Method for manufacturing a pants-type disposable absorbent hygience article

Abstract

The invention relates to a method for manufacturing a pant-type disposable absorbent hygiene article (2), comprising a waist edge (20), sealed all around the periphery thereof, forming a waist opening and with leg openings (8), wherein longitudinal side edge sections (16), 18) of a front piece (6) and a back piece (4) are joined together by the manufacturer to form the waist edge (20), sealed all around the periphery thereof and the leg openings (8), and having an absorbent body (22) and elasticizing means (38) at least in the region of the leg openings (8). The aim of the invention is to improve the wearing comfort. This aim is achieved, in that, before the longitudinal side edge sections (16, 18) are joined together by the manufacturer, the hygiene article, when laid flat, is provided with a first elasticised periphery section (44), followed by a second non-elasticized periphery section (46), followed by a third elasticized periphery section (48) and followed by a fourth non-elasticized periphery section (49), extending from a longitudinal side edge (12, 14) of the front piece (6) or back piece (4) of the article, towards a crotch center line (42), along a periphery (40) of a corresponding leg opening (8).

Description

This application is a continuation of Ser. No. 11/628,467 filed Dec. 4, 2006 as the national stage of PCT/EP2005/006235 filed on Jun. 10, 2005 and also claims Paris Convention priority of DE 10 2004 032 377.1 filed on Jun. 29, 2004, the entire disclosures of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The invention concerns a method for producing a pants-type disposable absorbent hygiene article with a hip edge which is continuously closed in the peripheral direction and forms a hip opening, and with leg openings, wherein the hip edge which is continuously closed in the peripheral direction and the leg openings are formed by connecting longitudinal side edge sections of a front part and rear part to each other at the manufacturing plant, and having an absorbent body and elasticizing means at least in the area of the leg openings.

Conventional pants-type absorbent hygiene articles of this type usually comprise a plurality of elasticizing means, often in the form of rubber-elastic threads which are mostly glued to chassis materials in the pretensioned state. A hip edge area is thereby usually preferably continuously elasticized in the peripheral direction. Conventional pants-type diapers also have elasticizing means in the front and rear areas. The peripheral areas forming or surrounding the leg openings are also continuously elasticized to ensure tight fit of the hygiene article on the skin surface of the user in order to prevent lateral escape of body excretions.

Abutment of pretensioned, elasticized areas on the skin surface especially in the area of the leg openings can cause skin irritations due to friction or force exerted by the mostly thread-shaped elasticizing means. This problem is aggravated by the presence of additional moisture within the hygiene article due to body liquids or perspiration and is aggravated by increasing activity, i.e. movement of the user.

Departing therefrom, it is the underlying purpose of the present invention to provide a method for manufacturing a pants-type hygiene article of the above-mentioned kind having improved wearing comfort and, in particular, reduced skin irritation.

SUMMARY OF THE INVENTION

This object is achieved in accordance with the invention with a method for manufacturing a hygiene article of this type as recited in the independent claim.

In particular, the manufactured hygiene article has a first elasticizing peripheral section, adjacent thereto, a second non-elasticizing peripheral section, adjacent thereto, a third elasticizing peripheral section, and adjacent thereto, a fourth non-elasticizing peripheral section are provided in the flat state before connecting the longitudinal side edge sections at the manufacturing plant, extending from a longitudinal side edge of the front part or rear part of the article along the periphery of a respective leg opening towards a center crotch line.

In accordance with the invention, it is not necessary to elasticise the entire leg opening of a pants-type diaper. In view of the fact that modern hygiene articles have additional upright collar elements, so-called “cuff elements”, which extend substantially in the longitudinal direction and which form a lateral barrier for escaping liquid and solid body excretions, leg openings which are continuously elasticized in the peripheral direction no longer appear to be absolutely necessary. Since the elasticizing means gather or frill the material to which they are connected in the pretensioned state, they accumulate material in the relaxed state which may be uncomfortable e.g. during sitting. In any event, gathered or frilled areas, i.e. elasticized areas, severely rub the skin surface of the user, in particular while he/she is moving, which can cause the above-mentioned skin irritation. It has turned out in accordance with the invention that this can be counteracted by only using elasticizing means in the crotch area at locations where they are actually required. In accordance with the invention, the wearing comfort is improved in that a second non-elasticized peripheral section is disposed between the first peripheral section facing the hip area and the third peripheral section disposed between the legs of the user, and a further non-elasticized fourth peripheral section is provided in the area of a center crotch line. The respective material sections of the second and fourth peripheral section of the hygiene article abut the skin surface of the user with slight pretension. Since the second peripheral section is not subjected to permanently changing gathering or frilling, it does not rub on the surface of the skin. Moreover, air exchange with the inside of the hygiene article is possible, which considerably improves the microclimate in the areas of the skin surface covered by the hygiene article.

An improvement in accordance with the invention is already achieved by providing such a non-elasticized second peripheral section only along the peripheral area of the two leg openings facing the front part. In a further development of this basic inventive idea, the peripheral areas in the front part and also in the rear part are advantageously designed in accordance with the invention such that at least three non-elasticized peripheral sections are provided for each leg opening.

In an advantageous fashion, elasticizing means extending substantially in one transverse direction are provided in the crotch area of the hygiene article. Such an elasticizing means in the area of the absorption body can produce a desired contracting motion of the suction body in the crotch area. The absorption body is advantageously narrow in the crotch area while still providing sufficient absorbing capacity, i.e. absorbent material. The surface density in this area may be increased through contraction in order to provide a large absorption capacity in this area. Moreover, elasticizing means extending in a transverse direction in the crotch area provide the hygiene article with its shape. The crotch area is advantageously cup-shaped.

The elasticizing means extending substantially in the transverse direction in the crotch area or the elasticizing means may be formed separately from those elasticizing means which elasticise the leg openings. In accordance with a further embodiment of the invention, the elasticizing means of the third peripheral section advantageously merge into the elasticizing means of the crotch area, i.e. form the elasticizing means extending in a transverse direction in the crotch area, in that they merge from their extension in the peripheral direction of the leg openings substantially in the transverse direction. They may thereby branch off in a substantially steady or unsteady curve progression, wherein a steady progression is preferred. The fourth non-elasticized peripheral section may be formed by elasticizing means extending from the third peripheral section along a curve to the left, and then traversing the crotch area in a transverse direction. The fourth, non-elasticized peripheral section advantageously covers the center crotch line. The center crotch line extends through the minimum width of the crotch area of the hygiene article. When the minimum cannot be uniquely determined, the center crotch line extends through the center of the crotch area of the hygiene article. The center of the crotch area of a hygiene article can be determined by disposing an elastic thread or rubber band in the shape of a figure eight about the legs of a user standing upright or a user lying prostrate on a flat support, such that the thread or band crosses at one point between the legs. This crossing point is defined as the center of the crotch area of the hygiene article during proper use.

The respective non-elasticized second and/or fourth peripheral sections may just not be provided with elasticizing means. Another feasible and advantageous possibility is that the elasticizing means initially continuously extend in the peripheral direction of the leg openings during production of the inventive hygiene article, and the non-elasticized second and/or fourth peripheral section is/are obtained by cutting through the previously extended elasticizing means. The elasticizing means will then relax or retract unless they are connected, e.g. glued to chassis-forming materials in the second and/or fourth peripheral section. This connection of the elasticizing means should then be limited to the first and third peripheral section which is supposed to be elasticized, so that the cut elasticizing means in the second peripheral section can relax, thereby losing their elasticizing effect on the second peripheral section.

The elasticizing means in the second and/or fourth peripheral section can be separated with one single cut. However, it may be feasible and advantageous to sever the elasticizing means using a plurality of cuts such that the elasticizing means which previously continuously extended in the second and/or fourth peripheral section are divided into a plurality of small sections, in particular, of a length in the millimeter range, thereby losing their elasticizing effect on the second and/or fourth peripheral section. In this case, the elasticizing means may also be connected, e.g. glued, to chassis materials in the second and/or fourth peripheral section without impairing relaxation. The elasticizing means may be easily cut once or several times using laser technology.

In accordance with the invention, the non-elasticized second and/or fourth peripheral section is obtained in that the previously extending elasticizing means loose their elasticizing effect through application of heat and/or pressure and/or laser. This may be achieved, in particular, through irradiation with ultrasound. It is thereby possible to deactivate a previously extending pretensioned elasticizing means by deforming it, in particular, through punctiform or matrix-like application of pressure and/or temperature, in particular, ultrasound, and, in particular, cutting it such that at least its elasticizing effect on the respective peripheral section is eliminated.

Application of heat and/or pressure is more advantageous than cutting in that it reduces the danger of chassis-forming materials being inadvertently cut or perforated. On the other hand, it may be particularly advantageous to cut or perforate the chassis-forming materials in the area of the second and/or fourth peripheral sections, in order to render the hygiene article more breathable at these locations. In particular, when absorption bodies in the form of a functional unit having an absorbent structure and a liquid-impermeable back sheet are used directly below the absorbent structure, the other chassis materials need not be absolutely impermeable to liquids. It may even be desirable to only use air-permeable chassis materials in order to effect breathability. When the above-mentioned functional units are used as an absorption body, chassis materials of non-woven materials or non-woven laminates may advantageously be used. Non-woven laminates with breathable or even liquid-permeable sheets are also feasible. The above-mentioned functional units used as an absorption body may also comprise integrated top sheet layers, and advantageously upright elasticizing collar elements (so-called “cuffs”) which form a lateral outlet barrier. Such collar elements may also be provided outside of the absorption body or the functional unit used as the absorption body.

In accordance with a further inventive idea, a track is advantageously provided which is continuous in the transverse direction for applying heat and/or pressure and also covers the second and/or fourth peripheral section of the respective leg opening. This track, which continuously extends in the transverse direction, may advantageously be produced through continuous, i.e. non-interrupted processing in the machine direction of the materials forming the hygiene article. This is advantageous with regard to production.

Reference is made to EP 1 374 814 A1 which discloses a technology of applying heat and/or pressure for deactivating elasticizing means, the entire disclosure of which is hereby incorporated by reference.

It has turned out to be suitable and advantageous for the first elasticizing peripheral section to extend in the peripheral direction of the leg openings (best viewed in the “flat state” of the sheet materials forming the hygiene article) by 3 to 15 cm, in particular 4 to 15 cm, in particular 5 to 15 cm, and moreover preferentially 5 to 13 cm. The “flat state” thereby means that the hygiene article is disposed or projected onto a support such that its chassis materials are no longer gathered by the elasticizing means. In correspondence with the above-described position of this first peripheral section, the hygiene article, being readily configured and applied to a user, extends from the side from the apex, facing the hip, of the respective leg opening in the clockwise direction or in an anticlockwise direction.

The second non-elasticized peripheral section advantageously extends in the peripheral direction in the flat state by 1 to 10 cm, in particular 2 to 8 cm and preferentially 3 to 8 cm.

The third, likewise elasticized peripheral section advantageously extends in the peripheral direction in the flat state by 1 to 8 cm, in particular 1 to 7 cm, and preferentially 1 to 5 cm.

The fourth non-elasticized peripheral section advantageously extends in the peripheral direction in the flat state by 1 to 7 cm, in particular 1 to 5 cm, and preferentially 1 to 4 cm.

Further features, details and advantages of the invention can be extracted from the enclosed claims and the drawing and the following description of a preferred embodiment of the inventive hygiene article.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a top view of a first embodiment of an inventive hygiene article in the flat state prior to being connected at the longitudinal side edge areas at the manufacturing plant;

FIG. 2 shows a view of a further embodiment of an inventive hygiene article which corresponds to FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a hygiene article, designated in total with reference numeral 2, in the form of a pants-type diaper (“pants”) in the flat state before being connected at the longitudinal side edge sections at the manufacturing plant. The hygiene article comprises a rear part 4, a front part 6, and an intermediate crotch part 10 delimiting the future leg openings 8. In the flat state, the rear part 4 is delimited by longitudinal side edges 12 and the front part 6 is delimited by longitudinal side edges 14. These are connected to each other in the area of the hatched zones 16 and 18 to form the pants shape, i.e. through hot sealing or other conventional joining methods. In this fashion, two side seam areas of the hygiene article are formed which cannot be released without causing damage. The readily configured hygiene article may have a breaking line, e.g. in the form of a release thread, in particular, along these side seam areas so that the hygiene article can be opened in the applied state. Additionally, any closing elements, i.e. adhesive or mechanically connecting closure shackles may be provided so that the hygiene article can be closed again after opening, like a diaper. The hygiene article is produced by the manufacturer in the form of pants having a hip edge 20 which is closed in the peripheral direction and forms a hip opening which is limited on all sides. It is therefore a pants and not a diaper, which can be opened and closed.

The hygiene article 2 also comprises an absorbent body 22 which may also be designed as a functional unit, i.e. may have a liquid absorbing structure with a liquid-impermeable back sheet and optionally further components such as e.g. a top sheet and elasticized collar elements, and be disposed as a functional unit onto chassis-forming materials 24 of the hygiene article 2. These chassis-forming materials 24 may e.g. be any back sheet materials or composite materials. Non-woven materials or non-woven laminates and also non-woven sheet laminates are advantageously used which have a textile-like surface and are preferably also breathable, at least in some areas. The chassis-forming materials 24 may also comprise a top sheet layer facing the body, which covers the absorption body 22 and may extend in a transverse direction 26 and/or in a longitudinal direction 28 of the hygiene article 2 up to the edges thereof.

FIG. 1 also shows elasticizing means 30 which continuously extend in the transverse direction 26 and continuously elasticise a hip edge area 32 of the hygiene article 2. Elasticizing means 36 are moreover indicated by dashed lines in the rear part 4 and in the front part 6 at a separation 34 of 5 to 15 mm from each other, which elasticise only regions of the rear part 4 and front part 6 and provide good fit for the hygiene article 2.

Elasticizing means 38 are moreover shown which elasticise sections of the leg openings 8 as described below:

The elasticizing means 38 extend from the longitudinal side edge 12 of the rear part 4 along a periphery 40 of the respective leg opening 8 in the direction towards a center crotch line 42. The elasticizing effect of the elasticizing means 38 is not continuous to the center crotch line 42 but is limited from the longitudinal side edge 12 to a first peripheral section 44 of the leg openings 8. A second non-elasticized peripheral section 46 of the leg openings is adjacent thereto, to which an elasticized third peripheral section 48 is adjacent. This third peripheral section 49 is joined by a fourth non-elasticized peripheral section, which extends over the center crotch line 42. The periphery 40 of the leg openings 8 is therefore not continuously elasticized. It is not elasticized in the rear part 4 and/or front part 6 in respective second peripheral sections 46 and in a fourth peripheral section 49. This means that the chassis materials 24 in these second and fourth peripheral sections 46 and 49 are not disposed against the skin surface of the user by elastically pretensioning the mostly thread-shaped elasticizing means 38, rather softly abut the skin surface. This improves the breathability, i.e. improves ventilation of the areas outside of the absorption body 22, as is indicated by arrow 50. Moreover, the chassis materials 24 are not gathered or frilled in the second and fourth peripheral sections 46 and 49, which increases the skin friendliness, since skin irritation is reduced.

The second peripheral section 46 of FIG. 1 does not have any elasticizing means 38. This may advantageously be achieved in that the elasticizing means 38 initially continuously extend through all three peripheral sections but are connected, preferably glued, to the chassis materials 24 only in the first and third peripheral section 44, 48 in the pretensioned state. The elasticizing means 38 must be merely cut in the second peripheral section 46, and retract due to their pretension, to their fixture in the first and third peripheral sections 44, 48, such that the second peripheral section 46 is no longer elasticized. The fourth peripheral section 49 is thereby not elasticized, such that the elasticizing means 38 extend from their extension in the third peripheral section 46 along a curve to the inside in the transverse direction 26. The fourth peripheral section 49 is thereby formed between the respective third peripheral section 46 of the rear part 4 and the front part 6.

The elasticizing means 38 in the second peripheral section 46 of the front part 6 are shown with dotted lines on the left hand side of FIG. 1. This represents a further embodiment of the invention, in which the elasticizing means 38, which previously continuously extended from the longitudinal side edge 14 to the center crotch line 42, were cut several times in the second peripheral section 46 at a separation of 1 to 3 mm. In this fashion, the elasticizing means 38 in the second peripheral section 46 are deactivated. Cutting the elasticizing means 38 several times can be achieved by a knife roller in a production machine which rolls over the sheet materials transported in the machine direction in the transverse direction 26. In this case, the previously continuously disposed elasticizing means 38 could also be connected, i.e. glued to the chassis materials 24 in the second peripheral section 46, if this seems to be suitable or is desired for production.

In accordance with a further preferred embodiment of the invention which may also be indicated by the dashed lines in the front part 6 in FIG. 1 on the left hand side, the elasticizing means 38 previously continuously extending from a longitudinal side edge to the center crotch line 42 have lost their elasticizing effect in the second peripheral section 46 through application of heat and/or pressure. The elasticizing means 38 may be deactivated or relaxed through application of heat and/or pressure, i.e. through ultrasound welding methods or through a matrix of heating which results in melting. They are thereby substantially destroyed and can no longer elasticise the second peripheral section 46.

Moreover, elastification extending in the transverse direction 26 is provided in the area of the center crotch line 42. This is advantageously achieved, as mentioned above, in that the above-mentioned elasticizing means 38 “bend” inwards from their extension in the peripheral direction in the third peripheral section 48, i.e. are deflected in the transverse direction 26, and traverse the crotch area 10 in the transverse direction 26 below the absorption body 22, i.e. between the absorption body 22 and the chassis materials 24, to then further extend steadily and continuously into the periphery of the opposite leg opening 8. This guidance of the elasticizing means 38 starting from the third peripheral section 46 is separately claimed and is regarded as an independent invention, i.e. independently of the further features of the claims. Departing from the above-described methods for relaxing the elasticizing means 28 in the second peripheral section 46, it is possible to continuously guide the elasticizing means 38 in the machine direction which corresponds to the transverse direction 26, and to join them to the chassis materials 24 of the hygiene article. This is considered to be particularly advantageous.

Finally, reference is made to the collar elements 52 (“cuffs”) provided on both sides of the absorption body 22, which are elasticized and therefore upright, and which form a lateral barrier for leaking body excretions and also retain liquid body excretions in the area above the absorption body until they have been absorbed by the absorption body 22.

FIG. 2 shows a further embodiment, wherein the elasticizing means 38′ traverse the crotch area but are subsequently deactivated in a conventional fashion, i.e. they are cut or rendered non-elasticizing in a different fashion, in particular through application of heat and/or pressure as mentioned above.

Claims

1. A method for manufacturing a pants-shaped disposable absorbent hygiene article having a longitudinal direction and a transverse direction and a chassis comprising front and rear right edges and front and rear left edges attached to each other, the method comprising the steps of:

a) preparing and transporting flat chassis-forming sheet materials in a transport direction parallel to the transverse direction of the article such that the front and rear right edges lead and the front and rear left edges trail;

b) preparing the chassis in a flat form, the chassis having a front part, a rear part spaced apart from the front part in a longitudinal direction of the article and a crotch part disposed between and contiguous with the front part and the rear part, the crotch part defining a center crotch line extending in the transverse direction of the article, the rear part having a rear right edge and a rear left edge spaced apart from the rear right edge in the transverse direction of the article, the front part having a front right edge and a front left edge spaced apart from the front right edge in the transverse direction;

c) applying a continuous first thread-shaped elastic means to the flat chassis-forming sheet materials, the first elastic means extending from an end of the rear right edge to a first curve location disposed at a separation from but proximate to the center crotch line, the first elastic means curving at the first curve location to proceed in the transverse direction, substantially parallel to the center crotch line, the first elastic means curving away from the center crotch line at a second curve location to travel to an end of the rear left edge;

d) applying a continuous second thread-shaped elastic means to the flat chassis-forming sheet materials, the second elastic means extending from an end of the front right edge to a third curve location at a separation from but proximate to the center crotch line, the second elastic means curving at the third curve location to proceed in the transverse direction, substantially parallel to the center crotch line, the second elastic means curving away from the center crotch line at a fourth curve location to travel up to an end of the front left edge;

e) removing, following step c), an elasticity of a first right and a second left portion of the first elastic means by cutting or through application of heat, pressure and/or laser, the first right portion of the first elastic means disposed proximate the crotch center line between the first curve location and the end of the rear right edge, the second left portion of the first elastic means disposed proximate the crotch center line between the second curve location and the end of the rear left edge;

f) removing, following step d), an elasticity of a third right and a fourth left portion of the second elastic means by cutting or through application of heat, pressure and/or laser, the third right portion of the second elastic means disposed proximate the crotch center line between the third curve location and the end of the front right edge, the fourth left portion of the second elastic means disposed proximate the crotch center line between the fourth curve location and the end of the front left edge;

g) disposing an absorbent body onto the chassis-forming sheet materials;

h) removing material from the chassis-forming sheet materials to define leg openings in the crotch part, the crotch part thereby having a crotch right edge defining a first leg opening for a user, the crotch right edge extending in the longitudinal and transverse directions in a curved, inwardly tapered manner away from the end of the rear right edge outside of, proximate, and substantially parallel to a travel of the first elastic means upstream of the first curve location, the crotch right edge continuing past the first curve location, the center crotch line, and the third curve location to curve outwardly in transverse and longitudinal travel outside of, proximate and substantially parallel to a travel of the second elastic means downstream of the third curve location and terminating at the end of the front right edge, the crotch part having a crotch left edge defining a second leg opening for the user, the crotch left edge extending in the longitudinal and transverse directions in a curved, inwardly tapered manner away from the end of the rear left edge outside of, proximate, and substantially parallel to a travel of the first elastic means upstream of the second curve location, the crotch left edge continuing past the second curve location, the center crotch line, and the fourth curve location to curve outwardly in transverse and longitudinal travel outside of, proximate and substantially parallel to a travel of the second elastic means downstream of the fourth curve location and terminate at the end of the front left edge, wherein the crotch part thereby exhibits a narrowed, tapered transverse width at the center crotch line; and

i) attaching the rear right edge to the front right edge and the rear left edge to the front left edge of the chassis thereby forming the pants-shaped disposable absorbent hygiene article.

2. The method of claim 1, wherein step g) precedes step i).

3. The method of claim 1, wherein at least one of steps e) and f) comprises application of a plurality of cuts to at least one of the first, second, third and fourth portions.

4. The method of claim 1, wherein at least one of the first, second, third and fourth portions have macroscopic ventilation openings in chassis-forming materials thereof.

5. The method of claim 1, wherein the absorbent body comprises a functional unit with an absorbent structure and a liquid-impermeable back sheet which is connected to the chassis.

6. The method of claim 1, wherein the chassis consists essentially of a non-woven material or a non-woven laminate.

7. The method of claim 1, wherein the first elastic means extends between the end of the rear right edge to a beginning of the first portion through a length of 3 to 15 cm, 4 to 15 cm, 5 to 15 cm, or 5 to 13 cm.

8. The method of claim 7, wherein the first portion extends through a length of 1 to 10 cm, 2 to 8 cm, or 3 to 8 cm.

9. A pants-shaped disposable absorbent hygiene article produced by the method of claim 1.