JP6184016B2 - Disposable diapers - Google Patents

Description

  The present invention relates to a disposable diaper.

  Disposable diapers generally have a waist flap portion composed of a plurality of sheets extending in the front-rear direction from front and rear edges of the absorbent body. At the edge of the waist flap, that is, at the edge of the diaper, a plurality of sheets may be brought into a non-joined state or a joined state. For example, Patent Document 1 describes that a waistline member including a waist flap is composed of two webs and an elastic member sandwiched between the two webs in an expanded state. However, when a plurality of sheets are in a non-joined state at the end portion of the waist flap, the mouth opening state occurs, and as a result, the elastic member disposed between the sheets is separated from the sheets. There is a fear. In addition, the appearance may not give a good impression. Therefore, processing is often performed so that this mouth opening does not occur. For example, it is known to perform a process of extending the outermost sheet of the plurality of sheets outward from the edge and folding the extended portion back to the topsheet. In that case, the number of sheets stacked on the edge increases, and good air permeability may be difficult to obtain.

  As a method for preventing mouth opening at the end of the waist flap without folding the sheet, Patent Document 1 describes that the edge of the waist belt including the waist flap is joined by a heat seal, a sonic seal, or an adhesive. Has been. Moreover, in patent document 2, between the edge of a waist area and the waist elastic body distribute | arranged to the position spaced apart from this edge, the inner / outer surface sheet | seat which comprises this waist area is joined by heat-pressing. The formation of a seal portion is described.

  Moreover, although it is not a position of a waist flap, as a method of joining the several sheet | seat which comprises a diaper, in patent document 4, the method of forming the side seal part of a pants-type diaper by fusing by irradiation of a laser beam. Proposed.

JP 2007-185211 A JP 2009-233161 A JP 2012-75612 A JP 2010-188629 A

  However, in the means for folding back the sheet described in Patent Document 1, the number of sheets constituting the waist flap increases, and the air permeability of the waist flap may decrease due to this. In addition, when the diaper is attached / detached, a finger may be caught on a portion where the sheet is folded, and the sheet may be unintentionally peeled off. In the techniques described in Patent Documents 2 and 3, the edge of the waist flap may be formed hard due to heat sealing or adhesion by an adhesive, and the texture of the waist flap may be reduced. Moreover, when the waist part elastic member is arrange | positioned at a waist flap, it originates in the edge formed hard, and the elastic response of a waist part elastic member may fall.

  Therefore, the subject of this invention is providing the disposable diaper which can eliminate the fault which the prior art mentioned above has.

The present invention has a longitudinal direction and a width direction orthogonal to the longitudinal direction, and is provided with a ventral side portion located on the abdomen side of the wearer when worn on one side of the longitudinal direction, and worn on the other side of the longitudinal direction. In disposable diapers comprising a dorsal part located on the dorsal side of the person,
The longitudinal direction end region in the ventral side portion or the dorsal side portion is composed of a laminated structure of a plurality of sheets, and the edge extending in the width direction in the end portion region is fused with the plurality of sheets. Consisting of the fused part
The present invention provides a disposable diaper in which the thickness of the fused part is smaller than the sum of the individual thicknesses of the plurality of sheets constituting the fused part.

  ADVANTAGE OF THE INVENTION According to this invention, the disposable diaper which exhibits a favorable texture, does not produce an opening | mouth at an edge, has a favorable stretch response, and has a waist part with high air permeability is provided.

FIG. 1 is a perspective view schematically showing a pants-type disposable diaper which is an embodiment of the disposable diaper of the present invention. FIG. 2 is a cross-sectional view schematically showing a cross section taken along line II of FIG. FIG. 3 is a plan view schematically showing an unfolded and extended state of the diaper shown in FIG. FIG. 4 is a cross-sectional view along the longitudinal direction in the end region of the abdominal side and the back side of the diaper shown in FIG. FIG. 5 is a perspective view schematically showing a manufacturing process of a strip-shaped exterior body in manufacturing the diaper shown in FIG. FIG. 6 is a perspective view schematically showing a process of manufacturing a fusion part at an edge using a laser-type bonding apparatus in the manufacture of the diaper shown in FIG. FIGS. 7 (a) to 7 (c) each illustrate a state in which an edge composed of a fused portion is formed at the same time as the strip-shaped exterior body is divided using the laser type bonding apparatus shown in FIG. It is explanatory drawing. FIG. 8 is a perspective view schematically showing a process of manufacturing a pants-type disposable diaper using a strip-shaped exterior body obtained using the laser-type bonding apparatus shown in FIG. FIG. 9 is an exploded perspective view showing an exterior body of a pants-type disposable diaper as another embodiment of the disposable diaper of the present invention.

  The present invention will be described below based on preferred embodiments with reference to the drawings. The pants-type disposable diaper 1 which is one embodiment of the disposable diaper of the present invention includes an absorbent main body 2 and an exterior body 3 that forms the outer surface of the diaper, as shown in FIGS. Left and right side edges A1, A1 along the longitudinal direction X of the exterior body 3 in the (abdominal side 1A) and left and right side edges B1, B1 along the longitudinal direction X of the exterior body 3 in the back body R (back side 1B) Is a pants-type disposable diaper in which a pair of side seal portions 4, 4, a waist opening 8, and a pair of leg openings 9, 9 are formed. The exterior body 3 is positioned on the non-skin contact surface side of the absorbent main body 2 and fixes the absorbent main body 2.

  The diaper 1 has the longitudinal direction X equivalent to a wearer's front-back direction and the width direction Y orthogonal to this in the planar view of the expansion | deployment and expansion | extension state as shown in FIG. The diaper 1 can be divided into a crotch part 1C disposed in the crotch part at the time of wearing, and an abdominal side part 1A and a back side part 1B located in the longitudinal direction X. The abdominal side portion 1 </ b> A is located on the abdomen side of the wearer when the diaper 1 is worn, and is disposed on one side in the longitudinal direction X of the diaper 1. The back side portion 1 </ b> B is located on the back side of the wearer when the diaper 1 is worn, and is disposed on the other side in the longitudinal direction X. The exterior body 3 in the crotch part 1 </ b> C has recesses for forming leg openings 9, 9 at the left and right side edges along the longitudinal direction X. Further, as shown in FIG. 3, the diaper 1 can be divided into a front body F and a back body R with a virtual center line CL that bisects the diaper 1 in the longitudinal direction X as a boundary.

  In the present specification, the skin contact surface is a surface of the diaper 1 or a component thereof (for example, an absorbent main body) that is directed toward the wearer's skin when worn, and the non-skin contact surface is the diaper 1 or its It is a surface which is directed to the opposite side (clothing side) of the skin side of the wearer during wearing. In the diaper 1, the longitudinal direction X coincides with the direction (longitudinal direction) along the long side of the absorbent main body 2 that is the diaper 1 or its constituent member, and the width direction Y is the absorbent that is the diaper 1 or its constituent member. It coincides with the width direction of the main body 2.

  As shown in FIG. 3, the absorbent main body 2 has a vertically long shape in which one direction (longitudinal direction X) is relatively long, and a surface sheet 2 a that forms a skin contact surface, and a non-skin contact A back sheet 2b that forms a surface, and a liquid-retaining absorbent 2c that is interposed between the two sheets are provided. The absorber 2c has a shape that is long in the same direction as the longitudinal direction X. The absorbent main body 2 is joined to the central portion of the outer package 3 by a known joining means (adhesive or the like) so that the longitudinal direction thereof coincides with the longitudinal direction X of the diaper 1 in the unfolded and extended state. Here, the expanded and extended state means that the side seal part is peeled off, the diaper is set in the expanded state, the elastic member of each part is expanded, and the design dimensions (the influence of the elastic member is completely eliminated). In this state, it is the same as the size when it is spread in a flat shape.

  As shown in FIGS. 2 and 3, the outer package 3 is disposed on the outer layer sheet 31 that forms the outer surface of the diaper 1 (the non-skin contact surface of the outer package 3), and the inner surface side of the outer layer sheet 31. 1 and an inner layer sheet 32 that forms the inner surface (skin contact surface of the exterior body 3). Between the both sheets 31 and 32, a plurality of thread-like or belt-like waist elastic members 5 fixed by an adhesive are disposed in an expanded state. The waist elastic member 5 extends in the width direction Y. The waist elastic member 5 is disposed in the end regions 1Ae and 1Be in the longitudinal direction X in the ventral side portion 1A and the back side portion 1B. Accordingly, the end regions 1Ae and 1Be of the abdominal side portion 1A and the back side portion 1B can be expanded and contracted along the width direction Y, and a waist gather is formed. The end regions 1Ae and 1Be include end edges 1At and 1Bt, and include a region from the end edges 1At and 1Bt to a predetermined distance inward in the longitudinal direction Y. For example, the region between the end edges 1At and 1Bt of the ventral side portion 1A and the back side portion 1B and the front and rear end edges of the absorbent main body 2 is included in the end portion areas 1Ae and 1Be.

  Between the outer layer sheet sheet 31 and the inner layer sheet 32, a plurality of thread-like or belt-like leg elastic members 7 fixed by an adhesive are arranged in an extended state. The leg elastic member 7 extends along the shape of the recessed portion on both side edges in the width direction Y in the central region in the longitudinal direction X of the exterior body 3. Further, between the waist elastic member 5 and the leg elastic member 7, a plurality of thread-like or band-like waist elastic members 6 fixed by an adhesive are stretched between the sheets 31 and 32. Is arranged in. The trunk periphery elastic member 6 extends in the width direction Y. By arranging the leg elastic member 7 and the waistline elastic member 6, a leg gather and a waistline gather are formed in the diaper 1.

  The exterior body 3 (the outer layer sheet 31 and the inner layer sheet 32) includes a resin material and is formed using the resin material as a main component. As an example of the outer package 3 (the outer layer sheet 31 and the inner layer sheet 32), the resin material includes a heat-sealable synthetic resin such as polyethylene, polyethylene terephthalate, and polypropylene, and includes a nonwoven fabric, a film, a laminate sheet of a nonwoven fabric and a film, and the like. The thing which becomes. Examples of the nonwoven fabric include air-through nonwoven fabric, heat roll nonwoven fabric, spunlace nonwoven fabric, spunbond nonwoven fabric, and melt blown nonwoven fabric.

  As shown in FIGS. 1 and 2, the pair of side seal portions 4, 4 in the diaper 1 is formed continuously over the entire length between the waist opening 8 and the leg opening 9. The side seal portions 4 and 4 are formed by melting and solidifying constituent resins of the sheets in a state where the edges of the plurality of sheets (the outer layer sheet 31 and the inner layer sheet 32) constituting the exterior body 3 overlap. Yes. Alternatively, it is formed by bonding with an adhesive.

  End regions 1Ae and 1Be of the ventral side portion 1A and the back side portion 1B of the diaper 1 are configured by a laminated structure of two sheets, an outer layer sheet 31 and an inner layer sheet 32. In the end regions 1Ae and 1Be, the end edges 1At and 1Bt extending along the width direction Y are formed of a fused portion 40 formed by fusing these two sheets as shown in FIG. The fused part 40 continuously extends linearly along the width direction Y of the diaper 1 and forms the edge of the waist opening 8. The fused part 40 is formed from one side seal part 4 formed on the diaper 1 to the other side seal part 4. The fused portion 40 is substantially free of intermittent portions. The fused portion 40 is formed by melting and solidifying constituent resins of a plurality of sheets (the outer layer sheet 31 and the inner layer sheet 32) constituting the end regions 1Ae and 1Be in a state where the edge portions thereof overlap each other. ing. Therefore, the fusion | melting part 40 is a resin of the sheet | seat which comprises this in the bulk state. The bulk state is a state in which the constituent fibers of the nonwoven fabric, which is a sheet constituting the fused portion 40, loses the fiber state due to melting, and becomes a block resin.

  In the following description, as shown in FIG. 4, in the fused portion 40 constituting the edges 1 At and 1 Bt, the length along the longitudinal direction X in the direction in which the edges 1 At and 1 Bt extend, that is, in the cross section orthogonal to the width direction Y. The thickness is defined as the width W, and the length along the transverse direction Z, which is the thickness direction of the outer package 3, is defined as the thickness T in FIG. The thickness direction of the fused part 40 is the same as the thickness direction of the sheet constituting the fused part 40. The thickness T of the fused part 40 is smaller than the sum of the individual thicknesses of the sheets constituting the fused part 40, that is, the sum of the thicknesses of the outer layer sheet 31 and the inner layer sheet 32. That is, when the thickness of the outer layer sheet 31 is Ta and the thickness of the inner layer sheet 32 is Tb, the relationship of T <Ta + Tb is established. Since the thickness T of the fused part 40 and the thickness of the sheet constituting the fused part 40 are in such a relationship, the outer layer sheet 31 and the inner layer sheet 32 are sealed so as not to open. In addition to being able to do this, protrusions do not appear on the skin side and non-skin surface side, and the touch is suppressed from becoming worse. Further, when the abdominal side portion 1A and / or the back side portion 1B is expanded and contracted along the width direction Y, the fused portion 40 can be deformed in response to the expansion and contraction. In other words, the end edges 1At, 1Bt quickly follow the expansion / contraction of the waist elastic member 5, and the expansion / contraction response of the end edges 1At, 1Bt is improved. Further, since no adhesive is used to form the edges 1At and 1Bt, the air permeability in the vicinity of the edges 1At and 1Bt is not easily lost. In FIG. 4, the thickness T of the fused portion 40 is drawn to be the same as the sum of the thickness Ta of the outer layer sheet 31 and the thickness Tb of the inner layer sheet 32, but this is for convenience. As described above, T <Ta + Tb.

  From the viewpoint of making the above advantageous effects even more prominent, when the total thickness of the sheets constituting the fused portion 40 is Tt (Tt = Ta + Tb), the fusion portion 40 has a total thickness Tt. The value of T / Tt, which is the ratio of the thickness T, is preferably 0.9 or less, particularly preferably 0.8 or less. The value of T / Tt is preferably 0.05 or more, particularly 0.1 or more. For example, the value of T / Tt is preferably 0.05 or more and 0.9 or less, and more preferably 0.1 or more and 0.8 or less.

  From the same viewpoint, the thickness T of the fused part 40 is preferably larger than the thickness of each sheet itself constituting the fused part 40. For example, the thickness T of the fused part 40 is preferably larger than the thickness Ta of the outer layer sheet 31. In addition, the thickness T of the fused part 40 is preferably larger than the thickness Tb of the inner layer sheet 32. The thickness T of the fused part 40 is particularly preferably larger than any of the individual sheets constituting the fused part 40, but is not limited to this, among the individual sheets constituting the fused part 40. It is sufficient that it is larger than the thickness of any one of the sheets.

  In the present invention, the thickness T of the fused portion 40 is determined by cutting out a cross section as shown in FIG. 4 from the outer body 3 on the front body 1A side and the outer body 3 on the back body 1B side, and the cut cross section is a microscope (Keyence Corporation). It is measured by observing with VHX-1000). The cutting is performed using, for example, a razor. Prior to cutting, the fusion bonding part 40 is cooled by cold spray. The magnification is 50 to 200 times. Then, the thickness T is measured from the observation image. The width W described later is also measured by the same method.

On the other hand, the thicknesses Ta and Tb of the sheets constituting the fused part 40 are measured as follows. The measurement position is a position 1 mm to 11 mm away from the fused part 40 in the longitudinal direction X. At this position, a sample is cut out from each of the outer body 3 on the front body 1A side and the outer body 3 on the rear body 1B side. This sample is sandwiched between flat plates and a load of 0.5 cN / cm ² is applied. The distance between the flat plates in this state is measured, and the value is taken as the thickness. The sample is cut into a 10 mm × 10 mm square. If the dimensions cannot be cut out, cut them out as close as possible. When the sheets are joined with an adhesive, the adhesive is dissolved using a solvent to separate the sheets.

  The thickness T of the fused part 40 and the thickness of each sheet constituting the fused part 40 are measured for three different cross sections in the direction along the edges 1At and 1Bt. Each value is an average value of. The measurement is preferably performed up to a unit of 0.01 mm.

  The relationship between the thickness T of the fused part 40 and the thickness of the sheet constituting the same is as described above, and the value of the thickness T itself of the fused part 40 is 0.05 mm or more, particularly 0.1 mm or more. It is preferably 5 mm or less, particularly 3 mm or less. For example, the thickness T of the fused part 40 is preferably 0.05 mm or more and 5 mm or less, and more preferably 0.1 mm or more and 3 mm or less. By setting the thickness T of the fused portion 40 to such a value, the texture of the fused portion 40 can be improved while maintaining the bonding strength of the fused portion 40 at a sufficiently high value. it can.

  From the viewpoint of enhancing the texture of the edges 1At and 1Bt formed of the fused portion 40, it is also advantageous to adjust the relationship between the thickness T and the width W of the fused portion 40. Specifically, the thickness T / width W, which is the ratio of the thickness T to the width W of the fused part 40, is preferably 1 or more, particularly 1.2 or more. The value of thickness T / width W is preferably 4 or less, particularly 3.5 or less. For example, the value of width W / thickness T is preferably 1 or more and 4 or less, particularly 1.2 or more and 3.5 or less.

  The value of the width W itself of the fused part 40 is preferably 0.05 mm or more, particularly 0.1 mm or more, preferably 1 mm or less, particularly 0.7 mm or less. For example, the width W of the fused part 40 is preferably 0.05 mm or more and 1 mm or less, and more preferably 0.1 mm or more and 0.7 mm or less.

  As shown in FIG. 4, when the fused part 40 is viewed in a longitudinal section along the thickness direction of the outer package 3, the outer edge 40 a of the fused part 40 is convex toward the inside along the longitudinal direction X of the diaper 1. It has an arc shape. The fused portion 40 has the largest thickness in the central area along the thickness direction of the exterior body 3 (lateral direction Z in FIG. 4), and the thickness gradually decreases from the central area toward the side. . The fused part 40 having such a shape has a so-called crescent or half-moon shape (the fused part 40 shown in FIG. 4 has a crescent shape). When the fusion part 40 is formed in such a crescent shape or a half moon shape, the amount of resin present at both ends in the lateral direction Z of the fusion part 40 is smaller than that in the central region. The flexibility and feel of each sheet constituting the sheet 40 are less likely to be impaired. In addition, since a sufficient amount of resin is present in the central region in the lateral direction Z of the fusion part 40, the fusion part 40 has a practically sufficient strength and is fused while the diaper 1 is worn. Inconveniences such as breakage of the portion 40 are unlikely to occur.

  As shown in FIG. 4, the width direction Y (in FIG. 4, the direction orthogonal to the paper surface) is located at a distance D inward in the longitudinal direction X from the end edges 1 At and 1 Bt in the ventral side portion 1 A and the back side portion 1 B. A plurality of waist elastic members 5 extending between the outer layer sheet 31 and the inner layer sheet 32. The waist elastic member 5 is joined to the outer layer sheet 31 and the inner layer sheet 32 by an adhesive. Therefore, the outer layer sheet 31 and the inner layer sheet 32 are fixed via the waist elastic member 5 at the portion where the waist elastic member 5 exists. In contrast, between the end edges 1At, 1B and the waist elastic member 5 (in the range indicated by reference sign D in FIG. 4), an adhesive that fixes the outer layer sheet 31 and the inner layer sheet 32 is used. Does not exist. Accordingly, the sheets 31 and 32 are not joined between the end edges 1At and 1B and the waist elastic member 5. By setting it as such a non-joining state, the texture of end part area | region 1Ae of 1A of ventral | abdominal side parts and the back side part 1B and 1Be can be made still better. In addition, the expansion and contraction of the waist elastic member 5 is hardly inhibited. In this case, the outer layer sheet 31 and the inner layer sheet 32 are not joined between the end edges 1At, 1B and the waist elastic member 5 over the entire region in the width direction Y of the abdominal part 1A and the back part 1B. Although it is most preferable, if there is a part where the outer layer sheet 31 and the inner layer sheet 32 are not joined between the end edges 1At, 1B and the waist elastic member 5, the end portion The texture of the areas 1Ae and 1Be is improved.

  From the viewpoint of further improving the texture of the end regions 1Ae and 1Be, when the end regions 1Ae and 1Be are observed in a cross-section extending in the longitudinal direction X along the thickness direction of the exterior body 3, the edge 1At, It is preferable that no sharp portion is observed at 1 Bt. This is because the sharp portion may irritate the wearer's skin. As the sharp part, for example, when a cross section of the edge 1At, 1Bt (see FIG. 4) is observed, a protrusion having a tip formed by the intersection of two sides can be mentioned. In particular, it is preferable that no projection having an acute angle between two sides is observed. Such a sharp portion is generally formed by cutting a sheet with a cutter. On the other hand, in this embodiment, since it is clear from the manufacturing method of the diaper 1 mentioned later, since the edge 1At and 1Bt are not formed by cutting | judgement of the sheet | seat with a cutter, it is difficult to form a sharp part.

  The diaper 1 mentioned above can be manufactured, for example with the manufacturing method demonstrated below. The manufacturing method of the diaper 1 includes a step of manufacturing a strip-shaped exterior body precursor 3 ′; and body fixing for mounting and fixing the absorbent body 2 on the exterior body precursor 3 ′ in a direction orthogonal to the conveying direction. A diaper continuum manufacturing process for manufacturing a diaper continuous body by irradiating laser beams to both sides along the transport direction of the outer package precursor 3 ′ to form continuous edges 1At and 1Bt; A folding step of bending the continuum in a state where the front body side and the back body side are overlapped; and a heating and pressurizing step of bringing the formation site of the side seal part in the folded diaper continuum into a pressurized state under heating; Cutting the heated and pressurized site to produce individual diapers from the diaper continuum.

  More specifically, first, as shown in FIG. 5, the belt-shaped outer layer sheet 31 continuously supplied from the raw fabric roll (not shown) and the continuous roll roll (not shown) are continuously supplied. Between the belt-shaped inner layer sheet 32, the waist elastic member 5 forming the waist gather, the waist elastic member 6 forming the waist gather, and the leg elastic member 7 forming the leg gather are stretched to a predetermined elongation rate. A plurality of each are arranged in the stretched state. At this time, the leg elastic member 7 is arranged while forming a predetermined leg-circumferential pattern via a known swing guide (not shown) that reciprocates perpendicular to the sheet flow direction. In addition, the belt-shaped outer layer sheet 31 and the belt-shaped inner layer sheet 32 are coated with an adhesive coating machine (see FIG. (Not shown) can be applied with hot-melt adhesive. The waist elastic member 5, the waistline elastic member 6, and the leg elastic member 7 may be attached to an adhesive coating machine (not shown) before these elastic members are arranged between the sheets 31 and 32. Hot melt adhesives can be applied.

  And as shown in FIG. 5, between the pair of nip rolls 11, 11, a belt-shaped outer layer sheet 31 and a belt-shaped outer layer sheet 5 in which a waist elastic member 5, a waistline elastic member 6 and a leg elastic member 7 are sandwiched in an expanded state. By feeding and pressurizing the inner layer sheet 32, a strip-shaped exterior body precursor 3 ′ in which a plurality of elastic members 5, 6, 7 are arranged in an expanded state between the strip-shaped sheets 31, 32 is formed. In the step of forming the exterior body precursor 3 ′, a plurality of joint portions that join the belt-like outer layer sheet 31 and the belt-like inner layer sheet 32 between two adjacent waistline elastic members 6 and 6 are formed as convex rolls. 12 and a corresponding joining means such as anvil roll 13 corresponding thereto. Thereafter, if necessary, a plurality of waistline elastic members 6 and a plurality of leg portion elasticities are made by using elastic member precut means (not shown) so as to correspond to positions where the absorbent main body 2 described later is disposed. The member 7 is pressed and divided into a plurality of pieces so that the contraction function is not expressed. Examples of the elastic member precut means include an elastic member dividing portion used in the method for manufacturing a composite elastic member described in JP-A-2002-253605.

  Next, as shown in FIG. 6, an adhesive such as a hot melt adhesive is applied in advance to the absorbent main body 2 manufactured in a separate process, and the absorbent main body 2 is rotated by 90 degrees to form a belt-shaped outer package. It is intermittently supplied and fixed on the inner layer sheet 32 constituting the precursor 3 ′. Subsequently, as shown in the drawing, a leg hole LO 'is formed inside the annular portion surrounded by the leg elastic member 7 in the belt-shaped exterior body 3 in which the absorbent main body 2 is disposed. This leg hole forming step can be carried out by using a technique similar to that in a conventional method for manufacturing this type of article, such as a rotary cutter and a laser cutter.

  Next, as shown in FIG. 6, the thus manufactured belt-shaped outer package 3 is irradiated with laser light using a laser bonding device 20 to form continuous edges 1At and 1Bt. Get 3. As shown in FIG. 6, the laser-type bonding apparatus 20 includes a hollow cylindrical roll 23 that is rotationally driven in the direction of arrow A, and a cylindrical shape that is disposed in a hollow portion of the cylindrical roll 23 and forms a peripheral surface portion of the cylindrical roll 23. The irradiation head 35 which irradiates the laser beam 30 toward the support member 21 and the belt type pressure device 26 including the endless pressure belt 24 (pressing member) are provided.

  The laser-type bonding apparatus 20 has an interval adjustment mechanism (not shown) that can increase or decrease the interval between the support member 21 (the peripheral surface portion of the cylindrical roll 23) and the pressure belt 24. By adjusting the interval, the support member The pressure applied to the belt-shaped exterior body 3 can be appropriately adjusted by the pressure belt 21 and the pressure belt 24.

  The support member 21 forms a peripheral surface portion (contact portion with the workpiece) of the cylindrical roll 23, and is between a pair of annular frames 22, 22 that form both ends of the cylindrical roll 23 in the rotation axis direction. It is pinched and fixed. The support member 21 is made of a metal material such as iron, aluminum, stainless steel, or copper, or a material having heat resistance such as ceramics.

  The support member 21 has a light passage portion (not shown) through which laser light can pass. The light passing portion is formed of a slit-like opening (not shown) that penetrates the support member 21 in the thickness direction. The opening has a longitudinal direction that coincides with the transport direction A of the strip-shaped exterior body precursor 3 ′, more specifically, the same direction as the rotation direction of the cylindrical roll 23. 21 is formed. The support member 21 allows the laser beam to pass through the opening, but does not allow the laser beam to pass (transmit) at portions other than the opening. As a method of forming the opening in the support member 21, the opening is formed by etching, punching, laser processing or the like at a predetermined position of the support member 21 made of a single annular member having the same length as the circumferential length of the annular frame 22. The method of drilling is mentioned.

  The belt-type pressure device 26 includes an endless pressure belt 24 (pressing member) and three rolls 25a, 25b, and 25c that rotate in a state where the pressure belt 24 is stretched. The rolls 25a, 25b, and 25c may be drive rolls or driven rolls that rotate with the cylindrical roll 23. The pressure belt 24 moves at the same speed as the cylindrical roll 23 (supporting member 21) by rotating any one or more of the rolls 25a, 25b, and 25c, or with the cylindrical roll 23. The support member 21 and the pressure belt 24 are preferably maintained in a predetermined temperature range by air cooling, water cooling, or the like.

  As the pressure belt 24 (pressing member), a heat-resistant metal or resin belt that can withstand the heat generated during processing can be used. For example, the pressure belt 24 is made of a metal material such as iron, aluminum, or stainless steel. Can be used. Further, as the pressure belt 24, a belt that does not transmit the laser beam irradiated to the belt-shaped outer package precursor 3 'that is a workpiece is usually used. However, a material having transparency can also be used.

  As shown in FIG. 6, an irradiation head 35 that irradiates a laser beam 30 toward the support member 21 that forms the peripheral surface portion of the cylindrical roll 23 is provided in the hollow portion of the hollow cylindrical roll 23. The irradiation head 35 is a galvano scanner (an apparatus having a motor shaft with a mirror) that freely scans the laser beam 30, a mechanism for moving the laser beam 30 back and forth in a direction parallel to the rotation axis of the cylindrical roll 23, and the laser beam 30. Is a mechanism for moving the position (irradiation point) of the outer body precursor 3 ′ on the support member 21 in the circumferential direction of the cylindrical roll 23, and a mechanism for making the spot diameter of the laser beam 30 constant on the circumferential surface of the cylindrical roll 23. Etc. By having such a configuration, the laser irradiation mechanism can arbitrarily move the irradiation point of the laser light 30 in both the circumferential direction of the cylindrical roll 23 and the direction orthogonal to the circumferential direction. From the viewpoint of simultaneously forming the continuous edges 1At and 1Bt, it is preferable to use two irradiation heads 35 and simultaneously irradiate the exterior body precursor 3 'with the laser light 30 from each irradiation head 35. In addition, after using one irradiation head 35 and irradiating the irradiation head with the laser beam 30 by shaking the irradiation head to either the ventral side or the back side of the exterior body precursor 3 ′, the irradiation head is applied to the other part. It is also possible to irradiate a shaking laser height 30.

  As shown in FIG. 6, the strip-shaped exterior body precursor 3 ′ forms a peripheral surface portion of a cylindrical roll 23 that is rotationally driven in the direction of arrow A in a state where a predetermined tension is applied by a guide roll (not shown). After being introduced onto the outer surface of the supporting member 21 and being conveyed around the circumferential direction by the rotation of the cylindrical roll 23 so as to be wound around the supporting member 21, the supporting member 21 is supported by an unillustrated lead roll, nip roll, etc. It leaves | separates from the member 21. In this way, the belt-shaped exterior body precursor 3 ′ is wound around the support member 21 that forms the peripheral surface portion of the cylindrical roll 23 with a predetermined tension and is transported so as to be in pressure contact with the pressure belt 24. The portion sandwiched between the support member 21 and the pressure belt 24 in the body precursor 3 ′ and the vicinity thereof are in a state of being pressurized (compressed) in the thickness direction from before being divided by the laser light irradiation. For this reason, when exterior body precursor 3 'contains a nonwoven fabric etc., this exterior body precursor 3' can be compressed more efficiently, As a result, in exterior body precursor 3 'during such compression, On the other hand, when the laser beam is irradiated and the both side portions are divided, the cut edges of the plurality of sheets (exterior body precursor 3 ′) constituting the divided portions are more reliably fused. This makes it possible to improve the fusion strength of the end edges 1At and 1Bt.

  The exterior body precursor 3 ′ is not uniform in thickness because the absorbent main body 2 is placed on the inner layer sheet 32. Therefore, the absorptive main body 2 which is a member having a large thickness may interfere with pressurization of the exterior body precursor 3 '. Therefore, from the viewpoint of effectively applying pressure to the exterior body precursor 3 ′, a concave portion into which the absorbent main body 2 is fitted is provided on the surface of the support member 21, so that the absorbent main body 2 is the exterior body precursor. You may make it not prevent pressurizing body 3 '.

  In the embodiment shown in FIG. 6, while continuously conveying the hindrance when the exterior body absorbent main body 2 pressurizes the exterior body precursor 3 ′, one surface thereof is formed with the peripheral surface portion of the cylindrical roll 23 and An exterior that is brought into contact with the outer surface of the support member 21 having a slit-like opening (not shown) through which the laser beam 30 can pass and is in a pressurized state by the support member 21 and the pressure belt 24 (pressing member). By irradiating the laser beam 30 through the opening from the support member 21 side against the hindrance when the body absorbent main body 2 pressurizes the exterior body precursor 3 ′, the exterior body absorbent main body 2 becomes the exterior body. At the same time as dividing both sides of the hindrance when the precursor 3 ′ is pressurized, the cutting edges of the plurality of sheets in the pressurized state generated by the division are fused together to form the edge 1At, 1Bt is formed. Thereby, the exterior body 3 is obtained from the exterior body precursor 3 '. The left and right side portions along the conveying direction of the exterior body precursor 3 ′ are separated from the exterior body 3 by irradiation with the laser beam 30 and discarded as trim.

  FIG. 7 is a diagram for explaining how the edges 1At and 1Bt composed of the fused portions 40 are formed at the same time as the strip-shaped outer package precursor 3 'is cut using the laser-type bonding apparatus 20. FIG. FIG. 7A schematically shows a portion 3C (scheduled portion for forming the edges 1At and 1Bt) of the strip-shaped exterior body precursor 3 'by the laser beam 30 and the vicinity thereof. The portion 3C to be divided of the exterior body precursor 3 ′ in the illustrated embodiment is located at a predetermined distance inward in the width direction from the left and right side edges along the transport direction A in the exterior body precursor 3 ′ before separation. It is. This position can be a position that is spaced 5 mm to 100 mm inward in the width direction from the left and right side edges of the outer package precursor 3 ′ before division. Such parting planned portion 3C is a two-layer structure portion in which two sheets of an outer layer sheet 31 and an inner layer sheet 32 are stacked.

  A sheet (an outer layer sheet 31 and an inner layer) constituting one surface 3a (a contact surface with the support member 21) of the exterior body precursor 3 'in the parting portion 3C having a two-layer structure in the belt-shaped exterior body precursor 3'. Any one or all of the sheets 32) absorb the laser beam 30 and generate heat. In the illustrated embodiment, all of the two sheets 31 and 32 constituting the parting portion 3 </ b> C are sheets (nonwoven fabrics) that absorb the laser beam 30 and generate heat. Further, the outer layer sheet 31 and the inner layer sheet 32 that overlap each other in the parting portion 3C and the vicinity thereof are not joined by an adhesive.

  As shown in FIG. 7B, the strip-shaped exterior body precursor 3 ′ has one surface 3a in contact with the support member 21, and a portion 3C (scheduled portion for forming the edges 1At and 1Bt) is slit-shaped. In addition to being introduced onto the support member 21 that rotates in the direction of arrow A so as to be positioned on the opening 27, the pressure belt 24 is pressed against the other surface 3b, so that the thickness is being conveyed in the direction of arrow A. Pressurized (compressed) in the direction. And the laser beam 30 is irradiated through the opening part 27 from the supporting member 21 side with respect to the parting part 3C in such a conveyance and pressurization state. As described above, the irradiation point of the laser beam 30 is configured to be arbitrarily movable within the peripheral surface of the cylindrical roll 23, and is set to move following the shape of the opening 27. The laser beam 30 is continuously radiated to the parting planned portion 3C located on the opening 27 for a certain period of time while the exterior body precursor 3 ′ is transported.

  When the laser beam 30 is irradiated to the split part 3C of the two-layer structure, the forming materials (fibers, etc.) of the sheets 31 and 32 existing in the split part 3C are vaporized by the heat generated by the direct irradiation of the laser beam 30 and disappear. The forming material existing in the vicinity of the parting portion 3C is indirectly heated by the laser beam 30 and melted. As a result, as shown in FIG. 7 (c), the scheduled splitting portion 3C of the two-layer structure is melted, and the left and right side portions along the transport direction A of the strip-shaped exterior body precursor 3 ′ are cut into a predetermined width. In this manner, at the same time that the exterior body precursor 3 ′ is divided, the cut edges of the two sheets 31 and 32 in the sheet laminate produced by the division are fused. Each of these cut edges is pressed between the support member 21 and the pressure belt 24 before the formation (before the outer body precursor 3 ′ is divided by the irradiation of the laser beam 30). Compressed state). According to the method of the illustrated embodiment, in this way, the cutting of the strip-shaped outer package precursor 3 ′ and the cutting edge of the outer package 3 in the pressurized state generated by the division by one laser light irradiation are performed as described above. There is an advantage that the diapers 1 can be efficiently manufactured because the parts can be fused simultaneously.

  By irradiating the laser beam 30 as described above, the strip-shaped exterior body 3 is manufactured from the strip-shaped exterior body precursor 3 ′, and the left and right side portions along the transport direction are trim T (see FIG. 7C). As discarded. Therefore, the width of the outer package 3 is slightly narrower than that of the outer package precursor 3 ′ before irradiation with the laser beam 30. The cut edges of the sheets 31 and 32 are heated and melted during the irradiation of the laser beam 30 and immediately after the irradiation, but the exterior body 3 and the trim T are separated by the irradiation of the laser beam 30. The outer package 3 in a state is quickly cooled and solidified by the outside air after the irradiation is completed while the pressurized state by the support member 21 and the pressure belt 24 is maintained, and the cutting edge forming material ( Fiber or the like) is fused and integrated with the melt. If necessary, the cutting edge portions of the sheets 31 and 32 may be forcibly cooled by using known cooling means such as a suction device or an exhaust device to promote the formation of the fused portion 40.

  In the above steps, the fused portion 40 is formed by irradiating the laser beam 30 from one side of the outer package precursor 3 ′, specifically, from the inner layer sheet 32 side. Therefore, in the abdominal side portion 1A and the back side portion 1B in which the fused portion 40 is formed, the surface of the inner layer sheet 32 that is the irradiation surface of the laser light 30 is the skin facing surface. By carrying out like this, the mounting | wearing feeling of the diaper 1 in a mounting state can be improved. The reason for this is as follows. When the fused portion 40 is formed by irradiating the laser beam 30 from one surface side of the exterior body precursor 3 ′, the shape of the fused portion 40 is shown in FIGS. 4 and 7C described above. It becomes as follows. However, due to the irradiation condition of the laser beam 30 and the like, in some cases, a projection due to melting and solidification of the resin may be unintentionally formed on the surface opposite to the irradiation surface of the laser beam 30. When the diaper 1 is worn so that such protrusions face the wearer's body, the protrusions may irritate the wearer's skin, which may reduce the wearing feeling. On the other hand, by making the irradiation surface of the laser beam 30 the skin-facing surface, the projections that are unintentionally directed face the outside of the diaper, so that unnecessary irritation to the wearer is not required. become.

The laser beam 30 will be described. The laser beam 30 applied to the strip-shaped exterior body precursor 3 ′ is absorbed by the sheets (the outer layer sheet 31 and the inner layer sheet 32) constituting the exterior body precursor 3 ′ to generate heat. A laser beam having a wavelength to be used is used. Here, the “sheet constituting the exterior body” is not limited to the sheet (for example, the outer layer sheet 31 in the above-described embodiment) constituting one surface of the exterior body (the contact surface with the support member 21). Any sheet may be used as long as it constitutes. Whether or not the laser light applied to the exterior body is a wavelength that is absorbed by the sheet and generates heat for the individual sheets constituting the exterior body depends on the material of the sheet and the wavelength of the laser light to be used. It depends on the relationship. When the sheet constituting the outer package is a non-woven fabric or film made of synthetic resin that is widely used in the manufacture of absorbent articles (sanitary products) such as disposable diapers and sanitary napkins, the laser beam may be CO ₂ laser, YAG It is preferable to use a laser, an LD laser (semiconductor laser), a YVO ₄ laser, a fiber laser, or the like. Moreover, when the sheet | seat which comprises an exterior body contains polyethylene, a polyethylene terephthalate, a polypropylene etc. as a synthetic resin, as a wavelength which can be absorbed by this sheet | seat and can make this sheet | seat generate | occur | produce favorably, 8.0 micrometers or more and 15. It is preferable to use 0 μm or less, and it is particularly preferable to use an oscillation wavelength of 9.0 μm or more and 11.0 μm or less of a CO ₂ laser in which a high-power laser device exists. The spot diameter of laser light, laser output, and the like can be appropriately selected in consideration of the material and thickness of the sheet constituting the exterior body.

  Next, as shown in FIG. 8, the strip-shaped exterior body 3 is folded in the width direction (a direction orthogonal to the conveyance direction of the exterior body 3). More specifically, the outer package 3 is folded in two along with the absorbent main body 2 in the width direction. In this way, the diaper continuous body 10 is obtained. The obtained diaper continuous body 10 is heat-sealed at a position where the side seal portion is to be formed, so that a heat seal portion 4 ′ is formed. The heat sealing process is performed by a heating and pressurizing process in which a portion where the side seal portion is to be formed is pressurized under heating. Next, the heat seal portion 4 ′ is cut along the longitudinal direction X of the diaper 1 at the center in the width direction, thereby forming the side seal portion 4 from the heat seal portion 4 ′ and the diaper continuous body 10. Each diaper 1 is obtained from Note that the side seal portion is not limited to being formed by heat sealing, but may be formed by other methods, for example, by irradiating a laser beam to a position where the side seal portion is to be formed.

  In the above manufacturing method, the band-shaped outer package precursor 3 ′ is divided by the irradiation of the laser beam 30, and at the same time, the fused portions 40 are formed to produce the edges 1 At and 1 Bt. The end edges 1At and 1Bt having can be manufactured by other methods. For example, the exterior body 3 having the edges 1At and 1Bt composed of the target fused portions is manufactured by pressurizing and fusing both sides of the belt-shaped exterior body precursor 3 ′ in the conveying direction A under heating. can do. Alternatively, a heat seal portion extending in the transport direction A is formed by heat sealing processing in which both side portions in the transport direction A of the belt-shaped exterior body precursor 3 ′ are pressurized under heating, and then a part of the heat seal portion May be cut along the conveying direction so that the heat seal portion has a predetermined thickness T (see FIG. 4).

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, although the said embodiment is an example which applied this invention to the underpants type disposable diaper, it replaces with this diaper and can apply this invention similarly to an unfolded type diaper.

  Moreover, although the underpants type disposable diaper 1 in the said embodiment was comprised from the single sheet | seat which the outer layer sheet 31 and the inner layer sheet | seat 32 which comprise the exterior body 3 extend from the ventral | abdominal part 1A to the back | dorsal part 1B, Instead, for example, as shown in FIG. 9, the exterior body 3 is composed of three members, an abdominal side exterior body 131, a back side exterior body 132, and a crotch part exterior body 133, and these are joined to each other. Thus, an exterior body may be formed. 9, a plurality of elastic members 136 extending in the width direction are arranged at intervals in the longitudinal direction between the two sheets 134 and 135. The abdominal side exterior body 131 and the back side exterior body 132 shown in FIG. It is in a state of being. The elastic member 136 may be fixed in the extended state or may be fixed in the non-extended state. When the elastic member 136 is fixed in the non-extended state, the elastic member 136 is sandwiched 2 The sheets 134 and 135 are preferably subjected to a stretchable process, for example, a stretch process. A method for performing such stretching is described in, for example, Japanese Patent Application Laid-Open No. 2008-179128.

  Moreover, although the edge region in the exterior body of a diaper was provided with the waist part elastic member in the said embodiment, depending on the specific use according to the wearer of the diaper, this edge region is a waist. There may be no partial elastic member.

  Further, the outer body of the diaper is disposed in the abdominal side, the back side, and the crotch part in each of the above-described embodiments, but instead of this, the exterior body is not disposed in the crotch part, The exterior body may be disposed only on the back side. In the case of this form, for example, an elastic belt having elasticity in the width direction can be used as the abdominal side portion and the back side portion.

  Furthermore, the edge which has the form mentioned above does not need to form in both an abdominal side part and a back side part, and you may form only in either an abdominal side part or a back side part.

This invention discloses the following disposable diapers further regarding embodiment mentioned above.
<1>
It has a longitudinal direction and a width direction orthogonal to the longitudinal direction, and is provided with an abdominal side portion located on the abdomen side of the wearer when worn on one side of the longitudinal direction, and on the other side of the longitudinal direction, In disposable diapers with a dorsal part located at
The longitudinal direction end region in the ventral side portion or the dorsal side portion is composed of a laminated structure of a plurality of sheets, and the edge extending in the width direction in the end portion region is fused with the plurality of sheets. Consisting of the fused part
A disposable diaper in which the thickness of the fused part is smaller than the sum of the individual thicknesses of the plurality of sheets constituting the fused part.

<2>
Both the ventral part and the dorsal part are composed of a laminated structure of a plurality of sheets,
The disposable diaper according to <1>, wherein the fusion part in the ventral part and the dorsal part is formed separately.
<3>
An elastic member extending in the width direction is disposed between the plurality of sheets at a position spaced inward in the longitudinal direction from the edge on the ventral side or the back side,
The disposable diaper according to <1> or <2>, wherein an adhesive that fixes the two sheets sandwiching the elastic member is not present between the edge and the elastic member.
<4>
The disposable diaper according to any one of <1> to <3>, wherein a sharp portion is not observed when a cross section of the edge extending in the longitudinal direction is observed along the thickness direction of the plurality of sheets.
<5>
The disposable diaper according to <4>, wherein when the cross section of the edge is observed, a projection having an acute angle between two sides is not observed.
<6>
The disposable diaper according to any one of <1> to <5>, wherein the thickness / width value, which is the ratio of the thickness to the width of the fused portion, is 1 or more.
<7>
The disposable diaper according to <6>, wherein the value of thickness T / width W, which is the ratio of the thickness to the width of the fused portion, is 1.2 or more.

<8>
The disposable diaper according to <5> or <6>, wherein the value of thickness T / width W, which is the ratio of the thickness to the width of the fused part, is 4 or less, particularly 3.5 or less.
<9>
Comprising an absorbent main body and an outer body that forms the outer surface of the diaper;
The said exterior body is what the said edge which consists of the said melt | fusion part is formed by pressurizing and fusing both sides of the conveyance direction in a strip | belt-shaped exterior body precursor under heating <1> Thru | or the disposable diaper any one of <8>.
<10>
Comprising an absorbent main body and an outer body that forms the outer surface of the diaper;
The exterior body forms a heat seal portion extending in the transport direction by heat seal processing in which both sides in the transport direction of the belt-shaped exterior body precursor are pressurized under heating, and then a part of the heat seal portion is formed. The disposable diaper according to any one of <1> to <8>, wherein the heat seal part is cut along the transport direction so as to have a predetermined thickness.
<11>
Comprising an absorbent main body and an outer body that forms the outer surface of the diaper;
The disposable diaper according to any one of <1> to <8>, wherein the exterior body is formed by irradiating a laser beam on both sides in a transport direction of a belt-shaped exterior body precursor.
<12>
The disposable diaper according to any one of <1> to <8>, wherein the fusion part is formed by irradiating a laser beam from one surface to a laminated structure of a plurality of sheets. .
<13>
The disposable diaper according to <12>, wherein the abdominal side portion or the back side portion in which the fused portion is formed has a laser light irradiation surface as a skin facing surface.
<14>
<12> or <13> in which two irradiation heads are used, and laser beams are simultaneously irradiated from the respective irradiation heads toward the edge of the front abdomen and the back side of the exterior body to form continuous edges. Disposable diapers described in 1.
<15>
Using one irradiation head, shake the irradiation head to either the front or back side of the exterior body precursor and irradiate the laser beam, then irradiate the other part with the irradiation head and irradiate the laser beam. The disposable diaper according to the above <12> or <13>, which forms a continuous edge.

<16>
The disposable diaper according to any one of <1> to <15>, wherein the fusion part has a protrusion toward a non-skin facing surface.
<17>
An elastic member extending in the width direction is disposed between the plurality of sheets in the longitudinal end region in the ventral side or the back side, whereby the ventral side or the back side is in the width direction. Can be stretched along,
Any one of <1> to <16>, wherein the fusion part is deformable in response to the expansion and contraction when the ventral part or the back part is expanded and contracted along the width direction. Disposable diapers.
<18>
Comprising an absorbent main body and an outer body that forms the outer surface of the diaper;
The disposable diaper according to any one of <1> to <17>, wherein the exterior body includes a resin material and is formed using the resin material as a main component.
<19>
Comprising an absorbent main body and an outer body that forms the outer surface of the diaper;
The left and right side edges along the longitudinal direction of the exterior body in the abdominal side and the left and right side edges along the longitudinal direction of the exterior body at the back side are joined to form a pair of side seal parts,
The disposable diaper according to any one of <1> to <18>, wherein the fusion part is formed from one side seal part formed on the diaper to the other side seal part.
<20>
The disposable diaper according to any one of <1> to <19>, wherein an intermittent portion is not substantially present in the fused portion.

<21>
When the total thickness of the sheets constituting the fused portion is Tt, the value of T / Tt, which is the ratio of the thickness T of the fused portion to the total thickness Tt, is 2 or less, particularly 1.5. The disposable diaper according to any one of the above items <1> to <20>.
<22>
The disposable diaper according to any one of <1> to <21>, wherein the value of T / Tt is 0.05 or more, particularly 0.1 or more.
<23>
The disposable according to any one of <1> to <22>, wherein the thickness of the fusion part is larger than the thickness of any one of the individual sheets constituting the fusion part. Diapers.
<24>
The disposable diaper according to any one of <1> to <13>, wherein the thickness of the fused part is larger than any of the individual sheets constituting the fused part.
<25>
The disposable diaper according to any one of <1> to <24>, wherein the fusion part has a thickness of 0.05 mm or more, particularly 0.1 mm or more.

<26>
The disposable diaper according to any one of <1> to <24>, wherein the fused portion has a thickness of 5 mm or less, particularly 3 mm or less.
<27>
The disposable diaper according to any one of <1> to <26>, wherein the width of the fused part is 0.05 mm or more, particularly 0.1 mm or more.
<28>
The disposable diaper according to any one of <1> to <27>, wherein the width of the fused part is 1 mm or less, particularly 0.7 mm or less.
<29>
<1> The outer edge of the fusion part has an arc shape protruding inward along the longitudinal direction of the diaper when the fusion part is viewed in a longitudinal section along the thickness direction of the exterior body. Thru | or the disposable diaper any one of <28>.
<30>
<1> to <29>, wherein the fusion part has the largest thickness in the central region along the thickness direction of the exterior body, and the thickness gradually decreases from the central region toward the side. The disposable diaper of any one.
<31>
The fused part is the disposable diaper according to any one of <1> to <30>, wherein a cross section along the thickness direction of the outer package is formed in a crescent shape or a half moon shape.
<32>
The disposable diaper has a pair of side seal portions, a waist opening, and a pair of legs, wherein left and right side edges along the longitudinal direction of the abdominal side and left and right side edges along the longitudinal direction of the back side are joined. A pants-type diaper in which an opening is formed,
The disposable diaper according to any one of <1> to <31>, wherein the fusion part forms an edge of the waist opening.
<33>
The disposable diaper according to <32>, wherein the fusion part is formed from one side seal part to the other side seal part.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Example 1]
A pants-type disposable diaper having the configuration shown in FIGS. 1 to 4 was manufactured by the method shown in FIGS. The outer layer sheet was composed of a stretchable nonwoven fabric made of PET (polyethylene terephthalate), PE (polyethylene), and SEPS (styrene-ethylene-propylene-styrene) resin fibers (fineness: 3.0 dtex) and a basis weight of 50 g / m ² . The inner layer sheet was composed of a spunbonded nonwoven fabric composed of PET (polyethylene terephthalate) and PE (polyethylene) resin fibers (fineness of 2.6 dtex) and a basis weight of 18 g / m ² . A CO ₂ laser was used as a laser light source. The cross-sectional shape of the fusion | melting part which comprises end edge 1At, 1Bt in the obtained diaper was as showing in FIG. The thickness T and width W of the fused part were as shown in Table 1 below. The thickness of each sheet constituting the fused part is also shown in the same table.

[Example 2]
In Example 1, instead of forming the fused part by laser light irradiation, the fused part was formed by heat seal fusing. The conditions for fusing were sealed at the same position three times with the heating setting 7, cooling setting 9, and clearance setting standard using the product name “AUTO SEALER” manufactured by FUJI IMPULSE. The thickness T and width W of the fused part were as shown in Table 1 below.

Example 3
In Example 1, it replaced with formation of the melt | fusion part by irradiation of a laser beam, the heat seal part was formed by heat sealing, and the fusion part was formed by cutting the formed heat seal part. The thickness T and width W of the fused part were as shown in Table 1 below.

[Comparative Example 1]
In this comparative example, a diaper was manufactured without forming a fused part by laser light irradiation. The edges of the ventral side portion and the back side portion of the diaper were constituted by folded portions obtained by folding the outer layer sheet and the inner layer sheet toward the absorbent main body. Therefore, the end regions of the ventral side portion and the back side portion have a laminated structure of a total of five sheets. The folded portions were joined with a hot melt adhesive.

[Comparative Example 2]
Also in this comparative example, a diaper was manufactured without forming a fused part by laser light irradiation. In this diaper, the sheets constituting the abdominal side and the back side were bonded with a hot melt adhesive, and the bonded portion was cut with a cutter across the width direction. Therefore, at the edge, the two sheets of the outer layer sheet and the inner layer sheet are joined with the hot melt adhesive to be in a sealed state.

[Comparative Example 3]
This comparative example is an example in which the heat seal part was not cut in Example 3 after the heat seal part was formed. In other words, the fused portion at the end edge remains heat sealed. The thickness T and width W of the fused part were as shown in Table 1 below.

[Evaluation]
About the diaper obtained by the Example and the comparative example, the air permeability of the edge part area | region of a ventral part and a back side part, bendability, softness, opening prevention property, and expansion-contraction followability were evaluated as follows. . The results are shown in Table 1 below.

(Breathability)
A sample cut to 30 mm × 30 mm or more was sandwiched between KES-F8-AP1 AIR PERMEABILITY TESTER (manufactured by KATO TECH), and the airflow resistance (R) at locations other than the fused portion was measured. The sample is cut from the ventral part or the dorsal part so that the end region and the edge are included, and in the respective exterior bodies of the ventral part and the dorsal part, a plurality of overlapping parts are avoided to avoid the fusion part All the sheets were measured together. The obtained value was applied to the following formula and converted into air permeability (S). The measurement was performed on three samples and the average was obtained.
S = 12.5 / R

[Ease of bending]
Sensory evaluation shows that it is easy to bend when it is held and bent so that there is no side seal between them with a gap of about 5 cm so that the product X direction of the end area of a given sample is a bent line. The average score when five women were evaluated was calculated. Each sample was scored. In addition, the score was given by absolute evaluation of each individual.

〔soft〕
The softness of the edge portion of a given sample was evaluated by having five women stroke the end with a forefinger with a weak force to trace the end in the product Y direction. The average score was calculated by 5 women who evaluated the softness at that time. Each sample was scored. In addition, the score was given by absolute evaluation of each individual.

(Opening prevention)
The mouth opening prevention property was evaluated by measuring the maximum value of the peel strength of the two-layer nonwoven fabric sandwiching the waist rubber at the waist end. Cut the waist end with a width of 30 mm and a length of 50 mm, peel off about 15 mm in advance, and sandwich each of the two layers between the upper and lower chucks of the product name “RTC-1150A TENSILON” manufactured by ORIENTEC, at 300 mm / s The maximum value of peel strength when pulled was measured. The measurement was performed on three samples and the average was obtained. As a measurement sample, when the length is less than 50 mm, the distance between chucks can be reduced for measurement.

[Extension / contraction followability]
It was visually evaluated whether or not the end of the waist follows the expansion and contraction of the sheet during expansion and contraction. The number of wrinkle waves generated by the contraction was compared between the region where the waist elastic member is located and the edge of the waist portion. Specifically, a portion having an arbitrary width of 30 mm excluding the side seal portion was selected. The number of waves (A) by the waist elastic member in that range and the number of waves at the edge (B) were counted to obtain a value (%) of B / A × 100. This measurement was performed for each sample. B / A × 100 means that the closer the value is to 100%, the better the stretchable followability.

  As is apparent from the results shown in Table 1, it can be seen that the diaper of each example has high air permeability, is easy to bend, is soft, and is excellent in mouth opening prevention and expansion / contraction followability. In contrast, in the diaper of Comparative Example 1 in which the end region was formed by folding the outer layer sheet and the inner layer sheet, the number of sheets constituting the end region was increased to five, so the air permeability was reduced. And it became difficult to bend again. The diaper of Comparative Example 2 whose end region was sealed with a hot melt adhesive also had poor air permeability due to the use of the hot melt adhesive, and was difficult to bend. In Comparative Example 3 in which the fused part was formed only by the heat seal part, the thickness of the heat seal part was increased, which caused difficulty in bending and inferior softness. In addition, the stretchability was low.

DESCRIPTION OF SYMBOLS 1 Pants type disposable diaper 1A Abdominal side 1B Back side 1Ae, 1Be End area 1At, 1Bt Edge F Front body R Rear body 2 Absorbent main body 3 Exterior body 31 Outer layer sheet 32 Inner layer sheet 3 'Exterior body precursor 4 Side seal part 40 Fusion part 40a Outer edge T of fusion part Thickness W of fusion part Width of fusion part 10 Diaper continuous body 20 Laser type joining device 21 Support member 26 Belt type pressure device 27 Opening

Claims (8)

It has a longitudinal direction and a width direction orthogonal to the longitudinal direction, and is provided with an abdominal side portion located on the abdomen side of the wearer when worn on one side of the longitudinal direction, and on the other side of the longitudinal direction, In disposable diapers with a dorsal part located at
The longitudinal direction end region in the ventral side portion or the dorsal side portion is composed of a laminated structure of a plurality of sheets, and the edge extending in the width direction in the end portion region is fused with the plurality of sheets. Consisting of the fused part
A disposable diaper in which the thickness of the fused part is smaller than the sum of the individual thicknesses of the plurality of sheets constituting the fused part. Both the ventral part and the dorsal part are composed of a laminated structure of a plurality of sheets,
The disposable diaper according to claim 1, wherein the fusion part in the ventral part and the dorsal part is formed separately. An elastic member extending in the width direction is disposed between the plurality of sheets at a position spaced inward in the longitudinal direction from the edge on the ventral side or the back side,
The disposable diaper according to claim 1 or 2, wherein there is no adhesive for fixing the two sheets sandwiching the elastic member between the edge and the elastic member.   The disposable diaper according to any one of claims 1 to 3, wherein a sharp portion is not observed when a cross section of the edge extending in the longitudinal direction is observed along the thickness direction of the plurality of sheets.   The disposable diaper according to any one of claims 1 to 4, wherein a thickness / width value, which is a ratio of a thickness to a width of the fused portion, is 1 or more.   The disposable diaper according to any one of claims 1 to 5, wherein the fusion part has a protrusion toward a non-skin facing surface. An elastic member extending in the width direction is disposed between the plurality of sheets in the longitudinal end region in the ventral side or the back side, whereby the ventral side or the back side is in the width direction. Can be stretched along,
The disposable according to any one of claims 1 to 6, wherein when the ventral part or the dorsal part is expanded and contracted along the width direction, the fusion part is deformable in response to the expansion and contraction. Diapers. The disposable diaper has a pair of side seal portions, a waist opening, and a pair of legs, wherein left and right side edges along the longitudinal direction of the abdominal side and left and right side edges along the longitudinal direction of the back side are joined. A pants-type diaper in which an opening is formed,
The disposable diaper according to any one of claims 1 to 7, wherein the fused portion forms an edge of the waist opening.

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