JP5866482B1 - Drying apparatus and drying method - Google Patents

Abstract

An object of the present invention is to quickly dry a sheet that constitutes an absorbent article and has an inkjet printed image. This invention is a drying apparatus (50) of the sheet | seat (9A) which comprised the absorbent article and inkjet-printed the image (G). The drying device (50A, 50B) is provided inside the drying chamber (51A, 51B) and the drying chamber, and conveys the sheet (9A) by rotating while holding the sheet (9A) on the outer peripheral surface. And a sheet supply unit that supplies the sheet (9A) to the outer peripheral surface of the drum (52A, 52B) so that the printing surface of the sheet (9A) faces outward.

Description

  The present invention relates to a drying apparatus and a drying method.

  A disposable diaper (hereinafter simply referred to as “diaper”) is an example of an absorbent article that absorbs liquid (body fluid) excreted from the human body. In order to improve the appearance design of diapers and to make it easy to distinguish the front and back of the diaper at a glance, images such as patterns and characters are attached to the diaper exterior member. For example, Patent Document 1 describes a diaper in which a predetermined color design is printed on the entire area of an interior sheet (base material sheet) that covers the back surface of the diaper.

  When manufacturing a diaper with an image, it is common to use a printing sheet on which an image has been printed in advance. On the other hand, Patent Document 2 describes that an ink jet printing process is incorporated on a diaper production line.

JP 2003-70838 A JP 2008-516807 A

  When ink jet printing is performed on a sheet (for example, a nonwoven fabric) constituting a diaper, if the ink droplets are small, the ink droplets may pass between the fibers of the sheet, and the print density may be insufficient. For this reason, when inkjet printing is performed on a sheet constituting a diaper, relatively large ink droplets are ejected. On the other hand, when ink jet printing is performed with large ink droplets, the amount of ink adhering to the sheet increases, and thus there is a problem that drying tends to be insufficient. For this reason, when an inkjet printing process is incorporated on the diaper production line, it is required to efficiently dry the ink attached to the sheet.

  An object of the present invention is to quickly dry a sheet that constitutes an absorbent article and has an inkjet printed image.

A main invention for achieving the above object is a sheet drying apparatus that constitutes an absorbent article and has an image printed thereon, and is provided in a drying chamber and the drying chamber. A drum that conveys the sheet by rotating while being held; and a sheet supply unit that supplies the sheet to the outer peripheral surface of the drum so that a printing surface of the sheet faces outside. An air outlet that blows out the drying air is provided at an opposing position, and a vent hole is formed in the outer peripheral surface of the drum, and the drying air is passed through the vent hole in the thickness direction of the sheet , Another drum for further drying the passed sheet is provided, and the sheet is semi-dried in a conveyance path between the drum and the other drum. A roller for changing the conveyance direction of the sheet, and the other drum further holds the sheet while conveying the sheet so that the printing surface of the sheet faces outward. The drying apparatus is characterized by drying.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  ADVANTAGE OF THE INVENTION According to this invention, the absorbent article can be comprised and the sheet | seat which has the image by which inkjet printing was carried out can be dried rapidly.

FIG. 1A is a perspective view of a pant-type diaper 1. FIG. 1B is a plan view of the unfolded diaper 1 as seen from the skin side. FIG. 2 is an exploded explanatory view of the diaper 1 in the unfolded state. FIG. 3 is a side view of the production line LM for the exterior sheet 7. 4A and 4B are explanatory diagrams of the ink jet printing apparatus 20. FIG. 5 is an explanatory diagram of the image G before and after contraction. FIG. 6 is an explanatory diagram of the configuration of the linear conveyance type drying apparatus 40. FIG. 7 is a cross-sectional view of the air outlet 43. FIG. 8 is a configuration diagram of the drum-type drying device 50. FIG. 9A is an explanatory diagram of a cross-sectional structure of the outer peripheral surface of the first drum 52A. FIG. 9B is an explanatory diagram of the metal plate 521. FIG. 9C is an explanatory diagram of the mesh member 522. FIG. 10 is a process explanatory diagram from the generation of the exterior continuous sheet 7A to the completion of the diaper 1. FIG. 11 is an explanatory diagram of the print drying apparatus 11 according to the second embodiment. FIG. 12 is an explanatory diagram of the belt conveyance device 46.

  At least the following matters will become apparent from the description of the present specification and the accompanying drawings.

  A drying apparatus for a sheet constituting an absorbent article and inkjet-printed with an image, provided in a drying chamber and the drying chamber, and transporting the sheet by rotating while holding the sheet on an outer peripheral surface And a sheet supply unit that supplies the sheet to the outer peripheral surface of the drum so that the printing surface of the sheet faces outward. According to such a drying apparatus, it is possible to quickly dry a sheet having an absorbent article and having an inkjet printed image.

  Ventilation holes are formed in the outer peripheral surface of the drum, and it is preferable that drying air is passed through the ventilation holes in the thickness direction of the sheet. As a result, the ink that has penetrated into the sheet can be quickly dried.

  The sheet supply unit preferably supplies the sheet to the outer peripheral surface of the drum in a state where a predetermined tension is applied, and allows the drying air to pass in the thickness direction of the sheet to which the tension is applied. By applying tension, voids between the fibers widen, so that drying can be promoted.

  It is desirable to provide an air outlet for blowing out the drying air at a position facing the outer peripheral surface. This facilitates the passage of drying air in the thickness direction of the sheet.

  The width of the air outlet in the sheet conveying direction is preferably narrower than the width of the vent hole in the sheet conveying direction. This facilitates the passage of drying air in the thickness direction of the sheet.

  It is desirable that the sheet is wound around the outer peripheral surface equal to or more than a half circumference of the drum. Thereby, a long drying section can be secured.

  It is desirable to provide another drum for further drying the sheet that has passed through the drum. Thereby, a drum can be reduced in size, ensuring a dry area.

  After the sheet is semi-dried while transporting the sheet by the drum, a roller is brought into contact with the printing surface of the sheet to change the transport direction of the sheet, while the sheet is transported by the other drum It is desirable to further dry the sheet. Thereby, even if the printing surface of a sheet contacts a roller when changing the conveyance direction of the sheet, ink contamination of the roller can be suppressed.

  The roller is preferably disposed outside the drying chamber. Thereby, while being able to miniaturize a drying chamber, it can suppress that the surface of the roller which contacts a printing surface becomes high temperature.

  It is desirable that the roller rotate at a rotation speed corresponding to the sheet conveyance speed. Thereby, the ink contamination of a roller can further be suppressed.

  After the sheet is heated and dried inside the drying chamber, it is preferable that the sheet is conveyed in a direction different from the conveying direction of the sheet in the drying chamber along a path along the drying chamber. Thereby, size reduction of a drying apparatus can be achieved, lengthening the cooling zone of the sheet | seat after heat drying.

  A method for drying a sheet comprising an absorbent article and inkjet-printed with an image, wherein the sheet is supplied to an outer peripheral surface of a drum provided in a drying chamber so that the printed surface of the sheet faces outward And a drying method of conveying the sheet by rotating the drum while holding the sheet on the outer peripheral surface of the drum. According to such a drying method, it is possible to quickly dry a sheet that constitutes an absorbent article and that has an inkjet printed image.

=== First Embodiment ===
First, a basic structure of a pants-type diaper 1 (hereinafter simply “diaper 1”) will be described as an example of an absorbent article, and then a production line LM including an inkjet printing process and a drying process will be described.

<Basic structure of diaper 1>
FIG. 1A is a perspective view of a pant-type diaper 1. FIG. 1B is a plan view of the unfolded diaper 1 as seen from the skin side. FIG. 2 is an exploded explanatory view of the diaper 1 in the unfolded state. In the following description, the side that should be positioned on the skin side of the wearer may be referred to as “skin side”, and the side that should be positioned on the non-skin side of the wearer may be simply referred to as “non-skin side”. .

  The diaper 1 is a so-called two-piece type diaper. The diaper 1 has an absorbent main body 3 and an exterior sheet 7. The absorptive main body 3 is a member that absorbs excreted fluid such as urine. The exterior sheet 7 is a member having an approximately hourglass shape in plan view, and is disposed so as to cover the non-skin side surface of the absorbent main body 3 and serves as an exterior of the diaper 1.

  As shown in FIG. 2, the absorbent main body 3 is joined at the joint portion J on the skin side of the exterior sheet 7. Moreover, as shown to FIG. 1B, the exterior sheet | seat 7 which joined the absorptive main body 3 is folded in half, and is each joined by each edge part of the width direction. Thereby, as shown to FIG. 1A, the trunk periphery opening part HB and a pair of leg periphery opening part HL are formed.

  As shown in FIG. 2, the exterior sheet 7 is a composite sheet in which an inner layer sheet 8 and an outer layer sheet 9 are joined. The inner layer sheet 8 is a sheet that forms an inner layer facing the wearer's skin side. The outer layer sheet 9 is a sheet that forms an outer layer facing the non-skin side when worn.

  As the material of the inner layer sheet 8, an elastic sheet having elasticity in the width direction of the diaper 1 is used. The term “stretchability” refers to the property that when an external force of tension is applied, it stretches approximately elastically in the direction of the external force and contracts approximately elastically when the external force is released. Since the stretchable sheet is configured in a state where a plurality of fibers are randomly intertwined, when viewed microscopically, it has a structure having a plurality of voids between the fibers. On the surface of the elastic sheet, there are a portion where fibers are intertwined closely and a portion where fibers are intertwined roughly. That is, the inner layer sheet 8 (elastic sheet) has a structure having roughness. For this reason, even when both ends of the inner layer sheet 8 are gripped equally in the lateral direction and pulled in the longitudinal direction, the entire region in the lateral direction does not extend evenly, and the density is partially large. Thus, a portion where the gap becomes large may occur.

  As the material for the outer layer sheet 9, a low extensible sheet having low extensibility in the width direction of the diaper 1 is used. The “low extensibility sheet” is an extensibility sheet lower than the stretchable sheet (inner layer sheet 8). That is, the outer layer sheet 9 (low extensible sheet) has an elongation rate (%) when a tensile external force of a predetermined size is applied, which is lower than the elongation rate (%) of the inner layer sheet 8 (elastic sheet). It is a sheet. “Elongation rate (%)” means that the length of the belt-like sheet when pulled by an external force of 1.0 (N) is L1, and the length of the belt-like sheet at no load before being pulled is L0 ( L1-L0) / L0 as a percentage.

  The inner layer sheet 8 (elastic sheet) and the outer layer sheet 9 (low extensible sheet) are made of nonwoven fabric. However, the inner layer sheet 8 and the outer layer sheet 9 may be other sheets such as a woven fabric, for example. As will be described later, the outer layer sheet 9 on which the image G is inkjet printed is a sheet through which drying air can pass in the thickness direction. The nonwoven fabric is included in a sheet through which drying air can pass in the thickness direction.

  Low stretchability in a state where the stretchable inner layer sheet 8 is stretched in the width direction at a predetermined stretch ratio (for example, 2.5 times the natural length) (hereinafter, “stretched state”). The outer layer sheet 9 is laminated. When the stretched state is released, the inner layer sheet 8 contracts in the width direction of the diaper 1, and the low-stretch outer layer sheet 9 bends in the width direction of the diaper 1 so as to form a plurality of wrinkles. As a result, in an unloaded state where no external force is applied to the diaper 1, the outer surface of the exterior sheet 7 is in a state where a plurality of wrinkles are offset.

  In the diaper 1 of the present embodiment, an image G composed of predetermined characters, patterns, characters, and the like is printed on the exterior sheet 7 (see FIG. 1A). The image G improves the design on the appearance of the diaper 1 and enables the user to visually recognize information about the diaper 1 (for example, information indicating the product name and the front and back of the diaper 1).

<Method for manufacturing exterior sheet 7>
FIG. 3 is a side view of the production line LM for the exterior sheet 7. The printing drying apparatus 11 of the production line LM in the figure performs inkjet printing of the image G on the continuous sheet 9A of the outer layer sheet 9 (hereinafter referred to as outer layer continuous sheet 9A), and dries the outer layer continuous sheet 9A having the inkjet printed image G. By doing so, the outer-layer continuous sheet 9A which comprises the diaper 1 is manufactured. The print drying apparatus 11 includes an inkjet printing apparatus 20 and a drying apparatus 30 (a linear conveyance drying apparatus 40 and a drum type drying apparatus 50). The production line LM is controlled by the main controller 12, and the ink jet printing apparatus 20 and the drying apparatus 30 of the print drying apparatus 11 are controlled by the main controller 12.

  In the following description, the conveyance direction of each sheet (outer layer continuous sheet 9A and inner layer continuous sheet 8A) of the production line LM may be referred to as “MD direction”. The MD direction can be different depending on the type of the sheet, and even the same sheet can be different depending on the conveyance place. In addition, a direction parallel to the width direction of each sheet may be referred to as a “CD direction”. The CD direction is an in-plane direction of the sheet and a direction perpendicular to the MD direction, and is a direction perpendicular to the paper surface of FIG. The CD direction corresponds to the longitudinal direction of the diaper 1 (see FIG. 1B). In addition, a direction parallel to the thickness direction of each sheet may be referred to as a “Z direction”. The Z direction is a direction perpendicular to the MD direction and the CD direction.

Inkjet printing device 20
4A and 4B are explanatory diagrams of the ink jet printing apparatus 20. FIG. 4A is a side view of the inkjet printing apparatus 20. FIG. 4B is an explanatory diagram of the head unit 21 of the inkjet printing apparatus 20.
The inkjet printing apparatus 20 is an apparatus that ejects ink droplets from a large number of nozzles Nz and forms an image G on the outer layer continuous sheet 9A by ink (dots) attached to the outer layer continuous sheet 9A. The ink jet printing apparatus 20 includes a head unit 21, a transport roller 23, and a print control unit 24. In the following description, the surface on the head unit 21 side of the outer layer continuous sheet 9A may be referred to as a “printing surface”.

  The head unit 21 has a plurality of nozzles Nz arranged in the CD direction, and is an ink ejection unit that ejects ink droplets from each nozzle Nz. The head unit 21 is provided for each color of ink (cyan ink, magenta ink, yellow ink, black ink). A plurality (four in this case) of head units 21 are arranged side by side along the MD direction. Each head unit 21 has a plurality (four in this case) of heads 22 arranged in a staggered pattern along the CD direction, and each head 22 has a plurality of nozzles Nz arranged in the CD direction. . Thereby, each head unit 21 can eject ink to the whole area | region of the width direction of the outer layer continuous sheet 9A. The head unit 21 may be capable of discharging a plurality of colors of ink. Further, the head unit 21 may have one head 22 or three or more heads. Further, the ink droplet ejection method by the head 22 may be a piezoelectric method using a piezoelectric element, a thermal method using a heater, or another method. Here, the ink ejected from the nozzle Nz is an aqueous pigment ink. However, the ink may be an oil-based ink or a dye ink.

The conveyance roller 23 is a rotation roller that conveys the outer-layer continuous sheet 9A. The conveyance roller 23 supports the outer layer continuous sheet 9 </ b> A in the Z direction, so that the interval between the nozzle Nz of the head unit 21 and the outer layer continuous sheet 9 </ b> A is maintained. The conveyance roller 23 may be rotated by a driving force of a motor, or may be rotated passively by contacting the outer layer continuous sheet 9A.
The transport roller 23 is disposed at a position not facing the nozzle Nz of the head unit 21. This is because the outer layer continuous sheet 9A, which is a printing medium, is a non-woven fabric, so that ink droplets may pass between the fibers of the non-woven fabric.
Moreover, the conveyance roller 23 is also arrange | positioned between the head units 21 in MD direction. If the conveyance roller 23 is not disposed between the head units 21 in the MD direction, the interval between the two conveyance rollers 23 sandwiching the printing area is widened, and the outer continuous sheet 9A is bent. On the other hand, in this embodiment, the conveyance roller 23 is arrange | positioned also between the head units 21 in MD direction, and the bending of the outer layer continuous sheet 9A can be suppressed.

  The print control unit 24 is a control unit that controls the operation of the inkjet printing apparatus 20. For example, the print control unit 24 controls the ejection timing and the ejection amount of the ink droplets ejected from each nozzle Nz of the head unit 21 by controlling the head unit 21.

By the way, in the joining device 60 (see FIG. 3), which will be described later, after the inner layer continuous sheet 8A (stretchable sheet) stretched in the MD direction and the low stretch outer layer continuous sheet 9A are pasted together, the stretched state is released. Then, as the stretchable inner layer sheet 8 contracts in the MD direction (width direction of the diaper 1; see FIG. 1B), the low stretchable outer layer sheet 9 forms a plurality of wrinkles in the MD direction. Will contract. In consideration of the shrinkage, the inkjet printing apparatus 20 prints the image G on the outer continuous sheet 9A.
FIG. 5 is an explanatory diagram of the image G before and after contraction. The upper diagram of FIG. 5 is an explanatory diagram of the final image G after contraction. The lower diagram in FIG. 5 is an image G printed on the outer-layer continuous sheet 9A, and is an explanatory diagram of the image G before contraction. For example, when the stretch magnification of the stretchable inner layer continuous sheet 8A is 1.5 times, an image G (see the lower diagram) obtained by stretching the image G to be printed (see the upper diagram) by 1.5 times in the MD direction. The image G generated and expanded in the MD direction is inkjet printed on the outer layer continuous sheet 9A. The image G (see the figure below) expanded in the MD direction may be generated by the print control unit 24, or may be generated by an external image processing device and transmitted to the print control unit 24.

  In the ink jet printing apparatus 20, printing is performed using the outer layer continuous sheet 9A having a small elongation rate as a printing medium, and thus it is easy to form a good image G. If inkjet printing is performed using the inner layer continuous sheet 8A (stretchable sheet) as a printing medium, the inner layer continuous sheet 8A has a dense structure. Therefore, when the inner layer continuous sheet 8A expands during transportation, the gap between the fibers on the surface. The density of (voids) spreads, and the deviation of the landing positions of ink droplets tends to increase. In contrast, the low-strength outer layer continuous sheet 9A has a smaller gap between fibers than the inner layer continuous sheet 8A, and the surface is easily maintained in a uniform state. The image G becomes good.

  Since there is a gap (gap) between the fibers on the surface of the outer layer continuous sheet 9A, which is a non-woven fabric, the ink that has landed from the printing surface passes through the gaps between the fibers on the surface and penetrates into the outer layer continuous sheet 9A. To do. That is, the ink adheres not only to the fibers on the surface of the outer layer continuous sheet 9A but also to the fibers inside the outer layer continuous sheet 9A. Further, since the ink is applied from the printing surface side, the closer to the printing surface, the more ink is attached to the fibers.

・ Drying device 30
When ink jet printing is performed on the outer layer continuous sheet 9A, which is a non-woven fabric, if the ink droplets are small, the ink droplets may pass between the fibers of the outer layer continuous sheet 9A, resulting in insufficient print density. For this reason, the inkjet printing apparatus 20 discharges relatively large ink droplets to the outer layer continuous sheet 9A. However, when ink jet printing is performed with large ink droplets, the amount of ink adhering to the outer continuous layer sheet 9A increases, so that drying tends to be insufficient. In addition, when an inkjet printing process is incorporated in the production line LM of the diaper 1, if the drying after inkjet printing is insufficient, the transport rollers of the production line LM may be stained with ink. Therefore, the production line LM of this embodiment includes a drying device 30. The drying device 30 includes a linear conveyance type drying device 40 and a drum type drying device 50.

..Linear conveyance type drying device 40
FIG. 6 is an explanatory diagram of the configuration of the linear conveyance type drying apparatus 40. The linear conveyance type drying apparatus 40 is an apparatus that is disposed on the downstream side of the inkjet printing apparatus 20 and that dries the outer layer continuous sheet 9A that has been inkjet printed in a linear conveyance path. The linear conveyance type drying apparatus 40 includes a drying chamber 41, a conveyance roller 42, and a plurality of outlets 43.

  The drying chamber 41 is a member that partitions a drying region around the conveyance path of the outer layer continuous sheet 9A. Here, the inside of the drying chamber 41 is kept at a high temperature, and the outer-layer continuous sheet 9 </ b> A is heated in the drying chamber 41.

  By the way, just putting the outer layer continuous sheet 9A, which is a nonwoven fabric, in the high temperature atmosphere in the drying chamber 41 makes it difficult to heat the inside of the outer layer continuous sheet 9A because the intertwined fibers function like a heat insulating material. In particular, when ink-jet printing is performed on the outer layer continuous sheet 9A that is a nonwoven fabric, the ink penetrates through the voids on the surface of the nonwoven fabric, so that the outer layer continuous sheet 9A that is a nonwoven fabric is placed in a high-temperature atmosphere. It is difficult to dry the ink adhering to the internal fibers only by putting it in the ink. Therefore, drying air is passed in the thickness direction of the outer layer continuous sheet 9A, which is a non-woven fabric, to dry the ink that has permeated inside.

  When drying air is passed in the thickness direction of the outer layer continuous sheet 9A, which is a non-woven fabric, a gap between intertwined fibers becomes a flow path. For this reason, when the space | gap between fibers is small, a pressure loss will become large and it will become difficult to flow the air for drying. Therefore, when the outer layer continuous sheet 9A is transported in the drying chamber 41, a predetermined tension that does not cause plastic deformation is applied to the outer layer continuous sheet 9A, and the thickness direction of the outer layer continuous sheet 9A in a tensioned state is applied. The drying air is passed through. Thereby, since the space | gap between fibers spreads, the air for drying can be passed in the state which reduced the pressure loss. Moreover, by this, the flow rate of the drying air passing through the outer continuous layer sheet 9A can be increased, and drying can be promoted. In addition, although the outer continuous sheet 9A is a low stretch sheet, it is permitted to apply a tension that does not cause plastic deformation (a degree that the low stretch sheet is not damaged). Even if the tension is applied to such an extent that the plastic deformation does not occur, the gap between the fibers becomes wider than when no tension is applied, and the pressure loss can be reduced.

  The conveyance roller 42 is a rotation roller that conveys the outer layer continuous sheet 9 </ b> A in the drying chamber 41. The conveyance roller 42 is disposed at a position facing the air outlet 43. Since the conveyance roller 42 supports the outer layer continuous sheet 9 </ b> A in the Z direction, the outer layer continuous sheet 9 </ b> A is suppressed from being bent by the dry air blown out from the air outlet 43. The transport roller 42 may be rotated by a driving force of a motor, or may be passively rotated by contacting the outer layer continuous sheet 9A.

  The blower outlet 43 is a part that blows out the drying air. By blowing drying air from the blower outlet 43 toward the outer layer continuous sheet 9A, the drying air is passed in the thickness direction of the outer layer continuous sheet 9A, which is a nonwoven fabric. The blower outlet 43 blows out the drying air from a slit-like opening elongated in the CD direction. Thereby, the blower outlet 43 can spray the air for drying to the whole area | region of the width direction of the outer layer continuous sheet 9A. The drying air is a gas for drying the ink forming the image G. The drying air is here dehumidified heated air, but it may be heated air or unheated dehumidified air.

  The blower outlet 43 is arrange | positioned so as to oppose the printing surface of the outer layer continuous sheet 9A, and blows off the drying air toward the printing surface. Since the amount of ink adhering to the fiber increases as it is closer to the printing surface, disposing the air outlet 43 on the printing surface side of the outer layer continuous sheet 9A makes it easier to dry the ink.

  The plurality of air outlets 43 are provided in a common pressurizing chamber 44 as shown in FIG. Thereby, uniform drying air can be blown out from the plurality of outlets 43.

  By the way, in order to allow drying air to pass in the thickness direction of the outer continuous layer sheet 9A, if the upper surface side of the outer continuous layer sheet 9A is in a pressurized atmosphere and the lower surface side is in a reduced pressure atmosphere, pressure is applied to the entire surface of the outer continuous layer sheet 9A. The outer layer continuous sheet 9A is bent. On the other hand, in this embodiment, since the drying air is blown out from the air outlet 43 toward the outer layer continuous sheet 9A, only a pressure is applied to a local area (an area facing the air outlet 43). The bending of the sheet 9A can be suppressed. In addition, since the conveyance roller 42 exists in the position facing the blower outlet 43, even if it receives a pressure in the area | region facing the blower outlet 43, the outer-layer continuous sheet 9A is hard to bend.

  FIG. 7 is a cross-sectional view of the air outlet 43. The air outlet 43 has a slit shape in which an opening having a width W in the MD direction extends in the CD direction. The blower outlet 43 has a flow path formed by a pair of plate-like members 431 arranged to face each other in the MD direction, and a throttle part 432 and a rectifying part 433 are formed in the flow path. The restrictor 432 is a part that restricts the flow path of the drying air. The interval in the MD direction of the flow path in the throttle portion 432 is wider toward the pressurizing chamber 44 side (flow path upstream side) and narrower toward the opening 434 side (flow path downstream side). The rectifying unit 433 is a part that rectifies the drying air on the downstream side of the flow path of the throttle unit 432, and has a shape in which the width W in the MD direction is constant. By providing the rectifying unit 433, it is possible to uniformly blow out the drying air from the slit-like opening 434 (blow-out opening 43) of the rectifying unit 433.

  The drying chamber 41 is provided with a suction port (not shown) for sucking the drying air that has passed through the outer layer continuous sheet 9A. The drying air sucked from the suction port may be discharged to the outside, or may be circulated and blown again from the outlet 43. When the drying air is circulated, it is desirable to provide various filters (dehumidification filter, particle filter, chemical filter, etc.) in the circulation path. When the suction port sucks the drying air that has passed through the outer continuous layer sheet 9A, the drying air easily passes through the outer continuous layer sheet 9A.

..Drum-type drying device 50
FIG. 8 is a configuration diagram of the drum-type drying device 50. The drum-type drying device 50 includes a first drum drying device 50A and a second drum drying device 50B. The first drum drying device 50A includes a first drum drying chamber 51A, a first drum 52A, a plurality of air outlets 53, and a suction port 56. The second drum drying device 50B includes a second drum drying chamber 51B, a second drum 52B, a plurality of air outlets 53, and a suction port 56. The first drum drying device 50A is disposed on the upstream side in the MD direction with respect to the second drum drying device 50B. Since the configurations of the first drum drying device 50A and the second drum drying device 50B are substantially the same, only the first drum drying device 50A will be described here, and the description of the second drum drying device 50B will be omitted.

  The first drum drying chamber 51A is a member that divides a drying region around the first drum 52A, which is a conveyance path of the outer layer continuous sheet 9A. It should be noted that the first drum drying chamber 51A and the second drum drying chamber 51B may be shared without being divided. The first drum 52A is a rotating drum that conveys the outer-layer continuous sheet 9A by rotating while holding the outer-layer continuous sheet 9A on the outer peripheral surface. Since the outer continuous layer sheet 9A is held on the outer peripheral surface of the first drum 52A, compared to the case where the outer continuous layer sheet 9A is supported by the conveying roller as in the linear drying device 40 described above, the drying air is supplied in the thickness direction. The outer layer continuous sheet 9A is difficult to bend when passing through. The first drum 52A is rotated by a drive motor (not shown), whereby the outer continuous sheet 9A is conveyed.

FIG. 9A is an explanatory diagram of a cross-sectional structure of the outer peripheral surface of the first drum 52A. FIG. 9B is an explanatory diagram of the metal plate 521. FIG. 9C is an explanatory diagram of the mesh member 522. As shown in FIG. 9A, the outer peripheral surface of the first drum 52 </ b> A is configured by overlapping a metal plate 521 and a mesh member 522. The metal plate 521 is a so-called punching metal in which a number of punched holes to be vent holes are formed (see FIG. 9B). In the metal plate 521, for example, round punched holes having a diameter D of 5 mm are arranged in a staggered pattern of 60 degrees with a pitch P of 8 mm. The mesh member 522 is a mesh member formed by weaving a wire material into a mesh, and the mesh becomes a vent (see FIG. 9C). The net-like member 522 may be, for example, a metal net that is plain-woven with a metal wire, or a plastic net that is plain-woven with plastic wires. The mesh (interval between the wire rods) of the mesh member 522 is set smaller than the diameter of the punched hole of the metal plate 521.
If the outer peripheral surface of the first drum 52A is constituted only by the metal plate 521, there is a possibility that traces of vent holes (in this case, punched holes of the metal plate 521) remain in the outer layer continuous sheet 9A. Further, if the outer peripheral surface of the first drum 52A is configured only by the mesh member 522, the outer peripheral surface of the first drum 52A may be deformed. On the other hand, as shown in FIG. 9A, when the outer peripheral surface of the first drum 52A is configured by superimposing the metal plate 521 and the mesh member 522, the mesh of the mesh member 522 is small, so that the outer layer continuous sheet 9A is ventilated. The trace of the hole is difficult to remain, and the mesh member 522 is supported by the metal plate 521, so that deformation of the mesh member 522 can be suppressed.

  The blower outlet 53 is a part which blows off the drying air (see FIG. 8). The air outlet 53 of the drum type drying apparatus 50 has the same shape as the air outlet 43 of the linear conveyance type drying apparatus 40 (see FIG. 7), and blows drying air from a slit-like opening elongated in the CD direction. The plurality of air outlets 53 are provided in a common pressurization chamber 54 as shown in FIG.

  The width W (see FIG. 7) of the slit-shaped air outlet 53 in the MD direction is a vent hole formed in the outer peripheral surface of the first drum 52A or the second drum 52B (the diameter D of the punching hole in FIG. 9B or FIG. 9C). It is desirable that the mesh size is set to be narrower than the width in the MD direction. Thereby, when the blower outlet 53 opposes the ventilation hole, the drying air easily passes in the thickness direction of the outer layer continuous sheet 9A.

  The plurality of outlets 53 of the drum-type drying device 50 are disposed so as to face the outer peripheral surface of the first drum 52A (or the second drum 52B). By supplying the outer layer continuous sheet 9 </ b> A to the first drum 52 </ b> A so that the print surface faces the outer surface of the first drum 52 </ b> A, the print surface faces the air outlet 53, and the air outlet 53 is continuous with the outer layer. Drying air is blown out toward the printing surface of the sheet 9A. Since the amount of ink adhering to the fibers increases as the printing surface is closer, the ink is easily dried by supplying the outer layer continuous sheet 9A to the first drum 52A so that the printing surface of the outer layer continuous sheet 9A faces outward. . The conveyance path for conveying the outer continuous layer sheet 9A from the linear conveyance type drying device 40 to the first drum 52A of the drum type drying device 50 is such that the outer layer continuous sheet 9A is directed so that the printing surface of the outer layer continuous sheet 9A faces outward. This is a supply unit that supplies the drum 52A.

  In addition, when the outer continuous layer sheet 9A is supplied to the first drum 52A, a predetermined tension that does not cause plastic deformation is applied to the outer continuous layer sheet 9A, and the first drum 52A (or the first drum 52A (or the first drum 52A) is applied with the tension applied. The outer continuous sheet 9A is held on the outer peripheral surface of the two drums 52B). Thereby, since the space | gap between fibers spreads, the air for drying can be passed in the state which reduced the pressure loss. Moreover, by this, the flow rate of the drying air passing through the outer continuous layer sheet 9A can be increased, and drying can be promoted.

  The suction port 56 is a part that sucks the drying air that has passed through the outer layer continuous sheet 9A from the inside of the first drum 52A (or the second drum 52B). When the suction port 56 sucks the drying air, the inside of the first drum 52A becomes a reduced pressure atmosphere. Thereby, since the outer layer continuous sheet 9A is adsorbed to the outer peripheral surface, the outer layer continuous sheet 9A held by the first drum 52A is not easily displaced during conveyance. Further, when the inside of the first drum 52A is in a reduced pressure atmosphere, a pressure difference can be formed on the front and back of the outer layer continuous sheet 9A, and drying air can be passed in the thickness direction of the outer layer continuous sheet 9A. In particular, in the region facing the air outlet 53, the drying air can be easily passed in the thickness direction of the outer layer continuous sheet 9A. Even in a region that does not face the air outlet 53, the inside of the first drum 52A is in a reduced pressure atmosphere, so the drying air passes in the thickness direction of the outer continuous sheet 9A although the flow rate is small. For this reason, the drum-type drying device 50 that adsorbs and conveys the outer-layer continuous sheet 9 </ b> A can dry the outer-layer continuous sheet 9 </ b> A more efficiently than the linear conveyance-type drying device 40.

  The drum-type drying device 50 includes two drums (a first drum 52A and a second drum 52B), and the outer layer continuous sheet 9A is dried while being conveyed in each drum. If an attempt is made to secure the same conveyance distance (drying section) with one drum, the drum will be enlarged. However, by performing drum drying using two drums, the drum is secured while ensuring the conveyance distance (drying section). Can be reduced in size.

  In order to ensure a long drying section in the first drum 52A (or the second drum 52B), the outer continuous layer sheet 9A is conveyed in a state in which the outer continuous layer sheet 9A is wound around the outer circumferential surface of the first drum 52A or more. It is desirable to do. As a result, the MD direction of the outer-layer continuous sheet 9A when supplied to the first drum 52A and the MD direction of the outer-layer continuous sheet 9A when separated from the first drum 52A are crossing each other.

  On the other hand, since the MD direction at the time of supply of the first drum 52A and the MD direction at the time of separation intersect, the outer layer continuous sheet 9A is conveyed to the second drum 52B so that the outer layer continuous sheet 9A does not interfere at the entrance / exit of the first drum 52A. In order to do this, it is necessary to change the conveying direction of the outer continuous layer sheet 9A between the first drum 52A and the second drum 52B. At this time, the printing surface of the outer continuous layer sheet 9 </ b> A comes into contact with the transport roller 57. However, the outer layer continuous sheet 9A is semi-dried by the drying process by the first drum 52A, and the ink of the outer layer continuous sheet 9A is not dried up to the inside but is solidified (semi-dried state). ing. For this reason, even when the outer layer continuous sheet 9A is transported from the first drum 52A to the second drum 52B, the transport roller 57 is brought into contact with the printing surface of the outer layer continuous sheet 9A to change the MD direction of the outer layer continuous sheet 9A. It is possible to suppress the conveyance roller 57 from being contaminated with ink. In particular, since the drying process by the linear conveyance type drying device 40 is also performed before the first drum 52A, the ink contamination of the conveyance roller 57 can be further suppressed.

  When the outer layer continuous sheet 9A is transported from the first drum 52A to the second drum 52B, the transport roller 57 that contacts the printing surface of the outer layer continuous sheet 9A is here the first drum drying chamber 51A (or the second drum drying chamber 51B). However, it may be arranged outside the first drum drying chamber 51A (see FIG. 11 of the second embodiment to be described later).

  Further, it is desirable that the transport roller 57 is rotated at a rotational speed corresponding to the transport speed of the outer continuous sheet 9A by a driving force of a motor (not shown). Thereby, it can suppress that the surface of the conveyance roller 57 and a printing surface mutually rub, and the ink contamination of the conveyance roller 57 can further be suppressed. However, if the ink surface is sufficiently solidified by the drying process by the first drum 52A, the transport roller 57 may rotate passively by contacting the outer layer continuous sheet 9A.

  After the outer layer continuous sheet 9A is dried while being conveyed in the second drum drying device 50B, the outer layer continuous sheet 9A is separated from the second drum 52B and carried out of the second drum drying chamber 51B. Since the inside of the second drum drying chamber 51B is heated to high temperature by heated air (drying air), the outer continuous sheet 9A is cooled when carried out of the second drum drying chamber 51B. By cooling the outer layer continuous sheet 9A, the ink adhering to the outer layer continuous sheet 9A is also cooled, and the fixing property and the abrasion resistance of the ink are improved.

  As shown in FIG. 3, the outer continuous layer sheet 9 </ b> A carried out from the drum-type drying device 50 (second drum drying chamber 51 </ b> B) is conveyed to the joining device 60 outside the print drying device 11. The conveyance path from the drum-type drying device 50 to the joining device 60 (or the outlet of the print drying device 11) is a cooling section for the outer-layer continuous sheet 9A after heat drying. In the first embodiment, the outer-layer continuous sheet 9A carried out from the drum-type drying device 50 is conveyed in the MD direction different from the MD direction in the drum-type drying device 50 in a path along the outer wall surface of the drum-type drying device 50. Is done. Thereby, since the conveyance path used as a cooling section can be arranged in a space-saving manner, the print drying apparatus 11 can be reduced in size while extending the cooling section of the outer layer continuous sheet 9A after drying by heating.

-Other process of manufacturing line LM As shown in FIG. 3, the manufacturing line LM is provided with the joining apparatus 60 other than the printing drying apparatus 11. As shown in FIG. The joining apparatus 60 is an apparatus for joining the inner layer continuous sheet 8A and the outer layer continuous sheet 9A in a state where they are overlapped in the thickness direction. Here, the joining device 60 is an ultrasonic welding device having an anvil roller 61 and an ultrasonic horn 62.

  The anvil roller 61 of the joining device 60 has a stretchable inner layer continuous sheet 8A in a stretched state stretched in the MD direction at a predetermined stretch ratio (for example, 2.5 times the natural length), and a stretched state in the MD direction ( A low-stretch outer-layer continuous sheet 9A in a state in which a tension that does not cause plastic deformation is applied is supplied. The inner layer continuous sheet 8A and the outer layer continuous sheet 9A are wound around the outer peripheral surface of the anvil roller 61 in a state of being overlapped in the thickness direction, and the anvil roller 61 rotates and the inner layer continuous sheet 8A and the outer layer continuous sheet 9A are ultrasonic. It is welded when passing through the horn 62, and the exterior continuous sheet 7A is generated.

  As shown in FIG. 3, the inner layer continuous sheet 8A is joined to the surface opposite to the printing surface of the outer layer continuous sheet 9A. Thereby, the welding failure by an ink can be suppressed and the joining strength of inner layer continuous sheet 8A and outer layer continuous sheet 9A can be kept strong. In addition, since the printing surface of the outer layer continuous sheet 9A is arranged on the opposite side of the inner layer continuous sheet 8A, the printing surface of the outer layer continuous sheet 9A is arranged on the non-skin side of the exterior sheet 7 of the diaper 1 (FIG. 2). Reference), the image G of the exterior sheet 7 of the diaper 1 can be viewed in a colorful manner.

  Further, as shown in FIG. 3, when the inner layer continuous sheet 8A and the outer layer continuous sheet 9A are superimposed on the outer peripheral surface of the anvil roller 61, the outer layer continuous sheet 9A is set to the inner side (anvil roller 61 side), and the inner layer continuous sheet 8A. Is on the outside (on the ultrasonic horn 62 side). Thereby, since the ultrasonic horn 62 does not touch the printing surface of the outer layer continuous sheet 9A, ink contamination of the ultrasonic horn 62 can be suppressed.

  FIG. 10 is a process explanatory diagram from the generation of the exterior continuous sheet 7A to the completion of the diaper 1. The production line LM forms an opening that becomes a leg opening HL (see FIG. 1A) in the exterior continuous sheet 7A. This opening is formed by being punched from the exterior continuous sheet 7A by an annular cutter blade (not shown). Next, the exterior continuous sheet 7A conveyed in the stretched state is contracted in the MD direction, and a ridge is formed on the outer surface of the exterior continuous sheet 7A. Next, the absorptive main body 3 is attached between the leg openings HL of the exterior continuous sheet 7A, and the exterior continuous sheet 7A is folded in two. The end seal part is formed by welding in the CD direction from the leg-hole opening HL of the exterior continuous sheet 7A folded in half, and the exterior continuous sheet 7A is divided by the end seal part, and the separated part becomes the diaper 1.

<Summary of the first embodiment>
The drying device 30 of the first embodiment is a drying device that dries the outer-layer continuous sheet 9A (corresponding to a sheet) that constitutes the diaper 1 (corresponding to an absorbent article) and has an image G printed by inkjet printing. The drying device 30 includes a first drum drying chamber 51A (corresponding to a drying chamber) and a first drum (corresponding to a drum) of the drum-type drying device 50. The first drum is provided inside the first drum drying chamber 51A, and conveys the outer continuous layer sheet 9A by rotating while holding the outer continuous layer sheet 9A on the outer peripheral surface. The drying device 30 has a conveyance path for conveying the outer layer continuous sheet 9A from the linear conveyance type drying apparatus 40 to the first drum 52A of the drum type drying apparatus 50, and this conveyance path is the conveyance path of the outer layer continuous sheet 9A. The supply unit supplies the outer layer continuous sheet 9 </ b> A to the first drum 52 </ b> A so that the printing surface faces outward. When the image G is printed on the outer layer continuous sheet 9A by ink-jet printing, the closer to the printing surface, the more ink is attached to the fibers. Therefore, the outer layer continuous sheet 9A is the first so that the printing surface of the outer layer continuous sheet 9A faces outward. The ink is easily dried by being supplied to the drum 52A.

=== Second Embodiment ===
FIG. 11 is an explanatory diagram of the print drying apparatus 11 according to the second embodiment. The print drying apparatus 11 of the second embodiment also includes an inkjet printing apparatus 20 and a drying apparatus 30. The inkjet printing apparatus 20 has substantially the same configuration and function as the inkjet printing apparatus 20 of the first embodiment. The drying device 30 includes a linear conveyance type drying device 40 and a drum type drying device 50.

  The linear conveyance type drying apparatus 40 according to the second embodiment includes a first drying apparatus 40A and a second drying apparatus 40B. The first drying device 40A is arranged on the upstream side in the MD direction with respect to the second drying device 40B. Since the shape and configuration of the first drying device 40A and the second drying device 40B are substantially the same, the shape of the first drying device 40A will be described here, and the description of the second drying device 40B will be omitted.

  The first drying device 40A includes a first drying chamber 41A, a belt conveyance device 46, and a plurality of air outlets 43. The first drying chamber 41A is a member that partitions a drying region around the conveyance path of the outer layer continuous sheet 9A. The blower outlet 43 is a part that blows out the drying air. The plurality of air outlets 43 are provided in a common pressurizing chamber 44 as shown in FIG.

  The belt conveyance device 46 is a device that conveys the outer continuous layer sheet 9A in a belt in the first drying chamber 41A (and the second drying chamber 41B). FIG. 12 is an explanatory diagram of the belt conveyance device 46. The belt 462 is configured by a mesh member 462 having substantially the same configuration as the mesh member 522 shown in FIG. 9C so that the outer layer continuous sheet 9A can be adsorbed. A metal plate 461 having substantially the same configuration as the punching metal (metal plate 521) shown in FIG. 9B is disposed on the opposite side of the suction surface of the belt 462, and the inside of the region partitioned by the metal plate 461 (see FIG. The upper region in the inside is a decompression chamber 47 in a decompressed atmosphere. As a result, the outer layer continuous sheet 9A is conveyed while being adsorbed on the belt circumferential surface (that is, the belt conveying device 46 has a configuration in which the mesh member 462 adsorbing the outer layer continuous sheet 9A moves relative to the metal plate 461. Become).

  When the outer layer continuous sheet 9A is supplied to the belt conveyance device 46, a predetermined tension that does not cause plastic deformation is applied to the outer layer continuous sheet 9A, and the outer layer continuous sheet 9A is applied to the belt circumferential surface in a state where the tension is applied. It is held. Thereby, since the space | gap between fibers spreads, the air for drying can be passed in the state which reduced the pressure loss. Moreover, by this, the flow rate of the drying air passing through the outer continuous layer sheet 9A can be increased, and drying can be promoted.

  The belt 462 of the belt conveying device 46 is provided so as to pass through both the first drying device 40A and the second drying device 40B. However, the belt conveying device 46 may be provided in each of the first drying device 40A and the second drying device 40B. In addition, a portion of the belt 462 of the belt conveyance device 46 that moves from the upstream side in the MD direction to the downstream side (a portion that conveys the outer layer continuous sheet 9A) is disposed inside the first drying chamber 41A and the second drying chamber 41B. However, the portion that moves from the downstream side to the upstream side is disposed outside the first drying chamber 41A and the second drying chamber 41B. Thereby, since the entrances and exits of the belt 462 of the first drying chamber 41A (and the second drying chamber 41B) can be reduced, the temperature in the drying chamber of the first drying chamber 41A (and the second drying chamber 41B) can be easily maintained.

  The belt conveyance device 46 can convey the outer layer continuous sheet 9 </ b> A in a state where the outer layer continuous sheet 9 </ b> A is on the lower side in the gravity direction with respect to the belt 462 in order to adsorb the outer layer continuous sheet 9 </ b> A to the belt 462. Thereby, the arrangement | positioning (layout) of a conveyance path | route as mentioned later is attained, and the printing drying apparatus 11 can be reduced in size compared with the case where all the conveyance paths are arranged on a straight line.

  The drum-type drying device 50 according to the second embodiment has substantially the same configuration and function as the drum-type drying device 50 according to the first embodiment. However, in the drum-type drying apparatus 50 of the second embodiment, the conveyance roller 57 (the conveyance roller 57 that contacts the printing surface of the outer layer continuous sheet 9A when the outer layer continuous sheet 9A is conveyed from the first drum 52A to the second drum 52B). ) Is disposed outside the first drum drying chamber 51A and the second drum drying chamber 51B. Thereby, the first drum drying chamber 51A and the second drum drying chamber 51B are downsized. Further, if the surface of the transport roller 57 becomes high temperature, the ink (resin) may be melted or peeled off when the transport roller 57 comes into contact with the printing surface, whereas in the second embodiment, the transport roller 57 Is disposed outside the first drum drying chamber 51 </ b> A and the second drum drying chamber 51 </ b> B, it is possible to prevent the surface of the transport roller 57 that contacts the printing surface from becoming high temperature.

-Conveyance route The conveyance route of the printing drying apparatus 11 of the second embodiment is the conveyance route P11 before printing, the conveyance route P12 during printing, the conveyance route P13 before drying, the conveyance route P14 during linear drying, and the conveyance before drum drying. A path P15, a drum drying transport path P16, and a post-drying transport path P17 are provided.

  The pre-printing conveyance path P <b> 11 is a conveyance path for conveying the outer-layer continuous sheet 9 </ b> A to the printing area of the inkjet printing apparatus 20. The pre-printing conveyance path P <b> 11 (such as a conveyance roller constituting the pre-printing conveyance path P <b> 11) serves as a supply unit that supplies the outer layer continuous sheet 9 </ b> A to the inkjet printing apparatus 20.

  The printing conveyance path P <b> 12 is a conveyance path for conveying the outer layer continuous sheet 9 </ b> A in the printing region of the inkjet printing apparatus 20. For example, the conveyance path formed by the conveyance rollers in FIG. 4A is the conveyance path P12 during printing. In the printing transport path P12, the image G is inkjet printed on the outer continuous sheet 9A.

  In the following description, the transport direction of the outer continuous sheet 9A in the transport path P12 during printing may be referred to as “printing direction”. The plurality of head units 21 of the inkjet printing apparatus 20 are arranged side by side in the printing direction (corresponding to a predetermined direction). The direction from the left to the right in FIG. 11 (the direction of the arrow indicating the transport direction in the transport path P12 during printing) is the print direction.

  The pre-drying conveyance path P <b> 13 is a conveyance path from the inkjet printing apparatus 20 to the linear conveyance type drying apparatus 40. An image G that has just been ink-jet printed is formed on the outer layer continuous sheet 9A in the transport path P13 before drying. For this reason, in the pre-drying conveyance path P13, the conveyance roller cannot be disposed on the printing surface side of the outer layer continuous sheet 9A, and the conveyance roller 71 is in contact with the surface opposite to the printing surface of the outer layer continuous sheet 9A. The outer continuous sheet 9A is conveyed.

  The linear drying conveyance path P14 is a linear conveyance path in the linear conveyance type drying apparatus 40. Here, the linear drying conveyance path P <b> 14 is a conveyance path configured by the belt conveyance device 46. As described above, the drying air is passed through the outer layer continuous sheet 9A in the linear drying path.

  The conveyance path P15 before drum drying is a conveyance path for conveying the outer-layer continuous sheet 9A from the linear conveyance type drying apparatus 40 to the drum type drying apparatus 50. The conveyance path P15 before drum drying serves as a supply unit that supplies the outer layer continuous sheet 9A to the drum-type drying device 50. In addition, as described above, the supply unit (conveyance path P15 before drum drying) supplies the outer layer continuous sheet 9A to the first drum 52A so that the printing surface of the outer layer continuous sheet 9A faces outward. In addition, the supply unit (conveying path P15 before drum drying) applies the outer layer continuous sheet 9A to the first drum 52A in a tensioned state while applying a predetermined tension that does not cause plastic deformation to the outer layer continuous sheet 9A. Supply.

  The drum drying conveyance path P <b> 16 is a conveyance path in the drum-type drying apparatus 50. The drum drying transport path P16 includes a curved transport path formed by the outer peripheral surfaces of the first drum 52A and the second drum 52B, and a relay transport path between the first drum 52A and the second drum 52B. included. As described above, the drying air is passed through the outer continuous sheet 9A in the curved conveyance path. Further, in the relay conveyance path, the outer continuous layer sheet 9A is semi-dried, and the ink of the outer continuous layer sheet 9A is not dried to the inside but is solidified (semi-dried state). For this reason, the relay conveyance path includes a conveyance roller that contacts the printing surface of the outer continuous layer sheet 9A. The conveyance roller in the relay conveyance path serves as a supply unit that supplies the outer layer continuous sheet 9A to the second drum 52B so that the printing surface of the outer layer continuous sheet 9A faces outward.

  The post-drum transport path P <b> 17 is a transport path for transporting the continuous outer layer sheet 9 </ b> A from the drum-type drying device 50 to the outside of the print drying device 11. In the conveyance path P17 after drum drying, the outer-layer continuous sheet 9A heated by the drum-type drying device 50 is cooled. By cooling the outer continuous layer sheet 9A after heat drying, the ink fixing property and the abrasion resistance are improved.

  In the present embodiment, as shown in FIG. 11, the MD direction of the outer continuous layer sheet 9 </ b> A is reversed by the transport roller 71 in contact with the surface opposite to the printing surface of the outer continuous layer sheet 9 </ b> A in the transport path P <b> 13 before drying. ing. As a result, the MD direction of the outer layer continuous sheet 9A is reversed between the conveyance path P12 during printing and the conveyance path P14 during linear drying. Therefore, as shown in FIG. 11, the conveyance path P12 during printing and the conveyance path P14 during linear drying. Are arranged so as to partially overlap in the printing direction. Thereby, compared with the case where the conveyance path P12 for printing and the conveyance path P14 for linear drying are arranged in series in the printing direction as in the first embodiment, the size in the entire printing direction of the printing drying apparatus 11 is reduced. The print drying process can be realized in a space-saving area.

  As shown in FIG. 11, a plurality of head units 21 of the ink jet printing apparatus 20 are arranged in the conveyance path P12 during printing, and a linear conveyance type drying apparatus 40 is arranged in the conveyance path P14 during linear drying. Therefore, by reversing the MD direction of the outer continuous sheet 9A between the transport path P12 during printing and the transport path P14 during linear drying, as shown in FIG. 11, the plurality of head units 21 of the inkjet printing apparatus 20 The arranged region and the linear conveyance type drying device 40 are arranged so as to partially overlap in the printing direction (that is, the inkjet printing device 20 and the linear conveyance type drying device 40 are arranged vertically). Thereby, the dimension of the whole printing direction of the printing drying apparatus 11 can be reduced compared with the case where the inkjet printing apparatus 20 and the linear conveyance type drying apparatus 40 are arranged in series in the printing direction as in the first embodiment. .

  As shown in FIG. 11, in order to further dry the outer-layer continuous sheet 9A that has passed through the first drying device 40A of the linear conveyance type drying device 40, the second drying device 40B (corresponding to another drying device) performs the first drying. The device 40A is provided on the left side (the side opposite to the printing direction side) in the drawing. In this way, the second drying device 40B can be provided on the left side of the first drying device 40A because the MD direction of the outer-layer continuous sheet 9A is reversed between the transport route P12 during printing and the transport route P14 during linear drying. This is because the conveying path P14 during linear drying can be lengthened. As shown in FIG. 11, the second drying device 40B of the linear conveyance type drying device 40 and the first drum drying device 50A of the drum type drying device 50 are arranged so as to partially overlap in the printing direction. Yes. Thereby, since the 2nd drying apparatus 40B and the 1st drum drying apparatus 50A can be arrange | positioned up and down, the dimension of the whole printing direction of the printing drying apparatus 11 can be reduced in size.

  As shown in FIG. 11, in order to further dry the outer layer continuous sheet 9A that has passed through the first drum drying device 50A of the drum type drying device 50, a second drum drying device 50B (corresponding to another drum type drying device) is provided. It has been. Then, as shown in FIG. 11, the second drying device 40B (corresponding to another drying device) and the second drum drying device 50B (corresponding to another drum-type drying device) partially overlap in the printing direction. Is arranged. Thereby, since the 2nd drying apparatus 40B and the 2nd drum drying apparatus 50B can be arrange | positioned up and down, the dimension of the whole printing direction of the printing drying apparatus 11 can be reduced in size.

  As shown in FIG. 11, the post-drying conveyance path P17 is a path along the second drum drying device 50B, the first drum drying device 50A, the second drying device 40B, and the first drying device 40A. Therefore, the outer layer continuous sheet 9A dried by the second drum drying device 50B has a route along the second drum drying device 50B, the first drum drying device 50A, the second drying device 40B, and the first drying device 40A. Then, it is conveyed outside the printing drying apparatus 11. By arranging the post-drum transport path P17 in this way, the cooling section of the outer continuous layer sheet 9A after heat drying becomes longer, and the ink fixing property and abrasion resistance are improved.

  In addition, a part of the conveyance path P17 after drum drying is a path along the outer wall surface of the drum-type drying device 50, and the outer layer continuous sheet 9A carried out from the drum-type drying device 50 is the drum-type drying device 50. Is conveyed in the MD direction different from the MD direction in the drum-type drying device 50 in the path along the outer wall surface. Moreover, in 2nd Embodiment, another part of conveyance path | route P17 after drum drying is a path | route along the outer wall surface of the linear conveyance type drying apparatus 40, and the outer-layer continuous sheet 9A is a linear conveyance type drying apparatus. MD direction (direction from left to right in the figure) different from the MD direction (direction from right to left in the figure) in the linear conveyance type drying apparatus 40 on the outside of 40 along the linear conveyance type drying apparatus 40 To be transported. Thereby, since the conveyance path | route P17 after drum drying used as a cooling area can be arrange | positioned in space-saving, the printing drying apparatus 11 can be reduced in size, lengthening the cooling area of the outer layer continuous sheet 9A after heat drying.

<Summary of Second Embodiment>
The drying device 30 of the second embodiment includes a first drum drying chamber 51A (corresponding to a drying chamber) of the drum-type drying device 50, a first drum (corresponding to a drum), and a conveyance path P15 before drum drying. The drum pre-drying conveyance path P15 serves as a supply unit that supplies the outer layer continuous sheet 9A to the first drum 52A so that the printing surface of the outer layer continuous sheet 9A faces outward. When the image G is printed on the outer layer continuous sheet 9A by ink-jet printing, the closer to the printing surface, the more ink is attached to the fibers. Therefore, the outer layer continuous sheet 9A is the first so that the printing surface of the outer layer continuous sheet 9A faces outward. The ink is easily dried by being supplied to the drum 52A.

=== Other Embodiments ===
As mentioned above, although embodiment of this invention was described, said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. Further, the present invention can be changed or improved without departing from the gist thereof, and needless to say, the present invention includes equivalents thereof. For example, the following modifications are possible.

  The ink jet printing apparatus is a so-called line printer type in which a head unit is fixed. However, a serial type ink jet printing apparatus in which a head having a plurality of nozzles arranged in the MD direction reciprocates in the CD direction may be used.

  In the above-described embodiment, the low-extension outer continuous sheet 9A is a printing medium, but the printing medium is not limited to this. Inkjet printing may be performed on other nonwoven fabrics such as the inner-layer continuous sheet 8A and the exterior continuous sheet 7A, and inkjet printing may be performed on a printing medium other than the nonwoven fabric (for example, woven fabric). Moreover, although the sheet | seat (outer layer continuous sheet 9A) which comprises the underpants type diaper 1 was a to-be-printed medium, it is inkjet with respect to the sheet | seat which comprises other absorbent articles (for example, sanitary napkins, an incontinence pad, etc.). Printing may be performed.

In the above embodiment, the drying air is passed in the thickness direction of the outer continuous layer sheet 9A from the printing surface side. However, the drying air may be passed from the opposite surface. However, the closer to the printing surface, the greater the amount of ink attached to the fibers. Therefore, it is advantageous for drying to pass the drying air from the printing surface side. Further, it is not necessary to allow the drying air to pass in the thickness direction of the outer continuous layer sheet 9A. However, since the entangled fibers of the outer layer continuous sheet 9A function like a heat insulating material, it is difficult to dry the outer layer continuous sheet 9A to the inside only by placing it in the high temperature atmosphere in the first drum drying chamber 51A. It is advantageous to pass the drying air in the thickness direction of 9A.
Further, in the above embodiment, when the outer layer continuous sheet 9A is dried, a predetermined tension is applied to the outer layer continuous sheet 9A. However, the outer layer continuous sheet 9A may not be applied. However, since the gap between the fibers of the outer continuous sheet 9A is widened by applying the tension, the drying air can be passed with the pressure loss reduced, so that a predetermined tension is applied to the outer continuous sheet 9A. It is more advantageous to do so.

1 diaper (absorbent article), 3 absorbent body,
7 exterior sheet, 7A exterior continuous sheet,
8 inner layer sheet, 8A inner layer continuous sheet,
9 outer layer sheet, 9A outer layer continuous sheet,
G image, J joint,
HB waist opening, HL leg opening,
LM production line,
11 Print dryer, 12 Main controller 20 Inkjet printer,
21 head units, 22 heads, Nz nozzles,
23 transport roller, 24 print control unit,
30 dryers, 40 linear transport dryers,
40A first drying device,
40B second drying device,
41 drying chamber, 41A first drying chamber, 41B second drying chamber,
42 transport rollers, 43 air outlets,
431 Plate-like member, 432 throttle part,
433 rectification unit, 434 opening,
44 pressurized chambers, 46 belt conveyors,
461 metal plate (punching metal), 462 belt (net-like member),
47 vacuum chamber, 50 drum-type dryer,
50A first drum drying device,
50B second drum drying device,
51A first drum drying chamber (drying chamber), 51B second drum drying chamber,
52A first drum (drum), 52B second drum,
521 metal plate, 522 mesh member,
53 outlet, 54 pressurized chamber,
56 suction port, 57 transport roller,
60 joining device, 61 anvil roller,
62 ultrasonic horn, 71 transport roller,
P11 transport path before printing, P12 transport path during printing,
P13 Pre-drying conveyance path, P14 Linear drying conveyance path,
P15 Drum drying transport path (sheet supply unit), P16 Drum drying transport path,
P17 Drum transport path after drying

Claims (8)

A drying apparatus for a sheet comprising an absorbent article and having an image printed by ink jet printing,
A drying chamber;
A drum that is provided inside the drying chamber and conveys the sheet by rotating while holding the sheet on an outer peripheral surface;
A sheet supply unit that supplies the sheet to the outer peripheral surface of the drum so that a printing surface of the sheet faces outside,
Provide a blower outlet for blowing out the drying air at a position facing the outer peripheral surface,
A vent hole is formed in the outer peripheral surface of the drum,
Passing the drying air in the thickness direction of the sheet through the vent hole ,
Another drum for further drying the sheet that has passed through the drum is provided;
In the transport path between the drum and the other drum, a roller is provided to change the transport direction of the sheet in contact with the semi-dried printing surface of the sheet,
The drying apparatus, wherein the other drum further dries the sheet while holding and transporting the sheet so that a printing surface of the sheet faces outward . The drying apparatus according to claim 1,
The sheet supply unit supplies the sheet to the outer peripheral surface of the drum in a state where a predetermined tension is applied,
The drying apparatus, wherein the drying air is passed in the thickness direction of the sheet to which the tension is applied. The drying apparatus according to claim 1 or 2,
The width of the blower outlet in the sheet conveying direction is narrower than the width of the vent hole in the sheet conveying direction. The drying apparatus according to any one of claims 1 to 3,
The drying apparatus, wherein the sheet is wound around the outer peripheral surface equal to or more than a half circumference of the drum. A drying apparatus according to any one of claims 1 to 4 ,
The said roller is arrange | positioned on the outer side of the said drying chamber, The drying apparatus characterized by the above-mentioned. A drying apparatus according to any one of claims 1 to 5 ,
The drying device according to claim 1, wherein the roller rotates at a rotation speed corresponding to a conveyance speed of the sheet. A drying device according to any one of claims 1 to 6 ,
After the sheet is heated and dried inside the drying chamber, the sheet is conveyed in a direction different from the conveying direction of the sheet in the drying chamber along a path along the drying chamber. Drying equipment to do. A method of drying a sheet comprising an absorbent article and having an image inkjet printed thereon,
Supplying the sheet to the outer peripheral surface of the drum provided in the drying chamber so that the printing surface of the sheet faces outward, and holding the sheet on the outer peripheral surface of the drum, Conveying the sheet by rotating;
And
A blower outlet for blowing out the drying air at a position facing the outer peripheral surface is provided,
A vent hole is formed in the outer peripheral surface of the drum,
Passing the drying air in the thickness direction of the sheet through the vent hole ,
The sheet that has passed through the drum is further dried using another drum,
In the transport path between the drum and the other drum, a roller contacts the semi-dried printing surface of the sheet, and changes the transport direction of the sheet,
The drying method, wherein the other drum further dries the sheet while holding and transporting the sheet so that a printing surface of the sheet faces outward .

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