Manufacturing method of sheet-like article

Abstract

To provide a method of manufacturing a sheet-like article by moving a sheet while maintaining quality of the sheet.SOLUTION: A manufacturing method of a sheet-like article 1 includes: a sheet forming process of forming a sheet of a desire shape or cutting out a sheet 10 of the desired shape from a raw material sheet 10A; and a transfer process of transferring the sheet 10 obtained in the sheet forming process. In the sheet forming process, the sheet 10, which has a highly permeable area R1 with relatively high permeability and a low permeable area R2 with relatively low permeability in a plan view, is formed. In the transfer process, the sheet 10 is held by making a suction pad 42 connected to a suction device 41 suck the low permeable area R2 to move the sheet 10 to a transfer destination.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a sheet-like article. [Background technology]

[0002] Conventionally, a raw material is cut to form a sheet of a predetermined shape, and the sheet is transferred to a downstream process. For example, Patent Document 1 describes a sheet processing system that includes a processing device that cuts a long sheet material into a predetermined shape to form a plurality of sheets, and a transfer device that accumulates the sheets to form a sheet bundle and transfers the sheet bundle to a downstream process. Patent Document 2 describes a fiber sheet stacking device that cuts a raw material into strips of a predetermined length to form a fiber sheet, and has a supply mechanism that supplies the fiber sheet to a transport conveyor, and a robot that transports the fiber sheet on the transport conveyor to a stacking area and stacks the transported fiber sheet on the fiber sheet of a fiber sheet stack that has already been stacked in the stacking area. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-150181 A [Patent Document 2] JP 2017-217895 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the sheet processing system of Patent Document 1, the transfer device uses a robot hand to grip the sheet bundle and transfer the sheet bundle, so there is a risk that the sheets constituting the sheet bundle may bear marks caused by the robot hand gripping them. In addition, in the fiber sheet stacking device of Patent Document 2, a fiber sheet is adsorbed to a suction tube held by a robot, and after being transported to the stacking area, the transported fiber sheet is superimposed on a fiber sheet of an already stacked fiber sheet stack and pressed, but in Patent Document 2, in the state where the fiber sheets are superimposed on each other, the fiber sheet adsorbed to the suction tube is irradiated with laser light to heat and melt the fiber sheets, thereby fusing them together, and thus melting marks remain on each fiber sheet. As described above, with the techniques of Patent Documents 1 and 2, it is difficult to transport a sheet while maintaining the quality of the sheet.

[0005] An object of the present invention is to provide a method for transferring a sheet while maintaining its quality, and producing a sheet-like article. [Means for solving the problem]

[0006] The present invention relates to a method for producing a sheet-like article. In one embodiment, a sheet forming step of forming a sheet having a desired shape or cutting a sheet having a desired shape from a raw material sheet; In one embodiment, it is preferable to have a transferring step of transferring the sheet obtained in the sheet forming step. In one embodiment, in the sheet forming step, it is preferable to form a sheet having, in a plan view, a high-air-permeability region having relatively high air-permeability and a low-air-permeability region having relatively low air-permeability. In one embodiment, in the transfer step, it is preferable that an adsorption pad connected to a suction device is adsorbed to the low-breathability region to hold the sheet, and the sheet is moved to the destination. Effect of the Invention

[0007] According to the present invention, a sheet-like article can be manufactured by transferring the sheet while maintaining its quality. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing an outline of a sheet-like article production apparatus used in one embodiment of the production method of the present invention. [Diagram 2] FIG. 2 is a plan view showing a schematic diagram of a sheet formed in the sheet forming step according to this embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a perspective view of the sheet shown in FIG. [Diagram 5] FIG. 5 is an end view taken along line III-III in FIG. [Figure 6] 6(a) and (b) are schematic plan views for explaining a method of correcting the cutting position, where FIG. 6(a) is a plan view showing the state before correction and FIG. 6(b) is a plan view showing the state after correction. [Figure 7] FIG. 7 is a plan view showing an example of a method for identifying a gradation area. [Figure 8] FIG. 8(a) is a plan view showing a schematic view of a portion of the sheet to which the suction pad is attached, and FIG. 8(b) is a cross-sectional view taken along line VIIb-VIIb in FIG. 8(a). [Figure 9] 9(a) and (b) are plan views showing an example of a portion where a plurality of suction pads are attached, and correspond to FIG. 8(a). [Figure 10] 10(a) and (b) are plan views that typically show modified examples of the sheet shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described below based on preferred embodiments with reference to the drawings. Fig. 1 shows an outline of a manufacturing apparatus 100 used in a preferred embodiment of the method for manufacturing a sheet-like article of the present invention. The manufacturing apparatus 100 manufactures a sheet-like article 1. The manufacturing apparatus 100 includes a sheet forming section 30 that cuts out a sheet 10 having a desired shape from a raw material sheet 10A, a transfer section 40 that transfers the sheet 10 obtained in the sheet forming section 30, and a processing section 50 that processes the sheet 10 transferred by the transfer section 40 to form a sheet-like article 1. The transfer section 40 includes a robot arm (not shown) and a suction device 41 held at the tip of the robot arm. The suction device 41 is connected to an air pressure source (not shown) or a negative pressure source (not shown). The suction device 41 can transmit a force generated in a vacuum ejector by compressed air supplied from the air pressure source or a negative pressure from a negative pressure source (not shown) to the suction pad 42, thereby applying a desired suction force to the suction pad 42. The suction device 41 has a control unit capable of controlling the suction force applied to the suction pad 42, and when holding the sheet 10, the suction force is applied to the suction pad 42, and the sheet 10 can be transferred to the destination by releasing the held state of the sheet 10 by releasing the suction force at the destination. Examples of the negative pressure source include various known suction pumps.

[0010] The method for manufacturing the sheet-like article 1 using the manufacturing apparatus 100 includes a sheet forming step of cutting out a sheet 10 having a desired shape from a raw material sheet 10A, and a transfer step of transferring the sheet 10 obtained in the sheet forming step. In addition to these steps, the manufacturing method of this embodiment also includes a processing step. The processing step is performed after the transfer step.

[0011] 2 to 4 show the sheet 10 obtained in the sheet forming process. The sheet 10 has regions with different air permeability in a plan view. Specifically, the sheet 10 has a high air permeability region R1 with relatively high air permeability and a low air permeability region R2 with relatively low air permeability. Air flow resistance can be used as an index of air permeability. In this embodiment, the low air permeability region R2 is a region with an air permeability resistance of 0.2 kPa·s / m or more. The air permeability resistance can be measured by the following method. <Method of measuring airflow resistance> The airflow resistance is measured using a breathability tester (KES-F8 manufactured by Kato Tech Co., Ltd.). Specifically, the sheet is fixed so that the area to be measured in the sheet blocks the air holes of the airflow tester, and the airflow resistance is measured at 23° C. and 53% RH so that the area of ​​the air holes is 2π cm 2 The airflow resistance is measured under the condition of a piston speed of 2 cm / s. This measurement is carried out 10 times, and the average value is taken as the airflow resistance. If the airflow resistance value changes in a small area or the area of ​​the measurement location is small, the hole area of ​​the tester may be reduced, for example, to a value of 0.2π cm2 for the airflow area. 2 Measured at.

[0012] The sheet 10 includes a fiber layer made of fibers. In this embodiment, the sheet 10 is a laminated sheet having a first sheet 11 and a second sheet 12 arranged on one side of the first sheet 11, and both the first sheet 11 and the second sheet 12 are fiber layers. The second sheet 12 extends from the periphery of the first sheet 11, and the sheet 10 has a portion where the first sheet 11 and the second sheet 12 are laminated, and a portion consisting of only the second sheet 12. By making the average fiber diameter of the first sheet 11 smaller than that of the second sheet 12, the breathability of the first sheet 11 becomes lower than that of the second sheet 12.

[0013] In the sheet 10 of this embodiment, the air permeability is partially different in the portion where the first sheet 11 and the second sheet 12 are laminated, thereby forming a low air permeability region R2 and a high air permeability region R1. In the sheet 10, as shown in Figs. 2 to 5, the second sheet 12 has a constant thickness, while the thickness of the first sheet 11 gradually increases from its peripheral edge 17 toward the inside. In the sheet 10, the thickness of the first sheet 11 changes from its peripheral edge 17 toward the inside, thereby partially differentiating the air permeability in the portion where the first sheet 11 and the second sheet 12 are laminated. Specifically, in the sheet 10, the air permeability decreases from its peripheral edge toward the inside. In this embodiment, the low-air-permeability region R2 is a region including the thickest part of the sheet 10, as shown in Fig. 5. The low-air-permeability region R2 includes an inner region M, which will be described later. The high-air-permeability region R1 is disposed so as to surround the low-air-permeability region R2, as shown in Fig. 5.

[0014] In this embodiment, as described above, the first sheet 11 has a partially different airflow resistance, but instead, a sheet having a constant airflow resistance may be used as the first sheet 11. When the first sheet 11 and the second sheet 12 have a constant airflow resistance, it is preferable that either the first sheet 11 or the second sheet 12 extends from the periphery of the other. When the first sheet 11 and the second sheet 12 each have a constant airflow resistance and one of them extends from the periphery of the other, the portion where the two are laminated may be the low-air-permeability region R2, and the portion consisting of only one of the sheets may be the high-air-permeability region R1.

[0015] In the sheet forming process, the sheet 10 is cut out from the raw material sheet 10A. The sheet forming process is performed in the sheet forming section 30. The raw material sheet 10A is a laminated sheet in which the first sheet 11 is laminated on a continuous body of the second sheet 12 (hereinafter also referred to as the "second sheet continuous body") 12A. In this embodiment, the raw material sheet 10A is a laminated sheet in which the first sheet 11 is laminated at a plurality of locations on the second sheet continuous body 12A. The sheet forming process includes a cutting process in which the raw material sheet 10A is cut along the periphery of the first sheet 11 to cut out the sheet 10. The spun shape and the contour shape may be different. The sheet forming section 30 includes a cutting device 31, and in the manufacturing apparatus 100, the raw material sheet 10A is cut by the cutting device 31 to cut out the sheet 10. As the cutting device 31, various known cutting means can be used, for example, a cylindrical or disk-shaped cutter having an annular blade on the circumferential surface or edge, a laser cutter, a high-pressure water jet cutter, a Thomson blade, a heat cutter, an ultrasonic cutter, a feather cutter, etc. In the manufacturing apparatus 100, the cutting device 31 is a laser cutter, and in the sheet forming step according to this embodiment, the raw material sheet 10A is cut using the laser cutter. In this embodiment, after the raw material sheet 10A is cut along the edge of the first sheet 11, the portion of the raw material sheet 10A other than the cut-out sheet 10 is removed.

[0016] In the transfer step, the sheet 10 obtained in the sheet forming step is transferred. The transfer step is performed in the transfer section 40. In the transfer step, first, the suction pad 42 connected to the suction device 41 is suctioned to the low-permeability region R2 of the sheet 10 to hold the sheet 10. Then, the held sheet 10 is moved to the transfer destination. In this embodiment, the destination of the sheet 10 is an area where the subsequent processing step is performed, that is, the processing section 50. In the processing step, both sides of the sheet 10 are covered with covering sheets 71 and 72, but in the transfer step of this embodiment, the sheet 10 is moved onto the covering sheet 72 that covers one side of the sheet 10 in the subsequent processing step.

[0017] In the processing step, both sides of the sheet 10 moved in the transferring step are covered with cover sheets 71, 72. Next, the cover sheets 71, 72 covering the sheet 10 are joined together to form a joint 73. The joint 73 is formed so as to surround the sheet 10 disposed between the sheets 71, 72. Then, the cover sheets 71, 72 with the joint 73 formed therein are cut to obtain individual sheet-like articles 1. As a means for forming the joint 73, various known methods can be used. For example, the cover sheets 71, 72 may be bonded together with an adhesive, or the cover sheets 71, 72 may be fused together with heat, ultrasound, or the like, or may be welded together with high frequency or laser light. As a means for cutting the cover sheets 71 and 72 having the joint portion 73 formed thereon, various known cutting means can be used, and the same cutting device as the cutting device 31 can be used.

[0018] According to the manufacturing method of the sheet-like article of this embodiment, in the transfer step, the suction pad 42 is caused to suction the low-breathability region R2 to hold the sheet 10, and the held sheet 10 is moved to the destination, so that the sheet 10 can be transferred while reducing suction marks on the sheet 10. This point will be described in detail below. The sheet 10 has a high-breathability region R1 and a low-breathability region R2, and the low-breathability region R2 requires a weaker suction force to cause the suction pad 42 to suction and hold the sheet 10 than the high-breathability region R1. In the transfer step of this embodiment, the sheet 10 can be held by a weaker suction force, so that when the sheet 10 is held and transferred, suction marks on the sheet 10 can be reduced, and preferably completely prevented. Therefore, according to this embodiment, the sheet 10 can be transferred while maintaining the quality of the sheet 10.

[0019] It is possible to hold the sheet 10 by making the suction pad 42 adhere to the high-breathability region R1 by increasing the suction force, or to make the suction pad 42 adhere to the sheet 10 without distinguishing between the high-breathability region R1 and the low-breathability region R2. However, when the suction force is increased, more energy is required to hold the suction sheet 10. Furthermore, when the suction force is high, when the suction pad 42 overlaps a part of the low-breathability region R2, the low-breathability region R2 is likely to be marked by suction or to be torn or peeled off. On the other hand, in order to reliably avoid overlapping with the low-breathability region R2, restrictions are likely to be imposed on the shape and formation position of the first sheet 11 portion. According to this embodiment, since the suction pad 42 is attached to the low-breathability region R2, the sheet 10 can be sufficiently held even with a weak suction force, and the sheet 10 can be transferred with less energy.

[0020] In this embodiment, one suction pad 42 may be adsorbed to the low-air-permeability region R2, or multiple suction pads 42 may be adsorbed to the low-air-permeability region R2. Fig. 8 shows an example of the case where one suction pad 42 is adsorbed to the low-air-permeability region R2, and Fig. 9 shows an example of the case where multiple suction pads 42 are adsorbed to the low-air-permeability region R2. From the viewpoint of reliably holding the sheet 10 in the transfer step, the number of suction pads 42 that are to be adsorbed to the low-permeability region R2 of each sheet 10 depends on the size of the sheet, but is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more. Furthermore, when the suction device 41 has a plurality of suction pads 42, the plurality of suction pads 42 may include a suction pad that is not adsorbed to the low-permeability region R2.

[0021] From the viewpoint of preventing suction marks from being left and from the viewpoint of energy saving, in the transfer step, the vacuum pressure of the portion of the sheet 10 to which the suction pad 42 is attached is set to 0.05 mm. -The vacuum pressure is preferably 40 kPa or more, and more preferably -20 kPa or more. The upper limit of the vacuum pressure is not particularly limited as long as the sheet 10 can be adsorbed and held, but is preferably -0.2 kPa or less, for example. The vacuum pressure can be measured by the same method as described later in <Method of measuring vacuum pressure>.

[0022] In this embodiment, when the suction pad 42 is adsorbed to the low-breathability region R2, only a part of the surface of the suction pad 42 facing the sheet 10 may be in contact with the low-breathability region R2. From the viewpoint of reliably adsorbing the suction pad 42 to the low-breathability region R2 and reliably holding the sheet 10, the ratio E1 / E of the area E1 of the portion in contact with the low-breathability region R2 to the total area E of the surface of the suction pad 42 facing the sheet 10 is preferably 0.5 or more, more preferably 0.6 or more, and even more preferably 0.7 or more. It is most preferable that the entire surface of the suction pad 42 facing the sheet 10 is in contact with the low-breathability region R2. The lower limit of the ratio E1 / E can be, for example, 0.3.

[0023] When a plurality of suction pads 42 are adsorbed to the low-breathability region R2, the proportion of the suction pads 42 whose ratio E1 / E value falls within the above-mentioned preferred range is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more. It is most preferable that all of the plurality of suction pads 42 have the ratio E1 / E value within the above-mentioned preferred range. The lower limit of the proportion of the suction pads 42 whose ratio E1 / E value falls within the above-mentioned preferred range can be, for example, 40%.

[0024] In order to ensure that the suction pad 42 is reliably adsorbed to the low-breathability region R2 and that the sheet 10 is reliably held, the ratio E2 / E1 of the airflow resistance E1 of the high-breathability region R1 to the airflow resistance E2 of the low-breathability region R2 is preferably 2 or more, more preferably 2.5 or more, and even more preferably 3 or more. From the viewpoint of ensuring breathability while facilitating adsorption, the ratio E2 / E1 is preferably 2500 or less, more preferably 1000 or less, and even more preferably 250 or less.

[0025] The airflow resistance E2 of the low-air-permeability region R2 is preferably 25 kPa·s / m or less, and more preferably 10 kPa·s / m or less, from the viewpoint of preventing suction marks from being formed and from the viewpoint of energy saving. From the viewpoint of reliably holding the sheet, the airflow resistance E2 of the low-air-permeability region R2 is preferably 0.2 kPa·s / m or more, more preferably 0.4 kPa·s / m or more, and even more preferably 0.6 kPa·s / m or more.

[0026] On the premise that the airflow resistance E1 of the highly air-permeable region R1 is lower than the airflow resistance E2 of the poorly air-permeable region R2, in reality, it is preferably 0.3 kPa·s / m or less, and more preferably 0.2 kPa·s / m or less. From the viewpoint of a realistic value that provides breathability, the airflow resistance E1 of the highly air-permeable region R1 is preferably 0.01 kPa·s / m or more, and more preferably 0.1 kPa·s / m or more.

[0027] The sheet forming process of this embodiment includes a lamination process for forming a raw material sheet 10A, which is a laminated sheet. In the lamination process, the fibers constituting the first sheet 11 are deposited on the continuous body 12A of the second sheet 12 to form the raw material sheet 10A, which is a laminated sheet. In this embodiment, the fibers constituting the first sheet 11 are deposited unevenly on the second sheet continuous body 12A. In other words, the fibers constituting the first sheet 11 are partially deposited on the second sheet continuous body 12A. In the sheet forming process of this embodiment, the sheet 10 is cut out from the raw material sheet 10A, which is a laminated sheet, and the obtained sheet 10 is also a laminated sheet in which the first sheet 11 and the second sheet 12 are laminated, as described above. In the transfer step of this embodiment, the suction pad 42 is adsorbed to the low-breathability region R2, which is the region where the first sheet 11 and the second sheet 12 are laminated, so that when the sheet 10 is held by the suction pad 42, the suction force of the suction pad 42 is applied to both the first sheet 11 and the second sheet 12. Therefore, peeling between the first sheet 11 and the second sheet 12 can be suppressed, and even if the sheet 10 is a laminated sheet, the sheet 10 can be transferred to the destination while maintaining the quality of the sheet 10.

[0028] In the transfer process, the suction pad 42 may be attached to either the surface of the sheet 10 facing the first sheet 11 or the surface of the sheet 10 facing the second sheet 12. However, since the first sheet 11 is formed on the second sheet 12, from the standpoint of manufacturing efficiency, it is preferable to attach the suction pad 42 to the surface of the sheet 10 facing the first sheet 11.

[0029] Examples of methods for forming the first sheet 11 on the continuum 12A of the second sheet 12 include spinning methods such as electrospinning, airlaid, spunbonding, and meltblown. With such spinning methods, it is not necessarily easy to maintain a constant shape and formation position of the first sheet 11 formed by spinning, but the great advantage is that the suction position of the suction pad 42 can be controlled based on the cutting position of the sheet 10, as described below. The method for forming the first sheet 11, which is a fiber layer, on the second sheet 12 does not necessarily require spinning, and a fiber layer produced separately by any method may be placed on the second sheet 12. For example, a fiber web or nonwoven fabric produced by various known methods, such as a fiber web formed by a carding method, may be placed.

[0030] In this embodiment, the sheet forming section 30 of the manufacturing apparatus 100 has an electrospinning device 32 as shown in FIG. 1, and the fibers constituting the first sheet 11 are deposited on the second sheet 12 by the electrospinning method. The electrospinning device 32 has a nozzle 33 that discharges the raw material liquid, a counter electrode 34 that generates an electric field between the nozzle 33, and a moving mechanism 35 that moves the nozzle 33. The raw material liquid means a solution or dispersion of the raw material resin of the constituent fibers of the first sheet 11. The nozzle 33 and the counter electrode 34 are arranged so as to face each other with the second sheet 12 sandwiched therebetween. In this embodiment, the raw material liquid is supplied to the nozzle 33 under a state in which an electric field is generated between the nozzle 33 and the counter electrode 34, and the raw material liquid is discharged from the nozzle 33. At this time, the electrospinning device 32 discharges the raw material liquid while moving the nozzle 33 in the horizontal direction by the moving mechanism 35. The discharged raw material liquid is spun so as to be attracted to the counter electrode 34 while forming nanofibers F through repeated electrical repulsion and evaporation of the solvent contained in the raw material liquid. These nanofibers F are the constituent fibers of the first sheet 11. The nanofibers F are deposited on the second sheet 12 to form a deposit of nanofibers. This deposit becomes the first sheet 11.

[0031] In this specification, nanofibers generally have a diameter of 10 nm to 3000 nm, particularly 10 nm to 1000 nm, when the diameter is expressed as an equivalent circle diameter. The thickness of nanofibers can be measured, for example, by observing the fibers at a magnification of 10,000 times using a scanning electron microscope, arbitrarily selecting 10 fibers from the two-dimensional image excluding defects (lumps of nanofibers, intersections of nanofibers, polymer droplets), drawing a line perpendicular to the longitudinal direction of the fibers, and directly reading the fiber diameter.

[0032] In this embodiment, the sheet forming process includes a detection process for detecting the position of the low-permeability region R2 in the raw material sheet 10A, and a cutting position correction process for correcting the cutting position of the raw material sheet 10A. The detection process and the cutting position correction process are performed before the cutting process for cutting the sheet 10 from the raw material sheet 10A.

[0033] The detection process is performed after the lamination process. In the detection process, the surface of the raw material sheet 10A on which the first sheet 11 is arranged is imaged, and the position of the low-permeability region R2 is detected using the obtained image. In the manufacturing apparatus 100, as shown in FIG. 1, a camera (hereinafter also referred to as the "first camera") 51 is arranged between the electrospinning device 32 and the cutting device 31, and the raw material sheet 10 is imaged by the first camera 51. Then, the position of the low-permeability region R2 is detected by performing image processing on the image captured by the first camera 51. For example, the image captured by the first camera 51 is binarized using a threshold value that can distinguish the low-permeability region R2 from other regions, and the low-permeability region R2 can be detected.

[0034] In the cutting position correction step, the cutting position of the raw material sheet 10A is corrected based on the position of the low-permeability region R2 detected in the detection step. Specifically, the cutting position is corrected so that when the raw material sheet 10A is cut in the cutting step, the high-permeability region R1 of the cut-out sheet 10 is disposed along the entire periphery of the sheet 10. For example, if the detected low-permeability region R2 overlaps with the cutting position C1 (see FIG. 6(a)), the cutting position C1 is corrected so that the low-permeability region R2 is positioned within the region surrounded by the cutting position C1 (see FIG. 6(b)). The cutting step is performed after the cutting position correction step. In the cutting step, the raw material sheet 10A is cut to cut out the sheet 10 having a desired shape.

[0035] In the transfer step of this embodiment, it is preferable to determine the position of the suction pad 42 on the sheet 10 based on the cutting position of the raw material sheet 10A. The cutting position of the raw material sheet 10A, i.e., the cutting position of the laminated sheet, may be the actual cutting position in the cutting step, or may be the planned cutting position calculated in the cutting position correction step. In cases such as when the first sheet 11 is formed by a spinning method, it may be difficult to maintain the shape and formation position of the first sheet 11 constant with high precision. By controlling the suction position of the suction pad 42 based on the cutting position rather than the arrangement position of the first sheet 11, the suction pad 42 can be suctioned with high precision based on the contour shape of the sheet 10 even if the position where the constituent fibers of the first sheet 11 are deposited is shifted from the planned formation position of the low-permeability region R2.

[0036] In the transfer step, it is also preferable to detect the outer shape of the sheet 10 cut out in the cutting step, and determine the position of the sheet 10 at which the suction pad 42 is to be adsorbed based on the detected outer shape of the sheet 10. In this embodiment, after the sheet 10 is cut out from the raw sheet 10A, the portion of the raw sheet 10A other than the cut-out sheet 10 is removed. When removing the portion of the raw sheet 10A other than the cut-out sheet 10, the position of the sheet 10 to be conveyed may be shifted. In the transfer step, the outer shape of the sheet 10 is detected, and the position of the suction pad 42 is determined based on the detected outer shape of the sheet 10. This makes it possible to reliably adsorb the suction pad 42 to the low-permeability region R2 even if the position of the cut-out sheet 10 is shifted when the cut-out sheet 10 is conveyed.

[0037] In this embodiment, the surface of the cut-out sheet 10 on which the first sheet 11 is disposed is imaged, and the obtained image is used to detect the outline of the sheet 10. In the manufacturing apparatus 100, as shown in FIG. 1, a camera (hereinafter also referred to as the "second camera") 52 is disposed between the cutting device 31 and the suction device 41, and the second camera 52 images the sheet 10. Then, the outline of the sheet 10 is detected by performing image processing on the image captured by the second camera 52. For example, the image captured by the second camera 52 is binarized using a threshold value that can distinguish between the sheet 10 and other areas, and the outline of the sheet 10 can be detected.

[0038] In the transfer step of this embodiment, the position on the sheet 10 where the suction pad 42 is to be suctioned may be determined based on the position of the low-air-permeability region R2 detected in the detection step. By doing so, even if the position where the constituent fibers of the first sheet 11 are deposited in the lamination step is shifted from the planned formation position of the low-air-permeability region R2, the suction pad 42 can be reliably suctioned to the low-air-permeability region R2.

[0039] In this embodiment, in the cutting step, the cutting position of the raw material sheet 10A is determined based on the position of the low-permeability region R2 detected in the detection step, and in the transferring step, the position on the sheet 10 where the suction pad 42 is to be suctioned may also be determined based on the position of the low-permeability region R2 detected in the detection step. By doing so, even if the position where the constituent fibers of the first sheet 11 are deposited in the laminating step is shifted from the planned position where the low-permeability region R2 is to be formed, the suction pad 42 can be reliably suctioned to the low-permeability region R2.

[0040] Next, the sheet 10 formed in the sheet forming step of this embodiment will be described in detail. As shown in Fig. 3, the first sheet 11 of the sheet 10 has undulations on the surface opposite to the side where the second sheet 12 is located, while the surface facing the second sheet 12 is flat. Hereinafter, the surface of the first sheet 11 opposite to the side where the second sheet 12 is located will be referred to as the first surface S1, and the surface facing the second sheet 12 will be referred to as the second surface S2. As shown in Fig. 4, the first sheet 11 of this embodiment has a structure in which the first surface S1 side is raised inward. Although the first sheet 11 is very thin, for convenience of explanation, the first sheet 11 is drawn very large in Figs. 3 and 4.

[0041] The first sheet 11 has a gradation region G whose thickness gradually increases from its peripheral edge 17 inward. The gradation region G is a region that rises inward from the peripheral edge 17 and includes the peripheral edge 17 of the first sheet 11. When the first surface S1 of the first sheet 11 is viewed in plan, the gradation region G is a region that inclines toward the inner region M in a cross section taken along an orthogonal line perpendicular to the center line CL of the outline of the inner region M (see FIG. 3). The cross section taken along the orthogonal line is, for example, a cross section taken along line III-III in FIG. 2. Such a cross section is determined based on the three-dimensional shape data described above. A method for identifying the gradation region will be described in detail below.

[0042] [How to specify the gradation area] First, the three-dimensional shape of the surface of the first side S1 of the first sheet 11 is measured by using a laser-type three-dimensional shape measuring system (for example, a combination of a measuring system EMS2002AD-3D manufactured by COMS Co., Ltd. and a displacement sensor LK-2000 manufactured by Keyence Corporation). Specifically, the second sheet 12 is placed on an autostage and the sheet 10 is set. Next, while moving the autostage in the X-axis direction, a laser displacement meter is scanned to measure the surface height of the first side S1 of the first sheet 11 at a predetermined measurement pitch XP. Then, the autostage is shifted in the Y-axis direction perpendicular to the X-axis by the measurement pitch YP, and while moving the autostage in the X-axis direction, a laser displacement meter is scanned to measure the surface height of the first side S1 of the first sheet 11 at the predetermined measurement pitch XP. By repeating this operation, surface shape data of the first side S1 of the first sheet 11 is obtained. The measurement pitch in the X-axis direction is 0.235 mm, the measurement pitch YP in the Y-axis direction is 0.350 mm, and the resolution in the height (Z-axis) direction is 0.1 μm. The measurement range is a range that includes the entire first sheet 11 in a plan view, i.e., in the X-axis and Y-axis directions, and the measurement pitch may be changed appropriately depending on the object. The above measurements are performed under no load. In this manner, the three-dimensional shape data of the first sheet 11 is measured. Next, in the three-dimensional shape data, the position where the thickness is maximum is specified as the apex position, and the thickness of the first sheet 11 at the apex position is obtained. Next, based on the three-dimensional shape data, a contour line showing the outline of an area where the thickness is 80% of the thickness at the apex position (hereinafter, also referred to as the "80% thickness contour line") is obtained, and the position of the contour line is reflected in the three-dimensional shape data together with the planar contour curve. For example, as shown in FIG. 7, the planar contour curve C0 and the 80% thickness contour line C80 are reflected in the three-dimensional shape data. Since a nanofiber layer containing nanofibers generally has fibers protruding from the surface and locally has portions with few fibers and portions with many fibers, the 80% thickness contour line may contain noise. In order to remove such noise, an approximation curve process is performed using a polynomial approximation formula. If multiple approximation curves are obtained by this process, the approximation curve closest to the three-dimensional shape data is selected. Next, an arbitrary position on the planar contour curve is set as a first point, and first to tenth points that divide the circumference of the planar contour curve into ten equal parts are set on the planar contour curve. References N1 to N10 shown in FIG. 7 are an example of the first to tenth points. Next, a cross-sectional contour of the first sheet 11 in the three-dimensional shape data is obtained at each of the first to tenth points. The cross-sectional contour is a contour of a cross section when the first sheet of the three-dimensional shape data is cut along a line segment that connects each of the first to tenth points on the planar contour curve and the 80% contour line at the shortest distance in a plan view. Next, the cross-sectional contour at each of the first to tenth points is subjected to the above-mentioned approximation curve processing to obtain a cross-sectional contour curve. Next, the positions of the first to tenth points corresponding to each of the obtained cross-sectional contour curves are reflected on the cross-sectional contour curves, and the positions of the peripheral ends of the first sheet 11 on the cross-sectional contour curve are specified. Next, in each of the obtained cross-sectional contour curves, a region in which the thickness gradually increases from the peripheral edge toward the inside of the first sheet 11 and the width of the inclined region is specified as 3 mm or more. The width is the length from the peripheral edge to the apex position in the cross-sectional contour curve, or the length from the peripheral edge to the maximum thickness portion described later. In addition, examples of a pattern in which the thickness gradually increases in the cross-sectional contour curve include a pattern in which the thickness increases linearly, a pattern in which the thickness increases curvedly such as a sigmoid curve or an exponential curve, and a pattern in which the thickness increases in multiple stages. Then, the number of points at which the cross-sectional contour curve having the inclined region is confirmed among the first to tenth points is counted. When the number of points of the cross-sectional contour curve having the measured inclined region is "n", the ratio (%) of the number of cross-sectional contour curves having the inclined region to the total of 10 points of the first to tenth points can be calculated by "(n / 10)×100(%)". In other words, it can be determined what percentage of the entire peripheral length of the first sheet is made up of gradation regions. For example, if cross-sectional contour curves having the above-mentioned inclined region are confirmed at five of the first through tenth points, the first sheet being measured can be determined to have a gradation region that accounts for 50% of the entire peripheral length of the first sheet.

[0043] The first sheet 11 in this embodiment has the gradation region G and an inner region M surrounded by the gradation region G. As shown in FIG. 3, the thickness of the gradation region G of the first sheet 11 in this embodiment gradually increases in one direction, whereas the thickness of the inner region M is substantially constant. Therefore, the thickness of the inner region M is allowed to vary slightly depending on the position. For example, the thickness is allowed to vary within a range of about ±25% of the average thickness. In this embodiment, the thickness of the inner region M is the same as the thickness D1 (see FIG. 3) of the maximum thickness part 15 of the gradation region G. The maximum thickness part 15 of the gradation region G is the part where the thickness of the gradation region G is maximum, and is the end of the gradation region G on the inner region M side. The thickness of the inner region M is preferably 80% or more, more preferably 90% or more, of the thickness at the apex position of the first sheet 11. The inner region M can be specified based on the above-mentioned cross-sectional contour curve. The first sheet 11 may have a gradation region G and an inner region M as in this embodiment, or it may have only a gradation region between the peripheral edge and the apex position without having an inner region.

[0044] In this embodiment, in the transfer step, the suction pad 42 is adsorbed to the low-permeability region R2 of the sheet 10, but the suction pad 42 may be adsorbed to the gradation region G in the low-permeability region R2 or may be adsorbed to the inner region M in the low-permeability region R2. From the viewpoint of reliably adsorbing the suction pad 42 to the low-permeability region R2, it is preferable that the suction pad 42 is adsorbed to the inner region M in the low-permeability region R2. Note that the suction pad 42 may be adsorbed so as to straddle the gradation region G and the inner region M in the low-permeability region R2.

[0045] The high-breathability region R1 and the low-breathability region R2 of the sheet 10 may have the same color or different colors. In this specification, the term "color" includes both chromatic and achromatic colors, and also includes fluorescent colors and colors with metallic luster. The term "different colors" includes differences in at least one of hue, brightness, saturation, transparency, etc. By making the color of the first sheet 11 different from the color of the second sheet 12, the color of the high-breathability region R1 can be made different from the color of the low-breathability region R2. Since the high-permeability region R1 and the low-permeability region R2 are different in color, the low-permeability region R2 can be easily recognized during the transfer process, so that the suction pad 42 can be easily adsorbed to the low-permeability region R2.

[0046] In the sheet 10, the area K1 of the high-breathability region R1 and the area K2 of the low-breathability region R2 in a plan view may be the same or different. When the area K1 of the high-breathability region R1 and the area K2 of the low-breathability region R2 are different, either one of them may be larger. From the viewpoint of reliably adsorbing the suction pad 42 to the low-breathability region R2, it is preferable that the area K1 of the high-breathability region R1 is smaller than the area K2 of the low-breathability region R2. Here, the area K2 of the low-breathability region R2 means the area of ​​the inner region M in the low-breathability region R2, and does not include the area of ​​the gradation region G.

[0047] From the viewpoint of reliably adsorbing the suction pad 42 to the low-breathability region R2, the ratio K2 / K of the area K2 of the low-breathability region R2 to the area K of the sheet 10 is preferably 0.35 or more, more preferably 0.4 or more, and even more preferably 0.45 or more, and from the viewpoint of forming a gradation region G, it is preferably less than 1, more preferably 0.9 or less, and even more preferably 0.8 or less.

[0048] The fibers constituting the first sheet 11 of the sheet 10 may include nanofibers, beads, etc., containing a polymeric compound capable of forming fibers. The polymeric compound may be a water-insoluble polymeric compound. Examples of water-insoluble polymeric compounds include fully saponified polyvinyl alcohol that can be insolubilized after nanofiber formation, partially saponified polyvinyl alcohol that can be crosslinked after nanofiber formation by using a crosslinking agent in combination, oxazoline-modified silicone such as poly(N-propanoylethyleneimine) graft-dimethylsiloxane / γ-aminopropylmethylsiloxane copolymer, zein (a major component of corn protein), polyester resins such as polylactic acid (PLA), polyethylene terephthalate resin, and polybutylene terephthalate resin, acrylic resins such as polyacrylonitrile resin and polymethacrylic acid resin, polystyrene resin, polyvinyl butyral resin, polyurethane resin, polyamide resins such as nylon, polyimide resin, and polyamideimide resin. These water-insoluble polymeric compounds may be used alone or in combination of two or more.

[0049] The fibers constituting the first sheet 11 of the sheet 10 may contain nanofibers of a water-soluble polymer compound. Examples of the water-soluble polymer compound include mucopolysaccharides such as pullulan, hyaluronic acid, chondroitin sulfate, poly-γ-glutamic acid, modified corn starch, β-glucan, glucooligosaccharide, heparin, and keratosulfate, cellulose, pectin, xylan, lignin, glucomannan, galacturon, psyllium seed gum, tamarind seed gum, gum arabic, tragacanth gum, soybean water-soluble polysaccharide, alginic acid, carrageenan, laminaran, agar (agarose), fucoidan, methylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose, and synthetic polymers such as partially saponified polyvinyl alcohol (when not used in combination with a crosslinking agent), low-saponified polyvinyl alcohol, polyvinylpyrrolidone (PVP), polyethylene oxide, water-soluble nylon, water-soluble polyester, and sodium polyacrylate. These water-soluble polymer compounds may be used alone or in combination of two or more.

[0050] The second sheet 12 is a layer capable of maintaining the shape of the sheet 10, and may be a single layer or multiple layers. As the second sheet 12, a fiber sheet such as a nonwoven fabric can be used. From the viewpoint of adsorbing the suction pad 42 to the sheet 10 while maintaining its quality, the second sheet 12 is preferably breathable. As the breathable second sheet 12, a fiber sheet or a sponge is preferably used. Specifically, the fiber sheet is various nonwoven fabrics, woven fabrics, knitted fabrics, paper, mesh sheets, and laminates thereof. As the nonwoven fabric, for example, a meltblown nonwoven fabric, a spunbond nonwoven fabric, an air-through nonwoven fabric, and a spunlace nonwoven fabric can be used, but is not limited to these. The fibers or strands constituting these nonwoven fabrics and mesh sheets may be in the nanofiber category or may be thicker than that. In addition, as the fibers, fibers made of fiber-forming synthetic resins and natural cellulose fibers such as cotton and pulp can be used. Specifically, the sponge is made of a porous material obtained by foaming synthetic resin or natural resin, for example, foamed resin. Examples of the synthetic or natural resin that can be used include, but are not limited to, urethane, polyethylene, melamine, natural rubber, chloroprene rubber, ethylene propylene rubber, nitrile rubber, silicone rubber, fluororubber, etc. As the foamed resin, various materials can be used as long as they can be formed into a breathable form. In this specification, the quality of the transferred sheet means that, in the case where the sheet is a laminate, the laminate is not peeled off. Also, it is preferable that the sheet does not have any suction marks.

[0051] Although the present invention has been described based on the preferred embodiments thereof, the present invention is not limited to the above-mentioned embodiments. For example, in the present embodiment, the sheet 10 having a desired shape is cut out from the raw material sheet 10A in the sheet forming step, but instead, a sheet having a desired shape may be formed in the sheet forming step. When a sheet having a desired shape is formed in the sheet forming step, the formed sheet may have a multi-layer structure or a single-layer structure.

[0052] In this embodiment, the fibers constituting the first sheet 11 are deposited on the continuous body 12A of the second sheet 12, but alternatively, the fibers constituting the first sheet 11 may be deposited on the second sheet 12 that has been cut to a predetermined shape. Also, in this embodiment, the sheet 10 is multi-layered, but instead, the sheet 10 may be a single layer.

[0053] The planar shape of the sheet 10 is not particularly limited, and may be, for example, a circle (see FIG. 10(a)), a triangle (see FIG. 10(b)), a star, a polygon, an ellipse, a curved shape, or the like.

[0054] Although the manufacturing method of this embodiment includes a processing step, it does not have to include a processing step. For example, the sheet 10 obtained in the sheet forming step may be made into a sheet-like article. Detection of the position of the low-air-permeability region in the detection step, detection of the outline of the cut-out sheet 10 in the transfer step, etc. may be performed by a method other than image processing. EXAMPLES

[0055] The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited to such examples. Unless otherwise specified, "%" means "% by mass".

[0056] Example 1 As in the manufacturing method of the sheet-like article of this embodiment, a sheet having a low-air-permeability region and a high-air-permeability region was formed, and the sheet was held by adsorbing a suction pad to the low-air-permeability region of the sheet, and then transferred to a destination. The specifications of the formed sheet, the vacuum pressure, and the pressure difference per suction pad are as shown in Table 1.

[0057] [Table 1]

[0058] <How to measure vacuum pressure> Compressed air was supplied from the air pressure source to a vacuum ejector connected to a suction pad (manufactured by SMC Corporation, model number: ZP3P-T20JT2SF-WM-A16-B01), creating a vacuum inside the suction pad. A regulator (manufactured by SMC Corporation, model number: ARG40-02G2H) was placed between the air pressure source and the vacuum ejector. The vacuum pressure inside the suction pad in the vacuum state was then measured using a pressure sensor (manufactured by SMC Corporation, model number: ZSF20-NM-01-LDK). The measurement was performed 10 times, and the average value was taken as the vacuum pressure. The vacuum ejectors used in Examples 1 to 3 and Comparative Examples 1 and 2 are as follows. Examples 1 to 3, Comparative Example 1: SMC Corporation, Model No.: ZH05DLA Comparative Example 2: SMC Corporation, Model No. ZH20DLA

[0059] <How to measure the pressure difference per suction pad> The pressure difference ΔP (kPa) was calculated by the following formula (1): In formula (1), A is the airflow resistance (KPa), L is the leakage rate (L / min), and S' is the effective suction area of ​​the suction pad (cm 2 ).

[0060]

number

[0061] The leakage amount L was calculated from the exhaust characteristics and flow rate characteristics of the vacuum ejector as follows. For example, in the case of Example 1, the relationship between the leakage amount L (L / min) and the vacuum pressure X (kPa) is shown by creating a calibration curve from the catalog as follows. L=X / 2+14

[0062] The effective suction area S' of the suction pad was calculated by the following formula (2). In formula (2), S is the area (cm 2 ).

[0063]

number

[0064] S is the surface area of ​​the suction pad facing the sheet (cm 2 ) was calculated by the following formula (3): In formula (3), D is the diameter of the surface of the suction pad facing the sheet, and is 20 cm.

[0065]

number

[0066] Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated according to the following evaluation criteria. [Evaluation Criteria] A: The sheet can be adsorbed and transferred to the destination. There are no adsorption marks on the transferred sheet. B: The sheet can be adsorbed and transferred to the destination. There are some adsorption marks on the sheet after transfer. C: The sheet can be adsorbed and transferred to the destination. After the sheet is transferred, there will be adsorption marks. D: The sheet can be adsorbed and transferred to the destination. After the sheet is transferred, the first sheet and the second sheet are peeled off. E: Unable to grasp the sheet and transfer it to the destination.

[0067] As shown in Table 1, in Comparative Example 1, the sheet could not be grasped and transferred to the destination. In Comparative Example 2, the sheet could be grasped and transferred to the destination, but the first sheet and the second sheet were peeled off after the transfer, and the quality of the sheet could not be maintained. In all of Examples 1 to 3, the sheet could be grasped and transferred to the destination. In Example 1, there were no suction marks on the sheet after the transfer, and the sheet could be transferred while maintaining its quality. In Examples 2 and 3, there were suction marks on the sheet after the transfer, but the suction marks were slight, and the sheet could be transferred while maintaining its quality. Therefore, it can be seen that the method for producing a sheet-like article of the present invention allows the sheet to be moved to the destination while maintaining its quality. [Explanation of symbols]

[0068] 1 Sheet-like items 10 Sheets 100 Sheet-like article manufacturing device 30 Sheet forming section 40 Transfer section 41 Suction device 42 Suction pad

Claims

1. A method for producing a sheet-like article, comprising: a sheet forming step of forming a sheet having a desired shape or cutting a sheet having a desired shape from a raw material sheet; a transfer step of transferring the sheet obtained in the sheet forming step, In the sheet forming step, a sheet having a high-air-permeability region having relatively high air permeability and a low-air-permeability region having relatively low air permeability in a plan view is formed, In the transfer step, a suction pad connected to a suction device is attached to the low-permeability region to hold the sheet, and the sheet is then moved to a destination.

2. the sheet is a laminated sheet having a first sheet and a second sheet disposed on one surface side of the first sheet, 2. The method for producing a sheet-like article according to claim 1, wherein in the sheet forming step, the sheet having the low-breathability region and the high-breathability region is formed by unevenly depositing fibers constituting the first sheet on the second sheet.

3. The sheet forming step includes: a lamination step of depositing fibers constituting the first sheet on the continuous body of the second sheet to form a laminated sheet in which the first sheet is laminated on the continuous body of the second sheet; a detection step of detecting the position of the low-permeability region in the laminated sheet after the lamination step; a cutting position correcting step of correcting a cutting position of the laminated sheet based on the position of the low-permeability region detected in the detecting step; a cutting step of cutting the laminated sheet after the cutting position correction step, and cutting out the sheet having a desired shape in a plan view, The method for producing a sheet-like article according to claim 2 , wherein in the transferring step, a position on the sheet where the suction pad is to be sucked is controlled based on a cutting position of the laminated sheet.

4. 4. The method for manufacturing a sheet-like article according to claim 3, wherein in the transfer step, the outer shape of the sheet cut out in the cutting step is detected, and the position on the sheet at which the suction pad is to be adsorbed is determined based on the detected outer shape of the sheet.

5. The sheet forming step includes: a lamination step of depositing fibers constituting the first sheet on the continuous body of the second sheet to form a laminated sheet in which the first sheet is laminated on the continuous body of the second sheet; a detection step of detecting a position of the low-air-permeability region in the laminated sheet after the laminating step, The method for manufacturing a sheet-like article according to claim 2 , wherein in the transferring step, a position on the sheet where the suction pad is to be suctioned is determined based on the position of the low-permeability region detected in the detecting step.

6. a cutting step of cutting the laminated sheet after the detection step to cut out the sheet having a desired shape in a plan view, The method for producing a sheet-like article according to claim 5 , wherein in the cutting step, a cutting position of the laminated sheet is determined based on the position of the low-permeability region detected in the detecting step.

7. The method for producing a sheet-like article according to any one of claims 1 to 6, wherein the low-breathability region has an airflow resistance of 0.2 kPa·s / m or more and 25 kPa·s / m or less.

8. The method for producing a sheet-like article according to any one of claims 1 to 6, wherein in the transferring step, a vacuum pressure at the portion of the sheet to which the suction pad is attached is -40 kPa or more.

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