JP5799191B1 - Composite sheet manufacturing apparatus and composite sheet manufacturing method - Google Patents

Abstract

It is a manufacturing apparatus of a sheet member, Comprising: The 1st conveyance roller conveyed in a conveyance direction, supporting the said sheet member, The 2nd conveyance provided in the downstream of the said conveyance direction rather than the said 1st conveyance roller A transport unit having a roller, a support roller provided between the first transport roller and the second transport roller and supporting the sheet member, the first transport roller, and the second transport A printing unit that prints an image by ejecting ink droplets onto the sheet member from an ink ejection device disposed between the roller and a position where the first conveying roller supports the sheet member The position where the support roller supports the sheet member is higher, and the support roller is more than the position where the second transport roller supports the sheet member. The sheet member is supported at a higher position, and at least one of the first transport roller and the second transport roller is changed in inclination of a rotation axis in a horizontal plane, thereby skewing the sheet member. Is adjusted.

Description

The present invention relates to a composite sheet manufacturing apparatus and a composite sheet manufacturing method.

  In a paper diaper as an absorbent wearing article, in order to improve the design on the appearance or make it easy to distinguish the front and back of the diaper at a glance, a pattern or a letter is attached to the outer member of the diaper. When manufacturing such a diaper, it is common to comprise a diaper using the base material sheet on which images, such as a character, were printed beforehand. For example, in Patent Document 1, a predetermined color design is printed on the entire area of an interior sheet (base material sheet) that covers the back surface of a paper diaper so that the color design can be viewed from the outside of the diaper. An invention relating to a disposable diaper capable of giving an impression like underwear is described.

JP 2003-70838 A

Inkjet printing is known as a method for printing an image with good image quality on a diaper. In inkjet printing, an ink droplet is ejected from a printing device and landed on a base sheet (for example, a nonwoven fabric) that forms a diaper, whereby an image is printed on a landing portion of the ink droplet.
When performing inkjet printing on a diaper production line that continuously manufactures diapers, ink droplets are ejected from the inkjet printer installed on the transport path to the base sheet while transporting the base sheet of the diaper in the transport direction. The method of making it known is known. However, in such a printing method, if the base sheet flutters in the conveyance process or the conveyance direction is skewed, the landing positions of the ink droplets may be shifted, and the image quality of the printed image may be deteriorated. There is.

  The present invention has been made in view of the above problems, and the object of the present invention is to stably provide a sheet member when inkjet printing an image on the sheet member in an absorbent article production line. It is to carry.

The main invention for achieving the above object is:
An apparatus for manufacturing a composite sheet according to an absorbent article,
The composite sheet is less stretchable than the stretchable sheet, which forms an inner layer facing the wearer's skin when wearing the absorbent article, and an outer layer facing the non-skin side when worn. Having a sheet member as a low stretch sheet,
The manufacturing apparatus includes :
An end plate made of a plate material standing upright in a direction perpendicular to the horizontal plane;
A first conveyance roller that conveys the sheet member in a conveyance direction while supporting the sheet member; a second conveyance roller that is provided downstream of the first conveyance roller in the conveyance direction; and the first conveyance roller And a support roller provided between the second transport roller and supporting the sheet member, and a transport unit,
A printing unit that prints an image by ejecting ink droplets onto the sheet member from an ink ejection device disposed between the first transport roller and the second transport roller;
A drying section provided on the downstream side in the transport direction of the second transport roller;
A sheet member joining portion that is provided on the downstream side in the transport direction of the drying unit, and that joins the stretchable sheet to a surface opposite to the printing surface of the sheet member;
With
The position where the support roller supports the sheet member is higher than the position where the first transport roller supports the sheet member, and the position where the second transport roller supports the sheet member. The position where the support roller supports the sheet member is higher,
The center position in the orthogonal direction perpendicular to the transport direction of the nozzle row provided in the printing unit overlaps the virtual center line set at a position away from the surface of the end plate by a predetermined distance,
For at least one of the first transport roller and the second transport roller, the skew of the sheet member is adjusted by changing the inclination of the rotation axis in the horizontal plane,
The drying section, the composite sheet wherein while the printing surface of the sheet member is passed through a drying chamber while sucking and holding the side opposite, blowing air toward the printing surface of the sheet member, it is characterized by It is a manufacturing apparatus.
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, when carrying out the inkjet printing of the image on a sheet | seat member in the production line of an absorbent article, it becomes possible to print an image with a good image quality by stably conveying the sheet member.

It is a schematic perspective view of the underpants type diaper 1 as an example of the absorbent article which concerns on this embodiment. It is the schematic plan view which looked at the diaper 1 of the unfolding state from the skin side. It is a schematic perspective view which decomposes | disassembles and shows the diaper 1 of an unfolding state. It is a schematic side view of the production line LM which manufactures the exterior sheet 7 which comprises the diaper 1. 2 is a side view illustrating a configuration of a head unit 12 of a printing unit 10. FIG. It is a figure explaining arrangement of head unit 121 and nozzle Nz. It is process explanatory drawing after the production | generation of the exterior continuous sheet 7A until completion of the diaper 1. FIG. 3 is an enlarged side view of a region of a printing unit 10 in a production line LM. It is the figure expanded and represented about the area | region M of FIG. 10A to 10C are diagrams for describing a method of setting the transport position in the production line LM. 11A and 11B are diagrams for describing a method of adjusting the skew (skew to the left side) of the low-extension continuous sheet 9A in the printing section. 12A and 12B are diagrams for describing a method of adjusting the skew (skew to the right) of the low-extension continuous sheet 9A in the printing section. 13A and 13B are diagrams specifically illustrating a method of changing the inclination of the rotation axis in the horizontal plane of the first transport roller CVp1.

At least the following matters will become apparent from the description of the present specification and the accompanying drawings.
An apparatus for manufacturing a sheet member according to an absorbent article, wherein the sheet member is provided on a downstream side in the transport direction with respect to a first transport roller that transports the sheet member in a transport direction while supporting the sheet member. A transport unit having a second transport roller, a support roller provided between the first transport roller and the second transport roller and supporting the sheet member, and the first transport roller, A printing unit that prints an image by ejecting ink droplets onto the sheet member from an ink ejection device disposed between the second conveyance roller and the first conveyance roller being the sheet member The position where the support roller supports the sheet member is higher than the position where the support roller supports the sheet member, and the support roller is higher than the position where the second transport roller supports the sheet member. The position where the roller supports the sheet member is higher, and the inclination of the rotation axis in the horizontal plane is changed with respect to at least one of the first conveyance roller and the second conveyance roller. An apparatus for manufacturing a sheet member, wherein skew feeding is adjusted.

  According to such a sheet member manufacturing apparatus, when an image is inkjet printed on a sheet member in an absorbent article manufacturing line, an appropriate tension is applied in the conveyance direction while preventing the sheet member from skewing. Thus, the sheet member can be stably conveyed. As a result, the landing positions of the ink droplets are difficult to shift, and an image with good image quality can be printed.

In this sheet member manufacturing apparatus, the transport unit includes a first support roller, a second support roller, and a third support roller arranged along the transport direction,
The position where the second support roller supports the sheet member is higher than the position where the first support roller supports the sheet member, and the third support roller supports the sheet member. It is desirable that the position where the second support roller supports the sheet member is higher than the position.

  According to such a sheet member manufacturing apparatus, a force in the thickness direction acts on the sheet member at a support point designated by the support roller, so that the sheet member can be conveyed while applying an appropriate tension. Therefore, the sheet member is prevented from being loosened or fluttering up and down during conveyance. This makes it easy to print an image with good image quality.

  In this sheet member manufacturing apparatus, the printing unit includes a plurality of head units that discharge the ink droplets from the nozzles along the transport direction, and the support roller includes two different adjacent ones in the transport direction. It is preferable that the sheet member is provided at a position between the head units, and the sheet member is supported by being supported between the plurality of support rollers.

  According to such a sheet member manufacturing apparatus, since the support interval in the conveyance direction of the sheet member is shortened, the sheet member being conveyed is hardly bent. Since printing is performed between the sheet members stretched between the support rollers, the landing positions of the ink droplets are less likely to shift, and it becomes easier to print an image with good image quality.

  In this sheet member manufacturing apparatus, the sheet member has an inclination of a predetermined angle with respect to a horizontal plane in at least a partial region between the first transport roller and the second transport roller. The head unit is arranged such that the nozzle surface is inclined according to the inclination so that the nozzle surface in which a plurality of the nozzles are arranged on the same plane and the sheet member are parallel to each other. It is desirable that

  According to such a sheet member manufacturing apparatus, the distance between each of the plurality of nozzles provided on the nozzle surface of the head unit and the sheet member becomes equal. That is, the distance from the ejection of ink droplets from each nozzle to the landing on the sheet member becomes equal. This makes it difficult for the landing positions of the ink droplets to shift and makes it easy to print an image with good image quality. In addition, since it is not necessary to adjust the height for each of the plurality of heads (nozzle rows) provided in the head unit, complicated adjustment work is not required.

  In this sheet member manufacturing apparatus, it is preferable that the support roller is disposed at a position not facing a nozzle row provided in the printing unit.

  According to such a sheet member manufacturing apparatus, ink droplets ejected from nozzles (nozzle rows) are prevented from penetrating the sheet member in the thickness direction and adhering to the support roller. Thereby, the outer peripheral surface of a support roller becomes difficult to be contaminated with ink.

  In the sheet member manufacturing apparatus, it is preferable that the support roller is rotationally driven by receiving power from a power source.

  According to such a sheet member manufacturing apparatus, since the force for conveying the sheet member in the conveying direction can be distributed and acted on the plurality of support points, a local force is exerted on the sheet member. The concentrated action is suppressed, and the sheet member can be more stably conveyed.

  The sheet member manufacturing apparatus preferably includes a cleaning mechanism that contacts the outer peripheral surface of the support roller and removes ink adhering to the outer peripheral surface.

  According to such a sheet member manufacturing apparatus, even when ink adheres to the outer peripheral surface of the support roller, the sheet member is contaminated by the ink adhered to the support roller by performing cleaning. Can be suppressed.

  In this sheet member manufacturing apparatus, an apparatus that performs a predetermined process on the sheet member is provided on the downstream side in the transport direction of the second transport roller, and the first transport roller It is desirable that the skew of the sheet member is adjusted by changing the inclination of the rotation axis in the horizontal plane.

  According to such a sheet member manufacturing apparatus, since the skew of the sheet member on the downstream side in the conveyance direction can be suppressed by the first conveyance roller disposed on the upstream side in the conveyance direction, the conveyance direction downstream of the second conveyance roller. Stable conveyance can be performed on the side, that is, a position where an apparatus for performing a predetermined process is arranged.

  In this sheet member manufacturing apparatus, the length of the sheet member wound around the second conveying roller is longer than the length of the sheet member wound around the first conveying roller in the conveying unit. The longer one is desirable.

  According to such a sheet member manufacturing apparatus, a larger frictional force acts on the sheet member on the second conveyance roller side than the first conveyance roller. Thereby, since it becomes easy to transmit the rotational force of a 2nd conveyance roller to a sheet member more efficiently, a sheet | seat member is stabilized more stably in the conveyance direction downstream of the 2nd conveyance roller in which the predetermined | prescribed apparatus is provided. It can be transported.

  Moreover, conveying in the said conveyance direction, supporting the sheet | seat member which concerns on an absorbent article with the 2nd conveyance roller provided in the downstream of the conveyance direction rather than the 1st conveyance roller and the said 1st conveyance roller, Supporting the sheet member by a support roller provided between the first conveyance roller and the second conveyance roller, and between the first conveyance roller and the second conveyance roller. A method for producing a sheet member, comprising: ejecting ink droplets from a disposed ink ejection device onto the sheet member to print an image, wherein the first conveying roller supports the sheet member. The position where the support roller supports the sheet member is higher than the position, and before the position where the second transport roller supports the sheet member. The position where the support roller supports the sheet member is higher, and the sheet member is changed by changing an inclination of a rotation axis in a horizontal plane for at least one of the first conveyance roller and the second conveyance roller. The sheet member manufacturing method is characterized in that the skew is adjusted.

  According to such a method for producing a sheet member, when an image is printed on the sheet member by inkjet printing on the absorbent article production line, an appropriate tension is applied in the conveyance direction while preventing the sheet member from skewing. Thus, the sheet member can be stably conveyed. As a result, the landing position of the ink droplets is difficult to shift, and a sheet member on which an image with good image quality is printed can be manufactured.

=== Embodiment ===
First, a basic structure of a pants-type diaper 1 (hereinafter also simply referred to as “diaper 1”) and a sheet member production line LM will be described as an example of an absorbent article formed by the sheet member according to the present embodiment.

<Basic structure of diaper 1>
FIG. 1 is a schematic perspective view of a pant-type diaper 1. FIG. 2 is a schematic plan view of the unfolded diaper 1 as seen from the skin side. FIG. 3 is a schematic perspective view showing the exploded diaper 1 in an exploded state. In the following description, when the diaper 1 is attached to the wearer, the side that should be located on the skin side of the wearer is simply referred to as “skin side”, and on the other hand, the side that is located on the non-skin side of the wearer. The power side is simply called the “non-skin side”.

  The diaper 1 is a so-called two-piece type diaper. That is, the diaper 1 has an absorbent main body 3 that absorbs excreted fluid such as urine as a first component. And the non-skin side surface of the absorptive main body 3 is provided, and it has the planar view substantially hourglass-shaped exterior sheet 7 which makes the exterior of the diaper 1 as a 2nd component.

  The absorptive main body 3 has an absorptive core 3c that absorbs excretory fluid. The absorptive core 3c is formed by molding liquid absorptive fibers such as pulp fibers and liquid absorptive granular materials such as superabsorbent polymers into a predetermined shape (for example, a rectangular shape). The skin side surface of the absorbent core 3c is provided with a liquid-permeable top sheet 4 such as a nonwoven fabric so as to cover the surface. Similarly, the non-skin side surface of the absorbent core 3c is provided with the surface. A liquid-impermeable leak-proof sheet 5 such as a film is provided so as to cover the entire surface.

  The exterior sheet 7 is a flexible sheet having a substantially hourglass shape in plan view in the unfolded state of FIG. 2, and the sheet 7 has a thickness direction, a longitudinal direction, and a width direction as three directions orthogonal to each other. ing. The exterior sheet 7 is divided into three portions 7f, 7b, and 7c with respect to the longitudinal direction. That is, the exterior sheet 7 is formed on an abdominal side portion 7f disposed on the wearer's belly side, a back side portion 7b disposed on the wearer's back side, and a crotch portion 7c disposed on the wearer's crotch. It is divided.

  As shown in FIG. 3, a so-called laminate sheet having a two-layer structure is used for the exterior sheet 7. That is, the exterior sheet 7 is a composite sheet having an inner layer sheet 8 that forms an inner layer facing the wearer's skin when the diaper 1 is worn, and an outer layer sheet 9 that forms an outer layer facing the non-skin side when the diaper 1 is worn. is there. The inner layer sheet 8 and the outer layer sheet 9 are bonded together by adhesion or welding while being overlapped in the thickness direction. In this example, the joining portion between the inner layer sheet 8 and the outer layer sheet 9 is welded with a predetermined joining pattern (not shown) formed by discontinuous dispersion.

  As the material for the inner layer sheet 8, a stretchable sheet 8 having stretchability in the width direction of the diaper 1 is used. On the other hand, as the material for the outer layer sheet 9, low stretchability is low in the width direction of the diaper 1. An extensible sheet 9 is used. And in the state where the stretchable inner layer sheet 8 is stretched in the width direction to a predetermined stretch ratio such as 2.5 times the natural length (hereinafter also referred to as the stretched state), the stretch is also low stretch in the state stretched in the width direction. The sheet 8 and 9 are superposed on the outer layer sheet 9 and fixed integrally with the above-mentioned bonding pattern.

  Therefore, when the stretched state is released, the inner layer sheet 8 shrinks in the width direction of the diaper 1 based on its own stretchability. At this time, the low stretchable outer layer sheet 9 has a plurality of hooks. The diaper 1 is bent in the width direction, whereby the outer layer sheet 9 quickly follows the contraction of the inner layer sheet 8 to shorten the entire length in the width direction. As a result, in an unloaded state where no external force acts on the diaper 1, the outer sheet 7 is shortened in the width direction as a whole, and the outer surface of the outer sheet 7 is caused by bending of the outer layer sheet 9. It is in a state where there are multiple wings. However, when an external force is applied to the exterior sheet 7 in the width direction, the exterior sheet 7 can be stretched approximately elastically until the wrinkle is fully extended, whereby the exterior sheet 7 of the diaper 1 It has become a specification with elasticity.

  Incidentally, the term “stretchability” as used herein 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. is there.

  The stretchable sheet 8 desirably satisfies the following conditions. That is, in the state where both ends in the longitudinal direction of the belt-like sheet having a short dimension of 25 mm are equally gripped with the total length of 25 mm in the short direction, the both ends are each 1.0 (N) as a power point. The elongation (%) when pulled in the longitudinal direction by an external force is an arbitrary value in the range of 50% to 300%, and the residual elongation strain (%) that remains without contracting after the external force is released and contracted However, it is good that it is an arbitrary value in the range of 0% to 40%. More desirably, the elongation percentage is an arbitrary value in the range of 70% to 200%, and the residual elongation strain is an arbitrary value in the range of 0% to 30%. Incidentally, the above-mentioned elongation rate (%) is the natural length L0, which is the length of the belt-like sheet at the time of no load before being pulled, from the length L1 of the belt-like sheet when pulled with an external force of 1.0 (N). Is a percentage notation value of a division value (= ΔL1 / L0) obtained by dividing a subtraction value ΔL1 (= L1−L0) obtained by subtracting the value by the natural length L0. The residual elongation strain (%) is a subtracted value ΔL2 (= L2) obtained by subtracting the natural length L0 before pulling from the length L2 after releasing the external force of 1.0 (N). -L0) is a percentage of the division value (= ΔL2 / ΔL1) obtained by dividing the natural length L0 by the subtraction value ΔL1 (= L1−L0) obtained by subtracting the natural length L0 from the length L1 when pulled by the external force. It is a written value.

  Further, the “low extensible sheet 9” is an extensible sheet lower than the stretchable sheet 8 described above. That is, the stretch rate (%) when an external force of a predetermined amount of tension is applied is lower than the stretch rate (%) of the stretchable sheet 8 described above. Note that the low-extensible sheet 9 desirably satisfies the following conditions. That is, in the state where both ends in the longitudinal direction of the belt-like sheet having a short dimension of 25 mm are equally gripped with the total length of 25 mm in the short direction, the both ends are each 1.0 (N) as a power point. The elongation (%) when pulled in the longitudinal direction by an external force is preferably an arbitrary value in the range of 0% to 20%. More preferably, the elongation rate is an arbitrary value in the range of 0% to 10%.

  In this embodiment, the elastic sheet 8 and the low extensibility sheet 9 are demonstrated as what is comprised with the nonwoven fabric. However, the stretchable sheet 8 and the low stretchable sheet 9 may be composed of other sheets such as woven fabric.

  About the specific example of the nonwoven fabric which can be utilized for the elastic sheet 8, it is appropriate to perform a gear stretching process or the like on a nonwoven fabric having a thermoplastic elastomer fiber exhibiting substantially elasticity and a thermoplastic resin fiber exhibiting substantially inelasticity. Examples of the nonwoven fabric subjected to various stretching treatments. That is, by performing such stretching treatment, if the substantially inelastic thermoplastic resin fibers contained in the nonwoven fabric are plastically deformed or the joints between the fibers are destroyed, the substantially elastic properties of the thermoplastic elastomer fibers can be reduced. The non-woven fabric can be changed to a structure that hardly inhibits general stretch deformation, whereby the stretchability of the non-woven fabric is expressed and the stretchable sheet 8 can be used.

  Since such a stretchable sheet 8 is configured in a state where a plurality of fibers are randomly entangled, when viewed microscopically, the stretchable sheet 8 has a structure having a plurality of voids between the fibers. . And on the surface, there are a portion where the fibers are intertwined closely and a portion where the fibers are intertwined roughly. In other words, the stretchable sheet 8 has a structure having a density. Therefore, even when both ends of the elastic 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 is partially dense. Becomes larger, and a portion where the gap becomes larger is generated.

  Specific examples of the nonwoven fabric that can be used for the low-extension sheet 9 include spunbond nonwoven fabric, meltblown nonwoven fabric, spunbond nonwoven fabric, meltblown nonwoven fabric, and spunbond nonwoven fabric made of fibers such as PE, PP, polyester, and polyamide. The so-called SMS nonwoven fabric, air-through nonwoven fabric and the like can be exemplified. The fiber structure is not limited to a single fiber made of a single thermoplastic resin as described above. The low-extension sheet 9 also has a structure having a plurality of voids between entangled fibers.

  As shown in FIG. 3, the absorbent main body 3 is joined at the joint J on the skin side of the exterior sheet 7. And the exterior sheet | seat 7 to which the absorptive main body 3 was attached is folded in half by the crotch part 7c, and the abdominal side part 7f and the back side part 7b are overlapped. Then, in this overlapped state, the abdomen side portion 7f and the back side portion 7b are joined at the respective end portions 7eW in the width direction, so that the waist opening HB as shown in FIG. It is made into the form of the underpants type diaper 1 in which the leg periphery opening parts HL and HL were formed.

  In the pants-type diaper 1 of the present embodiment, an image G made up of predetermined characters, patterns, characters, etc. is printed on the exterior sheet 7 (see FIG. 1). The image G improves the design on the appearance of the diaper 1 and allows 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. 4 is a schematic side view of a production line LM for producing the exterior sheet 7 constituting the diaper 1. The production line LM uses as a material a continuous sheet 8A of the stretchable sheet 8 (hereinafter also referred to as a stretchable continuous sheet 8A) and a continuous sheet 9A of a low stretchable sheet 9 (hereinafter also referred to as a low stretchable continuous sheet 9A). Thus, a continuous sheet 7A in which the exterior sheet 7 is continuous in the width direction (hereinafter also referred to as an exterior continuous sheet 7A) is generated. The production line LM includes a transport mechanism CV, a printing unit 10, a drying unit 30, and a sheet member joining unit 50.

  The conveyance mechanism CV is a conveyance unit that continuously conveys the stretchable continuous sheet 8A (interior sheet 8), the low-extension continuous sheet 9A (exterior sheet 9), or both along a predetermined conveyance path. As the transport mechanism CV, for example, a transport roller, a suction belt conveyor having a suction holding function on a belt surface as a placement surface, or the like is used. In the transport mechanism CV of the present embodiment, the low-extension continuous sheet 9A is transported in a line in the transport direction while aligning the direction corresponding to the width direction of the diaper 1 with the transport direction. Similarly, the stretchable continuous sheet 8A is also transported in a line in the transport direction while aligning the direction corresponding to the width direction of the diaper 1 with the transport direction.

  Further, in the following description, the above-described transport direction set on 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. One of the two directions orthogonal to the MD direction may be referred to as a “CD direction”, and the other may be referred to as a “Z direction”. The CD direction is a direction parallel to the width direction of each sheet, and is a direction perpendicular to the paper surface of FIG. The Z direction is a direction parallel to the thickness direction of each sheet.

(Printer 10)
The printing unit 10 prints the image G on the low-extension continuous sheet 9A in the process in which the low-extension continuous sheet 9A is conveyed downstream in the MD direction by the conveyance mechanism CV. The printing unit 10 of the present embodiment is an ink ejection device (inkjet printing device) that ejects ink droplets from a large number of nozzles Nz and forms an image G by ink droplets (dots) landed on the low-extension continuous sheet 9A. . The printing unit 10 includes a head unit 12 and a printing control unit 13. FIG. 5 is a side view illustrating the configuration of the head unit 12 of the printing unit 10. FIG. 6 is a diagram illustrating the arrangement of the head unit 121 and the nozzles Nz.

  The head unit 12 is an ink ejection unit that has a plurality of nozzles Nz arranged in the CD direction and ejects ink droplets from each nozzle Nz. In the printing unit 10 of the present embodiment, four head units 12 are arranged along the MD direction, and each head unit 12 ejects yellow ink, magenta ink, cyan ink, and black ink, respectively. The head unit 12 may be capable of ejecting a plurality of colors of ink. Further, the number of head units 12 arranged is not limited to four.

  Each head unit 12 has a plurality of heads 121 arranged along the MD direction. In the example of FIG. 6, four heads 121 are arranged along the MD direction. The head 121 has a plurality of short heads 121s arranged in a staggered pattern along the CD direction. In the example of FIG. 6, four short heads 121s are arranged along the CD direction. The number of heads 121 provided in one head unit 12 and the number of short heads 121s provided in one head 121 are not limited to the example in FIG. Each short head 121s has a plurality of nozzles Nz arranged in the CD direction. Thereby, the head unit 12 can discharge ink with respect to the whole area | region of the width direction of 9 A of low extensible continuous sheets which are printing media. In addition, each nozzle Nz is arrange | positioned on the same plane of the lower end part of the head unit 12, and it can discharge an ink drop from the same position (height) of the thickness direction with respect to the low extensibility continuous sheet 9A. It has become. A plane on which the nozzles are arranged in the head unit 12 of the printing unit 10 is also referred to as a nozzle surface (see FIG. 5). The ink droplet ejection method by the head 121 may be a piezoelectric method using a piezoelectric element, a thermal method using a heater, or another method.

  The print control unit 13 is a control unit that controls the operation of the printing unit 10. For example, the print control unit 13 controls the ejection timing and ejection amount of ink droplets ejected from the nozzles Nz of the head unit 12 by controlling the head unit 12.

(Drying section 30)
The drying unit 30 is provided downstream of the printing unit 10 in the MD direction, and dries the ink by blowing dry air onto the extensible continuous sheet 9A on which the image G is printed. The drying unit 30 includes a drying chamber 31, a conveyor belt 32, a plurality of air outlets 33, and a pressurizing chamber 34 (see FIG. 4).

  The inside of the drying chamber 31 is kept at a high temperature, and the low-extension continuous sheet 9A is blown with dry air when passing through the drying chamber 31 while being held by the conveyance belt 32. The dry air is air that has been dehumidified and heated to a predetermined temperature (for example, about 80 °), is supplied from the pressurization chamber 34, and is ejected from the blowout port 33. The air outlet 33 is a slit-like opening in which an opening having a predetermined width in the MD direction extends in the CD direction, and uniform dry air (heating air) in the thickness direction toward the low-extension continuous sheet 9A. Can be erupted. In the drying unit 30 of the present embodiment, as shown in FIG. 4, the plurality of air outlets 33 are opposed to the surface on which the image of the low-extension continuous sheet 9 </ b> A is printed (hereinafter also referred to as a printing surface). It can arrange | position and can spray dry air toward a printing surface. The dry air ejected from each outlet 33 flows from the lower side to the upper side in the thickness direction so as to penetrate the low-extension continuous sheet 9A, and heats the ink to the inside of the low-extension continuous sheet 9A. dry. At that time, the closer to the printing surface, the more ink is attached to the fibers. Therefore, the ink can be efficiently dried by blowing dry air from the printing surface side. However, dry air may be blown from the opposite side (that is, from the upper side to the lower side).

  The drying unit 30 may have other configurations. For example, while holding the low extensibility continuous sheet 9A on the outer peripheral surface of the rotating drum, the low extensibility continuous sheet is sucked into the drum from the air blown from a plurality of outlets arranged around the drum. A drum-type drying device that allows dry air to pass in the thickness direction of the sheet 9A may be used.

(Sheet member joint 50)
The sheet member joining section 50 superimposes and joins the stretchable continuous sheet 9A on which the image G is printed with the stretchable continuous sheet 8A in the thickness direction to generate the exterior continuous sheet 7A. The sheet member joining portion 50 is an ultrasonic welding device having an anvil roller 51 and an ultrasonic horn 52 (see FIG. 4).

  The anvil roller 51 includes a stretchable continuous sheet 8A that is 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 tension that does not cause plastic deformation). And a low-extension continuous sheet 9 </ b> A in a state in which is provided. The stretchable continuous sheet 8A and the low stretchable continuous sheet 9A are wound around the outer peripheral surface of the anvil roller 51 in a state where the stretchable continuous sheet 8A and the low stretchable continuous sheet 9A are overlapped in the thickness direction. The extensible continuous sheet 9A is welded when passing through the ultrasonic horn 52, and the exterior continuous sheet 7A is generated.

  As shown in FIG. 4, in this embodiment, the stretchable continuous sheet 8 </ b> A is bonded to the surface opposite to the printing surface (the surface on which the image is printed) of the low stretchable continuous sheet 9 </ b> A. Thereby, poor welding due to ink can be suppressed, and the bonding strength between the stretchable continuous sheet 8A and the low stretchable continuous sheet 9A can be kept strong. The printing surface of the low-extension continuous sheet 9A is disposed on the opposite side of the stretchable continuous sheet 8A, so that the printing surface of the low-extension continuous sheet 9A is the non-skin side of the exterior sheet 7 of the diaper 1, that is, Since it is arranged on the outermost surface (outermost surface) of the diaper 1 (see FIG. 3), the image G of the exterior sheet 7 of the diaper 1 can be visually recognized in a colorful manner.

  FIG. 7 is a process explanatory diagram from the generation of the exterior continuous sheet 7 </ b> A to the completion of the diaper 1. The production line LM forms an opening in the exterior continuous sheet 7A that serves as a leg-hole opening HL (see FIG. 1). 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 that has been conveyed in the stretched state is contracted in the MD direction. Thereby, wrinkles are 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. An end seal portion (end portion 7eW in FIG. 1) is formed by welding in the CD direction from the leg opening HL of the exterior continuous sheet 7A folded in half, and the exterior continuous sheet 7A is divided and separated by the end seal portion. Part becomes diaper 1.

<About the media transport operation during printing>
A conveyance operation when printing the image G on the low-extension continuous sheet 9A in the production line LM will be described. As described above, the printing unit 10 performs ink jet printing by ejecting ink droplets to land on the low-extension continuous sheet 9A conveyed in the MD direction. At this time, if the stretchable continuous sheet 9A being conveyed vibrates up and down in the thickness direction, or if the conveying direction is skewed, the landing positions of the ink droplets shift and the image quality of the printed image deteriorates. There is a risk. Therefore, in order to print an image with good image quality, the low-extension continuous sheet 9A needs to be stably conveyed along the conveyance direction.

  FIG. 8 is an enlarged side view of the area of the printing unit 10 in the production line LM. FIG. 9 is an enlarged view of the region M in FIG. In the following description, a section surrounded by a broken line in FIG. 8 in the production line LM is also referred to as a “print section” for convenience. In the printing section, the low-extension continuous sheet 9A is provided by the first transport roller CVp1 of the transport mechanism CV and the second transport roller CVp2 provided on the downstream side in the transport direction (MD direction) from the first transport roller CVp1. It is conveyed in the MD direction. Both the first transport roller CVp1 and the second transport roller CVp2 are rotationally driven by a driving force of a motor (not shown), thereby transporting the low-extension continuous sheet 9A to the downstream side in the MD direction at a predetermined speed. . In the present embodiment, the outer diameter D2 of the second transport roller CVp2 is larger than the outer diameter D1 of the first transport roller CVp1 (D2> D1). The reason for this will be described later. A printing unit 10 (ink ejection device) is disposed between the first conveyance roller CVp1 and the second conveyance roller CVp2, and inkjet printing is performed while the low-extension continuous sheet 9A is conveyed through the printing section. .

  Further, a plurality of support rollers for supporting the low extensibility continuous sheet 9A are provided between the first transport roller CVp1 and the second transport roller CVp2. In the example of FIG. 8, a first support roller Sr1, a second support roller Sr2, and a third support roller Sr3 are provided along the MD direction. In the present embodiment, the height (vertical height) of the position where each support roller supports the low-stretch continuous sheet 9A is higher than the height of the position where the first transport roller CVp1 supports the low-stretch continuous sheet 9A. It is high. Similarly, the height (vertical height) at which each support roller supports the low-stretch continuous sheet 9A is higher than the height at which the second transport roller CVp2 supports the low-stretch continuous sheet 9A. ing.

  For example, in FIG. 8, the point at which the low-stretch continuous sheet 9A is supported by the first transport roller CVp1 is a support point S1, and the point at which the low-stretch continuous sheet 9A is supported by the second transport roller CVp2 is a support point S2. . Further, the point where the low extensibility continuous sheet 9A is supported by the first support roller Sr1 is a support point S3, and the point where the low extensibility continuous sheet 9A is supported by the second support roller Sr2 is a support point S4. A point where the low-extension continuous sheet 9A is supported by Sr3 is defined as a support point S5. In this case, the heights of the support points S3, S4 and S5 are higher than the height of the support point S1 and higher than the height of the support point S2. Further, the height of the support point S4 is higher than the height of the support point S3 and higher than the height of the support point S5.

  Thereby, the conveyance path | route of the low extensibility continuous sheet 9A between the 1st conveyance roller CVp1 and the 2nd conveyance roller CVp2 (namely, printing section) became the arch shape which became convex upwards vertically as shown in FIG. It becomes. Assuming that each support point is the same height and the low stretchable continuous sheet 9A is transported through the printing section in a horizontally supported state, a force in the thickness direction is applied to the low stretchable continuous sheet 9A. When it acts, there is a possibility that the low-extensible continuous sheet 9A being conveyed is slackened or fluttered vertically. On the other hand, if the low extensibility continuous sheet 9A is supported in an arch shape as shown in FIG. 8, the tension in the MD direction acts between the support points S1 and S2 on the low extensibility continuous sheet 9A. In addition to this, a force including a component on the upper side in the vertical direction (force in the thickness direction) is applied by the support points S3 to S5. As a result, moderate tension acts on the low-extension continuous sheet 9A throughout the printing section to suppress loosening and flapping during conveyance, so that the low-extension continuous sheet 9A can be stably conveyed. Become.

  As shown in FIG. 8, the support rollers Sr <b> 1 to Sr <b> 3 are respectively disposed between two different head units 12 and 12 that are arranged adjacent to each other in the MD direction. That is, the low extensibility continuous sheet 9A is conveyed in the MD direction while being supported so as to be bridged between the support rollers. Thereby, since the support space | interval in the MD direction of the low extensibility continuous sheet 9A becomes short, it becomes easy to suppress that the extensibility continuous sheet 9A in conveyance is produced. And since printing is performed by the head unit 12 at a position between the MD directions of the low stretchable continuous sheet 9A supported by being supported between two support rollers, the landing positions of the ink droplets are difficult to shift, It becomes easy to print an image of good quality.

  Furthermore, the number of support rollers arranged in the printing section may be increased. For example, in FIG. 9, three support rollers Sr4, Sr5, and Sr6 are provided between the first support roller Sr1 and the second support roller Sr2. By increasing the number of support rollers, the interval between the support positions in the MD direction of the low-extension continuous sheet 9A becomes shorter, so that it is possible to make it difficult to cause bending. In FIG. 9, the support rollers Sr4, Sr5, and Sr6 are all arranged at positions that do not face the nozzle row (head 121) of the head unit 12. This is because the low-extension continuous sheet 9A is a nonwoven fabric, and thus ink droplets are prevented from passing between the fibers of the nonwoven fabric and adhering to the support roller.

  However, even when the support roller is arranged at a position not facing the nozzle row in this way, a part of the ink droplets landed on the printing surface is thicker from the printing surface side to the opposite side of the low-extension continuous sheet 9A. In some cases, the surface of the support roller (outer peripheral surface) may be contaminated by ink. Therefore, a cleaning mechanism for removing ink attached to the outer peripheral surface of the support roller may be provided for each support roller. In the example of FIG. 9, the cleaning mechanism 40 is provided on the lower side in the vertical direction of each support roller. The cleaning mechanism 40 includes a wiping unit 41 that wipes off ink adhering to the outer peripheral surface of the support roller, and a moving unit 42. The wiping portion 41 is a cloth-like or brush-like cleaning portion extending in the CD direction, and is moved up and down in the vertical direction by the moving portion 42. The wiping portion 41 is normally disposed at a position where it does not come into contact with each support roller, and moves so as to come into contact with the outer peripheral surface of the support roller regularly or irregularly, and ink stains adhered to the outer peripheral surface. Wipe off. For example, the support roller is cleaned after a printing operation is continuously performed for a predetermined time or at an arbitrary timing. Thereby, it is suppressed that the low extensibility continuous sheet 9A is contaminated by the ink adhering to the support roller. Moreover, since the wiping part 41 and each support roller are not contacting at the time of normal conveyance, the conveyance operation | movement of 9 A of low extensible continuous sheets is hard to be prevented.

  In addition, these support rollers (Sr1 to Sr5) may be driven to rotate by receiving power from a power source such as a motor to convey the low-extension continuous sheet 9A in the MD direction. If it does in this way, since the force which conveys low extensibility continuous sheet 9A to MD direction can be made to act in a plurality of supporting points in a printing section, it can be made to act on low extensibility continuous sheet 9A. Accordingly, the concentrated local force is suppressed and the low-extension continuous sheet 9A can be more stably conveyed. However, each support roller may be passively rotated by contacting the low-extension continuous sheet 9A.

  In the present embodiment, the installation angle of the head unit 12 of the printing unit 10 is adjusted according to the conveyance path of the low-extension continuous sheet 9A. Specifically, each head unit 12 is transported so that the nozzle surface of the head unit 12 is substantially parallel to the surface of the low-extension continuous sheet 9A that is transported while being inclined in an arch shape in the printing section. It is installed along the slope of For example, in FIG. 9, the low-extension continuous sheet 9A is supported between the first support roller Sr1 and the second support roller Sr2 so as to have an angle α with respect to the horizontal plane. In this case, the head unit 12 is also installed at an angle α with respect to the horizontal plane along the inclination. As a result, the distances between the nozzles Nz of the four heads 121, 121, 121, 121 arranged in the MD direction and the low-extension continuous sheet 9A are equal. Supposing that the nozzle surface of the head unit 12 is horizontally arranged, the head 121 arranged on the most upstream side in the MD direction and the head 121 arranged on the most downstream side in the MD direction have a low nozzle Nz. The distance between the stretchable continuous sheet 9A will be different. That is, since the flying distances of the ejected ink droplets are different, the landing positions of the ink droplets are liable to shift. On the other hand, by arranging the nozzle surface of the head unit 12 so as to be inclined according to the inclination of the conveyance path as shown in FIG. The distance to do is equal. Therefore, landing deviation of ink droplets is suppressed, and it becomes easy to print an image with good image quality. Further, since it is sufficient to install the head unit 12 at an angle, complicated adjustment work such as height adjustment for each head 121 is unnecessary.

  On the other hand, if the inclination of the nozzle surface is too large, it may be difficult to land the ink droplet at an accurate position due to the influence of gravity or the like. Therefore, it is necessary to install the head unit 12 so that the inclination is not more than a predetermined angle. For example, the head unit 12 is installed so that the inclination angle of the nozzle surface with respect to the horizontal plane is 30 ° or less, more preferably 5 ° or less. Further, along with the limitation of the installation angle, the support rollers are arranged so that the inclination angle of the conveyance path of the low-extension continuous sheet 9A is 30 ° or less, more preferably 5 ° or less.

  In this way, by conveying the low-extension continuous sheet 9A in an arch shape in the printing section, it is possible to print an image with good image quality by making it difficult to shift the landing positions of the ink droplets. In particular, in the present embodiment, a printing surface is formed on the upper side in the thickness direction of the low-extension continuous sheet 9A, and a large amount of undried ink is attached to the surface of the printing surface, so that it is conveyed to the printing surface side. It is difficult to install rollers and support rollers. However, by transporting the low-extension continuous sheet 9A while supporting it in an arch shape from the lower side in the thickness direction, a stable transport operation can be realized without bringing a support roller or the like into contact with the printing surface side. .

<How to set the transfer position>
Here, a method for accurately setting the position in the CD direction when the low-extension continuous sheet 9A is conveyed in the printing section of the production line LM, that is, the conveyance position of the low-extension continuous sheet 9A will be described. In the printing section, an image is printed by ejecting ink droplets onto the low-stretch continuous sheet 9A that is transported. Therefore, before starting printing, the transport position of the low-stretch continuous sheet 9A and the ink droplets are changed. It is necessary to adjust the positional relationship with the nozzle surface of the printing unit 10 to be ejected to make it difficult for ink droplets to land.

  The transfer position is set with reference to the end plate DR. The end plate DR is a flat wall plate that stands upright in a direction perpendicular to the horizontal plane (vertical direction), and is provided parallel to the paper surface in FIG. Each device such as the printing unit 10 and the transport mechanism CV is fixed to a predetermined position on the production line LM by being attached to the end plate DR.

  10A to 10C are diagrams for describing a method of setting the transport position in the production line LM. When setting the transport position, first, a virtual center line is set at a position separated from the surface of the end plate DR by a predetermined distance h (see FIG. 10A). That is, the virtual center line is a straight line set on a plane parallel to the end plate DR. Next, the first transport roller CVp1 and the second transport roller CVp2 are attached to the end plate DR so that the center positions of the first transport roller CVp1 and the second transport roller CVp2 in the CD direction (rotational axis direction) overlap with the virtual center line ( (See FIG. 10B). For example, when the CD direction length of the first transport roller CVp1 and the second transport roller CVp2 is 2L1, each transport roller is attached so that the distance between the center position and the surface of the end plate DR is h. As a result, the center position in the CD direction when the low-extension continuous sheet 9A is conveyed coincides with the virtual center line. Next, for the plurality of heads 121 provided in the head unit 12, the printing unit 10 is attached to the end plate DR so that the center position of the nozzle row in the CD direction overlaps the virtual center line (see FIG. 10C). For example, if the CD direction length of the head 121 is 2L2, each head 121 is attached so that the distance between the center position and the surface of the end plate DR is h. As a result, the center position in the CD direction during printing coincides with the virtual center line. As a result, the center in the CD direction when the low-stretch continuous sheet 9A is transported coincides with the center in the CD direction at the time of printing. Can be set. By setting the transport position in this way, ink droplets can be landed at an accurate position on the low-extension continuous sheet 9A transported in the transport direction.

  However, even after such adjustment is performed, the low-extension continuous sheet 9A may be skewed with respect to the conveyance direction while the printing operation is repeated. That is, there is a case where an inclination (displacement) occurs in the horizontal plane between the direction in which the low stretchable continuous sheet 9A is actually conveyed and the direction of the virtual center line. When such skewing occurs, a deviation occurs in the landing positions of ink droplets between the upstream side and the downstream side in the transport direction (particularly, the deviation in the CD direction becomes large), and the image quality of the printed image is deteriorated.

  Therefore, the production line LM periodically performs adjustment work for correcting skew. 11 and 12 are diagrams for explaining a method of adjusting the skew of the low-extension continuous sheet 9A in the printing section. FIG. 11A shows a case where the low-extension continuous sheet 9A is skewed toward the end plate DR in the CD direction, that is, the low-extension continuous sheet 9A is skewed to the left in the horizontal plane. In this case, as shown in FIG. 11B, the inclination of the rotation axis in the horizontal plane of the first transport roller CVp1 is changed to the direction opposite to the skew direction. That is, the rotation axis is tilted to the right in the horizontal plane. Thereby, the force which inclines and conveys the low extension continuous sheet 9A to the right side in a horizontal surface acts, and skew is corrected. Similarly, the skew can be corrected by changing the inclination of the rotation axis in the horizontal plane of the second transport roller CVp2 to a direction opposite to the skew direction.

  On the other hand, FIG. 12A shows a state in which the low-extension continuous sheet 9A is skewed to the side opposite to the end plate DR in the CD direction, that is, the low-extension continuous sheet 9A is skewed to the right side on the horizontal plane. Show. In this case, as shown in FIG. 12B, the inclination of the rotation axis in the horizontal plane of the first transport roller CVp1 is changed to the direction opposite to the skew direction. That is, in contrast to the case of FIG. 11B, the skew can be corrected by tilting the rotation axis to the left in the horizontal plane. Similarly, the skew can be corrected even if the inclination of the rotation axis in the horizontal plane of the second transport roller CVp2 is changed in the skew direction.

  13A and 13B are diagrams specifically illustrating a method of changing the inclination of the rotation axis in the horizontal plane of the first transport roller CVp1. FIG. 13A is a plan view of the first transport roller CVp1 as viewed from the downstream side toward the upstream side along the MD direction. FIG. 13B is a plan view in a horizontal plane when the first transport roller CVp1 is viewed from the vertically upper side. As shown in FIG. 13A, the first transport roller CVp1 is attached to the end plate DR by the support tool 21 and the attachment tool 22. The support tool 21 is a member that rotatably supports the rotation shaft of the first transport roller CVp1. The attachment tool 22 includes a flat plate-like attachment portion 221 and a support portion 222 provided orthogonal to the attachment portion 221, and is attached to the end plate DR by the attachment portion 221. And the upper surface part of the support tool 21 and the support part 222 of the attachment tool 22 are connected via the joint shaft 23. As shown in FIG. 13B, the joint shaft 23 is disposed at the center position in the MD direction of the first transport roller CVp1 and at the center position in the CD direction (position overlapping the virtual center line), and the joint shaft 23 is used as a fulcrum. The support 21 is rotatable with respect to the fixture 22 in a horizontal plane.

  When changing the tilt of the rotation axis in the horizontal plane of the first transport roller CVp1, the support 21 supporting the first transport roller CVp1 is tilted with respect to the mounting tool 22 using the joint shaft 23 as a fulcrum. Rotate in the direction to be changed (see FIG. 13B). Thereby, 1st conveyance roller CVp1 becomes rotatable in a horizontal surface by using the center position of MD direction and CD direction as a fulcrum. Note that the support tool 21 and the attachment tool 22 are connected so that they do not move (do not rotate) with each other at normal times. Therefore, when changing the inclination of the rotation axis of the first transport roller CVp1, a dedicated adjustment is performed. Instruments are used.

  The method of attaching the second transport roller CVp2 to the end plate DR and the method of changing the inclination of the rotation axis in the horizontal plane of the second transport roller CVp2 are performed in the same manner as the method described in FIGS. 13A and 13B.

  As shown in FIG. 4, in the production line LM of the present embodiment, a device that performs a predetermined process on the low-stretch continuous sheet 9 </ b> A, such as a drying unit 30, on the downstream side in the MD direction of the printing unit 10. Is provided. Therefore, when adjusting the skew of the low-extension continuous sheet 9A, it is desirable to change the inclination of the rotation axis in the horizontal plane for the first transport roller CVp1 instead of the second transport roller CVp2. Since the drying unit 30 is immediately disposed on the downstream side in the MD direction of the second transport roller CVp2, the skew in the upstream side in the MD direction (printing section) is inclined by tilting the rotation axis of the second transport roller CVp2 in the horizontal plane. Even if it can be adjusted, the conveyance of the low-extension continuous sheet 9A may be affected on the downstream side in the MD direction. On the other hand, if the skew of the low-extension continuous sheet 9A is adjusted by the first transport roller CVp1, skew is less likely to occur in the printing section on the downstream side in the MD direction. This is because it is easy to suppress the occurrence of skew even on the downstream side in the MD direction of the transport roller CVp2.

  Further, in the production line LM of the present embodiment, the outer diameter D2 of the second transport roller CVp2 is larger than the outer diameter D1 of the first transport roller CVp1 (see FIGS. 4 and 8). Therefore, the length wound around the outer peripheral portion of the second transport roller CVp2 is likely to be longer than the length where the low-extension continuous sheet 9A is wound around the outer peripheral portion of the first transport roller CVp1. As a result, a greater frictional force acts on the low-extension continuous sheet 9A on the second conveyance roller CVp2 side than the first conveyance roller CVp1. The greater the frictional force, the easier it is to efficiently convey the rotational force of the conveying roller to the low-extension continuous sheet 9A, and the second conveying roller CVp2 makes it easier to convey the low-extension continuous sheet 9A more stably. As described above, equipment such as the drying unit 30 is provided on the downstream side in the MD direction of the second transport roller CVp2, but the low-stretch continuous sheet 9A can be stably transported by the second transport roller CVp2. As a result, it becomes easy to carry out the drying process stably.

=== 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.

  In the above-described embodiment, a so-called line printer type in which a head unit is fixed is used as an inkjet printing apparatus. However, a serial type inkjet in which a head having a plurality of nozzles arranged in the MD direction reciprocates in the CD direction. A printing device may be used.

  In the above-described embodiment, the low-extension continuous sheet 9A is a printing medium. However, the printing medium is not limited to this, and inkjet printing is performed on a printing medium (for example, a woven cloth) other than a nonwoven fabric. It may be done. Moreover, although the sheet | seat (low-extension continuous sheet 9A) which comprises the underpants type diaper 1 was a to-be-printed medium, with respect to the sheet | seat which comprises other absorbent articles (for example, sanitary napkins, an incontinence pad, etc.) Ink jet printing may be performed.

In the production line LM described in the above-described embodiment, a step of heating the low-extension continuous sheet 9A may be provided before printing on the low-extension continuous sheet 9A by the printing unit 10.
That is, a heating unit that heats the low extensibility continuous sheet 9 </ b> A may be provided on the upstream side in the MD direction of the printing unit 10. By heating the low-extension continuous sheet 9A before printing, the gaps between the fibers of the low-extension continuous sheet 9A are expanded, and ink droplets that land on the surface of the low-extension continuous sheet 9A pass through the gaps. It becomes easy and it becomes easy to osmose | permeate the inside of the low extension continuous sheet 9A. Thereby, since it becomes difficult for ink to remain on the surface of the low-extension continuous sheet 9A, the friction resistance of the image G can be improved. Further, since the gaps are widened, the heated air can easily flow through the thickness direction of the low-extension continuous sheet 9A in the drying step after printing, and the drying of the ink can be promoted. For example, it is possible to efficiently heat the low extensibility continuous sheet 9A by providing a heater on a conveyance roller or the like constituting the conveyance mechanism CV on the upstream side in the conveyance direction of the printing unit 10. At that time, the temperature of the low-extension continuous sheet 9A can be made uniform by heating the back side and the front side of the low-extension continuous sheet 9A.

  Furthermore, heating before printing may be performed stepwise. In other words, a preheating step may be provided as a pre-stage of the pre-printing heating step. By performing stepwise heating, a rapid temperature change of the low-extension continuous sheet 9A can be suppressed.

  A cooling unit that cools the low-extension continuous sheet 9 </ b> A may be provided on the downstream side in the MD direction of the drying step 30 and on the upstream side in the MD direction of the sheet member joint 50. Since the low-extension continuous sheet 9A is heated by being blown with dry air in the drying step 30, the low-extension continuous sheet 9A may be stretched due to a tension during conveyance, or the like, or the sheet member joining portion 50 When joining with the stretchable continuous sheet 8A, the elastomer component of the stretchable continuous sheet 8A may be destroyed. Then, it becomes easy to manufacture a higher quality sheet member (exterior continuous sheet 7A) by lowering the temperature of the low extensibility continuous sheet 9A to near normal temperature by the cooling unit.

1 disposable diapers (absorbent articles, diapers),
3 Absorbent body, 3c Absorbent core,
4 Top sheet,
5 Leak-proof sheet,
7 exterior sheet, 7A exterior continuous sheet,
7f ventral side, 7b dorsal side, 7c crotch, 7eW end,
8 inner layer sheet (elastic sheet), 8A elastic continuous sheet,
9 outer layer sheet (low extensibility sheet), 9A low extensibility continuous sheet,
10 Printing section (ink ejection device),
12 head units, 121 heads, 121s short head,
13 Print control unit,
21 Supporting tool, 22 Mounting tool, 221 Mounting part, 222 Supporting part,
23 Joint shaft,
30 Drying section,
31 Drying chamber, 32 Conveyor belt, 33 Air outlet, 34 Pressure chamber,
40 Cleaning mechanism,
41 Wiping unit, 42 moving unit,
50 sheet member joint,
51 anvil roller, 52 ultrasonic horn,
LM production line,
CV transport mechanism (transport part),
CVp1 first transport roller,
CVp2 second transport roller,
Sr1 first support roller,
Sr2 second support roller,
Sr3 third support roller,
Sr4 to Sr6 support rollers,
S1-S5 Support point Nz Nozzle DR End plate

Claims (10)

An apparatus for manufacturing a composite sheet according to an absorbent article,
The composite sheet is less stretchable than the stretchable sheet, which forms an inner layer facing the wearer's skin when wearing the absorbent article, and an outer layer facing the non-skin side when worn. Having a sheet member as a low stretch sheet,
The manufacturing apparatus includes :
An end plate made of a plate material standing upright in a direction perpendicular to the horizontal plane;
A first conveyance roller that conveys the sheet member in a conveyance direction while supporting the sheet member; a second conveyance roller that is provided downstream of the first conveyance roller in the conveyance direction; and the first conveyance roller And a support roller provided between the second transport roller and supporting the sheet member, and a transport unit,
A printing unit that prints an image by ejecting ink droplets onto the sheet member from an ink ejection device disposed between the first transport roller and the second transport roller;
A drying section provided on the downstream side in the transport direction of the second transport roller;
A sheet member joining portion that is provided on the downstream side in the transport direction of the drying unit, and that joins the stretchable sheet to a surface opposite to the printing surface of the sheet member;
With
The position where the support roller supports the sheet member is higher than the position where the first transport roller supports the sheet member, and the position where the second transport roller supports the sheet member. The position where the support roller supports the sheet member is higher,
The center position in the orthogonal direction perpendicular to the transport direction of the nozzle row provided in the printing unit overlaps the virtual center line set at a position away from the surface of the end plate by a predetermined distance,
For at least one of the first transport roller and the second transport roller, the skew of the sheet member is adjusted by changing the inclination of the rotation axis in the horizontal plane,
The drying section, the composite sheet wherein while the printing surface of the sheet member is passed through a drying chamber while sucking and holding the side opposite, blowing air toward the printing surface of the sheet member, it is characterized by Manufacturing equipment. The composite sheet manufacturing apparatus according to claim 1,
The transport unit includes a first support roller, a second support roller, and a third support roller arranged along the transport direction,
The position where the second support roller supports the sheet member is higher than the position where the first support roller supports the sheet member, and the third support roller supports the sheet member. The apparatus for producing a composite sheet , wherein a position where the second support roller supports the sheet member is higher than a position. An apparatus for producing a composite sheet according to claim 1 or 2,
The printing unit has a plurality of head units that discharge the ink droplets from nozzles along the transport direction,
The support roller is provided at a position between two different head units adjacent to each other in the transport direction,
The apparatus for producing a composite sheet , wherein the sheet member is supported by being spanned between the plurality of support rollers. An apparatus for producing a composite sheet according to claim 3,
The sheet member is conveyed while being supported so as to have an inclination of a predetermined angle with respect to a horizontal plane in at least a partial region between the first conveyance roller and the second conveyance roller,
The head unit is arranged such that a plurality of the nozzles are arranged on the same plane and the nozzle surface is inclined according to the inclination so that the nozzle surface and the sheet member are parallel to each other. Manufacturing equipment for composite sheets . A manufacturing apparatus for a composite sheet according to any one of claims 1 to 4,
The said support roller is arrange | positioned in the position which does not oppose the nozzle row provided in the said printing part, The manufacturing apparatus of the composite sheet characterized by the above-mentioned. An apparatus for producing a composite sheet according to claim 5,
The said support roller receives the motive power from a power source, and is rotationally driven, The composite sheet manufacturing apparatus characterized by the above-mentioned. An apparatus for producing a composite sheet according to claim 5 or 6,
An apparatus for manufacturing a composite sheet , comprising: a cleaning mechanism that removes ink adhering to the outer peripheral surface in contact with the outer peripheral surface of the support roller. The composite sheet manufacturing apparatus according to any one of claims 1 to 7,
An apparatus that performs a predetermined process on the sheet member is provided on the downstream side in the transport direction of the second transport roller,
The composite sheet manufacturing apparatus, wherein the skew of the sheet member is adjusted by changing an inclination of a rotation axis in a horizontal plane with respect to the first transport roller. It is a manufacturing apparatus of the composite sheet according to claim 8,
In the transport unit, than the length of the sheet member is wound around the first conveying roller, towards the length of the sheet member is wound around the second conveying roller is long, it is characterized by complex Sheet manufacturing equipment. A method for producing a composite sheet according to an absorbent article,
The composite sheet is less stretchable than the stretchable sheet, which forms an inner layer facing the wearer's skin when wearing the absorbent article, and an outer layer facing the non-skin side when worn. Having a sheet member as a low stretch sheet,
The manufacturing method includes :
Transporting in the transport direction while supporting the sheet member related to the absorbent article by the first transport roller and the second transport roller provided on the downstream side in the transport direction from the first transport roller;
Supporting the sheet member by a support roller provided between the first transport roller and the second transport roller;
Printing an image by ejecting ink droplets onto the sheet member from an ink ejection device disposed between the first transport roller and the second transport roller;
Drying the sheet member using a drying unit on the downstream side in the transport direction of the second transport roller;
Bonding the stretchable sheet to a surface opposite to the printing surface of the sheet member on the downstream side in the transport direction of the drying unit;
Have
The position where the support roller supports the sheet member is higher than the position where the first transport roller supports the sheet member, and the position where the second transport roller supports the sheet member. The position where the support roller supports the sheet member is higher,
The skew of the sheet member is adjusted by changing the inclination of the rotation axis in the horizontal plane for at least one of the first transport roller and the second transport roller ,
The drying section, the composite sheet wherein while the printing surface of the sheet member is passed through a drying chamber while sucking and holding the side opposite, blowing air toward the printing surface of the sheet member, it is characterized by Manufacturing method.

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