later.

[0136] (3-2-1) Means of bringing a plate-shaped object, etc. into substantially horizontal contact with the surface of the inorganic fiber sheet Plate-shaped objects such as spatulas, brush-shaped objects such as brushes, and comb-shaped objects such as combs (hereinafter sometimes referred to as plate-shaped objects, etc.) scrape together the surface of the inorganic fiber sheet and the inorganic fibers near the surface by bringing them into substantially horizontal contact with the surface of the inorganic fiber sheet.

[0137] The plate-shaped objects, etc. are not particularly limited as long as they can collect inorganic fibers by contacting the surface of the inorganic fiber sheet. For example, plate-shaped objects such as spatulas, brush-shaped objects such as brushes, and comb-shaped objects such as combs can be used.

[0138] Examples of the material of the plate-shaped objects, etc. include metal, resin, ceramic, and rubber.

[0139] When collecting inorganic fibers using a plate-like object or the like, it is preferable to bring the plate-like object or the like into contact with the inorganic fiber sheet substantially horizontally so as not to damage the appearance of the inorganic fiber sheet.

[0140] The plate-like object or the like can be disposed on the lower surface or the upper surface of the inorganic fiber sheet, and on both of these surfaces.

[0141] (3-3) Vibration means As the pretreatment means, vibration means may be used as a physical non-contact means, or vibration means may be used as a physical contact means.

[0142] The vibration means is a means for applying vibration to the inorganic fiber sheet. The vibration means is preferable in that it can move the inorganic fibers inside the inorganic fiber sheet to the surface or near the surface of the inorganic fiber sheet. In addition, the vibration means can be expected to have the effect of moving the short fibers in the inorganic fiber sheet to the surface or near the surface of the inorganic fiber sheet so as to facilitate collection.

[0143] The vibration means is not particularly limited as long as it can apply vibration to the inorganic fiber sheet without significantly damaging the appearance of the inorganic fiber sheet. For example, means for intermittently supplying air or the like to vibrate the inorganic fiber sheet itself, and means for vibrating the contact portion with the inorganic fiber sheet during conveyance can be mentioned. As described above, the means for intermittently supplying air or the like to vibrate the inorganic fiber sheet itself is included in the physical non-contact means, and the means for vibrating the contact portion with the inorganic fiber sheet during conveyance is included in the physical contact means.

[0144] Examples of the means for intermittently supplying air or the like to vibrate the inorganic fiber sheet itself include a vibration generating means for generating vibration, and a blowing means for blowing air to the inorganic fiber sheet. Specific examples of the vibration generating means include ultrasonic vibration means, a motor, and the like.

[0145] As means for vibrating the contact portion with the inorganic fiber sheet during conveyance, for example, conveyance devices such as conveyance rolls or conveyance conveyors that convey the inorganic fiber sheet, or vibration means for vibrating the contact portion with the inorganic fiber sheet such as a substrate that supports the inorganic fiber sheet, and means for vibrating the inorganic fiber sheet by bringing a member separate from the conveyance device into contact with the inorganic fiber sheet can be mentioned. As the vibration means, specifically, ultrasonic vibration means, a motor, etc. can be used. Further, as the above-mentioned separate member, for example, a rod, a flapper, etc. can be used.

[0146] Also, the application of vibration may be performed continuously or intermittently. Among these, it is preferable to perform the application of vibration continuously. This is because the certainty of the fiber diameter can be improved.

[0147] The magnitude and frequency of the vibration are not particularly limited as long as the appearance of the inorganic fiber sheet is not significantly damaged, the inorganic fiber sheet can be vibrated, and the inorganic fibers can be collected by the vibration, and are appropriately selected.

[0148] The vibration means can be arranged on one side or both sides of the inorganic fiber sheet. When using the vibration means as the pretreatment means, since it is conceivable that the inorganic fibers may fall from the surface of the inorganic fiber sheet due to the vibration by the vibration means, it is preferable to arrange the vibration means near or at the same position as the sample collection means, but this is not the case when using the above-mentioned sample transfer means.

[0149] When the vibration means is a vibration generating means, the vibration generating means may be arranged on either the upper surface or the lower surface of the inorganic fiber sheet.

[0150] Also, when the vibration means is a blowing means, the blowing means may be arranged on any of the upper surface, lower surface, and side surface of the inorganic fiber sheet. Among these, it is preferable that the blowing means is arranged on the upper surface of the inorganic fiber sheet, and in this case, it can also serve as the above-mentioned supply means.

[0151] (3-4) Preferred embodiments of the pretreatment means As the above pretreatment means, the above supply means and vibration means are particularly preferable. This is because inorganic fibers can be collected without significantly damaging the appearance of the inorganic fiber sheet. Further, when the sample collection means has the supply means or the vibration means as the pretreatment means, the sample collection means can be configured to collect a predetermined amount of inorganic fibers over the entire in-plane direction and thickness direction of the inorganic fiber sheet. In this case, the accuracy of the fiber diameter can be improved.

[0152] (4) Image acquisition means The sample collection means in the present invention may have an image acquisition means for acquiring an image of the inorganic fibers collected from the inorganic fiber sheet. As the image acquisition means, means for acquiring a general image can be applied, and examples thereof include cameras such as CCD cameras and CMOS cameras. In the image acquisition means, for example, an image of the inorganic fibers collected by the above sample recovery means may be acquired, or an image of the inorganic fibers may be acquired without passing through the above sample recovery means. Therefore, when the sample collection means has the image acquisition means, the sample recovery means may or may not be provided. Further, when the sample collection means has the image acquisition means, the measurement means described below can be configured to perform measurement by image analysis.

[0153] (5) Preferred embodiments of the sample collection means As the above sample collection means, the above sample movement means or pretreatment means may be used alone, or the above sample movement means and pretreatment means may be used in combination. Further, the sample movement means may be each of the above means alone or a combination of the above means. Similarly, the pretreatment means may be each of the above means alone or a combination of the above means.

[0154] Among these, the sample collection means preferably has sample transfer means and / or pretreatment means. In particular, it preferably has suction means as the sample transfer means and / or supply means or vibration means as the pretreatment means. This is because with these sample collection means, inorganic fibers can be collected without significantly damaging the appearance of the inorganic fiber sheet.

[0155] 3. Measuring means The measuring means in the present invention is a means for measuring the fiber diameter of the collected inorganic fibers.

[0156] The measuring means is not particularly limited as long as it can measure the fiber diameter of inorganic fibers. For example, it may be an automatic fiber diameter measuring device or a manual fiber diameter measuring device. Using an automatic fiber diameter measuring device as the measuring means is preferable in that it is easy to continuously obtain measurement results.

[0157] Also, as the measuring means, means for measuring the fiber diameter of general inorganic fibers can be applied. For example, means for measuring by an optical microscope, a scanning electron microscope, means for measuring by image analysis, means for measuring by laser diffraction, etc. can be used. In addition, depending on the measuring means, means for processing the inorganic fibers to be measured into a form suitable for measurement may be provided. Examples of such means include means for dispersing the inorganic fibers in a solvent such as water and means for pulverizing the inorganic fibers. Specifically, there is a processing method in accordance with EU Regulation COMMISSION REGULATION (EC) No 761 / 2009.

[0158] The measurement of the fiber diameter of inorganic fibers may be performed continuously or intermittently.

[0159] After measuring the fiber diameter of the inorganic fibers by the measuring means, it is confirmed whether the fiber diameter of the inorganic fibers is within a predetermined range set in advance.

[0160] 4. Other embodiments of the fiber diameter measuring device Another embodiment of the fiber diameter measuring apparatus of the present invention is a fiber diameter measuring apparatus that measures the fiber diameter of the inorganic fibers in an inorganic fiber sheet containing inorganic fibers and subjected to needling treatment, and includes a sample collection means capable of collecting a predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet, and a measurement means for measuring the fiber diameter of the collected inorganic fibers, wherein the sample collection means has at least a sample recovery means for recovering the inorganic fibers.

[0161] B. Manufacturing Apparatus for Inorganic Fiber Sheet Next, the manufacturing apparatus for the inorganic fiber sheet of the present invention will be described. The manufacturing apparatus for the inorganic fiber sheet of the present invention is an apparatus including the above-described fiber diameter measuring apparatus.

[0162] FIG. 4 is a schematic diagram showing an example of the manufacturing apparatus for the inorganic fiber sheet of the present invention. The manufacturing apparatus 20 for the inorganic fiber sheet shown in FIG. 4 is an example of a manufacturing apparatus for manufacturing a long inorganic fiber sheet 1. As illustrated in FIG. 4, the manufacturing apparatus 20 for the inorganic fiber sheet includes a fiber diameter measuring apparatus 10 having a sample collection means 2 and a measurement means 3. The fiber diameter measuring apparatus 10 is the same as the fiber diameter measuring apparatus 10 shown in FIG. 1 described above. Further, the manufacturing apparatus 20 for the inorganic fiber sheet further includes a firing means 4 for continuously firing an inorganic fiber precursor sheet 1a containing an inorganic fiber precursor on the upstream side of the fiber diameter measuring apparatus 10.

[0163] In the manufacturing apparatus 20 for the inorganic fiber sheet shown in FIG. 4, the long inorganic fiber precursor sheet 1a and the long inorganic fiber sheet 1 are conveyed by conveying rolls 13, 11, and 12. First, the inorganic fiber precursor sheet 1a is continuously fired by the firing means 4 to obtain the inorganic fiber sheet 1. Next, in the fiber diameter measuring apparatus 10 having the sample collection means 2 and the measurement means 3, a predetermined amount of inorganic fibers is collected over the entire area of the inorganic fiber sheet 1, and the fiber diameter of the collected inorganic fibers is measured.

[0164] Note that FIG. 4 is an example of a manufacturing apparatus for measuring the fiber diameter of inorganic fibers in the long inorganic fiber sheet 1. However, the manufacturing apparatus for the inorganic fiber sheet of the present invention may include, for example, a cutting means for cutting the inorganic fiber sheet between the firing means and the fiber diameter measuring device (not shown), and may be a manufacturing apparatus for measuring the fiber diameter of inorganic fibers in a single-sheet inorganic fiber sheet.

[0165] According to the present invention, by providing the above-described fiber diameter measuring device, it is possible to guarantee the continuous safety of the fiber diameter of inorganic fibers in the inorganic fiber sheet, and to improve the certainty of the measured average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers. Specifically, it is possible to guarantee the average fiber diameter, fiber diameter distribution, etc. of inorganic fibers over the entire area of the long inorganic fiber sheet. Therefore, it is possible to provide an inorganic fiber sheet that pursues higher safety.

[0166] Also according to the present invention, by providing the above-described fiber diameter measuring device, it is possible to measure the fiber diameter of inorganic fibers in the inorganic fiber sheet not only after the production of the inorganic fiber sheet but also during the production of the inorganic fiber sheet. That is, it is possible to measure the fiber diameter of inorganic fibers in the inorganic fiber sheet online. Therefore, it is possible to manage the average fiber diameter, fiber diameter distribution, etc. of inorganic fibers in the inorganic fiber sheet online. In addition, it is possible to confirm fluctuations in the average fiber diameter, fiber diameter distribution, etc. of inorganic fibers and deviations from the allowable range online, and feedback the results to the manufacturing process, etc. of the inorganic fiber sheet, and control the manufacturing conditions, etc. of the inorganic fiber sheet to keep the average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers within the allowable range.

[0167] Also according to the present invention, by providing the above-described fiber diameter measuring device, it is possible to obtain an inorganic fiber sheet with a good appearance even after the fiber diameter measurement.

[0168] Hereinafter, each configuration in the manufacturing apparatus for the inorganic fiber sheet of the present invention will be described.

[0169] 1. Fiber diameter measuring device Since the fiber diameter measuring device in the present invention has been described in detail in the above "A. Fiber diameter measuring device", the description here is omitted.

[0170] 2. Inorganic fiber sheet manufacturing means The manufacturing apparatus of the inorganic fiber sheet of the present invention can be provided with inorganic fiber sheet manufacturing means for manufacturing an inorganic fiber sheet on the upstream side of the above fiber diameter measuring device.

[0171] The above inorganic fiber sheet manufacturing means is not particularly limited as long as it can manufacture an inorganic fiber sheet.

[0172] The above inorganic fiber sheet manufacturing means can have, for example, means for continuously manufacturing a long inorganic fiber sheet. Among them, it is preferable that the above inorganic fiber sheet manufacturing means has firing means for continuously firing an inorganic fiber precursor sheet containing an inorganic fiber precursor. This is because when continuously manufacturing an inorganic fiber sheet, the fiber diameter distribution is likely to fluctuate, and it becomes particularly difficult to obtain a fiber diameter measurement sample representing the inorganic fiber sheet.

[0173] Examples of the above inorganic fiber sheet manufacturing means include a first aspect having firing means for firing an inorganic fiber precursor sheet containing an inorganic fiber precursor, and a second aspect having papermaking sheet manufacturing means for manufacturing an inorganic fiber sheet that is a papermaking sheet. Each aspect will be described below.

[0174] (1) First aspect of inorganic fiber sheet manufacturing means The first aspect of the inorganic fiber sheet manufacturing means has firing means for firing an inorganic fiber precursor sheet containing an inorganic fiber precursor.

[0175] (1-1) Firing means The manufacturing apparatus of the inorganic fiber sheet of the present invention can be provided with firing means for firing an inorganic fiber precursor sheet containing an inorganic fiber precursor on the upstream side of the fiber diameter measuring apparatus. Among others, it is preferable that the manufacturing apparatus of the inorganic fiber sheet of the present invention is provided with firing means for continuously firing an inorganic fiber precursor sheet containing an inorganic fiber precursor on the upstream side of the fiber diameter measuring apparatus. This is because the present invention is useful for manufacturing a long inorganic fiber sheet.

[0176] Here, continuously firing the inorganic fiber precursor sheet means firing while conveying a long inorganic fiber precursor sheet.

[0177] The firing means is not particularly limited as long as it can continuously fire the inorganic fiber precursor sheet, and for example, a heating furnace or the like can be used.

[0178] The firing temperature of the inorganic fiber precursor sheet can be, for example, 500°C or higher, preferably in the range of 1000°C or higher and 1300°C or lower.

[0179] (1-2) Other means The first aspect of the inorganic fiber sheet manufacturing means may be provided with other means as necessary in addition to the above-described firing means.

[0180] The manufacturing apparatus of the inorganic fiber sheet of the present invention may be provided with needling means for subjecting the inorganic fiber precursor sheet to a needling treatment, for example, on the upstream side or the downstream side of the firing means. That is, the inorganic fiber precursor sheet may be subjected to a needling treatment. Among others, when the inorganic fiber sheet manufacturing means of this aspect is provided with needling means, it is preferable to provide the needling means on the upstream side of the firing means. The present invention is useful for an inorganic fiber sheet obtained by firing an inorganic fiber precursor sheet subjected to a needling treatment.

[0181] Furthermore, the manufacturing apparatus for the inorganic fiber sheet of the present invention may include, for example, upstream of the firing means and the needling means, in order from the upstream side, a spinning means for spinning a spinning solution to form an inorganic fiber precursor, and an inorganic fiber precursor sheet forming means for accumulating the inorganic fiber precursors to form an inorganic fiber precursor sheet. In the spinning means, a short fiber-like inorganic fiber precursor can be obtained.

[0182] Here, in the case of long fibers, fiber diameter control is easy at the spinning stage, and fiber length control is easy at the cutting or pulverizing stage, so safety is easy to ensure. On the other hand, in the case of short fibers, fiber diameter control is difficult compared to long fibers.

[0183] In the first aspect of the inorganic fiber sheet manufacturing means, since a short fiber-like inorganic fiber precursor is obtained in the spinning means as described above, the inorganic fiber sheet obtained in the first aspect of the inorganic fiber sheet manufacturing means is difficult to obtain a safety confirmation without inspection and is useful for the present invention.

[0184] (1-3) Inorganic fiber precursor sheet The inorganic fiber precursor sheet used in this aspect contains inorganic fiber precursors. As described above, the inorganic fiber precursor is preferably spun as short fibers.

[0185] The inorganic fiber precursor sheet may be in a long shape or a single leaf shape. Among them, the inorganic fiber precursor sheet is preferably in a long shape. This is because the present invention is suitable for a long inorganic fiber sheet.

[0186] When the inorganic fiber precursor sheet is subjected to needling treatment, it has a plurality of needle marks, that is, a plurality of recesses. The needle marks may be through holes penetrating in the thickness direction of the inorganic fiber precursor sheet or non-through holes that do not penetrate.

[0187] Note that the number of needle marks on the inorganic fiber precursor sheet can be the same as the number of needle marks on the above-described inorganic fiber sheet.

[0188] The average thickness of the inorganic fiber precursor sheet is not particularly limited and can be appropriately set according to the intended use and the like.

[0189] Note that the method for manufacturing the inorganic fiber precursor sheet will be described in "C. Method for Manufacturing Inorganic Fiber Sheet" which will be described later, so the description here is omitted.

[0190] (2) Second Aspect of Inorganic Fiber Sheet Manufacturing Means The manufacturing apparatus of the inorganic fiber sheet of the present invention may be provided with a sheet-making means for manufacturing an inorganic fiber sheet which is a sheet-making sheet on the upstream side of the fiber diameter measuring apparatus.

[0191] The sheet-making means may have, for example, a sheet-making means for sheet-making a slurry containing inorganic fibers, water, and a binder, and a drying means for drying the sheet obtained by the sheet-making means.

[0192] Note that the method for manufacturing the inorganic fiber sheet which is a sheet-making sheet will be described in "C. Method for Manufacturing Inorganic Fiber Sheet" which will be described later, so the description here is omitted.

[0193] The inorganic fiber sheet manufacturing means of this aspect may be provided with needling means for subjecting the inorganic fiber sheet to a needling treatment on the upstream side of the above-described sheet-making means, if necessary.

[0194] (3) Other Aspects of Inorganic Fiber Sheet Manufacturing Means The manufacturing apparatus of the inorganic fiber sheet of the present invention may be provided with means for manufacturing an inorganic fiber sheet and needling means for subjecting the inorganic fiber sheet to a needling treatment on the upstream side of the fiber diameter measuring apparatus. That is, the inorganic fiber sheet manufacturing means can be provided with needling means regardless of what means the means for manufacturing the inorganic fiber sheet is. The present invention is useful for an inorganic fiber sheet subjected to a needling treatment.

[0195] 3. Other Means In addition to the above-described fiber diameter measuring device, the manufacturing apparatus for the inorganic fiber sheet of the present invention may be provided with other means as necessary.

[0196] The manufacturing apparatus for the inorganic fiber sheet of the present invention may, for example, be provided with winding means for winding a long inorganic fiber sheet in a roll shape on the downstream side of the fiber diameter measuring device. Alternatively, the manufacturing apparatus for the inorganic fiber sheet of the present invention may, for example, be provided with cutting means for cutting the inorganic fiber sheet between the firing means and the fiber diameter measuring device.

[0197] The manufacturing apparatus for the inorganic fiber sheet of the present invention may, for example, be provided with impregnating means for impregnating a binder liquid into the inorganic fiber sheet and drying means for drying the binder liquid-impregnated inorganic fiber sheet obtained by impregnating the inorganic fiber sheet with the binder liquid on the downstream side of the fiber diameter measuring device.

[0198] C. Fiber Diameter Measuring Method Next, the fiber diameter measuring method of the present invention will be described. The fiber diameter measuring method of the present invention is a fiber diameter measuring method for measuring the fiber diameter of the inorganic fiber in an inorganic fiber sheet containing the inorganic fiber, and is characterized by having a sample collection step of collecting a predetermined amount of the inorganic fiber from the inorganic fiber sheet by a collection method capable of collecting the inorganic fiber over the entire area of the inorganic fiber sheet, and a measurement step of measuring the fiber diameter of the collected inorganic fiber.

[0199] According to the present invention, in the sample collection step, since a predetermined amount of inorganic fiber can be collected over the entire area of the inorganic fiber sheet, the accuracy of the measured fiber diameter of the inorganic fiber can be improved. Further, since the inorganic fiber sheet is not punched or cut out for sample collection, the fiber diameter of the inorganic fiber in the inorganic fiber sheet can be measured online. Furthermore, the appearance of the inorganic fiber sheet can be suppressed from being damaged by the measurement of the fiber diameter, and it can be used as a product even after the measurement of the fiber diameter.

[0200] Hereinafter, each step in the fiber diameter measuring method of the present invention will be described.

[0201] 1. Sample collection step In the sample collection step of the present invention, the inorganic fibers are collected from the inorganic fiber sheet by a collection method capable of collecting a predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet.

[0202] The method for collecting inorganic fibers is not particularly limited as long as it is a method capable of collecting a predetermined amount of inorganic fibers over the entire area of the inorganic fiber sheet, and examples thereof include the collection method by the sample collection means described in the section of "A. Fiber diameter measuring device 2. Sample collection means" above.

[0203] The inorganic fiber sheet to be subjected to the sample collection step contains inorganic fibers. Further, the inorganic fiber sheet to be subjected to the sample collection step is preferably subjected to needling treatment. Regarding the inorganic fiber sheet, the same content as that described in the section of "A. Fiber diameter measuring device 1. Inorganic fiber sheet" above can be adopted.

[0204] 2. Measurement step In the measurement step of the present invention, the fiber diameter of the collected inorganic fibers is measured.

[0205] As a method for measuring the fiber diameter of inorganic fibers, known methods can be applied, and examples thereof include the measurement method by the measurement means described in the section of "A. Fiber diameter measuring device 3. Measurement means" above.

[0206] Regarding other aspects of the measurement step, the same content as that described in the section of "A. Fiber diameter measuring device 3. Measurement means" above can be adopted.

[0207] 3. Other steps In the fiber diameter measurement method of the present invention, it is preferable to perform a step of removing dust, fibers, etc. generated during the manufacturing process of the inorganic fiber sheet and dust and fibers floating in the air immediately before the sample collection step.

[0208] D. Method for manufacturing inorganic fiber sheet Next, a method for manufacturing the inorganic fiber sheet of the present invention will be described. The method for manufacturing the inorganic fiber sheet of the present invention includes a sample collection step of collecting a predetermined amount of the inorganic fibers from the inorganic fiber sheet by a collection method capable of collecting the predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet containing the inorganic fibers, and a measurement step of measuring the fiber diameter of the collected inorganic fibers.

[0209] FIG. 4 is a schematic diagram showing an example of the method for manufacturing the inorganic fiber sheet of the present invention. FIG. 4 is an example of a manufacturing method for measuring the fiber diameter of inorganic fibers in a long inorganic fiber sheet 1. As illustrated in FIG. 4, first, a long inorganic fiber precursor sheet 1a is conveyed to a firing means 4 by a conveying roll 13, and the continuously conveyed inorganic fiber precursor sheet 1a is fired by the firing means 4 to obtain an inorganic fiber sheet 1. Next, while continuously conveying the long inorganic fiber sheet 1 by conveying rolls 11 and 12, inorganic fibers are sucked from the lower surface of the inorganic fiber sheet 1 during conveyance by a sample moving means 2a (suction means) to collect the inorganic fibers. Then, the fiber diameter of the collected inorganic fibers is measured by a measuring means 3.

[0210] According to the present invention, in the sample collection step, since a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet, the collected inorganic fibers can be regarded as representative of the inorganic fibers in the inorganic fiber sheet. Therefore, the continuous safety of the fiber diameter of the inorganic fibers in the inorganic fiber sheet can be guaranteed, and the reliability of the measured average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers can be improved. Specifically, in the case of a long inorganic fiber sheet, the average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers over the entire area of the inorganic fiber sheet can be guaranteed. Thus, an inorganic fiber sheet with a higher level of safety can be provided.

[0211] Also, according to the present invention, in the sample collection step, since the inorganic fibers are collected by a method capable of collecting a predetermined amount of inorganic fibers over the entire area of the inorganic fiber sheet, the inorganic fiber sheet is not punched out or cut out for sample collection. Therefore, it is possible to measure the fiber diameter of the inorganic fibers in the inorganic fiber sheet not only after the production of the inorganic fiber sheet but also during the production of the inorganic fiber sheet. That is, it is possible to measure the fiber diameter of the inorganic fibers in the inorganic fiber sheet online. Therefore, it is possible to manage the average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers in the inorganic fiber sheet online.

[0212] Also, according to the present invention, in the sample collection step, since the inorganic fibers are collected by a method capable of collecting a predetermined amount of inorganic fibers over the entire area of the inorganic fiber sheet, the inorganic fiber sheet is not punched out or cut out for sample collection, so it is possible to suppress the appearance of the inorganic fiber sheet from being damaged. Therefore, it is possible to obtain an inorganic fiber sheet with good appearance even after the fiber diameter measurement.

[0213] Hereinafter, each step in the method for manufacturing the inorganic fiber sheet of the present invention will be described. Note that each step in the method for manufacturing the inorganic fiber sheet of the present invention may be described by taking each step in the method for manufacturing an alumina fiber sheet, which is one aspect of the inorganic fiber sheet of the present invention, as an example.

[0214] 1. Inorganic fiber sheet manufacturing step The method for manufacturing the inorganic fiber sheet of the present invention includes an inorganic fiber sheet manufacturing step of manufacturing an inorganic fiber sheet before the sample collection step. In the above inorganic fiber sheet manufacturing step, the method for manufacturing the inorganic fiber sheet is not particularly limited.

[0215] In the above inorganic fiber sheet manufacturing process, for example, a long inorganic fiber sheet can be continuously manufactured. Among them, the above inorganic fiber sheet manufacturing process preferably includes a preparation step of preparing an inorganic fiber precursor sheet containing an inorganic fiber precursor, and a firing step of continuously firing the above inorganic fiber precursor sheet to obtain the above inorganic fiber sheet. This is because when continuously manufacturing an inorganic fiber sheet, the fiber diameter distribution is likely to fluctuate, and it is particularly difficult to obtain a fiber diameter measurement sample representative of the inorganic fiber sheet.

[0216] Examples of the above inorganic fiber sheet manufacturing process include a first aspect having a preparation step of preparing an inorganic fiber precursor sheet containing an inorganic fiber precursor, and a firing step of firing the above inorganic fiber precursor sheet to obtain the above inorganic fiber sheet, and a second aspect having a papermaking sheet manufacturing process of manufacturing an inorganic fiber sheet that is a papermaking sheet. Hereinafter, each aspect will be described.

[0217] (1) The first aspect of the inorganic fiber sheet manufacturing process The manufacturing method of the inorganic fiber sheet of the present invention can include a preparation step of preparing an inorganic fiber precursor sheet containing an inorganic fiber precursor before the sample collection step, and a firing step of firing the above inorganic fiber precursor sheet to obtain the above inorganic fiber sheet.

[0218] (1-1) Preparation step The preparation step in this aspect is a step of preparing an inorganic fiber precursor sheet containing an inorganic fiber precursor. In the manufacturing method of an alumina fiber sheet, which is one aspect of the inorganic fiber sheet of the present invention, the preparation step is a step of preparing an alumina fiber precursor sheet containing an alumina fiber precursor.

[0219] As a method for manufacturing an inorganic fiber precursor sheet, a known method can be applied and is not particularly limited. For example, the preparation process may include a preparation process for preparing a spinning solution, a spinning process for spinning the spinning solution to form an inorganic fiber precursor, and an inorganic fiber precursor sheet forming process for accumulating the inorganic fiber precursors to form an inorganic fiber precursor sheet. In the spinning process, for example, a blowing method, a spinning method, or the like can be used. Also, in the spinning process, a short fiber-shaped inorganic fiber precursor can be obtained.

[0220] Here, as described above, in the case of short fibers, it is difficult to control the fiber diameter compared to long fibers. In the first aspect of the inorganic fiber sheet manufacturing process, in the spinning process, as described above, since a short fiber-shaped inorganic fiber precursor is obtained, the inorganic fiber sheet obtained in the first aspect of the inorganic fiber sheet manufacturing process is difficult to obtain a safety confirmation without inspection and is useful for the present invention.

[0221] As a method for manufacturing an alumina fiber precursor sheet, a known method can be applied and is not particularly limited. For example, a method of preparing a spinning solution containing an aluminum compound, spinning the spinning solution to form an alumina fiber precursor, accumulating the alumina fiber precursors to form an alumina fiber precursor sheet, and subjecting the alumina fiber precursor sheet to needling treatment can be mentioned.

[0222] The preparation of the spinning solution can be carried out according to a conventional method. As the spinning solution, for example, it can be prepared by adding a silicon compound to an aqueous solution of basic aluminum chloride prepared by dissolving aluminum in hydrochloric acid. As the silicon compound, silica sol is preferably used, but other water-soluble silicon compounds such as tetraethyl silicate and water-soluble siloxane derivatives can also be used.

[0223] In the spinning solution, the ratio of aluminum and silicon is Al 2 O 3 / SiO 2When converted to the mass ratio, it is preferably in the range of 60:40 to 98:2, more preferably in the range of 65:35 to 95:5, and particularly preferably in the range of 70:30 to 80:20. If the silicon component is too much, fiberization becomes easy but the heat resistance may be significantly reduced. On the other hand, if the silicon component is too little, the fiber may be prone to embrittlement.

[0224] In addition, in order to improve the spinnability, it is preferable that the spinning solution contains a spinning aid. Examples of the spinning aid include water-soluble organic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, starch, and cellulose derivatives.

[0225] The spinning solution can be prepared, for example, by adding a silicon compound and an organic polymer to an aqueous solution of basic aluminum chloride and appropriately concentrating it. The viscosity of the spinning solution at room temperature can be, for example, about 10 poises or more and 100 poises or less.

[0226] The formation of the alumina fiber precursor from the spinning solution can be carried out according to a conventional method. For example, the formation of the alumina fiber precursor from the spinning solution includes the blowing method of supplying the spinning solution into a high-speed spinning air stream. The nozzle of the blowing method includes one in which a spinning solution nozzle is installed inside an air stream nozzle that generates a spinning air stream, and one in which a spinning solution nozzle is installed so as to supply the spinning solution from the outside of the spinning air stream, and either can be used. When spinning by the above blowing method, for example, a method can be used in which an endless belt made of wire mesh is installed so as to be substantially perpendicular to the spinning air stream, and while rotating this, the spinning air stream containing the alumina fiber precursor formed thereon is collided. The alumina fiber precursor formed by this spinning usually has a thickness of several μm and a length of several tens of mm to several hundreds of mm.

[0227] By accumulating the alumina fiber precursor, an alumina fiber precursor sheet can be obtained. When manufacturing the alumina fiber precursor sheet, the alumina fiber precursor may be accumulated to form a single-layer sheet, or the thin-layer sheets obtained by accumulating the alumina fiber precursor may be laminated.

[0228] The method of laminating the thin-layer sheets is not particularly limited. For example, the method for manufacturing a laminated sheet made of an alumina fiber precursor disclosed in Japanese Patent Application Laid-Open No. 2000-80547 can be applied. Specifically, the alumina fiber precursor is deposited on an accumulating device to form a thin-layer sheet of the alumina fiber precursor, and this thin-layer sheet is continuously drawn out from the accumulating device and sent to a folding device, folded to a predetermined width and stacked while being continuously moved in a direction perpendicular to the folding direction. The method for manufacturing a laminated sheet made of an alumina fiber precursor can be applied. In this method for manufacturing a laminated sheet made of an alumina fiber precursor, the thin-layer sheet is continuously drawn out from the accumulating device, folded and stacked in the advancing direction of the thin-layer sheet while being continuously moved in a lateral direction with respect to the folding direction. Therefore, the folding width becomes equal to the width of the laminated sheet to be formed. As a result, both end portions in the width direction of the thin-layer sheet are dispersed in the formed laminated sheet, so that the basis weight of the laminated sheet becomes uniform over the entire laminated sheet. Such a method for manufacturing a laminated sheet made of an alumina fiber precursor is one of the manufacturing methods that form a sheet shape after undergoing lamination by folding ninety-nine times.

[0229] Note that the needling treatment will be described later.

[0230] (1-2) Firing step The firing step in this embodiment is a step of firing the inorganic fiber precursor sheet. The firing step is preferably a step of continuously firing the inorganic fiber precursor sheet to obtain an inorganic fiber sheet.

[0231] The firing of the inorganic fiber precursor sheet can be carried out according to a conventional method. Note that the firing temperature is the same as that described in the section of "B. Manufacturing apparatus for inorganic fiber sheet" above.

[0232] (1-3) Needling process In this embodiment, the method for manufacturing an inorganic fiber sheet may have a needling process of subjecting an inorganic fiber precursor sheet to a needling treatment before or after the firing process. This is because the present invention is suitable for an inorganic fiber sheet subjected to a needling treatment. Among them, when the inorganic fiber sheet manufacturing process of this embodiment has a needling process, it is preferable to have a needling process before the firing process. The present invention is useful for an inorganic fiber sheet obtained by firing an inorganic fiber precursor sheet subjected to a needling treatment.

[0233] By subjecting the inorganic fiber precursor sheet to a needling treatment, an inorganic fiber precursor sheet having a large mechanical strength in which the inorganic fiber precursors are oriented also in the thickness direction of the inorganic fiber precursor sheet can be obtained.

[0234] For the needling treatment, a known method can be applied and is not particularly limited. For example, it can be the same as the needling treatment disclosed in International Publication No. 2016 / 152795.

[0235] The number of needling strokes is, for example, 1 stroke / cm 2 to 50 strokes / cm or more 2 and can be set as follows. Generally, the greater the number of strokes, the greater the bulk density and peel strength of the obtained inorganic fiber precursor sheet.

[0236] (2) Second aspect of the inorganic fiber sheet manufacturing process The method for manufacturing an inorganic fiber sheet of the present invention may have a process for manufacturing a paper-made sheet, which is an inorganic fiber sheet, before the sample collection process.

[0237] The inorganic fiber sheet, which is a sheet formed by papermaking, can be manufactured by a known method. The sheet forming process can include, for example, a papermaking process of forming a slurry containing inorganic fibers, water, and a binder, and a drying process of drying the sheet obtained in the papermaking process. Further, the sheet forming process may include a fiber disintegration process of disintegrating inorganic fibers and a slurry preparation process of preparing the slurry containing the disintegrated inorganic fibers as the inorganic fibers before the papermaking process. Each process can apply known techniques.

[0238] The inorganic fibers contained in the slurry may be, for example, those obtained by spinning long fibers and cutting or pulverizing them into short fibers, or those spun as short fibers. Among them, the inorganic fibers are preferably those spun as short fibers. Here, as described above, in the case of short fibers, it is difficult to control the fiber diameter compared to long fibers. Therefore, the present invention is suitable for inorganic fibers spun as short fibers, for which it is difficult to obtain assurance of safety without inspection.

[0239] The inorganic fiber sheet manufacturing process of this aspect may optionally include a needling process of subjecting the inorganic fiber sheet to a needling treatment after the sheet forming process.

[0240] (3) Another aspect of the inorganic fiber sheet manufacturing process In the method for manufacturing an inorganic fiber sheet of the present invention, a needling process of subjecting the inorganic fiber sheet to a needling treatment may be included before the sample collection process. That is, the inorganic fiber sheet manufacturing process may include a needling process regardless of the method for manufacturing the inorganic fiber sheet. The present invention is useful for an inorganic fiber sheet subjected to a needling treatment.

[0241] 2. Sample collection process The sample collection process in the present invention is an inorganic process of collecting the inorganic fibers from the inorganic fiber sheet by a collection method capable of collecting a predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet.

[0242] As a method for collecting inorganic fibers, any method can be used as long as a predetermined amount of inorganic fibers can be collected over the entire area of the inorganic fiber sheet, and examples thereof include the collection method using the sample collection means described in the section of "A. Fiber diameter measuring device 2. Sample collection means" above.

[0243] In the present invention, it is preferable to continuously perform the firing step and the sample collection step. This is because inorganic fibers for measuring the fiber diameter can be collected from the inorganic fiber sheet online.

[0244] The inorganic fiber sheet used in the sample collection step is preferably subjected to needling treatment. By performing the needling step, an inorganic fiber sheet subjected to needling treatment can be obtained.

[0245] 3. Measurement step The measurement step in the present invention is a step of measuring the fiber diameter of the collected inorganic fibers.

[0246] As a method for measuring the fiber diameter of inorganic fibers, known methods can be applied, and examples thereof include the measurement method using the measurement means described in the section of "A. Fiber diameter measuring device 3. Measurement means" above.

[0247] Regarding other aspects of the measurement step, the same content as that described in the section of "A. Fiber diameter measuring device 3. Measurement means" above can be adopted.

[0248] In the present invention, it is preferable to continuously perform the firing step, the sample collection step, and the measurement step. This is because the fiber diameter of the inorganic fibers in the inorganic fiber sheet can be measured online.

[0249] 4. Feedback and control In the present invention, when the fiber diameter measured in the above measurement step deviates from a preset predetermined range, the result is fed back, and the production conditions of the inorganic fiber precursor sheet and / or the firing conditions in the above firing step are controlled so that the fiber diameter falls within the above predetermined range. It is possible to confirm online the average fiber diameter, fluctuations in the fiber diameter distribution, and deviations from the allowable range of inorganic fibers, and by feeding back the results and controlling the production conditions of the inorganic fiber precursor sheet and / or the firing conditions in the firing step, the average fiber diameter, fiber diameter distribution, etc. of the inorganic fibers can be kept within the allowable range.

[0250] When the measured fiber diameter deviates from a preset predetermined range, the result is fed back, and the production conditions of the inorganic fiber precursor sheet and / or the firing conditions in the firing step are controlled so that the fiber diameter falls within the predetermined range. On the other hand, if the measured fiber diameter is within the predetermined range, the current production conditions of the inorganic fiber precursor sheet and the firing conditions in the firing step are maintained.

[0251] The preset predetermined range of the fiber diameter is, for example, a range of values appropriately set according to the specifications of the inorganic fiber sheet and the like.

[0252] Specifically, it is confirmed whether the average fiber diameter, standard deviation of the fiber diameter distribution, minimum fiber diameter, maximum fiber diameter, etc. meet the specifications or deviate, or whether they meet the target range or deviate. Alternatively, it is confirmed whether there are singular points in the fiber diameter (for example, the presence or absence of fibers with a fiber diameter of 3 μm or less).

[0253] The method of controlling the production conditions of the inorganic fiber precursor sheet and / or the firing conditions in the firing step for adjusting the fiber diameter can be appropriately selected according to whether the fiber diameter meets the predetermined range or deviates.

[0254] As a method for controlling the production conditions of an inorganic fiber precursor sheet for adjusting the fiber diameter, there are control of the preparation conditions of the spinning solution, control of the spinning conditions, and the like. For example, as a method for controlling the preparation conditions of the spinning solution for adjusting the fiber diameter, control of the viscosity of the spinning solution and the like can be mentioned.

[0255] Further, as a method for controlling the firing conditions in the firing process for adjusting the fiber diameter, for example, control of the firing temperature and the like can be mentioned.

[0256] Feedback and control may be performed automatically or manually.

[0257] 5. Other Processes The method for producing an inorganic fiber sheet of the present invention may have other processes as necessary in addition to the above processes.

[0258] In the method for producing an inorganic fiber sheet of the present invention, so that floating fibers, dust, etc. deposited and / or adhered to the inorganic fiber sheet from the inside of each process or the atmosphere do not affect the measurement result of the fiber diameter, immediately before the above sample collection process, it is preferable to perform a process of removing floating fibers, dust, etc. deposited and / or adhered to the inorganic fiber sheet from the inside of each process or the atmosphere.

[0259] The method for producing an inorganic fiber sheet of the present invention may have a winding process of winding a long inorganic fiber sheet into a roll shape, for example, after the measurement process. Alternatively, the method for producing an inorganic fiber sheet of the present invention may have a cutting process of cutting the inorganic fiber sheet, for example, between the firing process and the measurement process.

[0260] The method for producing an alumina fiber sheet, which is one embodiment of the inorganic fiber sheet of the present invention, may have an impregnation process of impregnating the alumina fiber sheet with a binder solution and a drying process of drying the binder solution-impregnated alumina fiber sheet obtained by impregnating the alumina fiber sheet with the binder solution, for example, after the measurement process.

[0261] 6. Other Embodiments of the Method for Producing an Inorganic Fiber Sheet Another embodiment of the method for manufacturing an inorganic fiber sheet of the present invention includes a preparation step of preparing an inorganic fiber precursor sheet containing an inorganic fiber precursor and subjected to needling treatment, a firing step of continuously firing the inorganic fiber precursor sheet to obtain an inorganic fiber sheet containing inorganic fibers and subjected to needling treatment, and a sample collection step of collecting a predetermined amount of the inorganic fibers from the inorganic fiber sheet by a collection method capable of collecting the inorganic fibers over the entire area of the inorganic fiber sheet, and a measurement step of measuring the fiber diameter of the collected inorganic fibers.

[0262] Note that the present invention is not limited to the above embodiments. The above embodiments are examples, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operational effects is included in the technical scope of the present invention.

Example

[0263] Examples and reference examples are shown below to explain the present invention in more detail.

[0264] [Example 1] A raw roll of a long crystalline alumina / silica fiber sheet (manufactured by Mitsubishi Chemical Corporation, Maftex (registered trademark)) with a basis weight of 2400 gsm, a width of 150 mm, and a length of 500 mm was prepared. An ultrasonic dry cleaner for webs (manufactured by Noborikyo Co., Ltd., HG Cleaner VUV-HGv-130) was used as a nozzle head, and inorganic fibers were collected at a suction rate of 500 L / min while discharging compressed air at 0.3 MPa. The nozzle head was placed on the upper surface of the crystalline alumina / silica fiber sheet. In this case, the feed rate of the crystalline alumina / silica fiber sheet was 500 mm / min, and a PTFE membrane filter (manufactured by Merck, Omnipore) with a pore diameter of 1 μm was used as the filter for inorganic fiber collection. The amount of the collected inorganic fibers was 0.05 g.

[0265] Next, with respect to the recovered inorganic fibers, the recovered inorganic fibers were processed by a method compliant with EU Regulation COMMISSION REGULATION (EC) No 761 / 2009, and the diameters of approximately 300 inorganic fibers were measured using an optical microscope.

[0266] [Reference Example 1] Regarding the crystalline alumina / silica fiber sheet after recovering the inorganic fibers in Example 1, in compliance with EU Regulation COMMISSION REGULATION (EC) No 761 / 2009, six locations were punched out evenly in the width direction of the alumina / silica fiber sheet with a cork borer of φ25 mm, and the stock solution of the representative sample in the width direction (width representative sample) was obtained by dispersing the six test pieces in 300 mL of water. Next, in the same procedure as the preparation of the stock solution of the width representative sample above, the stock solution of the width representative sample was prepared every 100 mm in the longitudinal direction, and in total with the stock solution of the width representative sample above, the stock solutions of the width representative samples at five locations were obtained from the alumina / silica fiber sheet.

[0267] Next, after thoroughly stirring the obtained stock solution of the width representative sample, 50 mL of it was taken out into an empty container, and 250 mL of water was added and stirred thoroughly to obtain a diluted solution of the width representative sample. The above operation for obtaining the diluted solution was performed on all of the stock solutions of the width representative samples at the five locations described above to prepare diluted solutions respectively.

[0268] Next, using an optical microscope, by measuring the diluted solutions of each width representative sample, the diameters of approximately 300 inorganic fibers serving as representative samples in each width direction were measured. Each width representative sample was numbered from 1 to 5 in order from one side in an arbitrary longitudinal direction, and the respective measured values were distinguished.

[0269] [Reference Example 2] 60 mL each was taken from each of the wide-width representative sample dilutions prepared in Reference Example 1, mixed in an empty container, and stirred well to obtain 300 mL of an alumina / silica fiber dispersion. Since the alumina / silica fiber dispersion is a mixture of each wide-width representative sample, it can be said to be one of the representative samples of the alumina / silica fiber sheet. About 300 inorganic fiber diameters representative of the alumina / silica fiber sheet were measured by measuring the above alumina / silica fiber dispersion using an optical microscope.

[0270] [Reference Example 3] 10 mL each was taken from each of the wide-width representative sample stock solutions prepared in Reference Example 1, mixed with 250 mL of water in an empty container, and stirred well to obtain 300 mL of an alumina / silica fiber dispersion. Since the alumina / silica fiber dispersion is a mixture of each wide-width representative sample, it can be said to be one of the representative samples of the alumina / silica fiber sheet. About 300 inorganic fiber diameters representative of the alumina / silica fiber sheet were measured by measuring the above alumina / silica fiber dispersion using an optical microscope.

[0271]

Table 1

[0272] [Evaluation] The measurement results of the number average fiber diameter and the detected number of fibers with a fiber diameter of less than 3.0 μm in Example 1 and Reference Examples 1 to 3 are shown in Table 1 and FIG. 5. In FIG. 5, Reference Example 1 is plotted as the wide-width representatives 1, 2, 3, 4, and 5 in Table 1 in order from the left. Also, when the standard deviation calculated from the five points of Reference Example 1 is σ (sigma), the average value ±σ is shown as a broken line, the average value ±2σ is shown as a one-dot chain line, and the average value ±3σ is shown as a long two-dot chain line. The average fiber diameter of Example 1 is within the variation of the average fiber diameters of the five types of samples of Reference Example 1, which is a representative sample in the wide-width direction (since Reference Example 1 is a representative in the wide-width direction in samples made from the same crystalline alumina / silica fiber sheet, the probability density of each value is considered to follow a normal distribution and the variation is within the average value ±3σ), and shows a value close to the average fiber diameters of Reference Examples 2 and 3, which are representative samples of the alumina / silica fiber sheet. From these results, it was found that the method for measuring the fiber diameter of the inorganic fibers disclosed in the present invention can obtain the same results as the conventional offline method for measuring the fiber diameter in accordance with EU Regulation (EC) No 761 / 2009. It was found that the same results can be obtained as those of the conventional offline method for measuring the fiber diameter in accordance with EU Regulation (EC) No 761 / 2009.

Explanation of Signs

[0273] 1 … Inorganic fiber sheet 1a … Inorganic fiber precursor sheet 2 … Sample collection means 2a … Sample moving means 2b … Supply means 2c … Sample recovery means 2d … Vibration means 3 … Measuring means 4 … Firing means 10 … Fiber diameter measuring device 11, 12, 13 … Conveyor rolls 20 … Manufacturing device for inorganic fiber sheet

Claims

1. A fiber diameter measuring device for measuring the fiber diameter of inorganic fibers in an inorganic fiber sheet containing inorganic fibers, comprising: sample collection means capable of collecting a predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet; measuring means for measuring the fiber diameter of the collected inorganic fibers and the sample collection means is disposed on one or both sides of the inorganic fiber sheet and has sample moving means for moving the inorganic fibers, wherein the sample moving means is suction means for sucking the inorganic fibers. A fiber diameter measuring device.

2. A fiber diameter measuring device for measuring the fiber diameter of inorganic fibers in an inorganic fiber sheet containing inorganic fibers, comprising: sample collection means capable of collecting a predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet; measuring means for measuring the fiber diameter of the collected inorganic fibers and the sample collection means has pretreatment means for assisting in the collection of the inorganic fibers, wherein the pretreatment means is physical non-contact means that is physically non-contact with the inorganic fiber sheet. A fiber diameter measuring device.

3. A fiber diameter measuring device for measuring the fiber diameter of inorganic fibers in an inorganic fiber sheet containing inorganic fibers, comprising: sample collection means capable of collecting a predetermined amount of the inorganic fibers over the entire area of the inorganic fiber sheet; measuring means for measuring the fiber diameter of the collected inorganic fibers and the sample collection means has pretreatment means for assisting in the collection of the inorganic fibers, wherein the sample collection means has vibration means for applying vibration to the inorganic fiber sheet as the pretreatment means. A fiber diameter measuring device.

4. The fiber diameter measuring device according to claim 2 or claim 3, wherein the sample collection means is disposed on one or both sides of the inorganic fiber sheet and has sample moving means for moving the inorganic fibers.

5. The fiber diameter measuring device according to claim 1, wherein the sample collection means has pretreatment means for assisting in the collection of the inorganic fibers.

6. The fiber diameter measuring device according to claim 5, wherein the pretreatment means is physical non-contact means that is physically non-contact with the inorganic fiber sheet.

7. The fiber diameter measuring device according to claim 2 or claim 6, wherein the physical non-contact means is supply means for supplying gas or liquid to the inorganic fiber sheet from one or both sides of the inorganic fiber sheet.

8. The fiber diameter measuring device according to claim 5, wherein the pretreatment means is a physical contact means that physically contacts the inorganic fiber sheet.

9. The fiber diameter measuring device according to claim 5, wherein the sample collection means has vibration means for applying vibration to the inorganic fiber sheet as the pretreatment means.

10. The fiber diameter measuring device according to any one of claims 1 to 9, wherein the sample collection means has sample collection means for collecting the inorganic fiber.

11. A manufacturing device for an inorganic fiber sheet, comprising the fiber diameter measuring device according to any one of claims 1 to 10.

12. The manufacturing device for an inorganic fiber sheet according to claim 11, comprising firing means for continuously firing an inorganic fiber precursor sheet containing an inorganic fiber precursor on the upstream side of the fiber diameter measuring device.

13. A fiber diameter measuring method for measuring the fiber diameter of the inorganic fiber in an inorganic fiber sheet containing an inorganic fiber, a sample collection step of collecting the inorganic fiber from the inorganic fiber sheet by a collection method capable of collecting a predetermined amount of the inorganic fiber over the entire area of the inorganic fiber sheet, a measurement step of measuring the fiber diameter of the collected inorganic fiber and having, in the sample collection step, the inorganic fiber is moved by sample moving means disposed on one or both sides of the inorganic fiber sheet and moving the inorganic fiber, The fiber diameter measuring method, wherein the sample moving means is suction means for sucking the inorganic fiber.

14. A fiber diameter measuring method for measuring the fiber diameter of the inorganic fiber in an inorganic fiber sheet containing an inorganic fiber, a sample collection step of collecting the inorganic fiber from the inorganic fiber sheet by a collection method capable of collecting a predetermined amount of the inorganic fiber over the entire area of the inorganic fiber sheet, a measurement step of measuring the fiber diameter of the collected inorganic fiber and having, in the sample collection step, the collection of the inorganic fiber is assisted by pretreatment means for assisting the collection of the inorganic fiber, The fiber diameter measuring method, wherein the pretreatment means is physical non-contact means that is physically non-contact with the inorganic fiber sheet.

15. A fiber diameter measuring method for measuring the fiber diameter of the inorganic fiber in an inorganic fiber sheet containing an inorganic fiber, a sample collection step of collecting the inorganic fiber from the inorganic fiber sheet by a collection method capable of collecting a predetermined amount of the inorganic fiber over the entire area of the inorganic fiber sheet, A measuring step of measuring the fiber diameter of the inorganic fiber taken; and having; In the sample collection step, the collection of the inorganic fiber is assisted by pretreatment means for assisting the collection of the inorganic fiber; A fiber diameter measurement method characterized by using vibration means for applying vibration to the inorganic fiber sheet as the pretreatment means.

16. In the sample collection step, the inorganic fiber is moved by sample moving means disposed on one or both sides of the inorganic fiber sheet and moving the inorganic fiber. The fiber diameter measurement method according to claim 14 or claim 15.

17. In the sample collection step, the collection of the inorganic fiber is assisted by pretreatment means for assisting the collection of the inorganic fiber. The fiber diameter measurement method according to claim 13.

18. A sample collection step of collecting the inorganic fiber from the inorganic fiber sheet by a collection method capable of collecting a predetermined amount of the inorganic fiber over the entire area of the inorganic fiber sheet containing the inorganic fiber; A measuring step of measuring the fiber diameter of the collected inorganic fiber; and having; In the sample collection step, the inorganic fiber is moved by sample moving means disposed on one or both sides of the inorganic fiber sheet and moving the inorganic fiber; The sample moving means is a suction means for sucking the inorganic fiber. A method for manufacturing an inorganic fiber sheet.

19. A sample collection step of collecting the inorganic fiber from the inorganic fiber sheet by a collection method capable of collecting a predetermined amount of the inorganic fiber over the entire area of the inorganic fiber sheet containing the inorganic fiber; A measuring step of measuring the fiber diameter of the collected inorganic fiber; and having; In the sample collection step, the collection of the inorganic fiber is assisted by pretreatment means for assisting the collection of the inorganic fiber; The pretreatment means is a physically non-contact means that is physically non-contact with the inorganic fiber sheet. A method for manufacturing an inorganic fiber sheet.

20. A sample collection step of collecting the inorganic fiber from the inorganic fiber sheet by a collection method capable of collecting a predetermined amount of the inorganic fiber over the entire area of the inorganic fiber sheet containing the inorganic fiber; A measuring step of measuring the fiber diameter of the collected inorganic fiber; and having; In the sample collection step, the collection of the inorganic fiber is assisted by pretreatment means for assisting the collection of the inorganic fiber; A method for manufacturing an inorganic fiber sheet, characterized by using vibration means for applying vibration to the inorganic fiber sheet as the pretreatment means.

21. In the sample collection step, the method for manufacturing an inorganic fiber sheet according to claim 19 or claim 20, wherein the inorganic fibers are moved by sample moving means that is disposed on one or both sides of the inorganic fiber sheet and moves the inorganic fibers.

22. In the sample collection step, the method for manufacturing an inorganic fiber sheet according to claim 18, wherein the collection of the inorganic fibers is assisted by pretreatment means for assisting the collection of the inorganic fibers.

23. Before the sample collection step, a preparation step of preparing an inorganic fiber precursor sheet containing an inorganic fiber precursor, and a firing step of continuously firing the inorganic fiber precursor sheet to obtain the inorganic fiber sheet, The method for manufacturing an inorganic fiber sheet according to any one of claims 18 to 22.

24. When the fiber diameter measured in the measurement step deviates from a preset predetermined range, the result is fed back so that the fiber diameter falls within the predetermined range, and the manufacturing conditions of the inorganic fiber precursor sheet and / or the firing conditions in the firing step are controlled. The method for manufacturing an inorganic fiber sheet according to claim 23.

25. The inorganic fiber sheet used in the sample collection step is an inorganic fiber sheet subjected to needling treatment. The method for manufacturing an inorganic fiber sheet according to any one of claims 18 to 24.

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