AU2014332820B2

AU2014332820B2 - Disposable pant-type wearing article

Info

Publication number: AU2014332820B2
Application number: AU2014332820A
Authority: AU
Inventors: Katsufumi Aoki; Hideaki Maki; Noriko NAGASE; Shunsuke Takino; Toshiyasu Yoshioka
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2013-10-11
Filing date: 2014-10-10
Publication date: 2019-05-23
Anticipated expiration: 2034-10-10
Also published as: MY173670A; JP5934864B2; WO2015053404A1; CN105611906B; BR112016005766B1; JP6465824B2; CN105611906A; JP2015096192A; SA516370884B1; BR112016005766A2; JP2016107117A; AU2014332820A1

Abstract

The purpose of the present invention is to provide a disposable underpants-type wearable article which is easily removed. Side edge parts of sheets forming a front waist region and a rear waist region of a wearable article, such as a disposable underpants-type nappy, overlap each other so as to form a chevron shape, and are welded together at joint spots (30). Each of the sheets includes at least two sheets of non-woven fabric, and at least one of said sheets of non-woven fabric is employed such that the tensile strength thereof in a vertical direction is lower than the tensile strength thereof in a horizontal direction. The joint spots (30) have a size in the vertical direction (A) which does not exceed 1.5 mm, and a size in the horizontal direction (B) which does not exceed 3 mm. Furthermore, the joint spots (30) form a column (40) such that inner end parts (33) thereof extend in the vertical direction and are in contact with a single virtual straight line (35). Moreover, the joint spots (30) form side-part seam regions (25) of the nappy.

Description

{Title of Invention} DISPOSABLE PANT-TYPE WEARING ARTICLE {Technical Field} { 0001 }

The present invention relates to disposable pant-type wearing articles and more specifically to disposable panttype wearing articles in which a front waist region and a rear waist region are welded to each other along both side edges thereof.

{Background} {0002}

A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was known or that 15 the information it contains was part of the common general knowledge as at the priority date of any of the claims.

{0002a}

Disposable pant-type wearing articles such as a disposable pant-type diapers in which respective side edges 20 of front and rear waist regions are joined to each other are conventionally known. The wearing articles in which the front and rear waist regions may be separated from each other along the respective welded side edges to take off the articles are also conventionally known.

la

2014332820 03 Mar 2016 { 0003}

For example, in the pant-type disposable diaper disclosed in Japanese Utility Model Application Laid-Open Publication H7-34814 (Patent Literature 1), at least a part of welded 5 spots has a V-shape pointed in a lateral direction of the diaper. According to the disclosure, when the diaper is taken off, the diaper may be torn off at the welded spots.

2013-214234 { 0004 }

The pant-type disposable diaper disclosed in JP H10-52458 (Patent Literature 2) has a plurality of joint-blocks at which a front waist region and a rear waist region are joined to each other. Each of the joint-blocks has a shape of a laterally-facing isosceles triangle. The joint-blocks are arranged in a vertical direction of the diaper in a manner that an apex angle of the isosceles triangle alternately turns over to become right-pointing and left-pointing in a lateral direction. According to the disclosure, both the side edge portions may be easily peeled off.

{0005}

In the pant-type wearing article disclosed in JP 2008-136651 (Patent Literature 3), each side seal region includes a joint-spot having the minimum seal-width between an upper end portion and a lower end portion. A seal-width of the joint-spots other than the minimum width joint-spot is gradually reduced from the upper end portion and the lower end portion of the side seal region toward the minimum width joint-spot. The joint-spot has a width ranging 3 to 15 mm and a height ranging 0.1 to 3 mm. To take off the wearing article, the seal region may be torn apart, according to the disclosure.

{0006}

In the pant-type disposable diaper disclosed in JP 2009-131539

2013-214234 (Patent Literature 4), a front waist region and a rear waist region are welded to each other along respective lateral portions to define side seal regions. In each of the side seal regions, a plurality of linear heat-seal spots are arranged in a vertical direction at given intervals to define a straight broken line. To take off the diaper, the side seal regions may be torn apart, according to the disclosure.

{Citation List} {Patent Literature} { 0007 }

{PTL	1} :	JP	JUT H7-34814
{PTL	2} :	JP	H10-52458 A
{PTL	3} :	JP	2008-136651 A
{PTL	4} :	JP	2009-131539 A

{Summary} {Technical Problem} { 0008 }

When it is tried to take off the pant-type wearing article in which the side edge portions of nonwoven fabrics respectively defining the front and rear waist regions are welded to each other, sometimes the side edges themselves are peeled off from each other as the front waist region and the rear waist region gripped in the vicinity of the side edge portions are pulled in a front-back direction. However, in some cases, the fibers

2014332820 03 Mar 2016 forming the nonwoven fabrics may be broken around portions in which the fibers forming the nonwoven fabrics are welded together or such peeling off and break may occur concurrently or continuously. In the operation to separate 5 the side edges from each other, the nonwoven fabrics may be torn in the vertical direction or in the lateral direction, preventing the side edge portions from being smoothly separated in the front-back direction. For a few months

aged infant or	baby	having a	flexible	body, a direction in
10 which a	force	is	impressed	to the	diaper in	order to
separate	the	side	edge portions may become	unstable,

preventing the side edge portions from being quickly separated from each other. Further, the side edge portions may be abruptly torn and body exudates may suddenly flow 15 from the inside of the diaper outward. Though the prior art facilitate the side edge portions welded together to be torn or separated, it is not adequately considered for the infant or baby having a flexible body.

{ 0009}

It is therefore desirable to improve such known disposable pant-type wearing articles, thereby providing a disposable pant-type wearing article arranged so that side edge portions of the wearing article along which respective sheets defining front and rear waist regions respectively,

2014332820 30 Apr 2019 are dotted and welded to each other may be easily and smoothly separated from each other in top-to-bottom or bottom-to-top mode, thereby making it easy to put the article on a body of a wearer such as an infant and to take 5 off the article from the wearer's body.

{0010}

According to the present invention there is provided a disposable pant-type wearing article including sheets to

define a front waist	region and	. a	rear	waist	region, each
10 having a	vertical	direction	and	a	lateral	direction,
respective	side edge	portions	of	the	sheets	being fixed

together at a plurality of joint-spots arranged in the vertical direction so as to define a pair of lateral seam regions extending in the vertical direction and opposed to 15 each other, wherein:

the respective sheets defining the front waist region and the rear waist region are at least two sheets of nonwoven fabric made of thermoplastic synthetic fibers having a fineness ranging 0.1 to 4 dtex and a mass per unit 20 area ranging 7 to 25 g/m² and, in at least one of the at least two sheets of nonwoven fabrics, a tensile strength in the vertical direction is lower than a tensile strength in the lateral direction;

a dimension in the lateral direction of the lateral seam

2014332820 30 Apr 2019 region is 3 mm or less; and each of the joint-spots in the lateral seam region has a dimension in the vertical direction of 1.5 mm or less, the innermost end portions of the respective joint-spots are in contact with an imaginary line rectilinearly extending in the vertical direction so as to define a column extending in the vertical direction and, in the column, the minimum interval between a pair of the joint-spots adjacent in the vertical direction is in a range 0.4 to 5 mm;

the sheets have cut ends on opposite sides thereof and are fixed to each other in the cut ends;

seam-free regions not joining the side edges to each other are formed between the lateral seam region and the cut end in the lateral direction;

a plurality of elastic members extending in a waistsurrounding direction is located between the two sheets of the nonwoven fabrics in the front waist region and the rear waist region; and a sleeve-like bulge extending in the vertical direction is formed in the seam-free region under contraction of a plurality of the elastic members extending in the lateral direction .

{0011}

Intentionally left blank.

6a

2014332820 30 Apr 2019 {Advantageous Effects of Invention} {0012}

In the disposable pant-type wearing article according to the present invention, the side edge portions of sheets respectively defining the front waist region and the rear waist region are welded to each other at a plurality of joint-spots each having a small dimension in the vertical direction as well as in the lateral direction and arranged to form the column in the vertical direction. Each of the sheets includes at least two nonwoven fabrics having a fineness of thermoplastic synthetic fibers thereof ranging 0.1 to 4 dtex and a mass per unit area ranging 7 to 25 g/m². As one of these two nonwoven fabrics, the nonwoven fabrics having a tensile strength lower in the vertical direction than in the lateral direction are used. The joint-spots formed on these nonwoven fabrics have the inner end portions arranged along an imaginary line rectilinearly

2013-214234 extending in the vertical direction of the wearing article thereby form a column of the joint-spots. When it is desired to take off the wearing article from the wearer, the front waist region and the rear waist region may be held by hands in the vicinity of the joint-spot column and pulled in the front-back direction, thereby the nonwoven fabrics welded to each other may begin to be broken in the peripheral edges of the respective joint-spots each having a small dimension in the lateral direction and in the vertical direction or may be peeled off from each other at the joint-spots. In this way, the front waist region and the rear waist region are easily and smoothly separated from each other.

{Brief Description of Drawings} {0013}

The drawings illustrate specific embodiments of the present invention including optional and preferred embodiments as well as essential features of the invention.

{Fig. 1} Perspective view of a disposable diaper as an example of the pant-type wearing article according to the present invention .

{Fig. 2} Partially cutaway plan view of the diaper flatly extended from the state in Fig. 1.

{Fig. 3} Scale enlarged diagram of a portion III in Fig. 2.

{Fig. 4} Scale enlarged diagram viewed in a direction

2013-214234 indicated by two arrows IV-IV in Fig. 1.

{Fig. 5} Partially cutaway plan view similar to Fig. 2 exemplarily illustrating another embodiment.

{Fig. 6} Scale enlarged diagram of a portion VI in Fig. 5.

{Fig. 7} Scale enlarged diagram exemplarily illustrating a portion VII in Fig. 1.

{Fig. 8} Schematic diagram illustrating steps (a), (b) and (c) followed to measure a force needed to separate front and rear waist regions from each other.

{Fig. 9} Graphic diagram illustrating measurement results (a) and (b) of the force needed to separate the front and rear waist regions from each other.

{Description of Embodiments} {0014}

Details of a disposable pant-type wearing article according to the present invention is described hereunder.

{0015}

Fig. 1 is a perspective view illustrating a pant-type diaper 10 as an example of the disposable pant-type wearing articles. The diaper 10 illustrated in Fig. 1 in a manner that a waist opening 27 to be hereinafter described may be recognized has a front waist region 21 defined by a front panel 11, a rear waist region 22 defined by a rear panel 12 and a crotch region 23 defined by a crotch panel 13. The front panel 11 has side edge

2013-214234 portions 24 on both sides in a lateral direction B and the rear panel 12 has side edge portions 26 on both sides in the lateral direction B. On both the sides in the lateral direction B, the side edge portions 24 and the side edge portions 26 facing the formers are welded to each other at a plurality of joint-spots 30 (see Fig. 2) arranged in a vertical direction A to define a waist opening 27. The joint-spots 30 arranged in the vertical direction A define lateral seam 25 in the diaper 10. The crotch panel 13 has a front end portion 14 and a rear end portion 16 (see Fig. 2) bonded to respective interior surfaces of the front panel 11 and the rear panel 12, i.e., respective interior surfaces of the front waist region 21 and the rear waist region 22. A portion of the crotch panel 13 extending down from these waist regions 21, 22 defines the crotch region 23. The crotch region 23 cooperates with the front waist region 21 and the rear waist region 22 to define a pair of leg-openings 28 . A plurality of gathers 31, 32 are formed in the front waist region 21 and the rear waist region 22 under contraction of waist-elastic members 44, 54 to be described hereunder. In the crotch region 23 also, a plurality of gathers 36 are formed on peripheries of the respective leg-openings 28 under contraction of leg-opening elastic members 68 to be described hereunder. In Fig. 1, a vertical direction, a lateral direction and a front-back direction of the diaper 10 are indicated by

2013-214234 double-headed arrows A, B and C. The term pant-type wearing article according to the present invention means a wearing article having a waist-opening and a pair of leg-openings and adapted to be put on the wearer's body by pulling up the article along the wearer's legs after the wearer's legs have been inserted through these leg-openings.

{0016}

Fig. 2 is a partially cutaway plan view illustrating an interior surface side of a flatly extended diaper 10a obtained by flatly extending the diaper 10 in Fig. 1 in the lateral direction B and the front-back direction C after the front waist region 21 and the rear waist region 22 have been separated from each other along columns of the joint-spots 30. Respective shapes of the diaper 10 and the flatly extended diaper 10a are substantially symmetric about a center line P bisecting a dimension in the lateral direction B. The term substantially used herein means that a certain degree of unsymmetricity of the shape about the center line P is permissible as long as there is no possibility that such unsymmetricity poses a problem for putting on or disposal of the diaper 10.

{0017}

In Fig. 2, the front waist region 21 is defined at least by two sheets, i.e., an interior sheet 41 facing skin of the wearer (not shown) and an exterior sheet 42 facing garment (not shown)

2013-214234 and has side edge portions 24 of these sheets 41, 42 and cut ends 43 corresponding to cut lines of these interior sheet 41 and exterior sheet 42. Between the interior sheet 41 and the exterior sheet 42, a plurality of waist-elastic members 44 inclusive of waist-opening elastic members 44a and auxiliary elastic members 44b are interposed in a state extended in the lateral direction B . The waist-elastic members 44 extend to both the side edge portions 24, preferably to the cut ends 43 and are bonded to at least one of these two sheets 41, 42 with hot melt adhesive (not shown). Along both the side edge portions 24, columns 40 of the joint-spots 30 arranged in the vertical direction A are illustrated. The interior sheet 41 and the exterior sheet 42 are bonded to each other by hot melt adhesive 81 (see Fig. 7) distributed to one of these sheets 41, 42 in a dot-pattern or linear pattern.

{0018}

The rear waist region 22 is formed of at least two sheets,

i.e., an interior sheet 51 facing the wearer's skin and an exterior sheet 52 facing the garment and, on both sides in the lateral direction B, has the side edge portions 26 of these sheets 51, 52 and cut ends 53 corresponding to cut lines of these sheets 51, 52. Between the interior sheet 51 and the exterior sheet 52, a plurality of waist elastic members 54 inclusive of waist-opening elastic members 54a and auxiliary elastic members

2013-214234

54b are interposed under extension in the lateral direction X.

The waist elastic members 54 extend to both the side edge portions 26, preferably to the cut ends 53 and bonded to at least one of both the sheets 51, 52 by hot melt adhesive (not shown) . Along both the side edge portions 26, the respective columns 40 of the joint-spots are illustrated. The respective columns 40 of the joint-spots along both the side edge portions 26 overlap with the respective columns 40 of the joint-spots along both the side edge portions 24 in the diaper 10 to define the lateral seam 25 of the diaper 10. The interior sheet 51 and the exterior sheet 52 are bonded to each other by hot melt adhesive 82 (see Fig . 7) .

{0019}

The interior sheet 41 and the exterior sheet 42 defining the front waist region 21 and the interior sheet 51 and the exterior sheet 52 defining the rear waist region 22 are formed of nonwoven fabric thermoplastic synthetic fibers, for example, spun bond nonwoven fabrics or spun bond/melt blown/spun bond nonwoven fabrics. The thermoplastic synthetic fibers having a fineness ranging 0.1 to 4 dtex and a mass per unit area ranging 7 to 25 g/m², preferably ranging 9 to 15 g/m² is used. Use of the nonwoven fabrics having a mass per unit area ranging 7 to 25 g/m^e is preferable in order to ensure a comfortable texture and a high breathability of the front waist region 21 and the rear waist

2013-214234 region 22. The interior sheet 41 and the exterior sheet 42 and/or the interior sheet 51 and the exterior sheet 52 may be formed by overlapping two layers of nonwoven fabric or by folding back a single layer along a upper side edge 21a of the front waist region 21 and/or along a upper side edge 21a of the rear waist region 22 . In any instance, the present invention specifies that the side edge portions 24 of the front panel 11 and the side edge portions 26 of the rear waist region 12 are formed of two sheets of nonwoven fabrics. Though not illustrated, it is possible to use additionally nonwoven fabrics made of thermoplastic synthetic fibers in the front waist region 21 and/or the rear waist region 22, more specifically, so as to extend between both the side edge portions 24 and/or between both the side edge portions 26, if necessary. A dimension in the vertical direction A of the additionally used nonwoven fabrics may be smaller than the dimension in the vertical direction A of the front panel 11 and/or the rear panel 12. Both the side edge portions 24 and/or both the side edge portion 26 arranged in this manner are regions in which at least two nonwoven fabrics overlap with each other.

{0020}

In the continuous production of the diaper 10, the respective members such as nonwoven fabrics to be used in the diaper are fed in the direction corresponding to the lateral direction B

2013-214234 of the diaper 10 . When the nonwoven fabrics are fed in this manner, the nonwoven fabrics in the diaper 10 are apt to have a tensile strength in the vertical direction lower than a tensile strength in the lateral direction. For this reason, the nonwoven fabrics defining the front waist region 21 and the nonwoven fabrics defining the rear waist region 22 inevitably include at least one nonwoven fabric having a tensile strength in the vertical direction A lower than a tensile strength in the lateral direction B. In the present invention, such differential tensile strength means that the thermoplastic synthetic fibers forming the nonwoven fabric apt to be oriented not in the vertical direction A but in the lateral direction B. For the reason that the nonwoven fabrics are in such potentiality, when the wearer grips the front waist region 21 and the rear waist region 22 with the hands at portions in the vicinity of the lateral seam 25 and tries to separate the front waist region 21 and the rear waist region 22 from each other, a force for this purpose acts to separate the thermoplastic synthetic fibers extending in the lateral direction B off from the peripheries of the joint-spots 30 or to break them along the peripheries of the joint-spots 30 so that one of the front waist region 21 and the rear waist region 22 may be easily broken along the peripheries of the respective joint-spots 30. Such separation and/or breakage may be repeated along the columns

2013-214234 of the joint-spots 30, and whereby the front waist region 21 and the rear waist region 22 may be easily separated along the all lateral seam 25. As the nonwoven fabrics in which the thermoplastic synthetic fibers are apt to be oriented not in the vertical direction A but in the lateral direction B, for example, spun bond nonwoven fabrics may be used and a machine direction in producing the nonwoven fabric may be aligned with the lateral direction B. In this regard, such nonwoven fabrics and the front and rear waist region 21, 22 using such nonwoven fabrics tear easily in the lateral direction B.

{0021}

The tensile strength of the nonwoven fabrics used in the diaper 10 may be comparatively measured as is described below. The front and rear waist regions 21, 22 are cut off from the diaper 10 and immersed in toluene solution to solve the hot melt adhesives used therein. Then, the nonwoven fabrics are separated one from another and dried. From the respective nonwoven fabrics, a vertically long test piece having a dimension in the vertical direction A of about 70 mm and a dimension in the lateral direction B of about 25 mm, and a laterally long test piece having a dimension in the vertical direction A of about 25 mm and a dimension in the lateral direction B of about 70 mm are prepared. A distance between a pair of chucks of a tensile tester (e.g., AUTOGRAPH AG-X plus

2013-214234 or equivalents thereof) is set to 50 mm and both ends 10 mm in the vertical direction of each test piece are gripped by the respective chucks and the test piece is stretched at a pulling rate of 100 mm/min to measure a breaking load (N). For the respective test pieces, a ratio (N/WD) of the breaking load (N) to the width (WD) having accurately measured prior to the tensile test is calculated as a tensile strength and values of the tensile strength obtained from the respective test pieces are compared to each other.

{0022}

Referring to Fig. 2, the crotch panel 13 defining the crotch region 23 has a liquid-permeable interior sheet 61 facing the wearer's skin, an exterior sheet 62 facing the garment, body exudates absorbent core 63 lying immediately under the interior sheet 61 and a liquid-impermeable leakage-barrier sheet 64 lying between the exterior sheet 62 and the core 63 . The interior and exterior sheets 61, 62 respectively cover the interior and exterior surfaces of the core 63, extend outward beyond a peripheral edge of the core 63 and are overlapped and bonded to each other outside by hot melt adhesives (not shown) to define a front end edge 65, a rear end edge 66 and both side edges 67 of the crotch panel 13. Inside both the side edges 67, the leg-elastic members 68 extending under tension in the front-back direction C (see Fig. 1) are bonded to at least one

2013-214234 of the interior and exterior sheets 61, 62 by hot melt adhesives (not shown). The front end portion 14 of the crotch panel 13 and the interior sheet 41 of the front waist region 21 are bonded to each other by hot melt adhesives (not shown) while the rear end portion 16 and the interior sheet 51 of the rear waist region 22 are bonded to each other by hot melt adhesives (not shown) . {0023}

Fig. 3 is a scale enlarged view of a portion III in Fig. 2 and the double-headed arrow A indicates the vertical direction in Fig. 1. In the side edge portion 26 of the rear panel 12 defining the rear waist region 22, the joint spots 30 and the column 40 of these joint-spots to define the lateral seam 25 are illustrated. Each of the joint-spots 30 is shaped in a parallelogram having an inner end portion 33 facing a center line P (see Fig. 2) bisecting the dimension in the lateral dimension B of the flatly extended diaper 10a and an outer end portion 34 facing the cut end 53 wherein the inner end portion 33 and the outer end portion 34 are parallel to one another and, between the inner and outer end portions 33, 34, an upper side 38 and a base side 39 extend in parallel to each other on the down-grade toward the cut end 53. The inner end portion 33 adjoins an imaginary straight line 35 extending in parallel to the center line P or extending in the vertical direction so as to intersect with the center line P. A distance L in the lateral

2013-214234 direction B between the imaginary straight line 35 and the cut end 53 is a range 4 to 13 mm. A dimension M in the vertical direction A parallel to the center line P is 1.5 mm or less and a dimension W in the lateral direction B orthogonal to the center line P is the same as or larger than the dimension M, but preferably 2.5 mm or less. In other words, the dimension in the vertical direction A and in the transverse direction B is relatively small, particularly, the dimension in the vertical direction is small, a circumferential length is short and an area also is small. A dimension Q in the lateral direction B of the lateral seam 25 including such joint-spots 30 is 3 mm, preferably 2.5 mm or less. The minimum distance dimension N in the vertical direction A between each pair of the adjacent joint spots 30 ranges 0.4 to 5 mm and is preferably adjusted so as to be sufficiently larger than the width of the waist-elastic member 54 to lay it therebetween. In Fig. 3, the width of the elastic members 54 is a dimension thereof in the vertical direction A.

{0024}

A shape of the joint-spot 30 is not particularly specified and various shapes such as a circle and an oval as well as parallelogram inclusive of a rectangle and a square may be used. However, the exemplarily illustrated joint-spot 30 having a shape defining, in its entirety, a descending slope from the

2013-214234 inner end portion 33 toward the cut end 53 wherein the inner end portion 33 has an acute-angled apex 33a is preferable for the reason that it is possible for such joint-spot 30 to concentrate the force to separate the front and rear waist regions 21, 22 from each other to a limited range, thereby speeding up the separation. The dimensions Μ, N and W may be measured by a bench rule or a slide caliper or through a graduated loupe of 10 magnifications. The region of the diaper 10 to be measured is preferably fixed, under tension in the vertical direction A and the lateral direction, to adhesive surface of pressure-sensitive adhesive tapes.

{0025}

Between the lateral seam 25 and the cut end 53 in the lateral direction B, a seam-free region 29 in which neither the joint-spots 30 nor extra joint-spots 70 (see Fig. 6) to be described later are formed. A dimension R in the lateral direction B of the seam-free region 29 is preferably larger than the dimension Q in the lateral direction B of the lateral seam 25.

{0026}

In the respective side edge portions 24, 26, by setting the dimension R of the seam-free region 29 to be larger than the dimension R of the lateral seam 25, it is conceivable that a breakage of the front waist region 21 and/or the rear waist

2013-214234 region 22 in the lateral direction B may be restricted when it is tried to separate the front and rear waist regions 21, 22 in the lateral seam 25. If the dimension R is relatively small and the cut ends 43, 53 are relatively close to the lateral seam 25, breakage occurring in the lateral direction B along the upper side 38 and/or the base side 39 of the joint-spot 30 in the front waist region 21 and/or the rear waist region 22 may extend even further and easily reach the cut ends 43, 53 . A force further impressed upon the front and rear waist regions 21, 22 is concentrated upon the inner end portions of the respective tears as viewed in the lateral direction B, whereby, it is conceivable that the breakage may easily extend inward and, in consequence, the front waist region 21 and/or the rear waist region 22 may be easily broken in the lateral direction B. If the dimension R of the seam-free region 29 is sufficiently large, there is no possibility that the breakage may easily reach the cut ends 43, 53 and, it is conceivable, that the force impressed upon the front and rear waist regions 21, 22 is not concentrated to the innermost ends in the lateral direction B of the respective broken places.

{0027 }

In the diaper 10 of Fig. 1 transformed from the flatly extended diaper 10a of Fig. 2, the side edge portions 24, 26 overlapping with each other remain in not joined state at each pair of the

2013-214234 adjacent joint spots 30 in the vertical direction A. These joint spots 30 and the nonwoven fabric exposed between the respective pairs of the adjacent joint-spots are alternately arranged in the vertical direction A to define the lateral seam 25 in the diaper 10 (see Fig. 1). In Fig. 3, the side edge portions 26 include the waist-elastic members 54 extending in a stretched state and, in an example of the preferred side edge portion 26, the waist-elastic members 54 included in the side edge portion are contractibly bonded to the interior sheet 51 and/or the exterior sheet 52 by hot melt adhesives (not shown) to any one of the interior sheet 51, the exterior sheet 52 and the waist-elastic members 54. Consequently, in the side edge portions 26 of the diaper 10 obtained from the flatly extended diaper 10a, gathers and curls are formed in the interior sheet 51 and the exterior sheet 52 under contraction of the waist-elastic members 54 between the cut end 53 and the outer end portion 34 of the joint-spot 30, in other words, between the cut end 53 and the lateral seam 25. In the diaper 10 put on the wearer's body, these gathers and curls may shield the join-spots 30 and may protect the wearer's skin from a direct contact with the stiff joint-spots 30.

{0028}

Upon the transformation from the flatly extended diaper 10a to the diaper 10, the joint spots 30 and the columns 40 of these

2013-214234 joint-spots 30 in the side edge portions 24 of the front panel 11 in Fig. 2 are unified with the joint spots 30 and columns 40 of these joint-spots 30 in the side edge portions 26 to form the lateral seam 25. In view of this, though not illustrated, the joint-spots 30 in the front panel 11 also have the inner end portions and the outer end portions corresponding to the inner end portions 33 and the outer end portions 34 in the rear panel 12, respectively, wherein these inner end portions are adjoined to the imaginary straight line 35 and have the same dimensions W, M and N as those in the rear panel 12 . The straight line 35 is imaginary line which is assumable in the side edge portions 26 and 24. The side edge portions 24 also include the waist-elastic members 44 under tension and, in a preferable example of the side edge portions 24, the waist-elastic members 44 extend to the cut ends 43.

{0029}

In the diaper 10, the cut ends 43 and the cut ends 53 shown in the flatly extended diaper 10a may be welded to each other as described later in detail. In such diaper 10, the interior sheet 41 and the exterior sheet 42 of the front panel 11 contract together in the lateral direction B in the seam-free regions 29 defined between the cut ends 43, 53 heat-sealed together and the lateral seam 25, and simultaneously in the seam-free regions 29 of the rear panel 12 also, the interior sheet 51 and the

2013-214234 exterior sheet 52 contract together in the lateral direction B, whereby a pair of puff 45 (see Fig. 4) extending in the vertical direction A are formed by the side edge portions 24, 26 on the outer side of the lateral seam 25 . These puffs 45 soften a texture of the side edge portions 24, 26 in the diaper 10 and shield the joint-spots 30 so that the appearance of the diaper 10 may look high-class. In order that the seam-free regions 29 may form the puff 45, the lateral seam 25 is preferably 4 to 10 mm distanced from the cut ends 43, 53.

{ 0030 }

Fig. 4 is a diagram viewed in a direction indicated by two arrows IV-IV in Fig. 1 and exemplarily illustrates the diaper 10 having the puff 45 formed by the side edge portion 24 and the side edge portion 26. The side edge portion 24 and the side edge portion 26 are welded to each other at the respective joint-spots 30 to form unitary structure inclusive of the joint-spot column 40 and the lateral seam 25. On the outside in the lateral direction B of the lateral seam 25, the cut end 43 and the cut end 53 are welded to each other to form a joint line 46 extending in the vertical direction A in parallel to the lateral seam 25. Under contraction of the waist-elastic members 44, 54 between the lateral seam 25 and the joint line 46, the side edge portions 24, 26 are convexly curled in opposite directions so as to form the puff 45 along the side edge 24 of

2013-214234 the diaper 10. In the diaper 10 put on the wearer's body, the lateral seam 25 is shielded by the puff 45 against being recognized from an obliquely lateral position and against being recognized from a lateral position. In some instances, the lateral seam 25 may be shielded by the puff 45 also against being recognized from the back and the front. The puff 45 is elastically deformed under a pressing force and restores the shape in Fig . 4 upon removal of the pressing force. It is possible for such puff 45 to make a texture of the lateral seam 25 soft. In this regard, assuming that the cut ends 43, 53 are left without being welded to each other as seen in the embodiment illustrated, the side edge portions 24, 26 form curls and/or gathers not in an integrated manner but in an uncoordinated manner, whereby the shape of the cut ends is liable to become so irregular that the diaper 10 may be disfeatured.

{0031 }

To form the joint-spots 30 in the diaper 10, various means commonly used in the relevant technical field may be used. For example, composite web formed of first web in which the front panels 11 not yet formed with the joint-spots 30 are contiguously arranged in the lateral direction B overlaps with second web in which the rear panels 12 also not yet formed with the joint-spots 30 are continuously arranged in the lateral direction B is supplied in a machine direction and guided so

2013-214234 as to pass through the ultrasonic welder commonly used in the relevant technical field. In such composite web, the machine direction in manufacturing the nonwoven fabric used therein is brought in line with the machine direction for the composite web. For this reason, the fiber orientation in the nonwoven fabrics forming the composite web is in line with the machine direction for the composite web.

{0032}

As the ultrasonic welder, a horn-roll and an anvil-roll both rotating in the machine direction are used. The horn-roll has protrusions arranged on a peripheral surface thereof and functioning as horns thereby forming the joint-spots of a given shape on the composite web. The composite web formed with the joint-spots is cut at a position at which the dimension of the composite sheet in the machine direction corresponds to the dimension of the diaper 10 in the lateral direction B. A cutter used to cut the composite web may be heated to an appropriate temperature, as needed, so that the cut end 43 of the front waist region 21 may be welded to the cut end 53 of the rear waist region 22 in cutting the composite web and thereby the sleeve-like bulge may be formed. In this regard, it is also possible to practice the present invention without welding the cut ends 43, 53 to each other.

{ 0033}

2013-214234

When it is desired to take off the diaper 10 exemplarily illustrated in Fig. 1, a force is impressed upon the front waist region 21 and the rear waist region 22 held by respective hands at the upper end portions of the respective side edge portions 24, 26 so that the front waist region 21 may be pulled forward and the rear waist region 22 may be pulled rearward, whereby the front and rear waist regions 21, 22 may be separated from each other. It is also possible to impress a force upon the front waist region 21 and the rear waist region 22 held by respective hands at the lower end portions of the respective side edge portions 24, 26 so that the front waist region 21 may be pulled forward and the rear waist region 22 may be pulled rearward. By separating off the front waist region 21 and the rear waist region 22 from each other in this manner at the joint spots 30, it becomes unnecessary to pull down the diaper 10 along the legs to take off the diaper 10. In pulling off the front waist region 21 and the rear waist region 22 from each other, the pulling force is concentrated on the peripheral edge of the joint-spot 30 located in the upper end portion or the lower end portion of the joint-spot column 40 and having a small area.

{0034 }

For this reason, under a situation that the front waist region 21 and the rear waist region 22 are easily separated from each other at the joint-spots 30, the front waist region 21 and the

2013-214234 rear waist region 22 may be separated there from each other in the front-back direction C. The respective joints-spots 30 have a small area and the inner end portions 33 of the joint- spots 30 are arranged along the imaginary straight line 35 in Fig. 2 so that a separation of the front waist region 21 and the rear waist region 22 from each other may go on smoothly and substantially in a linear fashion from the waist-opening 27 toward the leg-openings 28 or from the leg-openings 28 toward the waist opening 27. When the respective joint-spots 30 have the acute-angled apex 33a as exemplarily illustrated in Fig. 3, a caretaker's force intending to separate the front waist region 21 and the rear waist region 22 from each other is concentrated into an extremely narrow region defined by the apex 33a and the vicinity thereof so that a work for separation of the front waist region 21 and the rear waist region 22 from each other may be notably alleviated.

{0035}

Under a situation that it is impossible or not easily to separate the front waist region 21 and the rear waist region 22 from each other at the joint-spots 30, thermoplastic synthetic fibers (not shown) contained in the fibers of the nonwoven fabrics forming the front waist region 21 and/or the rear waist region 22 and extending across the joint-spots 30 may be broken by the operator's force along the peripheral edges

2013-214234 of the joint-spots 30 to separate the front waist region 21 and the rear waist region 22 from each other. The respective joint-spots 30 have a small dimension in the vertical direction and in the lateral direction and a short boundary length, added to which the joint-spots 30 are linearly arranged to define the column 40 so that a separation of the front waist region 21 and the rear waist region 22 from each other may go on smoothly and substantially in a linear fashion in parallel to the imaginary straight line 35. When the nonwoven fabrics formed of fibers having a fineness ranging 0.1 to 4 dtex and used in the front waist region 21 and/or the rear waist region 22 have a mass per unit area as low as ranging 9 to 15 g/m², the number of fibers to be broken along the peripheral edges of the joint-spots 30 is fewer than those in the nonwoven fabrics having a mass per unit area higher than the former, and, in consequence, the separation may go on further smoothly.

{0036}

The diaper 10 making it possible to separate the front waist region 21 and the rear waist region 22 from each other so smoothly as described above is suitable to be used for younger babies and babies having flexible bodies. From a viewpoint of the diaper's size, the diaper 10 having a dimension from the uppermost waist-elastic member 44 in the front waist region 21 to the uppermost waist-elastic member 54 in the rear waist

2013-214234 region 22 measured in parallel to the center line P-P ranging 300 to 540 mm is suitable for the above-mentioned wearers. {0037 }

Fig. 5 is a view similar to Fig. 2, exemplarily illustrating another embodiment and Fig. 6 is a scaled-enlarged diagram of a portion VI in Fig. 5. In Fig. 5, a flatly extended diaper 10b different from the flatly extended diaper 10a with respect to the arrangement of the lateral seam 25 . Except this arrangement, it is possible to obtain the diaper 10 having the outer shape exemplarily illustrated in Fig. 1 from the flatly extended diaper 10b in the same manner as from the flatly extended diaper 10a. In the flatly extended diaper 10b, the lateral seam 25 has an upper portion 40a, an intermediate portion 40b and a lower portion 40c wherein the intermediate portion 40b occupies at least 1/4 of an entire length in the vertical direction A of the lateral seam 25. Both the upper portion 40a and the lower portion 40c have, in addition to the joint-spots 30 exemplarily illustrated in Figs. 2 and 3, columns of the extra joint-spots 70 arranged therein wherein the upper portion 40a and the lower portion 40c respectively occupy a range 1/10 to 1/2 of the entire length in the vertical direction A of the lateral seam 25, preferably a range 1/10 to 1/4. The extra joint-spots 70 preferably have shapes the same as or similar to the joint-spots 30 and arranged in the lateral seam 25 having a dimension in

2013-214234 the lateral direction B of 3 mm or less wherein the respective extra joint-spots 70 have a dimension m in the vertical direction A of 2 mm or less, a dimension w in the lateral direction B ranging 1.5 to 3 mm and the minimum distance dimension n between a pair of the adjacent extra joint-spots in the vertical direction A ranging 2 to 5 mm. In the flatly extended diaper 10b, the lateral seam 25 has the column of the joint-spots 30 and the column of the extra joint-spots 70 in the upper portion 40a and in the lower port ion 40c. In this regard, it is possible in the flatly extended diaper 10b to arrange the joint-spots 30 and the extra joint-spots arranged in columns in the intermediate portion 40B also.

{0038 }

To put the diaper 10 on her infant, mothers sometimes try to outspread the waist-opening as wide as possible with both hands . In such an instance, a strong force possibly separating the front waist region 21 and the rear waist region 22 from each other temporarily acts on the upper portion 40a of the lateral seam 25. The extra joint-spots 70 arranged in the upper portion 40a in Figs. 5, 6 are used to avoid a separation of the front waist region 21 and the rear waist region 22 from each other possibly occurring in such an instance. In this regard, to prevent the extra joint-spots 70 from interfering with a desired separation of the front and rear waist regions 21, 22 when it

2013-214234 is desired to take off the diaper 10, an area of the individual extra joint-spot 70 and the number of the extra joint-spots 70 are preferably minimized. Further, also in the flatly extended diaper 10b exemplarily illustrated in Figs. 5 and 6, the seam-free regions 29 are formed in the side edge portions 24,

26. While the dimension R of the seam-free region 29 in Fig.

is smaller than the dimension Q of the lateral seam 25, it is also possible to practice the present invention in a manner that the dimension R is larger than the dimension Q.

{0039}

In putting the diaper 10 on the infant, the infant's legs are sometimes caught by the peripheral edges of the leg-openings 28 and a force possibly causing the front waist region 21 and the rear waist region 22 to be separated from each other acts on the lower portions 40c of the side edge portions 24, 26. In addition, when the wearer of the diaper 10 actively moves his or her legs, a force possibly causing the front waist region 21 and the rear waist region 22 to be separated from each other acts on the lower portion 40c. The extra joint-spots 70 in the lower portion 40c of the flatly extended diaper 10b are used to avoid a separation of the front waist region 21 and the rear waist region 22 from each other possibly occurring in such an instance. In this regard, in order to prevent the extra joint-spots 70 from interfering with a desired separation of

2013-214234 the front and rear waist regions 21, 22 when it is desired to take off the diaper 10, an area of the individual extra joint-spot 70 and the number of the extra joint-spots 70 are preferably minimized. Compared to the diaper 10 obtained from the flatly extended diaper 10a, a junction area of the side edge portions 24 , 2 6 in the upper portion 40a and/or the lower portion 40c in the lateral seam 25 is larger than in the flatly extended diaper 10a and, in consequence, separation of the front waist region 21 and the rear waist region 22 becomes correspondingly difficult. However, even in such situation, it is possible to separate the front waist region 21 and the rear waist region 22 from each other in the intermediate portion 40b occupying at least 1/4 of the total length of the lateral seam 25 along the lateral seam 25 as smoothly as in the diaper 10 obtained from the flatly extended diaper 10a and mothers recognize this as the diaper which is easy-to-take off. If needed, the extra joint-spots 70 according to the present invention may be arranged in a column over the total length of the lateral seam 25. Further, according to the present invention, reinforcing joint-spots for a joint between the side edge portions 24, 26 may be formed outside the lateral seam 25 as viewed in the lateral direction B. Outside the lateral seam 25, such reinforcing joint-spots are preferably formed only in a very small area between the waist-opening 27 and a position 25 mm immediately

2013-214234 below from the waist-opening 27 and a very small area between the leg-openings 28 and a position 25 mm immediately above the leg-openings 28.

{ 0040 }

Fig. 7 is a partially cutaway diagram of a portion VII in Fig.

1, exemplarily illustrating an embodiment of the front panel 11 and the rear panel 12 which may be used by the present invention. The interior sheet 41 and the exterior sheet 42 in the front panel 11 are welded to each other in the lateral seam 25 and, in addition, bonded to each other by the hot melt adhesive 81. The hot melt adhesive 81 is distributed to the nearly whole surface of the interior sheet 41 or the exterior sheet 42. However, in the side edge portion 24 exemplarily illustrated, the hot melt adhesive 81 is distributed only to the portion of the interior sheet 41 or the exterior sheet 42 defined above the lowermost joint-spot 30b located at the lowest portion of the lateral seam 25. In consequence, below the joint-spot 30b, the interior sheet 41 and the exterior sheet 42 are in non-bonded state except at the joint-spot 30b. The term below the joint-spot 30b used herein means a range inclusive of the joint-spot 30b. Such arrangement is applicable also to the interior sheet 51 and the exterior sheet 52. Specifically, though the hot melt adhesive 81 is distributed to the nearly whole surface of the interior sheet 51 or the exterior sheet

2013-214234

52, in the side edge portion 26 of the rear waist panel 12, the hot melt adhesive 81 is distributed only to the portion of the interior sheet 51 or the exterior sheet 52 defined above the lowermost joint-spot 30b. Below the joint-spot 30b, the interior sheet 51 and the exterior sheet 52 are in non-bonded state except at the joint-spot 30b.

{ 0041 }

When the regions in which the hot melt adhesives 81, 82 are present are subjected to an ultrasonic process to form the joint-spots 30 at which the front panel 11 and the rear panel 12 are joined to each other, the hot melt adhesive 81 and/or the hot melt 82 may be softened or molten and deformed to enlarge the fiber-interstices (not shown) in the interior sheets 41, 51 and the exterior sheets 42, 52 and to leach out therethrough until holes may be left in these sheets 41, 42, 51, 52. Consequently, these sheets 41, 42, 51, 52 may tear easily and the diaper 10 and active movements of the wearer's legs may break the diaper 10 from the peripheries of the joint-spots 30b. Besides, when a caretaker tries to separate the front waist region 21 and the rear waist region 22 from each other starting from the leg-openings 28 toward the waist-opening 27 with the front waist region 21 and the rear waist region 22 in hands for the purpose of exchanging the diaper 10, the caretaker necessarily holds the diaper 10 upward and a manner of holding

2013-214234 may be altered slightly for every exchange of the diaper 10.

For this reason, a behavior of the force at a moment the front waist region 21 and the rear waist region 22 begin to be separated from each other may be different for each of the diapers 10 and may give the impression that there is a quality variation in the diapers 10 to the caretakers. However, as long as the diaper 10 is arranged like the illustrated embodiment according to which the hot-melt adhesives 81, 82 are used above the joint-spot 30b in the side edge portions 24, 26, it is possible to resolve the problem of giving such impression. In this regard, it is also possible for the diaper 10 to employ the illustrated arrangement in the front panel 11 and to employ the arrangement such that the hot melt adhesive 82 is present below the joint-spot 30b. Further, though not illustrated, it is possible to employ the arrangement similar to the exemplarily illustrated arrangement in the upper end portions of the side edge portions 24, 26. In this regard, in these upper end port ions, the hot melt adhesives 81, 82 are used below the joint-spot 30 in the upper end portion in the lateral seam 25.

{ 0042 }

Fig. 8 is a diagram illustrating steps (a), (b) and (c) of measuring a force needed to separate the front waist region 21 and the rear waist region 22 along the lateral seam 25 of the diaper 10 using a tensile tester 100 (see Fig. 8 (c)).

2013-214234 {0043}

Fig. 8 (a) indicates a collection position at which a measurement test piece 90 is collected from the diaper 10 of Fig. 1 under a tension at such a degree that gathers 31, 32 (see Fig. 1) formed under contraction of the elastic members 44, 54 (see Figs. 1 and 6) disappear. The diaper 10 having the front and rear waist regions 21, 22 overlapping with each other is cut out by scissors along guide lines 91 extending in parallel to the center line P. The guide lines 91 are distanced from the respective lateral seam 25 at least 30 mm.

{0044 }

Fig. 8 (b) indicates a state in which a portion of the front waist region 21 and a portion of the rear waist region 22 in the test piece 90 are held by an upper chuck 92 and a lower chuck 93, respectively, in the tensile tester 100. A distance dimension F between the chucks 92, 93 is set to 20 mm, the lateral seam 25 of the test piece is placed in the middle of the dimension F and respective portions 94 ranging 15 to 20 mm from respective upper edges 21a, 22a (see Fig. 1) of the front waist region 21 and the rear waist region 22 are held.

{0045}

Fig. 8 (c) is a photo indicating a behavior of the test piece 90 observed in elevating the upper chuck 92 at a rate of 500 mm/min relative to the fixed lower chuck 93. In the test piece

2013-214234

90, separation of the front waist region 21 and the rear waist region 22 from each other goes on along the lateral seam 25 as the chuck 92 rises.

{0046}

Fig. 9 (a) and Fig. 9 (b) are graphic diagrams exemplarily indicating the records of force needed for separation occurring in the test pieces 90 measured by the tensile tester 100. { 0047 }

Fig. 9 (a) indicates the record with respect to the diaper 10 having the lateral seam 25 as exemplarily indicated as EMBODIMENT 3 to be displayed hereinafter. The lateral seam 25 includes the circular joint-spots 30. The axis of abscissas indicates the elapse time per seconds when the front and rear waist regions are separated from each other along the lateral seam 25 from the upper portion 40a toward the lower portion 40c thereof and the axis of ordinates indicates the detected force per Ns. In this diagram, the detection result relating to four test pieces 90 obtained from two diapers 10 is indicated. According to the detection result, in the length range 15 to 20 mm held by the chucks 92, 93 of the test pieces 90, the peak value of force was 17 N or higher but, in the remaining region, the peak value was ranging 8 to 13 N without any remarkable variance occurring as the separation goes on. The regions held by the chucks 92, 93 corresponded to the upper portions 40a of

2013-214234 the respective lateral seam 25 and the remaining regions corresponded to the intermediate portions 40b and the lower portions 40c. In the diaper 10 having such lateral seam 25, separation of the front and rear waist regions 21, 22 was manually tried by pinching the tops of the front and rear waist regions 21, 22 across 15 mm, respectively, and it was found that a strong force is needed immediately after starting but thereafter the separation smoothly goes on merely by impressing a nearly uniform weak force.

{ 0048 }

In the diaper 10 provided for the measurement, as the material for the interior sheet 41 and the exterior sheet 42, the spun bond nonwoven fabrics having a mass per unit area of 15 g/m²formed of conjugate fibers having a fineness of 1.3 dtex and including polypropylene as a core component and polyethylene as a sheath component were used. The respective lateral seam 25 in the diaper 10 had a length in the vertical direction A was 126 mm.

{0049}

Fig. 9 (b) indicates the measurement result to be contrasted to Fig. 9 (a) and, as the diaper to be measured, a contrast diaper which is the same to the diaper 10 used in Fig. 9 (a) except that the contrast diaper has the seam region arranged in a manner different from the lateral seam 25. The seam region in the

2013-214234 contrast diaper is described above Fig. 9 (b). In this seam region, a number of parallelogram joint-spots slanted so as to define a descending slope in the lateral direction of the contrast diaper from the inside toward the outside were arranged in the vertical direction and the lateral direction.

{0050 }

In the light of the measurement result, a peak higher than 20 N appeared during an elapse time 0 to 4 seconds and thereafter the force drastically changed in a range 4 to 15 N. Using the diaper provided for the measurement indicated in Fig. 9 (b) , it was tried to separate the front and rear waist regions and it was found that a force needed for the separation is high from start to finish and drastically changes.

{0051} (Embodiment)

The inventors prepared an embodiment of the disposable pant-type diaper in which the entire length along the center line P in Fig. 2 is 470 mm, the vertical dimension in the side edge portions of the front waist region and the rear waist region is 130 mm and the length in the vertical direction of the lateral seam regions is 126 mm. As the material for the interior sheets and the exterior sheets in the front panel and the rear panel defining the front waist region and the rear waist region, respectively, spun bond nonwoven fabrics formed of conjugate fibers including polypropylene as a core component and

2013-214234 polyethylene as a sheath component so as to have a fineness of

1.3 dtex and a mass per unit area of 15 g/m³ were used. Strength in two directions orthogonal to each other of the nonwoven fabrics corresponding to the machine direction and the cross direction in production thereof was measured and the direction in which the strength is higher was brought in line with the lateral direction of the pant-type diaper. The interior sheet and the exterior sheet were bonded to each other by spirally spraying hot melt adhesives at a rate of 50 g/m². Between the interior sheet and the exterior sheet, a plurality of LYCRA (registered trademark) of 620 dtex were attached under tension at a stretching ratio of 2 and at intervals of 8 mm in the vertical direction. The joint-spots are formed in the side edge portions of the front and rear panels over the entire length thereof in the vertical direction wherein the shape, the size and the arrangement of the joint-spots were varied to produce the pant-type diapers as the embodiments and the pant-type diapers as the comparative examples distinguishable in the arrangement of the lateral seam region. Each of seven mothers as panelists put the five diapers as the embodiments and the five diapers as the comparative examples one by one on her infant (one year old), then took off the diaper by separating the front waist region and the rear waist region from each other with the upper ends of the respective side edge portions pinched by her fingers

2013-214234 and evaluation-scored as with respect to easiness (workability) of the separating operation as described below. An average value of the evaluation-scores by seven mothers was recorded as the workability of the evaluated pant-type diapers. The average value of the evaluation-scores given to the pant-type diapers according to the respective embodiments was 3 or higher and none of them was evaluated as the diaper inferior with respect to the workability.

(Workability)

Excellent

Good

Mediocre

Inferior

Very inferior {0052} (Evaluative score

Test pieces were cut out from the diapers as the embodiments and the diapers as the comparative examples to measure the joint strength in the lateral seam region. These test pieces were cut out from the upper portion or the intermediate portion (portions corresponding to the upper portion 40a or the intermediate portion 40b in Figs. 5 and 6) having the dimension of 25 mm in the vertical direction and the dimension of 40 mm in the lateral direction from the respective lateral seam regions in the front waist region and the rear waist region. A distance between the

2013-214234 chucks of the tensile tester (AUTOGRAPH AG-Xplus) was set to mm, the front waist region and the rear waist region were held by the chucks across 15 mm, respectively and the test piece was pulled at a pulling rate of 100 mm/min to measure a break strength (N/25mm) of the lateral seam region. An average value of the break strength measured on three test pieces was recorded as the strength of the lateral seam region. As the pant-type diapers used to evaluate the workability when the front waist region and the rear waist region are separated from each other, the diapers having the strength ranging 18 to 23 N/25 mm were used. The evaluation result indicated in Table 1 was obtained.

For the pant-type diapers having the lateral seam region having a dimension 3 mm or less in the lateral dimension B and the joint-spots are arranged in one or two columns in the lateral 15 seam region, an average evaluation score was 3 or higher.

2013-214234 { 0053} [TABLE 1] [ Tabale 1 ]

Comparative Example 3

co

CO

Parallelogram I

E E co LO ό X o cxi

0.64

Parallelogram 1.5 x0.53mm

0.83

LO ό

CO CXI

2.15

CO j O Z7L I mj mj m y

Comparative Example 2

LO xt

cxi

Parallelogram I

E E LO ό X iq

0.83

Parallelogram 1.5 x0.5mm

0.83

lo

CXI CXI

1.58

<Λ i’* <O T T JJ S B ΰ Sΰ 3 ΰ ή >.·> «> cS~x-“4f-_..-«: .. r-' ” “ O .

Comparative Example 1

co co

co

φ o o

diameter 0.8mm |

0.95

Circle diameter 0.8mm

0.95

CXI

§ S g 4 cJo 4; / fa ο ο ο ο ο ο ο ΐ iCDrO oju i 0 o o o o o o ofoooooooo)

Embodiments

iq

-

Parallelogram I

1.5x0.5mm |

1.33

o CXI

to CO

» | --X <17 £$ 3 M 3 8 3 3$ & t*> iq

Embodiment4

-

Φ CJ O

diameter 1,0mm |

10 ό

co cxi

3.38

£X|POOOOC^ |)00000000^ cri

Embodiments

-

Φ o ό

diameter 1,2mm |

OO

o Cxi

XT

L..O p Ο Ο Ο Ο O «h*· cq

Embodiments

xr cxi

-

Φ o o

diameter 1,0mm |

(XJ co

Circle diameter 1,0mm

-

(XJ co

xr ό

CM

3.88

CM co xt 1........0 O ) j Ο O o] Cxi co

Embodiment 1

co cxi

-

Φ o ό

I diameter 0.8mm |

1.85

Circle diameter 0.8mm

-

1.86

CXI

cxi CXI

co

b d β ο ο ο o ] p o ( ( p oo o o( cp-

Arrangement of lateral seam

Dimension in lateral direction of lateral seam (mm)

# column ofjoint-spots

Shape ofjoint-spots

Distance dimension in vertical direction ofjoint-spots

Extra joint-spots column

Shape of extra joint-spots

# column of extra joint-spots

Distance dimension in vertical direction of extra joint-spots

Distance dimension in lateral direction between joint-spots oolum and extra joint-spots colum (mm)

Strength of lateral seam (N/25mm)

Workability of lateral seam (Evaluative Score)

Shape and Distribution ofjoint-spots in lateral seam

2013-214234 {0054 }

The present invention described here on the basis of the disposable diaper for infant may be embodied in the form of wearing articles such as pant-type diaper for adult, pant for incontinent and training-pant.

{0055}

The disclosure relating to the present invention described above may be arranged at least as follows:

{0056}

A disposable pant-type wearing article including sheets to define a front waist region and a rear waist region, each having a vertical direction and a lateral direction, respective side edge portions of the sheets being welded together at a plurality of joint-spots arranged in the vertical direction so as to define a pair of lateral seam regions extending in the vertical direction and opposed to each other, wherein:

the respective sheets defining the front waist region and the rear waist region are at least two sheets of nonwoven fabrics made of thermoplastic synthetic fibers having a fineness ranging 0.1 to 4 dtex and a mass per unit area ranging 7 to 25 g/m² and, in at least one of the at least two sheets of nonwoven fabrics, a tensile strength in the vertical direction is lower than a tensile strength in the lateral direction;

a dimension in the lateral direction of the lateral seam

2013-214234 region is 3 mm or less; and each of the joint-spots in the lateral seam region has a dimension in the vertical direction of 1.5 mm or less, the innermost end portions of the respective joint-spots are in contact with an imaginary line rectilinearly extending in the vertical direction so as to define a column extending in the vertical direction and, in the column, the minimum interval between a pair of the joint-spots adjacent in the vertical direction is ranging 0.4 to 5 mm.

{0057}

The present invention summarized above may include embodiments at least as described below and these embodiments may be taken in isolation or in combination.

(1) In the lateral seam region, the joint-spots define, in addition to the column described above, an additional column.

(2) The joint-spot has a dimension in the lateral direction of 3 mm or less.

(3) The pant-type wearing article has a crotch region joined to the front waist region and the rear waist region, these front waist region, the rear waist region and the crotch region cooperate together to form leg-openings on opposite sides of the pant-type wearing article wherein the lateral seam regions extend between the waist-opening and the leg-openings and, on the outer side in the lateral direction of the lateral seam

2013-214234 regions, extra joint-spots are formed in addition to the joint-spots in at least one of an upper portion having a length ranging 1/10 to 1/2 of the length of the lateral seam region and located immediately below the waist-opening and a lower portion having a length ranging 1/10 to 1/2 of the length of the lateral seam region and located immediately above the leg-openings .

(4) The sheet has cut ends on opposite sides thereof and the lateral seam regions are formed in a range 4 to 13 mm from the respective cut ends toward the inner side of the pant-type wearing article.

(5) Seam-free regions including none of the joint-spots are formed on the outer sides in the lateral direction of the lateral seam regions and a dimension of the seam-free region corresponding to a dimension between the seam-free region and the cut end is larger than a dimension in the lateral direction of the seam region.

(6) The front waist region and the rear waist region include a plurality of elastic members extending under tension in a waist-surrounding direction and the cut end of the sheet defining the front waist region and the cut end of the sheet defining the rear waist region are welded to each other and wherein a sleeve-like bulge extending in the vertical direction is formed between the cut end and the lateral seam region under

2013-214234 contraction of the elastic members.

(7) At least two sheets of the nonwoven fabric in at least one of the front waist region and the rear waist region have no hot melt adhesives distributed therebetween and thereby are in a non-joined state at least one of the portion defined above the uppermost joint-spot in the lateral region and the portion defined below the lowermost joint-spot in the lateral seam region .

(8) With respect to a force needed to separate the front waist region and the rear waist region starting from the upper end toward the lower end of the seam region, a peak value of the force needed in an upper portion defined by a range of 25 mm from the upper end is at least 17 N and a peak value of the force needed in a lower portion defined from below the upper portion to the lower end is in a range 8 to 13 N.

{Reference Signs List} {0058} disposable pant-type wearing article (pant-type diaper) front waist region rear waist region crotch region side edge portions lateral seam side edge portions

2013-214234 waist-opening leg-openings seam-free region

30, 30b joint-spots inner end portion imaginary line (straight line) columns of joint-spots

40a upper portion

40c lower portion sheet (interior sheet) sheet (exterior sheet) cut ends elastic members puff sheet (interior sheet) sheet (exterior sheet) cut ends elastic members extra joint-spots

A vertical direction

B lateral direction

M dimension

W dimension

Claims

The claims defining the invention are as follows:

{Claim 1}

A disposable pant-type wearing article including sheets
5 to define a front waist region and a rear waist region, each having a vertical direction and a lateral direction, respective side edge portions of the sheets being fixed together at a plurality of joint-spots arranged in the vertical direction so as to define a pair of lateral seam
10 regions extending in the vertical direction and opposed to each other, wherein:

the respective sheets defining the front waist region and the rear waist region are at least two sheets of nonwoven fabric made of thermoplastic synthetic fibers 15 having a fineness ranging 0.1 to 4 dtex and a mass per unit area ranging 7 to 25 g/m² and, in at least one of the at least two sheets of nonwoven fabrics, a tensile strength in the vertical direction is lower than a tensile strength in the lateral direction;

20 a dimension in the lateral direction of the lateral seam region is 3 mm or less; and each of the joint-spots in the lateral seam region has a dimension in the vertical direction of 1.5 mm or less, the innermost end portions of the respective joint-spots are in

2014332820 30 Apr 2019 contact with an imaginary line rectilinearly extending in the vertical direction so as to define a column extending in the vertical direction and, in the column, the minimum interval between a pair of the joint-spots adjacent in the 5 vertical direction is in a range 0.4 to 5 mm;

the sheets have cut ends on opposite sides thereof and are fixed to each other in the cut ends;

seam-free regions not joining the side edges to each other are formed between the lateral seam region and the 10 cut end in the lateral direction;

a plurality of elastic members extending in a waistsurrounding direction is located between the two sheets of the nonwoven fabrics in the front waist region and the rear waist region; and
15 a sleeve-like bulge extending in the vertical direction is formed in the seam-free region under contraction of a plurality of the elastic members extending in the lateral direction .

{Claim 2}
20 The pant-type wearing article according to Claim 1 wherein the joint-spot has a dimension in the lateral direction of 3 mm or less.

{Claim 3}

The pant-type wearing article according to Claim 1 or 2

2014332820 30 Apr 2019 wherein the pant-type wearing article has a crotch region joined to the front waist region and the rear waist region, the front waist region, the rear waist region and the crotch region cooperate together to form leg-openings on 5 opposite sides of the pant-type wearing article and wherein the lateral seam regions extend between the waist-opening and the leg-openings and, on the outer side in the lateral direction of the lateral seam regions, extra joint-spots are formed in addition to the joint-spots in an upper 10 portion having a length ranging 1/10 to 1/2 of the length of the lateral seam region and located immediately below the waist-opening and a lower portion having a length ranging 1/10 to 1/2 of the length of the lateral seam region and located immediately above the leg-openings.

15 {Claim 4}

The pant-type wearing article according to any one of Claims 1 through 3 wherein the joint-spot has a dimension in the lateral direction larger than a dimension in the vertical direction.

20 {Claim 5}

The wearing article according to any one of Claims 1 through 4 wherein two sheets of the nonwoven fabrics in the front waist region and the rear waist region have no hot melt adhesives distributed therebetween and thereby are in

2014332820 30 Apr 2019 a non-joined state at the portion defined below the lowermost joint-spot in the lateral seam region.

{Claim 6}

The pant-type wearing article according to any one of

5 Claims 1 through 5 wherein, with respect to a force needed to separate the front waist region and the rear waist region starting from the upper end toward the lower end of the seam region, a peak value of the force needed in an upper portion defined by a range of 25 mm from the upper 10 end is at least 17 N and a peak value of the force needed in a lower portion defined from below the upper portion to the lower end is in a range 8 to 13 N.