JP2023067182A - Composite sheet manufacturing method - Google Patents

Abstract

To provide a composite sheet manufacturing method that enables quality of product including a composite sheet to be improved and stabilized.SOLUTION: A composite sheet manufacturing method comprises: a step to draw a sheet containing elastic material; a sealing step to form a composite sheet by superimposing a stretchable sheet obtained at the step to draw the sheet on the other sheet and sealing points; a constriction and transportation step to constrict the composite sheet so as to be target stretch magnification while transporting the composite sheet in extended state; an image data acquisition step to obtain image data by imaging a surface of the composite sheet constricted at the constriction and transportation step; a pitch measurement step to measure a pitch width of a seal point formed on the composite sheet at the sealing step on the basis of the image data; a constriction state determination step to determine the constriction state of the composite sheet based on the pitch width; and a constriction control step to control the stretch magnification of the composite sheet based on the determination result at the constriction state determination step.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a composite sheet.

Conventionally, techniques for processing a sheet to impart various functions are known. In Patent Document 1, a stretching mechanism provided with a pair of rolls having tooth grooves that mesh with each other on the outer peripheral surface is used, the rolls are rotated to supply a composite sheet to the meshing portions, and the sheet is stretched. A method of manufacturing a stretchable sheet is described.

JP 2011-125638 A

In recent years, a manufacturing method has been known in which a composite sheet is formed by overlapping and joining a sheet stretched by a stretching mechanism as described in Patent Document 1 and another sheet. In addition, there are cases in which the composite sheet is subjected to further processing such as bonding to another sheet in the line for manufacturing the composite sheet. Since the composite sheet is stretched in the production line, it is sometimes required to suitably control the stretched state of the composite sheet in order to improve the processing quality in the post-process. For example, when a composite sheet is joined to another sheet to form a product, by suitably reducing the degree of elongation of the composite sheet and joining it to another sheet, twisting and wrinkling during contraction of the product can be suppressed. , it is possible to improve the quality of product functions and appearance.
However, it is unavoidable that the expansion/contraction ratio of the sheet changes due to variations in the raw material properties of the composite sheet, fluctuations in operation control, or poor rotation of the rolls. Therefore, there is room for improvement in stabilizing the production of products including composite sheets and increasing the quality of composite sheet products.

In view of the above circumstances, the present invention relates to the provision of a composite sheet manufacturing method capable of enhancing and stabilizing the quality of products containing the composite sheet.

The present invention comprises a step of stretching a sheet containing a stretchable material, a sealing step of overlapping the stretchable sheet obtained by the stretching step of the sheet and another sheet and performing point sealing to form a composite sheet, and a sealing step of forming the composite sheet. A contraction conveying step of contracting the composite sheet to a target expansion/contraction ratio while conveying it in a stretched state; an obtaining step, a pitch measuring step of measuring a pitch width of the seal points formed in the composite sheet in the sealing step based on the image data, and a contraction of determining a contracted state of the composite sheet based on the pitch width. A method for manufacturing a composite sheet is provided, comprising: a state determination step; and a shrinkage control step of controlling the expansion/contraction ratio of the composite sheet based on the determination result of the shrinkage state determination step.

According to the manufacturing method of the composite sheet of the present invention, the quality of the product containing the composite sheet can be improved and stabilized.

1 is a schematic diagram showing a configuration example of a composite sheet manufacturing apparatus according to an embodiment; FIG. FIG. 10 is a plan perspective view showing a partially enlarged composite sheet after a contraction-conveying step; It is a block diagram which illustrates the structural example of an inspection apparatus. 4 is a flow chart showing an example of a method for manufacturing a composite sheet according to the embodiment; FIG. 10 is a partially enlarged plan view showing an example of the arrangement of seal points in the captured image of the composite sheet after the shrinking and conveying process; FIG. 6 is an enlarged plan view showing an example of the pitch width of the seal points shown in FIG. 5; FIG. 11 is a partially enlarged plan view showing a state in which an inspection window is attached to the captured image of the composite sheet after the contraction-conveying process;

A preferred embodiment of the method for manufacturing a composite sheet of the present invention will be described below with reference to the drawings as appropriate. However, the present invention is not limited to the forms exemplified below.
In this specification, the machine flow direction and the conveying direction of the manufacturing apparatus at the time of manufacturing the composite sheet are referred to as the MD direction (machine direction), and the width direction (perpendicular direction) orthogonal to the machine flow direction is referred to as the CD direction (cross direction). Say. A direction orthogonal to the MD direction and the CD direction is called an OD direction (Orthogonal Direction). The MD direction, CD direction, and OD direction shown in FIG. 1, which will be described later, are three axial directions orthogonal to each other, and are common in all drawings of this specification.

First, a manufacturing apparatus 100 preferably used in the method of manufacturing a composite sheet of the present invention will be described.
The manufacturing apparatus 100 includes a stretching mechanism 10, a sealing mechanism 20, a shrinking transport mechanism 30, an inspection device 40, and an illumination device 60, as illustrated in FIG.

The stretching mechanism 10 has a first guide roll 11 , a second guide roll 12 and a tooth gap roll 13 . The first guide roll 11 is provided on the upstream side in the MD direction of the tooth groove roll 13 and has a pair of rolls 111 and 112 . The roll 111 is connected to a servomotor (drive source; hereinafter referred to as a first servomotor) (not shown). The roll 111 is rotated by the first servomotor, causing the roll 112 to rotate accordingly. The first guide roll 11 unwinds the sheet A including the elastic material from the original roll R1, supports (nipples) the sheet A before being stretched by the tooth groove rolls 13, and conveys it in the MD direction. Thereby, the first guide roll 11 supplies the sheet A to the tooth groove roll 13 . Note that the MD direction shown in FIG. 1 is the direction in which the sheet A unwound from the original fabric roll R1, the sheet B and the composite sheet AB described later are conveyed, and the CD direction orthogonal to this direction is the direction in which the sheet A, the width direction of the elastic sheet A1, the sheet B, and the composite sheet AB.

The second guide roll 12 is provided downstream in the MD direction from the first guide roll 11 and has a pair of rolls 121 and 122 . The roll 121 is connected to an unillustrated servomotor (hereinafter referred to as a second servomotor). The roll 121 is rotated by the second servomotor, thereby rotating the roll 122 . The second guide roll 12 supports (nipples) the elastic sheet A1 after the sheet A has been stretched by the tooth gap roll 13, pulls it out from the tooth gap roll 13, and conveys it in the MD direction. The second servomotor is configured to rotate the roll 121 at a roll peripheral speed different from the roll peripheral speed of the first guide roll 11 .

The tooth gap roll 13 is provided between the first guide roll 11 and the second guide roll 12 in the MD direction and has a pair of rolls 131 and 132 . The roll 131 is connected to a servomotor (not shown) (hereinafter referred to as a third servomotor). The roll 131 is rotated by the third servomotor, which causes the roll 132 to rotate. The tooth groove roll 13 imparts stretchability to the sheet A supplied to the meshing portions of the rolls 131 and 132 while the rolls 131 and 132 are rotating. Thereby, elastic sheet A1 is formed.

A plurality of teeth T1, T2 and a plurality of tooth grooves are formed on the outer peripheral surface of each of the rolls 131, 132, as illustrated in FIG. A plurality of teeth T1, T2 and a plurality of grooves extend along the axis of rotation of the rolls 131,132. Each of the rolls 131 and 132 rotates with the tooth T1 and the tooth T2 meshing with each other by transmitting the driving force from the third servomotor to the tooth groove roll 131 . The extending direction of the tooth space is not limited to the rotating shaft described above, and may be, for example, the circumferential direction of the roll.

In the stretching mechanism 10 , the supply speed of the sheet A to the tooth groove roll 13 can be controlled by the roll peripheral speed V<b>1 of the first guide roll 11 . The delivery speed of the elastic sheet A1 stretched by the tooth groove roll 13 can be controlled by the roll peripheral speed V2 of the second guide roll 12 . By making the roll peripheral speed V2 of the second guide roll 12 faster than the roll peripheral speed V1 of the first guide roll 11 (V2>V1), it is possible to apply stretching force to the sheet A and the elastic sheet A1. can. That is, the extension force can be controlled by appropriately setting the difference (V2-V1) between the roll peripheral velocities. As a result, between the first guide roll 11 and the second guide roll 12, the sheet A can be appropriately given a stretching force in the MD direction necessary for stretching.

The sealing mechanism 20 has a pattern roll 21 and a sealing point forming device 22 . The pattern roll 21 is a roll that rotates while supporting the stretchable sheet A1 and another sheet B. As shown in FIG. As the pattern roll 21 rotates, the sheet B is unwound from the original fabric roll R2 of the sheet B, and the stretchable sheet A1 stretched by the stretching mechanism 10 is conveyed in the MD direction in a stretched state. . The pattern roll 21 according to the present embodiment is a pattern roll having a plurality of protrusions (not shown) formed on the outer peripheral surface, and each of the plurality of protrusions is pressed against the superimposed sheet in which the elastic sheet A1 and the sheet B are superimposed. be done. Note that the number of other sheets B may be one, or two or more.

The seal point forming device 22 sandwiches the elastic sheet A1 and the sheet B together with the pattern roll 21, and stretches the elastic sheet A1 and the sheet B conveyed in the MD direction by the pattern roll 21 in the MD direction and the CD direction. A plurality of seal points P are formed intermittently at intervals. Specifically, the overlapping sheets of the elastic sheet A1 and the sheet B are pushed up by the protrusions on the peripheral surface of the pattern roll 21, and the seal point forming device 22 joins them from the opposite side, thereby forming a plurality of sheets. is formed (see FIG. 2). The seal points P are joint points between the stretchable sheet A1 and the sheet B, and are provided in plurality at predetermined intervals in the MD direction and the CD direction. In this embodiment, the number of protrusions formed on the pattern roll 21 substantially matches the number of seal points P formed on the composite sheet AB. As a result, the elastic sheet A1 and the sheet B are intermittently joined (point-sealed) in the MD direction and the CD direction to form a composite sheet AB in which the elastic sheet A1 and the sheet B are superimposed. Elastic sheet A1 is joined to sheet B at seal point P in a stretched state. Therefore, between the seal points P in the MD direction, the sheet B is joined with a length corresponding to the length of the elastic sheet A1 in the stretched state. The sealing method by the seal point forming device 22 is not particularly limited, and various commonly used methods can be used. For example, an ultrasonic welding method or the like is adopted. The shape of the seal point is not particularly limited, and various shapes can be used. One pattern roll 21 may have patterns of the same shape, or may have patterns in which various shapes are mixed.

The contraction conveying mechanism 30 is a mechanism for contracting the composite sheet AB on which a plurality of seal points P are formed in the MD direction and conveying it downstream. The contraction conveying mechanism 30 is provided between the sealing mechanism 20 and the inspection device 40 in the MD direction, and has a third guide roll 31 and a fourth guide roll 32 .

The third guide roll 31 is provided upstream in the MD direction from the fourth guide roll 32 and has a pair of rolls 311 and 312 . The roll 311 is connected to a servomotor (not shown) (hereinafter referred to as a fourth servomotor). The roll 311 is rotated by the fourth servomotor, causing the roll 312 to rotate accordingly. The third guide roll 31 supports (nipples) the composite sheet AB and conveys it in the MD direction. The fourth servomotor is configured to rotate the roll 311 at a roll peripheral speed different from the roll peripheral speeds of the pattern roll 21 and the fourth guide roll 32 .

The fourth guide roll 32 is provided downstream in the MD direction from the third guide roll 31 and has a pair of rolls 321 and 322 . The roll 321 is connected to a servomotor (not shown) (hereinafter referred to as a fifth servomotor). The roll 321 is rotated by the fifth servomotor, which causes the roll 322 to rotate. The fourth guide roll 32 supports (nipples) the composite sheet AB and conveys it in the MD direction. The fifth servo motor is configured to rotate the roll 321 at a roll peripheral speed different from the roll peripheral speed of the third guide roll 31 .

In the contraction conveying mechanism 30 according to the present embodiment, the roll peripheral speed V4 of the fourth guide roll 32 on the downstream side is made slower than the roll peripheral speed V3 of the third guide roll 31 on the upstream side (V3>V4). By controlling the roll peripheral speed in this way, the transport speed of the composite sheet AB on the fourth guide roll 32 is made slower than that on the third guide roll 31 . Thereby, the composite sheet 12 can be shrunk between the third guide roll 31 and the fourth guide roll 32 . This contraction relaxes the stretched state of the stretchable sheet A1 when forming the composite sheet AB in a state in which tension is applied during transportation to a weakly stretched state. Therefore, the composite sheet AB is placed in a more stretched state than in its natural state in which no tension is applied. Due to this shrinkage, as illustrated in FIG. 2 , the sheet B is deformed so as to undulate in the MD direction along with the shrinkage of the stretchable sheet A, and folds W are formed. Along with this, the pitch width H between the plurality of seal points P is reduced in the MD direction and/or the CD direction compared to the composite sheet AB before shrinkage. The pitch width H is the distance between the seal points P in the MD and CD directions in a plan view of the composite sheet AB, and may be the distance between the outer sides of the seal points P or the distance between the inner sides of the seal points P. Alternatively, it may be the distance between the outer side and the inner side, or the distance between the point centroids of the seal points P. The interval between the points P in the MD direction is called a first pitch width H1, and the interval in the CD direction is called a second pitch width H2 (see FIG. 5).
Regarding the shrinkage of the composite sheet AB due to the control of the roll peripheral speed, the degree of shrinkage in the MD direction and the shrinkage in the CD direction is determined by the stretching direction of the tooth gap roll 13, that is, the extension of the teeth of the pair of rolls 131 and 132. It also depends on the direction. For example, if the teeth extend in the roll axis direction and the sheet A is stretched in the MD direction, the composite sheet AB shrinks more in the MD direction than in the CD direction. Further, when the teeth extend in the roll circumferential direction and the sheet A is stretched in the CD direction, the composite sheet AB shrinks more in the CD direction than in the MD direction.

The inspection device 40 has a control device 41 , a storage device 42 , an imaging device 43 , and a display device 44 , which are connected via a bus 45 as illustrated in FIG. 3 . The inspection device 40, each element (for example, the first to fifth servomotors) constituting the manufacturing device 100, and the illumination device 60 are connected so as to be able to communicate with each other. This connection may be wireless or wired, or may be via a network such as the Internet or a LAN (Local Area Network). The inspection device 40 is typically a personal computer, but is not limited to this, and may be an information processing device different from a personal computer, for example. Further, each of the control device 41, the storage device 42, the imaging device 43, and the display device 44 is typically configured integrally, but is not limited to this, and may be configured separately from each other.

The control device 41 is a device having a function of controlling each element constituting the manufacturing device 100 described above and a function of processing various data. The control device 41 includes, for example, a processor such as a CPU (Central Processing Unit). Note that the control device 41 may be configured with a single processor, or may be configured with a plurality of processors. Some or all of the functions of the control device 41 are realized by hardware such as a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array). may

The storage device 42 is a single memory or a plurality of memories that store the program PG executed by the control device 41 and the data used by the control device 41 (for example, the reference value B). The storage device 42 is composed of a commonly used recording medium such as a magnetic recording medium or a semiconductor recording medium. The reference value B stored in the storage device 42 is the value of the pitch width H between the seal points P in the MD and CD directions of the composite sheet AB shrunk to the target expansion/contraction ratio. Preferably, the reference value B has an upper limit and a lower limit. The expansion ratio is the ratio of the length in the MD and/or CD direction of the composite sheet AB after being shrunk to the length in the MD and/or CD direction of the composite sheet AB before being shrunk. The storage device 42 may be configured by a combination of multiple types of recording media. Also, the storage device 42 may be a portable storage medium or an external storage medium (for example, online storage) that can communicate with the control device 41 .

The imaging device 43 uses, for example, an imaging device such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device), and various members such as a lens for controlling the formation of an object image on the imaging device. , a device for capturing an image of the composite sheet AB (the surface of the sheet A) shrunk by the shrinkage conveying mechanism 30 and generating image data. The imaging device 43 is typically a device that captures still images, but is not limited to this, and may be a device that captures moving images, for example.

The display device 44 is a device that performs display under the control of the control device 41, and has a display section (not shown) and an input section (not shown). The display unit of the display device 41 is, for example, various display panels such as a liquid crystal display panel or an organic EL (electro-luminescence) display panel. The input unit of the display device 41 is, for example, various input means such as hardware buttons, a keyboard, a mouse, or a touch panel. The display unit of the display device 41 displays, for example, the peripheral speeds of the first guide roll 11 to the fourth guide roll 32 and the tooth groove roll 13, the conveying speeds of the sheet A, the stretchable sheet A1, the sheet B, and the composite sheet AB, and , sheet A, elastic sheet A1, sheet B and tension applied to composite sheet AB are displayed. Data relating to each of these parameters is displayed on the display section, and the data is input to the input section by the user and transmitted to the control device 41 .

In the inspection apparatus 40 according to the present embodiment, the control device 41 reads the program PG from the storage device 42 and executes it, so that the control device 41 controls the image data acquisition unit 411, the pitch measurement unit 412, the contraction state determination unit 413, It functions as an image processing unit 414 , a contraction control unit 415 , a seal point measurement unit 416 and a roll state determination unit 417 .

The image data acquisition unit 411 acquires image data generated by imaging the composite sheet AB shrunk by the shrinkage conveying mechanism 30 with the imaging device 43 . The pitch measurement unit 412 measures the pitch width H between the seal points P formed on the composite sheet AB by the seal mechanism 20 based on the image data.

The contraction state determination unit 413 determines the contraction state of the composite sheet AB from the pitch width H measured by the pitch measurement unit 412 . The image processing unit 414 performs predetermined image processing on the image data acquired by the image data acquiring unit 411 from the imaging device 43 . The shrinkage control unit 415 controls the expansion/contraction ratio of the composite sheet AB based on the determination result of the shrinkage state determination unit 413 . The seal point measurement unit 416 measures the number and area of the seal points P on the composite sheet AB based on the image data acquired by the imaging device 43 . The roll state determination unit 417 determines the state of the pattern roll 21 forming the points P on the composite sheet AB based on the measurement result of the point measurement unit 416 .
In the present embodiment, the functions of the control device 41 (image data acquisition unit 411, pitch measurement unit 412, contraction state determination unit 413, image processing unit 414, contraction control unit) are performed by a plurality of devices configured separately from each other. 415, seal point measurement unit 416, and roll state determination unit 417) may be realized, and part or all of the functions of the control device 41 may be realized by a dedicated device.

The lighting device 60 is a light that is provided downstream of the shrinkage conveying mechanism 30 in the MD direction and that illuminates the back surface of the sheet B. As shown in FIG. Lighting/lighting out of the illumination device 60 is controlled by the control device 41 . Although the light source of the illumination device 60 is not particularly limited, for example, an LED (Light Emitting Diode) light source is adopted. In this case, the type of the LED light source is not particularly limited, and for example, a bullet type, FLUX type, surface mount type (SMD), COB (Chip On Board) type, or the like is adopted. The color of the light source is also not particularly limited, and is appropriately determined according to the specifications and application of the manufacturing apparatus 100. For example, it may be white, yellow, green, blue, red, or orange, preferably blue. .

Next, a method for manufacturing a composite sheet using the aforementioned manufacturing apparatus 100 will be described as a preferred embodiment of the method for manufacturing a composite sheet according to the present invention.

As illustrated in FIG. 4, the manufacturing method of the composite sheet of the present embodiment includes a stretching step (step St1), a sealing step (step St2), a contraction conveying step (step St3), and an image data acquisition step ( It has a step St4), a pitch measurement step (step St5), a contraction state determination step (step St6), and a contraction control step (step St8). These steps will be described below with reference to FIGS. 1, 3 and 4 as appropriate.

[Step St1: Stretching step]
The first guide roll 11 unwinds the sheet A containing the stretchable material from the original fabric roll R1 and continuously supplies it toward the tooth groove roll 13 in the MD direction. A continuously supplied sheet A is stretched by a tooth gap roll 13 and pulled out from the tooth gap roll by a second guide roll 12 .
In this series of processing steps, the conveying speed and/or By controlling the tension, the sheet A (and the elastic sheet A1 after stretching the sheet A) is given a stretching force in the conveying direction. Specifically, by controlling the roll peripheral speed V2 of the second guide roll 12 to be faster than the roll peripheral speed V1 of the first guide roll 11 (V2>V1), the sheet A and the stretchable sheet A1 is extended in the conveying direction.
The stretching of the sheet A in the stretched state is performed by meshing the tooth spaces of the pair of rolls 131 and 132 of the tooth space roll 13 . Stretchable sheet A1 is formed by this stretching. More specifically, the teeth T1 and T2 arranged on the respective peripheral surfaces of the rolls 131 and 132 are meshed with each other so as to enter grooves on the peripheral surfaces of the rolls facing each other, and the meshed rolls 131 are rotated. The sheet A between the tooth T1 and the tooth T1 of the roll 132 is partially stretched. As a result, the stretchable sheet 12 in which the stretchability of the stretchable material contained in the sheet A is exhibited more strongly is formed. Processing using such a tooth groove roll 13 is, for example, the method described in paragraphs [0012] to [0040] of JP-A-2007-177384, and the method described in paragraphs [0055] to [0085] of JP-A-2008-179128. method.

[Step St2: Sealing process]
Next, the sealing mechanism 20 unwinds the sheet B from the raw fabric roll R2. At the same time, the stretchable sheet A1 stretched in the previous step St1 is transported in the MD direction in a stretched state, and the stretchable sheet A1 and the sheet B are overlapped and point-sealed. For example, as illustrated in FIG. 2, a plurality of seal points P are intermittently formed in the MD and CD directions. As a result, a composite sheet AB is formed in which the elastic sheet A1 and the sheet B are joined (point-sealed) via a plurality of seal points P. As shown in FIG. The number of sheets B may be one, or two or more. In this sealing step, the elastic sheet A1 preferably maintains the stretched state in the stretching step.
Further, in the [sealing step], the point sealing is preferably welded by ultrasonic waves.

[Step St3: Contraction Conveying Step]
Next, the contraction conveying mechanism 30 conveys the composite sheet AB formed in the previous step St2 in an elongated state in the MD direction while contracting the composite sheet AB to the target expansion/contraction ratio. This shrinkage is the MD and/or CD shrinkage of composite sheet AB. The contraction is performed by controlling the roll peripheral velocity by the control device 41 such that "the roll peripheral velocity V3 of the third guide roll 31>the roll peripheral velocity V4 of the fourth guide roll 32". As a result, the composite sheet AB, which has been stretched by the tension that accompanies transportation, is shrunk to the target stretch ratio (target stretch ratio), and is brought into a slightly stretched state.
Due to this shrinkage, the stretchable sheet A1 shrinks and folds W are formed in the sheet B as illustrated in FIG. For example, it can be a composite sheet AB having fine folds such as micropleats. This shrinkage also reduces the pitch width H between the seal points P in the MD and/or CD directions from the state during the sealing process.

As described above, the expansion ratio is the ratio of the length in the MD direction and/or the CD direction of the composite sheet AB after being shrunk to the length in the MD direction and/or the CD direction of the composite sheet AB before being shrunk. percentage. "Before being shrunk" refers to the point at which point seals are formed in the sealing process. "After being shrunk" refers to the point of time immediately after the shrunk and conveying process.
While the composite sheet AB is continuously conveyed, the length before being shrunk and the length after being shrunk are measured by the pitch width H (H1, H2) (see FIG. 5).
Then, in the contraction conveying process, in order to shrink the composite sheet AB so as to achieve the target expansion/contraction ratio, the theoretical roll peripheral speed V3 and the roll peripheral speed V4 that achieve the target expansion/contraction ratio are calculated, and the calculated values are controlled in advance. set to the device. By controlling the roll peripheral velocity V3 and the roll peripheral velocity V4 according to the setting, the target expansion/contraction ratio is achieved.

Composite sheet AB that is shrunk and conveyed in the [shrinking and conveying step] is in a more stretched state than the natural state as a product, but is shrunk to the target stretch ratio and the stretched state is weakened. As a result, it is possible to reduce processing defects and the like in subsequent processing steps for the composite sheet AB caused by being in the stretched state. For example, when carrying out the process of conveying the composite sheet AB after shrinkage and bonding it to another sheet, since the bonding is performed in a state close to the product state, twisting of the bonded portion due to the shrinkage of the composite sheet AB can be reduced. , can be manufactured with good product function and appearance. In particular, when forming joints that intersect the extending direction of the folds W, twisting due to shrinkage is likely to occur, so the effect of reducing twisting and improving the appearance is high. However, conventionally, in the conveyed composite sheet AB, the actual expansion/contraction ratio may fluctuate due to the characteristics of the sheet material and other factors, resulting in deviation from the target expansion/contraction ratio. In contrast, in the present embodiment, the presence or absence of the divergence is measured and inspected in the following steps, and control is performed to optimize the expansion/contraction magnification. In subsequent steps, the pitch width H is measured, and it is possible to determine whether or not there is a deviation between the target expansion/contraction ratio and the actual expansion/contraction ratio, and the degree of the difference.

[Step St4: Image data acquisition step]
Subsequently, the imaging device 43 images the surface of the sheet A of the composite sheet AB shrunk in the previous step St3 at predetermined time intervals to acquire image data. The acquired image data is transmitted to the image data acquisition unit 411 . At this time, it is preferable that the edge E of the composite sheet AB in the CD direction falls within the angle of view of the imaging device 43 . The image data acquisition unit 411 transmits image data acquired from the imaging device 43 to the image processing unit 414 .

It is preferable that the image data acquired in the [image data acquisition step] undergo an image processing step in which the image processing unit 414 performs binarization processing based on a predetermined threshold to generate binarized image data. In the binarization process, pixels whose luminance is equal to or higher than the threshold value of the captured image are binarized as white, and pixels whose luminance is equal to or lower than the threshold value are binarized as black. Thereby, the distinguishability of the seal point P of the composite sheet AB can be improved.

[Step St5: Pitch measurement process]
Next, the pitch measurement unit 412 measures the pitch width H (see FIG. 5) between the seal points P formed on the composite sheet AB in the sealing process based on the image data. The pitch measurement unit 412 outputs data regarding this pitch width H to the contraction state determination unit 413 . In the example shown in FIG. 6, the pitch width H is the distance between the outer sides of the seal points P. In the example shown in FIG. However, the pitch width H may be the distance between the insides of the seal points P.
The pitch width H is preferably the average value of the pitch widths H in the image data. That is, the average value of the pitch width H is calculated for each image data, and a time-series group of the average values of the pitch width H corresponding to the image data acquired in time series is obtained.
In the pitch measurement step, it is preferable to measure at least one of the first pitch width H1 in the MD direction between each point P and the second pitch width H2 in the CD direction, and both may be measured. More preferred (see FIG. 5).

In the pitch measurement step, by measuring the pitch width H between the seal points P, the expansion/contraction ratio can be measured. In addition, since the pitch measurement process is based on the image data of the composite sheet AB that has been shrunk through the shrinkage conveying process, the pitch width H changes due to the shrinkage, and the above measurement can be performed in a state closer to the product state. can be done.

[Step St6: contraction state determination step]
Next, the contracted state determination unit 413 determines the contracted state of the composite sheet AB based on the data regarding the pitch width H obtained from the pitch measurement unit 412 . The contraction state determination section 413 outputs this determination result to the contraction control section 415 . If the pitch width H is within the predetermined range (YES in step St7), the composite sheet AB is conveyed while maintaining its shrunk state, and is moved to the next step. On the other hand, if the pitch width H is not within the predetermined range (NO in step St7), the controller 41 executes step St8.

In determining the contracted state of the composite sheet AB, it is preferable to determine whether or not the pitch width H is within a predetermined range (the allowable range and the value set as the reference value B described above). By comparing the pitch width H with a predetermined range to determine the quality of the contracted state, it is possible to determine whether the composite sheet AB is not only insufficiently contracted but also excessively contracted. The pitch width H in this case may be the pitch width H of each seal point P, or may be the average value of the pitch width H of the seal points P for each image data.

In the [shrinkage state determination step], it is preferable to determine the shrinkage state of the composite sheet AB based on both the first pitch width H1 in the MD direction and the second pitch width H2 in the CD direction. As a result, it is possible to improve the measurement accuracy of the expansion/contraction ratio of the composite sheet AB that has undergone the shrinking process.

[Step St8: Contraction control step]
Subsequently, the shrinkage control unit 415 controls the expansion/contraction ratio of the composite sheet AB based on the determination result of the shrinkage state determination step.
As for this control, it is preferable to perform control so as to reduce the difference between the pitch width H and the reference value B when the pitch width H is not within a predetermined range. In this case, the pitch width H is preferably an average value for each image data. For example, the difference between the average value of the measured pitch width H (actual value) and the pitch width H (reference value, ideal value) of the target expansion/contraction ratio is calculated, and fed back to the conveying system (servo motor) to reduce the difference. make it
Reduction of the above difference can be performed by controlling the drive source (fourth servomotor, fifth servomotor) that drives the mechanism for shrinking the composite sheet AB in the shrinkage conveying process. Specifically, when it is determined that the pitch width H exceeds the upper limit of the predetermined range, that is, the composite sheet AB is insufficiently shrunk, the difference between the pitch width H and the reference value B is reduced as much as possible. (for example, so that the average value is within ±10% of the upper limit of the reference value B), the roll peripheral speed of the fifth servo motor that drives the roll 321 is reduced, or the roll 311 is The roll peripheral speed of the fourth servomotor to be driven is increased. As a result, the stretched state of the composite sheet AB is further weakened to lower the stretch ratio and narrow the pitch width so that it falls within the reference value B. On the other hand, when the average value of the pitch width H is below the lower limit value of the predetermined range, that is, when it is determined that the composite sheet AB is excessively shrunk, the difference between the average value and the reference value B is reduced as much as possible. (For example, so that the average value is within the range of ±10% of the lower limit of the reference value B), increase the roll peripheral speed of the fifth servo motor that drives the roll 321, or increase the roll peripheral speed of the roll 311 4 Decrease the roll peripheral speed of the servo motor. As a result, the stretched state of the composite sheet AB is increased to increase the expansion/contraction ratio, widen the pitch width, and set the pitch width within the reference value B.
As a result, even if there are factors that change the expansion/contraction ratio of the composite sheet AB, such as variations in the properties of the raw material, the expansion/contraction ratio of the composite sheet AB in the shrinking step can be maintained well and conveyed to the subsequent processing step. can.

According to the method for manufacturing a composite sheet of the present embodiment, it is possible to convey the composite sheet AB at a desired expansion/contraction ratio, and in the subsequent processing steps, it is possible to satisfactorily manufacture a product using the composite sheet. quality can be enhanced and stabilized.

In the method of manufacturing the composite sheet of the present embodiment, in parallel with the shrinkage conveying step (step St3) to the shrinkage control step (step St8), the seal point measurement step (step St9) and the roll state determination step ( It is preferable to perform step St10).
These steps St9 and St10 will be described.

[St9: Seal point measurement step]
The point measurement unit 416 measures the number and area of the seal points P in the captured image in the image data acquired in the image data acquisition step (step St4). The point measurement section 416 outputs the measurement result to the roll state determination section 417 .
In the above measurement, the image processing unit 414 preferably provides an inspection window M for the image data and determines the number and area of the seal points P per unit area (see FIG. 7). Said area is preferably the sum of the areas of each seal point P within the inspection window M. Moreover, it is preferable to measure the number and area of the seal points P based on the binarized image data.
In this process, not only the pitch width H between the seal points P but also the state of the seal points P are measured. As a result, it is possible to obtain data for determining whether the seal points P themselves are properly formed, that is, whether the surface condition of the pattern roll 21 of the sealing mechanism 20 is appropriate.

[St10: Roll state determination step]
The roll state determination unit 417 determines the state of the pattern roll 21 forming the seal points P on the composite sheet AB based on the measurement result obtained by the point measurement unit 416 in the seal point measurement process.
By this determination, the surface condition of the pattern roll 21 (chipping or reduction of projections) can be known in-line and timely from the surface condition of the composite sheet. The surface condition of the pattern roll 21 affects the sealing failure of the product, and can contribute to the quality improvement and quality stabilization of the composite sheet AB in combination with the measurement and determination of the pitch width H described above.

The roll state determination unit 417 outputs the roll state determination result to the display device 41 . The display device 41 displays the state of the pattern roll 21 determined by the roll state determination unit 417 and notifies the user of it. Based on the notification, the roll is repaired or replaced, and production of composite sheet AB is resumed.
In the manufacturing method of the composite sheet AB of the present embodiment, the expansion/contraction ratio is controlled based on the pitch width H described above, and the surface condition of the pattern roll 21 for point sealing is inspected. , the quality of the product containing the composite sheet AB can be further improved and the quality can be more stabilized.

In the method for manufacturing the composite sheet AB of the present embodiment, the materials of the sheet A and the sheet B as raw material sheets are not particularly limited, and various materials that can impart stretchability to the composite sheet AB can be employed.
For example, the sheet A contains a stretchable material as described above, and may consist of only a stretchable material, or may contain a stretchable material and a non-stretchable material. In particular, when the sheet A contains a stretchable material and a non-stretchable material, the non-stretchable material is stretched by the stretching process described above to reduce the stretch resistance of the stretchable material, resulting in a high-strength, high-stretch composite sheet AB. can be preferably formed.
The "elasticity" of the stretchable material referred to here means that a material with a length of 100 is stretched to a length of 150 by applying a force in one direction, and then by dividing the force, it can be stretched to a length of 100 or more and 110 or less. It refers to the property of shrinking. The "non-stretchability" of a non-stretchable material refers to the property that it cannot be stretched to a length of 150 or that it does not shrink to a length of 100 or more and 110 or less when the force is removed even if it can be stretched.

The sheet A may be a single-layer sheet or a multi-layer laminated sheet.
Single-layer sheets include, for example, sheets obtained by blending elastic fibers and non-elastic fibers. Examples of laminated sheets include those obtained by laminating and bonding a non-elastic layer containing non-elastic fibers on one or both sides of an elastic layer containing elastic fibers. The elastic layer and the non-elastic layer are preferably fiber layers such as non-woven fabric. Also, the elastic layer may be an elastic film-like layer or a net-like layer instead of the fiber layer. Another example of the laminated sheet includes a sheet in which a plurality of elastic filaments are arranged between a pair of inelastic layers so as to extend in the longitudinal direction (conveyance direction) Y of the sheet without intersecting each other. The terms "elasticity" and "non-elasticity" used herein are synonymous with the definitions of "elasticity" and "non-elasticity" described above. The stretchable material contained in the raw material sheet 11 may be such elastic fibers, elastic layers and elastic filaments.

The elastic fibers are preferably made of an elastic material. Examples of the elastic material include thermoplastic elastomers, rubbers, ethylene-propylene copolymers, and the like. Among these, thermoplastic elastomers are preferred because fibrous elastic bodies can be molded relatively easily. Examples of thermoplastic elastomers include polyurethane, styrene (SBS, SIS, SEBS, SEPS, etc.), olefin (copolymers of ethylene, propylene, butene, etc.), vinyl chloride, polyester, and the like. These can be used individually by 1 type or in combination of 2 or more types.

In the elastic layer containing the elastic fibers, the content of the elastic fibers in the elastic layer is preferably 50% by mass or more and 100% by mass or less, more preferably 75% by mass or more and 100% by mass or less. Inelastic resins such as polyethylene, polypropylene, polyester (polyethylene terephthalate and polybutylene terephthalate), nylon, etc., organic or inorganic pigments, various additives (antioxidants, plasticizers, etc.) can also include Inelastic fibers, organic or inorganic pigments can also be included in the first fibrous layer. When the elastic layer is in the form of a film or a net, the various elastic resins described above can be used as the material for forming the film or the net.

Examples of the inelastic fibers include fibers made of biodegradable resins such as polyethylene, polypropylene, polyester (polyethylene terephthalate and polybutylene terephthalate), nylon and polylactic acid.
In the inelastic layer containing the inelastic fibers, the constituent fibers may be short fibers or long fibers, and may be hydrophilic or water-repellent. In addition, core-sheath type conjugate fibers, split fibers, modified cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more.

Preferably, the inelastic layer containing the inelastic fibers is extensible. Here, "stretchable" means (a) the case where the constituent fibers themselves are stretched, and (b) even if the constituent fibers themselves are not stretched, the fibers bonded at the intersection point are separated or the fibers are separated. It includes the case where the three-dimensional structure formed by a plurality of fibers is structurally changed due to bonding or the like, the constituent fibers are torn, or the slack of the fibers is stretched, so that the inelastic layer as a whole is stretched.
The inelastic layer may already be extensible in a state prior to the stretching process described above. Alternatively, it may be one that is not stretchable in a state before stretching, but becomes stretchable after being stretched. From the viewpoint of improving the transportability of the raw material sheet containing the inelastic layer, it is preferable that the inelastic layer is not stretchable before stretching.

The elastic filaments may be thread-like synthetic rubber or natural rubber. Alternatively, it may be obtained by dry spinning (melt spinning) or wet spinning. The elastic filaments are preferably obtained by direct melt spinning without being wound once.
The elastic filament is preferably obtained by drawing an undrawn yarn.
The elastic filament is preferably formed by drawing an elastic resin in a melted or softened state. As a result, the elastic filaments can be properly bonded to the inelastic layer in a non-stretched state. The drawing process when using such elastic filaments can be performed by the method described in paragraphs [0055] to [0085] of JP-A-2008-179128.

On the other hand, as the sheet B, various materials that can be sealed against the elastic sheet A1 can be used without particular limitation. Among these, it is preferable that the stretchability is lower than that of the sheet A.

Although the embodiments of the method for manufacturing a composite sheet of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be modified in various ways.

10 stretching mechanism 11 first guide roll 12 second guide roll 13 tooth gap roll 20 sealing mechanism 21 roll 22 seal point forming device 30 shrinking mechanism 31 third guide roll 32 fourth guide roll 40 inspection device 60 illumination device A sheet A1 expansion and contraction Sex sheet B Other sheets

Claims (9)

A step of stretching a sheet containing an elastic material;
A sealing step of overlapping the elastic sheet obtained by the stretching step of the sheet and another sheet and performing point sealing to form a composite sheet;
A contraction conveying step of conveying the composite sheet in a stretched state and shrinking the composite sheet to a target expansion/contraction ratio;
an image data acquisition step of acquiring image data by imaging the surface of the composite sheet shrunk in the shrinkage conveying step;
a pitch measuring step of measuring the pitch width of the seal points formed on the composite sheet in the sealing step based on the image data;
a contraction state determination step of determining a contraction state of the composite sheet based on the pitch width;
a shrinkage control step of controlling the expansion/contraction ratio of the composite sheet based on the determination result of the shrinkage state determination step;
A method of manufacturing a composite sheet comprising The method of manufacturing a composite sheet according to claim 1, wherein in the shrinkage control step, a difference between the pitch width measured in the pitch measurement step and a reference value is reduced. 3. The method of manufacturing a composite sheet according to claim 2, wherein in the shrinkage control step, a drive source for driving a mechanism for shrinking the composite sheet in the shrinkage conveying step is controlled based on the difference. In the pitch measurement step, both a first pitch width of the seal points in the conveying direction of the composite sheet and a second pitch width of the seal points in a width direction orthogonal to the conveying direction are measured,
The method for manufacturing a composite sheet according to any one of claims 1 to 3, wherein in the shrinkage state determination step, the shrinkage state of the composite sheet is determined based on both the first pitch width and the second pitch width. . In the shrinkage state determination step,
determining whether the pitch width of the seal points is within a predetermined range;
The method for manufacturing a composite sheet according to any one of claims 1 to 4, wherein the shrinkage state of the composite sheet is determined based on the determination result. 6. The method according to any one of claims 1 to 5, further comprising an image processing step of binarizing the image data obtained by the image data obtaining step based on a predetermined threshold to generate binarized image data. A method of manufacturing a composite sheet. In the stretching step,
In the sheet conveying direction, the conveying speed and/or the tension are controlled by the first guide roll on the upstream side and the second guide roll on the downstream side with respect to the sheet, and the elongation force in the conveying direction is applied to the sheet. ,
The first guide roll supplies the sheet to a tooth gap roll provided between the first guide roll and the second guide roll,
The method for producing a composite sheet according to any one of claims 1 to 6, wherein the supplied sheet is stretched by the tooth space roll and pulled out from the tooth space roll by the second guide roll. a seal point measuring step of measuring the number and area of seal points of the composite sheet based on the image data;
The composite sheet according to any one of claims 1 to 7, further comprising a roll state determination step of determining the state of the pattern roll forming the seal points on the composite sheet based on the measurement result of the seal point measurement step. manufacturing method. The method for producing a composite sheet according to any one of claims 1 to 8, wherein in the sealing step, the point sealing is welding by ultrasonic waves.

Images