Disposable hygiene article with improved fit
11395771 · 2022-07-26
Assignee
Inventors
Cpc classification
A61F13/47272
HUMAN NECESSITIES
A61F13/4704
HUMAN NECESSITIES
A61F13/4756
HUMAN NECESSITIES
A61F13/5616
HUMAN NECESSITIES
International classification
A61F13/15
HUMAN NECESSITIES
Abstract
The present invention relates to a disposable hygiene article comprising a pair of curved compression lines in a rear portion of the article. The article has a core with a first region which has its narrowest width (M) in the transverse direction (x) in a front portion or at a location of a transition between the front portion and a crotch portion of the article. The absorbent core in the rear portion comprises the first (L1, R1) and second (L2, R2) pairs of rear compression lines, which extend in a longitudinal direction (y) between respective front and rear endpoints. A transverse distance (G3min) separates the rear endpoints of the pair of compression lines whilst a second, larger distance (G3max) separates the front endpoints of the compression lines.
Claims
1. A disposable hygiene article comprising a transverse direction (x), a longitudinal direction (y) and a longitudinal centre line (A) dividing the article into left-hand and right-hand portions (I) and (II), whereby said article has a front portion, a crotch portion and a rear portion, and said article comprises a liquid-permeable topsheet, a liquid-impermeable backsheet, an absorbent core arranged between the topsheet and backsheet, wherein an outer contour of the absorbent core is defined by mutually symmetrical mirror-imaged portions arranged symmetrically about the centerline (A), and defined by first and second core edge lines, and the core is delimited by a core front edge in the front portion and a core rear edge in the rear portion, whereby said absorbent core comprises a first region extending in the longitudinal direction (y) of the article from a first region front edge in the front portion over the crotch portion to the rear portion, and wherein the outer contour of the first region is defined by mirror-imaged first and second first region edge lines, and whereby said first region comprises a head part and two leg portions extending symmetrically about the centre line (A) and in a longitudinal direction (y) of the article, starting and diverging from a common leg portion start point (a.sub.0) in the crotch portion and extending over a portion of the crotch portion towards separate leg portion endings in the rear portion, whereby a distance (a.sub.x) between facing sides of the respective leg portions in the transverse direction (x) varies in the longitudinal direction (y), whereby a maximum distance (a.sub.1) between the facing sides of the respective leg portions in the transverse direction (x) is in the crotch portion, located at a position in the longitudinal direction (y) corresponding to a position of a crotch point, whereby said facing sides of the respective leg portions converge backwards in the longitudinal direction (y) such that said distance (a.sub.x) is reduced from said maximum distance (a.sub.1) to a minimum distance (a.sub.2), whereby said absorbent core further comprises a second region at least partially surrounded by said first region and extending between said leg portions in the transverse direction (x) and in the length direction (y) from the leg portion start point (a.sub.0) in the crotch portion to an endpoint (a.sub.1) in the rear portion, and wherein: the second region has an average density which is at least 20% lower than the average density of the first region, the absorbent core comprises a first left rear compression line (L1) and a first right rear compression line (R1), wherein the first left and right rear compression lines mutually diverge and curve away from the longitudinal centre line in a forward direction, the first and second compression lines (L1, R1) being mutually symmetric about the longitudinal centerline, wherein the first left rear compression line (L1) comprises a curve extending from a front endpoint (PF.sub.L1) located at or adjacent to a transversally outer left edge of the first leg portion to a rear endpoint (PR.sub.R1) located at or adjacent to an inner right edge of the first leg portion, wherein the first right rear compression line (R1) comprises a curve extending from a front endpoint (PF.sub.R1) located at or adjacent to a transversally outer right edge of the second leg portion to a rear endpoint (PR.sub.R1) located at or adjacent to an inner left edge of the second leg portion, wherein a distance G3 is defined in the transverse direction (x) between opposing mirror image-points on the first pair of rear compression lines (L1, R1), and wherein the distance G3 increases in a forward direction from a minimum distance G3.sub.min between the rear endpoints of the first pair compression lines (L1, R1) to a maximum distance G3.sub.max between the front endpoints of the first pair of compression lines (L1, R1), and wherein the distance (G3min) is a minimum distance between the left and right compression lines (L1, R1).
2. The disposable hygiene article according to claim 1, wherein the first region has its narrowest width in the transverse direction (x) in the front portion or at the location of a transition between the front portion and the crotch portion.
3. The disposable hygiene article according to claim 1, wherein a boundary is defined between the first region and the second region of the core between the first and second leg portions, to form: a first boundary line between an inner edge of the first leg and the second region; and a second boundary line between an inner edge of the second leg and the second region, wherein the first boundary line forms a tangential extension of the left curved compression line (L1) at its rear endpoint (PR.sub.L1) and wherein the second boundary line forms a tangential extension of the right curved compression line (R1) at its rear endpoint (PR.sub.R1).
4. The disposable hygiene article according to claim 1, wherein each of the first left and right compression lines (L1, R1) comprises a smooth curve.
5. The disposable hygiene article according to claim 1, wherein the first left and right compression lines (L1, R1) are continuously and increasingly divergent as they extend in the forward direction.
6. The disposable hygiene article according to claim 1, wherein the distance G3min is between 5-20 mm.
7. The disposable hygiene article according to claim 1, wherein the first left and right rear compression lines (L1, R1) are obtained by means of groove compressing the core and optionally the acquisition sheet and/or the topsheet with high pressure compression from the topsheet side of the article.
8. The disposable hygiene article according to claim 1, further comprising first and second front compression lines, said first and second front compression lines being symmetrically arranged either side of the centre line (A).
9. The disposable hygiene article according to claim 8, wherein the first front compression line extends from a front endpoint (PF.sub.1) to a rear endpoint (PR.sub.1) via a first turning point, and wherein: the front endpoint (PF.sub.1) of the first front compression lines is located at or adjacent to an outer edge region of the first region of the absorbent core left of the longitudinal centre line (A) and forward of the narrowest width (M), the rear endpoint (PR.sub.1) of the first front compression line is located at or adjacent to an outer edge region of the first region of the absorbent core left of the centre line (A) and behind the narrowest width (M), and the first turning point (T1) is located left of the centre line A) and right of the front and rear endpoints of the first front compression line in the transverse direction (x), and between the front and rear endpoints of the first front compression lines in the longitudinal direction (y), wherein the second front compression line extends from a front endpoint (PF.sub.2) to a rear endpoint (PR.sub.2) via a second turning point, and wherein: the front endpoint (PF.sub.2) of the second front compression lines is located at or adjacent to an outer edge region of the first region of the absorbent core right of the longitudinal centre line (A) and forward of the narrowest width (M), the rear endpoint (PR.sub.2) is located at or adjacent to an outer edge region of the first region of the absorbent core right of the centre line (A) and behind the narrowest portion (M), and the second turning point (T2) is located right of the centre line (A) and left of the front and rear endpoints of the second front compression line in the transverse direction (x), and between the front and rear endpoints of the second front compression line in the longitudinal direction (y).
10. The disposable hygiene article according to claim 9, wherein the first front compression line and the second front compression line are spaced from each other by a minimum distance D1 between their respective turning points (T1, T2), and wherein the distance D1 is at least 1 mm in a transverse direction.
11. The disposable hygiene article according to claim 1, wherein the second region comprises a centre region extending symmetrically about the centre line (A) and having a longer extension in the longitudinal direction (y) than in the transverse direction (x), and a longitudinally and symmetrically about the centre line (A) extending rear section in contact with the centre region, and the centre region and the rear section being limited by the facing sides of the respective leg portions.
12. The disposable hygiene article according to claim 11, wherein the centre region comprises a weakening compression line extending along the centre line (A) between a start point (a.sub.0) and a centre region endpoint (a.sub.e).
13. The disposable hygiene article according to claim 11, wherein a maximum width (a.sub.1) of the centre region is 10-50 mm and a length is from 50-110 mm, and the minimum width (a.sub.2) of a rear section limited by the facing sides of the respective leg portions is 5-30 mm and a length is from 30-110 mm.
14. The disposable hygiene article according to claim 11, wherein the centre region extends in a thickness direction of the article such that it protrudes outwards from a plane of the first region.
15. The disposable hygiene article according to claim 1, wherein the first region of the core has an average density of an absorbent material from 150-220 kg/m.sup.3, and the second region has an average density of an absorbent material from 70-150 kg/m.sup.3.
16. The disposable hygiene article according to claim 1, further comprising a second pair of rear compression lines (L2, R2), wherein the second pair of rear compression lines comprises a second left compression line (L2) and a second right compression lines (R2), and wherein: the second left rear compression line (L2) extends from a front endpoint (PF.sub.L2) located at or adjacent to a transversally outer left edge of the first leg portion to a rear endpoint (PR.sub.L2) located at or adjacent to an inner right edge of the first leg portion, and the second right rear compression line (R2) extends from a front endpoint (PF.sub.R2) located at or adjacent to a transversally right edge of the second leg portion to a rear endpoint (PR.sub.R2) located at or adjacent to an inner left edge of the second leg portion.
17. The disposable hygiene article according to claim 16, wherein a distance G4 is defined in the transverse direction (x) between opposing mirror-image points on the second pair of rear compression lines (L2, R2), and wherein the G4 increases from a minimum distance G4.sub.min between the rear endpoints of the second pair of compression lines (L2, R2) to a maximum distance G4.sub.max between front endpoints of the second pair of compression lines (L2, R2).
18. The disposable hygiene article according to claim 16, wherein each of the compression lines of the second pair of rear compression lines (L2, R2) is curved.
19. The disposable hygiene article according to claim 16, wherein each of the compression lines of the second pair of rear compression lines (L2, R2) is straight.
20. The disposable hygiene article according to claim 18, wherein the first and second left rear compression lines (L1, L2) are parallel, and wherein the first and second right rear compression lines (R1, R2) are parallel.
21. The disposable hygiene article according to claim 9, wherein the point of minimum width D1 between the front compression lines and the point of minimum width (G3min) between the first pair of rear compression lines (L1, R1) are spaced apart from each other in a longitudinal direction by a distance G8, wherein the distance G8 is between 80-200 mm.
22. The disposable hygiene article according to claim 9, wherein the point of minimum distance D1 between the first and second front compression lines is spaced from the narrowest width (M) of the core by 0-15 mm and preferably with the minimum distance D1 located forward of the narrowest width (M).
23. The disposable hygiene article according to claim 1, wherein a longitudinal distance G1 between the respective front and rear endpoints of the first left and right rear compression lines (L1, R1) is between 15-80 mm.
24. The disposable hygiene article according to claim 1, wherein the higher average density of the absorbent material is obtained by means of compression and/or providing an embossing pattern to the first region which covers at least portion of the first region, and wherein the second region is free of the embossing pattern.
25. The disposable hygiene article according to claim 24, wherein said first region is compressed more than the second region, and the first region is stiffer than the second region.
26. The disposable hygiene article of claim 24, wherein the embossing pattern comprises individual dots placed in a predetermined pattern.
27. The disposable hygiene article according to claim 1, wherein the narrowest width (M) of the first region of the core in said front portion is from 15 to 60 mm in the transverse direction (x).
28. The disposable hygiene article according to claim 1, wherein the second region covers from 10-50% of a total area of the core.
29. A method for the manufacture of the disposable article according to claim 1, comprising the steps of: feeding a liquid-permeable topsheet material layer, a liquid-impermeable backsheet material layer and an absorbent material layer arranged to be positioned in between the topsheet material layer and the backsheet material layer, forming the first region and second region of the core by compressing the first region more than the second region and/or by embossing an embossing pattern to areas providing the first region in the core, and forming the first left rear compression line (L1) and the first right rear compression line, by means of high pressure compression from the topsheet side of the core.
30. The method according to claim 29, further comprising the step of providing a weakening compression line extending along the centre line (A) between a start point (a.sub.0) and a centre region endpoint (a.sub.e).
31. The method according to claim 29, wherein the method further comprises providing a liquid acquisition sheet between the topsheet material layer and the absorbent material layer.
32. The method according to claim 29, wherein the first region is formed prior to marriage of the backsheet to the absorbent core, topsheet and optional liquid acquisition sheet of the article.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The present invention will now be described with reference to a number of non-limiting illustrative embodiments, in which:
(2)
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DETAILED DESCRIPTION OF THE INVENTION
(11) The present disposable hygiene article is an absorbent article aimed for personal hygiene and may be, for example, a sanitary towel, a panty liner, an incontinence pad, or a diaper. Such articles are commonly used for acquisition and storage of bodily exudates such as urine, faeces or menstrual fluid. The absorbent article is disposable, which means that it is intended to be used only once and disposed thereafter, rather than being cleaned and re-used. The absorbent article may suitably be a sanitary towel, and the design of the article is particularly suitable for sanitary towels.
(12)
(13) The article 1 comprises a front portion 2, a crotch portion 3, and a rear portion 4. The article 1 comprises a liquid-permeable topsheet 30, a liquid-impermeable backsheet 31, and an absorbent core 6 arranged between the topsheet 30 and the backsheet 31. An outer contour of the absorbent core 6 is defined by mirror-imaged first and second core edge lines 8, 9, and the absorbent core 6 is delimited by a core front edge 7 in the front portion 2 and a core rear edge 57 in the rear portion 4.
(14) The absorbent core 6 comprises a first region 12 extending in the longitudinal direction y of the article 1 from the front portion 2 over the crotch portion 3 to the rear portion 4 wherein an outer contour of the first region 12 is defined by mirror-imaged first and second first region edge lines 22, 23 and a first region front edge 67 and a first region rear edge 37.
(15) The core 6 also comprises a second region 24 (which will be described in more detail with reference to
(16) In the embodiment shown in
(17) As shown in
(18) As shown in
(19) As shown in
(20) The first left compression line L1 is formed in the first longitudinal portion I of the article 1, with its front endpoint PF.sub.L1 positioned on, by, or adjacent to the outer left edge 8 of the first region 12 of the core 6. The rear endpoint PR.sub.L1 of the first left rear compression line L1 lies on, by, or adjacent to an inner edge 19′ of the first leg portion 15. The first right rear compression line R1 is arranged in a corresponding and mirror-imaged manner on the second longitudinal portion II of the article 1.
(21) By a “front endpoint” it is meant the forward most point of the respective compression line, i.e., an end of the compression line closest to the front region of the article. By a “rear endpoint” it is meant the rearmost point of the respective compression line, i.e., an end of the compression line closest to the rear edge of the article.
(22)
(23) As shown in
(24) The first pair of rear compression lines L1, R1 curve away from each other. At their closest point, the first left and right compression lines L1, R1 are separated from each other by a minimum distance G3min, measured in a transverse direction x. The minimum distance G3min between the first left and right rear compression lines L1. R1 is between the rear endpoints PR.sub.L1, R1. The maximum distance G3max between the first left and right rear compression lines (L1, R1) is, in the transverse direction x, between the front endpoints PF.sub.L1, R1 of the first left and right rear compression lines. The first left and right compression lines are arranged so that the distance between symmetrically opposite points on the respective compression lines increases continuously as the compression lines L1, R1 extend in the forward direction. Moreover, the first left and right rear compression lines L1, R1 are arranged such that they are convex with respect to the centre line A. Thus, the left and right rear compression lines L1, R1 become increasingly divergent as they extend in the forward direction.
(25) In one embodiment, the first pair of rear compression lines L1, R1 is configured to allow the hygiene article to conform to a curvature of a user's body in the region of the perineum in between the buttocks. The curvature of the compression lines allows the article to flex to conform to the region of the perineum, whilst the rear part of the compression lines (which approach each other almost parallel and in the longitudinal direction) allow the article to crease generally along the longitudinal centre line A to form a ridge in the rear portion of the article, which can closely adapt to the cleft between the user's buttocks. The improved fit offered by such a configuration may provide increased comfort for the user and improved security against leakage, when compared to conventional sanitary napkins.
(26) As shown in
(27) Due to the curvature and positioning of the first pair of rear compression lines L1, R1 relative to the leg portions 15, 16 of the core, the compression lines can control the bending of the article in a favorable manner.
(28) The advantages of the present invention can be achieved with minimal disruption to or modification of known manufacturing techniques. In a production method suitable for manufacturing articles according to the present invention, a liquid-permeable topsheet material layer 30, a liquid-impermeable backsheet material layer, and an absorbent material layer are fed into the manufacturing equipment. The core is arranged to be positioned in between the topsheet material layer 30 and the backsheet material layer. An optional acquisition material layer is arranged to be positioned between the topsheet material layer 30 and the absorbent material layer. Before, during, or after the marriage of the above-described materials to form an absorbent article, the compression lines 101, 102 are compressed by means of high pressure compression from the topsheet or the backsheet side of the core. In preferred embodiments, the compression lines are formed prior to marriage of the backsheet to the absorbent core, topsheet, and the optional liquid acquisition sheet 36 of the article.
(29) Turning now to
(30) As shown in
(31) The total length of the article 1 in the longitudinal direction is length b, which is the sum of a length b1 of a front portion 2, a length b2 of a crotch portion 3 and a length b3 of a rear portion 4, and sums up to 100% length of the article. The front portion 2, a crotch portion 3 and a rear portion 4 are arranged in the article's longitudinal direction as well as a transition 5 between the front portion 2 and the crotch portion 3. A first Imaginary line 230 extends in a transverse direction to separate the front portion 2 from the crotch portion 3, and a second imaginary line extends in the transverse direction to separate the crotch portion 3 from the rear portion 4. The article comprises an absorbent core 6.
(32) The disposable hygiene articles depicted in
(33) The skilled person will appreciate that although the present invention is suitable for use in a wide range of article comprising different rear extensions, the advantages of the present invention may be particularly beneficial in article with a longer rear extension.
(34) In use, the front portion 2 of the article 1 is intended to cover at least partly the pubic region of a female wearer. The front portion 2 is delimited by the front transverse edge 27 of the article 1. Furthermore, the front portion 2 extends a certain length b1 along the article 1 in the longitudinal direction. In a sanitary napkin of the type shown, the front portion 2 has a length b1 in the longitudinal direction which is between 10-50%, more preferably between 10-40%, most preferably between 15-25% of the total length b of the article 1. The length can be, for example, between 30-70 mm, such as between 40-60 mm.
(35) The crotch portion 3 of the article 1 is located adjacent to the front portion 2 in the longitudinal direction. In use, the crotch portion 3 lies between the legs of the user and covers a female user's genital region. In a sanitary napkin of the type shown, the crotch portion 3 has a length b2 in the longitudinal direction which is between 25-60%, more preferably between 30-55%, most preferably between 30-50% of the total length b of the article. Typically, the length b2 of the crotch portion 3 in the longitudinal direction y is between 60-150 mm, such as between 80-120 mm.
(36) The rear portion 4 is located at the opposite end of the article 1 from the front portion 2 and is located adjacent to the crotch portion 3 in the longitudinal direction. In use, the rear portion 4 extends towards the user's rear. The rear portion 4 is defined by the rear transverse edge 47 of the article 1 and extends a certain length b3 along the article 1 in the longitudinal direction, and is longitudinally distanced from a centre region 25 of an absorbent core 6. In a sanitary napkin of the type shown, the rear portion 4 has a length b3 in the longitudinal direction which is between 15-40%, more preferably between 20-35%, most preferably between 20-30% of the total length b of the article 1. The length b3 can be, for example, from 60 to 100 mm, such as between 70-90 mm. The length b3 in the rear portion 4 of the article can be extended.
(37) The disposable hygiene article of the present disclosure comprises an absorbent core, which is indicated in the figures with reference sign 6. The “absorbent core” is the absorbent structure of the article which acquires and stores bodily fluids. The absorbent core may be of any conventional kind. Examples of commonly occurring absorbent materials are cellulosic fluff pulp, tissue, highly absorbent polymers (so called superabsorbents), absorbent foam materials, absorbent nonwoven materials or the like. It is common to combine cellulosic fluff pulp with superabsorbent polymers in an absorbent core. Superabsorbent polymers are water-swellable, water-insoluble organic or inorganic materials capable of absorbing at least about 20 times their own weight of an aqueous solution containing 0.9 weight percent of sodium chloride. Organic materials suitable for use as a superabsorbent material can include natural materials such as polysaccharides, polypeptides and the like, as well as synthetic materials such as synthetic hydrogel polymers. Such hydrogel polymers include, for example, alkali metal salts of polyacrylic acids, polyacrylamides, polyvinyl alcohol, polyacrylates, polyacrylamides, polyvinyl pyridines, and the like. Other suitable polymers include hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, and isobutylene maleic anhydride copolymers and mixtures thereof. The hydrogel polymers are preferably lightly cross-linked to render the material substantially water insoluble. Preferred superabsorbent materials are further surface cross-linked so that the outer surface or shell of the superabsorbent particle, fibre, flake, sphere, etc., possesses a higher crosslink density than the inner portion of the superabsorbent. The superabsorbent materials may be in any form suitable for use in absorbent composites including particles, fibres, flakes, spheres, and the like. A high absorption capacity is provided by the use of high amounts of superabsorbent material. Thin absorbent cores which are common sanitary napkins, baby diapers and incontinence guards, often comprise a compressed, mixed or layered structure of cellulosic fluff pulp and superabsorbent polymers. The size and absorbent capacity of the absorbent core may be varied to suit different product types, such as sanitary napkins for adult incontinent persons or panty liners.
(38) Generally, the core can be of unitary construction, whereby, for example, the manufacturing process can be simplified. The phrase “unitary construction” in the present context is intended to mean that the absorbent core is constructed from essentially one type of material, this being essentially the same material, or essentially the same combination of two or more materials throughout the absorbent core. Variations in density and concentration of the material may occur, but these are limited to those which may be obtained without incorporation of regions which have been formed separately and then physically joined to each other. For example, when the absorbent core comprises a matrix of hydrophilic fibres and superabsorbent material as described above, the relative concentrations of superabsorbent material and fibres may be different in different parts of the core. However, the absorbent core of unitary construction does not comprise layers or laminates of different composition. Likewise, variations in the density or concentration of various components across the longitudinal direction, the transverse direction or the thickness direction of the absorbent core are acceptable, yet the core should not comprise areas or layers of different composition which are formed separately and later joined together.
(39) As shown in
(40) In
(41) The acquisition layer 36 can have different shapes, and can be adapted to suit the shape of the absorbent core. In various embodiments, the acquisition layer 36 extends 1-2 mm beyond the outer edge of the core 6 (preferably around the entire periphery of the core 6). This configuration can provide neat edges at the periphery of the article.
(42) The absorbent core 6 comprises a first region 12, which is designed and arranged such that it is symmetric about the longitudinal centre line A of the article 1. This is important so that the article 1 lies symmetrically on the user's body when in use. The first region 12 may have the same outer contour as the absorbent core 6, as shown in
(43) The first region 12 comprises in the front portion 2 a head portion 13 and two leg portions 15, 16 extending symmetrically about a centre line A and in a longitudinal direction y of the article 1, starting from a leg portion start point a.sub.0 in the crotch portion 3 and extending over a portion of the crotch portion 3 towards separate leg portion endings 17, 18 in the rear portion 4. The outer contour of the head portion 13 is defined by two mirror-imaged substantially convex lines in respect to the longitudinal centre line A. The convex lines converge towards the core rear edge 57 and the first region rear edge 37 so as to define a “neck” for the first region 12, i.e., so as to define the narrowest width M in the transverse direction x for the first portion 12 between first and second first region edge lines 22, 23. The narrowest width M may be at the location of a transition 5, which is an area located between the front portion 2 and the crotch portion 3. Alternatively, the narrowest width M is located in the front portion 2 and the transition 5 is located in the longitudinal direction between the narrowest width M and a transversal line crossing the start point a.sub.0 for leg portions 15 and 16 of the core.
(44) As shown in the drawings, the absorbent core 6 further comprises a second region 24. The leg portions 15 and 16 have facing sides 19, 20, which together with a first region rear edge 37 define an outer contour for the second region 24 of the core 6. The second region 24 comprises a centre region 25 and a rear section 38. The portions of the facing sides that oppose each other in the rear section 38 are denoted with reference numerals 19′ and 20′ in
(45) The minimum width of a rear section, which is limited by the facing sides of the respective leg portions, can be from 5-30 mm and a length can be from 30-110 mm. The relatively wide forward part of the second region and the relatively narrow rearward part of the second region may improve performance of the article because the wider forward part can provide a comfortable material surface in the region of the article in contact with the vulval vestibule, in the crotch region of the article, whilst the narrower rearward part of the second region between the leg portions is adapted to conform to the region between the buttocks. The wider forward part can be raised and can be slightly curved to sit comfortably against the vulval vestibule.
(46) The “crotch point” is defined as a middle point of the centre region 25, which is located in a wetting area centrally in the crotch portion 3 of the article. The wetting area is the area where the liquid is initially expected to hit the article. In connection with articles adapted to absorb blood, such as sanitary napkins, it has been found that the crotch point should be located at the point being in contact with introitus. A longitudinal distance between a transversal line at the transition 5, which can correspond to a line drawn between two points at opposite edges 22, 23 of the first region 12 of the core 6 at the point where the first region 12 has its narrowest width M, and the crotch point is about 63 mm when the user is sitting and about 67 mm when the user is standing, whereby an average distance of 65 mm can be calculated. This distance is indicated by reference sign d.sub.CP in
(47) The facing sides 19, 20 of the respective leg portions 15, 16 converge backwards in the longitudinal direction y such that said distance a.sub.x is reduced from the maximum distance a.sub.1 to a minimum distance a.sub.2 between the rear parts 19′, 20′ of the facing sides.
(48) The second region 24 is at least partially surrounded by the first region 12 and extends between the leg portions 15, 16 in the transverse direction x and in the longitudinal direction y from the leg portion start point a.sub.0 in the crotch portion 3 to a longitudinal endpoint a.sub.l defining the extension of the leg portions 15, 16 in the rear portion 4. The leg portion start point a.sub.0 is located in the centre line A so that a symmetrical leg shape can be provided in each longitudinal portion I and II. A distance a.sub.x between facing sides 19, 20 of the respective leg portions 15, 16 in the transverse direction x varies in the longitudinal direction y. In this way portions having different extensions in the transverse direction are provided to improve the fit and the absorbent properties in the article. The facing sides 19, 20 of the respective leg portions 15, 16 converge backwards towards the article rear edge 47 of the article in the longitudinal direction y such that said distance a.sub.x is reduced from said maximum distance a.sub.1 to a minimum distance a.sub.2. The minimum distance is preferably located outside the wetting area located in the crotch portion and is located in the rear portion 4 of the article 1.
(49) The centre region 25 of the second region 24 is located in the crotch portion 3, and a rear section 38 located in the rear portion 4 of the article 1. The second region 24 is surrounded by the first region 12, except in the first region rear edge 37 area of the core 6. The second region 24 suitably covers from 10-50%, such as from 20-40% of a total area of the core 6. The length of the second region 24 extending along the centre line A between the leg start point a.sub.0 an endpoint a.sub.l in the rear portion 4 may vary greatly depending on the size of the article, but can be, for example, from 80 to 220 mm. The rear section 38 may have a length varying from, for example, 30-110 mm. The centre region 25 may have a length varying from, for example, 50-110 mm. The rear section 38 has a narrower width or extension in the transverse direction x than the centre region 25 or at least a portion of the centre region 25. The rear section 38 can have a lower average density of absorbent material than the centre region 25. Also, the article in the rear section 38 has a lower stiffness than in the first region 12. Alternatively, the centre region 25 and the rear section 38 have substantially the same density. Thus, also the stiffness of the centre region 25 and the rear section 38 may be substantially the same.
(50) The second region 24 which comprises the centre region 25 extending symmetrically about the centre line A, has a longer extension in the longitudinal direction y than in the transverse direction x. Suitably, the centre region has an oval shape or a shape of a parallelogram with edges being located along the centre line A and thus the centre region 25 extends longitudinally and symmetrically about the centre line A. The second region 24 further comprises a longitudinally and symmetrically about the centre line A extending rear section 38. The rear section 38 is in contact with the centre region 25 and can overlap with the centre region 25. Further, the rear section 38 is limited by the facing sides 19, 20 of the respective leg portions 15, 16 and the first region rear edge 37. The facing sides 19′, 20′ adjacent the rear section 38 can be curved (as shown in
(51) Generally, the absorbent core 6 has an asymmetrical shape in the longitudinal extension y, but the first and second longitudinal portions I, II are symmetrical in the transverse extension x about the centre line A. The core 6 may have different shapes, but the circumferential edges 8, 9 of the core 6 define a shape in which a head portion 13 and at least one neck area, i.e., an area with smaller width in the transverse direction x, is located in the front portion 2 or in the transition area 5 of the core 6. In this way, the article 1 can better conform to the body shape in the area where the front portion 2 transitions to the crotch portion 3. Practically this means, i.e., that the article 1 can bend in a transversal direction more easily in the area of the neck portion. Therefore, the front portion 2 and the core head portion 13 can bend towards the user and thus the front portion can better cover the pubic regions of the wearer while the crotch portion 3 is able to locate close to the genital area of a female wearer. Also, the article 1 will better be held in its position during the use. The neck area of the core 6 may be the same where the first region 12 of the core 6 has its narrowest width or it may be distanced from that.
(52) The absorbent article 1 according to the present disclosure may further include a liquid acquisition sheet 36, which acts as a liquid distribution layer. The liquid acquisition sheet 36 is located between the topsheet 30 and the core 6 and is suitably placed on top of the absorbent core 6. The liquid acquisition sheet 36 is adapted to quickly receive and temporarily store discharged liquid before it is absorbed by the absorbent core 6. Such acquisition distribution layers may be composed of, for example, airlaid nonwoven, spunlace nonwoven, high loft nonwoven or foam materials. The nonwoven material may be hydrophilic. A hydrophilic material may be obtained by adding a surfactant.
(53) An air laid nonwoven can be produced with fluff, wood pulp, and here the fluff fibres are dispersed into a fast-moving air stream and condensed onto a moving screen by means of pressure and vacuum. The web can be bonded with resin and/or thermal plastic resin dispersed within the pulp. The web can be thermobonded (by heat), latex bonded (with adhesive) or multibonded (a combination of thermo and latex bonding) or mechanically bonded (high compression and temperature, bonding by hydrogen). The gram mage of the airlaid nonwoven can suitably be from 50 to 100 gsm.
(54) A high loft material is a nonwoven material and may be substantially free from absorbing fibres and superabsorbent material. The high loft nonwoven material may comprise thermoplastic polymer fibres, and may be selected from but not limited to, polyesters, polyamides and polyolefins such as polyethylenes (PE) and polypropylenes (PP) and may be a mixture of any of these. The high loft material refers to low density bulky fabrics, as compared to flat, paper-like fabrics. High loft webs are characterised by a relatively low density. This means that there is a relatively high amount of void space between the fibres. The high loft nonwoven fibrous layer of the present invention may typically have a density below 0.200 g/cc (200 kg/m.sup.3), in particular ranging from 0.015 g/cc to 0.150 g/cc (15 kg/m.sup.3 to 150 kg/m.sup.3), in particular from 0.030 g/cc to 0.100 g/cc (30 to 100 kg/m.sup.3), for example 0.065 g/cc (65 kg/m.sup.3). The average density can be calculated by dividing the basis weight of the high loft layer by its thickness measured at a pressure of 0.5 kPa (according to the test method referred to in PCT International Application No. PCT/SE2017/050612). Normally the thickness of high loft materials is more than about 0.5 mm, such as more than 1 mm or suitably 1.5-2.0 mm, and the solid content is low, usually less than 15% by volume. The high loft nonwoven layer may advantageously be a spunmelt nonwoven. Spunmelt is a generic term describing the manufacturing of nonwoven webs directly from thermoplastic polymers. It encompasses 2 processes and the combination of both: spunlaid (also known as spunbond) nonwoven and meltblown nonwoven. In a spunlaid process, polymer granules are melted and molten polymer is extruded through spinnerets. The continuous filaments are cooled and deposited on to a conveyor to form a uniform web. Some remaining temperature can cause filaments to adhere to one another, but this cannot be regarded as the principal method of bonding. The spunlaid process has the advantage of giving nonwovens greater strength, but raw material flexibility is more restricted. Co-extrusion of second components is used in several spunlaid processes, usually to provide extra properties or bonding capabilities. In meltblown web formation, low viscosity polymers are extruded into a high velocity airstream on leaving the spinneret. This scatters the melt, solidifies it, and breaks it up into a fibrous web. The liquid acquisition sheet material may be of a spunbonded material and may be a spunbond-meltbond-spunbond (SMS) material. The high loft nonwoven layer may in particular have a thickness ranging from 0.30 mm to 2.00 mm, for example 1.0 mm as measured at a pressure of 0.5 kPa (according to the test method referred to in PCT International Application No. PCT/SE2017/050612). The grammage, i.e., basis weight of the high loft material may, for example, range from 15 gsm to 500 gsm, in particular from 30 gsm to 200 gsm, such as 30-90 gsm, for example 64 gsm.
(55) According to a further variant, the liquid acquisition sheet 36 is a spunlace, also referred to as spunbond, nonwoven material. A spunlace nonwoven product is derived from a process of entangling a web of loose fibres through multiple rows of jets of water at high pressure; this process entangles the fabrics and interlinks the fibres. There are several terms for spunlace nonwoven fabric or spunlaced, such as jet entangled, needled, hydroentangled or hydraulic, but the term spunlace or spunlaced is the most popular in the nonwoven industry. The raw material for the acquisition sheet can be polypropylene (PP), polyethylene (PE) polyester (PET), polyamide (PA), cellulosic fibres or a combination of these and different weights and compositions are possible, such as viscose, polyester, cotton, nylon and microfiber, wherein viscose is the most commonly used raw material. Thus, if a combination of different fibres is used, this can be a mixture of fibres from different polymers, although each fibre can also include different polymers (e.g., PP/PE bi-component fibres or PP/PE copolymers). Where appropriate, the plastic film can consist of PE or PP, PET, PLA, or amyl (or, for that matter, any other thermoplastic polymer), or a mixture or copolymers of the aforementioned polymers. The spunlace material usually comprises polypropylene or polyethylene fibres which provide for optimal comfort for the nonwoven material. Other suitable fibres for making the nonwoven material are, for example, natural fibres such as bamboo, cotton, and flax. The grammage of the spunlace nonwoven material can be typically from 30-80 gsm.
(56)
(57) In alternative embodiments, and as shown in
(58) In embodiments comprising an outer core 120, as illustrated in
(59) In yet another embodiment (not shown in the drawings), a liquid acquisition material can be provided covering only a portion of the core, for example a longitudinal central portion of the core. In embodiments in which a liquid acquisition material is provided across over only a portion of the core, the acquisition material may cover at least central region 25. Moreover, in an embodiment in which the liquid acquisition material does not extend beyond an outer edge of the core, the core may comprise a relatively soft outer region 120, as illustrated in
(60) Referring now to both
(61) As shown in
(62) As shown in
(63) Returning now to
(64) Although not shown in the drawings, the slit can extend from a start point located in the centre line A in the rear portion 4 between the first region rear edge 37 and the core rear edge 57. The slit can extend up to the leg start point a.sub.0 in the crotch portion 3. In one embodiment, the slit does not extend to the front portion 2 of the article 1, since the front portion 2 may bend along a transverse bending axis. In this way the front portion 2 will have maximal extension in the transverse direction x and will thus be able to cover the pubic region of the user. By providing the slit so that it extends at least partially along the length of the rear section 38, a certain fold in the rear section is essentially promoted and the comfort of the hygiene article is improved. Therefore, also undesired twisting, bunching or folding of the article between the buttocks is reduced. Folding of the rear section 38 in a controlled way by means of the slit between the user's buttocks also promotes secure fit, as transverse and longitudinal movement of the article during wear is reduced. The different densities in the first region 12 and at least a portion of the second region 24 and the optional slit in the acquisition layer (where present) cooperate in order to provide the article 1 with a form that follows the contours of the wearer's body even more closely. More specifically, the article 1 is provided with a form that molds towards labia during use. The side areas, i.e., outer edge regions of the article 1 comprising the acquisition layer 36 can provide soft edges to the article which increases comfort. Alternatively, as described above, an outer core region can be provided, which surrounds the first region 12 of the core 6, to provide the article with soft edges.
(65) Furthermore, referring still to
(66) In addition, the higher average density of the first region 12 implies that it has great liquid-spreading capacity for rapid spreading of bodily fluid received from the wearer over the core 6. The higher average density of the first region 12 in the head part 13 also promotes stability, i.e., it promotes that the head part 13 remains out-stretched and that wrinkle formation is inhibited.
(67) A suitable technique for manufacturing the absorbent cores of the present disclosure is mat-forming through an air-laying process. In the process, an air-permeable mould is provided. Fibrous material is air-laid into the mould and the mould is filled, whereby an absorbent core is produced in with a desired amount of fibrous material.
(68) After the absorbent core 6 is produced, it can be pattern-compressed so that an absorbent core having regions with different densities is produced. Compressing may take place using any known means. The average density of the fibrous material in the low-compressed or non-compressed absorbent core corresponds to the average density of the absorbent core in the regions of lower average density, i.e., the second region 24. The absorbent core outside these regions, i.e., in the first region 12, is then compressed while within these regions, the core remains uncompressed.
(69) Thus, the first region of the core is compressed more than the second region. Alternatively, or additionally, the first region is embossed to solely provide the higher compression or to further increase compression grade obtained by compression. If the compression and embossing are separate steps, the step of embossing of an embossing pattern can be performed simultaneously or subsequently with the compression to areas providing the first region. The embossing pattern is suitably visible through the top sheet. The compression and embossing can be performed through the topsheet or the backsheet side of the core.
(70) Turning now to
(71) Similarly to the first pair of rear compression lines, the second pair of rear compression lines comprises a left compression line front endpoint PF.sub.L2 and an associated rear endpoint PR.sub.L2. The second right compression lines also comprises a front endpoint PF.sub.R2 and an associated rear endpoint PR.sub.R2.
(72) In the embodiment shown in
(73) The second pair of rear compression lines L2, R2 curve away from each other. At their closest point, the second left and right rear compression lines L2, R2 are separated from each other by a distance G4min, measured in a transverse direction x. The minimum distance G4min between the second left and right rear compression lines L2, R2 is between the rear endpoints PR.sub.L2, R2. The maximum distance G4max between the second left and right rear compression lines L2, R2 is, in the transverse direction x, between the front endpoints PF.sub.L2, R2 of the second left and right rear compression lines. The first left and right compression lines are arranged so that the distance between symmetrically opposite points on the respective compression lines increases continuously as the compression lines L1, R1 extend in the forward direction. Moreover, the first left and right rear compression lines L1, R1 are arranged such that they are convex with respect to the centre line A. Thus, the left and right rear compression lines L1, R1 become increasingly divergent as they extend in the forward direction.
(74) As shown in
(75) The curvature of the first and second pairs of rear compression lines distributes the forces exerted on the article by the user's body and clothing to provide controlled and preferential folding of the article in the rear portion 4 of the article 1.
(76)
(77)
(78) The second, forward pair L2, R2 of rear compression lines have a longitudinal extent between the front and rear endpoints of G2, and a minimum separation, between the rear endpoints, in the transverse direct x, of G4.sub.min, and a maximum separation, between the front endpoints, in the transverse direction x, of G4.sub.max.
(79) In the embodiment shown in
(80) Although it is preferred that the rearward pair of compression lines is curved when the article comprises one pair of rear curved compression lines and one straight pair of rear compression lines, the skilled person will understand that the present invention also incorporates embodiments in which the rearward pair of rear compression lines are straight, and the forward pair of rear compression lines are curved. In all embodiments comprising multiple pairs of rear compression lines, it is preferred that the forward pair have a shorter longitudinal extent than the rearward pair.
(81) As shown in
(82) As shown in
(83) As shown in
(84) The second (right) front compression line 102 is configured as a mirror image of the left front compression line 101, as shown in
(85) As shown in
(86) The minimum distance D1 can be at least 1 mm, more preferably at least 2 mm and, more preferably at least 3 mm. In preferred embodiments, the minimum distance D1 is less than 20 mm, more preferably less than 10 mm.
(87) By providing compression lines along which the article can fold or deform when compressed, the position of the folds and creases can be controlled in such a manner that the risk of leakage is minimized. However, the position of compression lines should be carefully considered to avoid that other properties of the article are not unduly compromised. For example, the compression lines should not weaken the structure of the article to such a degree that it becomes prone to tearing. Moreover, the compression lines should not impede the distribution of fluid throughout the article in such a manner that increases the likelihood of leaks.
(88) In addition to the front compression lines shown in
(89) The curved rear compression lines L1, R1 (and any additional compression lines) described herein may be provided by means of groove or line compressing the core 6 and optionally a liquid acquisition sheet and/or topsheet with high pressure compression from the topsheet or backsheet side of the article. The backsheet of the article can be retained unacted and the liquid impermeability of the backsheet is not affected and can be maintained. Methods of manufacturing the above described article according to such means are intended to fall within the scope of the present invention.
(90)
(91) As illustrated in
(92) However, although all exemplary embodiments illustrated in the drawing comprise wings 32, the skilled person will appreciate that this is not essential to the definition of the present invention, and that the absorbent article 1 may be provided in variants that do not comprise any wings.
(93) Furthermore, in an alternative embodiment, the absorbent article 1 may only comprise a backsheet 31, i.e., no topsheet. Additionally, the absorbent core 6 of the absorbent article may be wrapped in a single coversheet which can act as both inner and backsheet.
(94) The absorbent article 1 defined above may comprise any attachment means known in the art to allow fastening to undergarments of a wearer. Such means may include a coating of adhesive or friction coating on the garment-facing surface of the article. Furthermore, the article 1 according to the present invention may comprise, as above described, attachment flaps (“wings”) which extend in the transverse direction of the article 1 and are intended to be arranged around the crotch portion on the briefs of the wearer. It is however important that the nature and placement of such attachment means does not significantly interfere with the function of the article 1 in use.
(95) Although the above discussion has been exemplified through a sanitary napkin, the present invention is also applicable to other absorbent articles such as diapers, incontinence pads or panty-liners. For instance, application of the present invention to diapers would provide similar benefits in terms of comfort, fit and leakage-prevention.
(96) The present invention should not be considered as limited by the above description; rather the scope and limitations of the present invention are defined by the enclosed claims.