The present invention relates to absorbent articles suitable to be used, for example, as sanitary napkins, urine-absorbing pads and panty-liners.
Pad-like absorbent articles adapted to be attached to the interior surface in a crotch region of a pant-type article such as sanitary pants is known. Similar articles extensible in a length direction of the article and adapted to be put on the wearer so as to extend in a front-back direction of the wearer are also known.
For example, an absorbent article disclosed in Patent Literature 1 has a longitudinal direction and a transverse direction being orthogonal to each other and includes a liquid-permeable topsheet, a backsheet, an absorbent body interposed between these two sheets, both end portions opposed to each other in the longitudinal direction and both lateral portions opposed to each other in the transverse direction wherein top- and backsheets have an extensibility in the longitudinal direction, the topsheet has a contractility in the longitudinal direction from a its stretched state property and the absorbent body is formed with slits extending in the transverse direction from the both lateral portions.
{PTL 1}: 2009-153835 A
In conventional sanitary napkins, an extensibility of the topsheet and the backsheet in the longitudinal direction is uniform. When such napkin is subjected to forces opposite in the longitudinal direction, respective portions of the top- and backsheets facing the regions of the absorbent body in which the slits are present are stretched but respective portions of the top- and backsheets facing the regions of the absorbent body in which none of the slits are present are irregularly deformed and, in consequence, the tensile force insufficiently acts on the napkin to stretch the napkin at a desired degree.
An object of the present invention is to provide an absorbent article adapted to be sufficiently stretched when the absorbent article is subjected to tensile forces opposite in the longitudinal direction.
To achieve the object set forth above, the present invention is to improve a pad-shaped absorbent article having a longitudinal direction and a transverse direction, opposite lateral ends and opposite longitudinal sides and includes a liquid-permeable topsheet defining a skin-facing surface, a backsheet defining a garment-facing surface and a disposed an absorbent body between the top- and backsheets.
The present invention is features the absorbent article that the topsheet, the backsheet and the absorbent body respectively have an extensibility in the longitudinal direction; the extensibility of at least one of the topsheet and the backsheet is an elastic extensibility; the sheets have first regions extending across the absorbent body in the transverse direction to express an elastic extensibility and second regions having an elastic extensibility in the longitudinal direction lower than that of the first regions;
the absorbent body has a plurality of slits extending in the transverse direction and expresses an extensibility in the longitudinal direction, when the article is subjected to tensile forces opposite in the longitudinal direction so as to open the slits; and the absorbent body is arranged so that at least one of the slits overlaps with the first regions.
The absorbent article according to one or more of the present invention is arranged so that at least one of the slits of the absorbent body may overlap with the first regions and, consequently, the first regions are elastically stretched as the slits of the absorbent body are opened. Further, one of the sheets has the first regions extending in the transverse direction across the absorbent body to express the elastic extensibility and the second regions having the elastic extensibility in the longitudinal direction lower than that of the first regions. With such arrangement, it is possible to make a deformation in the longitudinal direction significant in the first regions and to make a deformation in the second regions insignificant. In this way, it is possible to subject the article to tensile forces opposite in the longitudinal direction to stretch the article sufficiently in the longitudinal direction.
The drawings illustrate specific embodiments of the present invention includes optional and embodiments as well as essential features of the invention.
The embodiments described below relate to a pad-shaped absorbent article illustrated in
Referring to
The napkin 10 has opposite longitudinal sides 16 and opposite lateral ends 17. The opposite longitudinal sides 16 are respectively formed with wings 20 projecting therefrom in the transverse direction B. The opposite longitudinal sides 16 cooperate with the opposite lateral ends 17 to define a peripheral portion 18 of the napkin 10. The opposite lateral ends 17 have continuous compressed recesses 19a in which the topsheet 11 and the backsheet 12 overlapping with each other are joined together. The opposite longitudinal sides 16 and the associated wings 20 respectively have continually compressed recesses 19b in which the backsheet 12 and side corner sheets 39 being stretchable in the longitudinal direction A and overlapping with the backsheet 12 are joined together. The backsheet 12 and the side corner sheets 39 are joined together also in edges 21 defined between each pair of the compressed recesses 19b adjacent in the longitudinal direction A with adhesive, preferably with elastically stretchable adhesive 22.
Referring again to
In the description of the present invention, as used here, the term “the sheets such as the topsheet 11 are extensible” means that, when a test piece cut out from the sheet so as to have a dimension of 50 mm in the longitudinal direction A and 25 mm in the transverse direction B is set in a tensile tester with respective 10 mm ends in the longitudinal direction A being chucked and the free length of 30 mm in the longitudinal direction A is pulled at a rate of 100 mm/min so that a stretching force (load) of 30 mN in the longitudinal direction A may be applied to the test piece per the dimension of 25 mm in the transverse direction B, a stretch ratio at least in a range of 1.03 to 1.10 (on the assumption that a length dimension in the longitudinal direction A of the sheet is 1.00 when no load is applied thereto, a length in the longitudinal direction A of the sheet is at least in a range of 1.03 to 1.10). As a matter of course, the stretch ratio of the sheet may be higher than 1.10. In the description of the present invention, as used herein, the term “the napkin 10 is extensible” means that, when the opposite lateral ends 17 of the napkin 10 in a range of 10 to 20 mm are gripped by the chucks of the tensile tester and the test piece is subjected to a stretching force of 700 mN/width dimension of 25 mm, the sanitary napkin 10 is stretched between the chucks at a stretch ratio at least in a range of 1.03 to 1.10 without being damaged. The numerical range mentioned above is ensured even when, for example, the topsheet 11 has not elastic extensibility and only the backsheet 12 has an elastic extensibility and, on the assumption that both the topsheet 11 and the backsheet 12 have an elastic extensibility, a stretch ratio of the napkin 10 may be even higher than 1.10. The stretch ratio of the napkin 10 is measured on the napkin 10 having the side corner sheets 39 removed therefrom. The sanitary napkin 10 is stretched preferably at a rate of 100 mm/min. As used herein, the term “the sheet has an elastic extensibility” means a behavior such that, when the sheet is subjected to a stretching force until the sheet is stretched in the longitudinal direction A to a length 2.00 times of the initial length and immediately thereafter the sheet is released from the stretching force, the sheet regains its length 1.50 times or less of the initial length thereof. If it is impossible for the sheet to regain its length 1.50 times or less of the initial length thereof, it is meant that such sheet has an inelastic extensibility. As used herein, the term “such napkin 10 is subjected to tensile forces opposite to each other in the longitudinal direction A” means that the opposite lateral ends 17 of the napkin 10 are respectively grasped and pulled so as to be distanced from each other in the longitudinal direction A or the one ends 17 is fixed and the other end 17 is pulled so as to be distanced from the one end 17.
Referring to
The first sheet 23, when this is liquid-impermeable, may be formed of plastic films, for example, plastic films such as polyethylene resin films. The first sheet 23, when this is breathable and liquid-impermeable, may be formed of plastic films such as oriented polyethylene resin films containing fine particles of inorganic material, for example, calcium carbonate or barium sulfate as fillers. The first sheet 23 is formed with a plurality of pleats 25 extending across the absorbent body 13 from one of the longitudinal side 16 to the other longitudinal side 16. A plurality of pleats 25 are adjacent one to another in the longitudinal direction A to define each multi-pleats region 26. Between each pair of the multi-pleats regions, a pleat-free region 27 is defined. In such backsheet 12, the nonstretchable first sheet 23 defining the multi-pleats regions 26 cooperates with the elastically extensible second sheets 24 to define first regions 29 expressing an elastic extensibility and, in the respective pleat-free regions 27, second regions 30 in which the elastic extensibility in the longitudinal direction A is lower than that in the first regions 29. A cross-sectional shape of the pleats 25 taken in the longitudinal direction A is corrugated as exemplarily illustrated in
The second sheets 24 are formed of a plastic film having a rubber elasticity, for example, polyurethane resin films and laid between the first sheet 23 and the absorbent body 13 so as to overlap the multi-pleats regions 26, preferably so as to cover the entirety of the multi-pleats regions 26. These second sheets 24 are joined, in their elastically relaxed condition, to the pleat-free regions 27 of the first sheet 23 through, for example, hot melt adhesive 37 (see
The respective second sheets 24 are distanced one from another in the longitudinal direction A to avoid a possibility that the pleat-free region 27 defined between each pair of the adjacent multi-pleats regions 26 might be entirely covered with the respective second sheets 24. With such arrangement, the respective pleat-free regions 27 directly face the absorbent body 13 not through the intermediary of the second sheets 24.
The pleat-free regions 27 are respectively provided on the garment-facing surfaces 12a with attachment regions 35 formed of, for example, pressure-sensitive adhesives so that the pleat-free regions 27 may be attached to the garment in a peelable manner. These attachment regions 35 are protectively covered with respective separators 36 indicated by imaginary lines during a period elapsing from production of the napkin to actual use thereof. A plurality of the attachment regions 35 formed on the napkin are sufficiently distanced from each other in the longitudinal direction A to prevent the extensibility of the napkin in the longitudinal direction A from being inhibited.
The pleat-free regions 27 in the respective wings 20 also are provided with the attachment regions 35. In this manner, all the attachment regions 35 are arranged unexceptionally in the pleat-free regions 27 of the napkin 10. In this regard, when the napkin 10 is put on the wearer' body, the wings 20 are folded back so as to overlap the exterior surface of the garment's crotch region and attached to the garments through the intermediary of the respective attachment regions 35. If the wings 20 are provided with the multi-pleats regions 26, there is a likelihood that these multi-pleats regions 26 might make it difficult to fold the wings onto the exterior surface of the garments when the napkin 10 is attached to the clothes . To avoid such likelihood, the wings are preferably formed with none of the multi-pleats regions, though not illustrated.
Referring to
The absorbent body 13 has a plurality of central region slits 33a and lateral region slits 33b. The respective central region slits 33a are arranged in the central region of the absorbent body as viewed in the transverse direction B so as to extend across the center line P, thereby dividing the absorbent body 13 partially in the longitudinal direction A. In other words, the absorbent body 13 is continuous in the longitudinal direction A on both lateral side regions in the transverse direction B of the central region slits 33a since none of the central region slits 33a extends to the opposite longitudinal sides 31. The lateral region slits 33b are arranged so as to extend from the opposite longitudinal sides 31 toward the central line P in the transverse direction B. In other words, the absorbent body 13 is continuous in the longitudinal direction A on the sides of the lateral region slits 33b close to the central line P since none of the lateral region slits 33b extends to the central line P. Preferably, these central region slits 33a and lateral region slits 33b are formed symmetrically about the center line P and extend through the absorbent body 13 in a thickness direction. While each of the slits 33a, 33b is preferably shaped in a curved line such as a waved line, a linear each of the slits 33a, 33b maybe a liner slit. However, in comparison with the linear slits, the slits 33a, 33b shaped in the wave-like curved lines more effectively alleviate an uncomfortable feeling which the wearer might experience when the absorbent body 13 is inelastically stretched in the longitudinal direction A. For the absorbent body 13 having such slits 33a, 33b, the inelastic extensibility in the longitudinal direction A is relatively high in the regions in which the slits 33a, 33b are present and the inelastic extensibility in the longitudinal direction A is relatively low in the region in which the slits 33a, 33b are not present. While, in this napkin 10, the absorbent body 13 and the backsheet 12 are arranged and joined together so that all the central region slits 33a may overlap with the first regions 29, it is also possible to arrange the absorbent body 13 and the backsheet 12 and to join them together so that at least one of the slits 33a and 33b overlap with the first regions 29.
The absorbent body 13 is joined to the topsheet 11 and/or the backsheet layer 12, for example, with hot melt adhesive (not shown) and the central region slits 33a and the lateral region slits 33b are in closed state so far as the absorbent body 13 is not subjected to a tensile force in the longitudinal direction A. For the absorbent body 13 joined to the backsheet layer 12, the absorbent body 13 is preferably joined to the backsheet layer 12 in the pleat-free regions 27 of the first sheet 23 so that the second sheets 24 may be extended in the longitudinal direction A without any interference. However, it is possible within the scope of the present invention to join the absorbent body 13 to the first sheet 23 in the multi-pleats regions 26 or to join the absorbent body 13 to part of the second sheets 24.
Referring to
In addition, according to this embodiment of the napkin 10, the absorbent body 13 and second sheets are joined together in a manner that all the central region slits 33a of the absorbent body 13 overlap with the first regions 29. With such arrangement, the first regions 29 are elastically expanded as the central region slits 33a of the absorbent body 13 are opened. Furthermore, the backsheet 12 has the first regions 29 extending in the transverse direction B across the absorbent body 13 and expressing the elastic extensibility and the second region 30 in which the elastic extensibility in the longitudinal direction A is lower than that in the first regions 29. With such arrangement, it is possible to make a deformation in the first regions 29 significant and to make a deformation in the second regions 30 insignificant. Whereby, it is possible to subject the napkin 10 to tensile forces opposite to each other in the longitudinal direction A so that the napkin 10 may be sufficiently expanded in the longitudinal direction A. Furthermore, in the napkin 10 according to the present embodiment, the slit-free regions of the absorbent body 13 and the second regions 30 are arranged so as to overlap with each other and joined together so that the deformation of the napkin 10 in the second regions 30 may be further restricted to ensure the above-mentioned effect (sufficient extension of the napkin 10 in the longitudinal direction A ensured by subjecting the napkin to the tensile forces opposite to each other in the longitudinal direction A)
The central region slits 33a arranged in the absorbent body 13 facilitate the napkin 10 to be stretched in the longitudinal direction A merely by pinching regions on the central line P of the opposite lateral ends 17 and pulling the napkin 10 in the longitudinal direction A without being affected by the backsheet 12 and the side corner sheets 39 joined together in the respective longitudinal sides 16. In view of this, the users may recognize this advantageous property merely by pinching the lateral ends 17 and pulling the napkin in the longitudinal direction A and select the napkin 10 according to the present invention without hesitation from various types of napkin commercially available.
Referring again to
The napkin 10 in which the absorbent body 13 and the backsheet 12 are arranged and joined to each other in the manner that all the central region slits 33a overlap with the first regions 29 has been described above as the napkin 10 according to the first embodiment of the present invention. However, it is possible within the scope of the present invention, though not illustrated, to arrange the absorbent body and the backsheet and to join them to each other in a manner that all the central region slits overlap with the first regions 29 and all the lateral region slits also overlap with the first regions. Here, the absorbent body and the backsheet are arranged and joined to each other in a manner that a region not formed with the central region slits, a region not formed with the lateral region slits and the second regions overlap together.
Referring to
Referring to
In this napkin 10, the side corner sheets 39, the topsheet layer 41 and the absorbent body 13 are arranged and joined together in a manner that all the slits 43b of the side corner sheets 39, all the slits 43a of the topsheet layer 41 and all the slits 33a, 33b of the absorbent body 13 overlap with each other. In this napkin 10, the slits 43b of the side corner sheets 39 and the slits 43a of the topsheet 41 facilitate the slits 33a, 33b of the absorbent body 13 to be opened. In this regard, while all the slits 43a, 43b of the topsheet 41 and the side corner sheets 39 preferably overlap with the slits 33a, 33b of the absorbent body 13, at least respective ones of the slits 43a, 43b of the topsheet 41 and the side corner sheets 39 may overlap with the associated slits 33a, 33b of the absorbent body 13 to ensure the desired effect.
Referring to
The first regions 44 and the second regions 45 respectively extend across the absorbent body 13. According to this embodiment, assuming that, for example, a backsheet 52 has not the elastic extensibility and the topsheet 51 has the elastic extendibility, when the napkin 10 is subjected to a stretching force of 700 mN in the longitudinal direction A per a dimension of 25.0 mm in the transverse direction B, a stretch ratio of the napkin 10 is at least in a range of 1.03 to 1.10. Of course, the stress ratio of the napkin 10 may excess 1.10.
The topsheet 51 and the absorbent body 13 are arranged and joint to each other in a manner that the first regions 44 of the topsheet 51 and all the central region slits 33a of the absorbent body 13 overlap with each other. In this regard, the topsheet 51 and the absorbent body 13 may be arranged and joined to each other in a manner that the first regions 44 of the topsheet 51 overlap with at least respective ones of the slits 33a, 33b of the absorbent body 13.
Referring to
For this napkin 10, the absorbent body 13 and the topsheet are arranged and joined to each other in a manner that all the central region slits 33a of the absorbent body 13 overlap with the first regions 44 so that the first regions 44 may be elastically stretched along with opening of the central region slits 33a of the absorbent body 13. Further, the topsheet 51 has the first regions 44 extending in the transverse direction B across the absorbent body 13 to express an elastic extensibility and the second regions 45 having an elastic extensibility in the longitudinal direction A lower than that of the first regions 44. With such arrangement, it is possible to make a deformation in the first regions 44 significant and to make a deformation in the second regions 45 insignificant in the longitudinal direction A. In this way, the napkin 10 may be subjected to tensile forces opposite to each other in the longitudinal direction A to stretch the napkin 10 sufficiently in the longitudinal direction A. Furthermore, for this napkin 10, the topsheet 51 and the absorbent body 13 are arranged and joined to each other in a manner that the slit-free regions of the absorbent body 13 and the second regions 45 overlap with each other. Such arrangement makes the deformation of the napkin in the second regions 45 further insignificant so that the above-mentioned effect (the napkin 10 is subjected to a pair of tensile forces opposite in the longitudinal direction A and whereby the napkin 10 is sufficiently stretched in the longitudinal direction A) may be ensured.
While the first sheet 23 formed in its approximately entire area except the opposite lateral ends 17, the wings 20 and the midportion in the longitudinal direction A with the pleats 25 has been exemplarily described above, the first sheet 23 may be formed in its approximately entire area in the longitudinal direction A except the opposite lateral ends 17 with the pleats 25 as far as the operation and the effects to be provided by the present invention are assured.
Referring to
In this napkin 10, the top- and backsheets 51, 12 and the absorbent body 13 are arranged and joined together in a manner that all the central region slits 33a, the first regions 44 of the topsheet 51 and the first regions 29 of the backsheet 12 overlap with each other.
According to this embodiment also, when the napkin 10 having the central region slits 33a opened under a pair of tensile forces opposite in the longitudinal direction A is released from such tensile forces, the central region slits 33a rapidly restore the initial state under the contractile force (contractile force of the topsheet 51 and the contractile force of the second sheets 24 of the backsheet 12) of the sheets 12, 51 arranged on the skin-facing surface 11a and the garment-facing surface 12a, respectively.
The disclosure relating to the present invention described above may be arranged at least as follows:
The present invention relates to a pad-shaped absorbent article having a longitudinal direction and a transverse direction being orthogonal to each other, opposite lateral ends and opposite longitudinal sides and including a liquid-permeable topsheet defining a skin-facing surface, a backsheet defining a garment-facing surface and an body exudate absorbent body interposed between the top- and backsheets, wherein: the topsheet, the backsheet layer and the absorbent body respectively have an extensibility in the longitudinal direction; the extensibility of at least one of the topsheet layer and the backsheet is an elastic extensibility; the sheets have first regions extending across the absorbent body in the transverse direction to express an elastic extensibility and second regions having an elastic extensibility in the longitudinal direction lower than that of the first regions; and the absorbent body has a plurality of slits extending in the transverse direction and expresses an extensibility in the longitudinal direction, when the article is subjected to a pair of tensile forces opposite in the longitudinal direction so as to open the slits; and the absorbent body is arranged so that at least one of the slits overlaps with the first regions.
The present invention disclosed in the paragraph [0054] may include embodiments at least as described below:
(1) The sheet is the backsheet; the first regions in the backsheet are formed with the first regions defined by a non-extensible first sheet formed with multi-pleats regions each defined by a plurality of pleats extending in the transverse direction and lying side-by-side in the longitudinal direction and elastically extensible second sheets lying between the first sheet and the absorbent body and joined to the first sheet so as to extend across the absorbent body in the transverse direction and to extend across the multi-pleats regions in the longitudinal direction; the backsheet is formed with the multi-pleats regions arranged at intervals in the longitudinal direction and the second regions, i.e., non-extensible pleat-free region defined between each pair of the adjacent multi-pleats regions; and the absorbent body and the backsheet are jointed to each other.
(2) The topsheet is formed of a non-extensible material; the topsheet has a plurality of slits extending in the transverse direction and when the article is subjected to tensile forces opposite in the longitudinal direction, the slits are opened and thereupon an extensibility in the longitudinal direction is expressed; and at least one of the slits of the topsheet overlaps with the slits of the absorbent body.
(3) The second sheets are joined to the pleat-free regions.
(4) The second regions of the backsheet are provided with attachment regions to garment.
(5) The sheet is the topsheet formed of an elastic fibrous nonwoven fabric and having the first region and the second regions; and the absorbent body and the topsheet layer are joined to each other.
(6) The topsheet and the backsheet respectively have the first region and the second regions; and at least one of the slits of the absorbent body overlaps with the first region of the topsheet and the first region of the backsheet.
(7) A stretch ratio of the article is at least in a range of 1.03 to 1.10 when the article is subjected to a tensile force of 700 mN in the longitudinal direction per a dimension of 25.0 mm in the transverse direction.
(8) The absorbent body has both side edges extending in the longitudinal direction and central region slits in a central area as viewed in the transverse direction arranged in a manner that the none of the central region slits extends to at least one of the both side edges in a total range in the longitudinal direction; and the absorbent body has at least two central region pleats.
(9) The article has a center line extending in the longitudinal direction so as to bisect a dimension of the article; the absorbent body has lateral edges opposed to each other in the transverse direction and extending in the longitudinal direction and lateral region slits extending in the transverse direction from the lateral edges toward the center line but not to the center line in a total range in the longitudinal direction; and the absorbent body has at least two lateral region slits.
The terms “first” and “second” used in the specification and claims of the present invention are used merely to distinguish the similar elements, similar positions or the other similar items.
Number | Date | Country | Kind |
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2014-135425 | Jun 2014 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2015/061940 | 4/20/2015 | WO | 00 |