METHOD FOR PRODUCING A NONWOVEN ELEMENT FOR HYGIENE ARTICLES

Abstract

A method for producing a nonwoven element for hygiene articles is accomplished by the steps of: forming a fibrous web from a multi-ply nonwoven material with at least one carded staple fiber layer and a storage layer which is arranged on the staple fiber layer and which has cellulose fibers, wherein at least a portion of the staple fibers of the staple fiber layer are formed from a thermoplastic; applying liquid jets to the fibrous web, as a result of which the fibers of the multi-ply nonwoven material are intermingled and entangled, and the fibrous web is embossed with a surface structure; applying heat to the fibrous web, as a result of which the thermoplastic staple fibers at least partially fuse and the fibrous web is bonded to form a nonwoven web, and severing individual nonwoven elements from the nonwoven web.

Claims

1. A method for producing a nonwoven element for hygiene articles, comprising at least the following steps: forming a fibrous web from a multi-ply nonwoven material with at least one carded staple fiber layer and a storage layer which is arranged on the staple fiber layer and which has cellulose fibers, wherein at least a portion of the staple fibers of the staple fiber layer are formed from a thermoplastic material, applying liquid jets to the fibrous web, as a result of which the fibers of the multi-ply nonwoven material are intermingled and entangled, and the fibrous web is embossed with a surface structure, and applying heat to the fibrous web, as a result of which the thermoplastic staple fibers at least partially fuse and the fibrous web is bonded to form a nonwoven web.

2. The method according to claim 1, wherein the storage layer additionally has staple fibers comprising a thermoplastic material.

3. The method according to claim 1, wherein the multi-ply nonwoven material has a further fiber layer, wherein the storage layer is arranged between the staple fiber layer and the further fiber layer, wherein the further fiber layer is formed at least partially from thermoplastic staple fibers.

4. The method according to claim 3, wherein the further fiber layer is formed as carded staple fiber layer or as spunbonded layer comprising continuous filaments.

5. The method according to claim 1, wherein the thermoplastic staple fibers in the at least one staple fiber layer are each formed at least partially from a thermoplastic material or as bicomponent fibers with a core and a cladding of a thermoplastic material.

6. The method according to claim 1, wherein the proportion of thermoplastic staple fibers in the at least one staple fiber layer is at least 20 wt%.

7. The method according to claim 5, wherein the thermoplastic staple fibers in the at least one staple fiber layer are formed with the core and the cladding of thermoplastic material and wherein the core is formed from a material which has a change in length of less than 10% at a temperature of 170° C.

8. The method according to claim 2, wherein the thermoplastic material of the thermoplastic staple fibers in the at least one staple fiber layer and/or in the storage layer has a melting temperature of less than 170° C.

9. The method according to claim 2, wherein the thermoplastic material of the thermoplastic staple fibers in the at least one staple fiber layer and/or in the storage layer is a polyolefin, selected from the group consisting of polyethylene and polypropylene.

10. The method according to claim 2, wherein the thermoplastic staple fibers of the at least one staple fiber layer and in the storage layer have the same thermoplastic material.

11. The method according to claim 1, wherein a portion of the staple fibers in the at least one staple fiber layer is formed from a non-thermoplastic material.

12. The method according to claim 11, wherein the staple fibers formed from a non-thermoplastic material are natural fibers, selected from the group consisting of cotton, wool, linen, hemp, flax and cellulose.

13. The method according to claim 1, wherein the nonwoven web is thermally smoothed on one side.

14. The method according to claim 1, wherein the nonwoven web has a basis weight of between 45 and 150 g/m.sup.2.

15. The method according to claim 1, wherein the cellulose fibers have a length of between 4 and 10 mm.

16. A nonwoven element for hygiene articles, obtainable by means of a method according to claim 1, comprising a multi-ply nonwoven material which is embossed with a surface structure, at least one carded staple fiber layer, and a storage layer which is arranged on the staple fiber layer and is formed of staple fibers and cellulose fibers, wherein the fibers of the nonwoven material are entangled with one another and the staple fibers are at least partially bonded to one another.

17. The nonwoven element according to claim 16, wherein the storage layer is arranged between two fiber layers.

18. The nonwoven element according to claim 17, wherein the two fiber layers are formed as carded staple fiber layers, or wherein one of the fiber layers is formed as spunbonded layer of continuous filaments.

19. The nonwoven element according to claim 16, wherein the nonwoven element has a basis weight of between 40 and 150 g/m.sup.2.

20. A hygiene article formed of the nonwoven element according to claim 16.

21. The hygiene article according to claim 20, wherein the nonwoven element is saturated at least partially with a cleaning liquid.

22. The hygiene article according to claim 20, wherein connection elements are provided for mechanical fastening to a cleaning unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The invention will be described in more detail in the following referring to the initial example. In the drawings:

[0043] FIGS. 1 and 2 show methods according to the invention for producing a nonwoven element;

[0044] FIG. 3 shows a nonwoven element produced by the method according to FIG. 1;

[0045] FIG. 4 shows a nonwoven element produced by the method according to FIG. 2; and

[0046] FIG. 5 shows the nonwoven element according to FIG. 3.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] FIG. 1 shows a method according to the invention, a first fiber layer 2 being formed as spun fiber layer by means of a spun fiber extruder 1. Accordingly, the first fiber layer 2 has a multiplicity of continuous filaments 20. The continuous filaments 20 are formed from polypropylene. The spun fiber layer is formed generally with a basis weight of between 10 and 18 g/m.sup.2.

[0048] In a further process step, storage layer 3 comprising staple fibers 4 and cellulose fibers 5 is laid on the first fiber layer 2. This is carried out in a so-called air-laid process with an air-laid machine 6 which loosely lays the staple fibers 4 and the cellulose fibers 5 of the storage layer 3 on the first fiber layer 2.

[0049] There follows the arrangement of a second fiber layer 7 which is formed as a carded staple fiber layer with a multiplicity of staple fibers and which is arranged in such a way that the storage layer 3 is arranged between the first fiber layer 2 and the second fiber layer 7. In this connection, the individual staple fibers of the second fiber layer 7 are aligned via a carding machine 8 and supplied as a cohesive fiber layer 7.

[0050] Accordingly, a multi-ply nonwoven material is formed from two fiber layers 2, 7 and a storage layer 3 which is arranged between the fiber layers 2, 7. At least the second fiber layer 7, as staple fiber layer, and also the storage layer has thermoplastic staple fibers 4 which are correspondingly formed at least partially from a thermoplastic material.

[0051] In a subsequent process step, the fibrous web 9 constructed in this way from a multi-ply nonwoven material is acted upon by liquid jets in an apparatus 10 in such a way that the fibers 10 of the fibrous web 9 are intermingled and entangled. At the same time, the fibrous web 9 is embossed with a surface structure. The layers of multi-ply nonwoven material which initially lie on one another relatively loosely are interconnected by mechanically entangling the fibers and the fibrous web 9 is accordingly consolidated.

[0052] In a subsequent step, the nonwoven material of the fibrous web 9 which is consolidated in this way can be fed to an oven 11 so that the fibrous web 9 is acted upon by hot air or by heat. In this respect, it is essential that the continuous filaments of the first fiber layer 2 and the thermoplastic staple fibers 4 of the second fiber layer 7 and of the storage layer 3 are at least partially formed from a thermoplastic material. Under the influence of heat, the fibers fuse and bond to one another. In this way, the storage layer 3 in particular is stabilized between the first fiber layer 2 and the second fiber layer 7, and the multi-ply structure of the fibrous web 9 is secured. The oven 11 is operated for this purpose at a temperature of at least 170° C., the temperature being governed by the melting temperature of the different fiber materials.

[0053] FIG. 2 shows an alternative method in which a further, second carding machine 12 which forms the first fiber layer 2 as well as the staple fiber layer is provided instead of a spun fiber extruder 1. The further process steps correspond to those in FIG. 1.

[0054] Accordingly, the nonwoven webs 9 differ in that exclusively staple fiber layers are provided according to FIG. 2, while a fiber layer is formed as spun fiber layer according to FIG. 1.

[0055] FIG. 3 shows a nonwoven element 13 which was formed with a method according to FIG. 1 by cutting out from the nonwoven web 9. The individual bonding steps are shown neither in FIG. 3 nor in FIG. 4. The nonwoven element 13 is accordingly distinguished by a three-ply construction with spun fiber layer 14 and a staple fiber layer 15 which is formed from carded staple fibers. A storage layer 16 which is formed from thermoplastic staple fibers 4 and cellulose fibers 5 is arranged between the staple fiber layer 15 and spun fiber layer 14. According to FIG. 4, two staple fiber layers 15, 17 are provided proceeding from the staple fiber layers according to FIG. 2. In both cases, thermoplastic staple fibers 4 which are formed as bicomponent fibers with a core of a non-thermoplastic material and a cladding formed from a thermoplastic material are provided in the staple fiber layers 15, 17. However, it is sufficient in principle when only one of the spun fiber layers 15, 17 has thermoplastic staple fibers 4. The continuous filaments 20 and the spun fiber layer 14 are also formed from a thermoplastic material.

[0056] FIG. 5 shows a nonwoven element 13 according to the invention corresponding to FIG. 3 in which a surface structure in the form of indentations 18 is now visible in addition. Further, the individual fibers were also interconnected by means of liquid jets.

[0057] Further, it is provided according to the invention that the storage layer 16 is formed at least partially from non-thermoplastic staple fibers 19, particularly from natural fibers. These natural fibers can be cotton, wool, linen, hemp, flax or the like, for example.

Example 1

[0058] In connection with a first embodiment example, a nonwoven element 13 was formed with an outer spun fiber layer 14 of polypropylene and with a basis weight of 12 g/m.sup.2. The storage layer 16 has a basis weight of 28 g/m.sup.2 and is enclosed by a staple fiber layer 15 of carded thermoplastic staple fibers 4 having a core of polyethylene terephthalate and a cladding of polyethylene. The staple fibers have a fineness of 1.7 dtex. The basis weight of the staple fiber layer 15 amounts to 20 g/m.sup.2. The nonwoven element further has an embossed surface structure in the form of punctiform depressions.

Example 2

[0059] According to a further embodiment example, a nonwoven element 13 was formed with an outer spun fiber layer 14 of polypropylene and a basis weight of 15 g/m.sup.2. The storage layer 16 is made from Lyocell staple fibers and has a basis weight of 50 g/m.sup.2. Lyocell staple fibers are regenerated fibers of cellulose. The storage layer 16 is enclosed by a staple fiber layer 15 of carded thermoplastic staple fibers 4 with a core of polyethylene terephthalate and a cladding of polyethylene. The staple fibers have a fineness of 3.4 dtex. The basis weight of the staple fiber layer 15 amounts to 50 g/m.sup.2. Further, the nonwoven element 13 has an embossed surface structure in the form of punctiform depressions.

Example 3

[0060] According to a third embodiment example, two staple fiber layers 15, 17 are provided. The one staple fiber layer 15 is formed from staple fibers 4 of polyethylene terephthalate. The staple fibers have a fineness of 1.7 dtex. The basis weight of the staple fiber layer 15 amounts to 15 g/m.sup.2. The storage layer 16 corresponds to that of Example 1 with a basis weight of 30 g/m.sup.2. The second staple fiber layer 17 is formed of thermoplastic staple fibers 4 having a core of polyethylene terephthalate and a cladding of polyethylene. The fineness is 2.2 dtex, and the basis weight is 15 g/m.sup.2.

Example 4

[0061] According to a fourth embodiment example, two staple fiber layers 15, 17 are provided. The one staple fiber layer 15 is formed from thermoplastic staple fibers 4 having a core of a first polylactide and a cladding comprising a second polylactide, the melting temperature of the first polylactide being 30 K higher than that of the second polylactide. The staple fibers have a fineness of 3.4 dtex. The basis weight of the staple fiber layer 15 amounts to 25 g/m.sup.2. The further staple fiber layer 17 is formed almost identically, but the fineness is only 1.7 dtex. The storage layer 16 corresponds to that of Example 1 but has a basis weight of 50 g/m.sup.2.

Example 5

[0062] According to a fifth embodiment example, two staple fiber layers 15, 17 are provided. The first staple fiber layer 15 and the second staple fiber layer 17 are formed with 50% thermoplastic staple fibers 4 having a core of polyethylene terephthalate and a cladding of polyethylene and 50% thermoplastic staple fibers 4 of polyethylene terephthalate. The fineness amounts to 1.7 dtex and the basis weight amounts to 20 g/m.sup.2. The storage layer 16 corresponds to that of Example 1 but with a basis weight of 30 g/m.sup.2.

Example 6

[0063] According to a sixth embodiment example, two staple fiber layers 15, 17 are provided. The first staple fiber layer 15 is formed from staple fibers of viscose with a fineness of 1.7 dtex, and the second staple fiber layer 17 is formed from staple fibers with a core of polyethylene terephthalate and a cladding of polyethylene with a fineness of 3.4 dtex. Viscose is a regenerated cellulose. The basis weight amounts to 15 g/m.sup.2 for the first staple fiber layer 15 and 20 g/m.sup.2 for the second staple fiber layer 17. The storage layer 16 corresponds to that of Example 1 but with a basis weight of 30 g/m.sup.2.

Example 7

[0064] According to a seventh embodiment example, two staple fiber layers 15, 17 are formed of staple fibers of viscose with a fineness of 1.7 dtex. The basis weight amounts to 20 g/m.sup.2. The storage layer 16 is formed from a mixture of Tyvek fibers (HDPE) and cellulose flakes with a basis weight of 40 g/m.sup.2.

[0065] In all of the examples mentioned above, the second staple fiber layer 17 or the spun fiber layer 14 forms one side of a nonwoven element 13 which forms a cleaning side of a hygiene article, e.g., of a cleaning wipe. To this end, the fibers utilized in these layers can have a greater thickness than the staple fibers of the staple fiber layer 15. As a result of the thicker fibers, the abrasive effect is increased in the course of cleaning. Different hygiene products which have been formed from the above-mentioned nonwoven elements 13, for example, are discussed in the following.

[0066] Various hygiene products can be produced from the above-mentioned nonwoven elements 13. Various exemplary sanitary wipes are discussed in the following.

Example 8

[0067] Sanitary wipes for wet cleaning with an equal proportion of hydrophilic fibers and lipophilic fibers in order to be able to sufficiently absorb cleaning liquid on the one hand and removed fats and dirt on the other hand. Further, the sanitary wipe has areas with high hardness. This can be achieved, for example, by means of hot embossing. Beyond this, the sanitary wipe can also have connection elements for mechanical fastening to a cleaning unit.

Example 9

[0068] The sanitary wipe from Example 8 which is formed, however, for dry cleaning and is accordingly not saturated with a cleaning liquid. In this way, liquids can be absorbed particularly well in the course of cleaning.

Example 10

[0069] A sanitary wipe with different sides, a first side being formed chiefly by hydrophilic fibers, and the second side constitutes the actual cleaning side. The nonwoven element 13 contacts a cleaning liquid reservoir via the first side. The cleaning liquid reservoir makes it possible to transport cleaning liquid to the second side by exerting pressure via the first side. The cleaning side is also formed with areas of high hardness in this instance. These areas increase the efficiency and the effectiveness of cleaning, while the first side allows capillary transport of cleaning liquid.

[0070] In this case also, the sanitary wipe can have connection elements for mechanically fastening to a cleaning unit.