METHOD AND APPARATUS FOR MAKING A NONWOVEN TEXTILE

Abstract

The invention relates to a method for producing a nonwoven fabric comprising at least one nonwoven web composed of fibres. The fibres are produced by means of at least one fibre-producing device. Subsequently, the fibres are deposited on at least one depositing device in order to form the nonwoven web. The nonwoven web or nonwoven fabric is solidified with at least one calender roller, and the nonwoven fabric is also solidified or primarily solidified with at least one hot fluid primary solidification device.

Claims

1. A method of making a nonwoven fabric comprising a nonwoven web of filaments, wherein filaments are made with at least one filament-making device, the filaments are subsequently deposited on a receiving device to form the nonwoven web, the nonwoven web or the nonwoven fabric is consolidated with a calender roller, and the nonwoven fabric is additionally consolidated or main consolidated with a t least one hot-fluid main consolidater.

2. The method according to claim 1, wherein the nonwoven fabric is detached from the receiving device prior to the consolidation with the calender roller and/or prior to the main consolidation with the hot-fluid main consolidater.

3. The method according to claim 1, wherein the consolidation of the nonwoven fabric with the calender roller is carried out before or after consolidation or main consolidation of the nonwoven fabric with the hot-fluid main consolidater.

4. The method according to claim 1, wherein the nonwoven fabric after being deposited on the receiving device and before consolidation or main consolidation is initially preconsolidated with a preconsolidater.

5. The method according to claim 1, wherein the hot-fluid main consolidater is a hot-air oven, an omega oven, a multidrum oven, a single belt oven, or a double belt oven.

6. The method according to claim 1, wherein the residence time of the nonwoven fabric in the hot-fluid main consolidater is 0.4 s to 25 s or the fluid velocity of the fluid of the hot-fluid main consolidater is 0.4 to 3 m/s.

7. The method according to claim 1, wherein a surface temperature of the calender roller is higher than the fluid temperature T2 of the hot-fluid main consolidater, is lower than the fluid temperature of the hot-fluid main consolidater, or is identical or substantially identical to the fluid temperature of the hot-fluid main consolidater.

8. The method according to claim 1, wherein the filaments of the nonwoven web are made or spun as continuous multicomponent filaments.

9. The method according to claim 8, wherein the multicomponent filaments comprise a first component that consists or substantially consists of a polyolefin or the multicomponent filaments comprise a second or further component that consists or substantially consists of a thermoplastic material.

10. The method according to claim 8, wherein the continuous filaments are made or spun as multicomponent or bicomponent filaments with side-by-side configuration or with core-sheath configuration.

11. The method according to claim 9, wherein a surface temperature T1 of the calender roller or the fluid temperature T2 of the hot-fluid main consolidater in relation to a melting temperature Tm of the first component of the multicomponent filaments or bicomponent filaments satisfies the following condition: (Tm15 C.)<T1 and/or T2<(Tm+15 C.).

12. The method according to claim 1, wherein an embossing pattern comprising a plurality of embossments is introduced into the nonwoven fabric by the calender roller, the embossments each having an embossing area of 0.05 to 0.6 mm.sup.2.

13. The method according to claim 12, wherein the embossing pattern is made such that a smallest spacing d between two adjacent embossments of each of the embossing pattern is 0.6 to 3.0 mm.

14. The method according to claim 12, wherein the embossing pattern is made such that a proportion of the total embossing area of the embossing pattern to a total surface area of the nonwoven fabric is 2 to 15%.

15. The method according to claim 1, wherein a nonwoven fabric with at least two nonwoven webs is made from first filaments made by a first filament-making device, and are then deposited on a receiving device, to form the nonwoven web, second filaments are made by a second filament-making device and are then deposited on the first nonwoven web to form a laminate with the second nonwoven web, the laminate composed of the at least two nonwoven webs is consolidated with a calender roller, and the laminate is additionally consolidated or main consolidated with a hot-fluid main consolidater.

16. An apparatus for making a nonwoven fabric comprising a nonwoven web of filaments, the apparatus comprising: a filament-making device, a receiving device for deposition of the filaments to form the nonwoven web, a calender roller for consolidating the nonwoven web, and a hot-fluid main consolidater for main consolidation of the nonwoven web.

17. The apparatus according to claim 16, wherein the calender roller is provided in the travel direction of the nonwoven fabric upstream or downstream of the hot-fluid main consolidater.

18. The apparatus according to claim 16, wherein the calender roller has a complementary embossing pattern of embossing elements for introducing an embossing pattern of a plurality of embossments into the nonwoven fabric, the embossing elements each having a pressing area of 0.05 to 0.6 mm.sup.2.

19. A nonwoven fabric made by a process according to claim 1.

20. The nonwoven fabric according to claim 19, wherein the nonwoven fabric has an embossing pattern of a plurality of embossments that each have an embossing area of 0.05 to 0.6 mm.sup.2 or the embossing areas of the embossments in plan view have a geometry selected from the group: punctuate or circular, elliptical, square, rectangular, diamond-shaped, polygonal, linear, wavy.

21. The nonwoven fabric according to claim 20, wherein the nonwoven fabric has a mass per unit area of less than 200 g/m.sup.2 or the nonwoven fabric has a thickness h of 0.1 to 1.0 mm.

22. The nonwoven fabric according to claim 20, wherein the nonwoven fabric has an abrasion resistance of at least Class 2 according to Martindale or wherein the nonwoven fabric has a maximum flexural stiffness with a cantilever of at most 100 mm.

23. The nonwoven fabric according to claim 20, wherein the nonwoven fabric is a nonwoven laminate composed of at least two nonwoven webs or nonwoven fabric layers.

Description

[0074] The invention is explained in more detail below with reference to a drawing that merely represents an embodiment. In the figures in schematic representation:

[0075] FIG. 1 is a vertical section through an apparatus according to the invention,

[0076] FIG. 2 is a vertical section through a part of the apparatus according to FIG. 1,

[0077] FIG. 3 is a plan view of a nonwoven fabric according to the invention, and

[0078] FIG. 4 is a cross-section along line A-A according to FIG. 1.

[0079] FIG. 1 shows an apparatus 14 according to the invention for carrying out the method according to the invention and for making a nonwoven fabric 1 comprising two nonwoven webs 2, 2 of crimped continuous filaments 10. The apparatus preferably and here, comprises two spinning beams 3, 3 that are preferably and here each adapted to produce a spunbonded nonwoven web 2, 2 from crimped continuous filaments 10 in the form of bicomponent filaments. In addition, according to the preferred embodiment, an endlessly circulating foraminous belt 4 is provided for depositing the continuous filaments 10 to form the nonwoven web 2, 2. The apparatus 14 preferably and here comprises a calender roller 5 for introducing an embossing pattern 11 (FIGS. 3 and 4) consisting of a plurality of nonconnected embossments 12 into the nonwoven fabric 1. This calender roller 5 preferably and here is part of a calender 6 comprising a pair of calender rollers 5, 7. Preferably and here the calender roller 5 of the calender 6 has a complementary embossing pattern 15 of embossing elements 16 that preferably each have a pressing area 17 of 0.05 to 0.6 mm.sup.2. Pressing surface 17 refers in particular to the area of the embossing elements 16 of the calender roller 5 provided of making an embossing area 13 of the embossments 12 of the nonwoven fabric 1. Preferably and here according to FIG. 1, the embossing elements 16 of the calender roller 5 are configured to be frustoconical and the pressing area 17 corresponds to the top surface of the frustrated cone. The other or further calender roller 7 of the calender 6 is preferably and here a smooth roller 7 with a smooth outer surface.

[0080] According to a particularly preferred embodiment and here according to FIG. 1, the apparatus 14 has a hot-air main consolidater 8 that is preferably in the travel direction F of the nonwoven fabric downstream of the calender roller 5 or downstream of the calender 6. Preferably and here, the hot-air main consolidater 8 is a hot-air oven. Expediently and here, the apparatus 14 further comprises two preconsolidaters in the form of hot-air preconsolidaters 9, 9. The hot-air preconsolidaters 9, 9 are preferably and here in the travel direction F of the nonwoven fabric 1 upstream of the calender roller 5 or upstream of the calender 6. Preferably and here according to FIG. 1, the hot-air preconsolidaters 9, 9 are each directly downstream of a spinning beam 3, 3 for preconsolidating the deposited nonwoven web 2, 2. A first hot-air preconsolidater 9 is preferably directly downstream of a first spinning beam 3 in the travel direction F of the nonwoven fabric 1, and is then followed by a second spinning beam 3, to which the second hot-air Preconsolidater 9 is immediately downstream. The hot-air preconsolidaters 9, 9 are preferably hot-air knives and/or as hot-air fields.

[0081] Within the scope of the method according to the invention and here according to FIG. 1, a nonwoven web 2 composed of crimped continuous filaments 10 is first made by the first spinning beam 3 and deposited on the foraminous belt 4. The nonwoven web 2 is then preferably and here, preconsolidated by the hot-air preconsolidater 9. Thereafter, a second nonwoven web 2 made of crimped continuous filaments 10 is expediently made by the second spinning beam 3 and deposited on the first nonwoven web 2. The second nonwoven web 2 or the laminate of the first nonwoven web 2 and the second nonwoven web 2 is then recommendably preconsolidated with the second hot-air preconsolidater 9 and then preferably detached from the foraminous belt 4 and fed to the calender 6 comprising the calender roller 5. The calender roller 5 of the calender 6 preferably here introduces an embossing pattern 11 comprising a plurality of embossments 12 into the nonwoven fabric 1 and the nonwoven fabric 1 is expediently consolidated in the process. This is then preferably followed by consolidation or main consolidation of the nonwoven fabric 1 by at least one hot-air main consolidater 8.

[0082] FIG. 2 shows the basic structure of a part of the apparatus 14 according to the invention of making a nonwoven web 2 according to the spunbond method, comprising a spinneret or the spinning beam 3 for spinning the continuous filaments 10 for the spunbonded nonwoven web 2 from continuous filaments 10. The continuous filaments 10 spun by the spinneret or the spinning beam 3 are introduced into a cooler 18 with a cooling chamber 19. Preferably and here, air supply cabins 20, 21 one above the other are provided on two opposite sides of the cooling chamber 19. Air of different temperatures is preferably introduced into the cooling chamber 19 from the air supply cabins 20, 21 one above the other.

[0083] It is recommended and here that a stretcher 22 for stretching the continuous filaments 10 is provided downstream of the cooler 18 in the filament-travel direction. Expediently and here, the stretcher 22 has an intermediate passage 23 that connects the cooler 18 to a stretching shaft 24 of the stretcher 22. Preferably and here, the subassembly comprising the cooler 18, the intermediate passage 23 and the stretching shaft 24 is a closed unit and apart from the supply of cooling air in the cooler 18, no further air is supplied from the outside into this subassembly.

[0084] Expediently and here, a diffuser 25, through which the continuous filaments 10 are guided, adjoins the stretcher 22 in the filament-travel direction. After passing through the diffuser 25, the continuous filaments 10 are preferably and here deposited on a receiving device, here a foraminous belt 4. The foraminous belt 4 is preferably and here an endlessly rotating foraminous belt 4. It is within the scope of the invention that the foraminous belt 4 is permeable to air, so that suction of process air from below through the foraminous belt 4 is possible.

[0085] FIGS. 3 and 4 show a nonwoven fabric 1 according to the invention with at least one nonwoven web 2 of filaments. In this embodiment, the nonwoven fabric 1 comprises two nonwoven webs 2, 2 composed of continuous filaments 10 and is particularly a nonwoven laminate. The continuous filaments 10 may preferably and here be crimped continuous filaments 10. Preferably and here, the nonwoven fabric 1 is a spunbonded nonwoven fabric comprising two spunbonded nonwoven webs 2, 2 composed of crimped continuous filaments 10. In this embodiment, the crimped continuous filaments 10 may be bicomponent filaments with an eccentric core-sheath configuration, wherein the sheath of the continuous filaments 10 preferably consists of or substantially consists of polyethylene and wherein the core of the continuous filaments 10 consists of or substantially consists in particular of at least one polyester and/or polypropylene.

[0086] FIGS. 3 and 4 also show that the nonwoven fabric 1 has an embossing pattern 11, wherein the embossing pattern 11 consists of a plurality of Ralf embossments 12. The embossing pattern 11 is preferably and here a regular embossing pattern 11 whose individual embossments 12 are preferably and here distributed at regular intervals on the nonwoven fabric 1.

[0087] Within the scope of the invention and here, the embossments 12 each have an embossing area 13 of 0.05 to 0.6 mm.sup.2. Embossing area 13 of an embossment 12 means, within the scope of the invention and here, in particular the embossed area of an embossment 12, wherein when determining the size of the embossing area 13, the material overhang or material projection that may be formed during the pressing or embossing process and at least partially enclosing the embossment 12 is not part of the embossing area 13 of an embossment 12. This can be seen particularly in FIG. 4 in the hatched representation. Further preferably and here, the embossing area 13 of the individual embossments 12 of the embossing pattern 11 is the same size or substantially the same size. Preferably and here according to the figures, the embossing areas 13 of the embossments 12 have a punctuate or circular geometry in plan view. Quite particularly preferably and here, the embossing pattern 11 has the same or same-sized embossments 12 or substantially the same or same-sized embossments 12 with a homogeneous distribution of embossments 12 of the same geometry or of substantially the same geometry.

[0088] Within the scope of the invention, the smallest spacing d between two embossments 12 of each of the embossing pattern 11 is 0.6 to 3.0 mm. Smallest spacing d between two embossments 12 means in particular the smallest spacing d between two immediately adjacent embossments 12 of the embossing pattern 11, thus preferably the smallest spacing d between an embossment 12 and the embossment 12 of the embossing pattern 11 that is closest to it. Furthermore, the smallest spacing d between two embossments 12 refers in particular to the smallest spacing d between the embossing boundaries of two embossments 12, i.e. to the smallest spacing between the two embossments 12 along the interposed nonembossed area of the nonwoven fabric 1.

[0089] The thickness h of the nonwoven fabric 1 is expediently 0.15 to 0.75 mm. In the embodiment according to the figures, the thickness h of the nonwoven fabric 1 may be approximately 0.4 mm. Thickness h means the greatest thickness or total thickness of the nonwoven fabric 1 transversely, in particular perpendicularly or substantially perpendicularly to its planar extension in the nonembossed areas of the nonwoven fabric 1. This can be seen particularly in FIG. 4.