Absorbent hygienic article for absorbing body fluids

Abstract

An absorbent hygienic article for absorbing body fluids, the article including a liquid permeable topsheet, a backing layer and an absorbent core arranged between the topsheet and the backing layer, the topsheet and the backing layer being made from roll materials. The topsheet or an absorbent layer in the absorbent core is constituted by a cellulosic fibrous web, the fibres in the cellulosic fibrous web being constituted by a mixture of cellulose fibres including regenerated cellulose fibres or natural cellulose staple fibres and cellulose pulp fibres, the cellulosic fibrous web being a foam-formed, hydroentangled fibrous web.

Claims

1. An absorbent hygienic article for absorbing body fluids, the article comprising a liquid permeable topsheet, a backing layer and an absorbent core arranged between the topsheet and the backing layer, the topsheet and the backing layer being made from roll materials, wherein the topsheet is constituted by a cellulosic fibrous web, the fibres in the cellulosic fibrous web being constituted by a mixture of cellulose fibres comprising regenerated cellulose fibres or natural cellulose staple fibres and cellulose pulp fibres, the cellulosic fibrous web being a foam-formed, hydroentangled fibrous web or in that an absorbent layer in the absorbent core is constituted by a cellulosic fibrous web, the fibres in the cellulosic fibrous web being constituted by a mixture of cellulose fibres comprising regenerated cellulose fibres or natural cellulose staple fibres and cellulose pulp fibres, the absorbent fibrous web being a foam-formed, hydroentangled fibrous web.

2. An absorbent hygienic article according to claim 1, wherein the regenerated cellulose fibres or the natural cellulose staple fibres are staple fibres having a length within the range of from 2 to 20 millimeter, and a fibre density in the range of from 0.3 to 3 dtex.

3. An absorbent hygienic article according to claim 1, wherein the mixture of cellulose fibres is a mixture of cellulose pulp fibres and viscose fibres.

4. A absorbent hygienic article according to claim 1, wherein the mixture of cellulose fibres is constituted by 2 to 50% by weight of regenerated cellulose fibres or natural cellulose staple fibres based on a total weight of the mixture of cellulose fibres.

5. An absorbent hygienic article according to claim 1, wherein the article has a rewet of less than 1 gram as measured according to the method disclosed herein.

6. An absorbent hygienic article according to claim 1, wherein the absorbent core comprises superabsorbent material.

7. An absorbent hygienic article according to claim 1, wherein the backing layer is constituted by renewable raw materials.

8. An absorbent hygienic article according to claim 1, wherein the absorbent hygienic article is a pantiliner, an incontinence protector, a sanitary napkin or an absorbent insert.

9. An absorbent hygienic article according to claim 1, wherein the absorbent hygienic article is a diaper.

10. An absorbent hygienic article according to claim 1, wherein a user-facing surface of the absorbent hygienic article web is provided with with a pattern, the pattern being an embossed pattern, a dimpling pattern, a printed pattern or a combination of one or more of an embossed pattern, a dimpling pattern, and a printed pattern.

11. An absorbent hygienic article for absorbing body fluids, the article comprising a liquid permeable topsheet, a backing layer and an absorbent core arranged between the topsheet and the backing layer, the topsheet and the backing layer being made from roll materials, wherein the topsheet is constituted by a cellulosic fibrous web, the fibres in the cellulosic fibrous web being constituted by a mixture of cellulose fibres comprising regenerated cellulose fibres and/or natural cellulose staple fibres and cellulose pulp fibres, the cellulosic fibrous web being a foam-formed, hydroentangled fibrous web.

12. An absorbent hygienic article according to claim 11, wherein the topsheet has a basis weight in the range of from 10 to 30 gsm.

13. An absorbent hygienic article according to claim 12, wherein the absorbent layer has a bulk in the range of from 8 to 10 cm.sup.3/g.

14. An absorbent hygienic article according to claim 11, wherein an absorbent layer in the absorbent core is constituted by a cellulosic fibrous web, the fibres in the cellulosic fibrous web being constituted by a mixture of cellulose fibres comprising regenerated cellulose fibres or natural cellulose staple fibres and cellulose pulp fibres, the absorbent fibrous web being a foam-formed, hydroentangled fibrous web, the absorbent layer having a basis weight in the range of 30 to 150 gsm.

15. An absorbent hygienic article according to claim 14, wherein the absorbent layer is arranged in direct contact with the topsheet.

16. An absorbent hygienic article according to claim 11, wherein the topsheet has a bulk in the range of from 8 to 17 cm.sup.3/g.

17. An absorbent hygienic article according to claim 11, wherein the absorbent hygienic article has a liquid spreading capacity in a machine direction of the cellulosic fibrous web of 75 millimeters or more as measured after three insults of test liquid in accordance with the test method disclosed herein.

18. An absorbent hygienic article according to claim 11, wherein the absorbent hygienic article has a liquid spreading capacity in a cross machine direction of the absorbent hygienic article of 30 millimeters or more as measured after a first insult of test liquid and of 45 millimeters or more as measured after two insults of test liquid, the measurements being made in accordance with the test method disclosed herein.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The hygienic articles as disclosed herein will be further explained hereinafter by means of non-limiting examples and with reference to the appended drawings wherein:

(2) FIG. 1 shows a panty liner;

(3) FIG. 2 shows a cross-section taken along the line II-II through the panty liner in FIG. 1;

(4) FIG. 3 shows an alternative cross-section taken along the line III-III through the panty liner in FIG. 1; and

(5) FIG. 4 shows a further alternative cross-section taken along the line IV-IV through the panty liner in FIG. 1.

DETAILED DESCRIPTION

(6) It is to be understood that the drawings are schematic and that individual components or features, such as layers of material are not necessarily drawn to scale. The panty liner shown in the figures is provided as an example only and should not be considered limiting to the invention as disclosed herein. In particular, it is to be understood that shape and dimensions are non-essential features of the invention and may be varied within the scope of the claims. In the following the claimed absorbent hygienic article is described with reference to a panty liner. As set out herein, the claimed invention is applicable to any other type of absorbent hygienic article comprising a topsheet, a liquid barrier layer and an absorbent core arranged between the topsheet and the liquid barrier layer. The absorbent hygienic articles as disclosed herein are intended for being at least partly placed in the crotch portion of a user of the absorbent hygienic article for absorbing blood, vaginal discharges, urine, feces, etc. The absorbent hygienic articles include sanitary napkins, diapers for children and adults, incontinence protectors, etc.

(7) The absorbent hygienic article 1 which is shown in FIGS. 1 and 2 is a panty liner comprising a liquid-permeable topsheet 2, arranged on the surface of the absorbent hygienic article 1 which is intended to face towards a user during use. The liquid-permeable topsheet 2 is constituted by a cellulosic fibrous web, the fibres in the cellulosic fibrous web being constituted by a mixture of cellulose fibres comprising regenerated cellulose fibres and/or natural cellulose staple fibres and cellulose pulp fibres, the absorbent fibrous web being a foam-formed, hydroentangled fibrous web.

(8) The absorbent hygienic article 1 further comprises a liquid barrier layer 3, arranged on the surface of the absorbent hygienic article 1, which is intended to face away from the user during use, also referred to herein as the garment-facing surface of the absorbent hygienic article 1. The liquid barrier layer 3 is preferably fluid impermeable. However, liquid barrier layer materials that are only resistant to fluid penetration may be used particularly in instances where relatively small amounts of body fluid are expected to be taken up by the absorbent hygienic article as disclosed herein. The liquid barrier layer 3 may be a thin, flexible, liquid impermeable plastic film, but liquid impermeable nonwoven materials, liquid impermeable foams and liquid impermeable laminates are also contemplated for the articles disclosed herein. The liquid barrier layer 3 may be breathable, implying that air and vapor may pass through the liquid barrier layer. Furthermore, the liquid barrier layer 3 may have an outer, garment-facing surface of a textile material such as nonwoven. Further, it may be preferred that the backing layer is made from renewable raw material.

(9) An absorbent core 4 is arranged between the topsheet 2 and the liquid barrier layer 3. In the panty liner 1 which is shown in the FIGS. 2 and 3, the absorbent core 4 is shown as a single cellulosic absorbent layer 4′ which is constituted by a mixture of cellulose fibres comprising regenerated cellulose fibres and/or natural cellulose staple fibres and cellulose pulp fibres, the absorbent fibrous web being a foam-formed, hydroentangled fibrous web. The cellulosic absorbent layer 4′ is arranged immediately inside the topsheet 2 and in direct contact and fluid communication with the topsheet 2.

(10) In applications where more absorbency is needed such as in larger panty liners, sanitary napkins, diapers, incontinence protectors, incontinence garments, etc. the absorbent hygienic article may comprise further absorbent layers and components, as set out herein.

(11) An example of such an absorbent hygienic article is shown in FIG. 4 where an additional absorbent layer 4″ is arranged beneath the cellulosic absorbent layer 4′.

(12) Such additional absorbent layer or layers may comprise superabsorbent material, as set out herein. The superabsorbent material may be in particle form, as superabsorbent foam, superabsorbent fibres, etc. as known in the art. Superabsorbent particles may be blended with cellulose fibres such as cellulose pulp fibres.

(13) In the panty liner 1 which is shown in FIGS. 2 and 4 the topsheet 2 and the liquid barrier layer 3 are directly joined to each other in an edge seal 5 extending around the periphery of the absorbent core 4. The edge seal 5 is formed laterally outside the peripheral edge of the absorbent core 4. Joining of the topsheet 2 and the liquid barrier layer 3 can be achieved using any known technique or combination of techniques suitable for the purpose, such as gluing, thermobonding, ultrasonic welding or heat embossing.

(14) As set out herein, such a direct seal between the topsheet 2 and the liquid barrier layer 3 is an optional feature of the claimed invention. Hence, the topsheet 2 and the liquid barrier layer 3 may be indirectly joined to each other by being directly joined to the absorbent core, or may be formed by a single sheet of material which is wrapped around the absorbent core. In the absorbent hygienic article shown in FIG. 3, all of the topsheet 2, the liquid barrier layer 3 and the absorbent core 4 are coextensive and together define the peripheral edge 6 of the absorbent hygienic article 1, the peripheral edge 6 of the absorbent hygienic article 1 defining the planar shape of the absorbent hygienic article 1.

(15) In the absorbent hygienic article 1 which is shown in FIG. 3, the edge seal 5 joins all of the topsheet 2, the liquid barrier layer 3 and the absorbent core 4. The edge seal 5 in FIG. 3 is a compression bond which may be made by heating and embossing.

(16) The edge seals 5 as disclosed herein may be continuous or discontinuous bonds, as desired.

(17) The components in the absorbent hygienic article 1 may be connected to each other by conventional means such as construction adhesive, heat bonding, ultrasonic bonding, mechanical welding using embossing and pressure, etc. It may not be necessary to bond internal components of the absorbent article to each other by special bonding means. Accordingly, it may suffice that such components are held together by frictional forces.

(18) As is shown in FIGS. 2-4, the absorbent hygienic article 1 has a fastening member 8 on the garment-facing surface 5 of the absorbent hygienic article 1. The fastening member 8 is provided for allowing the absorbent hygienic article 1 to be fastened in the crotch portion of a pair of underpants or a hygienic pant and may e.g. be an adhesive fastening member, a friction fastener member or a hook-type fastener member as known in the art. The fastening member 8 may be protected by a release liner (not shown) during packaging and transport. The release liner is removed to expose the fastening member 8 before the absorbent hygienic article 1 is applied in the crotch portion of a pair of underpants. The fastening member 8 may alternatively be protected by a wrapper, also commonly referred to as a “single pack”, which is releasable attached to the fastening member 8 and which is removed at the same time as the absorbent hygienic article 1 is taken out of the wrapper. The fastening member 8 may be applied over the full outer surface of the the liquid barrier layer 3 or may be applied only in one or more selected areas of the outer surface of the liquid barrier layer 3. The fastening member 8 is an optional feature of the absorbent hygienic article.

(19) The absorbent hygienic article 1 which is shown in FIG. 1 is provided with an embossed pattern in the form of a plurality of line embossings 11 which are arranged in the topsheet 2. The embossings 11 are optional features of the absorbent hygienic articles as disclosed herein and are not shown in the cross-sectional views in FIGS. 2-4. The embossings 11 may extend from the outer surface of the absorbent hygienic article 1 downward into the underlying absorbent core 4 such that the fibrous structure of the topsheet 2 and optionally also the absorbent core 4 is compressed within the areas of the embossings. Line embossings generally promote fluid distribution along the lines and counteract fluid distribution perpendicular to the embossings.

(20) The absorbent hygienic article 1 may alternatively or in addition to embossings comprise functional and/or appearance enhancing print. The embossings 11 which are shown in FIG. 1 are optional to the absorbent hygienic article as disclosed herein. It is also to be understood that the embossings are not limited either to the number, shape or positioning shown in FIG. 1. Furthermore, if using embossings, they may be functional, appearance enhancing or a combination of functional and appearance enhancing embossings.

EXAMPLES AND DESCRIPTION OF TEST METHODS

(21) Absorbent articles or isolated layers of the cellulosic fibrous web as disclosed herein can be subjected to testing according to the methods described herein.

Sample Preparation

(22) Before testing, single articles or single layer web samples should rest flat and exposed for 24 hours in a stable laboratory environment set to 23° C. and 50% relative humidity. All subsequent testing should then be made in this same environment.

Determining Basis Weight and Density of a Web Sample

(23) The web sample is weighed to the third decimal. The area of the sample is then determined, and basis weight is obtained by dividing the sample weight by the sample area. Basis weight is reported in the unit g/m.sup.2 (gsm).

(24) Web thickness is measured under a pressure of 0.5 kPa. A suitable thickness gauge should have an accuracy of 0.01 mm. Pressure is exerted from a square foot measuring 50×50 mm. The foot is gently lowered onto the sample, and a thickness value is read after 5 seconds.

(25) Bulk is obtained by dividing the sample volume by the sample weight and should be reported in the unit cm.sup.3/g.

(26) Density is obtained by dividing the sample weight by the sample volume and should be reported in the unit kg/m.sup.3.

(27) A mean value is reported from measurements of ten representative samples.

Determining Spreading Distance and Rewet

(28) An artificial menstrual fluid (AMF) according to the French standard AFNOR Q34-018 is used when testing.

(29) For the spreading and rewet determinations, the sample should rest flat on a laboratory bench. Folded absorbent articles are unfolded, and carefully stretched flat. If testing a fibrous web in isolation, the web should be cut or punched to a rectangle measuring 50×150 mm. The length direction of the sample should coincide with the machine direction (MD) of the web. A smooth, liquid impermeable polyethylene film should be placed underneath the fibrous web.

(30) The center point of the sample is identified (the point where the longitudinal centerline crosses the transverse centerline). AMF is introduced via a tube (internal diameter about 3 mm) connected to an automatic dispenser. The orifice of the tube is positioned perpendicular to the center point, with about 5 mm distance to the sample surface.

(31) The sample is subjected to three 1.0 ml doses of AMF (i.e. 3.0 ml in total), introduced at a rate of 15 ml/min. When a dose has been absorbed (i.e. when there is no more free fluid on the sample surface), a stopwatch is started, and the next dose is introduced after 15 minutes.

(32) Spreading length is measured 5 seconds after each dose has been absorbed. A ruler is placed along the longitudinal and transverse centerlines of the sample, and the extension of the wet area in the fibrous web (or article top layer) is determined. AMF that possibly spreads longer in the lateral side regions along the respective centerlines (such as in grooves or densified bonding patterns) is disregarded.

(33) Rewet is measured 15 minutes after the third (last) dose has been absorbed. A stack of five pre-weighed filter papers (90×120 mm, 440 g/m.sup.2 per sheet, Quality 167 from Munktell Ahlstrom or equivalent filter papers) is centered on top of the sample. A 5.5 kg weight with bottom dimension 90×120 mm (exerting a pressure of 5 kPa) is gently lowered on top of the stack. After 15 seconds the weight is removed, the filter papers are weighed, and AMF rewet is determined.

(34) Mean values are reported from measurements of ten representative samples.

Tested Samples

(35) S-1: A topsheet of 23 gsm polypropylene spunbond nonwoven with a bulk of 10 cm.sup.3/g and an absorbent core layer formed from 140 gsm airlaid pulp fibres with a bulk of 9.8 cm.sup.3/g.

(36) S-2: A topsheet of foam-formed hydroentangled cellulosic fibrous web material having a basis weight of 20 gsm and a bulk of 11.8 cm.sup.3/g and an absorbent core layer formed from 140 gsm airlaid pulp fibres and having a bulk of 9.7 cm.sup.3/g.

(37) S-3: A topsheet of 23 gsm polypropylene spunbond nonwoven with a bulk of 9.9 cm.sup.3/g and an absorbent core layer formed from a foam-formed hydroentangled cellulosic fibrous web having a basis weight of 100 gsm and having a bulk of 6.4 cm.sup.3/g.

(38) S-4: A topsheet of 23 gsm polypropylene spunbond nonwoven having a bulk of 10 cm.sup.3/g and an absorbent core layer formed from a foam-formed hydroentangled cellulosic fibrous web having a basis weight of 150 gsm and having a bulk of 5.9 cm.sup.3/g.

(39) S-5: A topsheet of foam-formed hydroentangled cellulosic fibrous web material having a basis weight of 20 gsm with a bulk of 15 cm.sup.3/g and an absorbent core layer formed from a foam-formed hydroentangled cellulosic fibrous web having a basis weight of 100 gsm and having a bulk of 6.7 cm.sup.3/g.

(40) S-6: A topsheet of foam-formed hydroentangled cellulosic fibrous web material having a basis weight of 20 gsm with a bulk of 16.6 cm.sup.3/g and an absorbent core layer formed from a foam formed hydroentangled cellulosic fibrous web having a basis weight of 150 gsm and having a bulk of 5.6 cm.sup.3/g.

(41) S-7: A topsheet of 23 gsm dry creped tissue with a bulk of 8.1 cm.sup.3/g and an absorbent core layer formed from 140 gsm airlaid pulp fibres with a bulk of 10.0 cm.sup.3/g.

(42) S-8: A topsheet of 35 gsm philic cotton spunlace nonwoven with a bulk of 18.4 cm.sup.3/g and an absorbent core layer formed from 140 gsm airlaid pulp fibres with a bulk of 10.1 cm.sup.3/g.

(43) The cellulosic fibrous webs used in samples S-2 to S-6 were all produced in the same manner with the foam-forming process disclosed in WO 2018/065668 A1. All samples had the same fibre composition of 15% viscose, commercial 1.7 dtex 10 mm Danufil, Kelheim, and 85% unrefined bleached softwood kraft pulp. All samples were hydroentangled on the same equipment under comparable conditions.

(44) The results of the tests are set out in Table 1.

(45) TABLE-US-00001 Spreading CD/width Spreading MD/length [mm] after 1.sup.st, 2.sup.nd [mm] after 1.sup.st, 2.sup.nd Rewet [g] and 3.sup.rd liquid insult and 3.sup.rd liquid insult S-1 1.5 35 50 50 33 49 58 Ref. S-2 1.7 30 45 50 32 46 59 S-3 0.3 50 50 50 56 80 106 S-4 0.02 45 50 50 48 70 96 S-5 0.51 45 50 50 58 80 104 S-6 0.24 40 50 50 50 68 90 S-7 1.46 31 47 50 30 41 49 Ref. S-8 1.62 24 36 48 34 45 58 Ref. **a liquid spreading value of 50 mm in the CD/width direction is an indication that liquid has spread in the width direction of the sample all the way to the longitudinal side edges of the sample.

(46) As can be seen in Table 1, all the samples S-3 to S-6 which contain the foam-formed, hydroentangled cellulosic fibrous web materials disclosed herein as a core layer have excellent rewet and liquid spreading properties. It is noted that the samples S-1, S-2, S7 and S-8 having a conventional hydrophilic topsheet, a tissue topsheet or a conventional airlaid core layer had considerably higher rewet than the other samples.