Composite fabric and method for making the same

[0001] The invention relates to a web of composite material with two nonwoven webs located outside and sections of flexible foil film strips arranged between them, the nonwoven webs being connected to each other in the areas between the foil strips.

[0002] A composite material web can be used, for example, to produce elastic fastening straps for baby diapers and for adult diapers, which can also be in the form of flaps and have a correspondingly flexible central area and less flexible end sections adjacent to it on both sides . Inelastic or less flexible end areas are used to attach fastening elements on them, e.g. Velcro straps, and to attach the fastening strap to the bottom of the diaper. To make production inexpensive, a large number of elastics are laminated at a distance with wide nonwoven webs. The fastening strips needed for making diapers are then cut from the resulting composite web.

[0003] A web of composite material with the features described at the outset is known from EP 1 686 209 A1. In this case, the foil strips have a flexible, sticky core, which is covered on one or both sides with a thin nonwoven layer, so that despite the stickiness of the core it is possible to process the foil strips. To guarantee the required flexibility, the webs of composite material are subjected to an annular roll-up process. In the non-woven webs that are stretched and not flexibly retracting to their original state, this creates unevenness that is stretched smoothly during the stretching operation.

film strips from each other between [0004] A simple possibility of producing a web of composite material with the required characteristics is that the two nonwoven webs are joined together through an elastic film. The asymmetrical structure of this type of laminate, however, tends to break in the area usually formed by the adhesive between the foil and nonwoven strips. Furthermore, it is disadvantageous that the elastic film is in this case exposed, and therefore the web of composite material does not have the pleasant textile character of the remaining surface of the diaper in this area.

[0005] The invention is based on the task of proposing a composite material web for the production of diaper fastening elements, especially adult diapers, which can be easily manufactured and at the same time has sufficiently high stability.

[0006] Based on a composite material web with the features described at the outset, this task was solved according to the invention by the fact that the film strips are only connected to the inner surfaces of the nonwoven webs from both the top and bottom side respectively on both longitudinal edges respectively. and that in the areas covering the film strips, the nonwoven webs contain weakness extending towards the web. This weakness may be in the form of perforations or alternatively in the form of crevices or scratches. Thanks to the double-sided connection of the foil belt with the non-woven fabric webs lying outside, a very stable anastomosis is obtained, which easily withstands the loads of the diaper fastening element. If the web of composite material stretches in the transverse direction, the weakening breaks and the elastic film strip is exposed. In this way, the flexibility of the foil belt can be fully exploited.

The first stretching of the diaper fastening element provided with weakness is usually carried out by the person putting on the diaper, in the case of adult diapers, if appropriate, the person wearing the diaper, respectively.

[0007] The nonwoven webs preferably contain one weakening for each foil strip and the weaknesses extend symmetrically to the foil strip. The weaknesses stretch each of the elastomer belts to a layer preferably over the entire length of the foil belts. To create non-flexible sections, the nonwoven webs can be glued together in the areas between the film strips. Preferably, also the edge areas of the film strips are glued to the inner surfaces of the nonwoven webs. Hot melt adhesives can be used in both cases as they form a joint through the lamination operation.

[0008] That, even after exposing the flexible film strip, it may be kept completely the textile nature of the diaper fastening element surface , the foil can be made of a layer and at least one non-woven outer layer applied with elastomer. Since the elastomer layer is often sticky, it may be advantageous to provide it with both layers of nonwoven on both sides. The outer nonwoven layers can have a much smaller thickness than the nonwoven webs to fulfill their intended functions - thus, on the one hand, textile character and, on the other, covering the sticky elastomer layer.

[0009] The invention furthermore relates to a method for producing a web of composite material according to claim 8. Preferred embodiments of this method are described in claims 9 and 10.

[0010] The invention will be explained in detail below based on a drawing showing only an embodiment. They show schematically:

Fig. 1 is a cross-sectional view of the diaper fastening element made of the web of composite material according to the invention, Fig. 2 is a top view of Fig. 1 and Fig. 3 is a method for producing a web of composite material according to the invention.

[0011]

In Fig. 1 a web of composite material is shown, with which individual fastening elements 1 of composite nonwoven diapers 2 can be produced

The web of material comprises two outer webs and sections located between them, film strips 3 of flexible film 4 (see Fig. 3). In the areas 5 between the film strips 3, the nonwoven webs 2 are connected to each other. The foil strips 3 are only connected to the inner surfaces of the nonwoven webs 2 on both respective longitudinal edges 6 both from the top and bottom side. In the areas covering the film strips 3, the nonwoven webs 2 contain weaknesses 7 extending towards the web, which in the embodiment are made in the form of perforations. For each foil strip 3, the nonwoven webs 2 have one perforation 7 each, which again runs symmetrically relative to the foil strip 3. 7 extend along the entire length of the strips In areas 5 between the film strips 3 respectively Film perforations 3 nonwoven webs 2 are glued together over the entire surface, while the edge areas of the film strips are glued over the entire surface with the internal surfaces of the nonwoven webs 2. Bonding can occur on an example of laminating operations using hot melt glue 8. In fig. 1 it can further be seen that each foil strip 3 consists of an elastomeric layer 9 and at least one nonwoven outer layer 10 applied to the elastomeric layer 9. In the embodiment, the elastomer layer 9 is sticky and is therefore provided with thin outer layers 10 of nonwoven on both sides. These outer layers 10 preferably have a surface weight of between 5 g / m2² g / m², while the nonwoven webs 2 have a correspondingly significantly higher surface weight.

[0012] The method of stretched nonwoven with each other Through

In Fig. 3, a web of composite material according to the invention is shown. By cutting operation from the flexible film 4, first, the film strips 3 are produced, which are guided over the devices 11 to change direction and as strips in parallel spaced from each other are fed to the laminating device 12, in which the film strips 3 are placed and laminated between ribbon

2. By applying the adhesive to the entire surface of the nonwoven webs 2 are joined in areas 5 between the film strips 3. Appropriate application of the adhesive on the inner surface of both webs 2 of composite material The film strips 3 are only on both respective longitudinal edges 6 connected to the internal surfaces of the nonwoven webs 2 , both from the top and bottom. Both the combination of both nonwoven webs 2 and the connection of the 3 nonwoven film strips 2 occurs in

Previously, the nonwoven webs 2 are perforated towards the web in the areas covering the film strip 3, symmetrically to the corresponding film strip 3. To this end, the nonwoven webs 2 pass through a suitable perforating device 13. The resulting composite material web can be further processed as a result of the respective cutting operations for elastic fasteners 1 for diapers, each containing only one foil strap

3.

laminating device with both ribbons.

[0013] The interconnected nonwoven webs 2 form in the areas 5 between the film strips 3 inelastic areas, while the sections containing one film strip 3 each form an exposed elastic area. The nonwoven webs 2 and the outer layers 10 of the film strips 3 are preferably made of the same raw materials, e.g. polypropylene fibers. In terms of fiber structure, the outer layers 10 of the film strips 3 may differ from the nonwoven webs 2. Preferably, the dense fiber structure is chosen for the outer layers 10 of the film strips 3, which prevents the rolled layers from sticking together. However, the relatively thin outer layer thickness is sufficient to guarantee the required textile surface. On the other hand, the non-woven layers 2 laminated from the outside preferably have a loose, fluffy fiber structure to create a pleasant textile surface structure, but are clearly thicker than the outer layers 10.

Mondi Consumer Packaging Technologies GmbH

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