WO2009157835A1

WO2009157835A1 - Absorbent article with improved fit and improved capability to stay in place during use

Info

Publication number: WO2009157835A1
Application number: PCT/SE2008/050799
Authority: WO
Inventors: Rozalia Bitis; Ingrid Stjernholm; Pernilla Lundahl
Original assignee: Sca Hygiene Products Ab
Priority date: 2008-06-27
Filing date: 2008-06-27
Publication date: 2009-12-30

Abstract

The present invention relates to an absorbent article (10) comprising: a chassis (12) extending about a longitudinal axis (L), a pair of opposed rear elastic side panels (26) attached to said chassis at a rear waist region (22), a fastening system comprising a first fastening member (30) with first fastening means (31) arranged on each rear elastic side panel and complementary second fastening means (32), whereby a waist elastic (24) is arranged to extend substantially parallel to a rear transverse edge (12c) and spaced therefrom by a second distance (B) and spaced from an absorbent structure (14) by a third distance (C), said waist elastic (24) terminating short of the longitudinal edges (12a,b) by a fourth distance (D), wherein said rear elastic side panels (26) and said waist elastic (24) are tailored such that, when said rear waist region (22) is in a substantially maximum extended state, the relative extension of the side panels (26) is approximately the same as or greater than the relative extension of the waist elastic (24), and wherein said first fastening means (31) of the rear side panels (26) are positioned on a second transverse axis (X) extending substantially parallel to said first transverse axis (T), with said second transverse axis (X) passing through said waist elastic (24), such that, during extension of said rear waist region (22) from its relaxed state to a substantially maximum extended state, said waist elastic (24) will reach a substantial proportion of its maximum relative extension before said rear elastic side panels (26) reach the same substantial proportion of their maximum relative extension from their relaxed state.

Description

ABSORBENT ARTICLE WITH IMPROVED FIT AND IMPROVED CAPABILITY TO STAY IN PLACE DURING USE

TECHNICAL FIELD The present invention relates to an absorbent article, such as a disposable diaper or an incontinence guard, for an adult or a child, which absorbent article has improved fit and improved capability to stay in place during normal use.

BACKGROUND OF THE INVENTION Disposable diapers conventionally include a chassis having a liquid permeable topsheet, a liquid impermeable backsheet and an absorbent structure sandwiched between the topsheet and backsheet. The chassis has a front body panel which, in use, extends over the stomach and front hip area of the user, and a rear body panel which, in use, extends over the back and rear hip area of the user. Each of the body panels has a waist portion such that, when the diaper is fastened around the waist of the user, the waist portions provide a continuous encirclement of the user. In order to fasten the diaper around the waist of a user, a fastening system comprising fastening tabs is commonly employed. Fastening tabs may be provided on side panels which extend from lateral side edges of the diaper chassis.

As a user of a diaper moves about (i.e. eats, breathes, sneezes, crawls, walks, jumps, etc.), the circumference of the user's waist expands and contracts, which consequently results in the waist portions of the diaper being strained and relaxed. Repeated or exaggerated expansion and contraction of the waist portions may lead to permanent deformation of the waist portions, resulting in a slackening of the diaper around the waist. Particularly for active toddlers wearing diapers which already contain an insult, this often results in the diaper slipping down, thereby increasing the risk for leakage.

To reduce the risk of leakage when worn, a diaper should be provided with form-fitting properties at least in some areas. The form-fitting properties also contribute to an improved appearance of the diaper when worn by the user. Typically, one or both waist portions may contain an elastic waistband. Furthermore, the side panels on which the fastening tabs are provided may display elastic properties. However, even though many conventional diapers exhibit some form-fitting properties, the resistance to leakage is nevertheless decreased if the diaper is not correctly fastened around the waist of a user.

On the market today there are absorbent articles, which have form-fitting properties and which comprise elastic regions being arranged so as to reduce the risk of incorrect fastening of the absorbent articles around the waist of the user and so as to contribute to a good fit and capability to stay in place during normal use. However, there is still room for improvement of such absorbent articles such that the fit and capability to stay in place during normal use are improved.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide an improved absorbent article, such as a disposable diaper or an incontinence guard, whereby the absorbent article is improved in that it has an improved fit and an improved capability to stay in place during normal use.

This object is achieved by an absorbent article which comprises: a chassis extending about a longitudinal axis (L), said chassis including a liquid permeable topsheet, a liquid impermeable backsheet and an absorbent structure disposed between said topsheet and said backsheet, said chassis having a first transverse axis (T) dividing the absorbent article into a front body panel terminating in a front waist region and a rear body panel terminating in a rear waist region, said chassis being delimited by opposed longitudinal edges and opposed rear and front transverse edges; a pair of opposed rear elastic side panels attached to said chassis at said rear waist region of said rear body panel, each rear elastic side panel extending outwardly from the respective longitudinal edge of the chassis, and a fastening system for fastening the absorbent article around the waist of a user, the fastening system comprising a first fastening member with first fastening means arranged on each opposed rear elastic side panel and complementary second fastening means arranged on said front body panel, whereby in said rear waist region, said absorbent structure terminates at a first distance from said rear transverse edge and a waist elastic is arranged to extend substantially parallel to said rear transverse edge and spaced therefrom by a second distance and spaced from said absorbent structure by a third distance, said waist elastic terminating short of the longitudinal edges by a fourth distance.

The absorbent article includes the features - that said rear elastic side panels and said waist elastic are tailored such that, when said rear waist region is in a substantially maximum extended state, the relative extension of the rear elastic side panels is approximately the same as or greater than the relative extension of the waist elastic, and

- that said first fastening means of the rear elastic side panels are positioned on a second transverse axis extending substantially parallel to said first transverse axis, with said second transverse axis (X) passing through said waist elastic, such that, during extension of said rear waist region from its relaxed state to a substantially maximum extended state, said waist elastic will reach a substantial proportion of its maximum relative extension before said rear elastic side panels reach the same substantial proportion of their maximum relative extension from their relaxed state.

With "relative extension" is meant the proportion that a side panel or the waist elastic is extended when submitted to an extending force (i.e. the length of the side panel or waist elastic when extended divided with the initial, relaxed length of the side panel or waist elastic.) The relevant force for achieving a substantially maximum extended state of an article such as diaper or incontinence article is readily obtainable by stretching the product between the first fastening means such as before attaching it to a user. The relevant forces are generally deemed to be about 7 N.

That the relative extension of the rear side panels is approximately the same as or greater than the relative extension of the waist elastic means that, if the rear waist region is extended to its maximum extended state, both the waist elastic and the rear elastic side panels will extend significantly in relation to their initial, relaxed length. Hence, it is understood that the side panels and the waist elastic will both contribute to the capability of the article to adapt to the user when the article is worn. This is in contrast to prior art products where the elasticity of the side panels and the waist elastic differ largely, such that the most elastic of the two will take up virtually all of the necessary extension of the article when worn. Moreover, it is believed that the locations of the rear elastic side panels and the waist elastic contribute to a force distribution which results in that, when the first fastening means located on the rear elastic side panels are pulled apart, said waist elastic will reach a substantial proportion of its maximum relative extension before said rear elastic side panels reach the same substantial proportion of their maximum relative extension from their relaxed state. This generally means that the waist elastic will extend before the rear elastic side panels extend when the article is stretched by pulling apart the first fastening means.

In the case where there are several, or a longitudinally extending, first fastening means on the rear elastic side panels, it is understood that the second transverse axis (X) should be drawn through a longitudinal middle position thereof.

The waist elastic extending first when the first fastening means are pulled apart, as when the diaper is stretched by a caretaker before being attached to a user, means that the waist elastic of the article will generally always be in a stretched state when the article is worn. Accordingly, the waist elastic lies close to the back of a wearer in use. This is significant as the waist elastic per se may hinder leakage of e.g. feces or urine towards the back of the user. This sealing effect of the waist elastic is particularly useful when combined with barriers such as standing gathers, which may extend along the absorbent core of the article and up to the waist elastic, such that the waist elastic and the standing gathers together may form a seal against leakage.

In view of the above it is understood that the article according to the invention combines the advantages of increased adaptation to the wearer's movements as may be obtained by increasing the relative extension of the rear elastic side panels, while ensuring that the waist elastic is stretched when the article is worn.

It is believed that the improved fit obtained by the article according to the invention is caused by the positioning of the waist elastic in the article in combination with the positions of the rear elastic side panels, which cooperates with the relative extension of the rear elastic side panels being approximately the same as or greater than the relative extension of the waist elastic. Advantageously, a "substantial proportion of the maximum relative extension" could be determined to be more than 50% of the maximum relative extension, more preferred more than 70% of the maximum relative extension.

Preferably, the rear elastic side panels and the waist region are tailored such that the contribution of the elongation of the two rear elastic side panels to the total elongation of the two rear elastic side panels and the waist elastic, when the rear waist region is in its maximum extended state, is substantially equal to or greater than the contribution of the elongation of the waist elastic to the total elongation of the two rear elastic side panels and the waist elastic.

Hence, both the rear elastic side panels and the waist elastic will contribute significantly to the total extension of the rear waist region when in its maximum extended state. This is believed to be particularly advantageous for the capacity of the product to adapt to the movements of the user when the article is worn.

Moreover, the above-referenced object is achieved by an absorbent article, such as a disposable diaper or an incontinence guard, which comprises: a chassis extending about a longitudinal axis (L), said chassis including a liquid permeable topsheet, a liquid impermeable backsheet and an absorbent structure disposed between said topsheet and said backsheet, said chassis having a first transverse axis (T) dividing the absorbent article into a front body panel terminating in a front waist region and a rear body panel terminating in a rear waist region, said chassis being delimited by opposed longitudinal edges and opposed rear and front transverse edges; a pair of opposed rear elastic side panels attached to said chassis at said rear waist region of said rear body panel, each rear elastic side panel extending outwardly from the respective longitudinal edge of the chassis, and a fastening system for fastening the absorbent article around the waist of a user, the fastening system comprising a first fastening member with first fastening means arranged on each opposed rear elastic side panel and complementary second fastening means arranged on said front body panel, whereby in said rear waist region, said absorbent structure terminates at a first distance from said rear transverse edge and a waist elastic is arranged to extend substantially parallel to said rear transverse edge and spaced therefrom by a second distance and spaced from said absorbent structure by a third distance, said waist elastic terminating short of the longitudinal edges by a fourth distance, said waist elastic is tailored such that when tested on a tensile testing apparatus and using a force of 7N according to the Cyclic Load and Unload Test of Waist Elastic as described herein, a first quotient (Q_{I W}E) is 1.3-1 .8, wherein the first quotient (Q_{I W}E) is obtained by dividing a gauge length (L_1st7N) at 1 ^st load 7N with an initial gauge length (L₀).

In particular, the first fastening means of the rear elastic side panels are positioned on a second transverse axis extending substantially parallel to said first transverse axis, with said second transverse axis passing through said waist elastic, and that each rear elastic side panel is tailored such that when tested on a tensile testing apparatus and using a force of 7N according to the Cyclic Load and Unload Test of Elastic Side Panel as described herein, a first quotient (Q_I E_SP) is 1 .3-1 .8, preferably 1 .4-1 .6, wherein the first quotient (Q_I E_SP) is obtained by dividing a gauge length (L_1st7N) at 1^st load 7N with an initial gauge length (L₀).

The first quotient of the waist elastic is approximately in the same range as the first quotient of the rear elastic side panels, meaning that, if the rear waist region is extended to its maximum extent, both the waist elastic and the rear elastic side panels will significantly contribute to the total elasticity of the rear waist region of the diaper. This is in contrast to prior art products where the elasticity of the side panels and the waist elastic differ largely, such that the most elastic of the two will take up virtually all of the necessary extension of the article when worn. It should be noted, that although the first quotient of the waist elastic is approximately in the same range as the first quotient of the rear elastic side panels, it is not necessary that the two are equal. Advantageously, the first quotient of the side panels could be greater than the first quotient of the waist elastic. Hence the first quotient reflects the term "relative extension" as used above.

Moreover, the first quotient of the rear elastic side panels is preferably in the range 1 .3- 1 .8, more preferred 1 .4-1 .6. It has been found that this enables a particularly good fit of the product. Hence, it is believed that this range is particularly suitable to find the balance between sufficient elasticity to enable unhindered movement of the user, and sufficient resistance against leakage. Advantageously, said second transverse axis (X) passes through a lower half of a longitudinal extension of said waist elastic. Preferably, the second transverse axis passes through the lower 50%, most preferred through the lower 25%, of the longitudinal extension of said waist elastic. Advantageously, the axis passes above the lowest 5% of the longitudinal extension of the waist elastic. This provides a particularly advantageous force distribution when pulling the first fastening means apart so as to achieve the intended effects.

Advantageously, the rear elastic side panels and said waist elastic are tailored such that when said rear waist region is extended from its relaxed state using a tensile testing apparatus and a force of 7N according to the Interaction Test Il described herein, said waist elastic will reach a substantial proportion of its maximum relative extension before said rear elastic side panels reach the same substantial proportion of their maximum relative extension from their relaxed state. The force of 7 N corresponds approximately to the force used when opening an article for attachment to a user.

Moreover, the object is achieved by an article wherein, the rear elastic side panels and said waist elastic are tailored such that when said rear waist region is tested on a tensile testing apparatus and using a force of 7N according to the Interaction Test I as described herein, a second quotient is 0.80-1 .70, preferably 0.90-1.60, and most preferably 1 .35- 1 .60, said second quotient being obtained by dividing: an elastic side panel proportion (%2ESP) being the percent contribution of the elongation of the two rear elastic side panels to the total elongation of the two rear elastic side panels and the waist elastic, with a waist elastic proportion (%WE) being the percent contribution of the elongation of the waist elastic to the total elongation of the two rear elastic side panels and the waist elastic. This is a way of expressing the proportion of the total elongation of the waist region taken up by the waist elastic and by the rear side panels, respectively. As is understood by the above ranges, both the waist elastic and the rear side panels add a significant contribution to the total elongation.

In such an article, improved adaptation to the movements of a user is achieved by the contribution of the rear elastic side panels to the total elongation of the waist area, being about as great or greater than the contribution of the waist elastic to the total elongation of the waist area. However, the article is still capable of fulfilling the above-referenced desire that said waist elastic will reach a substantial proportion of its maximum relative extension before said rear elastic side panels reach the same substantial proportion of their maximum relative extension from their relaxed state, when said rear waist region is extended.

Advantageously, said waist elastic is terminating in a transverse direction short of a first longitudinal edge by a fourth distance, preferably being in the range 30-70 mm, most preferred in the range 40-60 mm.

Advantageously, the second transverse axis X is located at a fifth distance from the rear transverse edge, said fifth distance preferably being in the range 23-35 mm.

Advantageously, each rear elastic side panel terminates at a sixth distance from the rear transverse edge, said sixth distance preferably being in the range 0-10 mm, most preferred 0-2 mm.

Preferably, said waist elastic has a length of 85-1 15 mm, preferably 90-1 10 mm, in the transverse direction of the absorbent article in a relaxed state and/or a length of 10-50 mm, preferably 20-40 mm, in the longitudinal direction of the absorbent article in a relaxed state.

Advantageously, the rear elastic side panels each have a length of 40-65 mm, preferably 45-60 mm, outside the chassis in the transverse direction of the absorbent article in a relaxed state.

Preferably, each rear elastic side panel is tailored such that when tested on a tensile testing apparatus and a force of 7N according to the Cyclic Load and Unload Test of Elastic Side Panel as described herein, a third quotient (Q₃) is 1 .35-1 .70, preferably 1 .37- 1 .65, and most preferably 1 .40-1 .60, said third quotient (Q₃) being obtained by dividing a gauge length (L_3rd7N) at 3^rd unload 7N with an initial gauge length (L₀). This indicates that the elastic properties of the side panels are maintained during a wearing period of the article.

Advantageously, each rear elastic side panel is tailored such that when tested according to the Permanent Deformation Test as described herein, the permanent deformation (DRERM) is < 6.0%, preferably < 5.5% and most preferably < 5.0%. Preferably, said rear elastic side panels and said waist elastic are tailored such that when tested on a Cyclic Waist Expansion Test apparatus according to the Cyclic Waist Expansion Test as described herein, the absorbent article does not slip down more than 10 mm from its initial position on the Cyclic Waist Expansion Test apparatus during at least 15 expansion/contraction cycles of the Cyclic Waist Expansion Test and within 5-10 seconds after being subjected to at least 15 expansion/contraction cycles of the Cyclic Waist Expansion Test.

Preferably, each rear elastic side panel has at least one elastic region and at least two inelastic regions.

Most preferred, each rear elastic side panel is attached to said chassis at one of said inelastic regions.

Moreover, the object is achieved by an article, wherein each elastic side panel is made of an elastic nonwoven laminate produced by an extrusion based thermic bonding of an extruded elastic film layer and two nonwoven layers, whereby said elastic film layer is sandwiched between said nonwoven layers, whereby said elastic film layer is covered by one of said nonwoven layers on one side and by the other of said nonwoven layers on an opposite side such that said sides of said elastic film layer are completely covered by said respective nonwoven layers, whereby said elastic nonwoven laminate comprises elastic and inelastic zones, whereby each elastic region of said elastic side panel is constituted by an elastic zone of said laminate and each inelastic region of said elastic side panel is constituted by an inelastic zone of said laminate.

Such a material has been found to be capable of being successfully tailored to the needs of an article as set out above.

Advantageously, said waist elastic is constituted by an elastic film.

It is understood that the above-referenced features may form various combinations, which per se are useful for obtaining various advantageous articles.

In particular, the above-mentioned object is achieved by an absorbent article comprising: a chassis extending about a longitudinal axis (L), said chassis including a liquid permeable topsheet, a liquid impermeable backsheet and an absorbent structure disposed between said topsheet and said backsheet, said chassis having a first transverse axis dividing the absorbent article into a front body panel terminating in a front waist region and a rear body panel terminating in a rear waist region, said chassis being delimited by opposed longitudinal edges and opposed rear and front transverse edges; a pair of opposed rear elastic side panels attached to said chassis at said rear waist region of said rear body panel, each rear elastic side panel extending outwardly from the respective longitudinal edge of the chassis, and a fastening system for fastening the absorbent article around the waist of a user, the fastening system comprising a first fastening member with first fastening means arranged on each opposed rear elastic side panel and complementary second fastening means arranged on said front body panel, whereby in said rear waist region, said absorbent structure terminates at a first distance from said rear transverse edge and a waist elastic is arranged to extend substantially parallel to said rear transverse edge and spaced therefrom by a second distance and spaced from said absorbent structure by a third distance, said waist elastic terminating short of the first longitudinal edges by a fourth distance, wherein the rear elastic side panels and said waist elastic are tailored such that when said rear waist region is tested on a tensile testing apparatus and using a force of 7N according to the Interaction Test I as described herein, a second quotient is 0.80-1 .70, preferably 0.90- 1 .60, and most preferably 1 .35-1 .60, said second quotient being obtained by dividing: an elastic side panel proportion (%2ESP) being the percent contribution of the elongation of the two rear elastic side panels to the total elongation of the two rear elastic side panels and the waist elastic, with a waist elastic proportion (%WE) being the percent contribution of the elongation of the waist elastic to the total elongation of the two rear elastic side panels and the waist elastic.

Naturally, this article may be combined with one or several of the features as set out above. In particular, it may advantageously be combined with the feature that the first fastening means of the rear elastic side panels are positioned on a second transverse axis extending substantially parallel to said first transverse axis, with said second transverse axis passing through said waist elastic. Moreover, the above-mentioned object is achieved by an absorbent article comprising: a chassis extending about a longitudinal axis (L), said chassis including a liquid permeable topsheet, a liquid impermeable backsheet and an absorbent structure disposed between said topsheet and said backsheet, said chassis having a first transverse axis dividing the absorbent article into a front body panel terminating in a front waist region and a rear body panel terminating in a rear waist region, said chassis being delimited by opposed longitudinal edges and opposed rear and front transverse edges; a pair of opposed rear elastic side panels attached to said chassis at said rear waist region of said rear body panel, each rear elastic side panel extending outwardly from the respective longitudinal edge of the chassis, and a fastening system for fastening the absorbent article around the waist of a user, the fastening system comprising a first fastening member with first fastening means arranged on each opposed rear elastic side panel and complementary second fastening means arranged on said front body panel, whereby in said rear waist region, said absorbent structure terminates at a first distance from said rear transverse edge and a waist elastic is arranged to extend substantially parallel to said rear transverse edge and spaced therefrom by a second distance and spaced from said absorbent structure by a third distance, said waist elastic terminating short of the longitudinal edges by a fourth distance, wherein each rear elastic side panel has at least one elastic region and at least two inelastic regions, said first fastening means of the rear elastic side panels are positioned on a second transverse axis (X) extending substantially parallel to said first transverse axis (T), with said second transverse axis (X) passing through said waist elastic, and each rear elastic side panel is made of an elastic nonwoven laminate produced by an extrusion based thermic bonding of an extruded elastic film layer and two nonwoven layers, whereby said elastic film layer is sandwiched between said nonwoven layers, whereby said elastic film layer is covered by one of said nonwoven layers on one side and by the other of said nonwoven layers on an opposite side such that said sides of said elastic film layer are completely covered by said respective nonwoven layers, whereby said elastic nonwoven laminate comprises elastic and inelastic zones, whereby each elastic region of said rear elastic side panel is constituted by an elastic zone of said laminate and each inelastic region of said elastic side panel is constituted by a inelastic zone of said laminate.

Still other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures described herein.

Naturally, this article may be combined with one or several of the features as set out above.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, wherein like reference characters denote similar elements throughout the several views:

Figures 1 -2 show one embodiment of an absorbent article according to the invention; Figures 3a-3b schematically shows a rear elastic side panel according to one embodiment of the invention in an enlarged top view and a cross-sectional side view, respectively; Figure 4a shows a rear elastic side panel according to one embodiment of the invention prior to testing according to the Cyclic Load and Unload Test of

Elastic Side Panel; Figure 4b shows a test sample comprising waist elastic according to one embodiment of the invention prior to testing according to the Cyclic Load and Unload

Test of Waist Elastic; Figure 4c shows a rear waist region according to one embodiment of the invention prior to testing according to the Interaction Test I; Figure 5 shows a rear waist region according to an embodiment of the invention being tested on a tensile testing machine to determine a length, L_7N ; Figures 6-12 schematically show the Cyclic Waist Expansion Test Apparatus according to an embodiment of the invention,

Figure 13 shows the position in which a weight is placed in an absorbent article during the Cyclic Waist Expansion Test, and Figure 14 schematically shows the stripe light projection (SLP) apparatus used to measure the surface roughness of a front side panel of an absorbent article.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will now be described in further detail in the following with reference to the accompanying figures.

As mentioned previously, the invention concerns an absorbent article, such as a disposable diaper or an incontinence guard. Such articles are commonly used for acquisition and storage of bodily exudates such as urine, faeces or menstrual fluid. The absorbent article according to the invention is preferably disposable - i.e. it is intended to be used only once and disposed thereafter rather than being cleaned and re-used.

Figures 1 and 2 show one embodiment of an absorbent article 10 according to the invention, namely a disposable diaper that assumes a pant-like shape when fastened around the waist of a user. The absorbent article 10 comprises a chassis 12 extending about a longitudinal axis, L, said chassis 12 including a liquid permeable topsheet 13, a liquid impermeable backsheet 15 and an absorbent structure 14 disposed between the topsheet 13 and the backsheet 15. The chassis 12 has a first transverse axis, T, dividing the absorbent article 10 into a front body panel 16 terminating in a front waist region 18 and a rear body panel 20 terminating in a rear waist region 22.

The topsheet 13 and the backsheet 15 extend outside the edges of the absorbent structure 14 and are connected (sealed) to each other within the projecting portions thereof, e.g. by gluing or welding or by heat or ultrasound. The topsheet 13 and/or the backsheet 15 may be further attached to the absorbent structure 14 by any known method in the art, such as by means of adhesive, heat bonding, etc. The absorbent structure 14 may also be attached to the topsheet 13 and/or the backsheet 15 in certain regions only.

The liquid permeable topsheet 13 may comprise apertures through which liquid can permeate, or alternatively, liquid may permeate through the spaces between individual fibres. It may be any material used for this purpose, for example a nonwoven material, such as a spunbond material of continuous filaments, a meltblown material, a thermobonded fibrous web such as a carded fibrous web, a hydroentangled material, a wetlaid material, etc. The topsheet 13 may comprise many different types of fibres. For example, natural fibres such as wood pulp or cotton fibres, jute, wool and hair fibres may be used. Man-made fibres, such as e.g. polyester, viscose, nylon, polypropylene, and polyethylene may also be used, polypropylene and polyester being preferred. Mixtures of different fibres types may also be used, e.g. a 50/50 mix of polyester and viscose. Bicomponent fibres or binder fibres may also be used. The topsheet may also be a layer of so called tow fibres bonded in a bonding pattern, as e.g. disclosed in EP-A-1 035 818, or a perforated plastic film. The materials suited as top sheet materials should be soft and non-irritating to the skin and intended to be readily penetrated by body liquid, e.g. urine or menstrual liquid. The topsheet material may be different in different parts of the absorbent article.

The topsheet 13 may be treated with a chemical agent to improve one or more of its properties. For example, treatment of the topsheet 13 with surfactants will make it more liquid-permeable. Treatment of the topsheet 13 with a lotion, e.g. as described in EP1227776 provides a softer, more comfortable feel to the wearer, and improved skin properties.

Furthermore, the topsheet 13 may comprise at least two separate but interconnected layers. Each layer may comprise the same materials or may comprise different materials with different properties as regards e.g. strength, stiffness, liquid or gas permeability. Each layer may also be a laminate of two or more sub-layers.

The liquid impermeable backsheet 15 may consist of any suitable material. For example, the backsheet 15 may consist of a thin plastic film, such as a polyethylene or polypropylene film, a nonwoven material coated with a liquid impervious material, a hydrophobic nonwoven material which resists liquid penetration, or a laminate of plastic films and nonwoven materials. The backsheet 15 may be breathable so as to allow vapour to escape from the absorbent structure 14, while still preventing liquids from passing through the backsheet material. The backsheet 15 may be elastic. The material of the backsheet 15 may be different in different regions of the backsheet 15.

The absorbent structure 14 may be of any conventional kind. Examples of commonly occurring absorbent materials are cellulosic fluff pulp, tissue layers, highly absorbent polymers (so called super-absorbents), absorbent foam materials, absorbent non-woven materials or the like. It is common to combine cellulosic fluff pulp with super-absorbent polymers in an absorbent structure. Super-absorbent polymers are water-swellable, water-insoluble organic or inorganic materials capable of absorbing at least about 10 times their own weight of an aqueous solution containing 0.9 weight percent of sodium chloride. Organic materials suitable for use as super-absorbent materials 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 super- absorbent materials are further surface cross-linked so that the outer surface or shell of the super-absorbent particle, fibre, flake, sphere, etc. possesses a higher crosslink density than the inner portion of the super-absorbent.

A high liquid storage capacity is provided by the use of large amounts of super-absorbent material. For an absorbent structure comprising a matrix of hydrophilic fibres, such as cellulosic fibres, and super-absorbent material, the proportion of super-absorbent material is preferably between 10 and 90% by weight, more preferably between 30 and 70% by weight.

It is conventional for absorbent articles to have absorbent structures comprising layers of different properties with respect to liquid receiving capacity, liquid distribution capacity and storage capacity. The thin absorbent structures, which are common in, for example, disposable diapers and incontinence guards, often comprise a compressed, mixed or layered structure of cellulosic fluff pulp and super-absorbent polymers. The size and absorbent capacity of the absorbent structure may be varied to suit different uses, such as infants or adult incontinent persons.

The absorbent structure may further include an acquisition distribution layer placed on top of the primary absorbent body, which is adapted to quickly receive and temporarily store discharged liquid before it is absorbed by the primary absorbent structure. Such acquisition distribution layers are well known in the art and may be composed of porous fibrous wadding or foam materials. The absorbent structure 14 may have a uniform thickness over its extension. However, it may alternatively have a varying thickness over its extension. For example, the absorbent structure in the rear body panel 20 may be thinner than the absorbent structure in the front body panel 16, namely up to 50% thinner, preferably up to 25% thinner. The absorbent structure 14 illustrated in figure 2 has a rounded end in the vicinity of the rear waist region 22 and is arranged to have a gradually decreasing thickness in the longitudinal direction L of the absorbent article starting from the point at which the longitudinal axis L cross the first transverse axis T in figure 2 outwardly to the rounded end. The decreased thickness of the rounded end of the absorbent structure 14 allows the rounded end to gather around the waist of the user's body and thus provide an improved fit when the absorbent article 10 is in use and it also makes the absorbent article 10 lighter. Thus, the absorbent structure 10 may be thinnest in the vicinity of the rear waist region 22 and may have a thickness of 3-5 mm in the vicinity of the rear waist region 22 (measured to an accuracy of ± 0.03 mm using a thickness gauge with a foot having an area of 50 cm² and using a load pressure of 0.5 kPa).

The rear waist region 22 has waist elastic (i.e. a waist elastic region or an elastic waist band) 24, which preferably is located between the topsheet 13 and the backsheet 15 of the chassis 12. If the waist elastic 24 were to be placed outside the topsheet 13 so that it were located adjacent to the skin of a user when the absorbent article 10 were in use, it could create more friction against the skin of the user and thus make the absorbent article 10 less comfortable to wear.

For example, the waist elastic 24 may be constituted by an elastic film. The elastic film may be of any suitable elastic polymer, natural or synthetic. Some examples of suitable materials for the elastic film are low crystallinity polyethylenes, metallocene-catalyzed low crystallinity polyethylene, ethylene vinyl acetate copolymers (EVA), polyurethane, polyisoprene, butadiene-styrene copolymers, styrene block copolymers, such as styrene/isoprene/styrene (SIS), styrene/butadiene/styrene (SBS), or styrene/ethylene- butadiene/styrene block copolymer. Blends of these polymers may also be used as well as other modifying elastomeric or non-elastomeric materials.

The waist elastic 24 may be contractably attached between the topsheet 13 and backsheet 15 or it may be contractably attached to the inside surface of the topsheet 13 or the inside surface of the backsheet 15, whereby the "inside surface" is the surface facing the absorbent structure 14.

For example, the waist elastic 24 may have a length of 25-55% of the width of the rear 5 body panel 20 in the rear waist region 22 in the transverse direction of the absorbent article 10, particularly a length of 30-45% of the width of the rear body panel 20 in the transverse direction of the absorbent article 10, as measured in the initial non-elongated state of the waist elastic 24.

10 The waist elastic 24 may have a length of, for example, 10-50 mm in the longitudinal direction of the absorbent article 10, preferably 20-40 mm in the longitudinal direction of the absorbent article 10.

Furthermore, the chassis 12 is delimited by opposed longitudinal edges 12a and 12b and 15 opposed rear and front transverse edges 12c and 12d. A pair of opposed rear elastic side panels 26 is attached to the chassis 12 at the rear waist region 22 of the rear body panel 20. Each rear elastic side panel 26 extends outwardly from the respective longitudinal edge 12a, 12b of the chassis 12.

20 In the illustrated embodiment, each rear elastic side panel 26 has one elastic region 27 and two inelastic regions 28. However, each rear elastic side panel 26 may alternatively comprise more than one elastic region 27 and/or more than two inelastic regions 28 (not shown). Furthermore, in the illustrated embodiment, each rear elastic side panel 26 comprises the inelastic regions 28 at end areas, whereby each rear elastic side panel 26

25 is attached to the chassis 12 at one of the inelastic regions 28. Thus, an inelastic region 28 is utilized for the attachment of each rear elastic side panel 26 to the chassis 12. The other inelastic region 28 is utilized for the attachment of the first fastening member 30. The arrangement of the inelastic regions 28 at end areas of the rear elastic side panels 26 facilitate the attachment of the rear elastic side panels 26 to the chassis 12 and the first

30 fastening member 30, respectively. The rear elastic side panels 26 will be further described below. A separate rear elastic side panel 26 detached from the absorbent article 10 shown in figures 1 and 2 is shown in a top view in figure 3a.

For example, the elastic region(s) 27 may constitute 25-55% of the rear elastic side panel 35 26. The rear elastic side panels 26 and the waist elastic 24 are arranged to be capable of being elongated in a substantially transverse direction of the absorbent article 10, whereby the expressions "elastic" and "inelastic" as used in this document are defined using the elasticity test described below.

The absorbent article 10 also comprises a fastening system for fastening the absorbent article 10 around the waist of a user. The fastening system comprises a first fastening member 30 arranged on each rear elastic side panel 26. In the illustrated embodiment, each first fastening member 30 comprises one first fastening means 31. However, each first fastening member 30 could alternatively comprise more than one first fastening means 31. In addition, the fastening system comprises complementary second fastening means 32 arranged on the front body panel 16. In the illustrated embodiment, the first fastening member 30 is a tab, but may, however, be any other suitable means. The first fastening means 31 may be comprised in one or more regions of the first fastening member 30 and is the part or parts of the first fastening member 30 interacting with the complementary second fastening means 32. The first fastening means 31 may have any suitable shape and may have any suitable extension on the first fastening member 30. In the illustrated embodiment the complementary second fastening means 32 is shown as being comprised in one region only. However, the complementary second fastening means 32 may likewise be comprised in more than one region on the front body panel 16, i.e. the complementary second fastening means 32 may be arranged in two or more regions on the front body panel 16.

For example, the fastening system may be a mechanical fastening system. Examples of mechanical fastening systems are hook-and-loop fastening systems, systems comprising button and holes or button loops, systems comprising snap fasteners and the like.

A "hook-and-loop fastening system" refers to a fastening system having one or more "hook" portions (first fastening means) and one or more "loop" portions (complementary secondary fastening means), which are re-fastenable. The term "hook" as used herein refers to any element capable of engaging another element, the so called "loop" portion.

The term "hook" is not limited to only "hooks" in its normal sense, but rather encompasses any form of engaging elements, whether uni-directional or bi-directional. The term "loop" is likewise not limited to "loops" in its normal sense, but also encompasses any structure capable of engaging with a "hook" fastener. Examples of "loop" materials are fibrous structures, like non-woven materials. Hook-and-loop fasteners are for example available from Velcro, USA.

Furthermore, the external surface of the front body panel 16 may, for example, constitute or comprise a reception surface for the first fastening means 31 , i.e. the backsheet 15 of the front body panel 16 may be arranged to function as a reception surface for the first fastening means 31 , or a panel of material that is arranged to function as a reception surface for the first fastening means 31 may be attached to the external surface of the front body panel 16. Then the reception surface constitutes the complementary second fastening means 32. In cases where the first fastening means 31 is a hook fastener, a non-woven material may be used as the complementary second fastening means 32. Alternatively, the first fastening means 31 may be an adhesive fastening means such as an adhesive tape tab wherein at least part of the external surface of a front body panel 16 may be of a material to which the tape can adhere (complementary secondary fastening means), such as, for example, a plastic film or a non-woven material.

In the rear waist region 22, the absorbent structure 14 terminates at a first distance A from the rear transverse edge 12c. The waist elastic 24 extends substantially parallel to the rear transverse edge 12c and is spaced therefrom by a second distance B and spaced from the absorbent structure 14 by a third distance C. The waist elastic 24 terminates short of the longitudinal edges 12a, 12b by a fourth distance D, i.e. the waist elastic 24 is centred between the opposed longitudinal edges 12a and 12b of the chassis 12.

Furthermore, in accordance with the invention, the rear elastic side panels 26 and the waist elastic 24 are tailored such that, when said rear waist region 22 is in a substantially maximum extended state, the relative extension of the rear elastic side panels 26 is approximately the same as or greater than the relative extension of the waist elastic 24. In addition, the first fastening means 31 are positioned on a second transverse axis X extending substantially parallel to the first transverse axis T, with the second transverse axis X passing through the waist elastic 24 such that, during extension of the rear waist region 24 from its relaxed state to a substantially maximum extended state, said waist elastic 24 will reach a substantial proportion of its maximum relative extension before said rear elastic side panels 26 reach the same substantial proportion of their maximum relative extension from their relaxed state. In accordance with the above, the second transverse axis X passes from the first fastening means 31 on one of the first fastening members 30 to the first fastening means 31 on the other first fastening member 30. As shown in figures 1 and 2, the second transverse axis X may pass through, for example, a lower half of a longitudinal extension of the waist elastic 24. The second transverse axis X is located at a fifth distance E from the transverse edge 12c and each rear elastic side panel 26 terminates at a sixth distance F from the rear transverse edge 12c.

In the illustrated embodiment, the first distance A is measured in the longitudinal direction of the absorbent article 10 between an upper edge 14a of the absorbent structure 14 and the rear transverse edge 12c. The second distance B is measured in the longitudinal direction of the absorbent article 10 between an upper edge 24a of the waist elastic 24 and the rear transverse edge 12c, whereas the third distance C is measured in the longitudinal direction of the absorbent article 10 between a lower edge 24b of the waist elastic 24 and the upper edge 14a of the absorbent structure 14. The fourth distance D is measured in the transverse direction of the absorbent article 10 between a longitudinal edge 24c,d of the waist elastic 24 and the respective corresponding longitudinal edge 12a,b. The fifth distance E is measured in the longitudinal direction of the absorbent article 10 between the second transverse axis X and the rear transverse edge 12c. The sixth distance F is measured between an upper edge 26a of the rear elastic side panel 26 and the rear transverse edge 12c.

For example, the distance A may be between 35-80 mm, preferably between 40-60 mm. The second distance B may be, for example, between 10-30 mm. The third distance C may be, for example, between 0-50 mm, preferably between 10-35 mm. The fourth distance D may be, for example, between 30-70 mm, preferably between 40-60 mm. The fifth distance E may be, for example, between 23-35 mm. The sixth distance F may be, for example, between 0-10 mm, preferably 0-2 mm.

Advantageously, the third distance C may be less than the second distance B.

The above described arrangement of the waist elastic 24, the rear elastic side panels 26 and the first fastening means 31 in relation to each other and in relation to other components of the absorbent article 10 implies that a synergistic effect occurs between the waist elastic 24 and the rear elastic side panels 26 when the absorbent article 10 is in use. The synergistic effect makes the absorbent article 10 not only comfortable to wear and easy to fasten and handle, but also provides a good fit and ensures that the absorbent article 10 stays reliably in place during use even if its user is very active.

The synergistic effect is particularly promoted due to the fact the first fastening means 31 are positioned on a second transverse axis X, which passes through the waist elastic 24. The location of the second transverse axis X promotes the cooperation of the rear elastic side panels 26 and the waist elastic 24.

Furthermore, according to the invention, the fit and capability to stay in place during normal use of the absorbent article 10 are further improved by the fact that each rear elastic side panel 26 is tailored such that when tested on a tensile testing apparatus and using a force of 7N according to the Cyclic Load and Unload Test of Elastic Side Panel as described herein in the Experimental section, a first quotient, Q_I E_SP, is 1 .3-1 .8, preferably 1 .4-1 .6, said first quotient, Q_I E_SP, being obtained by dividing a gauge length, L_1st7N, at 1^st load 7N with an initial gauge length, L₀. The gauge length is the length of a tested rear elastic side panel between the clamps of a tensile testing apparatus. Thus, the gauge length corresponds to (i.e. it is equal to) the distance between the clamps of the tensile testing apparatus, which is denoted as tensioning distance. This will be further described in the Experimental section.

The rear elastic side panels 26 and the waist elastic 24 of the illustrated embodiment are tailored such that when the rear waist region 22 is extended from its relaxed state using a tensile testing apparatus and a force of 7N according to the Interaction Test Il as described herein, the waist elastic 24 is extended to a substantial proportion of its maximum relative extension before the rear elastic side panels 26 is extended to the same substantial proportion of their maximum relative extension from their relaxed state.

Advantageously, the rear elastic side panels 26 and the waist elastic 24 are tailored such that when the rear waist region 22 is tested on a tensile testing apparatus and using a force of 7N according to the Interaction Test I as described herein, a second quotient, Q₂, is 0.80-1 .70, preferably 0.90-1 .60, and most preferably 1 .35-1 .60. The second quotient, Q₂, is obtained by dividing: - an elastic side panel proportion, %2ESP, being the percent contribution of the elongation of the two rear elastic side panels 26 to the total elongation of the two rear elastic side panels 26 and the waist elastic 24, with

- a waist elastic proportion, %WE, being the percent contribution of the elongation of the waist elastic 24 to the total elongation of the two rear elastic side panels 26 and the waist elastic 24.

Advantageously, each rear elastic side panel 26 is tailored such that when tested on a tensile testing apparatus and a force of 7N according to the Cyclic Load and Unload Test of Elastic Side Panel as described herein, a third quotient, Q₃, is 1.35-1 .70, preferably 1 .37-1 .65, and most preferably 1 .40-1 .60, said third quotient, Q₃, being obtained by dividing a gauge length, L_3rd7N, at 3^rd unload 7N with an initial gauge length, L₀.

Advantageously, each rear elastic side panel 26 is tailored such that when tested according to the Permanent Deformation Test as described herein, the permanent deformation, D_PERM, is < 6.0%, preferably < 5.5% and most preferably < 5.0%.

Advantageously, the rear elastic side panels 26 and the waist elastic 24 are tailored such that when tested on a Cyclic Waist Expansion Test apparatus 48 according to the Cyclic Waist Expansion Test as described herein, the absorbent article 10 does not slip down more than 10 mm from its initial position on the Cyclic Waist Expansion Test apparatus 48 during at least 15 expansion/contraction cycles of the Cyclic Waist Expansion Test and within 5-10 seconds after being subjected to at least 15 expansion/contraction cycles of the Cyclic Waist Expansion Test.

Advantageously, each of the rear elastic side panels 26 of the absorbent article 10 according to the invention is made of an elastic nonwoven laminate produced by extrusion based thermic bonding of an extruded elastic film layer 44 and two nonwoven layers 46. The elastic film layer 44 is sandwiched between the two nonwoven layers 46. The elastic film layer 44 is covered by one of said nonwoven layers 46 on one side and by the other of said nonwoven layers 46 on an opposite side such that said sides of the elastic film layer 44 are completely covered by the respective nonwoven layers 46. Figures 3a and 3b shows schematically a rear elastic side panel 26 being detached from the absorbent article 10 in figures 1 and 2 and being made of such an elastic nonwoven laminate in an enlarged top view and a cross-sectional side view, respectively. The cross-sectional view shown in figure 3b is taken along line llla-llla in figure 3a.

Furthermore, the elastic nonwoven laminate comprises elastic and inelastic zones (i.e. active and non-active zones, respectively), whereby the elastic region 27 of each elastic side panel 26 is constituted by an elastic zone of the laminate and each inelastic region 28 of each elastic side panel 26 is constituted by a inelastic zone of the laminate.

For example, the nonwoven layers 46 of the elastic nonwoven laminate may be made of a nonwoven material of carded polypropylene, which nonwoven material has a basis weight of 24 g/m². The elastic film 44 of the elastic nonwoven laminate may be made of styrene- ethylene/butylene-styrene and may have a basis weight of 70 g/m².

The elastic laminate may be, for example, koester FlexEar PA, 1 14 gsm (koester GmbH & Co. KG, Altendorf, Germany) or Elastipro 7001 (Clopay Plastics Products Co., Mason, OH, USA).

In the illustrated embodiment, each of the opposed longitudinal edges 12a, 12b comprises a leg contour 34, i.e. a curved outline that is arranged to fit around the leg of a user. Furthermore, the illustrated embodiment comprises leg elastic 36 that is arranged to extend in a curved line that is substantially parallel to the leg contour 34 when the chassis 12 is fully extended. The leg elastic 36 may comprise a plurality of elastic members, such as elastic threads that are contractably affixed between the topsheet 13 and the backsheet 15 of the absorbent article 10. The absorbent article 10 may also be provided with so called barrier cuffs, in order to provide an improved security against leakage. These barrier cuffs may in some instances replace leg elastics. However, the leg contour 34 and/or the leg elastic 36 may be omitted in the absorbent article 10 according to the invention.

In the illustrated embodiment, the chassis 12 comprises at least one absorbent-structure- free channel 38 that extends substantially in the longitudinal direction of the absorbent article 10 to facilitate the absorbent article 10 assuming a bowl-like shape when in use. However, the absorbent article 10 according to the invention need not comprise the channels 38. In the illustrated embodiment, the absorbent article 10 comprises a pair of opposed front side panels 40, comprising a nonwoven material for example, attached to the front body panel 16. However, the absorbent article 10 according to the invention need not comprise the front side panels 40. The front side panels 40 have a surface roughness where the vertical distance between a surface containing 5% of the material constituting a front side panel 40 and a surface containing 95% of the material constituting a front side panel 40 (an SDC 5-95% value) is 46 to 48 μm as measured using a stripe light projection (SLP) method (as described below and schematically illustrated in figure 14) and using MikroCAD optical 3D measuring device from GFMesstechnik from Gόttingen, wherein the front side panel material sample is placed on a planar surface and covered with plate glass through which measurements are made at a surface developed ratio or surface magnification of 125-128%.

In the SLP method a stripe of light from a triangulation laser is swept across a sample of material. A camera is used to determine the distance of a point along the stripe from the camera, which varies depending on how far away the laser stripe strikes a surface of the sample. The point on the laser stripe, the camera and the laser emitter form a triangle.

The length of one side of the triangle, the distance between the camera and the laser emitter is known. The angle of the laser emitter corner is also known. The angle of the camera corner can be determined by looking at the location of the laser dot in the camera's field of view. These three pieces of information fully determine the shape and size of the triangle and provide the location of the laser dot corner of the triangle.

The optica! 3D measunng device MiksoCAD is designed fos the thsee-dimeπsional inspection of the surface piofiie and ioughness of small samples and opesates with a high measuring vetocily and high precision The contescHess measurement method implements digital fi inge piojectioπ based on rrticio miπcus The 3D profile of the sample may be acqim ed within a few seconds

In the illustrated embodiment, the absorbent article 10 comprises material, such as topsheet material and breathable backsheet material, which constitutes at least one breathable zone 42 located in between a longitudinal edge of the chassis 12 and a longitudinally extending edge of the waist elastic 24, i.e. an edge that extends in the longitudinal direction of the absorbent article 10. The expression "breathable" means that said zone or material will allow water vapour to pass through it. The at least one breathable zone 42 may for example comprise a soft non-woven having a fine denier or a microporous or monolithic plastic film, which is intended to be in direct contact with the skin of a user of the absorbent article. A suitable non-woven material can be a spun- bonded material of polypropylene or polyethylene fibres. The at least one breathable zone 42 provides a chimney-like effect, which promotes air circulation within the absorbent article and consequently decreases the temperature inside the absorbent article during its use as compared to a non-breathable material. However, the absorbent article 10 according to the invention need not comprise the breathable zones 42.

The absorbent article 10 may be intended for a child or an adult. For example, the absorbent article 10 may be intended for a baby or an infant that weighs between 4 and 25 kg. It should be noted that an absorbent article 10 according to an embodiment of the invention is suitable for a child having a weight of 4-25 kg and that the absorbent article 10 is not arranged to fit all children in that weight range. Instead, the absorbent article may be formed in various sizes corresponding to different sub-ranges to fit differently sized children.

According to another embodiment of the invention the absorbent article 10 is arranged to be fastenable around the contoured plates of the Cyclic Waist Expansion Test apparatus, as described herein, in the manner described herein.

According to a further embodiment of the invention the absorbent article 10 comprises elastic regions in the rear waist region 22 only, i.e. the front waist region 18 comprises no waist elastic.

EXPERIMENTAL SECTION

In the various tests performed below, a number of products of each sample have been tested, such that average measures may be computed for each sample. However, it is understood that if it is necessary to determine any measure for one single sample, the test methods are applicable although it is not necessary to form a mean value. Cyclic Load and Unload Test of Elastic Side Panel

Aim:

The aim of the Cyclic Load and Unload Test of Elastic Side Panel is to determine the behavior of an elastic side panel during cyclic loading/unloading, i.e. repeated load and 5 unload cycles.

Test procedure:

Figure 4a schematically represents the Cyclic Load and Unload Test of Elastic Side Panel used to determine the behaviour of a rear elastic side panel 26 of an absorbent article 10

10 as illustrated in figures 1 and 2. The rear elastic side panel 26 of an absorbent article 10 was tested using a tensile testing machine (Lloyd LRX) using a force of 1 N, 2N, 3N, 4N, 5N, 6N and 7N (cell 5ON, test speed 300 mm/min, upper clamp 60mm, lower clamp 150mm, ruler accuracy ± 0.3mm). Seven Newtons is considered to be a suitable force when applying the product on a user. The tests were carried out in a climatised room at a

15 temperature of 23 ± 1 ⁰C, relative humidity of 50 ± 10% whereby the samples to be tested were climatised in the room for at least two hours before the tests.

One of the rear elastic side panels 26 was firstly cut from the absorbent article 10 such that a test sample comprising the rear elastic side panel 26 and about 4 cm of the chassis

20 was obtained. In addition, the test sample comprised the first fastening member 30 attached to the rear elastic side panel 26 (figure 4a). The test sample was clamped in the upper and lower clamps 29a and 29b, respectively, of the tensile testing machine, whereby the upper clamp 29a was arranged to move vertically and the lower clamp 29b was arranged to remain stationary during the test. The edge of the upper clamp 29a was

25 positioned at the innermost end of the first fastening member 30 and the edge of the lower clamp 29b was positioned at the outermost edge of the chassis part as shown in figure 4a. The test sample was centred and fastened perpendicularly in the clamps 29a, 29b. The elastic region 27 of the rear elastic side panel 26 was centred between the clamps 29a, 29b. The initial tensioning distance was 40 mm, i.e. the distance between the clamps

30 29a, 29b was initially 40 mm. Thus, the initial length of the test sample between the edges of the clamps 29a, 29b, i.e. the initial gauge length, L₀, was also 40 mm. The initial tensioning distance was measured with a ruler. Thereafter three load/unload cycles between 0 and 7N were performed. During one load/unload cycle the upper clamp 29a was moved vertically upwards until the load was 7N (load phase) and was then moved

35 vertically downwards until the load was ON (unload phase). During the load phase of the first cycle, the elongation of the initial gauge length, L₀, was measured at 1 N, 2N, 3N, 4N, 5N, 6N and 7N by measuring the change of the initial tensioning distance (i.e. by measuring the change of the distance between the clamps 29a, 29b) at those forces. In addition, during the unload phase of the third cycle, the elongation of the initial gauge 5 length, L₀, was measured at 7N, 6N, 5N, 4N, 3N, 2N and 1 N by measuring the change of the initial tensioning distance (i.e. by measuring the change of the distance between the clamps 29a, 29b) at those forces. The upper clamp 29a was moved at a constant speed of 300 mm/min.

10 The test was carried out on rear elastic side panels 26 from two different embodiments of the absorbent article 10 according to the invention denoted Embodiment I (Emb I) and Embodiment Il (Emb II). The two embodiments had the following features:

Emb I: The absorbent article 10 according to Emb I was a diaper intended for infants and

15 corresponded to the embodiment shown in figures 1 and 2 except for concerning the fact that it did not comprise any absorbent-structure-free channels 38. It had a topsheet 13 constituted by a thermally bonded spunbound nonwoven, available from BBA Nonwovens of Sweden (supplier code 4 WH05-01 017 H) and comprising a minimum of 97% polypropylene, a maximum of 2% polyethylene, 0.3-1 % TiO₂ and a maximum of 0.6%

20 surfactant (BHQ). The backsheet 15 was constituted by a glue-laminated nonwoven/microporous film laminate available from Nuova Pansac (supplier code Mira air 37B32). The waist elastic 24 was constituted by an elastic film available from Nordenia (supplier code KC 6425.000), which comprised a cast film, coextruded in three layers; a middle layer of SBS (42 μm thick) and outer layers of polyolefin (2 x 4 μm). The elastic

25 film had a length of 90 mm in its relaxed state before it was attached to the absorbent article, it was then elongated to 140 mm and attached to the absorbent article whereby the outermost 5 to 7 mm at each end of the elastic film were not elongated, i.e. only the central portion of the elastic film had been elongated prior to the elastic film's attachment to the absorbent article. The rear elastic side panels 26 were constituted by koester

30 FlexEar PA, 1 14 gsm (koester GmbH & Co. KG, Altendorf, Germany).

Emb I was tailored as follows: the distance of the absorbent structure 14 from the rear transverse edge 12c of the rear body panel 20 (the first distance A) was 60 mm. The distance of the waist elastic 24 from the rear transverse edge 12c of the rear body panel

35 20 (the second distance B) was 20 mm. The distance of the waist elastic 24 from the absorbent structure 14 (the third distance C) was 14 mm. The distance of the waist elastic 24 from each longitudinal edge 12a, 12b of the rear body panel 20 (the fourth distance D) was 55 mm. The distance of the second transverse axis X from the rear transverse edge 12c (the fifth distance E) was 25 mm. The distance of each rear elastic side panel 26 from the rear transverse edge 12c (the sixth distance F) was 8 mm. In the relaxed state, the waist elastic 24 had a length of 93 mm in the first transverse direction T of the absorbent article 10 and a length of 25 mm in the longitudinal direction L of the absorbent article 10. The length of the elastic region 27 of each rear elastic side panel 26 was 30 mm in the transverse direction of the absorbent article 10 in a relaxed state. The length of the outermost non-elastic region 28 of each rear elastic side panel 26 was 20 mm. The length of the innermost non-elastic region 28 of each rear elastic side panel 26 was 25 mm.

In their relaxed state, the rear elastic side panels 26 had a length of 55 mm outside the chassis 12 in the first transverse direction T of the absorbent article 10 and a maximum length of 83 mm in the longitudinal direction L of the absorbent article 10.

Emb II: Embodiment Il corresponded to Emb I, except for concerning the fact that the material of the rear elastic side panels 26 was exchanged to Clopay 7001 available from Clopay Plastics Products Co., Mason, OH, USA, and the fact that the rear elastic side panels 26 had a length of 54.4 mm in the first transverse direction T of the absorbent article 10 in their relaxed state.

In addition, the same test as performed of rear elastic side panels from Emb I and Emb Il was also carried out on two commercially available infant diapers: Libero Comfort Fit manufactured by SCA and Huggies Super Flex (batch reference E052609052246) manufactured by Kimberly Clark. Huggies Super Flex was tested with an initial tensioning distance of 25 mm and of 40 mm (i.e. with an initial gauge length of 25 mm and 40 mm, respectively). Two initial tensioning distances were utilized for testing rear elastic side panels from Huggies Super Flex due to the fact that the elastic region of those rear elastic side panels has a length of 25 mm only in the transverse direction of the absorbent article. When the initial tensioning distance was 25 mm, the tested rear elastic side panel was fastened between the clamps 29a, 29b such that the initial tensioning distance corresponded to the length of the elastic region in the transverse direction of the absorbent article, i.e. the elastic region was then positioned between the clamps 29a, 29b, whereby the initial gauge length, L₀, of the test sample comprised elastic parts of the rear elastic side panel only. When the initial tensioning distance was 40 mm, the initial gauge length, L₀, of the test sample comprised the elastic region as well as non-elastic parts of the rear elastic side panels.

The Cyclic Load and Unload Test of Elastic Side Panel was carried out on one rear elastic side panel from each of twelve different absorbent articles according to Emb 1 , twelve different absorbent articles according to Emb 2, twelve different Libero Comfort Fit absorbent articles, six different Huggies Super Flex absorbent articles (initial tensioning distance 25 mm) and six different Huggies Super Flex absorbent articles (initial tensioning distance 40 mm).

The results of the Cyclic Load and Unload Test of Elastic Side Panel are presented in Tables 1 a-1j below.

Table 1 a. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Emb I during the 1 ^st load phase. In the table "elongation" means elongation of the initial gauge length.

Table 1 b. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Emb I during the 3rd unload phase. In the table "elongation" means elongation of the initial gauge length.

Table 1 c. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Emb Il during the 1 ^st load phase. In the table "elongation" means elongation of the initial gauge length.

Table 1 d. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Emb Il during the 3rd unload phase. In the table "elongation" means elongation of the initial gauge length.

Table 1 e. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Libero Comfort Fit during the 1^st load phase. In the table "elongation" means elongation of the initial gauge length.

Table 1 f. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Libero Comfort Fit during the 3rd unload phase. In the table "elongation" means elongation of the initial gauge length.

Table 1 q. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Huggies Super Flex during the 1^st load phase (initial tensioning distance 40mm). In the table "elongation" means elongation of the initial gauge length.

Table 1 h. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Huggies Super Flex during the 3rd unload phase (initial tensioning distance 40 mm). In the table "elongation" means elongation of the initial gauge length.

Table 1 i. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Huggies Super Flex during the 1^st load phase (initial tensioning distance 25mm). In the table "elongation" means elongation of the initial gauge length.

Table 1 j. Results of the Cyclic Load and Unload Test of Elastic Side Panel for rear elastic side panels of Huggies Super Flex during the 3rd unload phase (initial tensioning distance 25mm). In the table "elongation" means elongation of the initial gauge length.

Thereafter the following values were calculated:

where: L_1st7N is the average gauge length of the tested samples at 1^st load 7N (which is equal to the average tensioning distance, i.e. the distance between the edges of the clamps 29a, 29b, at 1 ^st load 7N). L₀ is the initial gauge length of the tested samples (which is equal to the initial tensioning distance, i.e. the initial distance between the edges of the clamps 29a, 29b), and

E_{1 st7N} is the average elongation of the initial gauge length of the tested samples at 1 ^st load 7N.

-3rd7N == L l-Qo +-l- E --33_rrdd7N

where: L_3rd7N is the average gauge length of the tested samples at 3rd unload 7N (which is equal to the average tensioning distance, i.e. the distance between the edges of the clamps 29a, 29b, at 3^rd unload 7N). L₀ is the initial gauge length of the tested samples (which is equal to the initial tensioning distance, i.e. the initial distance between the edges of the clamps 29a,

29b), and E_3rd7N is the average elongation of the initial gauge length of the tested samples at

3^rd unload 7N.

The tested diapers were then compared by calculating: L ΛstlN quotient Q_{1 E}SP = , and

L_n

U '3rd! N quotient Q₃ESP =

L_n

The results of the calculation of Q_I E_SP and Q_3ESP are shown in Table 2 below.

Table 2

Discussion / When the obtained results for Q_{1 ES}P and Q_3ESP for the different tested absorbent articles shown in Table 2 are compared, it is realized that Emb I and Emb Il show greater values than the samples from previous products. Accordingly, if submitted to an extending force, the elastic side panels of Emb I and Emb Il will extend to a relatively greater length than the samples from previously known products. This suggests that Emb I and Emb Il would be capable to confer to the absorbent article a greater capability to adapt to the movements of a user. Cyclic Load and Unload Test of Waist Elastic

Aim:

The aim of the Cyclic Load and Unload Test of Waist Elastic is to determine the behavior of waist elastic during cyclic loading/unloading, i.e. repeated load and unload cycles.

Test procedure:

Figure 4b schematically represents the Cyclic Load and Unload Test of Waist Elastic used to determine the behaviour of waist elastic 24 of an absorbent article 10 as illustrated in figures 1 and 2 during cyclic loading/unloading. The waist elastic 24 of an absorbent article 10 was tested using a tensile testing machine (Lloyd LRX) using a force of 1 N, 2N, 3N, 4N, 5N, 6N and 7N (cell 5ON, test speed 300 mm/min, upper clamp 60mm, lower clamp 150mm, ruler accuracy ± 0.3mm). Seven Newtons is considered to be a suitable force when applying the product on a user. The tests were carried out in a climatised room at a temperature of 23 ± 1 ⁰C, relative humidity of 50 ± 10% whereby the samples to be tested were climatised in the room for at least two hours before the tests.

A sample area was firstly cut from the absorbent article 10 such that a test sample comprising the waist elastic 24, about 30 mm of the chassis along each of the longitudinal edges of the waist elastic 24 and about 15 mm of the chassis along each of the transverse edges of the waist elastic 24 was obtained. The test sample was clamped in the upper and lower clamps 29a, 29b, respectively, whereby the upper clamp 29a was arranged to move vertically and the lower clamp 29b was arranged to remain stationary during the test. The test sample was clamped between the clamps 29a, 29b such that the waist elastic 24 was elongated/relaxed in the transverse direction of the absorbent article (fig. 4b). The test sample was centred and fastened perpendicularly in the clamps 29a, 29b. The edges of the clamps 29a, 29b were positioned such that the waist elastic 24 was centred there between and the initial tensioning distance was 70 mm, i.e. the distance between the edges of the clamps was initially 70 mm. Thus, the initial length of the test sample between the clamps, i.e. the initial gauge length, L₀, was also 70 mm. The tensioning distance was measured with a ruler. Thereafter three load/unload cycles between 0 and 7N were performed. During one load/unload cycle the upper clamp was moved vertically upwards until the load was 7N (load phase) and was then moved vertically downwards until the load was ON (unload phase). During the load phase of the first cycle, the elongation of the initial gauge length, L₀, was measured at 1 N, 2N, 3N, 4N, 5N, 6N and 7N by measuring the change of the initial tensioning distance (i.e. by measuring the change of the distance between the clamps 29a, 29b) at those forces. In addition, during the unload phase of the third cycle, the elongation of the initial gauge length, L₀, was measured at 7N, 6N, 5N, 4N, 3N, 2N and 1 N by measuring the change of the initial tensioning distance (i.e. by measuring the change of the distance between the clamps) at those forces. The upper clamp was moved at a constant speed of 300 mm/min.

The Cyclic Load and Unload Test of Waist Elastic was carried out on waist elastic from each of six different absorbent articles according to Emb I described in conjunction with the Cyclic Load and Unload Test of Elastic Side Panel, six different absorbent articles according to Emb Il described in conjunction with the Cyclic Load and Unload Test of Elastic Side Panel, six different Libero Comfort Fit absorbent articles manufactured by SCA, and six different Huggies Super Flex (batch reference E052609052246) manufactured by Kimberly Clark.

The results of the Cyclic Load and Unload Test of Waist Elastic are presented in Tables 3a-h below.

Table 3a. Results of the Cyclic Load and Unload Test of Waist Elastic of Emb I during the 1 ^st load phase. In the table "elongation" means elongation of the initial gauge length.

Table 3b. Results of the Cyclic Load and Unload Test of Waist Elastic of Emb I during the 3^rd unload phase. In the table "elongation" means elongation of the initial gauge length.

Table 3c. Results of the Cyclic Load and Unload Test of Waist Elastic of Emb Il during the 1 ^st load phase. In the table "elongation" means elongation of the initial gauge length.

Table 3d. Results of the Cyclic Load and Unload Test of Waist Elastic of Emb Il during the 3^rd unload phase. In the table "elongation" means elongation of the initial gauge length.

Table 3e. Results of the Cyclic Load and Unload Test of Waist Elastic of Libero Comfort Fit during the 1^st load phase. In the table "elongation" means elongation of the initial gauge length.

Table 3f. Results of the Cyclic Load and Unload Test of Waist Elastic of Libero Comfort Fit during the 3^rd unload phase. In the table "elongation" means elongation of the initial gauge length.

Table 3q. Results of the Cyclic Load and Unload Test of Waist Elastic of Huggies Super Flex during the 1 ^st load phase. In the table "elongation" means elongation of the initial gauge length.

Table 3h. Results of the Cyclic Load and Unload Test of Waist Elastic of Huggies Super Flex during the 3^rd unload phase. In the table "elongation" means elongation of the initial gauge length.

Thereafter the following values were calculated:

The tested diapers were then compared by calculating: L otient Λs, qu tlN Q_{1 W}E = , and

L_n The results of the calculation of Q_1WE are shown in Table 4 below.

Table 4

Discussion: When the obtained results for Q_{1 W}E for the different tested absorbent articles shown in Table 4 are compared with the results for Q_{1 ES}P of the same article, it is realized that in Emb I and Emb II, these measures of the elasticity of the side panels and the waist elastic respectively, are of the same order of magnitude. In contrast, in the previously known Libero product, the side panels are less extensible than the waist elastic. In more particular contrast, in the previously known Huggies product, the side panels are considerably less extensible than the waist elastic.

Interaction Test I

Aim: The aim of the Interaction Test I is to determine the interaction between the waist elastic and the rear elastic side panels in an absorbent article. The fit, comfort and capability to stay in place of an absorbent article depend on i.a. the interaction between the waist elastic and the rear elastic side panels.

Test procedure:

Figure 4c schematically represents the test used to determine the interaction between the waist elastic 24 and the rear elastic side panels 26 in an absorbent article 10 as illustrated in figures 1 and 2. The rear waist region 22 of an absorbent article 10 was tested using a tensile testing machine (Lloyd LRX) using a force of 7 N (cell 50 N, test speed 300 mm/min, clamps 50 mm, ruler accuracy ± 0.3mm). Seven Newtons is considered to be a suitable force when applying the product on a user. The tests were carried out in a climatised room at a temperature of 23 ± 1 ⁰C, relative humidity of 50 ± 10% whereby the samples to be tested were climatised in the room for at least two hours before the tests. The absorbent article 10 was firstly cut to obtain a rectangular test sample comprising substantially only the rear waist region 22. The positions, between which the length of the waist elastic and the rear elastic side panels, respectively, were measured, were marked. The first fastening member 30 of the rear waist section 22 were clamped in the upper and lower clamps 29a and 29b, respectively, of a tensile testing machine, whereby the upper clamp 29a was arranged to move vertically and the lower clamp 29b was arranged to remain stationary during the test. The test sample was centred and fastened perpendicularly in the clamps 29a, 29b. The edge of each clamp 29a and 29b was positioned at the outermost edge of the rear elastic side panels 26 as shown in figure 4c. The initial tensioning distance, i.e. the initial distance between the edges of the clamps, L, was 225 mm. After the test sample had been fastened between the clamps 29a and 29b, the test sample was elongated by moving the upper clamp 29a vertically upwards until the tensile force was 0.3 N. The upper clamp 29a was stopped at that position and the length of the waist elastic 24 and the rear elastic side panel 26 clamped in the upper clamp 29a, respectively, at 0.3 N in the transverse direction of the absorbent article 10 was then measured using a ruler. The length of the rear elastic side panel 26 was measured between the outermost edge (i.e. the edge at the clamp) and the longitudinal edge of the chassis. Thus, the length of the rear elastic side panel is considered to be the length of the rear elastic side panel outside the chassis. The length of the waist elastic and the rear elastic side panel, respectively, at 0.3 N is in this method considered to be their respective initial length, i.e. the length in a relaxed state. The upper clamp 29a was then moved vertically upwards at a constant speed of 300 mm/min until the tensile force was 7 N. Then the length of the waist elastic 24 and the rear elastic side panel 26 clamped in the upper clamp 29a, respectively, at 7N between the previously marked positions was measured using a ruler. The length of the rear elastic side panel 26 clamped in the lower clamp 29b was also measured at 0.3N and 7N, whereby the same result as for the rear elastic side panel clamped in the upper clamp 29a was achieved.

The following equations were used to determine the % elongation of the waist elastic 24 and rear elastic side panels 26:

Total initial length of the waist elastic 24 and rear elastic side panels 28:

LOTOT = LOWE + 2*L₀ESP where

L_0TOT is the total initial length of elastic material when the rear waist region 22 is in a relaxed state (i.e. at 0.3 N as described above),

L_OWE is the average length of the waist elastic 24 when the rear waist region 22 is in a relaxed state (i.e. at 0.3 N as described above), whereby the average length of the waist elastic 24 is calculated based on the length of the waist elastic 24 of the different tested samples in a relaxed state, and

L_0ESP is the average length of the rear elastic side panel 26 when the rear waist region 22 is in a relaxed state (i.e. at 0.3 N as described above), whereby the average length of the rear elastic side panel 26 is calculated based on the length of the rear elastic side panels 26 of the different tested samples in a relaxed state.

Total length of the waist elastic 24 and the rear elastic side panels 26 at 7N:

L7NTOT = L7NWE + 2*L7NESP

L_7NTOT is the total length of elastic material when the rear waist region 22 is subjected to a force of 7N,

L_7NWE is the average length of the waist elastic 24 when the rear waist region 22 is subjected to a force of 7N, whereby the average length of the waist elastic 24 is calculated based on the length of the waist elastic 24 of the different tested samples at

7N, and

L_7NESP is the average length of the rear elastic side panel 26 when the rear waist region 22 is subjected to a force of 7N, whereby the average length of the rear elastic side panel 26 is calculated based on the length of the rear elastic side panels 26 of the different tested samples at 7N.

% elongation of the waist elastic, %WE = ^L™^{WE L}°^{WE *}100

% elongation of one rear elastic side panel of an absorbent article, %ESP = -(100 - %WE)

% elongation of both rear elastic side panels of an absorbent article, %2ESP = (100 - %WE)

In accordance with the equations above, "% elongation of the waist elastic" (%WE) is the proportion of the total elongation of the elastic materials (i.e. the rear elastic side panels and the waist region) that the elongation of the waist elastic constitutes. In other words, %WE is a waist elastic proportion of the total elongation of the rear elastic side panels and the waist elastic. Thereby, %WE is the percent contribution of the elongation of the waist elastic to the total elongation of the two rear elastic side panels and the waist elastic.

In accordance with the equations above, "% elongation of both rear elastic side panels of an absorbent article" (%2ESP) is the proportion of the total elongation of the elastic materials (i.e. the rear elastic side panels and the waist region) that the elongation of the two rear elastic side panels of an absorbent article constitutes. In other words, %2ESP is an elastic side panel proportion of the total elongation of the rear elastic side panels and the waist elastic. Thereby, %2ESP is the percent contribution of the elongation of the two rear elastic side panels to the total elongation of the two rear elastic side panels and the waist elastic.

The test was carried out on the two embodiments of the absorbent article 10 denoted Embodiment I (Emb I) and Embodiment Il (Emb II), which are described in conjunction with the Cyclic Load and Unload Test of Elastic Side Panel. In addition, the same test as performed of Emb I and Emb Il was also carried out on two commercially available infant diapers: Libero Comfort Fit manufactured by SCA and Huggies Super Flex (batch reference E052609052246) manufactured by Kimberly Clark.

The test was carried out on five samples from each of Emb I, Emb II, Libero Comfort Fit and Huggies Super Flex.

The results of the Interaction Test I are presented in Tables 5 and 6 below. Table 5

Table 6

%2ESP

The tested diapers were compared by calculating quotient Q₂ =

%WE The results of the calculation of Q₂ are shown in Table 7 below.

Table 7

Discussion: In general terms, the measure Q₂ indicates the contribution of the two elastic side panels to the total extension of the waist elastic and the elastic side panels in relation to the contribution of the waist elastic to the total extension of the waist elastic and the elastic side panels. Although there could be other regions of the rear waist region which extend somewhat when the article is stretched, the total extension of the waist elastic and the elastic side panels will form the major part of the total extension of the entire rear waist region. When the obtained results for Q₂ for the different tested absorbent articles shown in Table 7 are compared, it is realized that in the Huggies product, only a very small portion of the total extension of the rear waist region is caused by extension of the side panels, and that the majority of the extension is caused by extension of the waist elastic. In the Libero product, the majority of the total extension of the rear waist region still results from extension of the waist elastic, although the side panels are considerably more extended than in the Huggies product. Hence, the previously known products rely heavily on the extensibility of the waist region. However, in Emb II, the measure Q₂ is close to 1 , indicating that approximately half of the total rear waist region expansion results from expansion of the two side panels, and the other half from the waist elastic. This means that the contribution of the side panels to the total extension of the rear waist region of the product is considerably greater than in the previously known product. In Emb I, the balance is even more altered to the side of the side panels, in that the contribution of the two side panels to the total extension of the rear waist region of the product is greater than the contribution of the waist elastic to the total extension. Hence, Emb I and Emb Il differ greatly from the previously known products, indicating a new type of behaviour of the articles when worn.

Interaction Test Il Aim:

The aim of the Interaction Test Il is to determine the interaction between the waist elastic and the rear elastic side panels in an absorbent article. More specifically, the aim of the Interaction Test Il is to determine the elongation of the rear elastic side panels and the waist elastic at different applied forces in order to demonstrate the behaviour of the article when the waist portion thereof is stretched, e.g. the order in which the waist elastic and the side panels, respectively, comes into action. The fit, comfort and capability to stay in place of an absorbent article depend on i.a. the interaction between the waist elastic and the rear elastic side panels.

Test procedure:

The rear waist region 22 of an absorbent article 10 was tested using a tensile testing machine (Lloyd LRX) using a force of 7 N (cell 50 N, test speed 300 mm/min, clamps 50 mm, ruler accuracy ± 0.3mm). Seven Newtons is considered to be a suitable force when applying the product on a user. The tests were carried out in a climatised room at a temperature of 23 ± 1 ⁰C, relative humidity of 50 ± 10% whereby the samples to be tested were climatised in the room for at least two hours before the tests.

The absorbent article 10 was firstly cut to obtain a rectangular test sample comprising substantially only the rear waist region 22. The positions, between which the length of the waist elastic and the rear elastic side panels, respectively, were measured, were marked. The first fastening member 30 of the rear waist section 22 were clamped in the upper and lower clamps 29a and 29b, respectively, of a tensile testing machine, whereby the upper clamp 29a was arranged to move vertically and the lower clamp 29b was arranged to remain stationary during the test. The test sample was centred and fastened perpendicularly in the clamps 29a, 29b. The edge of each clamp 29a and 29b was positioned at the outermost edge of the rear elastic side panels 26 in the same way as shown in figure 4c. The initial tensioning distance, i.e. the distance between the clamps, was 225 mm. After the test sample had been fastened between the clamps 29a and 29b, the test sample was elongated by moving the upper clamp 29a vertically upwards until the tensile force was 0.3 N. The upper clamp 29a was stopped at that position and the length of the waist elastic 24 and the rear elastic side panel 26 clamped in the upper clamp 29a, respectively, at 0.3 N in the transverse direction of the absorbent article 10 was then measured using a ruler. The length of the rear elastic side panel 26 was measured between the outermost edge (i.e. the edge at the clamp) and the longitudinal edge of the chassis. Thus, the length of the rear elastic side panel is considered to be the length of the rear elastic side panel outside the chassis. The length of the waist elastic and the rear elastic side panel, respectively, at 0.3 N is in this method considered to be their respective initial length, i.e. the length in a relaxed state. The upper clamp 29a was then moved vertically upwards at a constant speed of 300 mm/min. During the movement of the upper clamp 29a, it was stopped at 2N, 4N and 7N and the length of the waist elastic 24 and the rear elastic side panel 26 clamped in the upper clamp 29a, respectively, was measured using a ruler between the previously marked positions. The length of the rear elastic side panel 26 clamped in the lower clamp 29b was also measured at 0.3N and 7N, whereby the same result as for the rear elastic side panel clamped in the upper clamp 29a was achieved.

The percent elongation of the waist elastic 24 in relation to the initial length of the waist elastic 24 at 2N, 4N and 7N were calculated using the following equations:

%E_2NWE = ^L^ ^{~ L}°^ ^* 100

^OWE

* _nn

o/ p L_1NWE L_0WE * . _nn /ot7NWE = • UU

'-'OWE

where:

L_OWE = the initial length of the waist elastic (i.e. at 0.3 N as described above) L_2NWE = the length of the waist elastic at 2N L₄NWE = the length of the waist elastic at 4N L₇NWE = the length of the waist elastic at 7N The percent elongation of one rear elastic side panel 26 in relation to the initial length of the rear elastic side panel 26 at 2N, 4N and 7N were calculated using the following equations:

_c o/ _iz L_2NESP - L_{0ESp t}

5 /ob2NESP = T UU

^OESP

^ANESP ^OESP * -i riri -4NESP = " I UU

-i riri

0 where:

L_0ESP = the initial length of one rear elastic side panel (i.e. at 0.3 N as described above)

L_2NESP = the length of one rear elastic side panel at 2N

U_NE_SP = the length of one rear elastic side panel at 4N 5 L_7NESP = the length of one rear elastic side panel at 7N

The test was carried out on the two embodiments of the absorbent article 10 denoted Embodiment I (Emb I) and Embodiment Il (Emb II), which are described in conjunction with the Cyclic Load and Unload Test of Elastic Side Panel. In addition, the same test as0 performed of Emb I and Emb Il was also carried out on one commercially available infant diaper: Huggies Super Flex (batch reference E052609052246) manufactured by Kimberly Clark.

The test was carried out on three samples from each of Emb I, Emb Il and Huggies Super5 Flex.

The results of the Interaction Test II, i.e. the average of %E_2NWE, %E_4NWE, %E_7NWE, %E₂NESP, %E_4NEsp and %E_7NESP, respectively, are presented in Table 8 below. The respective average values are calculated based on the respective values for the different0 tested samples. Table 8

Discussion / When comparing the obtained results of the average percent elongation of the waist elastic and the rear elastic side panel presented in Table 8, it is found that in the Huggies product, during initial extension (2N), virtually only the waist elastic extends. Also later on during extension, (4N and 7N) the percent elongation of the waist elastic is considerably greater than the percent elongation of the side panels. Turning to Emb I, we find that, initially (2N), the percent elongation of the waist elastic and the percent elongation of side panels are about the same. Therafter, in a middle phase of extension (4N), the percent elongation of the waist elastic is greater than the percent elongation of the side panels. At the end of the extension of the waist region (7N), the percent elongation of the waist elastic is smaller than the percent elongation of the side panels. This means that, although the contribution of the side panels to the total extension of the rear waist region is considerable, the waist elastic will generally be extended to a substantial amount thereof before the side panels will extend substantially. The same applies for Emb II, where it is found that the waist elastic has a greater percent elongation than that of the side panels both during initial and mid-phase extension (2N and 4N). However, at the end of the total extension of the rear waist region (7N), the side panels have come into action, and their percent elongation have increased substantially since the initial phase.

Hence, it is demonstrated how the articles of Emb I and Emb Il succeed in providing side panels which are elastic so as to give a considerable contribution to the total extension of the waist area, whilst still ensuring that the waist elastic is generally extended "first", before the side panels. As discussed above, to ensure that the waist elastic is tensioned first is important in order to ensure the sealing of the diaper against leakage towards the back. (It is understood that, if the elasticity of the side panels were exaggerated in relation to the waist elastic, there is a risk that the waist elastic would not come into function at all.)

Cyclic Waist Expansion Test Aim:

The aim of the Cyclic Waist Expansion Test is to determine the vertical movement of an absorbent article arranged around a test equipment simulating a human user^'s waist, whereby the vertical movement after a number of expansion/contraction cycles of the test equipment is measured. The Cyclic Waist Expansion Test is utilized in order to simulate the capability of the absorbent article to stay in place during normal use.

Test procedure:

Figure 5 shows a test sample constituted substantially of only the rear waist region 22 of an absorbent article according to an embodiment of the invention being tested on a tensile testing machine to determine a length, L_7N, prior to testing absorbent articles of the same size and type on the Cyclic Waist Expansion Test Apparatus. The test sample 22 is clamped between the upper and lower clamps 29a and 29b of a tensile testing machine as shown in figure 5. The edge of each clamp 29a and 29b is namely positioned at the innermost edge of the first fastening means 31. The upper clamp 29a is then moved vertically upwards at a constant speed of 300 mm/min until the tensile force is 7 N. The total length of the test sample at 7N, L_7N, is then measured. This test procedure is similar to the test procedure used in the Interaction Test I described above. The only difference is the position of the clamps.

Figure 6 schematically shows a perspective view of the Cyclic Waist Expansion Test Apparatus 48 according to an embodiment of the invention. The test equipment 48 comprises a stand 50 that supports two contoured plates 52, 54 which are formed to mechanically simulate a human user's waist. The contoured plates 52, 54 are supported by the stand 50 in such a way that the stand 50 does not hinder any part of an absorbent article from being wrapped around the contoured plates 52, 54. An absorbent article 10 is wrapped around the contoured plates 52, 54 and the rear elastic side panels 26 are fastened to the external surface of the front body panel 16 of the absorbent article 10 in a stretched position, as will be described below. Figure 7 shows the Cyclic Waist Expansion Test Apparatus 48 from above. Once the absorbent article has been fastened around the contoured plates 52, 54, actuating means 56 force the second contoured plate 54 away from the first contoured plate 52 from its initial position X1 to an outer position X2 (using an air pressure of 3.7-4 bar) and then back to its initial position X1 (which constitutes one expansion/contraction cycle) a number of times so as to simulate the expansion and contraction of a user's waist as he/she moves. The apparatus' mechanical motion speed (V) is set to 15 cycles per 22 seconds and there is no pause between cycles.

Figures 8 and 9 show cross-sections of the Cyclic Waist Expansion Test Apparatus 48 (as viewed in the vertical plane A-A shown in figure 6). The contoured plates 52, 54 are shown in their initial position X1 and when the contoured plates 52, 54 are positioned apart at position X2 respectively. The first fixed contoured plate 52, which incorporates a cylinder 58, is mounted directly on the stand 50. The second movable contoured plate 54 incorporates a piston 56 that is moved into and out of the cylinder 58 and is free to move with respect to the first fixed contoured plate 52. The actuating means 58, 56 may comprise a pneumatic or hydraulic cylinder or piston, as in the illustrated embodiment, or any other means for moving the two contoured plates 52, 54 together and apart. One or more support rods for supporting the second contoured plate 54 may be provided between the contoured plates 52, 54 to support the second contoured plate 54 as it moves.

Figures 10 and 1 1 schematically show the two contoured plates 52, 54, of the Cyclic Waist Expansion Test Apparatus 48 from the side and from above respectively. The first and second contoured plates 52, 54 have a substantially semi-circular cross-section and are constituted of half circles of outer radius 80.2 mm, resulting in a circumference of 504 mm when the contoured plates 52, 54 are located adjacently to one another. The two contoured plates are assembled with the open ends of their respective semi-circular- shaped cross sections facing one another so as to form a substantially circular shape resembling the shape of a human waist, especially a baby's waist. The second contoured plate 54 is moved through a predetermined distance from an inner position X1 to an outer position X2 mechanically. This predetermined distance is 10 mm when carrying out the Cyclic Waist Expansion Test, giving a circumference change of 20 mm. Both contoured plates 52, 54 have a height of 150 mm, comprise austenitic stainless steel (DIN 1 .4301 , SIS 2333, AISI 304) having a grain size of 0.3 μm and their surface is covered with a polyethylene terepthalate material, namely Scrynel Petex^® PET59HC which is available from Sefar AG, Mesh & Technology, 8803 Rϋschlikon, Switzerland under Sefar AG product reference number 07-59/33 which has a mesh opening of 59 μm, an open area of 33%, a mesh count, warp of 97n/cm, a mesh count, weft of 97 n/cm, a yarn diameter, warp of 44 μm, a yarn diameter, weft of 44 μm, a weight of 35 g/m² and a thickness of 65 μm. This material is adhered to the contoured plates using double-sided adhesive. One side of the material is coated with adhesive over its entire surface apart from a 2-3 mm wide zone along its edges (in order to eliminate the risk of adhesive coating the side of the material that will constitute the outer surface of the Cyclic Waist Expansion Test apparatus to which absorbent articles will be fastened) and the material is then stuck onto the contoured plates.

When the contoured plates 52, 54 are in their inner position X1 there is a distance of 5 mm between them. Such a distance is necessary to ensure that absorbent articles are not clamped between the contoured plates. If the shortest distance between the two contoured plates were 0 mm, there would be a risk of the absorbent articles getting stuck in the nip between the two contoured plates instead of falling therefrom once their elastic regions had been permanently deformed.

The Cyclic Waist Expansion Test comprises the steps of:

• Ensuring that the second contoured plate 54 is set at its inner position X1 .

• Unfolding the absorbent article 10 and positioning the front transverse edge 12d of a front body panel 16 parallel to the upper edge of the first contoured plate 52 and

32 mm therefrom, whereby the vertical position of the front transverse edge 12d may be marked on the first contoured plate.

• Wrapping the hanging crotch portion of the absorbent article 10 under the contoured plates 52, 54 and fastening the front body panel 16 to the rear body panel 20 so that the middle of the front transverse edge 12d of the front body panel 16 of the absorbent article 10 is located in between the contoured plates 52, 54 of the Cyclic Waist Expansion Test apparatus. The front and rear body panels 16, 20 may be temporarily held in place on the contoured plates using clamps. It is important to ensure that the waist elastic 24 and the rear elastic side panels 26 are elongated by the amount that they would be if subjected to a force of 7N on the tensile testing apparatus and that the waist elastic 24 and the rear elastic side panels 26 of all of the absorbent articles being tested are stretched by the same amount. This is done by determining the length L_7N, of each absorbent article 10, using the method described above in conjunction with figure 5, and then fastening the absorbent article 10 around the contoured plates 52, 54 so that is has a circumference equal to the tensioning distance. The tensioning distance, L, which is measured between the innermost edges of the first fastening means 31 when attached to the complementary second fastening means 32 (as indicated in figure 12), may be calculated using the equation; L = C - L_1N where C is the circumference of the contoured plates, namely 504 mm and L_7N is the length of the rear waist region 22 of that absorbent article 22 when subjected to a force of 7N on the tensile testing apparatus described herein.

• Putting a weight 10Og (namely a brass ring 36 having an outer diameter of 47 mm, and inner diameter of 35 mm and a height of 13mm) inside the crotch portion of the absorbent article. The weight 36 is placed just forward of the centre of the absorbent structure 14 of the absorbent article 10 in the front body panel 16 of the absorbent article 10 (as shown in figure 13). If clamps have been used, these are then removed. • Starting the pneumatic cylinder and letting the two contoured plates 52, 54 move through fifteen expansion and contraction cycles. When the last cycle is complete the two contoured plates 52, 54 are arranged to stop at the inner position X1 at a distance 5 mm apart.

• Marking or noting the position of the front transverse edge 12d of the absorbent article thirty seconds after the fifteenth expansion and contraction cycle has been completed and measuring/calculating the vertical distance between the first and second marks or positions, thus providing the distance through which the absorbent article has slipped if the absorbent article still remains on the Cyclic Waist Expansion Test.

The measurement of the distance each absorbent article had slipped was made within 5- 10 seconds after the completion of the fifteen expansion/contraction cycles. The measurement is taken at the middle of the front transverse edge 12d of the front body panel 16 of the absorbent article. An absorbent article or its packaging may then be marked with information and/or a parameter that is indicative of how well the absorbent article stays in place on a user's waist when in use.

Figure 12 shows an absorbent article 10 fastened around the test equipment. The test equipment may comprise a vertical scale 68 so that the initial position of an edge of a waist region 18, 22 of the absorbent article 10 may be recorded as well as its position after each, or all of the expansion and contraction cycles. The actuating means may then move the contoured plates 52, 54 through fifteen expansion and contraction cycles for example (where one such cycle involves moving the movable contoured plate 54 from X1 to X2 and back to X1 again). The tensioning distance, L, has been indicated in figure 12.

A number of samples of each of Embodiment 1 and Embodiment 2 of the absorbent article described in conjunction with the Cyclic Load and Unload Test of Elastic Side Panel were tested under the same conditions and according to the Cyclic Waist Expansion Test. In addition, two commercially available products, Libero Comfort Fit manufactured by SCA and Huggies Super Flex (batch reference E052609052246) manufactured by Kimberly Clark were tested according to the Cyclic Waist Expansion Test. The tests were carried out in a climatised room at a temperature of 23 ± 1 ⁰C, relative humidity of 50 ± 10% whereby the samples to be tested were climatised in the room for at least two hours before the tests.

The following Tables 9a-d show the vertical distance that each tested absorbent article slipped during the test and the average vertical distance of each set of tested absorbent articles.

Table 9a: Table 9b:

Embodiment I of the inventive article Embodiment Il of the inventive article Tensioning distance L= 77 mm Tensioning distance L= 96 mm Size 4 Size 4

Average 6

Std 1 .4

Average 5.7 Min 3.0

Std 1 .5 Max 8.0

15

Min 3.0

Max 8.0

Table 9c: Table 9d:

Libero Comfort Fit Huggies Super Flex

Tensioning distance L = 123 mm Tensioning distance L = 143 mm

Size 4 Size 4

Average 6.5 Std 1.4 Min 5.0 15 Max 9.0

Average 11.8 Std 1.7 Min 10.0 Max 15.0

Discussion / When comparing the obtained results of the vertical distance that the different tested absorbent articles slip during the test, it is realized the articles according to Emb I and Emb Il provide good results indicating a good fit with low risk of slip down when in use. The results of Emb I and Emb Il are slightly better than that of the previous Libero Product, and considerably better than that of the tested Huggies product. Hence, although as shown in previous tests, the articles of Emb I and Emb Il provide for greater adaptation to the user's movement in that the side panels are rendered more extensible than in previous products, the articles does not suffer from disadvantages of increased slip down. The fit of the diaper in this test is dependent on the elastic properties of the waist elastic and the elastic side panels as well as the synergistic effects of them both. Permanent Deformation Test

Aim:

The aim of the Permanent Deformation Test is to determine the permanent deformation of a rear elastic side panel after repeated load and unload cycles. Permanent deformation is defined as the extension of the material after it has been exposed to a repeated elongation and relaxation.

Test procedure:

The rear elastic side panel 26 of an absorbent article 10 as shown in figures 1 and 2 was tested using a tensile testing machine (Lloyd LRX). The tensile tester was calibrated according to the apparatus instructions. The parameters needed for the test (load and unload forces) were adjusted to: Crosshead speed: 500 mm/min Clamp distance: 40 mm

The tests were carried out in a climatised room at a temperature of 23 ± 1 ⁰C, relative humidity of 50 ± 10% whereby the samples to be tested were climatised in the room for at least two hours before the tests.

One of the rear elastic side panels 26 was firstly cut from the absorbent article 10 such that a test sample comprising the rear elastic side panel 26 and about 4 cm of the chassis was obtained. In addition, the test sample comprised the fastening member 30 attached to the rear elastic side panel 26. The test sample was clamped between the upper and lower clamps 29a and 29b of the tensile testing machine in the same way as shown in figure 4a, whereby the upper clamp 29a was arranged to move vertically and the lower clamp 29b was arranged to remain stationary during the test. The upper clamp 29a was 60 mm and the lower clamp was 150 mm. The edge of the upper clamp 29a was positioned at the innermost end of the first fastening member 30 and the edge of the lower clamp 29b was positioned at the outermost edge of the chassis part as shown in figure 4a. The test sample was centred and fastened perpendicularly in the clamps 29a, 29b. The elastic region 27 of the rear elastic side panel 26 was centred between the clamps 29a, 29b. The initial tensioning distance of the test sample was 40 mm, i.e. the distance between the clamps 29a, 29b was 40 mm. Thus, the initial length of the test sample between the edges of the clamps 29a, 29b, i.e. the initial gauge length, L₀, was also 40 mm. The tensioning distance was measured with a ruler. A predetermined number of cycles between 0 and the predetermined elongation, equal to the highest defined 1^st load force, were performed. The performed number of cycles was 3 and the predetermined elongation was 100% of the initial gauge length, L₀. During the first load phase the speed of the upper clamp 29a was 50 mm/min until a force of 0.1 N was obtained. Thereafter the upper clamp 29a was moved with a constant speed of 500 mm/min. Before the last cycle the sample was allowed to relax for one minute, and then the permanent deformation was measured by stretching the sample until a force of 0.1 N was detected, whereby the permanent elongation, E_PERM, of the initial gauge length, L₀, at 0.1 N was read.

The test was carried out on rear elastic side panels 26 from the two different embodiments of the absorbent article 10 according to the invention denoted Embodiment I (Emb I) and Embodiment Il (Emb II) described in conjunction with the Cyclic Load and Unload Test of Elastic Side Panel. In addition, the same test as performed of Emb I and Emb Il was also carried out on rear elastic side panels from two commercially available infant diapers: Libero Comfort Fit manufactured by SCA and Huggies Super Flex (batch reference E052609052246) manufactured by Kimberly Clark.

The test was carried out on six samples of each of the tested diapers. However, results were only obtained for one sample of Huggies Super Flex.

The resulting permanent deformation (%), D_PERM, is calculated based on the following equation:

U -'PpEERRMM == * 1UU

L_n

and the resulting average of D_PERM, which is calculated based on the tested samples of the different tested diapers, is shown in Table 10. Table 10

Discussion / When the obtained results for E_PERM shown in Table 10 are compared, it is realized that the permanent deformation of Emb I and Emb Il are small compared to the tested Libero and Huggies products. A low permanent deformation value indicates that the article is resistant against wear, i.e. that the advantageous properties of the product will be maintained through a period of wear and/or through a number of openings and closings of the article, such as e.g. for checking whether the article needs changing.

Elasticity Test

Aim:

The aim of the Elasticity Test is to measure how an elastic material behaves during repeated load and unload cycles.

Test procedure:

The test sample is stretched to a predetermined elongation and a cyclic movement between 0 and said predetermined elongation is performed. Desired load and unload forces are recorded. The permanent, i.e. remaining, elongation of the relaxed material is measured.

A tensile tester, Lloyd LRX, able to perform cyclic movements and equipped with a printer/plotter or software presentation is used. The test sample is prepared by cutting it to a width of 25 mm and a length that is preferably 20 mm longer than the distance between the clamps in the tensile tester. The tensile tester is calibrated according to the apparatus instructions. The parameters needed for the test (load and unload forces) are adjusted to: Crosshead speed: 500 mm/min Clamp distance: 50 mm

The test sample is placed in the clamps according to the marks and it is made sure that the test sample is centred and fastened perpendicularly in the clamps. The tensile tester is started and three cycles between 0 and the predetermined elongation, equal to the highest defined first load, are performed. Before the last cycle, the test sample is relaxed for one minute, then the permanent elongation is measured by stretching the test sample until a force of 0.1 N is detected and the elongation is read.

An "elastic material" or "elastic region" is herein defined as a material or region having a permanent elongation after relaxation of less than 10% after the material has been subjected to an elongation of 30%. An elongation of 30% means an elongation to a length that is 30% longer than the initial length of the sample. An "inelastic material" or "inelastic region" is herein defined as a material or region having a permanent elongation after relaxation of more than 10% after having been subjected to an elongation of 30%.

The invention has been described with reference to the embodied figures. However, the invention is not limited to the above-described embodiments alone. Features from one or more of the above embodiments or variants thereof may be combined as required, and the ultimate scope of the invention should be understood as being defined in the appended claims.

Claims

1 . An absorbent article (10) comprising: a chassis (12) extending about a longitudinal axis (L), said chassis including a liquid permeable topsheet (13), a liquid impermeable backsheet (15) and an absorbent structure (14) disposed between said topsheet (13) and said backsheet (15), said chassis (12) having a first transverse axis (T) dividing the absorbent article (10) into a front body panel (16) terminating in a front waist region (18) and a rear body panel (20) terminating in a rear waist region (22), said chassis (12) being delimited by opposed longitudinal edges (12a, 12b) and opposed rear and front transverse edges (12c, 12d); a pair of opposed rear elastic side panels (26) attached to said chassis (12) at said rear waist region (22) of said rear body panel (20), each rear elastic side panel (26) extending outwardly from the respective longitudinal edge (12a, 12b) of the chassis (12), and a fastening system for fastening the absorbent article (10) around the waist of a user, the fastening system comprising a first fastening member (30) with first fastening means (31 ) arranged on each opposed rear elastic side panel (26) and complementary second fastening means (32) arranged on said front body panel (16), whereby in said rear waist region (22), said absorbent structure (14) terminates at a first distance (A) from said rear transverse edge (12c) and a waist elastic (24) is arranged to extend substantially parallel to said rear transverse edge (12c) and spaced therefrom by a second distance (B) and spaced from said absorbent structure (14) by a third distance (C), said waist elastic (24) terminating short of the longitudinal edges (12a, 12b) by a fourth distance (D), characterized in,

- that said rear elastic side panels (26) and said waist elastic (24) are tailored such that, when said rear waist region (22) is in a substantially maximum extended state, the relative extension of the rear elastic side panels (26) is approximately the same as or greater than the relative extension of the waist elastic (24), and - that said first fastening means (31 ) of the rear elastic side panels (26) are positioned on a second transverse axis (X) extending substantially parallel to said first transverse axis (T), with said second transverse axis (X) passing through said waist elastic (24), such that, during extension of said rear waist region (22) from its relaxed state to a substantially maximum extended state, said waist elastic (24) will reach a substantial proportion of its maximum relative extension before said rear elastic side panels (26) reach the same substantial proportion of their maximum relative extension from their relaxed state.

2. An absorbent article according to claim 1 , characterized in, that the contribution of the elongation of the two rear elastic side panels (26) to the total elongation of the two rear elastic side panels (26) and the waist elastic (24), when the rear waist region (22) is in its maximum extended state, is substantially equal to or greater than the contribution of the elongation of the waist elastic (24) to the total elongation of the two rear elastic side panels (26) and the waist elastic (24).

3. An absorbent article (10) according to claim 1 or 2, characterized in, that said second transverse axis (X) passes through a lower half of a longitudinal extension of said waist elastic (24).

4. An absorbent article (10) according to any one of the previous claims, characterized in, that each rear elastic side panel (26) is tailored such that when tested on a tensile testing apparatus and using a force of 7N according to the Cyclic Load and Unload Test of Elastic Side Panel as described herein, a first quotient (Qi Esp) is 1 .3-1 .8, preferably 1 .4-1 .6, wherein the first quotient (Q_I E_SP) is obtained by dividing a gauge length (L_1st7N) at 1^st load 7N with an initial gauge length (L₀).

5. An absorbent article (10) according to any one of the previous claims, characterized in, that said waist elastic (24) is tailored such that when tested on a tensile testing apparatus and using a force of 7N according to the Cyclic Load and Unload Test of Waist Elastic as described herein, a first quotient (Q_{I W}E) is 1 .3-1.8, wherein the first quotient (Q_{I W}E) is obtained by dividing a gauge length (L_1st7N) at 1 ^st load 7N with an initial gauge length (L₀).

6. An absorbent article (10) according to any one of the previous claims, characterized in, that said rear elastic side panels (26) and said waist elastic (24) are tailored such that when said rear waist region (22) is extended from its relaxed state using a tensile testing apparatus and a force of 7N according to the Interaction Test Il as described herein said waist elastic (24) is extended to a substantial proportion of its maximum length before said rear elastic side panels (26) commence to be substantially activated from their relaxed state.

7. An absorbent article (10) according to any one of the preceding claims, characterized in, that said rear elastic side panels (26) and said waist elastic (24) are tailored such that when said rear waist region (22) is tested on a tensile testing apparatus and using a force of 7N according to the Interaction Test I as described herein, a second quotient (Q₂) is 0.80-1 .70, preferably 0.90-1 .60, and most preferably 1 .35-1.60, wherein said second quotient (Q₂) is obtained by dividing: an elastic side panel proportion (%2ESP) being the percent contribution of the elongation of the two rear elastic side panels (26) to the total elongation of the two rear elastic side panels (26) and the waist elastic (24), with a waist elastic proportion (%WE) being the percent contribution of the elongation of the waist elastic (24) to the total elongation of the two rear elastic side panels (26) and the waist elastic (24).

8. An absorbent article (10) according to any one of the preceding claims, characterized in, that said waist elastic (24) is terminating in a transverse direction short of the first longitudinal edges (12b) by a fourth distance (D), preferably being in the range 30-70 mm, most preferred 40-60 mm.

9. An absorbent article (10) according to any one of the preceding claims, characterized in, that the second transverse axis (X) is located at a fifth distance (E) from the rear transverse edge (12c), said fifth distance (E) preferably being in the range 23-35 mm.

10. An absorbent article according to any one of the preceding claims, characterized in, that each rear elastic side panel (26) terminates at a sixth distance (F) from the rear transverse edge (12c), said sixth distance (F) preferably being in the range 0-10 mm, most preferred 0-2 mm.

1 1 . An absorbent article according to any one of the preceding claims, characterized in, that said waist elastic (24) has a length of 85-1 15 mm, preferably 90-1 10 mm, in the transverse direction of the absorbent article (10) in a relaxed state and/or a length of 10-50 mm, preferably 20-40 mm, in the longitudinal direction of the absorbent article (10) in a relaxed state.

12. An absorbent article according to any one of the preceding claims, characterized in, that the rear elastic side panels (26) each have a length of 40-65 mm, preferably 45-60 mm, outside said chassis (12) in the transverse direction of the absorbent article (10) in a relaxed state.

13. An absorbent article (10) according to any one of the preceding claims characterized in, that each rear elastic side panel (26) is tailored such that when tested on a tensile testing apparatus and a force of 7N according to the Cyclic Load and Unload Test as described herein, a third quotient (Q₃) is 1 .35-1 .70, preferably 1 .37-1.65, and most preferably 1 .40-1 .60, said third quotient (Q₃) being obtained by dividing a gauge length (L_3rd7N) at 3^rd unload 7N with an initial gauge length (L₀).

14. An absorbent article (10) according to any one of the preceding claims, characterized in, that each rear elastic side panel (26) is tailored such that when tested according to the Permanent Deformation Test as described herein, the permanent deformation (D_PERM) is < 6.0%, preferably < 5.5% and most preferably < 5.0%.

15. An absorbent article (10) according to any one of the preceding claims, characterized in, that said rear elastic side panels (26) and said waist elastic (24) are tailored such that when tested on a Cyclic Waist Expansion Test apparatus (48) according to the Cyclic Waist Expansion Test as described herein, the absorbent article (10) does not slip down more than 10 mm from its initial position on the Cyclic Waist Expansion Test apparatus (48) during at least 15 expansion/contraction cycles of the Cyclic Waist Expansion Test and within 5-10 seconds after being subjected to at least 15 expansion/contraction cycles of the Cyclic Waist Expansion Test.

16. An absorbent article (10) according to any one of the preceding claims, characterized in, that each rear elastic side panel (26) has at least one elastic region (27) and at least two inelastic regions (28).

17. An absorbent article (10) according to claim 16, characterized in, that each rear elastic side panel (26) is attached to said chassis (12) at one of said inelastic regions (28).

18. An absorbent article (10) according to claim 16 or 17, characterized in, that each elastic side panel (26) is made of an elastic nonwoven laminate produced by an extrusion based thermic bonding of an extruded elastic film layer (44) and two nonwoven layers (46), whereby said elastic film layer (44) is sandwiched between said nonwoven layers (46), whereby said elastic film layer (44) is covered by one of said nonwoven layers (46) on one side and by the other of said nonwoven layers (46) on an opposite side such that said sides of said elastic film layer (44) are completely covered by said respective nonwoven layers (46), whereby said elastic nonwoven laminate comprises elastic and inelastic zones, whereby each elastic region (27) of said elastic side panel (26) is constituted by an elastic zone of said laminate and each inelastic region (28) of said elastic side panel (26) is constituted by a inelastic zone of said laminate.

19. An absorbent article (10) according to any one of the preceding claims, characterized in, that said waist elastic (24) is constituted by an elastic film.

20. An absorbent article (10) comprising: a chassis (12) extending about a longitudinal axis (L), said chassis including a liquid permeable topsheet (13), a liquid impermeable backsheet (15) and an absorbent structure (14) disposed between said topsheet (13) and said backsheet (15), said chassis (12) having a first transverse axis (T) dividing the absorbent article (10) into a front body panel (16) terminating in a front waist region (18) and a rear body panel (20) terminating in a rear waist region (22), said chassis (12) being delimited by opposed longitudinal edges (12a, 12b) and opposed rear and front transverse edges (12c, 12d); a pair of opposed rear elastic side panels (26) attached to said chassis (12) at said rear waist region (22) of said rear body panel (20), each rear elastic side panel (26) extending outwardly from the respective longitudinal edge (12a, 12b) of the chassis

(12), and a fastening system for fastening the absorbent article (10) around the waist of a user, the fastening system comprising a first fastening member (30) with first fastening means (31 ) arranged on each opposed rear elastic side panel (26) and complementary second fastening means (32) arranged on said front body panel (16), whereby in said rear waist region (22), said absorbent structure (14) terminates at a first distance (A) from said rear transverse edge (12c) and a waist elastic (24) is arranged to extend substantially parallel to said rear transverse edge (12c) and spaced therefrom by a second distance (B) and spaced from said absorbent structure (14) by a third distance (C), said waist elastic (24) terminating short of the first longitudinal edges (12a, 12b) by a fourth distance (D), said waist elastic (24) is tailored such that when tested on a tensile testing apparatus and using a force of 7N according to the Cyclic Load and Unload Test of Waist Elastic as described herein, a first quotient (Q_{I W}E) is 1 .3-1 .8, wherein the first quotient (Q_{I W}E) is obtained by dividing a gauge length (L_1st7N) at 1^st load 7N with an initial gauge length

(Lo), characterized in, that said first fastening means (31 ) of the rear elastic side panels (26) are positioned on a second transverse axis (X) extending substantially parallel to said first transverse axis (T), with said second transverse axis (X) passing through said waist elastic (24), and that each rear elastic side panel (26) is tailored such that when tested on a tensile testing apparatus and using a force of 7N according to the Cyclic Load and Unload

Test as described herein, a first quotient (Q_I E_SP) is 1 .3-1 .8, preferably 1 .4-1 .6, wherein the first quotient (Q_I E_SP) is obtained by dividing a gauge length (L_1st7N) at 1^st load 7N with an initial gauge length (L₀).