WO2013190831A1

WO2013190831A1 - Wearing article

Info

Publication number: WO2013190831A1
Application number: PCT/JP2013/003793
Authority: WO
Inventors: Takahito Nagai; Tomoko Tsuji; Nobuhiro Tagawa
Original assignee: Unicharm Corporation
Priority date: 2012-06-19
Filing date: 2013-06-18
Publication date: 2013-12-27
Also published as: CN104379106A; JP2014000275A; CN104379106B; JP5901440B2

Abstract

A wearing article (1) has a mechanical fastener for connecting a front waist region (2) and a rear waist region (3) to each other. The mechanical fastener has a hook element and a loop element, and the loop element is formed of a nonwoven fabric forming an exterior layer (42) of the wearing article (1). The nonwoven fabric has non-weld regions (55) each surrounded by a pair of first weld lines (51) and a pair of second weld lines (52) wherein at least a portion of a third weld portion (53a) is present in the non-weld region (55).

Description

WEARING ARTICLE

The present disclosure relates to wearing articles.

Background

Disposable diapers or disposable diaper covers are known to utilize mechanical fasteners so that a front waist region and a rear waist region may be repetitively connected to and disconnected from each other. Such mechanical fasteners include hook elements and loop elements adapted to cooperate with the hook elements.

For example, a nonwoven fabric used as material for a planar fastener disclosed in JP 1997-241961 A (PTL 1) is formed of continuous fibers and has partially thermocompression bonded regions. The continuous fibers forms folded loops in non-thermocompression bonded regions defined between the adjacent thermocompression bonded regions. Within each of the folded loops, at least two smaller folds are present. As the continuous fibers, eccentric core-in-sheath type fibers of which latent crimps have been actuated are used. This specific nonwoven fabric is used as material for the planar fastener to solve a problem that the diaper cover might be displaced or unengaged during use thereof, for example, when a fabric merely forming loops is used as the planar fastener in the diaper cover.

A disposable diaper disclosed in JP 1999-335960 A (PTL 2) uses the male element of the mechanical fastener and the female element formed of a nonwoven fabric adapted to be engaged with this male element. This nonwoven fabric is an air-through nonwoven fabric formed with an emboss-pattern so as to cross with a machine direction (MD direction) of the nonwoven fabric. One example of the emboss-pattern is a grid-like pattern composed of emboss lines extending in parallel to a CD direction and emboss lines extending in parallel to the MD direction. In another example of the grid-like emboss pattern, the emboss lines obliquely intersect with the MD direction.

JP 2003-38213 A (PTL 3) discloses a continuous fiber nonwoven fabric having loops which may be repetitively engaged to hook members of a planar fastener sometimes designated as a mechanical fastener. In this nonwoven fabric, the continuous fibers forming this nonwoven fabric are joined together at partially thermocompression bonded regions which are discontinuously scattered and also in thermocompression bonded regions in the form of generally continuous parallel lines.

JP 1997-241961 A JP 1999-335960 A JP 2003-38213 A

Summary

In disposable diapers having an exterior layer formed of the nonwoven fabrics of thermoplastic synthetic fibers there may be formed emboss/deboss lines and/or thermocompression bonded regions to use such a nonwoven fabric as the loop element adapted to cooperate with the hook element of the mechanical fastener. The emboss lines and the thermocompression bonded regions serve to improve an upper limit of a tensile shear strength that may act between the nonwoven fabric and the hook element and/or to alleviate a fuzzing phenomenon. However, the inventor(s) has noted that, in wearing articles such as a disposable diaper, if a nonwoven fabric is used as the member which is cooperative with a hook element to connect the front waist region and the rear waist region to each other and to tighten the article circumferentially about the wearer's waist, there is a likelihood that either the nonwoven fabric or the hook element might be circumferentially displaced about the wearer's waist from the initial tightened position and, in consequence, a tightening effect might be decreased.

In some embodiments, a wearing article having a longitudinal direction includes a front waist region, a rear waist region and a crotch region interposed between these two regions, an interior surface for facing a wearer's skin, an exterior surface for facing away from the wearer's skin, and a mechanical fastener for connecting the front waist region and the rear waist region to each other.

The mechanical fastener includes a hook element and a loop element adapted to cooperate with the hook element. The hook element is attached to one of the front and rear waist regions. The loop element is formed of a nonwoven fabric of thermoplastic synthetic fibers forming at least part of the exterior surface in at least another waist region. The nonwoven fabric has welded regions formed by the thermoplastic synthetic fibers molten and integrally solidified. The weld regions include a plurality of first weld lines extending in parallel to each other in a first direction, a plurality of second weld lines extending in parallel to each other in a second direction intersecting with the first direction, and a plurality of third weld lines including rows of third weld portions arranged at intervals in a third direction intersecting with the first and second directions. The nonwoven fabric further has non-weld regions each having a shape of a parallelogram surrounded by one pair of the adjacent first weld lines and one pair of the adjacent second weld lines. At least a portion of at least one of the third weld portions is present within the non-weld region.
In some embodiments, a wearing article having a longitudinal direction includes a front waist region, a rear waist region, and a crotch region interposed between the front waist and rear waist regions. An interior surface of the article is configured to face a wearer's skin, and an exterior surface of the article is configured to face away from the wearer's skin. The article has a mechanical fastener for connecting the front waist region and the rear waist region. The mechanical fastener includes a hook element and a loop element configured to be engaged with the hook element. The hook element is attached to one of the front and rear waist regions and the loop element is formed of a nonwoven fabric of thermoplastic synthetic fibers forming at least part of the exterior surface in the other waist region. The nonwoven fabric has weld regions formed of the thermoplastic synthetic fibers molten and integrally solidified. The weld regions include a plurality of weld lines intersecting each other, and a plurality of weld portions. The nonwoven fabric further has non-weld regions each surrounded by one or more of the weld lines. At least a portion of at least one of the weld portions is present within the non-weld region.

Fig. 1 is a partially cutaway plan view illustrating an interior surface of a disposable diaper as an example of wearing articles. Fig. 2 is a partially cutaway plan view illustrating an exterior surface of the diaper illustrated in Fig. 1. Fig. 3 is a scale-enlarged diagram illustrating a portion III in Fig. 2. Fig. 4 is a scale-enlarged diagram illustrating a portion of Fig. 3. Fig. 5 is a diagram illustrating an example in accordance with some embodiments. Fig. 6 is a diagram illustrating another example in accordance with some embodiments. Fig. 7 is a diagram illustrating still another example in accordance with some embodiments.

Taking a disposable diaper as an example, details of a wearing article according to some embodiments of the present invention will be described hereunder.

Referring to Fig. 1 illustrating an interior surface 1a of a disposable diaper 1, the interior surface 1a faces a wearer's skin (not shown) when the diaper 1 is in use. The diaper 1 has a longitudinal direction A in parallel to a longitudinal axis P-P and a transverse direction B being orthogonal to the longitudinal axis P-P and is configured symmetrically about the longitudinal axis P-P bisecting a dimension in the transverse direction B of the diaper 1. The diaper 1 includes, as viewed in the longitudinal direction A, a front waist region 2, a rear waist region 3 and a crotch region 4 lying between these two waist regions 2, 3. The diaper 1 includes, in its midsection in the transverse direction B, with a chassis 6 extending in the longitudinal direction A. The chassis 6 has a pair of lateral edge portions 11 extending in the longitudinal direction A and front and rear

end edge portions

12, 13 extending in the transverse direction B. As shown, it is preferable that a pair of front wings 14 extend outwardly in the transverse direction B from the front waist region 2 in the chassis 6 and a pair of rear wings 16 extend outwardly in the transverse direction B from the rear waist region 3 in the chassis 6. Connecting tape tabs 21 to be used when the diaper 1 is put on the wearer's body may be attached onto the respective rear wings 16 at respective lateral edge portions 17 thereof. Both the front wings 14 and the rear wings 16 may be formed of various kinds of materials, for example, a nonwoven fabric, a plastic film, a laminate sheet of a nonwoven fabric and a plastic film, or a laminate sheet of a nonwoven fabric, a plastic film and a nonwoven fabric.

Each of the tape tabs 21 has a proximal portion 22 attached to the rear wing 16 and a connecting distal portion 23 adapted to be extensible outwardly in the transverse direction B from the lateral edge portion 17. The connecting distal portion 23 has a hook element of the mechanical fastener type known under the trademark of "Velcro" attached to an interior surface of the connecting distal portion 23. In the tape tab 21, the connecting distal portion 23 is folded onto the interior surface of the rear wing 16 and releasably engaged therewith. The tape tabs 21 may be formed of, for example, a plastic film, a nonwoven fabric or a laminate sheet of a plastic film and a nonwoven fabric.

The chassis 6 has a liquid-permeable bodyside liner 32 defining the interior surface 1a, a liquid-impermeable leakage-barrier layer 33 and an absorbent structure 34 interposed between these liner 32 and layer 33. The bodyside liner 32 and the leakage-barrier layer 33 overlap with each other and are preferably joined to each other along respective extended portions of these liner 32 and layer 33 extending outwardly beyond the periphery of the absorbent structure 34 with a hot melt adhesive (not shown). Between the bodyside liner 32 and the leakage-barrier layer 33 overlapping with each other, leg elastics 36 extending in the longitudinal direction A, and front and

rear waist elastics

37, 38 are preferably interposed and these

elastics

36, 37, 38 when disposed, as shown, are secured under tension to at least one of the bodyside liner 32 and the leakage-barrier layer 33. The absorbent structure 34 is formed of water-absorbent materials 39 such as fluff wood pulp or superabsorbent polymer particles wrapped with a liquid-permeable wrapping sheet 41. The superabsorbent polymer particles used herein may be those commonly used in the related technical field, for example, the particles formed of a hydrolysate of starch-acrylonitrile-copolymer.

The bodyside liner 32 may be formed of a liquid-permeable nonwoven fabric made of thermoplastic synthetic fibers having been treated to become hydrophilic or a perforated plastic film. The leakage-barrier layer 33 may be formed of a low-liquid-permeable, liquid-impermeable nonwoven fabric of thermoplastic synthetic fibers, a liquid-impermeable or breathable, liquid-impermeable plastic film, or a laminate thereof.

Referring to Fig. 2 illustrating an exterior surface 1b of the diaper 1, this exterior surface 1b faces a wearer's garment (i.e., faces away from the wearer's skin) when the diaper 1 is in use. An exterior layer 42 defining the exterior surface of the chassis 6 is an assembly of thermoplastic synthetic fibers, for example, a fiber assembly in the form of a nonwoven fabric and joined to the leakage-barrier layer 33 interposed between the exterior layer 42 and the absorbent structure 34 with a hot melt adhesive (not shown), for example. The exterior layer 42 provides the exterior surface of the diaper 1 with a cloth-like soft texture and functions as a loop element which engages with the hook elements 24 on the respective connecting tape tabs 21.

Referring to Fig. 3 illustrating a portion III in Fig. 2, the exterior layer 42 has a first direction E indicated by a straight line obliquely extending from bottom right to top left across the longitudinal direction A and a second direction F indicated by a straight line obliquely extending from bottom left to top right across the longitudinal direction A. In some embodiments, the first and second directions are not perpendicular to each other. The exterior layer 42 is formed with a plurality of first weld lines 51 rectilinearly extending in parallel to and spaced apart from each other in the first direction E, along the first weld lines 51 the thermoplastic synthetic fibers 50 in the exterior layer 42 are welded together, and similarly, a plurality of second weld lines 52 rectilinearly extending in parallel to and spaced apart from each other the second direction F. Along the second weld lines, the thermoplastic synthetic fibers 50 are welded together in the same manner as the first weld lines 51. Each pair of the adjacent first weld lines 51 and each pair of the adjacent second weld lines 52 intersect each other to define a plurality of non-weld regions 55 surrounded by these two pairs of the adjacent weld lines 51, 52. Each planar shape of the non-weld region 55 is a parallelogram having a pair of first corners 55a opposed to each other in the longitudinal direction A and a pair of second corners 55b opposed to each other in the transverse direction B. As used herein, the term "parallelogram" is inclusive of a square and a rectangle. In an example, a length of each side Q₁, Q₂ (along the corresponding first and second directions E and F) is in a range of 3 to 10 mm, and a distance D₁, D₂ (in directions perpendicular to the corresponding first and second directions E and F) between each pair of the sides extending in parallel to each other and opposed to each other is at least 2 mm. In some embodiments, the non-weld regions have a shape other than the parallelogram shape, and/or the weld lines are not necessarily linear and/or arranged along only two directions, provided that the weld lines intersect each other to surround the non-weld regions.

The exterior layer 42 is further formed with third weld portions 53a. In the weld portions 53a, the thermoplastic synthetic fibers 50 in the fiber assembly of the exterior layer 42 are welded together in the same manner as the first and second weld lines 51, 52. In some embodiments, the thermoplastic synthetic fibers 50 in one or more of the first and second weld lines 51, 52 and the weld portions 53a are not only welded together but also depressed. These third weld portions 53a lie in a third direction G and are arranged at intervals in the third direction G intersecting with the first direction E and the second direction F so as to define third weld lines 53. The weld lines 53 are arranged adjacent to each other in a direction which is orthogonal to the third direction G. In an exemplified embodiment, the third direction G corresponds to the transverse direction B and the direction which is orthogonal to the third direction G corresponds to the longitudinal direction A. The third weld portions 53a formed in this manner may be arranged so that only one third weld portion 53a is present in every non-weld region 55 or a portion of only one third weld portion 53a is present in every non-weld region 55. In some embodiments, the third weld portion 53a is arranged so as to intersect with a diagonal 56a extending between a pair of the first corners 55a and to overlap with a diagonal 56b extending between a pair of the second corners 55b. It should be noted that the first, second and third directions need not be limited as discussed above. For example, the first direction could be the transverse direction with the second direction the longitudinal direction and the third direction may be altered as discussed below in the discussion of Figure 4. The pattern of weld lines could be rotated or otherwise modified, as will be readily appreciated by those skilled in the art.

The fiber assembly from which the exterior layer 42 is formed is a filament- or staple-assembly of thermoplastic synthetic fibers 50 (See Fig. 4) having a fineness in a range of 1 to 3 dtex. When using the staple-assembly, a length of filament is at least twice a length of the longest side, for example, twice a length of the longest side and 50 mm or longer. The fiber assembly has a mass per unit area in a range of 15 to 40 g/m². The fiber assembly is formed with the first and second weld lines 51, 52 and/or the third weld portions 53a and whereby the fibers 50 (See Fig. 4) are welded together to have the form of a nonwoven fabric. In this regard, it is also possible to use, instead of the above-mentioned fiber assembly, a nonwoven fabric such as a thermal bonded nonwoven fabric formed with the first and second weld lines 51, 52 and the third weld portions 53a.

These first and second weld lines 51, 52 and the third weld portions 53a on the exterior layer 42 are obtained by locally embossing/debossing a web of the fiber assembly for the exterior layer 42, continuously fed in one direction (e.g., the MD direction) by passing the web through a pair of embossing/debossing rolls in which at least one of the paired rolls is used in a state of being heated up to a melting temperature at which the thermoplastic synthetic fibers 50 are molten. The at least one heated roll has on a peripheral surface thereof, an arrangement of pins or bosses corresponding to an arrangement of the first, second and third weld lines 51, 52, 53. In the first and second weld lines 51, 52 and the third weld portions 53a obtained in this manner, the thermoplastic synthetic fibers 50, upon contact with the pins or bosses of the at least one heated roll, are welded together so that the welded thermoplastic synthetic fibers 50 are not separated from one another to move freely. While the web worked by the emboss/deboss rolls is sometimes formed on one of opposite surfaces in the portions corresponding to the first and second weld lines 51, 52 and the third weld portions 53a with groove-like depressions or sometimes formed on both surfaces in these portions with the groove-like depressions, in any of these two cases, these depressions can be used as the first and second weld lines 51, 52 and the third weld portions 53a so long as these groove-like depressions are concave from the exterior surface toward the interior surface 1a of the diaper 1. The first and second weld lines 51, 52 and the third weld portions 53a facilitate the hook element 24 and the non-weld regions 55 to be engaged to each other.

For the thermoplastic synthetic fibers 50 in the non-weld regions 55 of the exterior layer 42, assuming that the thermoplastic synthetic fibers 50 are filaments, at least two locations thereof as viewed in the length direction immovably lie in one of the first and second weld lines 51, 52 and the third weld portion 53a, and define opposite ends in the non-weld region 55. A portion extending between the opposite ends of the fibers 50 is not rectilinear strained but left to form an arch or a meander shape so that the hooks (not shown) of the hook element may be smoothly engaged therewith and reliably engaged.

When putting on the diaper 1, the connecting tape tabs 21 are circumferentially pulled about the wearer's waist and pressed against the exterior layer 42 in the front waist region 2 so that the hooks of the hook elements 24 are detachably engaged to the thermoplastic synthetic fibers 50 in the non-weld region 55 of the exterior layer 42, thereby connecting the front waist region 2 and the rear waist region 3 with each other in a state of tension. Upon connection, the front waist region 2 and the respective connecting tape tabs 21 apt to move away from each other in opposite directions, whereby a shear force is developed between the both

sides

2, 21. At this moment, those of the thermoplastic synthetic fibers 50 in the non-weld regions to which the hook elements 24 have been engaged are pulled in a direction in which the connecting tape tabs 21 tend to move and deformed so as to become in a state of tension (See Fig. 4). Such deformation of the thermoplastic synthetic fibers 50 would otherwise allow the connecting tape tabs 21 to be displaced from the initial positions thereof in the front waist region 2 toward the dorsal side and release the front waist region 2 and the rear waist region 3 in the state of tension. However, in the diaper 1 according to some embodiments of the present invention, as will be described later with reference to Fig. 4, each of the non-weld regions 55 is formed with the third weld portion 53a adapted to inhibit, in a middle portion of the diagonal 56a extending in the longitudinal direction A, movements of the thermoplastic synthetic fibers 50 extending in parallel to the diagonal 56a.

Fig. 4 illustrates one of the non-weld regions 55 in Fig. 3. In each of the non-weld regions 55, the thermoplastic synthetic fiber 50 extending approximately in parallel to the diagonal 56a is welded together with the coexisting thermoplastic synthetic fibers (not shown) on the first and second weld lines 51, 52 and the third weld portion 53a and, in consequence, movements of the fibers 50 welded together is inhibited. In Fig. 4, regions in which the thermoplastic synthetic fibers 50 are welded together in this manner are indicated by

reference signs

50a, 50b and 50c. The thermoplastic synthetic fibers 50 are divided into an upper portion 61 extending from the second weld line 52 to the third weld portion 53a and a lower portion 62 extending from the third weld portion 53a to the first weld line 51. These upper and

lower portions

61, 62 are deformed as indicated by chain lines when the connecting tape tab 21 pulls these upper and

lower portions

61, 62 rightward in the transverse direction B as indicated by arrows N₁, N₂ and the connecting tape tab 21 also may slightly be moved rightward. In contrast, the thermoplastic synthetic fibers 50 indicated by a chain double-dashed line is on the assumption that the non-weld region 55 is not formed with the third weld portion 53a and movements of the thermoplastic synthetic fibers 50 is inhibited only in

regions

50d, 50e on the first weld line 51 and the second weld line 52, respectively. In this case, when the connecting tape tab 21 pulls the thermoplastic synthetic fibers 50 rightward in the transverse direction B as indicated by an arrow N₃, the thermoplastic synthetic fibers 50 as a whole are deformed so as to be convex rightward and the connecting tape tab 21 also significantly moves rightward as viewed in Fig. 4. While the connecting tape tab 21 is adapted to be detachably engaged to a plurality of the thermoplastic synthetic fibers 50 in the exterior layer 42, one of the causes for displacement of the connecting tape tab 21 rightward as viewed in Fig. 4 will be sufficiently understood from the description of a single thermoplastic synthetic fibers 50 in Fig. 4.

The third weld portion 53a functioning in a manner as has been described above is elongated (or extends), in accordance with some embodiments, not in the longitudinal direction A but in the transverse direction B. However, in at least one embodiment, it is not essential for the third weld portion 53a to extend horizontally in parallel to the transverse direction B. The third weld portion 53a may, for example, extend at an angle of slope of 20^oor less relative to the transverse direction B. When a web including a filament assembly of the thermoplastic synthetic fibers 50 is continuously produced with use of an extruder, a plurality of the thermoplastic synthetic fibers 50 tend to extend in the machine direction. In the course of being continuously fed in the machine direction, the web may be locally pressed by the heated embossing/debossing rolls to form the first and second weld lines 51, 52 and the third weld portions 53a. In this course of formation of these lines and portions, the third weld portions 53a are formed, in at least one embodiment, to extend in the cross direction which is orthogonal to the machine direction, in other words, extend in the transverse direction B in the exterior layer 42 obtained from the web.

Referring again to Figs. 3 and 4, the first and second weld lines 51, 52 and the third weld portion 53a are, in at least one embodiment, free from adversely affecting a flexibility of the exterior layer 2. To ensure this, a particular example includes the following relationships. Specifically, the first and second weld lines 51, 52 have, in at least one embodiment, respective width dimensions W₁, W₂ in a range of 0.2 to 2 mm and not exceeding 2 mm. Distances D₁, D₂ between a pair of the adjacent first weld lines 51 and between a pair of the adjacent second weld lines 52, respectively, defined by distance spaces between parallel sides of the respective pairs of the adjacent first weld lines 51 and the adjacent second weld lines 52 are preferably in a range of 3 to 10 mm. The third weld portions 53a preferably have a dimension W₃ in the longitudinal direction A in a range of 0.2 to 5 mm, a dimension L₃ in the transverse direction B in a range of 2.5 to 10 mm and larger than the dimension W₃. Dimensions Q₁, Q₂ of respective sides in the non-weld region 55 are preferably at least 2 mm. On the third weld lines 53 defined by a row of the third weld portions 53a, a distance dimension J₃ between each pair of the adjacent third weld portions 53a in the third direction G is preferably in a range of 3 to 10 mm, and a distance dimension K₃ between each pair of the adjacent third weld lines 53 in a direction orthogonal to the third direction G is also preferable in a range of 2 to 10 mm.

Fig. 5 illustrates one example in accordance with in at least one embodiment. The first and second weld lines 51, 52 in the exterior layer 42 illustrated in Fig. 5 are different from those in Fig. 3 in that the first weld line 51 is formed of a plurality of first weld portions 51a arranged at intervals in the first direction E and the second weld line 52 is formed of a plurality of second weld portions 52a arranged at intervals in the second direction F. The first weld portion 51a and the second weld portion 52a preferably have respective dimensions L₁, L₂ in a range of 1 to 5 mm and respective width dimensions W₁, W₂ in a range of 0.2 to 2 mm. Distance dimensions J₁, J₂ between each pair of the adjacent first weld portions 51a and between each pair of the adjacent second weld portions 52a are preferably in a range of 0.2 to 2 mm. The third weld portions 53a are formed in the same manner as the third weld portion 53a in Fig. 3. The arrangement of the first and second weld lines 51, 52 illustrated in Fig. 5 may improve the flexibility as well as the texture of the exterior layer 42 in comparison to the exterior layer 42 illustrated in Fig. 3. In the exterior layer 42, it is possible to form either the first weld lines 51 or the second fold lines 52 to be continuous and rectilinear in the same manner as exemplified in Fig. 3 (in which at least one of the weld lines 51, 52 is formed of a single weld portion extending continuously along multiple non-weld regions 55).

Fig. 6 illustrates another example in accordance with in at least one embodiment. Locations of the respective third weld portions 53a in the respective non-weld regions 55 are not limited in any of the embodiments described herein to those as illustrated in Fig. 3 (in which the weld portions 53a do not intersect the weld lines 51, 52) and the third weld portions 53a may be located to intersect with the second weld lines 52 as in Fig. 6 and/or to intersect with the first weld lines 51.

Fig. 7 illustrates still another example in accordance with in at least one embodiment. In the exterior layer 42 illustrated in Fig. 7, each of the first weld lines 51 is formed from two rows of a plurality of first weld portions 51a and each of the second weld lines 52 is formed from two rows of a plurality of second weld portions 52a. In each of the rows of the first weld lines 51 extending in the first direction E, the dimension L₁ of the first weld portion 51a and the distance dimension J₁ between each pair of the adjacent first weld portions 51a are in the same ranges, respectively, as the dimensions L₁ and J₁ in Fig. 5. A width dimension w₁ of the first weld portion 51a is preferably in a range of 0.2 to 0.8 mm and a distance dimension M₁ between the laterally adjacent first weld portions 51a in each pair of the adjacent rows is preferably in a range of 0.4 to 1.6 mm. A width dimension W₁ of the first weld line 51 including two rows of the first weld portions 51a is preferably 2 mm or less. As for the second weld portion 52a in the second weld line 52, values of a dimension L₂, a distance dimension J₂, a width dimension w₂ and a distance dimension M₂ are in the same ranges as the values of the dimension L₁, the distance dimension J₁, the width dimension w₂ and the distance dimension M₁ for the first weld portion 51a. A width dimension W₂ of the second weld line 52 including two rows of the second weld portions 52a is preferably 2 mm or less. According to at least one embodiment, the first weld line 51 and the second weld line 52 respectively have the width dimensions W₁, W₂ of 2 mm or less and may include a plurality of fine weld lines or a plurality of rows of fine third weld portions. In each of the two rows forming the first weld line 51, the position and/or length may be adjusted so that the spaces S₁ between the adjacent first weld portions 51a having the distance dimension J₁ in the adjacent rows of the first weld portions 51a are not aligned with each other in a direction orthogonal to the first direction E. Additionally or alternatively, this is true also for the two adjacent rows of the second weld portions 52a forming the second weld line 52. Specifically, the position and/or length of the second weld portions 52a may be adjusted so that the spaces S₂ between the adjacent second weld portions 52a in the adjacent rows of the second weld portions 52a are not aligned with each other in a direction orthogonal to the second direction F.

As illustrated in Fig. 7, when the first and second weld lines 51, 52 surrounding the non-weld region 55 are formed of a plurality of rows of the weld lines having relatively narrow width dimensions and extending in parallel to each other and each row is formed of the first or second weld portions arranged at intervals, flexibility of the exterior layer 42 may be improved in comparison to the case in which the first and second weld lines 51, 52 have relatively large width dimension. In addition, when the spaces S₁or spaces S₂ are not aligned with each other between the two rows adjacent to each other and extending in parallel to each other, movement of the thermoplastic synthetic fibers extending between the adjacent non-weld regions 55 in the exterior layer 42 may be reliably inhibited by the first weld lines 51 and the second weld lines 52 and whereby displacement of the connecting tape tabs 21 engaged to the non-weld regions 55 from the ventral side to the dorsal side of the wearer may be inhibited.

With the arrangements of the exterior layer 42 illustrated in Figs. 3 through 7, the connecting tape tabs 21 may be engaged to the exterior layer 42 in any location and consequently even when a size of the diaper 1 is not appropriate for the wearer, the diaper 1 may be easily adjusted to fit about the wearer's waist.

In some embodiments, it is not essential for the exterior layer 42 functioning as one member of the mechanical fastener to be disposed in the entire chassis and, for example, the exterior layer 42 may be used only in the front waist region 2 of the chassis 6. When the connecting tape tabs 21 are attached to the front waist region 2, the exterior layer 42 may be used only in the rear waist region 3. It is also possible for the exterior layer 42 to form, in addition to the exterior surface of the chassis 6, the exterior surfaces of the front wings 14 or the rear wings 16. In the diaper 1, the exterior surface 1b of the regions not using the exterior layer 42 may be formed of various types of nonwoven fabrics commonly used in the relevant technical field such as a spun bonded nonwoven fabric or a spunbonded-meltblown-spunbonded nonwoven fabric (SMS nonwoven fabric).

Various embodiments described above by taking the disposable diaper 1 as an example are applicable also to other wearing articles, such as a disposable diaper cover.

Various embodiments described above may be arranged in at least one or more of the following features:
(1) A wearing article having a longitudinal direction, the article including:
a front waist region;
a rear waist region;
a crotch region interposed between the front waist and rear waist regions;
an interior surface configured to face a wearer's skin, and an exterior surface configured to face away from the wearer's skin; and
a mechanical fastener for connecting the front waist region and the rear waist region, wherein:
the mechanical fastener includes a hook element and a loop element adapted to be engaged with the hook element, wherein the hook element is attached to one of the front and rear waist regions and the loop element is formed of a nonwoven fabric of thermoplastic synthetic fibers forming at least part of the exterior surface in at least the other waist region;
the nonwoven fabric has weld regions formed of the thermoplastic synthetic fibers molten and integrally solidified;
the weld regions include
a plurality of first weld lines extending in parallel to each other in a first direction,
a plurality of second weld lines extending in parallel to each other in a second direction intersecting with the first direction, and
a plurality of third weld lines including rows of third weld portions arranged at intervals in a third direction intersecting with the first and second directions; and
the nonwoven fabric further has non-weld regions each having a shape of a parallelogram surrounded by one pair of the adjacent first weld lines and one pair of the adjacent second weld lines, wherein at least a portion of at least one of the third weld portions is present within the non-weld region.

The aspect(s) described in the above item (1) may include at least the following embodiments, which may be taken in isolation or in combination with one another:
(1-1) A dimension of each side of the non-weld region is in a range of 3 to 10 mm, and a distance between each pair of the adjacent first weld lines as well as a distance between each pair of the adjacent second weld lines are at least 2 mm.
(1-2) At least one of the first weld lines is formed of at least one row of first weld portions arranged at predetermined intervals in the first direction.
(1-3) At least one of the first weld lines is formed of a plurality of rows of the first weld portions extending in parallel to each other.
(1-4) Spaces between the adjacent first weld portions in the adjacent rows of the first weld portions are not aligned with each other.
(1-5) At least one of the second weld lines is formed of at least one row of second weld portions arranged at predetermined intervals in the second direction.
(1-6) At least one of the second weld lines is formed of a plurality of rows of the second weld portions extending in parallel to each other.
(1-7) Spaces between the adjacent second weld portions in the adjacent rows of the second weld portions are not aligned with each other.
(1-8) The third direction is parallel to one of diagonals of the non-weld region.
(1-9) The third weld line overlaps with said one of the diagonals and extends in the third direction.
(1-10) The nonwoven fabric is depressed from the exterior surface toward the interior surface in the first, second and third weld lines.
(1-11) The first and second weld lines are obliquely intersected with the longitudinal direction.
(1-12) The wearing article further includes an absorbent structure, which is interposed between the interior surface and the exterior surface in at least the crotch region.
(1-13) The interior surface is defined by a liquid-permeable bodyside liner and the exterior surface is defined by a liquid-impermeable exterior layer.

Various embodiments described in item (1) may be further arranged in at least one or more of the following features:
(2) A wearing article having a longitudinal direction, the article including:
a front waist region;
a rear waist region;
a crotch region interposed between the front waist and rear waist regions;
an interior surface configured to face a wearer's skin, and an exterior surface configured to face away from the wearer's skin; and
a mechanical fastener for connecting the front waist region and the rear waist region, wherein:
the mechanical fastener includes a hook element and a loop element configured to be engaged with the hook element, wherein the hook element is attached to one of the front and rear waist regions and the loop element is formed of a nonwoven fabric of thermoplastic synthetic fibers forming at least part of the exterior surface in the other waist region;
the nonwoven fabric has weld regions formed of the thermoplastic synthetic fibers molten and integrally solidified;
the weld regions include
a plurality of weld lines intersecting each other, and
a plurality of weld portions; and
the nonwoven fabric further has non-weld regions each surrounded by one or more of the weld lines, wherein at least a portion of at least one of the weld portions is present within the non-weld region.

The aspect(s) described in the above item (2) may include at least the following embodiments, which may be taken in isolation or combination with each other.
(2-1) At least one of the weld lines is formed of a single weld portion extending continuously along multiple non-weld regions.
(2-2) At least one of the weld portions intersects at least one of the weld lines and extends across at least two adjacent non-weld regions.
(2-3) The weld portions do not intersect the weld lines.

Various embodiments described in items (1), (2) may include at least the following method.
(3) A method of arranging the first, second and third weld lines in the wearing article includes:
continually feeding a web of thermoplastic synthetic fibers;
welding and depressing the web by passing the web through a pair of embossing/debossing rolls, wherein
at least one of the paired rolls is heated up to a melting temperature of the thermoplastic synthetic fibers, and
the at least one heated roll has, on a peripheral surface thereof, an arrangement of pins or bosses corresponding to an arrangement of the first, second and third weld lines.

The aspect(s) described in the above item (3) may include at least the following embodiment:
(3-1) Upon contact with the pins or bosses of the at least one heated roll, the thermoplastic synthetic fibers in the first, second and third weld lines are welded together so that the welded individual thermoplastic synthetic fibers are not separated from one another to move freely.

The described aspects and/or embodiments provide one or more of the following effects.
The nonwoven fabric defining the exterior surface of the wearing article is adapted to cooperate with the hook element in the mechanical fastener. The nonwoven fabric is formed with the parallelogram non-weld regions each surrounded by the first weld lines and the second weld lines and at least a portion of at least one third weld portion in the third weld line defined by a row of the weld portions arranged at intervals in the third direction intersecting with the first and second directions is present in the non-weld region. Shear force generated between portions the thermoplastic synthetic fibers contained in the non-weld region and the hook element prevents the thermoplastic synthetic fibers from being significantly elongated and facilitates the initial position of fastening to be maintained.
Since the first, second and third weld lines are arranged on the nonwoven fabric defining the exterior surface of the article, the nonwoven fabric is capable of enhancing frictional strength and tensile strength, and preventing excessive fluffiness of the exterior surface.

This application claims the benefit of Japanese Application No. 2012-138238 the entire disclosure of which is incorporated by reference herein.

Claims

A wearing article having a longitudinal direction, the article comprising:
a front waist region;
a rear waist region;
a crotch region interposed between the front waist and rear waist regions;
an interior surface configured to face a wearer's skin, and an exterior surface configured to face away from the wearer's skin; and
a mechanical fastener for connecting the front waist region and the rear waist region, wherein:
the mechanical fastener includes a hook element and a loop element adapted to be engaged with the hook element, wherein the hook element is attached to one of the front and rear waist regions and the loop element is formed of a nonwoven fabric of thermoplastic synthetic fibers forming at least part of the exterior surface in at least another waist region;
the nonwoven fabric has weld regions formed of the thermoplastic synthetic fibers molten and integrally solidified;
the weld regions include
a plurality of first weld lines extending in parallel to each other in a first direction,
a plurality of second weld lines extending in parallel to each other in a second direction intersecting with the first direction, and
a plurality of third weld lines including rows of third weld portions arranged at intervals in a third direction intersecting with the first and second directions; and
the nonwoven fabric further has non-weld regions each having a shape of a parallelogram surrounded by one pair of the adjacent first weld lines and one pair of the adjacent second weld lines, wherein at least a portion of at least one of the third weld portions is present within the non-weld region.
The wearing article according to claim 1, wherein a dimension of each side of the non-weld region is in a range of 3 to 10 mm, and a distance between each pair of the adjacent first weld lines as well as a distance between each pair of the adjacent second weld lines are at least 2 mm.
The wearing article according to claim 1 or 2, wherein at least one of the first weld lines is formed of at least one row of first weld portions arranged at predetermined intervals in the first direction.
The wearing article according to claim 3, wherein at least one of the first weld lines is formed of a plurality of rows of the first weld portions extending in parallel to each other.
The wearing article according to claim 4, wherein spaces between the adjacent first weld portions in the adjacent rows of the first weld portions are not aligned with each other.
The wearing article according to any one of claims 3 to 5, wherein at least one of the second weld lines is formed of at least one row of second weld portions arranged at predetermined intervals in the second direction.
The wearing article according to claim 6, wherein at least one of the second weld lines is formed of a plurality of rows of the second weld portions extending in parallel to each other.
The wearing article according to claim 7, wherein spaces between the adjacent second weld portions in the adjacent rows of the second weld portions are not aligned with each other.
The wearing article according to any one of claims 1 through 8, wherein the third direction is parallel to one of diagonals of the non-weld region.
The wearing article according to claim 9, wherein the third weld line overlaps with said one of the diagonals and extends in the third direction.
The wearing article according to any one of claims 1 through 10, wherein the nonwoven fabric is depressed from the exterior surface toward the interior surface in the first, second and third weld lines.
The wearing article according to any one of claims 1 through 11, wherein the first and second weld lines are obliquely intersected with the longitudinal direction.
The wearing article according to any one of claims 1 through 12, further comprising:
an absorbent structure, which is interposed between the interior surface and the exterior surface in at least the crotch region.
The wearing article according to claim 13, wherein the interior surface is defined by a liquid-permeable bodyside liner and the exterior surface is defined by a liquid-impermeable exterior layer.
A method of arranging the first, second and third weld lines in the wearing article according to claim 1, the method comprising:
continually feeding a web of thermoplastic synthetic fibers;
welding and depressing the web by passing the web through a pair of embossing/debossing rolls, wherein
at least one of the paired rolls is heated up to a melting temperature of the thermoplastic synthetic fibers, and
the at least one heated roll has, on a peripheral surface thereof, an arrangement of pins or bosses corresponding to an arrangement of the first, second and third weld lines.
The method according to claim 15, wherein, upon contact with the pins or bosses of the at least one heated roll, the thermoplastic synthetic fibers in the first, second and third weld lines are welded together so that the welded individual thermoplastic synthetic fibers are not separated from one another to move freely.