JP2011125638A - Method of manufacturing stretch sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a stretch sheet keeping a required width after elongation process while the stretch property of the sheet is held constant. <P>SOLUTION: A method of manufacturing a stretch sheet of this invention by drawing a complex sheet includes a drawing process in which the complex sheet 10 is continuously supplied to the engaged part in the carrying direction (Y direction), where a pair of tooth groove rolls 2, 3 are mutually engaged, and the stretch property is added to the complex sheet 10 between the tooth groove rolls 2, 3. The method of manufacturing the stretch sheet has a width detection process for detecting the width W of the stretch sheet 10' obtained after the drawing process. The method of manufacturing the stretch sheet also has a control process for controlling the depth of the engagement of the engaged part and/or the rotation speed of the tooth groove rolls 2, 3 based on the difference of width W of the detected stretch sheet 10' and the setting width Wa of the stretch sheet 10'. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing an elastic sheet, a method for producing a pants-type wearing article, and a method for processing a sheet.

  A technique of using a stretching apparatus having a pair of rolls having tooth grooves engaged with each other on the peripheral surface portion, rotating the rolls to supply a sheet of nonwoven fabric or the like to the meshed portions, and stretching the sheet Has been proposed (see Patent Document 1 below).

  By the way, when a sheet is processed between a pair of rolls having a tooth gap as in the technique described in Patent Document 1, a sheet stretched at a high stretch ratio is softened and stretched because of its elasticity. Cheap. For this reason, due to fluctuations in conveyance tension caused by the winding tension of the original sheet before stretching, fluctuations in basis weight of the original sheet before stretching, fluctuations in basis weight due to lot differences in the original sheet before stretching, etc. In some cases, the sheet width after the stretching process fluctuates, and an article having a required degree of completeness cannot be manufactured.

  As a method of supplying a stretched sheet with stretchability to a manufacturing apparatus with a constant width, the side edge of the sheet is shifted when the side edge of the sheet deviates from a required position as in Patent Document 2 below. There are some which make the sheet width constant by changing the direction of the guide roll in contact with the vicinity and correcting the side edge position of the sheet. However, in this method, since the stretched sheet is soft and easily stretched, a difference occurs between the stretchability near the sheet side edge that is in contact with the guide roll and the stretchability near the center of the sheet that is not in contact.

  Further, since the control of the guide roll is performed independently for each side edge of the sheet, there is a problem that a difference in elasticity between one side edge of the sheet and the elasticity near the other side edge of the sheet occurs. . Further, as described above, since a sheet processed at a high draw ratio is soft and easily stretched, if the side edge position of the sheet is controlled by bringing the guide roll into contact with the sheet, it may not be stable. In addition, when manufacturing pants-type wearing articles using elastic sheets, when changing the draw ratio by changing the size, product specifications, etc., the control of the guide roll will be optimal each time the draw ratio is changed. It is necessary to adjust to this, and it cannot be easily handled. In addition, when the sheet width is greatly changed by changing the size of the pants-type wearing article, it is necessary to change the position of the guide roll, and the convenience may be impaired.

JP2007-177384A JP 2004-262556 A

  Therefore, the present invention has been made in view of the above problems, and manufactures an elastic sheet in which the width of the sheet after the stretching process maintains the required width and the stretchability of the sheet after the stretching process is kept constant. An object of the present invention is to provide a method for producing a stretchable sheet.

  The present invention relates to a method for producing an elastic sheet, in which a composite sheet is stretched to obtain an elastic sheet, wherein the composite sheet is continuously supplied in the conveying direction to meshing portions of a pair of tooth gap rolls that mesh with each other, A stretching step for imparting stretchability to the composite sheet between the tooth space rolls, a width detection step for detecting the width of the stretchable sheet obtained through the stretching step, and the detected width of the stretchable sheet. And a control step of controlling the engagement depth of the meshing portion and / or the rotational speed of the pair of tooth gap rolls based on a difference from a preset set width of the elastic sheet. The manufacturing method of this is provided.

  According to the method for producing a stretchable sheet of the present invention, it is possible to produce a sheet in which the stretched sheet has a required width and the stretchability of the stretched sheet is kept constant.

FIG. 1 is a perspective view schematically showing a sheet processing apparatus used in the elastic sheet manufacturing method of the first embodiment of the present invention and a manufacturing process of the elastic sheet using the same. 2A and 2B are schematic diagrams for explaining a sheet width detection method by the detection unit, in which FIG. 2A is a plan view of an imaging portion of the sheet, and FIG. 2B is an example of pixel data of the imaging portion. It is. 3A and 3B are schematic diagrams for explaining a sheet width detection method by the detection unit. FIGS. 3A and 3B are diagrams illustrating an example of pixel data in the inspection region, and FIG. ) And FIG. 3D are diagrams showing the results obtained by differentiating the pixel data in the inspection region. FIG. 4 is a perspective view schematically showing a sheet processing apparatus used in the elastic sheet manufacturing method of the second embodiment of the present invention and a manufacturing process of the elastic sheet using the same. FIG. 5: is a perspective view which shows typically the one embodiment applied to the manufacturing method of a disposable diaper using the processing method of the underpants type wearing article of this invention.

  Hereinafter, the manufacturing method of the elastic sheet of this invention is demonstrated, referring drawings based on the preferable 1st embodiment. FIG. 1 schematically shows a processing apparatus (hereinafter also simply referred to as a processing apparatus) used in the method for producing a stretchable sheet according to the first embodiment.

  As shown in FIG. 1, the processing apparatus 1 of the first embodiment includes a pair of tooth groove rolls 2 and 3 having tooth grooves meshing with each other on the peripheral surface portion, and these tooth groove rolls 2 and 3 are rotated. In some cases, the composite sheet 10 supplied to the meshing portions is stretched to give stretchability. Note that the Y direction in the figure is a direction in which the composite sheet 10 fed from a raw fabric (not shown) is conveyed, and the X direction in the figure is the width direction of the composite sheet 10.

  As shown in FIG. 1, the processing device 1 of the first embodiment includes a tooth groove processing means 7 that imparts stretchability to the sheet base material 10 by the tooth engagement depth and rotation speed of the tooth groove rolls 2 and 3, and Width detecting means 4 for detecting the width W of the stretchable sheet 10 ′ obtained by stretching the composite sheet 10 on the downstream side of the conveying direction (Y direction) with respect to the tooth groove processing means 7, and the tooth groove Tension applying means 5 and 6 for applying tension to the composite sheet 10 before processing by the rolls 2 and 3 and the stretchable sheet 10 ′ after processing, and the width W of the stretchable sheet 10 ′ detected by the width detecting means 4 in advance. Control means 8 for controlling the stretchable sheet 10 ′ to have the set width Wa by changing the meshing depth and the rotational speed of the tooth gap machining means 7 based on the difference from the set width Wa, and And setting means 9.

  The tooth gap processing means 7 includes a pair of tooth groove rolls 2 and 3 meshing with each other, and the tooth groove rolls 2 and 3 are constituted by rolls of the same form, and as shown in FIG. A plurality of 31 are provided along the axis of each roll. Specifically, as shown in FIG. 1, the teeth 21 and 31 of each roll have a direction in which the teeth 21 and 31 extend on the tooth gap rolls 2 and 3 and a rotation axis of the tooth gap rolls 2 and 3. It is provided in the peripheral surface part of the tooth gap rolls 2 and 3 so as to be parallel to each other, and a groove is formed between the teeth 21 and 21 or between the teeth 31 and 31. The tooth gap rolls 2 and 3 are provided at the meshing portions so that the teeth 21 and the teeth 31 mesh with each other.

  The pitch between adjacent teeth 21 and 21 in the tooth gap roll 2 is preferably 1.5 to 3.5 mm, and more preferably 2.0 to 3.0 mm. The width at the base of each tooth 21 is preferably 0.25 times to less than 0.5 times the pitch, and more preferably 0.3 times to 0.4 times. The height of each tooth 21 is preferably 1.0 to 2.0 times the tooth pitch P, and more preferably 1.25 to 1.75 times. Here, the pitch between adjacent teeth in the tooth gap roll refers to the distance between the center line of one tooth and the center line of an adjacent tooth. In addition, the width | variety of a tooth | gear is not uniform, The trapezoid type tooth | gear which narrows toward the front-end | tip of a tooth | gear from a tooth | gear base may be sufficient. The height of the tooth refers to the length from the root to the tip of the tooth. The corners of the tips of the teeth 21 are preferably chamfered. Further, the tooth 31 in the tooth gap roll 3 is the same as the tooth 21 in the tooth gap roll 2.

  In consideration of imparting excellent stretchability to the material, the meshing depth of the teeth 21 and 31 of the tooth gap rolls 2 and 3 is preferably equal to or greater than the pitch when the pitch is in the above range. Is preferably 1.0 mm or more, and more preferably 2.0 mm or more. Here, the meshing depth of teeth refers to a length in which adjacent teeth 21 and 31 overlap when the tooth gap rolls 2 and 3 are meshed and rotated.

  In the processing apparatus 1 of the first embodiment, the tooth gap rolls 2 and 3 mesh with the teeth 21 and 31 when the driving force from the servo motor 71 that drives the roll 2 is transmitted as shown in FIG. Rotate. In addition to the teeth 21 and 31, a general gear defined in JIS B1701 may be attached to each shaft of the tooth gap rolls 2 and 3 as a drive transmission gear. As a result, the teeth 21 and 31 of the tooth gap rolls 2 and 3 are not engaged with each other, but the drive transmission gears are engaged with each other, so that the drive is transmitted to the tooth groove rolls 2 and 3. Can be rotated. In this case, the teeth 21 and 31 of the tooth gap rolls 2 and 3 do not contact each other.

  As shown in FIG. 1, the tooth gap processing means 7 includes a servo motor 71 that drives the above-described tooth gap roll 2, servo motors 74 and 75, and a servo motor for adjusting the engagement depth of the teeth 21 and 31. And meshing depth adjusting sections 72 and 73 which are adjusted by motors 74 and 75. In the processing apparatus 1 of the first embodiment, the meshing depth adjusting portions 72 and 73 are attached to the shafts at both ends in the X direction of the tooth gap roll 3 as shown in FIG. When the servo motors 74 and 75 are rotated, the tooth gap roll 3 is raised or lowered by the meshing depth adjusting units 72 and 73 based on the rotation direction of the servo motors 74 and 75. When the tooth gap roll 3 rises to the tooth gap roll 2 side, the engagement between the teeth 21 of the tooth gap roll 2 and the teeth 31 of the tooth gap roll 3 becomes deeper. Conversely, when the tooth gap roll 3 descends, the tooth gap roll 3 The meshing between the second tooth 21 and the tooth 31 of the tooth gap roll 3 becomes shallow.

  As shown in FIG. 1, the width detection unit 4 includes a CCD (charge coupled device) camera (imaging device) 41 that images the stretchable sheet 10 ′ conveyed in the conveyance direction (Y direction) at a predetermined angle of view. An illuminator 42 that illuminates the imaging portion from the back side, and an image processing device 43 that receives image data captured by the CCD camera 41 and performs image processing to detect the positions of the end portions 101 and 102 of the stretchable sheet 10 ′. I have. The image processing apparatus 43 can detect the width W of the stretchable sheet 10 ′ obtained through the stretching process from the position data of the end portions 101 and 102 of the stretchable sheet 10 ′.

  As shown in FIG. 1, the tension applying means 5 includes a pair of feed rolls 51, 52 arranged on the upstream side of the tooth gap rolls 2, 3, and a servo motor 53 that drives the feed rolls 51, 52. ing. The tension applying means 6 includes a pair of feed rolls 61 and 62 disposed on the downstream side of the tooth gap rolls 2 and 3 and a servo motor 63 that drives the feed rolls 61 and 62. Since the rotation speed of the feed rolls 61 and 62 is higher than the rotation speed of the feed rolls 51 and 52, tension is applied to the conveyed sheet between the hood rolls 51 and 52 and the feed rolls 61 and 62.

  As shown in FIG. 1, the control means 8 includes a servo amplifier 83 that controls a servo motor 71 that drives the tooth gap roll 2, and a servo that controls servo motors 74 and 75 that adjust the meshing depth of the teeth 21 and 31. Based on the difference between the amplifiers 85 and 86 and the sheet width W detected by the image processing apparatus 43 and the preset width Wa of the stretchable sheet 10 ′, an operation control command corresponding to the servo amplifiers 83, 85 and 86 is issued. And an arithmetic processing unit 81 for outputting. The arithmetic processing unit 81 outputs an operation control command corresponding to the servo amplifiers 84 and 82 that control the servo motor 53 of the tension applying unit 5 and the servo motor 63 of the tension applying unit 6.

  The display / setting unit 9 includes a screen for displaying an image processed by the image processing device 43 and a setting device for setting the arithmetic processing unit 81. The preset width of the stretchable sheet 10 ′ required for control, the reference speed of the tooth groove rolls 2 and 3, the reference meshing depth of the tooth groove rolls 2 and 3, the set tension of the elastic sheet 10 ′, Data such as a correction coefficient is input from the display / setting unit 9, and these data are transmitted from the display / setting unit 9 to the arithmetic processing unit 81.

  In the processing apparatus 1 of the first embodiment, a free roll 15 is disposed between the tooth gap processing means 7 and the width detection means 4. Since the free roll 15 can moderately hold the stretchable sheet 10 ′ and prevent the stretchable sheet 10 ′ from being turned or wrinkled, the width detecting means 4 stably detects the width of the stretchable sheet 10 ′. be able to.

  Below, the composite sheet 10 used by this invention is demonstrated. The case where the composite sheet 10 becomes a stretchable sheet 10 ′ that exhibits stretchability by being stretched is referred to herein as a latent stretchable sheet. The latent elastic sheet does not substantially stretch in a predetermined direction before being subjected to the stretching process, but after the stretching process is performed, a portion of the sheet subjected to the stretching process is in the predetermined direction. It becomes a stretchable sheet after being stretched. Regarding the latent stretchable sheet, when referring to a state in which stretchability is exhibited after being stretched, it is referred to as a stretchable sheet 10 ′.

  When the composite sheet 10 is a latent elastic sheet, the sheet does not substantially extend in a predetermined direction before being stretched. Specifically, it is preferable that the latent elastic sheet has a maximum elongation in the Y direction of 10% or less (the length only extends up to 1.1 times) before being stretched. More preferably, the maximum elongation in the direction is 8% or less. The latent elastic sheet preferably has a maximum elongation of 10% or less (particularly 8% or less) in both the longitudinal direction and the width direction perpendicular thereto before being stretched. The elongation recovery rate and the maximum elongation are each measured by the following methods.

  When the latent elastic sheet becomes the elastic sheet 10 ′, the maximum elongation in the Y direction is 100% or more, and the elongation is recovered when it is contracted after being expanded to 100% in that direction. The rate (elongation recovery rate at 100% elongation) is preferably 70% or more. Here, “elongation 100%” refers to a state in which a sheet having a length of 50 mm is extended to 100 mm, for example. In addition, the latent stretchable sheet is preferably a sheet that can be stretched more in the Y direction than in the X direction when it becomes the stretchable sheet 10 ′. As an example of a preferred latent elastic sheet, in the case of the elastic sheet 10 ', in the Y direction, the film expands greatly and contracts after expansion (maximum elongation of 100% or more and elongation recovery rate at 100% elongation of 70). % Or more), but in the X direction, there is a sheet that extends only slightly (for example, a maximum elongation of 50% or less). The elongation recovery rate and the maximum elongation are each measured as follows.

[Method for measuring elongation recovery rate]
A sample piece having a length of 50 mm and a width of 25 mm is prepared. Using a Tensilon device, the sample piece is fixed at the chuck interval L0, and the length L2 at the time of 100% elongation at a speed of 300 mm / min (L2 = L0 × 2) Then, the length of the sample piece when the tensile load becomes 0 after starting to return at the same speed as the tensile speed is defined as the length L1 after the elongation recovery. The elongation recovery rate at 100% elongation is calculated from the following equation.
Elongation recovery rate at 100% elongation (%) = [(L2-L1) / (L2-L0)] × 100

[Measurement method of maximum elongation]
A sample piece having the same size as that of the sample piece used in the method for measuring the elongation recovery rate is elongated under the same conditions, and the elongation at the time of breaking is defined as the maximum elongation. The point of time of rupture is a point where the tensile load shows the maximum value in the relationship curve between the elongation rate and the load.

  As the latent stretchable sheet used in the present invention, various sheets that exhibit stretchability in a predetermined direction by stretching can be used, and a single layer structure or a multilayer structure in which a plurality of layers are laminated may be used. For example, (1) a sheet in which an extensible fiber layer is integrated on both sides or one side of an elastic fiber layer, and (2) an extensible fiber layer is integrated on both sides or one side of a net-like elastic sheet. (3) a sheet in which stretchable fiber layers are integrated on both sides or one side of an elastic sheet made of an elastic film, (4) a large number of sheets arranged to extend in one direction without crossing each other An elastic sheet or the like in which the elastic filament is bonded to a stretchable nonwoven fabric over the entire length thereof in a substantially non-stretched state can be preferably used. In addition, as an integration method of the elastic fiber layer and the extensible fiber layer, these are laminated and hydroentangled, or the fibers are entangled by air-through, etc., heat embossing, adhesive, ultrasonic wave The method of joining by etc. is mentioned. As the sheet (1), for example, a fiber sheet used as a material for the stretchable nonwoven fabric disclosed in Japanese Unexamined Patent Application Publication No. 2007-138374 and Japanese Unexamined Patent Application Publication No. 2008-179128 can be used.

  Further, a sheet (non-stretchable sheet) that is not a latent stretchable sheet may be used for the composite sheet 10. When using a non-stretchable sheet, a sheet in which elastic materials such as thread rubber, flat rubber, and elastic film are sandwiched between the non-stretchable sheets, or a sheet obtained by bonding a non-stretchable sheet and the above-described latent stretchable sheet Is used as the composite sheet 10. The non-stretch sheet is a sheet that is formed so that the stretch amount in a predetermined direction is increased by the stretching process of the present invention, and the extensibility in the predetermined direction is expressed. Nonwoven fabric, laminate material of nonwoven fabric and resin film, porous material A film etc. are mentioned.

  Next, the first embodiment of the elastic sheet manufacturing method for obtaining the elastic sheet 10 ′ by stretching the composite sheet 10 of the present invention is based on the elastic sheet manufacturing method using the processing apparatus 1. explain.

  In the manufacturing method of the stretchable sheet of the present invention, the composite sheet 10 is continuously supplied in the conveying direction (Y direction) to the meshing part of the pair of tooth groove rolls 2 and 3 meshing with each other, The composite sheet 10 is provided with a stretching process for imparting stretchability in the flow direction. In the stretching process, as shown in FIG. 1, the composite sheet 10 fed out from the original fabric (not shown) is continuously supplied to the meshing portion of the pair of tooth gap rolls 2 and 3, and is conveyed to the composite sheet 10 in the conveying direction (Y Direction). According to the tooth groove processing means 7 provided with the tooth groove rolls 2 and 3, the stretch ratio of the stretchable sheet 10 ′ obtained through the stretching step is preferably 50% or more and 400% or less (1.5 times or more and 5 or more). 0.0 times or less), more preferably 150% or more and 350% or less (2.5 times or more and 4.5 times or less), particularly preferably 200% to 300% (3.0 times or more and 4.0 times or less). Stretching at a draw ratio can be performed.

Here, the draw ratio is represented by the following formula (1).
Stretch ratio k = {(L′−L) / L} × 100 [%] (1)
L: Material length [mm] before being stretched by meshing of the tooth gap roll
L ′: material length [mm] after being stretched by engagement of the tooth gap roll
In addition, the number (times) in parentheses after the draw ratio (%) is expressed by the following formula (2), and the draw ratio is expressed by another expression.
Stretch ratio k ′ = (L′−L) / L + 1 [times] (2)

The stretchable sheet 10 ′ stretched to the stretching ratio by the tooth gap processing means 7 is applied with tension by the tension applying means 5 and 6 and is transported in the transport direction (Y direction). Therefore, there is a relationship of the following equation (3) between the rotational speed V1 of the feed rolls 51 and 52 of the tension applying means 5 and the rotational speed V2 of the feed rolls 61 and 62 of the tension applying means 6.
V2 = stretch ratio k ′ × V1 [m / min] (3)
Here, the rotation speed V1 of the feed rolls 51 and 52 and the rotation speed V2 of the feed rolls 61 and 62 of the tension applying means 6 mean speeds on the surfaces of the feed rolls 51, 52, 61, and 62.

Further, in order to stretch the composite sheet 10 by the tooth groove rolls 2 and 3 of the tooth groove processing means 7, the composite sheet 10 is supplied to the meshing portion of the teeth 21 of the tooth groove roll 2 and the teeth 31 of the tooth groove roll 3. There is a need to. Therefore, the rotational speed V3 of the tooth gap rolls 2 and 3 is related to the rotational speed V1 slower than the rotational speed V1 of the feed rolls 51 and 52 (V3 <V1), and the speed coefficient is represented by the following equation (4). Is done.
V3 = a × V1 [m / min] (4)
Here, the speed coefficient a is preferably 0.6 or more and 0.9 or less, particularly preferably 0.7 or more and 0.85 or less. In addition, the rotational speed V3 of the tooth gap rolls 2 and 3 is not the speed at the tips of the teeth 21 and 31, but the position entering from the tips of the teeth 21 and 31 to half of the meshing depth of the teeth 21 and 31. It is the speed at (half the position where adjacent teeth overlap).

  The method for producing an elastic sheet of the present invention controls the sheet width of the elastic sheet 10 ′ obtained by stretching as described above to a preset set width Wa, so that the elasticity obtained through the stretching process is obtained. A width detection step of detecting the width W of the sheet 10 ′, and based on the difference between the detected width W of the stretchable sheet 10 ′ and the preset width Wa of the stretchable sheet 10 ′, It has a control process for controlling the depth of meshing and / or the rotational speed of the pair of tooth space rolls 2 and 3. The width detection process and the control process will be specifically described below.

  In the width detecting step, the width detecting means disposed on the downstream side of the tooth gap processing means 7 is the sheet width W of the stretchable sheet 10 ′ obtained by drawing with the tooth gap rolls 2 and 3 of the tooth groove processing means 7. Detect with 4. More specifically, the sheet side edges 101, 102 in the conveying direction (Y direction) of the stretchable sheet 10 ′ obtained by stretching by the tooth gap processing means 7 (ends in the width direction (X direction) of the stretchable sheet 10 ′). The surface of the imaging area is imaged by the CCD camera 41 in a state where the imaging area including the edge is illuminated from the back side by the illuminator 42.

  In the first embodiment, the sheet width W of the stretchable sheet 10 ′ obtained by stretching is detected based on the position information image data of the sheet side edges 101 and 102 captured by the CCD camera 41. 43. Specifically, as shown in FIG. 2A, the imaging region 11 (width direction position x, length direction position y of the composite sheet 10) captured at a predetermined angle of view is the number of pixels of the CCD camera 41. For example, pixel data in the X direction in the imaging region 11 for any one pixel in the Y direction in the imaging region 11 is represented by a graph as shown in FIG. 2B. Is done. In FIG. 2B, the numerical value of the pixel data in the portion with the stretchable sheet 10 ′ that becomes dark as an image is small, and the numerical value of the pixel data is bright in the portion without the stretchable sheet 10 ′. A specific inspection area is provided for such an imaging area in order to detect the sheet side edges 101 and 102 of the stretchable sheet 10 '. In the processing apparatus 1 of the first embodiment, as shown in FIG. 2A, such an inspection area is divided into a left inspection area 111 and a right inspection area 112 corresponding to the sheet side edges 101 and 102, respectively. Separately provided.

  As shown in FIGS. 3A and 3B, pixel data in the X direction of both inspection areas 111 and 112 for one arbitrary pixel in the Y direction in both side inspection areas 111 and 112 are obtained, and both inspection areas are obtained. A graph of a number corresponding to the number of pixels in the Y-direction width of 111 and 112 (FIG. 3A and FIG. 3B is one of them) is averaged and differentiated, and FIG. ) And FIG. 3D, data conversion is performed so that the maximum and minimum values of the differential result become ± 100%. Then, position data of the sheet side edges 101 and 102 is obtained based on a threshold value set for specifying the sheet side edges 101 and 102. Then, the sheet width W of the stretchable sheet 10 ′ is calculated by subtracting the position data of the sheet side edge 101 from the position data of the sheet side edge 102. In the processing apparatus 1 of the present embodiment, during the conveyance of the stretchable sheet 10 ′, the above-described imaging and the calculation of the sheet width W are performed at predetermined intervals.

As described above, the manufacturing method of the stretchable sheet according to the present invention is based on the difference between the detected width W of the stretchable sheet 10 ′ and the set width Wa of the stretchable sheet 10 ′. There are a case where the rotational speed of the rolls 2 and 3 is controlled, a case where the depth of engagement of the meshing portions is controlled, and a case where both the rotational speed and the depth of meshing of the tooth gap rolls 2 and 3 are controlled.
First, a case where only the rotational speed of the tooth gap rolls 2 and 3 is changed so that the width W of the stretchable sheet 10 ′ obtained by the stretching process becomes a preset width Wa will be described.
The sheet width W data calculated from the position data of the sheet side edges 101 and 102 detected in the left inspection area 111 and the right inspection area 112 is transmitted from the image processing device 43 to the arithmetic processing unit 81 as shown in FIG. Is done. In the control step, the arithmetic processing unit 81 calculates the difference between the sheet width W of the stretchable sheet 10 ′ received from the image processing device 43 and the set width Wa of the stretchable sheet 10 ′ preset by the display / setting unit 9. Then, based on the difference from the set width Wa, the arithmetic processing unit 81 obtains a new rotational speed V3 ′ of the tooth gap rolls 2 and 3, and outputs an operation control command to the servo amplifier 83.

Specifically, the tooth gap rolls 2 and 3 are newly determined based on the deviation width ΔW (the following formula (5)) between the sheet width W of the stretchable sheet 10 ′ obtained by stretching and the preset set width Wa. The rotational speed V3 ′ is expressed by the following formula (6).
ΔW = {(W−Wa) / Wa} × 100 [%] (5)
W: Detection width [mm] of the stretchable sheet 10 ′ after being stretched
Wa: Preset width [mm]
V3 ′ = V3a−b × ΔW × V3a [m / min] (6)
V3a: standard speed of tooth gap rolls 2 and 3 [m / min]
b: Correction coefficient

  In the second term in the equation (6) of the new rotational speed V3 ′ of the tooth gap rolls 2 and 3, the sheet width W of the stretchable sheet 10 ′ is equal to the preset width Wa of the stretchable sheet 10 ′ ( (W = Wa) is a correction amount for the reference speed V3a, and is negative when the detected width W of the sheet after being stretched is larger than a preset set width Wa (W> Wa, ΔW> 0). When the detected width W of the sheet after being stretched is smaller than the preset set width Wa (W <Wa, ΔW <0), the value becomes a positive value. That is, the new rotation speed V3 ′ of the tooth gap rolls 2 and 3 is slower than the reference speed V3a when the sheet detection width W is larger than the set width Wa, and the sheet detection width W is smaller than the set width Wa. In this case, it is faster than the reference speed V3a. The data of the new rotation speed V3 ′ is transmitted from the arithmetic processing unit 81 to the servo amplifier 83, and the servomotor 71 rotates based on the rotation speed V3 ′, so that the stretchable sheet 10 ′ obtained by stretching is obtained. The sheet width is controlled to a preset setting width Wa. The reference speed V3a of the tooth gap rolls 2 and 3 refers to a speed for following (synchronizing) with the processing speed of the article manufacturing facility.

Next, the case where only the meshing depth of the tooth gap rolls 2 and 3 is changed so that the width W of the stretchable sheet 10 ′ obtained by the stretching process becomes a preset set width Wa will be described.
In the control step, the arithmetic processing unit 81 calculates the difference between the sheet width W of the stretchable sheet 10 ′ received from the image processing device 43 and the set width Wa of the stretchable sheet 10 ′ preset by the display / setting unit 9. Then, based on the difference from the set width Wa, the arithmetic processing unit 81 obtains a new meshing depth h ′ of the tooth gap rolls 2, 3 and outputs an operation control command to each of the servo amplifiers 85, 86.

Specifically, the new meshing depth h ′ is obtained from the deviation width ΔW (the following equation (5)) between the sheet width W of the stretchable sheet 10 ′ obtained by stretching and the preset set width Wa. Is expressed by the following equation (7).
h ′ = ha−c × ΔW × ha [mm] (7)
ha: Reference meshing depth [mm]
c: Correction coefficient The second term in the formula (7) of the new meshing depth h ′ of the tooth gap rolls 2 and 3 is the sheet width W of the stretchable sheet 10 ′ and the preset width of the stretchable sheet 10 ′. This is a correction amount for the reference meshing depth ha when Wa is equal (W = Wa), and when the detected width W of the sheet after being stretched is larger than a preset set width Wa (W> Wa, ΔW) > 0), similarly to the second term of the expression (6) of the new rotational speed V3 ′, the detected width W of the sheet after being stretched is the preset set width Wa. When it is smaller (W <Wa, ΔW <0), it becomes a positive value. That is, the new engagement depth h ′ is shallower than the reference engagement depth ha when the sheet detection width W is larger than the set width Wa, and when the sheet detection width W is smaller than the set width Wa, Deeper than the reference meshing depth ha. The data of the new meshing depth h ′ is converted into rotation data corresponding to the servomotors 74 and 75 that adjust the meshing depth of the tooth gap rolls 2 and 3, and the arithmetic processing unit 81 sends the data to the servo amplifiers 85 and 86. Sent. The servo amplifiers 85 and 86 rotate the servo motors 74 and 75 based on the rotation data, and the meshing depth adjustment units 72 and 73 connected to the servo motors 74 and 75 determine the meshing between the tooth gap rolls 2 and 3. By changing the depth to h ′, the sheet width of the stretchable sheet 10 ′ obtained by stretching is controlled to a preset set width Wa.

  Next, the width W of the stretchable sheet 10 ′ obtained by the stretching process becomes a preset set width Wa, and further, the stretchability of the sheet after the stretching process is kept constant so that the tooth gap rolls 2 and 3 are kept constant. A case where the rotational speed and the meshing depth are changed will be described. In order to control the width W of the stretchable sheet 10 ′ obtained by stretching so as to be a preset set width Wa, only the tooth groove rolls 2 and 3 are changed as described above. Or only the meshing depth of the tooth gap rolls 2 and 3 may be changed. However, if only the rotational speed of the tooth gap rolls 2 and 3 or the meshing depth is changed, the tension of the stretchable sheet 10 ′ after the stretching process is changed, so that the stretchability cannot be kept constant. For this reason, the rotational speed and the meshing depth of the tooth gap rolls 2 and 3 are simultaneously changed using the formula (6 ′) obtained by changing the second term of the formula (6) described above to the positive and the formula (7). To do.

Specifically, from the deviation width ΔW (formula (5) described above) between the sheet width W of the stretchable sheet 10 ′ obtained by stretching and the preset set width Wa, the tooth gap rolls 2, 3 The new rotational speed V3 ′ is expressed by the following equation (6 ′) in which the sign of the second term of the above-described equation (6) is changed to be positive, and the new meshing depth h ′ is expressed by the following equation (7) ).
V3 ′ = V3a + b × ΔW × V3a [m / min] (6 ′)
h ′ = ha−c × ΔW × ha [mm] (7)

  Data of the new rotation speed V3 'obtained by the above equation (6') is transmitted from the arithmetic processing unit 81 to the servo amplifier 83, and the servo motor 71 rotates based on the rotation speed V3 '. At the same time, the data of the new meshing depth h ′ obtained by the above formula (7) is converted into rotation data corresponding to the servomotors 74 and 75 for adjusting the meshing depth of the tooth gap rolls 2 and 3. Is transmitted from the arithmetic processing unit 81 to the servo amplifiers 85 and 86. The servo amplifiers 85 and 86 rotate the servo motors 74 and 75 based on the rotation data and adjust the meshing depth connected to the servo motors 74 and 75. By the portions 72 and 73, the meshing depth of the tooth gap rolls 2 and 3 is changed to h ′. In this way, by changing the rotation speed and the meshing depth of the tooth gap rolls 2 and 3, the sheet width of the stretchable sheet 10 'obtained by stretching is controlled to a preset set width Wa.

  As explained above, according to the elastic sheet manufacturing method of the first embodiment in which the elastic sheet having the set width Wa is manufactured using the processing device 1, the stretch detection step and the width detection step are provided, and the width detection is performed. Based on the difference between the width W of the stretchable sheet 10 ′ obtained by stretching detected in the process and the preset width Wa of the stretchable sheet 10 ′, the meshing portions of the pair of tooth space rolls 2 and 3 And / or a control step for controlling the rotational speed of the pair of tooth space rolls 2 and 3, the width of the sheet after stretching is maintained at the set width Wa, and further stretching is performed. A stretchable sheet 10 ′ in which the stretchability of the processed sheet is kept constant can be manufactured.

  In addition, according to the elastic sheet manufacturing method of the first embodiment in which the elastic sheet having the set width Wa is manufactured using the processing apparatus 1, the sheet width of the elastic sheet 10 ′ after stretching is detected in two dimensions. Therefore, the width of the stretchable sheet 10 ′ can be detected stably with high accuracy. Further, since the sheet width W of the stretchable sheet 10 ′ after the stretching process can be stably detected with high accuracy, the sheet width can be inspected.

  Moreover, according to the elastic sheet manufacturing method of the first embodiment in which the elastic sheet having the set width Wa is manufactured using the processing apparatus 1, the draw ratio as the processing condition of the composite sheet 10 and the standard sheet width If the data for each type of the reference meshing depth and the rotation speed of the standard tooth gap roll is stored in the arithmetic processing unit 81, the product type data can be easily obtained via the display / setting means 9. Can be switched.

  Next, the manufacturing method of the elastic sheet of this invention is demonstrated, referring drawings based on the preferable 2nd embodiment. FIG. 4 schematically shows a processing apparatus (hereinafter also simply referred to as a processing apparatus) used in the method for producing the stretchable sheet of the second embodiment. In the second embodiment, the description in detail regarding the first embodiment is appropriately applied to points that are not particularly described.

  As shown in FIG. 4, the processing apparatus 1 ′ of the second embodiment is further provided with a tension detection means 16 between the tooth gap processing means 7 and the width detection means 4. The processing apparatus 1 is the same as the processing apparatus 1 except for the tension detection means 16. That is, the processing apparatus 1 ′ controls the stretching process based on the width detection unit 4 and the tension detection unit 16.

  As shown in FIG. 4, the tension detection means 16 includes a tension detection roll 161, free rolls 162 and 163, and a tension detector 164. The tension detection roll 161 and the free rolls 162, 163 are arranged between the tooth gap rolls 2, 3 of the tooth gap processing means 7 and the width detection means 4. As shown in FIG. 4, the tension detection roll 161 is disposed between the upstream free roll 162 and the downstream free roll 163 and higher than the positions of the free rolls 162 and 163. The stretchable sheet 10 ′ obtained by stretching by the tooth gap processing means 7 is wound around the tension detection roll 161 in a Ω shape and conveyed to the tension detection roll 161 and the free rolls 162 and 163 arranged in this way. Therefore, the tension of the stretchable sheet 10 ′ is detected by the tension detection roll 161.

  Next, a second embodiment of the manufacturing method for manufacturing a stretchable sheet having a preset width according to the present invention will be described based on a stretchable sheet manufacturing method using the processing apparatus 1 '.

  The elastic sheet manufacturing method according to the second embodiment of the present invention has a change in the tension in the transport direction (Y direction) of the elastic sheet 10 ′ obtained through the stretching step between the stretching step and the width detecting step. It has a tension detection process to detect. In the control process of the second embodiment, when the detected variation in tension exceeds the set range, the preset width Wa of the stretchable sheet 10 ′ is set based on the variation in tension. change. More specifically, in the method for producing a stretchable sheet according to the second embodiment, in order to control the sheet width of the stretchable sheet 10 ′ obtained by stretching, the average value of the tension detected within a predetermined time is preset. When the tension becomes ± 120% or more with respect to the set tension of the stretchable sheet 10 ′, a new set width Wat is set based on the fluctuation of the tension, and based on the result, the meshing portion meshes. And / or a control step of controlling the rotational speed of the pair of tooth space rolls 2 and 3.

  In the tension detection step, the stretchable sheet 10 ′ obtained by stretching by the tooth gap processing means 7 has a constant tension in a Ω shape between the tension detection roll 161 that is the tension detection means 16 and the free rolls 162 and 163. The tension detection roll 161 detects the tension of the stretchable sheet 10 ′ that is continuously conveyed and stretched. As shown in FIG. 4, the tension detected by the tension detection roll 161 is transmitted to the tension detector 164 as an analog signal and converted into tension data, and the calculation processing unit 81 outputs an operation control command of the control means 8. Sent. A tension meter or the like is used to detect the tension.

  In the control step, the arithmetic processing unit 81 calculates a difference ΔT between the tension T of the stretchable sheet 10 ′ received from the tension detector 164 and the set tension Ta of the stretchable sheet 10 ′ preset by the display / setting means 9. When the average tension value detected within a predetermined time is equal to or greater than ± 120% of the preset tension of the stretchable sheet 10 ′, a calculation process is performed based on the difference from the preset tension Ta. In the part 81, a new rotational speed V3t and a new meshing depth ht of the tooth gap rolls 2 and 3 are obtained, and an operation control command is output to each of the servo amplifiers 83, 85 and 86.

Specifically, from the difference ΔT (the following formula (8)) with the set tension Ta, a new set width Wat of the stretchable sheet 10 ′, a deviation ΔWt from the detected width W of the stretched sheet, and roll 2 , 3 are represented by the following equations (9, 10, 11), respectively.
ΔT = {(T−Ta) / Ta} × 100 [%] (8)
T: Tension of the stretchable sheet 10 ′ after being stretched (average value within a predetermined time)
Ta: Preset tension set Wat = Wa + d × ΔT × Wa [mm] (9)
Wa: Preset width [mm]
d: Correction coefficient ΔWt = {(W−Wat) / Wat} × 100 [%] (10)
W: Detection width [mm] of the stretchable sheet 10 ′ after being stretched
V3t ′ = V3a−b × ΔWt × V3a [m / min] (11)
V3a: Reference speed of rolls 2 and 3 [m / min]
b: Correction coefficient

  The second term in the above equation (9) is a correction amount with respect to a preset setting width Wa, and the tension data of the stretchable sheet 10 ′ after being stretched is set tension data as in the above equation (8). When larger (T> Ta), ΔT becomes a positive value, and the new set width Wat becomes larger than the initial set width Wa (Wat> Wa) by the above equation (9). Here, it is generally known that when the tension (tension data) is large, the detection width W of the stretchable sheet 10 ′ after being stretched is small. Therefore, the difference (W−Wat) between the detected width W of the stretched sheet and the new set width Wat shown in the above equation (10) is relatively small (negative value). The new rotational speed V3t ′ of the tooth gap rolls 2 and 3 shown in 11) is increased. When the average value of the tension detected within a certain time becomes + 120% or more of the preset tension of the stretchable sheet 10 ′, the data of the new rotation speed V3t ′ is calculated. The tension of the stretchable sheet 10 ′ can be controlled to be small by rotating the servo motor 71 based on the rotation speed V3t ′.

  On the other hand, when the tension data of the stretchable sheet 10 ′ after being stretched is smaller than the set tension data (T <Ta) as in the above formula (8), ΔT becomes a negative value, and the above formula (9 ), The new set width Wat becomes smaller than the initial set width Wa (Wat <Wa). Therefore, the detected width W of the sheet after being stretched and the new set width Wat shown in the above equation (10) Difference (W−Wat) becomes relatively large (positive value), and the new rotation speed V3t ′ of the tooth gap rolls 2 and 3 shown in the above equation (11) becomes slow. When the average value of the tension detected within a certain time becomes a tension of −120% or more with respect to the preset tension of the stretchable sheet 10 ′, the data of the new rotation speed V3t ′ is calculated. By transmitting the servo motor 71 from the processing unit 81 to the servo amplifier 83 and rotating based on the rotational speed V3t ′, the tension of the stretchable sheet 10 ′ can be largely controlled.

The new meshing depth ht ′ is expressed by the following equation (12).
ht ′ = ha−e × ΔWt × ha [mm] (12)
ha: Reference meshing depth [mm]
e: Correction coefficient The second term in the above equation (12) is a correction amount for the reference meshing depth ha, and when the tension data of the stretchable sheet 10 ′ after being stretched is larger than the set tension data (T> Ta ), ΔT in the above equation (8) is a positive value, so the new set width Wat shown in the above equation (9) is larger than the initial set width Wa (Wat> Wa). Therefore, the difference (W−Wat) between the detected width W of the stretched sheet and the new set width Wat shown in the above equation (10) is relatively small (negative value). The new meshing depth ht ′ shown in 12) is increased. When the average value of the tension detected within a predetermined time is + 120% or more of the preset tension of the stretchable sheet 10 ′, the data of the new meshing depth ht ′ is It is transmitted from the arithmetic processing unit 81 to the servo amplifiers 85 and 86. The servo amplifiers 85 and 86 rotate the servo motors 74 and 75 based on the rotation data, and the meshing depth adjusting units 72 and 73 connected to the servo motors 74 and 75 determine the meshing between the tooth gap rolls 2 and 3. By changing to ht ′ having a large depth, the tension of the stretchable sheet 10 ′ can be controlled to be small.

  On the other hand, when the tension data of the stretchable sheet 10 ′ after being stretched is smaller than the set tension data (T <Ta), ΔT in the above equation (8) is a negative value, so the above equation (9) Is smaller than the initial setting width Wa (Wat <Wa). Therefore, the detected width W of the sheet after being stretched and the new setting width Wat shown in the above equation (10) The difference (W−Wat) becomes relatively small (negative value), and the new meshing depth ht ′ shown in the above equation (12) becomes small. When the average value of the tension detected within a certain time becomes a tension of −120% or more with respect to the preset tension of the stretchable sheet 10 ′, the data of the new meshing depth ht ′ is It is transmitted from the arithmetic processing unit 81 to the servo amplifiers 85 and 86. The servo amplifiers 85 and 86 rotate the servo motors 74 and 75 based on the rotation data, and the meshing depth adjustment units 72 and 73 connected to the servo motors 74 and 75 determine the meshing between the tooth gap rolls 2 and 3. By changing to ht ′ having a small depth, the tension of the stretchable sheet 10 ′ can be largely controlled.

  As described above, when the average value of the tension detected within a certain time becomes a tension of ± 120% or more with respect to the preset tension of the stretchable sheet 10 ′, the tension detected within the certain time Based on the average value and preset preset tension, a new preset width Wat is set within a range in which the sheet width after stretching is not greatly changed (preferably within ± 5 mm of the initial set width Wa, particularly preferably within ± 3 mm). By calculating and adjusting the rotational speed and / or the meshing depth of the tooth gap rolls 2 and 3, the tension of the stretchable sheet 10 ′ after stretching is controlled. In addition, when the average value of the tension detected within a certain time is within ± 120% of the preset tension of the stretchable sheet 10 ′, the stretchable sheet according to the first embodiment is manufactured. Similarly to the method, based on the difference between the width W of the stretchable sheet 10 ′ after being stretched and the preset width Wa of the stretchable sheet 10 ′, the pair of tooth gap rolls 2 and 3 is engaged. The depth of engagement of the parts and / or the rotational speed of the pair of tooth space rolls 2 and 3 are controlled.

  As explained above, according to the elastic sheet manufacturing method of the second embodiment in which the elastic sheet of the set width Wa is manufactured using the processing apparatus 1 ′, the elastic sheet manufacturing method of the first embodiment is used. On the other hand, a tension detecting step is further provided, and the stretching process is controlled by detecting the width and tension of the stretchable sheet 10 ′ after the stretching process. Sheet 10 'can be manufactured stably. In particular, when the tension data detected by the tension detecting means 16 is greatly fluctuated, the tension fluctuation can be reduced by controlling the rotational speed and the meshing depth of the tooth gap rolls 2 and 3. A stretchable sheet 10 ′ having stretchability can be stably produced.

  Moreover, according to the elastic sheet manufacturing method of the second embodiment for manufacturing the elastic sheet of the set width Wa using the processing apparatus 1 ′, the tension of the elastic sheet 10 ′ after the stretching process can be detected. Abnormalities in the composite sheet can be easily detected.

  Next, the manufacturing method of the underpants type wearing article of this invention is demonstrated based on the preferable embodiment applied to the manufacturing method (henceforth a diaper manufacturing method) of a pants type disposable diaper.

  As shown in FIG. 5, the manufacturing method of the diaper of this embodiment uses the elastic sheet (sheet obtained by stretching the composite sheet 10) 10 ′ manufactured by the elastic sheet manufacturing method. The diaper 30 is manufactured and can be manufactured in the same manner as a conventional so-called cross-flow type pants-type disposable diaper except that a continuous body of the stretchable sheet 10 ′ is used.

  The manufacturing method of the diaper of this embodiment includes the step of forming a continuous body of the outer packaging material 20 including the stretchable sheet 10 ′ obtained by stretching, and the absorption of arranging the absorbent main body 21 in the continuous body of the outer packaging material 20. The disposing step of the absorbent main body 21, the leg hole forming step of forming the leg hole 22 in the continuous body of the outer packaging material 20, and the continuous body of the outer packaging material 20 in which the absorbent main body 21 is disposed together with the absorbent main body 21 in the transport direction A folding step of folding the outer packaging material 20 along the longitudinal direction, a joining step of joining the continuous body of the outer packaging material 20 folded in half at a predetermined interval in the length direction, and joining the continuous body of the outer packaging material 20 And a separation step of cutting the separated portions and separating them individually.

  In the process of forming the continuous body of the outer packaging material 20, the stretchable sheet 10 ′ obtained by performing the stretching process as the outer layer sheet to be included in the outer packaging material 20 and the inner layer sheet 23 arranged on the skin side are joined to each other. A continuous body of the material 20 is formed. In this embodiment, when these sheets are joined together, the waist elastic member 24 and the leg elastic member 25 are also supplied between these sheets and joined in an expanded state between them. Specifically, an adhesive for fixing the waist elastic member 24 and the leg elastic member 25 to a predetermined part of one or both opposing surfaces of the two sheets before the two sheets are overlaid. In a state where these elastic members are sandwiched in an expanded state, both belt-like sheets are narrowed and fixed by the nip roll 17.

  Between the stretchable sheet 10 ′ obtained by stretching and the inner layer sheet 23, when the inner layer sheet 23 does not have stretchability or stretchability, the ventral side portion, the back side portion of the diaper 30, and It is preferable that most of the crotch portions are not joined. Specifically, the stretchable sheet 10 ′ and the inner layer sheet 23 obtained by stretching are heat sealed, high-frequency sealed, or ultrasonically sealed at both side edges of the stomach side and back side of the diaper 30. Are joined to each other by an adhesive such as a hot melt adhesive at the periphery of the waist opening and the periphery of each of the pair of leg holes. It joins in the center part of each diaper width direction. And it is preferable that it is not joined in parts other than those. When the inner layer sheet 23 is stretchable or stretchable, the inner layer sheet 23 is stretched and joined to the stretchable sheet 10 'that has been stretched in the same stretched state. Alternatively, it may be partially joined.

  As the inner layer sheet 23, a sheet having extensibility or stretchability in the longitudinal direction is preferably used. The maximum elongation in the longitudinal direction of the inner layer sheet 23 is preferably 100% or more. As the sheet having extensibility in the longitudinal direction but not stretchable, those described in JP-T-8-508789, JP-T 2000-513054 and the like can be used. Similarly, the inner layer sheet 23 may be a stretchable sheet, such as the stretchable sheet 10 ′ obtained by stretching with the above-described tooth gap rolls 2 and 3. Also, as described in the specification [0021] to [0027] at the beginning of the application of Japanese Patent Application No. 2006-207596, the stretched first belt-like sheet and the substantially non-stretched second belt-like sheet are attached. Combined sheets can also be used. When a sheet having stretchability is used for the inner layer sheet 23, there is no particular limitation, but for example, a sheet that exhibits stretchability by stretching as in the stretchable sheet 10 'is preferably used.

  The waist elastic member 24 is supplied to both side portions of the outer packaging material 20 so as to be positioned at the waist portion of the diaper, and is bonded and fixed with an adhesive. The leg elastic member 25 is supplied in accordance with the shape of the leg hole 22 and the crotch part to be formed later, and is joined and fixed with an adhesive. The leg elastic member 25 is a belt-like sheet while being swung by a known rocking guide (not shown) in a direction perpendicular to the flow direction of the stretchable sheet 10 ′ and the inner layer sheet 23 obtained by stretching. Introduced between. As the waist elastic member 24 and the leg elastic member 25, ordinary members conventionally used for this type of article can be employed. As the waist elastic member 24 and the leg elastic member 25, elastic materials such as natural rubber, polyurethane resin, foamed urethane resin, hot melt elastic member, etc. are made into a thread shape (thread rubber) or a belt shape (flat rubber), respectively. Those formed in the above are preferably used.

  In the arrangement process of the absorbent main body 21, the absorbent main body 21 to which an adhesive such as a hot melt adhesive is applied in advance is rotated 90 degrees and intermittently supplied onto the inner layer sheet 23 of the continuous body of the outer packaging material 20. Fixed.

  The absorbent main body 21 has a substantially vertically long form having a liquid-permeable top sheet, a liquid-impermeable or water-repellent back sheet, and a liquid-retaining absorbent core interposed between the two sheets. is doing. For these topsheet, backsheet and absorbent core, those similar to those conventionally used for this type of article are employed. For example, the absorbent core is made of a superabsorbent polymer particle and a fiber material and is covered with a tissue paper (not shown).

  In the leg hole forming step, the leg hole 22 is formed inside the annular portion of the leg elastic member 25 in the continuous body of the outer packaging material 20 in which the absorbent main body 21 is arranged. For the formation of the leg hole 22, a technique similar to the technique in the conventional manufacturing method of this type of article such as a rotary cutter and a laser cutter is employed. The leg hole can be formed before the absorbent main body 21 is arranged.

  In the folding step, both the side edges of the continuous body of the outer packaging material 20 are folded in advance so as to be folded at both ends in the length direction of the waist elastic member 24 and the absorbent main body 21, and then the continuous body of the outer packaging material 20 The absorbent main body 21 is folded in half along the transport direction (Y direction).

  In the joining step, the continuous body of the outer packaging material 20 folded in two with the absorbent main body 21 is joined at a predetermined interval in the length direction, and a joining portion 26 corresponding to the side seal portion of the diaper is formed. For the formation of the joint portion 26, a technique similar to the technique in the conventional manufacturing method of this type of article such as heat sealing, ultrasonic sealing, high frequency sealing, and adhesive is conventionally employed.

  In the separation step, the continuous body is cut and separated into individual diapers 30 at a substantially central portion of the joint portion 26 of the continuous body of the outer packaging material 20 formed in the joining step. For the separation of the diaper 30, a method similar to the method in the manufacturing method of this type of article is conventionally employed.

  As explained above, according to the manufacturing method of the diaper of the present embodiment, by controlling the processing conditions such as the tooth engagement depth between the tooth gap rolls 2 and 3 and the rotation speed of the tooth gap rolls 2 and 3, stretching is performed. Suppresses fluctuations in the sheet width after stretching due to fluctuations in tension during sheet conveyance before processing and fluctuations in sheet basis weight before stretching, etc., and the sheet after stretching is controlled with high accuracy while maintaining the required stretchability. In addition, since a sheet having a required width can be supplied to the manufacturing apparatus, a pants-type wearing article having excellent fit and high completeness can be stably manufactured.

  Moreover, according to the manufacturing method of the diaper of this embodiment, when changing the type of the pants-type wearing article or changing the product specification, the draw ratio (the rotation speed set value of the feed roll after the drawing process is set to the feed before the drawing process). Simply switch the data of the roll rotation speed setting value), the reference sheet width, the reference engagement depth, and the reference tooth gap roll rotation speed, and the required width is required. It is possible to easily supply a sheet having a stretchability to a diaper manufacturing apparatus.

  Moreover, according to the manufacturing method of the diaper of this embodiment, the detector for detecting the sheet width after stretching has a wide inspection field even if the sheet width is changed by changing the type of article for wearing pants. The adjustment of the apparatus accompanying the size change of the pants-type wearing article is unnecessary, and the convenience is not impaired. .

The present invention is not limited to the above embodiment.
For example, in the processing apparatus 1 of the first embodiment, an optical imaging device is used as the width detection unit 4, but the width detection unit 4 may be a line sensor (one-dimensional), a laser sensor, A photoelectric sensor may be used.

  In the processing apparatus 1 of the first embodiment, the arithmetic processing unit 81 and the servo amplifiers 82, 83, 84, 85, 86 are used as the control means 8, but one arithmetic processing unit having these functions is used. Can also be replaced.

  The present invention can also be applied to sheet processing other than the manufacturing apparatus for a pants-type wearing article as in the above embodiment.

DESCRIPTION OF SYMBOLS 1 Processing apparatus 2 Tooth groove roll 21 Tooth 3 Tooth groove roll 31 Tooth 4 Detection means 41 CCD camera (imaging device)
42 Illuminator 43 Image Processing Device 5 Tension Applying Unit 51, 52 Feed Roll 53 Servo Motor 6 Tension Applying Unit 61, 62 Feed Roll 63 Servo Motor 7 Tooth Groove Processing Unit 71 Servo Motor 72, 73 Engagement Depth Adjustment Unit 74, 75 Servo motor 8 for adjusting the meshing depth 8 Control means 81 Arithmetic processing section 82, 83, 84, 85, 86 Servo amplifier 9 Display / setting means 10 Composite sheet 10 'Elastic sheet obtained by subjecting composite sheet 10 to stretching 101, 102 Sheet side edge 11 in the conveyance direction (Y direction) of the elastic sheet 10 ′ Imaging area 111 Left inspection area 112 Right inspection area 15 Free roll 16 Tension detection means 161 Tension detection roll 162, 163 Free roll 164 Tension detector 17 Nip roll 20 Outer packaging material 21 Absorbent body 2 Leg hole 23 Inner layer sheet 24 Waist elastic member 25 Leg elastic member 26 Joint 30 Diaper V1 Rotational speed V2 of feed rolls 51 and 52 Rotational speed V3 of feed rolls 61 and 62 Rotational speed Wa of tooth gap rolls 2 and 3 beforehand Set width W of the stretchable sheet that has been set Detected width of the stretchable sheet after being stretched by the tooth groove roll

Claims (6)

A method for producing a stretchable sheet, which is obtained by stretching a composite sheet to obtain a stretchable sheet,
A stretching process for continuously supplying a composite sheet to a meshing portion of a pair of tooth groove rolls that mesh with each other in the conveying direction and imparting stretchability to the composite sheet between the pair of tooth groove rolls;
A width detection step for detecting the width of the elastic sheet obtained through the stretching step;
Based on the difference between the detected width of the stretchable sheet and a preset set width of the stretchable sheet, the meshing depth of the meshing portion and / or the rotational speed of the pair of tooth groove rolls is determined. The manufacturing method of the elastic sheet which has a control process to control.   The method for producing a stretchable sheet according to claim 1, wherein, in the width detection step, the width of the stretchable sheet is detected based on pixel data obtained by imaging the stretchable sheet.   The stretchable sheet according to claim 1, further comprising a tension detection step of detecting a change in tension in the transport direction of the stretchable sheet obtained through the stretching step between the stretching step and the width detection step. Manufacturing method.   The expansion and contraction according to claim 3, wherein, in the control step, when the detected variation in the tension exceeds a set range, the preset setting range is changed based on the variation in the tension. Manufacturing method of adhesive sheet. It is a manufacturing method of the underpants type wearing article using the elastic sheet manufactured with the manufacturing method according to claim 1,
A folding step of folding the continuous body of the exterior material including the stretchable sheet in half along the transport direction, and a joining step of joining the continuous body folded in half at a predetermined interval in the transport direction And a separation step of separating the individual continuous bodies by cutting them at the joints. A sheet processing method for continuously supplying a composite sheet to a meshing portion of a pair of tooth gap rolls that mesh with each other in a conveying direction, and processing the composite sheet into an elastic sheet having a required width,
The width of the stretchable sheet is detected on the downstream side of the tooth gap roll, and based on the difference between the detected width and the required width, the meshing depth of the meshing portion and / or the pair of tooth groove rolls Sheet processing method for controlling the rotation speed of the sheet.

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