ELASTIC DIAPER ELEMENT

Abstract

An elastic diaper element that includes an elastic layer (1) and at least one layer (2) made of a nonwoven. The elastic element has connection regions (5) between the elastic layer (1) and the non-woven layer (2). The connection regions (5) extend in a preferred direction. The non-woven layer (2) is wavy when the diaper element is in the unstretched condition in order to provide regions (6) as a reserve allowing stretching. The connection regions (5) have an oscillating shape along their extent.

Claims

1. An elastic diaper element, comprising: an elastic layer (1); a layer (2) of a nonwoven; connection regions (5) between the elastic layer (1) and the layer (2) of the non-woven, the connection regions (5) have an extent in a preferred direction, wherein the layer (2) of the non-woven in an unstretched state of the diaper element is wavy and provides regions (6) as a reserve for enabling stretching; and the connection regions (5) in an extent thereof have an oscillating profile.

2. The diaper element as claimed in claim 1, wherein the connection regions (5) have a wavy profile.

3. The diaper element as claimed in claim 1, wherein or the connection regions (5) have a zigzag profile.

4. The diaper element as claimed in claim 1, wherein the extent of the connection regions (5) runs perpendicularly to as tensile direction of the diaper element.

5. The diaper element as claimed in claim 1, wherein a first phase of the oscillating profile has a length (12) of more than 10 mm and less than 200 mm.

6. The diaper element as claimed in claim 1, wherein a first phase of the oscillating profile has an amplitude (11) of more than 0.5 mm and less than 10 mm.

7. The diaper element as claimed in claim 1, wherein the layer (2) of the non-woven comprises a hydroentangled non-woven material, and the non-woven material has a specific weight of 10 to 70 g/m.sup.2.

8. The diaper element as claimed in claim 1, wherein the elastic layer (1) is constructed in multiple layers and includes one core layer (3) and at least one further layer (4).

9. The diaper element as claimed in claim 1, further comprising a second layer of a non-woven, wherein the elastic layer (1) is disposed between the layer of the non-woven and the second layer of the non-woven.

10. A method for producing an elastic laminate having an elastic layer (1) and a layer (2) of a non-woven, the method comprising: generating connection regions (5) between the elastic layer (1) and the layer (2) of the non-woven, with the connection regions (5) having an extent in a preferred direction, and the layer (2) from the non-woven, in a non-stretched state of the diaper element being formed as wavy providing regions (6) as a reserve for enabling stretching; and the connection regions (5) are generated in a profile that oscillates in the extent of said connection regions (5).

11. The method as claimed in claim 10, further comprising generating the connection regions (5) using rollers which have flutes that run in an oscillating manner.

12. The method as claimed in claim 10, wherein the connection regions (5) are generated using mutually engaging oscillating rollers.

13. The method as claimed in claim 10, further comprising incorporating the elastic laminate in a diaper as an elastic diaper element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Further advantages and features of the invention are derived from the description of an exemplary embodiment by means of drawings, and from the drawings per se.

[0062] In the drawings:

[0063] FIG. 1 shows a section through a diaper element according to the invention;

[0064] FIG. 2 shows a schematic plan view of the diaper element, having a first variant of the wavy connection regions;

[0065] FIG. 3 shows a schematic plan view of the diaper element, having a second variant of the wavy connection regions;

[0066] FIG. 4 shows a schematic plan view of a connection region extending in a wave-shaped manner, highlighting the continuously varying angle between the connection region and the tensile direction;

[0067] FIG. 5 shows a schematic plan view of the diaper element, having a further variant of the wavy connection regions; and

[0068] FIG. 6 shows a schematic plan view of the diaper element, having an alternative variant of the wavy connection regions.

DETAILED DESCRIPTION

[0069] According to FIG. 1, the laminate comprises an elastic layer 1 and a non-woven layer 2 from a wavy non-woven material. This here is a hydroentangled non-woven material, wherein a spunbonded non-woven material from continuous filaments is used in the exemplary embodiment. According to the invention, the non-woven material is brought to a wavy shape prior to being connected to the elastic layer 1. Upon extruding the elastic layer 1 so as to form the wavy non-woven layer 2, the depressions of the non-woven material are impressed in the fusible elastic layer 1 such that connection regions 5 between the wavy non-woven material 2 and the elastic layer 1 are configured.

[0070] The elastic layer 1 in the exemplary embodiment is embodied as a multi-layered co-extruded film, having a core layer 3 and a further layer 4 which is configured as a skin layer. The ratio of the thickness of the core layer 3 and the further layer 4 is preferably more than 8:1, in particular more than 10:1, in particular more than 12:1. The skin layer 4 preferably has a weight between 1 and 3 g/m.sup.2.

[0071] The core layer 3 is preferably composed of thermoplastic polymers. Polypropylene-polyethylene block copolymers are preferably used here, for example of the type Exxon Vistamaxx (PP based); VM 6102 or VM 6202 or VM 7810, and/or of the type Dow Infuse (PE based): Infuse 9507, Infuse 9107.

[0072] The external layer 4 is preferably composed of a polyolefin or an ethylene vinyl acetate copolymer (EVA). As opposed to the core layer 3, the external layer 4 is not sticky and thus prevents undesirable adhesion.

[0073] According to the invention, the laminate comprises connection regions 5 and reserve regions 6. The reserve regions 6 have no, or only a very weak, bond with the elastic layer 1 and preferably enclose cavities 7.

[0074] In the exemplary embodiment, the web-to-groove ratio of the roller which brings the non-woven into a wavy shape and impresses the depressions of the wavy non-woven layer 2 into the fusible elastic layer 1 is 1:6, wherein the web width is preferably 0.5 mm, and the groove width is preferably 3 mm.

[0075] The connection regions 5 according to the invention in the exemplary embodiment have different zones 8, 9.

[0076] The outer zone 9 is free of elastic material so that the elastic material does not penetrate the non-woven layer 2. The non-woven material in the outer zone 8 is not thermally influenced from the outside so that the filaments of the layer 2 from a non-woven are not fused.

[0077] A form-fitting composite of solidified elastic material and non-woven material is present in the inner zone 8 of the connection regions 5. In the exemplary embodiment here, the non-woven material is also not fused in the inner zone 8. The continuous filaments of the hydroentangled non-woven material are merely impressed into the elastic melt such that a form-fitting composite is created upon solidification. The continuous filaments of the hydroentangled non-woven material per se remain largely influenced in the connection process. These continuous filaments are merely enclosed by the fusible material of the elastic layer 1.

[0078] Upon solidification of the elastic material, there is a form-fitting composite of non-woven material and solidified material of the elastic layer 1 present in the inner zone 8.

[0079] The laminate illustrated in the figure is interconnected between a pair of rollers in which, when viewed in the drawing, a profiled roller having elevations presses the non-woven layer 2 from above into the elastic layer 1, and a counter-roller having a small surface is disposed therebelow. In the production of the laminate illustrated in FIG. 1, a cooling roller is used as the counter-roller. The cooling roller is a steel roller. The roller acting from above is a roller that is not cooled.

[0080] The rollers used for connecting are operated at a spacing, wherein a fixed spacing is set.

[0081] The laminate preferably has a specific area weight of more than 10 g/m.sup.2, in particular more than 20 g/m2, preferably more than 30 g/m.sup.2, and/or less than 200 g/m.sup.2, in particular less than 150 g/m.sup.2, preferably less than 100 g/m.sup.2.

[0082] In the exemplary embodiment, the connection regions 5 and the reserve regions 6 are embodied in the shape of strips, wherein the strips run transversely to the tensile direction of the diaper element.

[0083] The strips of the connection regions 5 have a width between 0.1 and 1 mm. The connection regions 5 in the exemplary embodiments have a width of 0.5 mm.

[0084] The strips of the reserve regions 6 that do not have a connection between the non-woven layer 2 and the elastic layer 1 have a width between 2 and 6 mm. The reserve regions 6 in the exemplary embodiment have a width of 3 mm. In this way, the connection regions 5 in the exemplary embodiment have a proportion of 0.5/3.5=14.3%, and the reserve regions 6 have a proportion of 3/3.5=85.7% in terms of the surface of the flat, unstretched elastic layer 1.

[0085] FIG. 2 shows a schematic plan view of the diaper element, having a first variant of the wavy connection regions 5. The connection regions 5 extend transversely to the tensile direction. The connection regions 5 are embodied as continuous wavy lines, wherein the spacing 10 of these lines in the exemplary embodiment is approx. 3 mm.

[0086] The imaginary auxiliary line 13 of the wavy profile of the connection regions 5 marks the deflection of the wave as the amplitude 11 in relation to the imaginary auxiliary line 13. In the regular repeating shape of the wavy profile of the connection regions 5, the length of the phase 12 marks the smallest local interval. The length of one phase 12 of the wavy line extends in the range of 30 to 100 mm. The amplitude 11 has a dimension between 1 to 6 mm. The ratio between the amplitude 11 and the phase 12 is more than 0.001, preferably more than 0.005, in particular more than 0.01, and/or less than 0.6, preferably less than 0.4, in particular less than 0.2.

[0087] The block arrows which, when viewed in the drawing, point upward and downward show the tensile direction of the diaper element under stress. The imaginary auxiliary line 13 corresponds to the direction of extent of the connection regions 5.

[0088] FIG. 3 shows a schematic plan view of the diaper element, having a second variant of the wavy connection regions 5. Those connection regions 5 extend along the imaginary auxiliary line 13 and thus transversely to the tensile direction of the diaper element under stress, the latter being indicated by block arrows which, when viewed in the drawing, point upward and downward.

[0089] Two connection regions 5 here are in each case mutually aligned so as to be mirror symmetrical. The spacing 14 of the imaginary auxiliary line 13 is at least double the amplitude 11 plus the minimum spacing 15, the latter being at least 1 mm. This results in a maximum spacing 16 of the connection regions 5 that corresponds to four times the amplitude 11 plus the minimum spacing 15.

[0090] Reserve regions 6 (not illustrated in the figure) in which the wavy non-woven layer by way of the elevations thereof protrudes in pleats from the central layer and encloses cavities 7 are disposed between the connection regions 5. These regions 6 serve as a reserve for stretching of the diaper element. By virtue of the connection regions 5 that extend in a wave-shaped manner, the reserve regions 6 have at their disposal different reserves of the non-woven layer and thus different reserves in terms of elongation capability, said reserves complementing one another in a mirror-symmetrical manner.

[0091] FIG. 4 schematically shows a wavy profile of a connection region 5 which extends about the imaginary auxiliary line 13 in a wave-shaped manner. The block arrows which, when viewing the drawing, point upward and downward indicate the tensile direction of the diaper element under stress.

[0092] This results in an angle between the gradient tangent of the connection region 5 and the direction of the tensile stress that continually varies in the wavy profile. In the plan view here, the angle at the wave peak 18 as well as the angle at the wave trough 20 are exactly 90°. Proceeding from an angle at the wave trough (comparable to 20) toward the angle at the wave peak 18, this angle continually increases, reaches a maximum angle 17 of 135° at the reversal point, and then continually decreases toward the angle at the wave peak 18. In the further profile of the connection region 5, the angle between the gradient tangent and the direction of the tensile stress further decreases until said angle reaches a minimum angle of 45° at the reversal point 19, from there continually increasing.

[0093] FIG. 5 shows a schematic plan view of the diaper element in a further variant of the invention in terms of the connection regions 5 that extend about the imaginary auxiliary line 13 in a wave-shaped manner. The connection regions 5 disposed next to one another may differ in terms of the amplitude 11 and 22 thereof, as well as in terms of the wavelength 12 and 21 thereof. Reserve regions 6 which provide different reserves of the non-woven layer for stretching are thus created. When viewed in detail, reserve regions 6 which appear to be random and, when viewed on a larger area, result in an orderly pattern of reserve regions that is regularly repeated, are formed.

[0094] FIG. 6 shows a schematic plan view of the diaper element, having an alternative variant of the wavy connection regions 5. Those connection regions 5 extend along the imaginary auxiliary line 13 and thus transversely to the tensile direction of the diaper element under stress, this being indicated by the block arrows which, when viewed in the drawing, point upward and downward.

[0095] Connection regions 5 which are disposed next to one another here are identical in terms of the amplitude 11 and the wavelength 12 thereof, but are offset in terms of the phases thereof. This phase shift 23, in the case of connection regions 5 that are next to one another, can be implemented in the range from 0 to 2. In the case of connection regions 5 that are not disposed directly next to one another, the phase shifts 25 and 26 can be in the range from 0 to 2n.

[0096] This has the consequence that the imaginary auxiliary lines 13 may have different spacings 22 and 24 which result when the connection regions 5 do not intersect and at the same time are disposed as densely as possible. Reserve regions 6 which provide different reserves of the non-woven layer for stretching are created from this observation. In terms of a small region of this schematic plan view, reserve regions 6 which appear to be random are formed, said reserve regions 6 when viewed on a larger area resulting in an orderly pattern of reserve regions that is regularly repeated.