KR20080039886A - Absorbent article - Google Patents

Abstract

The present invention provides an absorbent article such as a diaper, pant diaper, a sanitary pant or incontinence garment. The article comprises at least one first elastic web material which is ultrasonically welded to at least one second web material along at least one weld seam. The second web material is different to the first elastic web material and said second web material has a degree of elasticity which is different to the elasticity of the first elastic web material. According to the invention, the ultrasonic weld seam between the first elastic web material and the second web material is reinforced to have a weld strength in a direction transverse to the weld seam which is at least 5N/25.4mm. The invention particularly relates to pant-type absorbent articles.

Description

Absorbent article {ABSORBENT ARTICLE}

FIELD OF THE INVENTION The present invention relates to absorbent articles such as diapers, panty diapers, sanitary panties or incontinence garments, the articles comprising an elastic web material.

Absorbent articles such as diapers, panties, diapers, sanitary panties, or incontinence garments are conceived to have a comfortable fit for the wearer. For panty absorbent articles it is also desirable that the article can be pulled up and down at the wearer's hips to allow the wearer or caregiver to easily coat and remove the article when soiled. Such articles must combine the properties of a comfortable and good fit for the user with strength, so that the article is comfortable to the wearer and still maintains integrity when worn and during use. The most deformed and most fragile areas are the areas in which the elements contained in the absorbent article are joined together (ie, the seams of the article).

International application PCT / SE05 / 000319 discloses a disposable sanitary panty comprising an elastic web material welded and reinforced by a nonwoven strip that welds the side edges (side seams) joining the front and back portions of the article.

US 2003/0120252 describes a panty diaper with a ribbon cover attached over a side seam weld that provides an aesthetically pleasing appearance. The outer cover of this panty diaper may be an elastic material. The side seams may be bonded by an adhesive and / or by ultrasonic bonding.

There remains a need for absorbent articles that bond components together firmly and firmly, and that do not tear or separate along the seam when the article is deformed (eg, when it is worn or taken off). This has been found to be particularly important when two components with different elasticity (different stretch resistance) are joined together.

Summary of the Invention

The present invention solves the problems associated with this type of known article. More specifically, the present invention provides absorbent articles such as diapers, panty diapers, sanitary panties or incontinence garments. The article includes at least one first elastic web material, which is ultrasonically welded to the at least one second web material along at least one weld seam. The second web material is different from the first elastic web material and the second web material is inelastic or has a different degree of elasticity from that of the first elastic web material. According to the present invention, the ultrasonic welded joint between the first elastic web material and the second web material is reinforced to have a weld strength in the direction transverse to the welded joint that is at least 5N / 25.4 mm.

An absorbent article according to one embodiment of the present invention is a panty absorbent article, such as a panty diaper, sanitary panty, or incontinence panties. It includes a front part and a rear part. The front part and the rear part are joined to each other along two lengthwise side edges defining a waist opening and a pair of leg openings. At least one of the front and rear portions comprises a first elastic web material. The article also includes a crotch portion located between the front portion and the rear portion in the longitudinal direction of the article, the crotch portion comprising the second web material. The crotch is welded to the front and back portions via ultrasonic welding seams. In one embodiment of the panty-shaped absorbent article, both the front and rear portions comprise a first elastic web material.

In a further embodiment, the article comprises a front waist positioned at the edge of the front portion away from the crotch in the longitudinal direction of the article. The front portion includes the first elastic web material, while the front waist portion includes the second web material. The anterior waist is welded to the anterior part via ultrasonic welding seams. Alternatively or in addition, the panty-shaped absorbent article of the present invention may include a rear waist positioned at the edge of the rear portion away from the crotch in the longitudinal direction of the article. The rear portion includes the first elastic web material, while the rear waist portion includes the second web material. The back waist is welded to the back through ultrasonic welded seams.

Preferably, the first elastic web material of the panty absorbent article is a laminate material. The laminate material may be comprised of an elastic film layer positioned between the first and second layers of fibrous material and the first and second fibrous layers. The first elastic web material may be a bottom component of the front and rear portions and preferably at least 20%, preferably 25%, more preferably 30%, most preferably 40% of the total surface area of the absorbent article. There is a function to breathe. Typically, the elastic web material has a water vapor transmission rate according to ASTM E96-00 Procedure D of at least 1500 g / m 2 24h, preferably at least 3000 g / m 2 24h.

The second web material preferably has a lower elasticity than the elasticity of the first elastic web material. The nonwoven material is suitable for the second web material.

In addition to the foregoing, the ultrasonic weld joint between the first elastic web material and the second web material is reinforced to have a weld strength in a direction transverse to the weld joint that is at least 7 N / 25.4 mm, preferably at least 9 N / 25.4 mm. Reinforcement of the weld seam may be provided by an additional layer of web material bonded to the weld seam. The web material of this additional layer may be developed along at least 50% of the length of the welded seam to be joined, preferably along at least 75%, more preferably along at least 100%.

Alternatively, the reinforcement of the weld seam may be provided by glue applied along 50-100% of the length of the weld seam, preferably along 70-90%.

According to the present invention, the panty-shaped absorbent article also includes an absorbent assembly, the absorbent assembly comprising a liquid impermeable backsheet, a liquid permeable topsheet and an absorbent core enclosed therebetween.

1 shows a perspective view of a panty diaper.

Fig. 2 shows a plan view of the panty diaper in a flat and fully deployed state, as seen from the side facing the body.

3 is a corresponding plan view seen from the side facing the garment on the opposite side of the panty diaper.

4 is a cross-sectional view along the line Vl-Vl of FIG. 3.

FIG. 5 is a cross section through an elastic laminate along line VII-VII in FIG. 3. FIG.

6 and 7 schematically illustrate a method of measuring weld strength.

Absorbent goods

The term "absorbent article" refers to a product placed on the skin of a wearer to absorb and contain body exudates, such as urine, feces and menstrual fluid. The present invention mainly refers to disposable absorbent articles, which refers to articles which are not intended to be washed after use or otherwise stored or reused as absorbent articles. The present invention refers to a "panty-type absorbent article". Examples of such panty absorbent articles are panty diapers, sanitary panties, and incontinence panties.

The "developed state" of the article is here developed in all four directions to the extent that the article is deployed such that all the elastic material contained therein, such as elastic web material, waist elastic material, leg elastic material, does not wrinkle any part of the product. That is, the entire product is defined as being completely flat. The article is only developed to the extent that it reaches this flat state.

1 shows an embodiment of an absorbent article 1 which is a panty diaper for an infant or incontinence adult. The article includes at least one first elastic web material. This elastic web material 10 is described in detail in the following:

The elasticity of the elastic web material 10 in the x-direction should be at least 30%, preferably at least 50%, more preferably at least 70% as measured by the elasticity test specified herein. Preferably, the elastic web material 10 is also elastic in the y-direction of the article. However, the elasticity in the y-direction is preferably lower than in the x-direction. The elasticity in the y-direction should be at least 20%. Another way to characterize the elasticity of the laminate is to specify the basis weight of the elastic web material before and after stretching. In this case, a suitable elastic web material has a basis weight of about 80 g / m 2 without stretching and may be stretched to a basis weight of 65 g / m 2.

The elastic web material 10 is preferably a laminate material 9. In the embodiment illustrated in FIG. 5, the elastic web material 10 consists of first and second outer layers 11 and 12 of a fibrous material (ie, nonwoven) and is placed between the fibrous layers. It is an elastic laminate 9 composed of a film layer 13. However, it is to be understood that other forms of elastic web material may be used, such as the nonwoven material itself, which is inelastic, but a nonwoven material elasticized by an elastic yarn or the like. The elastic web material may comprise one layer or two or more layers laminated. The total basis weight of the elastic web material 10 is preferably 100 g / m 2 or less, more preferably 90 g / m 2 or less.

In the elastic laminates shown and described here, the outer fibrous layers 11 and 12 are selected so that they provide a high puncture resistance to the material in combination with the inner elastic film layer 13. They also give the laminate a soft, cloth-like feel. Examples of suitable materials are carded web and spunbond materials. The basis weight of the fibrous material layer should be 10 to 35 g / m 2, preferably 12 to 30 g / m 2, more preferably 15 to 25 g / m 2. Examples of suitable polymers for use in fibrous materials are polyethylene, polyester, polypropylene and other polyolefin homopolymers and copolymers. Natural fibers such as cotton may also be used as long as they provide the required properties. The mixture of polymers can contribute to the higher flexibility of the fibrous layers, but this gives the fibrous material a higher elongation at maximum load. Mixtures of polyethylene and polypropylene polymers have been proven to provide good results in this regard. It is also possible for the fibrous layers to comprise a mixture of fibers of different polymers.

The elastic film layer 13 is a perforated elastic film having a basis weight of 20 to 80 g / m 2, preferably 20 to 60 g / m 2, according to one embodiment of the invention. The film can be any suitable elastomer, natural or synthetic. Some examples of materials suitable for elastic films include low crystallinity polyethylene, metallocene catalyzed low crystalline polyethylene, ethylene vinyl acetate copolymers (EVA), polyurethanes, polyisoprene, butadiene-styrene copolymers, styrene / isoprene / styrene (SIS), styrene / butadiene / styrene (SBS), or styrene block copolymers such as styrene / ethylene-butadiene / styrene block copolymers. Blends of these polymers may also be used and other modified elastomeric or nonelastic polymer materials may be used. One example of a suitable film is a perforated three-layer elastomer film of PE-SEBS-PE.

The elastic laminate 9 can be prepared according to the method disclosed in WO 03/047488, where one spunbond layer 11 is applied to the film 13 in a tacky state and thus bonded to the film layer, Another spunbond layer 12 is adhesively laminated to the film layer 13 using, for example, a pressure sensitive hot melt adhesive. Alternatively, the laminate is made according to a variant of this known method, in which the laminate is stretched and stretched to a point below the elongation at at least one peak load of the inelastic nonwoven layer (engaging gears, To retain some strength for at least one of the nonwoven layers) (through IMG). The other layer may also be stretched to a point below the elongation at peak load or to a point that is torn during stretching.

The method disclosed in WO 03/047488 involves the stretching of the laminate over the breaking point of the fibrous material so that the inelastic layer is completely destroyed. Therefore, as described in WO 03/047488, the elongation of the laminate is not limited by the stretch modulus of the inelastic material.

In a preferred embodiment, at least one, preferably both fibrous layers bonded to the elastic film are not completely torn (as opposed to the method disclosed in WO 03/047488) in the manufacture of the laminate according to the invention. The selection of the fibrous material with elongation at maximum load, which is greater than the elasticity of the elastic laminate, allows the elastic film to stretch without being disturbed by the fibrous layers. This choice also ensures that the fibrous layers do not tear or break completely during manufacture, contributing to the puncture resistance of the laminate. Preferably both fibrous layers, or at least one of the fibrous layers, have an elongation at maximum load, at least 10% higher than the elasticity of the laminate. This is described in more detail in PCT / SE2004 / 001005, which is incorporated herein by reference.

The opacity of the material layer is the characteristic ability of the material layer to visually hide what the underlying object or pattern looks like. Opacity is measured in%, 100% opacity means nothing is seen through the material layer and 0% means that the material layer is completely transparent. Opacity is measured by the Opacity Test disclosed in PCT / SE2004 / 001415 based on luminescence-reflectance-factor data.

The opacity of the elastic web material 10 can be obtained by including an opaque filler in the laminate 9, specifically in the elastic film 13. Such pigments may be organic or inorganic dyes, colorants, or bleaches. Inorganic materials such as titanium dioxide, inorganic carbonates, synthetic carbonates, talc, stone, selenite, magnesium hydroxide, aluminum trihydrate, diatomaceous earth, mica, natural or synthetic silica, calcined clay and mixtures thereof are examples of preferred opaque fillers. The filler is preferably added as a master batch at the time of extrusion of the film. One example of a suitable concentration is about 5% filler by weight of the film.

The elastic web material 10 preferably has breathability (water vapor transmission) according to ASTM E96-00 Procedure D of at least 1500 g / m 2 24h, preferably at least 3000 g / m 2 24h. The open area of the elastic film layer is preferably at least 5%, more preferably at least 8%. Open area is measured by an image analysis method and is defined as the sum of the pore areas divided by the total area of the film sample.

The first elastic web material 10 is ultrasonically welded to the at least one second web material 21 along the at least one weld seam 8. This second web material 21 is described in detail in the following:

The second web material 21 must also provide a soft, cloth-like feel to the absorbent article 1. Examples of suitable materials are nonwoven materials such as carded web and spunbond materials. The basis weight of the second web material should be 10 to 35 g / m 2, preferably 12 to 30 g / m 2, more preferably 15 to 25 g / m 2. Examples of suitable polymers used in the second web material are polyethylene, polyester, polypropylene and other polyolefin homopolymers and copolymers. Natural fibers such as cotton may also be used as long as they provide the required properties. The mixture of polymers can contribute to the higher flexibility of the second web material, thereby providing the second web material 21 with a higher elongation at maximum load. Mixtures of polyethylene and polypropylene polymers have been proven to provide good results in this regard. It is also possible for the second web material 21 to comprise a mixture of fibers of other polymers. Preferably, the second web material 21 has a function of breathing.

The second web material 21 is different from the first elastic web material 10. This means that they differ in at least one feature, for example in structure, composition, texture, and the like. It is not required that the second web material 21 have a different composition than the first elastic web material 10 (ie, both may still include the same polymers in different forms). However, the second web material 21 must have a different degree of elasticity from that of the first elastic web material 10, or the second web material may be inelastic. The elasticity of the web material can be determined using the elasticity test specified herein. In one embodiment, the second web material 21 has a lower elasticity than the elasticity of the first elastic web material 10.

The ultrasonic weld joints 8, 17a, 18a between the first elastic web material 10 and the second web material 21 are reinforced to have weld strength in a direction transverse to the weld joint at least 5N / 25.4 mm. This weld strength has been found to be sufficient to ensure that the weld seam does not break under the deformations received while wearing the absorbent article 1. Preferably the ultrasonic weld joints 8, 17a, 18a between the first elastic web material 10 and the second web material 21 are transverse to the weld seam that is at least 7N / 25.4 mm, preferably at least 9N / 25.4 mm. It is reinforced to have welding strength in the direction of squeezing.

The panty diaper illustrated in FIGS. 1, 2 and 3 typically comprises a front part 5 and a rear part 6. The article has a longitudinal direction y and a transverse direction x. As can be seen in FIG. 1, the front part and the rear part are joined to each other along two two longitudinal side edges 4 defining a waist opening 15 and a pair of leg openings 16. At least one of the front and rear portions 5, 6 comprises a first elastic web material 10, as described above. The diaper also includes a crotch portion 7 located between the front portion 5 and the rear portion 6 in the longitudinal direction y of the article. The crotch portion 7 comprises the second web material 21 as described above. The crotch portion 7 is welded to the front portion 5 and the rear portion 6 via an ultrasonic welding joint 8. These ultrasonic welded joints have weld strength in the direction across the welded joint as defined above.

The front part 5 is defined by a weld seam 17a joining it to the front waist 17, a longitudinal side edge 4 of the article and a weld seam 8 joining it to the crotch 7. . In use, the anterior part 5 is located in the abdomen of the wearer. The rear portion is defined in a similar manner, namely by a welded joint 18a joining it to the rear waist 18, a longitudinal side edge 4 of the article and a welded joint 8 joining it to the crotch 7. do. The crotch is defined at the longitudinal edge by the edge of the leg opening 16 of the article and at the transverse edge by the weld seam 8 described above.

As noted above, at least one of the front and back portions 5, 6 of the article 1 comprises an elastic web material 10. Preferably, the front and rear portions 5, 6 both comprise an elastic web material 10. The elastic web material 10 is preferably the same at both the front and rear portions 5, 6, however, the elastic web material 10 may also be different at the front portion 5 and the rear portion 6. The elastic web material may be the bottom component of the front part 5 and the rear part 6 at least 20%, preferably 25%, more preferably 30%, most preferably 40% of the total surface area of the absorbent article. It may be.

The panty-shaped absorbent article 1 according to the invention may also comprise a front waist 17 which is located at the edge of the front part 5 away from the crotch part 7 in the longitudinal direction y of the article. As noted above, the front portion 5 comprises a first elastic web material 10, while the front waist 17 comprises a second web material 21. The front waist 17 is welded to the front part 5 via the ultrasonic welding joint 17a. These ultrasonic welded joints have weld strength in the direction across the welded joint as defined above.

The panty absorbent article 1 may alternatively or additionally comprise a rear waist 18 positioned at the edge of the rear portion 6 away from the crotch portion 7 in the longitudinal direction y of the article. . The rear portion 6 comprises a first elastic web material 10, while the rear waist 18 comprises a second web material 21. The rear waist 18 is welded to the rear portion 6 via an ultrasonic welding seam 18a. These ultrasonic welded joints have weld strength in the direction across the welded joint as defined above. The material of the rear waist 18 need not be the same as the material of the front waist 17.

Reinforcement of the weld seam may be provided by an additional layer of web material 14 bonded to the weld seams 8, 17a, 18a so that the weld seam achieves the required weld strength. An additional layer of web material 14 may be joined to the weld seam 8, 17a, 18a at the same time that the rest of the seam is joined-ie by ultrasonic welding. Alternatively, it can be added to the weld seam 8, 17a, 18a at a later stage, but simultaneous joining is preferred for ease of manufacture. The additional layer of web material 14 may be joined via adhesion, ultrasonic welding, thermal welding, or any other method well known to those skilled in the art for joining the two material webs. In a preferred embodiment, an additional layer of web material 14 is positioned between the first elastic web material 10 and the second web material 21 (ie sandwiched in the region of the weld seam between them). Alternatively, it may be located on the outer surface of the first elastic web material 10 or on the outer surface of the second web material 21 in the region of the weld seam. Two additional layers of web material 14 may be present, one outside of each side of the weld seam. The further layer of web material 14 develops along at least 50%, preferably along at least 75%, more preferably along at least 100% of the length of the welded seams 8, 17a, 18a to be joined. . The further layer of web material 14 is preferably a nonwoven material. Preferably, the further layer of web material 14 is a strip of material.

The additional layer of web material 14 need not be a separate piece of material bonded to the absorbent article 1. If the requirement of weld strength is met, the additional layer of web material 14 may be a component of the absorbent article at the weld. For example, the front and rear waist portions 17, 18 are typically formed from one or more web material layers. The layer of nonwoven can be folded such that the fold lines form the outer edge of the panty diaper 1 in the longitudinal direction y, while the two edges of the web material meet at the weld seams 17a and 18a. If so, it is sufficient for the purposes of the present invention that the two layers comprising the waists 17, 18 are welded to the front / rear portions 5, 6. As long as there is at least one additional layer of web material 14 in the region of the welded joint, the present invention is achieved.

The reinforcement may be provided by glue applied along 50-100% of the length of the weld seam 8, 17a, 18a, preferably along 70-90%, so that the weld strength required for the weld seam is obtained. . The glue may be applied simultaneously with the ultrasonic welding or at a later stage. If applied simultaneously with ultrasonic welding, the glue may be applied to the surfaces of the first elastic web material 10 and the second web material 21 in contact with the weld seam. Alternatively, they may be applied to one or both surfaces of the first elastic web material 10 and / or the second web material 21 which are not in contact in the weld seam. When applied at a later stage, the glue may be applied to one or both outer surfaces of the welded seams 8, 17a, 18a.

The panty absorbent article 1 according to the invention also comprises an absorbent assembly 3, which absorbs the liquid impermeable backsheet 19, the liquid permeable topsheet 20 and enclosed therebetween. An absorbent core 2 is included (FIG. 4). These components are described below:

Top sheet

The liquid permeable topsheet 20 may be composed of a nonwoven material, such as spunbond, meltblown, carded, hydroentangled, wetlaid, or the like. Suitable nonwoven materials may consist of natural fibers such as woodpulp or cotton fibers, artificial fibers such as polyester, polyethylene, polypropylene, viscose, or the like, or mixtures of natural and artificial fibers. The topsheet material may also be composed of tow fibers, which may be bonded to each other in a bonding pattern as disclosed, for example, in EP-A-1 035 818. Further examples of topsheet materials are porous foams, perforated plastic films, and the like. Suitable materials as the topsheet material should be flexible and nonirritating to the skin and intended for easy penetration of bodily fluids such as urine or menstrual fluid. The topsheet may be different in other portions of the absorbent article.

Backsheet

The liquid impermeable backsheet 19 contained in the absorbent assembly 3 on the garment facing side of the absorbent core 2 is a thin plastic film, for example a liquid impermeable material such as polyethylene or polypropylene film, liquid fire. A nonwoven material coated with a permeable material, a hydrophobic nonwoven material resistant to liquid penetration or a laminate comprising a plastic film and a nonwoven material. The backsheet 19 has a breathing function that allows it to escape vapor from the absorbent core while still not allowing liquid to pass through. Examples of backsheet materials with a breathing function are porous polymer films, nonwoven laminates from spunbond and meltblown layers, porous polymer films and laminates from nonwovens. The backsheet 19 is preferably inelastic.

Absorbent core

An "absorbent core" is an absorbent structure disposed in an absorbent assembly of an absorbent article. The absorbent core 2 can be any conventional one. Examples of commonly occurring absorbent materials are cellulose fluff pulp, tissue layers, high absorbent polymers (so-called superabsorbents), absorbent foam materials, absorbent nonwoven materials, and the like. It is common to combine cellulose fluff pulp with a superabsorbent in the absorbent core. Superabsorbent polymers are water swellable, water insoluble organic or inorganic materials capable of absorbing at least about 20 times their own weight in aqueous solutions containing 0.9 weight percent sodium chloride. Organic materials suitable for use as superabsorbents may 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 such as polyacrylic acid, polyacrylamide, polyvinyl alcohol, polyacrylate, polyacrylamide, polyvinyl pyridine, and the like. Other suitable polymers include hydrolyzed acrylonitrile graft starch, acrylic acid graft starch, and isobutylene maleic anhydride copolymers and mixtures thereof. The hydrogel polymer is preferably lightly crosslinked to render the material substantially water insoluble. Preferred superabsorbent materials are further surface crosslinked such that outer surfaces or shells of superabsorbent particles, fibers, flakes, spheres and the like have a higher crosslink density than the interior of the superabsorbent. The superabsorbent material can be in any form suitable for use with an absorbent composite including particles, fibers, flakes, spheres, and the like.

High absorption capacity is provided by the use of high amounts of superabsorbent material. For absorbent cores comprising a matrix of hydrophilic fibers such as cellulose fibers and superabsorbent material, the ratio of superabsorbent material is preferably 10 to 90% by weight, more preferably 30 to 70% by weight.

With regard to liquid receiving capacity, liquid distribution capacity and storage capacity, it is common in absorbent articles to have an absorbent core comprising layers of different properties. For example, thin absorbent bodies conventional in infant diapers and incontinence guards often include a structure made of a squeezed blend or layer of cellulose fluff pearl and superabsorbent polymer. The size and absorbent dose of the absorbent core can be varied to suit other uses such as infant or adult incontinence patients.

The absorbent core may also further comprise an acquisition distribution layer placed on top of the primary absorbent body, which is adapted to quickly receive and temporarily store the released liquid prior to being absorbed by the primary absorbent core. Such acquisition distribution layers are well known in the art and may be composed of porous fibrous waddings or foam materials.

Description of the test method

Elasticity test

The method measures how the elastic material behaves in cycles of repeated loading and unloading. The sample is stretched to a given elongation and periodic movements between zero and the given elongation are performed. Record the desired load and force at unloaded. The permanent, e.g., elongation, of the relaxed material is measured.

Use Lloyd LRX, a tension tester capable of performing periodic movements, equipped with a printer / plotter or software presentation. The sample is prepared by cutting it to a width of 25 mm and a length of preferably 20 mm longer than the distance between the clamps of the tension tester.

Test the tension tester in accordance with the device instructions. The parameters required for the test (load and unload force) are adjusted as follows:

헤드 Crosshead speed: 500 mm / min

Clamp distance: 50 mm

Before load: 0.05 N

Place the sample in the clamp along the mark and ensure that the sample is centered and clamped vertically in the clamp. Start the tension tester and perform three cycles between zero and a given elongation, such as the highest prescribed first load. The sample is allowed to relax for one minute before the last cycle, then the permanent elongation is measured and elongation is read by stretching the sample until a force of 0.1 N is detected.

Permanent elongation after relaxation should be less than 10% and measured by the method described above. Thus, 30% elasticity is defined as the laminate must have permanent relaxation after less than 10% elongation after reaching 30% elongation in the tension tester. 30% elongation refers to the elongation to 30% longer than the initial length of the sample.

Test method for measuring weld strength

Tensile strength of the welded joint is measured according to the method described in patent application PCT2004 / 001004 (reference ASTM D 882). The rectangular test specimen is cut from the absorbent article so that the reinforced weld seam extends across the specimen and substantially perpendicular to the edge of the specimen. The width of the test specimen is 25.4 mm and the length, if possible, is 50 mm longer than the distance between the clamps in the tension test instrument Instron 4301. 6 and 7 illustrate how the test specimen is mounted to the clamp of the instrument.

Although the invention has been described with reference to preferred embodiments, modifications are possible within the scope of the claims. In particular, while the present invention has been described with reference to panty-shaped absorbent articles, the features of the present invention apply equally to other absorbent articles such as diapers. Therefore, it is intended that the present invention cover any modification or equivalent within the art to which this invention pertains or which is well known in practice. The scope of the invention is defined only by the claims appended hereto.

Claims (17)

An absorbent article 10, such as a panty diaper, sanitary panty, or incontinence panty, the article comprising at least one first elastic web material 10, which is at least one along the at least one weld seam 8. Being ultrasonically welded to a second web material 21, the second web material 21 being different from the first elastic web material 10, wherein the second web material 21 is inelastic or the first elastic web. In an absorbent article having a degree of elasticity different from that of the material 10, The ultrasonic welding joints 8, 17a, 18a between the first elastic web material 10 and the second web material 21 are reinforced to have weld strength in a direction transverse to the welding joint of at least 5N / 25.4 mm. Absorbent article 1 to be used. 2. The article according to claim 1, wherein the article comprises a front portion (5) and a rear portion (6), wherein the front portion and the rear portion define two waist sides and two pairs of longitudinal sides defining a pair of leg openings (16). Bonded to one another along the edge 4, at least one of the front and rear portions 5, 6 comprises the first elastic web material 10, the article 1 being in the longitudinal direction of the article ( y) further comprising a crotch portion 7 positioned between the front portion 5 and the rear portion 6, the crotch portion 7 comprising the second web material 21, the crotch portion (7) is a panty-type absorbent article (1), characterized in that it is welded to the front portion (5) and the rear portion (6) through an ultrasonic welding joint (8). The panty-shaped absorbent article (1) according to claim 2, wherein both the front portion (5) and the rear portion (6) comprise a first elastic web material (10). 4. The article according to claim 1, wherein the article comprises a front waist 17 positioned at the edge of the front portion 5 away from the crotch portion 7 in the longitudinal direction y of the article. The front portion 5 includes the first elastic web material 10, the front waist 17 includes the second web material 21, and the front waist 17 A panty absorbent article (1) characterized in that it is welded to the front portion (5) via an ultrasonic welding joint (17a). 5. The article according to claim 1, wherein the article comprises a rear waist 18 positioned at the edge of the rear portion 6 away from the crotch portion 7 in the longitudinal direction y of the article. 6. The rear portion 6 includes the first elastic web material 10, the rear waist 18 includes the second web material 21, and the rear waist 18 A panty absorbent article (1), characterized in that it is welded to the rear portion (6) via an ultrasonic welding joint (18a). The panty absorbent article (1) according to any one of the preceding claims, characterized in that the first elastic web material (10) is a laminate material (9). 7. Laminate material 9 according to claim 6, consisting of first and second layers 11 and 12 of fibrous material and an elastic film layer 13 positioned between the first and second fibrous layers. A panty-shaped absorbent article 1 characterized by the above-mentioned. 8. The method of claim 2, wherein the first elastic web material is at least 20%, preferably 25%, more preferably 30%, most preferably 40% of the total surface area of the absorbent article. A panty absorbent article (1) characterized in that it is a bottom component of the front part (5) and the rear part (6). The panty absorbent article (1) according to any one of the preceding claims, characterized in that the first elastic web material (10) has a breathing function. 10. The method of claim 9, wherein the first elastic web material 10 has a water vapor transmission rate according to ASTM E96-00 Procedure D of at least 1500 g / m 2 24h, preferably at least 3000 g / m 2 24h. A panty type absorbent article (1). The panty absorbent article (1) according to any one of the preceding claims, characterized in that the second web material (21) has a lower elasticity than the elasticity of the first elastic web material (10). The panty absorbent article (1) according to any one of the preceding claims, characterized in that the second web material (21) is a nonwoven material. The ultrasonic welding seam 8, 17a, 18a between the first elastic web material 10 and the second web material 21 is at least 7N / 25.4 mm, preferably at least 9N /. A panty-shaped absorbent article (1), characterized in that it is reinforced to have a weld strength in a direction transverse to a weld joint of 25.4 mm. The panty absorbent article (1) according to any one of the preceding claims, wherein the reinforcement is provided by an additional layer of web material (14) bonded to the weld seam (8, 17a, 18a). 13. The additional layer of web material 14 according to claim 12, along at least 50% of the length of the welded seams 8, 17a, 18a to be joined, preferably at least 75%, more preferably at least A panty absorbent article (1) characterized by developing along 100%. 12. The reinforcement according to any one of the preceding claims, wherein the reinforcement is provided by glue applied along 50-100% of the length of the welded seams 8, 17a, 18a, preferably along 70-90%. A panty-shaped absorbent article 1 characterized by the above-mentioned. The article 1 according to any of the preceding claims, wherein the article 1 further comprises an absorbent assembly 3, the absorbent assembly 3 comprising a liquid impermeable backsheet 19, a liquid permeable topsheet 20 and A panty-shaped absorbent article (1), characterized in that it comprises an absorbent core (2) enclosed in between.

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