Method and apparatus for manufacturing a nonwoven fabric

Abstract

The present invention relates to a method for manufacturing a nonwoven fabric having at least one nonwoven web made of fibers. The fibers are manufactured using at least one fiber manufacturing device. Then, the fibers are deposited on at least one deposition device to form a nonwoven web. The nonwoven web or nonwoven layer is fixed using at least one calendar roller, and the nonwoven fabric is additionally fixed or primarily fixed using at least one thermal fluid-based primary fixing device.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a nonwoven fabric having at least one nonwoven web made of fibers, wherein the fibers are manufactured using at least one fiber manufacturing device, in particular at least one spinning beam, and then the fibers are deposited on at least one deposition device, in particular on a deposition screen belt, to form a nonwoven web. The present invention further relates to an apparatus for manufacturing a nonwoven fabric.

Background Art

[0002] Methods and apparatuses for manufacturing nonwoven fabrics are basically known in various embodiments in practice. Usually, the produced fibers are deposited on a deposition device to form a nonwoven web, which is then pre-fixed to ensure the transportability of the nonwoven web or nonwoven fabric and to ensure that the nonwoven web is not displaced or damaged when passing through the apparatus during transportation. For further fixing or main fixing, the nonwoven fabric is usually supplied to a downstream device. As a downstream device for fixing or main fixing the nonwoven fabric, for example, a calendar having at least one calendar roller, particularly at least one pair of calendar rollers, is known. In this case, in many cases, a calendar roller provided with an embossing element is used, which introduces an embossing pattern consisting of a plurality of embossings into the nonwoven fabric during the fixing process. Nonwoven fabrics treated with at least one calendar do indeed feature advantageous mechanical strength, but these nonwoven fabrics are often thin or have a low volume. Furthermore, although the embossing pattern introduced into the nonwoven fabric using a calendar is advantageous or necessary with respect to the mechanical properties of the nonwoven fabric, it is disadvantageous for aesthetic reasons because the visual properties of the nonwoven fabric are adversely affected thereby. Therefore, in practice, instead of fixing or main fixing the nonwoven fabric, a thermal fluid fixing device or a hot air fixing device, such as a hot air furnace, is also known. Nonwoven fabrics fixed or main fixed using such a fixing device usually feature an advantageous thickness or volume, but often have an undesirable rigidity or poor drapability, and some exhibit an unfavorably low abrasion resistance.

[0003] An acceptable compromise consisting of sufficient mechanical strength, a satisfactory thickness or volume, low rigidity or satisfactory drapability, and sufficient abrasion resistance has hitherto only been achievable by mixing different fiber types into the nonwoven fabric. However, this is time-consuming, and furthermore, the method therefor lacks flexibility in use. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0004] In contrast, the present invention is a method of the type described at the beginning, which can effectively and reliably avoid the above-mentioned drawbacks, and by using it, in particular, advantageous mechanical properties such as sufficient mechanical strength or surface durability, sufficient thickness or volume, low rigidity or satisfactory drapability, and especially, a method for manufacturing a nonwoven fabric characterized by improved abrasion resistance can be provided. At this time, in particular, an optimal compromise between these nonwoven fabric properties is desirable. Furthermore, the present invention is based on the problem of providing a corresponding apparatus for manufacturing nonwoven fabrics and such nonwoven fabrics.

Means for Solving the Problems

[0005] To solve the above technical problem, the present invention teaches a method for manufacturing a nonwoven fabric having at least one nonwoven web made of fibers, wherein the fibers are manufactured using at least one fiber manufacturing device, in particular at least one spinning beam, and the fibers are then deposited on at least one deposition device, in particular on a deposition screen belt, to form a nonwoven web, and the nonwoven web or nonwoven fabric is fixed using at least one calendar roller, in particular at least one calendar or a pair of calendar rollers provided with this calendar roller, and the nonwoven fabric is further fixed or primarily fixed using at least one thermal fluid type primary fixing device, in particular at least one hot air type primary fixing device.

[0006] The fact that the nonwoven fabric has at least one nonwoven web made of fibers means, in particular within the framework of the present invention, that the nonwoven fabric has at least one nonwoven web or nonwoven layer made of the manufactured and deposited fibers. According to one embodiment, the nonwoven fabric may have only one nonwoven web or nonwoven layer, or may have a plurality of laminated nonwoven webs or nonwoven layers combined to form a nonwoven fabric laminate.

[0007] The term "fixed" or "primary fixation" means, within the framework of the present invention, the fixation of the nonwoven fabric, which in particular results in a higher degree of fixation of the nonwoven fabric compared to pre-fixation. It is within the framework of the present invention that by using primary fixation, a lower or higher degree of fixation of the nonwoven fabric is achieved compared to when using fixation, or that by using primary fixation, the same or essentially the same degree of fixation of the nonwoven fabric is achieved as with fixation.

[0008] According to one preferred embodiment of the present invention, the nonwoven fabric is produced as a spunbond nonwoven fabric having at least one spunbond nonwoven web or at least one spunbond nonwoven layer. It is possible to produce the nonwoven fabric as a nonwoven laminate consisting of at least two spunbond nonwoven webs or at least two spunbond nonwoven layers. However, it is also possible for the nonwoven fabric or the nonwoven laminate to have at least one meltblown nonwoven web or meltblown nonwoven layer. Furthermore, it is within the framework of the method of the present invention that the nonwoven fabric as a nonwoven laminate is produced from at least three, for example at least four, nonwoven webs or nonwoven layers. The individual nonwoven webs or nonwoven layers can be deposited as spunbond nonwoven webs or nonwoven layers, respectively. However, in principle, the nonwoven laminate can also be produced using at least one meltblown nonwoven web or meltblown nonwoven layer. The spunbond nonwoven web or spunbond nonwoven layer is preferably deposited from endless filaments or crimped endless filaments, respectively, which will be explained in more detail below.

[0009] The term "hot fluid" means, within the framework of the present invention, a temperature-controlled or heated fluid. Preferably, the hot fluid is a temperature-controlled or heated gas, particularly preferably hot air (heated air). However, in principle, the hot fluid can also be a temperature-controlled or heated liquid, for example water.

[0010] One particularly preferred embodiment of the method of the present invention is characterized in that the nonwoven fabric is peeled off from the deposition device before fixation using at least one calendar roller and / or before or during fixation using at least one thermal-fluid main fixation device. Particularly preferably, not only the fixation using at least one calendar roller or at least one calendar provided with this calendar roller, but also the fixation or main fixation using at least one thermal-fluid main fixation device is carried out after peeling the nonwoven fabric from the deposition device. For this purpose, expediently, after peeling from the deposition device, the nonwoven fabric is delivered to the calendar roller or calendar or thermal-fluid main fixation device. In principle, it is also within the scope of the present invention to carry out the fixation or main fixation using at least one hot-air main fixation device on or above the deposition screen belt and, in particular, only then to peel the nonwoven fabric from the deposition device.

[0011] It has been found to be particularly effective within the scope of the method of the present invention to carry out the fixation of the nonwoven fabric using at least one calendar roller, in particular at least one calendar or calendar roller pair provided with this calendar roller, before or after the fixation or main fixation of the nonwoven fabric using at least one thermal-fluid main fixation device, in particular at least one hot-air main fixation device. Very particularly preferably, especially after peeling from the deposition device, the nonwoven fabric is first fixed using at least one calendar roller, in particular at least one calendar or calendar roller pair provided with this calendar roller, and then fixed or main-fixed using at least one thermal-fluid main fixation device, in particular at least one hot-air main fixation device. This permutation of the fixation steps has been found to be particularly effective within the scope of the present invention and for solving the above technical problem.

[0012] Where recommended, the nonwoven fabric is first pre-fixed, after deposition on the deposition device and before fixing or main fixing, using at least one pre-fixing device, in particular at least one pre-fixing device following, especially directly following, said at least one fiber production device or said at least one spinning beam, in particular at least one thermal fluid pre-fixing device, preferably at least one hot air pre-fixing device. Therefore, said pre-fixing is carried out, in particular, before fixing using at least one calendar roller or at least one calendar and before fixing or main fixing using at least one thermal fluid main fixing device. Said pre-fixing step ensures, in particular, the transportability of the deposited nonwoven web or nonwoven fabric and, according to a preferred embodiment, in addition the peelability of the nonwoven fabric from the deposition device, as well as the reliable handover to one of the devices provided in the present invention for fixing said nonwoven fabric. According to one preferred embodiment of the method according to the invention, when producing a nonwoven fabric having at least two nonwoven webs made of fibers, it is preferably carried out, for each nonwoven web, a pre-fixing using a pre-fixing device or a thermal fluid pre-fixing device arranged, in particular directly, after each fiber production device or spinning beam, after deposition of each nonwoven web.

[0013] It is within the scope of the method according to the invention that the at least one heat-fluid pre-fixing device or hot-air pre-fixing device is formed as a hot-air knife and / or as a hot-air field. However, in principle, the pre-fixing device can also be at least one roller or smoothing roller, in particular a roller pair or smoothing roller pair. When the non-woven fabric is produced using only one non-woven web in one embodiment, it is preferred to use a hot-air knife as the pre-fixing device. When the non-woven fabric is produced using a plurality of non-woven webs or non-woven layers in a preferred embodiment, in particular for the topmost or last-deposited non-woven web or non-woven layer, a hot-air knife is used as the pre-fixing device, and for the remaining non-woven webs or non-woven layers, in particular, a hot-air knife and a hot-air field are used as the pre-fixing device. In the latter case, a residence time of hot-air exposure exceeding 0.1 seconds has proven to be particularly effective.

[0014] It has been found to be particularly effective within the scope of the present invention that the at least one heat-fluid main-fixing device or the at least one hot-air main-fixing device is formed as a hot-air furnace, particularly preferably as an omega oven and / or as a multi-drum oven and / or as a single-belt oven and / or as a double-belt oven. Expediently, the fixing or main-fixing using at least one heat-fluid main-fixing device is carried out by applying at least one heat fluid to one or both sides of the non-woven fabric in the at least one heat-fluid main-fixing device.

[0015] It has been found that it is even more particularly effective within the framework of the present invention for the at least one heat-fluid main fixing device or the at least one hot-air main fixing device to be formed as a hot-blast stove, particularly preferably as a hot-air field and / or as a multi-drum oven and / or as a single-belt oven and / or as a double-belt oven. According to one embodiment of the present invention, the fixing or main fixing using at least one heat-fluid main fixing device is carried out by applying at least one heat fluid to one or both sides of the nonwoven fabric in the at least one heat-fluid main fixing device and particularly before peeling from the deposition device, whereupon the nonwoven fabric is then, inter alia, fixed using at least one calendar roller after peeling, particularly using at least one calendar or a pair of calendar rollers provided with this calendar roller. Furthermore, it is within the framework of the present invention to provide at least two heat-fluid main fixing devices, whereupon, preferably, the first fixing or main fixing of the nonwoven fabric is carried out using the first heat-fluid main fixing device before peeling the nonwoven fabric from the deposition device, and, inter alia, the second or further fixing or main fixing is carried out using the second heat-fluid main fixing device after peeling the nonwoven fabric from the deposition device and particularly preferably after fixing using at least one calendar roller, particularly using at least one calendar or a pair of calendar rollers provided with this calendar roller. Therefore, in this example, the at least one calendar roller is preferably arranged between the two heat-fluid main fixing devices in the transport direction F of the nonwoven fabric.

[0016] According to a particularly preferred embodiment of the method according to the invention, the residence time of the nonwoven fabric in the heat-fluid main fixing device is from 0.4 seconds to 25 seconds, preferably from 1 second to 15 seconds, and / or the fluid velocity of the fluid in the heat-fluid main fixing device is from 0.4 to 3 m / s, particularly from 0.5 to 2 m / s.

[0017] The surface temperature T1 of the at least one calendar roller, in particular of at least one calendar or calendar roller pair comprising this calendar roller, is higher than the fluid temperature T2 of the at least one thermal fluid-based main fixing device, especially by 0.5 °C to 10 °C, preferably by 1 °C to 5 °C, or lower than the fluid temperature T2 of the at least one thermal fluid-based main fixing device, or is the same as or essentially the same as the fluid temperature T2 of the at least one thermal fluid-based main fixing device, which is within the scope of the present invention. Within the scope of the present invention, the at least one calendar roller, in particular the at least one calendar or calendar roller pair comprising the calendar roller, is preferably a heated calendar roller or a heated calendar. Depending on the temperature conditions between the surface temperature of the at least one calendar roller or calendar and the fluid temperature of the at least one thermal fluid-based main fixing device, (in particular in relation to the residence time and / or fluid velocity described above), the nonwoven fabric can be produced very flexibly, which is characterized by an optimal compromise of their properties, and as a result, it is possible to provide a method that can very flexibly, simply and reliably solve the technical problems described above.

[0018] In principle, manufacturing the fibers of the at least one nonwoven web as staple fibers or the at least one nonwoven web containing staple fibers is within the scope of the present invention. According to a preferred embodiment, the fibers of the at least one nonwoven web are produced as endless filaments. Particularly preferably, within the scope of the method according to the present invention, the fibers of all nonwoven webs are produced as endless filaments. Here, within the scope of the present invention, the fibers mean, in particular, endless filaments. Endless filaments differ from staple fibers, for example, in that they have a clearly shorter length, such as from 1 mm to 60 mm, in terms of their substantially endless length.

[0019] One particularly preferred embodiment of the method according to the invention is characterized in that the fibers of the at least one nonwoven web are produced or spun as endless filaments. In particular, the fibers of the at least one nonwoven web or of at least one nonwoven web of the nonwoven fabric are produced as endless filaments from at least one thermoplastic plastic, preferably from at least one polyolefin. The at least one polyolefin is preferably polypropylene and / or polyethylene, as recommended. In principle, the endless filaments can also be produced from other thermoplastic plastics, such as polyesters, such as polyethylene terephthalate (PET) and / or polylactide (PLA), and from mixtures of the above thermoplastic plastics. According to one embodiment, copolymers of the above thermoplastic plastics are used. Ordinary additives, such as plasticizers, fillers, colorants and similar agents, may be metered into the above thermoplastic plastics. It is within the scope of the invention that the endless filaments of the at least one nonwoven web or of at least one nonwoven web of the nonwoven fabric are produced as spunbond endless filaments. In principle, the endless filaments of the at least one nonwoven web or of the nonwoven web of the nonwoven fabric can also be produced as meltblown endless filaments.

[0020] According to a particularly preferred embodiment of the method according to the invention, the fibers of the at least one nonwoven web are produced or spun as crimped endless filaments, where the endless filaments or crimped endless filaments are particularly preferably produced or spun as multicomponent filaments or very particularly preferably as bicomponent filaments.

[0021] In this context, it has been found to be particularly effective that the multi-component filament or bicomponent filament comprises a first (especially low melting point) component which consists of or consists essentially of at least one thermoplastic, in particular at least one polyolefin, especially polyethylene and / or polypropylene, and / or that the multi-component filament or bicomponent filament comprises a second or further (especially higher melting point) component which consists of or consists essentially of at least one thermoplastic, in particular at least one polyester and / or polypropylene. The term low melting point component, especially the first low melting point component, within the framework of the present invention means in particular a component of the multi-component filament or bicomponent filament which has a lower melting temperature compared to the higher melting point component, especially the second or further higher melting point component of the multi-component filament or bicomponent filament. The low melting point component or the first low melting point component of the multi-component filament or bicomponent filament is in particular a binding component for the multi-component filament or bicomponent filament within the framework of the present invention.

[0022] As the polyester, within the framework of the present invention, in particular polyethylene terephthalate (PET) and / or polylactide (PLA) are suitable. In one embodiment, a copolymer of the plastics is used. Here or hereinafter, when referring to a component of a multi-component filament or bicomponent filament, especially a plastic or polymer, as "consisting essentially of", this means in particular that the component or polymer is present in a proportion of at least 95% by weight, especially at least 97% by weight, preferably at least 98% by weight. The remaining percentage by weight can in particular consist of additives such as plasticizers, fillers, colorants and the like.

[0023] According to one particularly preferred embodiment of the present invention, said first (especially low melting point) component of the multicomponent filament or bicomponent filament is formed based on polyethylene and, in particular, consists of polyethylene or consists essentially of polyethylene. According to another preferred embodiment, the first (especially low melting point) component of the multicomponent filament or bicomponent filament is formed based on polypropylene and preferably consists of polypropylene or consists essentially of polypropylene. Also, within the scope of the present invention, at least one polypropylene copolymer can be used instead of or in addition to polypropylene.

[0024] Said second or further (especially higher melting point) component of the multicomponent filament or bicomponent filament is, in a preferred embodiment of the present invention, formed based on at least one polyester and / or based on polypropylene. Particularly preferably, said second or further (especially higher melting point) component of the multicomponent filament or bicomponent filament consists of at least one polyester and / or consists of polypropylene. For said second or further component, at least one polypropylene copolymer can be used instead of or in addition to polypropylene, and, in particular, at least one polyester copolymer can be used instead of or in addition to polyester. As the polyester, particularly preferably polyethylene terephthalate (PET) and / or polylactide (PLA) are suitable, and as the polyester copolymer, in particular, PET copolymer (Co-PET) is suitable. It is also within the scope of the present invention that a polylactide copolymer (Co-PLA) is used as the first (especially low melting point) component and polylactide (PLA) is used as the second or further (especially higher melting point) component.

[0025] The endless filament, especially the crimped endless filament, is produced or spun as a multicomponent filament or a bicomponent filament having a side-by-side configuration and / or a core-sheath configuration, especially an eccentric core-sheath configuration, and in this case preferably, the first (especially low melting point) component is the sheath component and the second (especially higher melting point) component is the core component, within the framework of the method of the present invention. When the endless filament is produced or spun as a multicomponent filament or a bicomponent filament having a core-sheath configuration, within the framework of the present invention, in principle, it is also possible for this to be a concentric core-sheath configuration.

[0026] In a preferred embodiment, when the endless filament or the crimped endless filament is produced or spun as a multicomponent filament or a bicomponent filament having an eccentric core-sheath configuration, within the framework of the present invention, it is possible for not only the sheath of the filament but also the core of the filament to be formed in a circular shape when looking at the cross-section of the filament. In one of yet another preferred embodiments of the present invention, the multicomponent filament or the bicomponent filament is produced or spun as a multicomponent filament or a bicomponent filament having an eccentric core-sheath configuration, and the core of these filaments is formed in a bow shape when looking at the cross-section of the filament, and has an arcuate peripheral section and a linear peripheral section with respect to its periphery, resulting in a so-called D-shaped core when looking at the cross-section of the filament.

[0027] When the endless filament or crimped endless filament is produced or spun as a multi-component filament or bicomponent filament having at least one of the first (especially low melting point) components and at least one of the second or yet another (especially higher melting point) components within the framework of the method according to the invention, the proportion of the first (especially low melting point) component of the multi-component filament or bicomponent filament in the at least one nonwoven web of the nonwoven fabric is from 10 to 90% by weight, especially from 20 to 70% by weight, preferably from 30 to 50% by weight, based on the components of the multi-component filament or bicomponent filament.

[0028] The design of the fibers as multi-component filaments or bicomponent filaments, especially multi-component filaments or bicomponent filaments having a first (especially low melting point) component and a second or yet another (especially higher melting point) component, and further, the preferred design of multi-component filaments or bicomponent filaments having a side-by-side configuration and / or a core-sheath configuration, preferably an eccentric core-sheath configuration, is based on the finding that the nonwoven fabric properties can be adjusted very flexibly by these components or configurations of the filaments, and that in particular, in combination with the fixing according to the invention using at least one calendar roller and at least one thermo-fluid main fixing device, a nonwoven fabric can be produced that achieves a particularly advantageous compromise of nonwoven fabric properties for solving the above technical problem of the invention.

[0029] In this context, it has been found to be very particularly effective that the surface temperature T1 of the at least one calendar roller, in particular of at least one calendar or calendar roller pair provided with this calendar roller, and / or the fluid temperature T2 of the at least one thermal fluid main fixing device satisfy the following conditions with respect to the melting temperature Tm of the first (especially low melting point) component of the multi-component filament or bicomponent filament: (Tm - 15 °C) < T1 and / or T2 < (Tm + 15 °C), especially (Tm - 10 °C) < T1 and / or T2 < (Tm + 10 °C), preferably (Tm - 8 °C) < T1 and / or T2 < (Tm + 8 °C), particularly preferably (Tm - 7 °C) < T1 and / or T2 < (Tm + 7 °C), very particularly preferably (Tm - 6 °C) < T1 and / or T2 < (Tm + 6 °C), for example (Tm - 5 °C) < T1 and / or T2 < (Tm + 5 °C). Within the framework of the method according to the invention, the melting temperature Tm of the first (especially low melting point) component is determined in particular using dynamic differential scanning calorimetry (DSC) in accordance with ISO 11357-3:2011. Therefore, in particular, the surface temperature T1 of the at least one calendar roller and / or the fluid temperature T2 of the at least one thermal fluid main fixing device satisfy the conditions described above. In this case, the surface temperature T1 can preferably have the relationship described above with respect to the fluid temperature T2, so that T1 can be higher than T2, or lower than T2, or the same as T2. When the thermal fluid main fixing device, in particular the hot air main fixing device, is a hot air furnace according to a preferred embodiment, the fluid temperature corresponds, in other respects, within the framework of the invention, in particular to the temperature of the hot air during this hot air fixing in the hot air furnace.

[0030] According to a highly preferred embodiment of the method according to the invention, an embossing pattern consisting of a plurality of (preferably non-connected to each other) embossings is introduced into the nonwoven using said at least one calendar roller. It is within the scope of the invention that the calendar roller is part of a calendar having at least one calendar roller pair in a particularly preferred embodiment, and that at least one, in particular one, of the two calendar rollers of the calendar or the calendar roller pair is, inter alia, a calendar roller for introducing an embossing pattern consisting of a plurality of embossings into the nonwoven. For this purpose, the calendar roller preferably has a complementary embossing pattern consisting of embossing elements. This will be explained in more detail below. The other or further roller of the calendar or the calendar roller pair is expediently a smoothing roller having a smooth outer surface. Therefore, within the scope of the method according to the invention, the nonwoven is fixed using a calendar comprising at least one calendar roller for introducing an embossing pattern consisting of a plurality of embossings into the nonwoven and, more preferably, at least one smoothing roller. In this case, the embossing pattern is preferably introduced into the nonwoven from only one nonwoven surface. However, nevertheless, preferably the embossing pattern is present on both nonwoven surfaces in the resulting nonwoven, wherein the embossing depth is distributed differently, in particular, on both nonwoven surfaces. It is within the scope of the invention that when using a calendar consisting of at least one calendar roller pair, one of the calendar rollers having an embossing element for introducing an embossing pattern consisting of a plurality of embossings into the nonwoven and one calendar roller being formed as a smoothing roller, both calendar rollers have different surface temperatures for fixing the nonwoven. In this case, it is preferred that the calendar roller having the embossing element has a higher surface temperature. In this case, if the temperatures of the individual calendar rollers are different, the surface temperature T1 described above particularly means the temperature of the calendar roller having the embossing element.

[0031] Within the framework of the present invention, the term "embossment" particularly means a densified portion of a non-woven fabric, i.e., the non-woven fabric has a particularly thinner thickness compared to the areas of the non-woven fabric that have not been embossed, and the fibers of the non-woven fabric are at least partially bonded or fused to each other, especially by the action of pressure and / or temperature. According to a very particularly preferred embodiment of the method according to the present invention, each embossment has an embossed surface ranging from 0.05 to 0.6 mm 2 up to, especially from 0.06 to 0.4 mm 2 up to, preferably from 0.07 to 0.25 mm 2 up to, particularly preferably from 0.08 to 0.15 mm 2 up to, and very particularly preferably from 0.09 to 0.12 mm 2 and having an embossed surface up to. Each embossment having an embossed surface less than 0.3 mm 2 especially less than 0.2 mm 2 less than, preferably less than 0.18 mm 2 less than, particularly preferably less than 0.15 mm 2 less than, very particularly preferably less than 0.12 mm 2 less than, for example, 0.1 mm 2 having an embossed surface less than is within the framework of the present invention. These embodiments are based on the finding that by using an embossed pattern consisting of embossments of this special design, especially by using a relatively small embossed surface, the visual recognition of the embossed pattern by the human eye can be at least significantly reduced, and as a result, the influence on the visual properties of the resulting non-woven fabric can be almost completely avoided.

[0032] Within the framework of the present invention, the term embossed pattern means, in particular, a pattern formed from a plurality of embosses on a nonwoven fabric. The embossed pattern can be a regular embossed pattern and / or an irregular embossed pattern. Preferably, the embossed pattern is a regular embossed pattern. In this case, the individual embosses are distributed on the nonwoven fabric that results, among other things, at regular intervals, preferably at the same intervals. More preferably, the embossing surfaces of the individual embosses of the embossed pattern are of the same size or essentially of the same size. It has also proven advantageous for the geometric shape of the embossing surface of each emboss to be the same or essentially the same. It is highly particularly preferred that the embossed pattern has embosses of the same or the same size, or essentially the same or the same size, and that the embosses of the same geometric shape or essentially the same geometric shape are uniformly distributed. However, in principle, it is also possible for each emboss of the embossed pattern to have a different size and / or a different geometry from one another, and / or for the embosses to be arranged on the nonwoven fabric in an irregular embossed pattern. Within the framework of the present invention, the geometry of an emboss means, among other things, in particular the geometry of the embossing surface of the emboss as seen from above.

[0033] Within the framework of the present invention, the embossed surface of an embossment particularly means the embossed surface of the embossment, and in determining the area of the embossed surface, material protrusions or material ridges that are formed, in some cases, during the pressing or embossing process and at least partially surround the embossment are not, in particular, part of the embossed surface of the embossment. In the case of an embossment or an embossed surface having a dot-shaped or circular geometry when viewed from above, the embossed surface of the embossment corresponds, for example, to the area of the dot-shaped or circular embossment, and in this case, material protrusions or material ridges surrounding the embossment, in some cases, are not added to the embossed surface of the embossment. The fact that the embossments of the nonwoven fabric according to the present invention each have an embossed surface within the range described above means, in particular, within the framework of the present invention, that at least 95%, particularly at least 97%, of all the embossments of the nonwoven fabric have an embossed surface within the above range. Particularly preferably, all the embossments of the nonwoven fabric have an embossed surface within the above range. The embossed surface area of the embossment can be determined, within the framework of the present invention, in particular by means of a reflected or transmitted illumination 2D microscope, and / or a scanning electron microscope (REM) and / or microcomputer tomography (μCT). In the corresponding image evaluation, preferably, the shape that forms the basis of the embossed surface geometry, or a geometry that coincides with or essentially coincides with the embossed surface geometry, is used as the basis, and for the evaluation, it is placed on the embossed surface of each optically imaged embossment.

[0034] It is within the scope of the method according to the invention that the minimum distance d between two embosses of the emboss pattern is from 0.6 to 3.0 mm, especially from 0.8 to 2.5 mm, preferably from 0.9 to 2.0 mm, particularly preferably from 0.95 to 1.8 mm, and very particularly preferably from 1.0 to 1.5 mm, respectively. Advantageously, the minimum distance d between two embosses of the emboss pattern is at least 0.6 mm, especially at least 0.8 mm, preferably at least 1.0 mm, particularly preferably at least 1.4 mm, and very particularly preferably at least 2.0 mm, respectively. Herein, the minimum distance d between two embosses of the emboss pattern particularly means the minimum distance between two directly adjacent embosses of the emboss pattern, that is, preferably, the minimum distance between one emboss and the emboss closest to it in the emboss pattern. Further, the minimum distance d between two embosses of the emboss pattern particularly refers to the minimum distance between the respective emboss boundaries of the two embosses, that is, the minimum distance between these two embosses along the non-embossed nonwoven fabric surface existing between the two embosses. This embodiment is particularly based on the finding that the visual recognition of the emboss pattern composed of embosses can be further reduced thereby. The minimum distance described above between two embosses of the emboss pattern preferably applies to at least 95%, especially at least 97% of all the embosses of the nonwoven fabric. Particularly preferably, the above-mentioned minimum distance between two embosses applies to all the embosses of the nonwoven fabric.

[0035] Another preferred embodiment of the method according to the invention is that the embossed pattern is generated on condition that the ratio of the total embossed area of the embossed pattern to the total surface area of the nonwoven fabric is from 2 to 15%, in particular from 2.5 to 12%, preferably from 3 to 8%, particularly preferably from 3.5 to 6%, and most preferably from 3.8 to 5.2%. It is within the scope of the present invention that the embossed pattern is generated on condition that the ratio of the total embossed area of the embossed pattern to the total surface area of the nonwoven fabric is less than 10%, in particular less than 8%, preferably less than 6.5%, particularly preferably less than 5.5%, and very particularly preferably less than 5%. By the above-mentioned ratio of the total embossed area of the embossed pattern to the total surface area of the nonwoven fabric, the visual recognizability of the embossed pattern consisting of the embosses can be further reduced. In this connection, the total embossed area of the embossed pattern particularly means the sum total of the total embossed area of the embossed pattern. The total surface area of the nonwoven fabric particularly means, within the scope of the present invention, the entire nonwoven fabric surface including the embossed area and the non-embossed area.

[0036] It is within the scope of the method of the present invention that the calendar roller or the calendar line load of the calendar is from 4 N / mm to 60 N / mm, preferably from 10 N / mm to 40 N / mm, particularly preferably from 15 N / mm to 35 N / mm, and very particularly preferably from 20 N / mm to 30 N / mm. More preferably, the calendar line load is from 2 to 20 N / mm, in particular from 3 to 15 N / mm, preferably from 4 to 8 N / mm, per percentage of the total embossed area of the embossed pattern as described above with respect to the total surface area of the nonwoven fabric.

[0037] Particularly preferably, the nonwoven fabric is produced from at least two nonwoven webs made of fibers. For this purpose, first, the first fibers are produced from at least one first fiber production device, particularly from at least one first spinning beam, and then deposited on a deposition device, particularly on a deposition screen belt, to form a nonwoven web. And the second fibers are produced from at least one second fiber production device, particularly from at least one second spinning beam, and then deposited on the first nonwoven web to form a second nonwoven web. And the assembly or nonwoven fabric composed of the at least two nonwoven webs is fixed using at least one calendar roller, particularly using at least one calendar or a pair of calendar rollers equipped with this calendar roller. And further, fixing or main-fixing the nonwoven fabric using at least one thermal fluid main fixing device, particularly using at least one hot air main fixing device, is within the scope of the method according to the present invention. Within the framework of such an embodiment, expediently, at least one pre-fixing device, particularly at least one thermal fluid pre-fixing device, preferably at least one hot air pre-fixing device, is arranged after or immediately after each fiber production device or each spinning beam respectively. And the deposited nonwoven web is preferably pre-fixed using each pre-fixing device first, respectively, before the fixing or main-fixing of the nonwoven fabric, as already described above.

[0038] Within the framework of the method according to the invention, when the nonwoven fabric is produced using at least two nonwoven webs made of fibers, it is particularly preferred that the fibers are produced as endless filaments, in particular as crimped endless filaments, and are each deposited as a spunbond nonwoven web. In this case, the properties of the fibers or endless filaments of the different nonwoven webs or nonwoven layers of the resulting nonwoven fabric can be different. For example, the endless filaments of the first nonwoven web produced using the first spinning beam can have a lower average fineness than the endless filaments of the second nonwoven web produced using the second spinning beam, resulting in a so-called fineness gradient. It has been found that it is particularly effective for the fibers of at least one nonwoven web or nonwoven layer belonging to the outer surface of the nonwoven fabric to be produced as crimped endless filaments and / or as staple fibers. Thereby, in particular, the flexibility of the nonwoven fabric can be improved and the bending stiffness can be reduced.

[0039] To solve the above technical problem, the present invention further provides an apparatus for producing a nonwoven fabric having at least one nonwoven web made of fibers, in particular for implementing the method described above, the apparatus comprising at least one fiber production device, in particular at least one spinning beam, and at least one deposition device for spinning the fibers into a nonwoven web, in particular at least one deposition screen belt, and further comprising at least one calendar roller, in particular a calendar or a pair of calendar rolls comprising this calendar roller, provided for fixing the nonwoven fabric, and in addition, at least one thermal fluid main fixing device, in particular at least one hot air main fixing device, present for fixing or main fixing the nonwoven fabric, which teaches the above apparatus.

[0040] The device comprises at least one pre - fixing device, in particular a pre - fixing device arranged, especially immediately, after the at least one fiber - manufacturing device or the at least one spinning beam, in particular at least one thermal - fluid pre - fixing device, preferably at least one hot - air pre - fixing device, for pre - fixing the non - woven fabric, wherein it is within the scope of the invention that the at least one thermal - fluid pre - fixing device or the at least one hot - air pre - fixing device is particularly preferably configured as a hot - air knife and / or a hot - air field.

[0041] For the purpose, the deposition screen belt of the device according to the invention is an endless circulating deposition screen belt. It is within the scope of the invention that at least one of the fiber manufacturing devices or at least one of the spinning beams is configured to produce a spunbond nonwoven web from endless filaments, in particular from crimped endless filaments. If the nonwoven fabric is formed as a nonwoven laminate consisting of at least two nonwoven webs or nonwoven layers in one embodiment of the invention, it is within the scope of the invention that there are at least two fiber manufacturing devices, in particular at least two spinning beams, and especially that all fiber manufacturing devices or spinning beams are configured to produce a spunbond nonwoven fabric from endless filaments, in particular from crimped endless filaments. Very particularly preferably, at least one of the fiber manufacturing devices or at least one of the spinning beams of the device according to the invention, especially all fiber manufacturing devices or all spinning beams, are designed to produce multicomponent filaments or bicomponent filaments. Furthermore, it is within the scope of the invention that the device is configured to produce at least one nonwoven web from crimped endless filaments. In particular, at least one fiber manufacturing device or at least one spinning beam is designed for the production of crimped endless filaments. If a plurality of spinning beams are used for the device according to the invention, at least one spinning beam, or at least two spinning beams, or all spinning beams are designed to produce crimped endless filaments.

[0042] One very advantageous form of the invention is characterized in that there is provided at least one cooling device for cooling the fibers or filaments spun using at least one fiber production device or at least one spinning beam, and a stretching device arranged behind the cooling device for stretching the fibers or filaments. Advantageously, at least one diffuser is installed behind the stretching device in the flow direction of the fibers or filaments. One very recommended embodiment of the invention is characterized in that the connecting machine consisting of the cooling device and the stretching device is configured as a closed-system connecting machine, and in this connecting machine, except for the supply of cooling air into the cooling device, no further air supply from the outside is carried out. Advantageously, the fibers or filaments emerging from the diffuser are deposited directly onto a deposition device or a deposition screen belt.

[0043] According to a preferred embodiment of the device according to the invention, the at least one calendar roller, in particular a calendar or a pair of calendar rollers comprising this calendar roller, is arranged in the conveying direction F of the nonwoven fabric, in front of or behind the at least one main fixing device of the thermal fluid type. According to a preferred embodiment, the at least one main fixing device of the thermal fluid type is arranged in the conveying direction F of the nonwoven fabric, in front of the calendar roller, in particular in front of the calendar comprising this calendar roller. According to a very particularly preferred embodiment, the at least one main fixing device of the thermal fluid type is arranged in the conveying direction F of the nonwoven fabric, behind the calendar roller, in particular behind the calendar comprising this calendar roller.

[0044] According to yet another preferred embodiment of the device according to the invention, said at least one calendar roller has a complementary embossing pattern consisting of embossing elements for introducing an embossing pattern consisting of a plurality of embosses into said nonwoven fabric. By using such a calendar roller having a complementary embossing pattern consisting of embossing elements, it is possible to introduce into the nonwoven fabric the embossing pattern consisting of embosses already described above. Advantageously, said calendar or said pair of calendar rollers has, in addition to this calendar roller for introducing an embossing pattern consisting of embosses into said nonwoven fabric, a second or yet another calendar roller configured as a smoothing roller having a smooth outer surface.

[0045] Said embossing elements of the complementary embossing pattern of said calendar roller are each from 0.05 to 0.6 mm 2 up to, preferably from 0.06 to 0.4 mm 2 up to, more preferably from 0.07 to 0.25 mm 2 up to, particularly preferably from 0.08 to 0.15 mm 2 up to, very particularly preferably from 0.09 to 0.12 mm 2It has been found to be particularly effective to have a pressing surface up to [a certain point]. The pressing surface, within the framework of the present invention, particularly means the surface of the embossing element of a calendar roller provided for generating the embossing surface of the emboss. When the embossing element of the calendar roller is formed as a cylindrical embossing element, for example, to generate an embossing surface having a dot-shaped or circular geometry when viewed from above, the pressing surface of the embossing element particularly corresponds to the surface of this cylindrical upper surface. When the said embossing element of the calendar roller is formed, for example, in a frustum of a cone shape (that is, with a flank angle) to generate an embossing surface having a dot-shaped or circular geometry when viewed from above, the said pressing surface of the embossing element particularly corresponds to the upper surface of the frustum of the cone. One embodiment of the present invention utilizes a plurality of flank angles for the embossing element, and in this case, the embossing element preferably has a larger flank angle the more it is directed towards the base surface of the calendar roller in the region provided for contact with the non-woven fabric. At this time, the gradient of the flank angle can occur stepwise or continuously. The calendar roller for introducing the embossing pattern from the embossing element into the non-woven fabric is, within the framework of the present invention, formed such that, with respect to its complementary embossing pattern or with respect to the arrangement and form of the embossing element, in particular, an embossing pattern having the parameters or characteristics described above can be realized in the non-woven fabric using it.

[0046] It is within the framework of the present invention that the embossing elements of the complementary embossing pattern of the at least one calendar roller each have an embossing height in the range from 0.3 to 1.2 mm, preferably from 0.4 to 0.9 mm, and particularly preferably from 0.5 to 0.8 mm. At this time, the embossing height particularly means the difference in height between the pressing surface of the embossing element and the base surface of the calendar roller. This embodiment is based on the finding that in a calendaring process using such a calendar roller, the densification of the non-woven fabric can be at least significantly minimized.

[0047] To solve the above technical problem, the present invention further teaches a non-woven fabric manufactured according to the method described above and / or using the apparatus described above.

[0048] According to a particularly preferred embodiment of the nonwoven fabric according to the present invention, the nonwoven fabric has an embossed pattern consisting of a plurality of (especially non-connected to each other) embosses, and in this case, these embosses are each, inter alia, from 0.05 to 0.6 mm 2 up to, preferably from 0.06 to 0.4 mm 2 up to, more preferably from 0.07 to 0.25 mm 2 up to, particularly preferably from 0.08 to 0.15 mm 2 up to, very particularly preferably from 0.09 to 0.12 mm 2 up to, and have an embossed surface, and / or the embossed surface of the emboss has, when viewed from above, at least one geometric shape selected from the group of "dot-shaped or circular, elliptical, square, rectangular, rhombic, polygonal, linear, wavy". It is preferable that the embossed surfaces or embosses of the embossed pattern each have the same geometric shape or an essentially the same geometric shape. However, it is also basically within the scope of the present invention for the embossed pattern to have embossed surfaces or embosses of different geometric shapes. One very particularly preferred embodiment of the present invention is characterized in that the embossed surface of the emboss or all embosses is dot-shaped or circular when viewed from above. In other respects, within the scope of the present invention, the geometric shape of the emboss means, in particular, the geometric shape of the embossed surface of the emboss when viewed from above.

[0049] One preferred embodiment of the nonwoven fabric according to the present invention is characterized in that the aspect ratio of the embossed surface of the embossment is less than 4, preferably less than 3, particularly preferably less than 2, for example equal to 1, respectively. In this connection, the aspect ratio of the embossed surface particularly means the ratio of the maximum length or the longitudinal extension of the embossed surface of one embossment to the maximum width or the widthwise extension of the embossed surface of the same embossment, for example, the ratio of the lengths of the symmetry axes. In the case of a dot-shaped or circular geometry when viewed from above the embossed surface of one embossment, the aspect ratio is, for example, equal to 1. In the case of an elliptical geometry when viewed from above the embossed surface of one embossment, the aspect ratio corresponds to, for example, the ratio of the length of the major axis or the major semi-axis to the length of the minor axis or the minor semi-axis of the ellipse. In the case of a rectangular geometry when viewed from above the embossed surface of one embossment, the aspect ratio corresponds to, for example, the ratio of the length of the rectangle to the width of the rectangle. In the case of a rhombic geometry when viewed from above the embossed surface of one embossment, the aspect ratio corresponds to, for example, the ratio of the length of the longer diagonal to the length of the shorter diagonal of the rhombus. In the case of a square geometry when viewed from above the embossed surface of one embossment, the aspect ratio is equal to 1. In the case of a curve, particularly, the aspect ratio of the surrounding rectangle represents the aspect ratio of the embossed surface.

[0050] The nonwoven fabric has a basis weight of less than 200 g / m 2 and particularly less than 150 g / m 2 and especially less than 100 g / m 2 preferably less than 75 g / m 2 particularly preferably less than 50 g / m 2 and very particularly preferably less than 30 g / m 2 and / or the nonwoven fabric preferably has a thickness of from 0.1 to 1.0 mm, particularly from 0.15 to 0.8 mm, preferably from 0.2 to 0.65 mm, particularly preferably from 0.25 to 0.55 mm. The basis weight of the nonwoven fabric is from 10 g / m 2 to 80 g / m 2 particularly from 15 g / m 2 to 60 g / m 2 preferably from 15 g / m 2 to 30 g / m 2It is highly particularly preferred that it is up to this point. Further, it is within the scope of the present invention that the nonwoven fabric has a thickness h of at least 0.3 mm, particularly at least 0.45 mm, especially at least 0.55 mm, preferably at least 0.6 mm, particularly preferably at least 0.625 mm. At this time, the thickness h particularly means the maximum thickness or total thickness of the nonwoven fabric in a direction transverse to, particularly perpendicular or essentially perpendicular to, its flat extension in the non-embossed area of the nonwoven fabric. At this time, the thickness or total thickness h of the nonwoven fabric is measured according to the method of WRT120.6(05)-Option A.

[0051] It is within the scope of the present invention that the nonwoven fabric has a Martindale abrasion resistance of at least class 2, especially class 1 according to Martindale, and / or the nonwoven fabric has a maximum bending stiffness using a cantilever of at most 100 mm, especially at most 90 mm, preferably at most 80 mm, particularly preferably at most 70 mm, very particularly preferably at most 65 mm. This embodiment is based on the finding that the nonwoven fabric features very satisfactory abrasion resistance and / or the nonwoven fabric also has advantageously low bending stiffness and in particular improved drapability compared to known means or nonwovens. This advantageously contributes to the solution of the above technical problem, particularly to the optimum compromise of nonwoven fabric properties. The abrasion resistance of the nonwoven fabric is determined within the scope of the present invention particularly using a Martindale abrasion tester according to the following test method.

[0052] As the testing machine, in particular, the machine called "SDL Atlas M235 Martindale Tester" is used. The procedure for determining abrasion resistance is based on WSP20.5(05) in particular, and at this time, in particular, the following deviations from WSP20.5(05) are defined: The surfaces (upper / lower) are tested separately; At least 10 tests, preferably at least 20 tests, are carried out for one sample and one surface. At this time, the test pieces are evenly obtained from the surface of the sample, and the final result is the arithmetic mean value. The test pieces should be obtained from representative positions, not just from the edges for example, because the deviation as a test or result should only be affected by typical (local) variations, not by macroscopic deviations such as poor process control; The test sample to be tested is stretched on a standard felt and attached to the lower holder; As the moving upper friction surface, the same non-woven fabric is used so that the test sides face each other, and this piece is fixed together with a PU foam plastic patch (for example, manufactured by SDL Atlas); A pressing force of 9 kPa; 32 cycles, that is, two complete loops of the Lissajous figure; After each test, the pair (test piece and upper friction surface) is exchanged; The sample is evaluated on a scale from 1 to 5, where 1 is the best score. For example, if the average value is 1 on the upper side and 3 on the lower side, the sample is evaluated as 1 overall. When only evaluating the changes in the non-woven fabric, if this non-woven fabric has similar defects beforehand, these can be overlooked. This means, for example, fiber tufts (groups or bundles of fibers on the surface). If the test piece clearly shows these defects from the beginning, that test piece should preferably be excluded if there is doubt.

[0053] Rating 1: When viewed from above, there is virtually no change. There may be some signs of loosening on the surface, but the filaments should only be loose and should not form large or long agglomerates. When viewed from the side, the fuzz height of the loose filaments should not exceed 5 mm. Individual filaments or a plurality of filaments may gather to form small globules with a diameter of less than 2 mm.

[0054] Score 2: In addition to the above damage pattern (Score 1): The filaments are loose and intertwined with adjacent filaments to form long aggregates. These groups of filaments are referred to as "tufts" or "strings or bundles". These tufts range in length from 5 to 40 mm and are attached to the substrate at least every 10 mm in length. One tuft has a maximum height of 5 mm (extending 5 mm from the surface) and a maximum width of 2 mm.

[0055] Score 3: The above-mentioned "tuft" is no longer attached to the substrate along its length, and if there are attachment points, they are more than 10 mm apart from each other, or in this case, the tuft is attached to the sample only at the starting and ending points. This tuft can be lifted and moved, for example, using a needle.

[0056] Score 4: The tufts are joined to adjacent tufts to form a network. "Spider web" Score 5: The sample is further damaged and the formation of the first hole has occurred.

[0057] The bending stiffness of the nonwoven fabric is determined within the framework of the present invention, in particular, according to the method of "WSP90.1(05) Standard Test Method for Stiffness of Nonwoven: Fabrics Using the Cantilever Test".

[0058] It is within the scope of the present invention that the strength of the non-woven fabric in the machine direction (MD direction) is at least 8 N / 5 cm, particularly at least 10 N / 5 cm, especially at least 15 N / 5 cm, preferably at least 17.5 N / 5 cm, particularly preferably at least 20 N / 5 cm, and very particularly preferably at least 22.5 N / 5 cm. In the context of the present invention, the machine direction (MD direction) particularly means the conveyance direction F of the non-woven fabric on the deposition device. The strength of the non-woven fabric in the machine direction is determined, in the context of the present invention, particularly by the following method: "Determination of Tensile Strength (Edana 20.2 - 89 standard)": unit of N / 5 cm; sample width of 50 mm; grip length of 100 mm; test speed of 200 mm / min.

[0059] According to a preferred embodiment of the present invention, the non-woven fabric is formed as a non-woven fabric laminate composed of at least two non-woven webs or non-woven layers.

[0060] The present invention is based on the finding that by using the method according to the present invention, it is possible to provide a non-woven fabric featuring an optimal compromise between advantageous mechanical properties, sufficient thickness or volume, low stiffness or good drapability, and advantageous abrasion resistance. By means of the combination according to the present invention of fixation using at least one calendar roller, in particular at least one calendar or pair of calendar rollers comprising this calendar roller, and fixation using at least one thermal-fluid main fixation device, an optimal compromise of these properties can be achieved. It should be emphasized that these non-woven fabric properties can be achieved very reliably and yet by relatively simple means within the framework of the method according to the present invention. Furthermore, the method according to the present invention is characterized by optimal flexibility. According to a preferred embodiment, said non-woven fabric properties can be further optimized by the temperature relationship between the calendar roller or calendar and the thermal-fluid main fixation device, as well as by the components of the fibers or filaments and by the configuration of the fibers or filaments. When an embossing pattern consisting of a plurality of embossings is introduced into the non-woven fabric, and in a very particularly preferred embodiment when an embossing pattern consisting of a plurality of embossings with a relatively small embossing area is introduced into the non-woven fabric, it is furthermore possible to almost completely avoid the influence on the visual properties of the resulting non-woven fabric, wherein the non-woven fabric nevertheless has the advantageous mechanical properties resulting from such a calendaring or embossing process. In summary, it can be confirmed that within the framework of the present invention, the optimal compromise of the non-woven fabric properties described above can be achieved. Due to the flexibility of the method, the non-woven fabric properties can be further optimized according to a preferred embodiment of the method according to the present invention, for example with regard to the temperature used in the fixation step or with regard to the design of the fibers or filaments.

Example

[0061] Hereinafter, the present invention will be described in more detail based on examples.

[0062] In the following three embodiments, only the fixing or main fixing of the nonwoven fabric is different. At this time, for all three embodiments (Examples 1 to 3), the following parameters and methods are first applied: This is a spunbond nonwoven fabric composed of two spunbond nonwoven webs or nonwoven layers spun using a first spinning beam and a second spinning beam. The basis weight of the resulting nonwoven fabric was 20 g / m 2 each. The deposition screen belt speed was 315 m / min. The fibers were each manufactured or deposited as crimped endless filaments in the form of bicomponent filaments. At this time, the filaments of the first spinning beam had an eccentric core-sheath structure with a D-shaped core, and the filaments of the second spinning beam had a side-by-side structure. As the first component for the filaments of the first spinning beam, polyethylene was used (DOW Aspun6850 + 2 wt% white coloring additive). As the second component for the filaments of the second spinning beam, polypropylene was used (Exxon PP3155 + 5 wt% Borealis HL712FB + 1 wt% lubricant additive). The mass ratio of the first component to the second component was 50:50. As the first component for the filaments of the second spinning beam, polyethylene was used (DOW Aspun6834 + 2 wt% white coloring additive). As the second component for the filaments of the second spinning beam, polypropylene was used (Exxon PP3155 + 1 wt% Borealis HL712FB + 1 wt% lubricant additive). The mass ratio of the first component to the second component was 40:60. The throughput of the first beam was 145 kg / h / m, and the throughput of the second beam was 180 kg / h / m.

[0063] After the first beam, pre-fixing using a hot air knife (650 m 3 / h / m; 145 °C, 90 mm total length) and pre-fixing using a hot air field (1.5 m / s; 135 °C, 900 mm total length) were performed. After the second beam, a hot air knife (625 m 3Pre - fixation was carried out using / h / m; (145 °C, total length 90 mm), and fixation or main fixation was carried out using a hot - air field with three different consecutive temperature zones (each with a total length of 1200 mm) operating at different temperatures in different examples as described below. Then, when described, calendaring was carried out. The filaments of the first non - woven web or non - woven layer had an average fineness of 1.3. The filaments of the second non - woven web or non - woven layer had an average fineness of 2.0.

[0064] For the fixation or main fixation of the non - woven fabrics of the examples (Examples 1 - 3), first, the following common conditions and procedures apply: The calendar had a total pressure - applying surface of embossing elements of 4% and 41.7 Fig / cm 2 and an embossing element with a circular pressure - applying surface; the pressure - applying surface of the embossing element had a diameter of 0.35 mm, and thus had a pressure - applying surface of approximately 0.096 mm 2 ; the distance between the embossing elements, determined in the same way as the minimum distance d between the two embossings described above, was 1.2 mm; the calendar was equipped with an upper calendar roller with embossing elements and a lower calendar roller with a smooth surface. In the transport direction F of the non - woven fabric, after the calendar, a hot - air - type main fixation device in the form of an omega oven with a diameter of 1414 mm and an effective flow length of 3500 mm was arranged (air velocity 0.8 m / s). The cantilever values and Martindale values described below were measured as described above: "Upper" means, in Martindale data, the side facing the calendar roller with embossing elements, and "lower" means the side facing the deposition screen belt.

[0065] Example 1: Fixation or main fixation using the hot - air field after the second spinning beam: Three different consecutive temperature zones: 120 °C / 130 °C / 80 °C; Surface temperature of the calendar: 129 °C on the calendar roller with embossing elements and 123 °C on the smoothing roller; Linear load of the calendar: 30 N / min; Temperature of the omega oven: 80 °C.

[0066] A non-woven fabric was produced with a strength of 20.7 / 5 cm in the machine direction (MD direction), a thickness of 0.45 mm, and a cantilever of 65 mm, and abrasion resistance of class 1 (upper side) / class 1 (lower side) according to Martindale. Therefore, a product was produced that features particularly very advantageous abrasion resistance, a very advantageous low cantilever value, sufficient strength, and a satisfactory thickness.

[0067] Example 2: Fixing or main fixing using a hot air field after the second spinning beam: Three different consecutive temperature zones: 120 °C / 130 °C / 130 °C; Calender surface temperature: 121 °C for the calender roller with embossing elements and 127 °C for the smoothing roller; Calender linear load: 30 N / min; Omega oven temperature: 128 °C.

[0068] A non-woven fabric was produced with a strength of 26.6 N / 5 cm in the machine direction (MD direction), a thickness of 0.39 mm, and a cantilever of 77 mm, and abrasion resistance of class 1 (upper side) / class 1 (lower side) according to Martindale. Therefore, a product was produced that features very advantageous abrasion resistance, advantageously low cantilever value, very advantageous strength, and sufficient thickness.

[0069] Example 3 (not according to the state of the art or the present invention): Fixing or main fixing using a hot air field after the second spinning beam: Three different consecutive temperature zones: 120 °C / 130 °C / 130 °C; Calender: open system, i.e., no contact or fixing with the non-woven fabric to the calender; Omega oven temperature: 138 °C; Therefore, no combined fixing with the calender.

[0070] A non-woven fabric was produced with a strength of 21.3 N / 5 cm in the machine direction (MD direction), a thickness of 0.53 mm, and a cantilever of 105 mm, and abrasion resistance of class 2.5 (upper side) / class 1 (lower side) according to Martindale. Therefore, a product was produced that features particularly, on one non-woven fabric surface, disadvantageous abrasion resistance, disadvantageous cantilever value, sufficient strength, and advantageous thickness.

[0071] The present invention will be described in more detail below based on the drawings showing only one embodiment.

Brief Description of the Drawings

[0072]

Figure 1

Figure 2

Figure 3

Figure 4

[0073] FIG. 1 shows an apparatus 14 according to the present invention for the production of a non-woven fabric 1 having two non-woven webs 2, 2' made of crimped endless filaments 10 for carrying out the method according to the present invention. This apparatus comprises, inter alia and in this embodiment, two spinning beams 3, 3', which are, preferably and in this embodiment, each designed to produce spunbond non-woven webs 2, 2' from crimped endless filaments 10 in the form of bicomponent filaments. Further, correspondingly, in a preferred embodiment, there is an endless circulating deposition screen belt 4 for depositing the endless filaments 10 to form the non-woven webs 2, 2'. The apparatus 14 has, preferably and in this embodiment, a calendar roller 5 for introducing an embossing pattern 11 (FIGS. 3 and 4) consisting of a plurality of embosses 12 not connected to each other into the non-woven fabric 1. This calendar roller 5 is, preferably and in this embodiment, part of a calendar 6 consisting of a calendar roller pair 5, 7. Preferably and in this embodiment, the calendar roller 5 of the calendar 6 has a complementary embossing pattern 15 consisting of embossing elements 16, which are, inter alia, each from 0.05 to 0.6 mm 2It has a pressing surface 17 up to this point. At this time, the pressing surface 17 particularly means the surface of the embossing element 16 of the calendar roller 5 provided for generating the embossing surface 13 of the emboss 12 of the nonwoven fabric 1. Preferably and in the embodiment based on FIG. 1, the embossing element 16 of the calendar roller 5 is formed in the shape of a frustum of a cone, and the pressing surface 17 corresponds to the upper surface of this frustum of a cone. The other or further calendar roller 7 of the calendar 6 is preferably and in this embodiment formed as a smoothing roller 7 having a smooth outer surface.

[0074] According to a particularly preferred embodiment and in the embodiment based on FIG. 1, the device 14 comprises a hot air type main fixing device 8, which is arranged particularly behind the calendar roller 5 or behind the calendar 6 in the conveying direction F of the nonwoven fabric. Preferably and in this embodiment, the hot air type main fixing device 8 is configured as a hot air furnace. Purposefully and in this embodiment, further, the device 14 comprises two pre-fixing devices in the form of hot air type pre-fixing devices 9, 9'. The hot air type pre-fixing devices 9, 9' are arranged particularly in front of the calendar roller 5 or in front of the calendar 6 respectively in the conveying direction F of the nonwoven fabric 1. Particularly and in the embodiment based on FIG. 1, the hot air type pre-fixing devices 9, 9' are arranged respectively immediately behind the spinning beams 3, 3' for pre-fixing the deposited nonwoven webs 2, 2'. The first hot air type pre-fixing device 9 is arranged preferably immediately behind the first spinning beam 3 in the conveying direction F of the nonwoven fabric 1, and then there is a second spinning beam 3', and immediately behind that, the second hot air type pre-fixing device 9' is arranged. The hot air type pre-fixing devices 9, 9' are preferably designed as hot air knives and / or hot air fields.

[0075] Within the framework of the method according to the invention and in the embodiment based on FIG. 1, from the first spinning beam 3, first a non-woven web 2 is produced from the crimped endless filaments 10 and deposited on the deposition screen belt 4. Subsequently, the non-woven web 2 is pre-fixed, preferably and in this embodiment, using a hot air pre-fixing device 9. Thereafter, expediently, a second non-woven web 2' made from the crimped endless filaments 10 is produced from the second spinning beam 3' and deposited on the first non-woven web 2. Subsequently, the second non-woven web 2' or the assembly of the first non-woven web 2 and the second non-woven web 2' is pre-fixed using the second hot air pre-fixing device 9', and then, inter alia, peeled off from the deposition screen belt 4 and fed to a calendar 6 equipped with calendar rollers 5. In particular and in this embodiment, using the calendar rollers 5 of the calendar 6, an embossed pattern 11 consisting of a plurality of embossments 12 is introduced into the non-woven fabric 1, at which time the non-woven fabric 1 is expediently fixed. Subsequently, preferably, the fixing or main fixing of the non-woven fabric 1 is carried out using at least one hot air main fixing device 8.

[0076] FIG. 2 shows a partial basic structure of an apparatus 14 according to the invention for producing a non-woven web 2 according to the spunbond method, comprising a spinneret or spinning beam 3 for spinning the endless filaments 10 for the spunbond non-woven web 2 made from the endless filaments 10. The endless filaments 10 spun from the spinneret or spinning beam 3 are introduced into a cooling device 18 equipped with a cooling chamber 19. In particular and in this embodiment, on two opposite sides of the cooling chamber 19, air supply cabins 20, 21 arranged one above the other are arranged. From these air supply cabins 20, 21 arranged one above the other, preferably, air of different temperatures is introduced into the cooling chamber 19.

[0077] As recommended and in this example, in the flow direction of the filament, a stretching device 22 for stretching the endless filament 10 is arranged behind the cooling device 18. Expediently and in this example, the stretching device 22 comprises an intermediate channel 23 which connects the cooling device 18 to the stretching shaft 24 of the stretching device 22. Preferably and in this example, the connecting mechanism consisting of the cooling device 18, the intermediate channel 23 and the stretching shaft 24 is configured as a closed connecting mechanism, and apart from the supply of cooling air into the cooling device 18, no further external air supply to this connecting mechanism takes place.

[0078] Expediently and in this example, in the flow direction of the filament, a diffuser 25 is connected to the stretching device 22 through which the endless filament 10 is guided. After passing through the diffuser 25, the endless filament 10 is deposited, inter alia and in this example, on a deposition device configured as a deposition screen belt 4. The deposition screen belt 4 is preferably and in this example configured as an endless circulating deposition screen belt 4. It is within the scope of the invention that the deposition screen belt 4 is air-permeable, such that suction of process air from below through the deposition screen belt 4 is possible.

[0079] Figs. 3 and 4 show the nonwoven fabric 1 of the present invention provided with at least one nonwoven web 2 made of fibers. In this embodiment, the nonwoven fabric 1 has two nonwoven webs 2, 2' made of endless filaments 10, and is particularly configured as a nonwoven laminate. The endless filaments 10 may be, among other things and in this embodiment, crimped endless filaments 10. Preferably and in this embodiment, the nonwoven fabric 1 is a spunbond nonwoven fabric having two spunbond nonwoven webs 2, 2' made of crimped endless filaments 10. The crimped endless filaments 10 may, in this embodiment, be bicomponent filaments having an eccentric core-sheath configuration, where the sheath of the endless filament 10 preferably consists of or consists essentially of polyethylene, and the core of the endless filament 10 consists of or consists essentially of, in particular, at least one polyester and / or polypropylene.

[0080] Furthermore, Figs. 3 and 4 show that the nonwoven fabric 1 has an embossing pattern 11, where the embossing pattern 11 consists of a plurality of embossings 12 that are not connected to each other. The embossing pattern 11 is preferably and in this embodiment a regular embossing pattern 11, and its individual embossings 12 are arranged, among other things and in this embodiment, distributed on the nonwoven fabric 1 at regular intervals.

[0081] Within the framework of the present invention and in this embodiment, the embossings 12 are each from 0.05 to 0.6 mm 2It has an embossed surface 13 up to. The embossed surface 13 of the emboss 12, within the framework of the present invention and in this embodiment, in particular, means the embossed surface of the emboss 12. At this time, when determining the area of the embossed surface 13, material protrusions or material bulges that are formed during the pressing or embossing process and at least partially surround the emboss 12 are not part of the embossed surface 13 of the emboss 12. This can be seen, in particular, in the hatched depiction in FIG. 4. More preferably and in this embodiment, the embossed surfaces 13 of the individual embosses 12 of the embossing pattern 11 are of the same size or essentially of the same size. In particular and in this embodiment according to these figures, the embossed surface 13 of the emboss 12 has a dot-shaped or circular geometry when viewed from above. Very particularly preferably and in this embodiment, the embossing pattern 11 has embosses 12 of the same or the same size, or essentially the same or the same size, and the embosses 12 of the same geometry or essentially the same geometry are uniformly distributed.

[0082] Within the framework of the present invention, the minimum distance d between two embosses 12 of the embossing pattern 11 is from 0.6 to 3.0 mm respectively. At this time, the minimum distance d between two embosses 12, in particular, means the minimum distance d between two directly adjacent embosses 12 of the embossing pattern 11, that is, preferably, the minimum distance d between one emboss 12 and the emboss 12 closest to it in the embossing pattern 11. Further, the minimum distance d between two embosses 12, in particular, means the minimum distance d between the respective emboss boundaries of the two embosses 12, that is, the minimum distance between these two embosses 12 along the surface of the non-woven fabric 1 that is not embossed and exists between the two embosses 12.

[0083] For the purpose, the thickness h of the nonwoven fabric 1 is from 0.15 to 0.75 mm. In the embodiments based on these drawings, the thickness h of the nonwoven fabric 1 can be about 0.4 mm. At this time, the thickness h means the maximum thickness or the total thickness of the nonwoven fabric 1 in a direction transverse to, in particular perpendicular or essentially perpendicular to, the flat elongation in the unembossed area of the nonwoven fabric 1. This can be seen particularly in FIG. 4.

Claims

1. A method for manufacturing a nonwoven fabric (1) having at least one nonwoven web (2) made of fibers, wherein the fibers are manufactured using at least one fiber manufacturing device, in particular using at least one spinning beam (3), and the fibers are then deposited onto at least one deposition device, in particular onto a deposition screen belt (4), to form a nonwoven web (2), and the nonwoven web (2) or the nonwoven fabric (1) is fixed using at least one calendar roller (5), in particular using at least one calendar (6) or calendar roller pair (5, 7) comprising this calendar roller (5), and further, the nonwoven fabric (1) is fixed or primarily fixed using at least one thermal fluid type primary fixing device, in particular using at least one hot air type primary fixing device (8).

2. The method according to claim 1, wherein the nonwoven fabric (1) is peeled from the deposition device before the fixing using the at least one calendar roller (5) and / or before the fixing or primary fixing using the at least one thermal fluid type primary fixing device.

3. The fixing of the nonwoven fabric (1) using the at least one calendar roller (5), in particular using at least one calendar (6) or calendar roller pair (5, 7) comprising this calendar roller (5), is carried out before or after the fixing or primary fixing of the nonwoven fabric (1) using the at least one thermal fluid type primary fixing device, in particular using the at least one hot air type primary fixing device (8), according to the method of claim 1 or 2.

4. After the deposition of the nonwoven fabric (1) onto the deposition device and before the fixing or primary fixing, the nonwoven fabric (1) is first pre-fixed using at least one pre-fixing device, in particular a pre-fixing device arranged immediately after the at least one fiber manufacturing device or the at least one spinning beam (3), in particular using at least one thermal fluid type pre-fixing device, preferably using at least one hot air type pre-fixing device (9), and the at least one thermal fluid type pre-fixing device or hot air type pre-fixing device (9) is particularly preferably configured as a hot air knife and / or a hot air field. The method according to any one of claims 1 to 3.

5. The method according to any one of claims 1 to 4, wherein the at least one heat-fluid main fixing device or the at least one hot-air main fixing device (8) is preferably configured as a hot-blast stove, particularly preferably as an omega oven and / or as a multi-drum oven and / or as a single-belt oven and / or as a double-belt oven.

6. The method according to any one of claims 1 to 5, wherein the residence time of the non-woven fabric (1) in the heat-fluid main fixing device is from 0.4 seconds to 25 seconds, preferably from 1 second to 15 seconds, and / or the fluid velocity of the fluid in the heat-fluid main fixing device is from 0.4 to 3 m / s, preferably from 0.5 to 2 m / s.

7. The method according to any one of claims 1 to 6, wherein the surface temperature T1 of the at least one calendar roller (5), in particular of the at least one calendar (7) or calendar roller pair (5, 7) comprising this calendar roller (5), is higher than the fluid temperature T2 of the at least one heat-fluid main fixing device, in particular from 0.5 °C to 10 °C, preferably from 1 °C to 5 °C higher, or lower than the fluid temperature T2 of the at least one heat-fluid main fixing device, or the same as or essentially the same as the fluid temperature T2 of the at least one heat-fluid main fixing device.

8. The method according to any one of claims 1 to 7, wherein the fibers of the at least one non-woven web (2) are produced or spun as endless filaments (10), in particular as crimped endless filaments (10), wherein the endless filaments (10) or the crimped endless filaments (10) are particularly preferably produced or spun as multi-component filaments, particularly preferably as bicomponent filaments.

9. The multi-component filament or bicomponent filament comprises a first component, in particular a first low melting point component, which consists of or consists essentially of at least one thermoplastic, in particular at least one polyolefin, especially polyethylene and / or polypropylene, and / or the multi-component filament or bicomponent filament comprises a second or further component, in particular a second or further higher melting point component, which consists of or consists essentially of at least one thermoplastic, in particular at least one polyester and / or polypropylene, according to the method of claim 8.

10. The endless filament (10), in particular the crimped endless filament (10), is manufactured or spun as a multi-component filament or bicomponent filament having a side-by-side configuration and / or a core-sheath configuration, in particular an eccentric core-sheath configuration, and preferably, the first component is the sheath component and the second component is the core component, according to the method of claim 8 or 9.

11. The surface temperature T1 of the at least one calendar roller (5), in particular of at least one calendar (7) or calendar roller pair (5, 7) comprising this calendar roller (5), and / or the fluid temperature T2 of the at least one thermal fluid type main fixing device satisfies the following conditions with respect to the melting temperature Tm of the first component, in particular the first low melting point component, of the multi-component filament or bicomponent filament, that is: (Tm - 15 °C) < T1 and / or T2 < (Tm + 15 °C), in particular (Tm - 10 °C) < T1 and / or T2 < (Tm + 10 °C), preferably (Tm - 8 °C) < T1 and / or T2 < (Tm + 8 °C), particularly preferably (Tm - 7 °C) < T1 and / or T2 < (Tm + 7 °C), very particularly preferably (Tm - 6 °C) < T1 and / or T2 < (Tm + 6 °C), for example (Tm - 5 °C) < T1 and / or T2 < (Tm + 5 °C), according to the method of claim 9 or 10.

12. Using the at least one calendar roller (7), an embossing pattern (11) consisting of a plurality of (especially not connected to each other) embossings (12) is introduced into the nonwoven fabric (1), wherein the embossings (12) each have an embossed surface (13) of from 0.05 to 0.6 mm ２ up to, especially from 0.06 to 0.4 mm ２ up to, preferably from 0.07 to 0.25 mm ２ up to, particularly preferably from 0.08 to 0.15 mm ２ up to, very particularly preferably from 0.09 to 0.12 mm ２ A method according to any one of claims 1 to 11, having an embossed surface (13) of up to.

13. The method according to claim 12, wherein the minimum distance d between two embosses (12) of the emboss pattern (11) is from 0.6 to 3.0 mm, particularly from 0.8 to 2.5 mm, preferably from 0.9 to 2.0 mm, particularly preferably from 0.95 to 1.8 mm, and very particularly preferably from 1.0 to 1.5 mm, and the emboss pattern (11) is generated on this condition.

14. The method according to claim 12 or 13, wherein the ratio of the total embossed surface of the emboss pattern (11) to the entire surface of the nonwoven fabric (1) is from 2 to 15%, particularly from 2.5 to 12%, preferably from 3 to 8%, particularly preferably from 3.5 to 6%, and very particularly preferably from 3.8 to 5.2%, and the emboss pattern (11) is generated on this condition.

15. A nonwoven fabric (1) having at least two nonwoven webs (2, 2') made of fibers is produced. For this purpose, first fibers are produced from at least one first fiber production device, particularly from at least one first spinning beam (3), and then deposited on a deposition device, particularly on a deposition screen belt (4), to form a nonwoven web (2). Second fibers are produced from at least one second fiber production device, particularly from at least one second spinning beam (3'), and then deposited on the first nonwoven web (2) to form a second nonwoven web (2'). An assembly composed of the at least two nonwoven webs (2, 2') or the nonwoven fabric (1) is fixed using at least one calendar roller (5), particularly using at least one calendar (6) or a calendar roller pair (5, 7) including this calendar roller (5). Further, the nonwoven fabric (1) is fixed or primarily fixed using at least one hot-fluid type primary fixing device, particularly using at least one hot-air type primary fixing device (8). The method according to any one of claims 1 to 14.

16. An apparatus for manufacturing a nonwoven fabric (1) having at least one nonwoven web (2) made of fibers, in particular for implementing the method according to any one of claims 1 to 15, wherein the apparatus (14) comprises at least one fiber manufacturing device, in particular at least one spinning beam (3), and at least one deposition device for depositing the fibers to form the nonwoven web (2), in particular at least one deposition screen belt (4), and further, at least one calendar roller (5), in particular a calendar (6) or a pair of calendar rollers (5, 7) comprising this calendar roller (5) is provided for fixing the nonwoven fabric (1), and in addition, at least one thermal fluid type main fixing device, in particular at least one hot air type main fixing device (8), is present for fixing or main fixing the nonwoven fabric, said apparatus.

17. The apparatus according to claim 16, wherein the at least one calendar roller (5), in particular the calendar (6) or the pair of calendar rollers (5, 7) comprising this calendar roller (5), is arranged in front of or behind the at least one thermal fluid type main fixing device in the conveying direction F of the nonwoven fabric (1).

18. The at least one calendar roller (5) has a complementary embossed pattern (15) consisting of embossing elements (16) for introducing an embossed pattern (11) consisting of a plurality of embosses (12) into the nonwoven fabric (1), wherein the embossing elements (16) each have a pressing surface (17) of from 0.05 to 0.6 mm ２ up to, preferably from 0.06 to 0.4 mm ２ up to, more preferably from 0.07 to 0.25 mm ２ up to, particularly preferably from 0.08 to 0.15 mm ２ up to, very particularly preferably from 0.09 to 0.12 mm ２ The apparatus according to claim 16 or 17, having a pressing surface (17) of up to

19. A nonwoven fabric manufactured according to the method according to any one of claims 1 to 15 and / or using the apparatus according to any one of claims 16 to 18.

20. The nonwoven fabric (1) has an embossed pattern (11) composed of a plurality of (especially, non-connected to each other) embosses (12), and in this case, the embosses (12) are each, especially, from 0.05 to 0.6 mm ２ up to, preferably from 0.06 to 0.4 mm ２ up to, more preferably from 0.07 to 0.25 mm ２ up to, particularly preferably from 0.08 to 0.15 mm ２ up to, very particularly preferably from 0.09 to 0.12 mm ２ up to, and have an embossed surface (13) and / or the embossed surface (13) of the emboss (12) has, when viewed from above, at least one geometric shape selected from the group of "dot-shaped or circular, elliptical, square, rectangular, rhombic, polygonal, linear, wavy", the nonwoven fabric according to claim 19.

21. The nonwoven fabric (1) has a basis weight of less than 200 g / m ２ 2, especially less than 150 g / m ２ 2, particularly less than 100 g / m ２ 2, preferably less than 75 g / m ２ 2, particularly preferably less than 50 g / m ２ 2, very particularly preferably less than 30 g / m ２ 2, and / or the nonwoven fabric (1) has a thickness h of from 0.1 to 1.0 mm, especially from 0.15 to 0.8 mm, preferably from 0.2 to 0.65 mm, particularly preferably from 0.25 to 0.55 mm, the nonwoven fabric according to claim 20.

22. The nonwoven fabric (1) has a wear resistance of at least class 2 according to Martindale, in particular a wear resistance of class 1 according to Martindale, and / or the nonwoven fabric (1) has a maximum bending rigidity using a cantilever of at most 100 mm, in particular at most 90 mm, preferably at most 80 mm, particularly preferably at most 70 mm, very particularly preferably at most 65 mm, the nonwoven fabric according to claim 20 or 21.

23. The nonwoven fabric according to any one of claims 20 to 22, wherein the nonwoven fabric (1) is formed as a nonwoven laminate comprising at least two nonwoven webs (2, 2') or nonwoven layers.

Images