Absorbent hygienic article for absorbing body fluids

Abstract

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

Claims

1. An absorbent hygienic article for absorbing body fluids, the article comprising a liquid absorbent top layer and a backing layer, the top layer and the backing layer being made from roll materials and being joined together, wherein the top layer consists of a cellulosic fibrous web, the fibres in the cellulosic fibrous web consisting of a mixture of cellulose fibres, the mixture comprising cellulose pulp fibers, and at least one of regenerated cellulose fibres and natural cellulose staple fibres, the cellulosic fibrous web being a foam-formed, hydroentangled cellulosic fibrous web.

2. An absorbent hygienic article according to claim 1, wherein the regenerated cellulose fibres and/or the natural cellulose staple fibres are staple fibres having a length within the range of from 2 to 20 millimeter and a linear 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 includes viscose fibres.

4. An 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 top layer has a basis weight of from 30 gsm to 100 gsm.

6. An absorbent hygienic article according to claim 1, wherein the cellulosic fibrous web has a bulk in the range of 7.5 to 11 cm.sup.3/g.

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

8. An absorbent hygienic article according to claim 1, wherein the cellulosic fibrous web 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.

9. An absorbent hygienic article according to claim 1, wherein the absorbent hygienic article has a liquid spreading capacity in a cross machine direction of the cellulosic fibrous web 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.

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

11. An absorbent hygienic article according to claim 1, wherein a sample of the cellulosic fibrous web having a length in the machine direction of 100 millimeters and a width in the cross machine direction of 50 millimeters and a basis weight of 50 gsm to 70 gsm has a wet area of 3500 mm.sup.2 or more as measured according to the test method as disclosed herein.

12. An absorbent hygienic article according to claim 1, wherein the top layer and the backing layer are the only constituent layers of the absorbent hygienic article.

13. An absorbent hygienic article according to claim 1, wherein the absorbent hygienic article is a panty liner.

14. An absorbent hygienic article according to claim 1, wherein the absorbent hygienic article is an underwear protector, an underarm protector, a bib, a seat cover, a place mat, under pants, or a bed protector.

15. An absorbent hygienic article according to claim 1, wherein a user-facing surface of the absorbent hygienic article is provided with 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.

16. An absorbent hygienic article according to claim 1, wherein a sample of the cellulosic fibrous web having a length in the machine direction of 100 millimeters and a width in the cross machine direction of 50 millimeters and a basis weight of 50 gsm to 70 gsm has a wet area of 4000 mm.sup.2 or more as measured according to the test method as disclosed herein.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The absorbent 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; and

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

DETAILED DESCRIPTION

(4) 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. Furthermore, the absorbent hygienic article as disclosed herein may be any type of absorbent hygienic article where only a limited amount of absorbency is required such as a panty liner for male or female users, an under-arm protector, a bib, a seat cover, a place mat, under panties, or a bed protector.

(5) The absorbent hygienic article 1 for absorbing body fluids which is shown in FIG. 1 is a panty liner comprising a liquid absorbent top layer and backing layer 3. The top layer 2 and the backing layer 3 are made from roll materials and are joined together, such as by adhesive, ultrasonic welding or mechanical welding using embossing and pressure.

(6) The top layer 2 is constituted by a cellulosic fibrous web 4, as disclosed herein. Accordingly, the fibres in the cellulosic fibrous web 4 are constituted by a mixture of cellulose fibres. The fibre mix comprises regenerated cellulose fibres, such as viscose fibres and cellulose pulp fibres such as wood pulp fibres. The cellulosic fibrous web is a foam-formed, hydroentangled cellulosic fibrous web. The regenerated cellulose fibres may be staple fibres, as disclosed herein.

(7) The backing layer 3 is a liquid barrier layer which is arranged on the surface of the panty liner 1, which is intended to face away from the wearer of the panty liner 1 during use of the panty liner 1, also referred to herein as the garment-facing surface 5 of the panty liner 1. The garment-facing surface 5 is opposite a wearer-facing surface 6. The backing layer 3 is preferably fluid impermeable. However, liquid barrier materials which are only resistant to fluid penetration may be used for the backing layer 3, particularly as only small amounts of body fluid are expected to be taken up by the absorbent hygienic articles as disclosed herein. The backing 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 as disclosed herein. The backing layer 3 may be breathable, implying that air and vapor may pass through the backing layer 3. It may be preferred that the backing layer is made from renewable raw materials.

(8) As is shown in FIG. 2, 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.

(9) The fastening member 8 may be applied over the full outer surface of the the backing 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.

(10) The absorbent hygienic article 1 as disclosed herein is preferably thin and inconspicuous, the top layer preferably having a basis weight of at most 100 gsm, such as from 30 gsm to 100 gsm.

(11) The absorbent hygienic article 1 which is shown in FIGS. 1 and 2 is provided with an embossed pattern in the form of a first pair of line embossings 11, 12 arranged along the longitudinal side edges 13, 14 of the absorbent hygienic article 1. A second pair of longitudinally extending line embossings 15, 16 are arranged centrally between the first pair of line embossings 11, 12. Line embossings generally promote fluid distribution along the lines and counteract fluid distribution perpendicular to the embossings.

(12) A generally V-shaped embossing 17 is arranged at the front end edge 19 of the absorbent hygienic article 1 and an embossed flower 18 is arranged at the rear end edge 20 of the absorbent hygienic article 1. The second pair of line embossings 15, 16 are arranged to promote liquid spreading in the longitudinal direction of the absorbent hygienic article 1. The first pair of line embossings 11, 12 are arranged to retard liquid spreading to the longitudinal side edges 13, 14 of the absorbent hygienic article 1. The embossings 17, 18 which are placed at the end edges 19, 20 of the article have a fluid retarding function but are also intended to enhance the visual appearance of the absorbent hygienic article 1.

(13) The absorbent hygienic article 1 may alternatively or in addition to embossings comprise functional and/or appearance enhancing print. The embossings which are shown in the FIGS. 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

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

(15) Sample Preparation

(16) 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.

(17) Determining Basis Weight and Density of a Web Sample

(18) 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).

(19) 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.

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

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

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

(23) Determining Spreading Distance and Rewet

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

(25) 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 50×100 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.

(26) 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.

(27) The sample is subjected to three 0.5 ml doses of AMF (i.e. 1.5 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.

(28) 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.

(29) 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.

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

(31) Tested Samples

(32) S-1 (Reference sample): 70 gsm spunlace formed from a fibre blend of 35% viscose fibres, 56% polyester fibres (PET) and 9% polylactide acid fibres (PLA).

(33) S-2: A foam-formed hydroentangled cellulosic fibrous web material having a basis weight of 50 gsm.

(34) S-3: a two-layer foam-formed hydroentangled cellulosic fibrous web comprising a first lamina of 20 gsm foam-formed cellulosic fibrous web material and a second lamina of 50 gsm-foam formed cellulosic fibrous web material which were individually hydroentangled before being combined into a single web.

(35) S-4: a two-layer foam-formed cellulosic fibrous web comprising a first lamina of 20 gsm foam-formed cellulosic fibrous web material and a second lamina of 50 gsm foam-formed cellulosic fibrous web material which were hydroentangled together, after having been combined into a single web.

(36) The cellulosic fibrous webs used in samples S-2 to S-4 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.

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

(38) TABLE-US-00001 Basis weight Bulk Spreading CD/width [mm] after Spreading MD/length [mm] after [g/m.sup.2 (gsm)] [cm.sup.3/g] Rewet [g] 1.sup.st, 2.sup.nd and 3.sup.rd liquid insult 1.sup.st, 2.sup.nd and 3.sup.rd liquid insult S-1 69 12.3 1.1 28 38  47  42 52 63 Ref. S-2 52 10.1 0.7 45 50* 50* 60 78 95 S-3 72 10.1 0.6 36 48  50* 48 70 85 S-4 74 8.4 0.4 38 50* 50* 50 71 90 *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.

(39) As can be seen in Table 1, all the samples S-2 to S-4 which are cellulosic fibrous web materials according to the invention as disclosed herein have excellent rewet and liquid spreading properties. It is noted that the conventional polyester/viscose material which was used as the reference had considerably higher rewet than all the samples according to the invention, including the S-2 sample having a lower basis weight than the other samples.