EP3604652B1 - Nonwoven fabric, use of the nonwoven fabric and wipe, dryer cloth and face mask containing the nonwoven fabric - Google Patents

Description

technical field

The invention relates to a nonwoven fabric with a network of shaped bodies, the nonwoven fabric having a specific opacity of greater than or equal to 1.0%·m ² /g in the dry state. In addition, the invention relates to uses of the nonwoven and a wipe, a dryer towel and a face mask containing the nonwoven.

State of the art

Nonwovens (also known as nonwovens or non-woven textiles) are used in a wide range of applications. The unique properties and low manufacturing costs make them an ideal substrate for disposable or disposable products in hygiene applications such as wipers, wet wipes, face masks, diapers and others. Especially in the area of wiper applications, customers have requirements in terms of high opacity, sufficient mechanical strength, flexibility, thickness and high water absorption of the products. In particular, high opacity is of great importance to the end customer, as nonwoven products with too low opacity tend to be associated with low tear strength and low reliability. At the same time, however, the desire for products with a low basis weight is constantly increasing. A high level of opacity can enable a further reduction in basis weight and still convey the feeling of tear resistance and reliability to the end customer.

Although nonwovens with a high basis weight are usually associated with high opacity, the production of nonwovens with a low basis weight, particularly in the range below about 35 g/m ² , and at the same time high opacity poses major challenges for manufacturers.

Simple hydroentangled nonwovens (as in the EP 0473325 A1 known) can only be produced with great effort in low basis weights and then have a highly irregular structure and thus also opacity. Without appropriate modifications and additives, these often cannot achieve the necessary or desired opacity with low basis weights.

So it is about from the prior art ( U.S. 2017/0360622 A1 , CN 107460787A , CN 104556966A ) known to increase the opacity of a nonwoven by adding a matting agent such as titanium dioxide or zinc oxide. However, such delustrants are expensive and severely weaken the strength and flexibility of the fibers. In addition, these substances require an increased process engineering effort in order to be able to be incorporated into the fibers.

Next are, for example, from the prior art ( US 3666545A , WO 2010/028238 A1 ) Spunbonded known, which are made of thermoplastic synthetic polymers in a meltblown or spunbond process. However, nonwovens having such a spunbonded nonwoven require a multi-layer structure in order to be able to meet the requirements for strength and stability. The individual layers of different nonwovens are glued or fused together or provided with an additional coating in order to achieve the desired opacity of the nonwoven. However, such nonwovens generally have a low water absorption capacity due to the synthetic polymer filaments and low flexibility due to the multi-layer or coated layer structure. In addition, nonwoven fabrics comprising synthetic polymers are not biodegradable and their use in disposable or single-use products should be avoided.

Another prior art ( WO 2006/133037 A1 , WO 2004/063434 A1 ) known way to increase the opacity in nonwovens is the use of cross-section-modified fibers. For example, it is known to extrude the fibers through a specially shaped nozzle and thus to obtain fibers with a modified cross section, such as hollow fibers. Although fibers of this type have increased opacity compared to fibers with a solid, rounded cross section, they are complicated in terms of process technology and are therefore expensive to produce. In addition, when synthetic polymers are used, such fibers exhibit reduced water absorption.

The nonwoven fabrics according to the invention can be produced according to a method for the direct production of nonwoven fabrics from a cellulose-containing spinning solution.

Such methods are, for example, from the prior art ( WO 98/26122 A1 , WO 99/47733 A1 , WO 98/07911 A1 , WO 97/01660 A1 , WO 99/64649 A1 , WO 05/106085 A1 , EP 1 358 369 A1 , and EP 2 013 390 A1 , US2005/056956 ) known.

The preparation and extrusion of the spinning solution in such a process is preferably carried out using a direct dissolving process such as the lyocell process. Here, cellulose is directly dissolved in an aqueous solution of an amine oxide (preferably NMMO - N-methylmorpholine-N-oxide) and formed into a spinnable spinning solution. The spinning solution is then extruded through suitable spinnerets and the cellulose dissolved in the extruded spinning solution is precipitated with a coagulant to form shaped bodies. In the case of an amine oxide, water or a mixture of water and amine oxide is particularly suitable as a coagulant. The production of such spinning solutions by the Lyocell process for the production of nonwovens is, for example, from WO 98/26122 A1 , U.S. 7,067,444 B2 or US 8,012,565 B1 known.

Disclosure of Invention

The object of the invention is therefore to create a nonwoven fabric with a low weight per unit area, which is easy to produce and has a high specific opacity without special modifications.

The invention achieves the stated object in that the shaped bodies are regenerated cellulosic shaped bodies and are cohesively connected to one another via nodes to form the network, and the regenerated cellulosic shaped bodies comprise individual filament sections extending between nodes, which vary in diameter along their length and over at least 90% of their longitudinal extension have a diameter of less than or equal to 15 μm.

If the moldings are regenerated cellulosic moldings, biodegradable nonwovens can be created, which also in one simple and reliable methods can be produced inexpensively. If the shaped bodies are also bonded to one another via nodes to form the network, a particularly dimensionally stable fleece can be created, which enables high tear strength with a low basis weight. In addition, the opacity of the fleece can advantageously be greatly increased if the regenerated cellulosic shaped bodies comprise individual filament sections extending between nodes, which vary in diameter along their length and have a diameter of less than or equal to 15 μm over at least 90% of their length. The individual filament sections, which vary in diameter, can ensure a particularly high and advantageous light scattering due to their irregular surface and thus increase the opacity of the entire nonwoven fabric. As explained above, the individual filament sections with fine diameters make it possible to cover a particularly large area with a large number of filaments per area, which in turn is conducive to a homogeneous opacity of the nonwoven fabric. In addition, the very fine diameters of less than or equal to 15 µm make it possible to increase the volume and thus reduce the basis weight without sacrificing opacity. A nonwoven fabric with a low weight per unit area and a specific opacity of greater than or equal to 1.0%·m ² /g can thus be created.

It is also mentioned in this connection that the formation of individual individual filament sections with diameters greater than 15 μm is unavoidable due to the nature of the manufacturing process. However, such outliers in no way adversely affect the advantageous properties of the nonwovens according to the invention, as long as the individual filament sections have a diameter of less than or equal to 15 μm over at least 90% of their longitudinal extension. In further advantageous configurations of the invention, the individual filament sections can also have a diameter of less than or equal to 15 μm over at least 95% of their longitudinal extent.

In general, it is stated that a cohesive connection between the cellulose molecules of the regenerated cellulosic shaped bodies is understood as being a material connection between the shaped bodies in the nonwoven fabric. Such a connection can be achieved in particular by touching or bringing into contact molded bodies that have not yet fully coagulated (or extruded spinning solution) after its extrusion, with the cellulose molecules forming the material connection via cohesion.

In general, it is mentioned that the opacity of the nonwoven is understood to mean the degree of covering power or opacity. Such opacity is usually determined by measuring the light transmission of the non-woven fabric, where opacity [%] = 100% - light transmission [%].

Durch Bestimmung der spezifischen Opazität kann der Effekt der steigenden Opazität mit steigendem Flächengewicht normalisiert werden.The specific opacity of the nonwoven is defined as the opacity [%] normalized over the basis weight [g/m ² ] according to formula (1): $$\mathrm{specific}\mathrm{opacity}\left[\%\cdot {\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">m</figure-callout>}}^2/\mathrm{G}\right]=\mathrm{opacity}\left[\%\right]/\mathrm{basis\; weight}\left[\mathrm{G}/{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">m</figure-callout>}}^2\right].$$

By determining the specific opacity, the effect of increasing opacity with increasing basis weight can be normalized.

In general, it is also mentioned that the opacity of the nonwoven is determined in the dry state at a natural moisture content after conditioning at 23 °C (± 2 °C) and 50 % (± 5 %) relative humidity for 24 hours.

The properties of a nonwoven fabric of the aforementioned type can be further advantageously improved if the regenerated cellulosic shaped bodies comprise multifilament sections which extend between nodes and consist of a plurality of substantially parallel individual filament sections which are integrally bonded to one another. This is because the individual filaments connected to form the multifilament can thus contribute to stabilizing the nonwoven fabric and increasing its strength. If, in addition, the multifilament sections have a diameter of less than or equal to 100 μm over at least 90% of their longitudinal extent, it can further be ensured that the nonwoven fabric has a homogeneous appearance essentially without disturbing visible thickening. A network of shaped bodies can thus be created in the nonwoven fabric, which at the same time has thicker multifilament sections for structure and strength formation and thinner individual filament sections for increasing opacity. Such a network can have an essentially multimodal distribution of the shaped body diameter. The multifilament sections can be formed from 2 or more individual filaments after extrusion of the moldings. Here touch the not yet fully coagulated moldings and are permanently connected by cohesion. The multifilament sections are therefore not a bundle of individual filaments, but rather a chemically and physically inseparably connected unit.

If the regenerated cellulosic shaped bodies form an essentially endless network without visible filament ends, a nonwoven can be provided which has less abrasion and can also build up a better contact surface. For example, contact with the skin or with a surface can be improved.

The invention can also be characterized in a special way if the nonwoven is essentially free of matting agents and colorants. The use of customary matting agents, such as titanium dioxide or zinc oxide, requires very special processing conditions when producing the shaped bodies, since these agents are very difficult to disperse in a spinning solution due to their pronounced affinity for particle formation. In addition, the matting agent particles produce imperfections in the shaped bodies, which can lead to increased brittleness and reduced strength in the shaped body. This in turn poses a problem for the downstream processing industry, since the reduced strength or greater brittleness necessitate complex and cost-intensive processing steps. Furthermore, matting agents are expensive and have a negative impact on the cost-efficiency of nonwoven production. For this reason it is a further object of the invention to provide a nonwoven fabric with high opacity without the use of matting agents and other colorants. Surprisingly, it was found that nonwovens according to the invention with a network of regenerated cellulosic shaped bodies, having individual filament sections that have a diameter of less than or equal to 15 μm over at least 90% of their longitudinal extent, have a very high specific opacity without the use of matting agents. It is thus possible to provide nonwovens that are inexpensive and easy to produce.

According to the invention, the nonwoven can preferably consist essentially exclusively of cellulose. Such a non-woven fabric can be distinguished in particular from non-woven fabrics based on synthetic polymers by a good Characterize biodegradability, which is of particular importance for sustainable use in disposable or single-use products such as hygiene articles. In addition, purely cellulosic products have a significantly higher water absorption capacity than synthetic polymers, which is required in hygiene articles, for example. A nonwoven with a particularly small ecological footprint can be created in this way.

The aforementioned advantages can be further improved if the regenerated cellulosic shaped bodies are solution-spun cellulosic shaped bodies. Solution-spun shaped bodies are shaped bodies that are formed by extrusion of a spinning solution through spinnerets and subsequent coagulation, with the spinning solution being produced by directly dissolving cellulose in a solvent (without prior chemical conversion of the cellulose). The shaped bodies are preferably produced using a lyocell process, with NMMO (N-methylmorpholine-N-oxide) being used as the solvent. Solution-spun cellulosic shaped bodies advantageously have, among other things, increased strength compared to other regenerated cellulosic shaped bodies (such as viscose). In the case of lyocell moldings in particular, these advantages can be achieved using an environmentally friendly and cost-efficient process.

The properties of the nonwoven with regard to water absorption and strength can be further improved if the individual filament sections have a solid, in particular rounded, cross section.

Furthermore, it surprisingly turned out that a non-woven fabric with a very high specific opacity can be provided if the non-woven fabric is essentially free of binders or adhesives. Compared to nonwovens which are produced in layered structures which are connected to one another by means of binders or adhesives, the nonwovens according to the invention can dispense with the use of such substances. Especially with nonwovens that are used directly on the skin or in sensitive areas, it is of great importance that these nonwovens are free of substances that can potentially cause skin irritation or allergic reactions. Adhesives and binders, in particular, are known to cause such irritations or allergic reactions and should therefore be avoided in the event of skin contact. According to the invention so a skin-friendly nonwoven with a low risk of irritation and allergies can be created, which does not suffer any losses in terms of opacity.

If the nonwoven is also essentially free of copper and/or nickel, the previously mentioned advantages with regard to the low risk of irritation and allergies can be further improved, since even small residues of metals such as copper or nickel can, as is known, lead to incompatibilities. In particular, the nonwoven has a copper content of less than 5 ppm and/or a nickel content of less than 2 ppm in order to minimize the risk of irritation.

The specific opacity of the nonwoven can be further improved if the individual filament sections have a diameter of less than 10 μm, in particular less than or equal to 7 μm, over at least 90% of their longitudinal extent. Due to the very fine diameter of the individual filament sections of less than or equal to 10 μm, or in a further preferred embodiment of less than or equal to 7 μm, a particularly advantageous increase in volume and simultaneous reduction in basis weight can take place without the specific opacity of the nonwoven being reduced.

The aforementioned advantages can be further improved if the individual filament sections have an average diameter of greater than or equal to 1 μm and less than or equal to 8 μm. This creates a narrow diameter distribution of the individual filament sections, which on the one hand can guarantee a uniformly high specific opacity and on the other hand ensures high stability and strength in the nonwoven.

If the nonwoven has approximately the diameter of the individual filament sections preferred according to the invention, it can have a specific opacity of greater than or equal to 1.2%·m ² /g, or in a particularly advantageous embodiment of greater than or equal to 1.5%·m ² /g , exhibit. Nonwovens with such a high specific opacity can achieve excellent opacity even at very low basis weights.

The invention can be characterized particularly advantageously if the nonwoven fabric has a weight per unit area of less than or equal to 70 g/m ² . In a further advantageous embodiment, the nonwoven fabric has a basis weight of less equal to 35 g/m ² , particularly preferably less than or equal to 20 g/m ² . A particularly light and fine nonwoven fabric with excellent opacity can be created with it.

The non-woven fabric can also be distinguished advantageously if it contains substances or processing-facilitating agents in a content of max. 1% by weight, in particular max. 0.5% by weight. Such agents can be, for example, softening finishes, antistatic finishes, hydrophobic finishes or finishes which interact with lotions and thus facilitate the release of an active substance, for example. Such finishing agents can be selected, for example, from the group containing: fatty alcohol ether sulfates, phosphoric acid esters, alkyl ketene dimers, alkenyl succinic anhydride, aminopolysiloxane, ester quats, fatty acid polyglycol esters, aluminum sulfate, glycidyl ethers or substances of the same type or having the same effect.

• Wischtücher (bspw. für Babys, Küchen, Kosmetik, Hygiene, Reinigung, Politur, Staub, Industrie, Wischmops, etc.),
• Filter (bspw. Luftfilter, HVAC, Klimaanlage, Kaffeefilter, Teefilter, Filterbeutel, Speisefilter, Zigarettenfilter, Ölfilter, Filterkassetten, Staubsaugerbeutel, Staubfilter, Hydraulische Filter, Küchenfilter, HEVAC/HEPA/ULPA Filter, Atemschutzmasken, etc.),
• absorbierende Hygieneprodukte (wie etwa saugende Lagen, Windeln, Binden, Slipeinlagen, Inkontinenzprodukte, Tampons, Handtücher, Sanitärpads, spülbare Produkte, Einlagen, Stilleinlagen, Einweg-Unterwäsche, Trainingshosen, Abschminkpads, Waschlappen, etc.),
• medizinische Anwendungen (bspw. in Einweg-Kappen, -Kittel, -Masken und -Überschuhen, Wundpflege, steriler Verpackung, Coverstock, Verbandsmaterial, Einweg-Kleidung, Nasenstreifen, Wegwerf-Unterwäsche, Bettwäsche, transdermale Medikamentenabgabe, Leichentücher, Unterlagen, Behandlungspackungen, Wärmepackungen, Stomabeutel, Fixierbänder, Inkubatormatratzen, Matratzenabdeckungen, etc.),

• Geotextilien (etwa in Pflanzenschutzbezügen, Asphaltauflagen, Bodenstabilisierung, Imprägnierungslagen, Grubenauskleidungen, Pflanzdecken, Unkrautbekämpfungsgeweben, Gewächshaus-schattierung, etc.),
• Bekleidung (bspw. Einlagevliese, Kleidungsisolierung und -Schutz, Handtaschenbestandteile, Schuhkomponenten, Gürteleinlagen, industrielle Kopfbedeckungen / Schuhe, Einweg-Arbeitskleidung, Kleidungs- und Schuhbeutel, thermische Isolierung, etc.),
• Gebäude (wie Überdachung, Wärme- und Schalldämmung, Hauseinhüllung, Dachpappe, Lärmschutz, Bewehrung, Dichtungsmaterial, Dämpfungsmaterial, etc.),
• Automobile (z.B. in Innenraumfilter, Kofferraumauskleidungen, Hutablagen, Wärmeschutzschilde, Kofferraum-bodenbeläge, Filter, Dachhimmel, Dekorstoffe, Airbags, Schalldämpferunterlagen, Dämmstoffe, Autoplanen, Unterlagen, Fußmatten, Bänder, Tuft-Teppiche, Sitzbezüge, Türverkleidung, Charmeuse, etc.),
• Möbel und Innenausstattung (bspw. Möbelbau, Isolatoren für Arme und Rücken, Polsterfüllungen, Staubhüllen, Verkleidungen, Kantenverkleidung, Bettzeugkonstruktionen, Steppdecken, Federeinfassung, Matratzenkomponenten, Matratzenschoner, Fenstervorhänge, Wandverkleidungen, Teppichunterlagen, Lampenschirme, Dichtungen, Kissenfüllung, Matratzenfüllung, Einweg-Bettdecken, Vorhänge, etc.),
• Industrie (bspw. für Kabelisolierung, Isolierbänder, Schalldämmschichten, Klimaanlagen, Batterieseparatoren, Fleckentferner, Lebensmittelverpackungen, Klebeband, Wursthüllen, Käsehüllen, Kunstleder, Papiermacherfilze, Verpackung allgemein, etc.),
• Freizeit und Reisen (Schlafsäcke, Zelte, Gepäck, Handtaschen, Einkaufstaschen, Flugzeug-Kopfstützen, CD-Schutz, Kissenbezüge, Sandwich-Verpackungen, etc.),
• Schule und Büro (bspw. Buchumschläge, Briefumschläge, Landkarten, Schilder und Wimpel, Fahnen, Banknoten, etc.).

The non-woven fabric according to the preferred embodiments of the invention can be particularly advantageous for use in numerous applications. The high specific opacity with low basis weight can be particularly important when using the nonwoven fabric in one of the following products or in one of the following applications:

• Wipes (e.g. for babies, kitchens, cosmetics, hygiene, cleaning, polishing, dust, industry, mops, etc.),
• Filters (e.g. air filters, HVAC, air conditioning, coffee filters, tea filters, filter bags, food filters, cigarette filters, oil filters, filter cassettes, vacuum cleaner bags, dust filters, hydraulic filters, kitchen filters, HEVAC/HEPA/ULPA filters, respirators, etc.),
• absorbent hygiene products (such as absorbent pads, diapers, sanitary napkins, panty liners, incontinence products, tampons, towels, sanitary pads, flushable products, pads, nursing pads, disposable underwear, training pants, make-up removal pads, washcloths, etc.),
• medical applications (e.g. in disposable caps, gowns, masks and shoe covers, wound care, sterile packaging, coverstock, bandages, disposable clothing, nose strips, disposable underwear, bedding, transdermal drug delivery, shrouds, pads, treatment packs, heat packs, ostomy bags, fixation straps, incubator mattresses, mattress covers, etc.),

• Geotextiles (e.g. in plant protection covers, asphalt layers, soil stabilization, impregnation layers, pit linings, plant covers, weed control fabrics, greenhouse shading, etc.),
• Clothing (e.g. interlining fleece, clothing insulation and protection, handbag components, shoe components, belt inserts, industrial headgear / shoes, disposable work clothing, clothing and shoe bags, thermal insulation, etc.),
• Buildings (such as roofing, thermal and acoustic insulation, house cladding, roofing felt, soundproofing, reinforcement, sealing material, damping material, etc.),
• Automobiles (e.g. in cabin filters, trunk linings, parcel shelves, heat shields, trunk floor coverings, filters, headliners, decorative fabrics, airbags, silencer pads, insulating materials, car tarpaulins, pads, floor mats, tapes, tufted carpets, seat covers, door panels, charmeuse, etc.),
• Furniture and Interiors (e.g. furniture construction, arm and back insulators, padding, dust covers, trimmings, edge trimmings, bedding construction, quilts, feather edging, mattress components, mattress protectors, window curtains, wall coverings, carpet underlay, lampshades, gaskets, pillow filling, mattress filling, disposable bed covers, curtains, etc.)
• Industry (e.g. for cable insulation, insulating tape, sound insulation layers, air conditioning systems, battery separators, stain removers, food packaging, adhesive tape, sausage casings, cheese casings, artificial leather, papermaker's felt, packaging in general, etc.),
• Leisure and travel (sleeping bags, tents, luggage, handbags, shopping bags, airplane headrests, CD protectors, pillowcases, sandwich wraps, etc.),
• School and office (e.g. book covers, envelopes, maps, signs and pennants, flags, banknotes, etc.).

The invention may also feature in a wiper, face mask and dryer sheet comprising a nonwoven fabric of the invention according to any one of claims 1 to 16. Such a wipe, such a face mask or such a dryer towel can advantageously be characterized by an excellent specific opacity of greater than or equal to 1.0% m ² /g, or in a further embodiment of greater than or equal to 1.2% m ² / g, or in a very advantageous embodiment of greater than or equal to 1.5%·m ² /g. Such wipes, face masks and dryer sheets can also have a basis weight of less than or equal to 70 g/m ² , or in a further advantageous embodiment of less than or equal to 35 g/m ² , in particular less than or equal to 20 g/m ² , and thus a product with provide high opacity and low basis weight.

Such a wiping cloth can be used for a large number of different applications, for example in the hygiene, medical or sanitary sectors, and can give the user a feeling of high reliability in terms of strength and water absorbency. A low basis weight can also be particularly suitable for sensitive applications, such as cleaning measuring devices or optical devices such as glasses, lenses or binoculars.

A face mask as described above can be advantageous for hygienic applications, for example, where the low basis weight can ensure excellent flexibility and adaptability of the face mask to the facial contours of the user and the high specific opacity provides a versatile, non-transparent substrate for a large number of active ingredients, e.g cosmetic treatment of the facial skin.

Such a dryer sheet according to the invention can be suitable for use in tumble dryers and can impart a high degree of reliability due to the high specific opacity.

The aforementioned benefits of the wipers, face masks or dryer sheets of the present invention can be further enhanced when the nonwoven fabric is impregnated with a lotion. In fact, such a lotion can contain active ingredients for numerous applications, thus providing an easy-to-use product. For example, a wipe or face mask can be impregnated with a cleansing or care lotion that can be applied directly to the skin or surfaces. A dryer sheet can be used, for example be impregnated with a lotion, which is released during the drying process and cares for the laundry.

Advantageously, an aforesaid lotion is essentially non-water based. The water contained in a water-based lotion is absorbed by the nonwoven and can significantly reduce the specific opacity compared to the dry state. For example, a preferred lotion may be fat or wax based, thus providing a dry product with high specific opacity. Such a wax-based lotion can be present in a wipe, for example as a polish that is dispensed onto a surface during the polishing process. In the case of a fat-based lotion in a face mask, for example, the lotion can melt after contact with the skin due to the body temperature and can thus be released onto the skin. In the case of a dryer sheet, a laundry care product can be in the form of a wax-based lotion, for example, which is released onto the laundry during the drying process due to the increased temperature.

To produce the nonwovens according to the invention, a method mentioned at the beginning for the direct production of nonwovens from a spinning solution containing cellulose can be used. The spinning solution is preferably produced using a direct dissolving process, in particular the lyocell process, and is extruded through spinnerets. In particular, an aqueous solution of NMMO or another amine oxide is used as the solvent. Water, in particular, is used as a coagulant to precipitate the cellulose and to form the shaped bodies after extrusion of the dope.

1. a) Herstellung einer Cellulose aufweisenden Spinnlösung, insbesondere nach einem Direktlöseverfahren,
2. b) Extrusion der Spinnlösung durch zumindest eine Spinndüse mit eng benachbarten Düsenlöchern,
3. c) Verstreckung und Kontaktierung der extrudierten Spinnlösung mit Hilfe von Luftströmen mit hoher Geschwindigkeit,
4. d) Bildung des Vliesstoffes auf einer bewegten Oberfläche, insbesondere einem Bandförderer oder einer Trommel,
5. e) Waschen des Vliesstoffes, und
6. f) Trocknen des gewaschenen Vliesstoffes,

wobei in den Schritten c) und/oder d) auf die extrudierte Spinnlösung ein Koagulationsmittel aufgetragen wird um zumindest teilweise die in der Spinnlösung gelöste Cellulose auszufällen. Erfolgt die Herstellung der Spinnlösung nach einem Lyocell-Verfahren, so ist das Koagulationsmittel bevorzugt Wasser oder Wasser mit NMMO.In the process for producing the nonwovens according to the invention, the following steps are essentially carried out:

1. a) Production of a spinning solution containing cellulose, in particular using a direct solution process,
2. b) extrusion of the spinning solution through at least one spinneret with closely spaced nozzle holes,
3. c) drawing and contacting of the extruded dope by means of high-velocity air streams,
4. d) formation of the non-woven fabric on a moving surface, in particular a belt conveyor or a drum,
5. e) washing the nonwoven fabric, and
6. f) drying the washed nonwoven fabric,

wherein in steps c) and/or d) a coagulant is applied to the extruded spinning solution in order to at least partially precipitate the cellulose dissolved in the spinning solution. If the spinning solution is produced using a lyocell process, the coagulant is preferably water or water with NMMO.

During steps c) and d), regenerated cellulosic shaped bodies are formed which are connected to one another to form a network of shaped bodies. The shape and geometry of the shaped bodies formed can be controlled to a large extent by the process parameters such as the amount and time of application of the coagulation liquid and the speed of the (blown) air stream. In addition, the formation of material connections between individual filaments of the extruded spinning solution is strongly influenced by the point in time at which the coagulation liquid is applied. It has been found, for example, that compared to previous processes, the early application of coagulation liquid near the spinneret suppresses the formation of multifilaments and a high content of individual filaments in the end product is obtained. If, on the other hand, the coagulation of the shaped bodies takes place at a later point in time, i.e. away from the spinneret, filaments of the extruded spinning solution can touch in the blown air stream and bond to form a multifilament, since the cellulose has not yet precipitated and is therefore due to cohesion between the celluloses - Molecules of the individual filaments create a permanent bond, which can no longer be broken without destroying it. This cohesion is possible in particular when the filaments from the extruded spinning solution still contain solvent and have not yet finally coagulated. The individual filaments and multifilaments formed can then cross and touch in the blown air stream or during the formation of the nonwoven fabric in step d) and thus create nodes between the filaments. The individual filament sections are then cohesively connected to one another via the nodes and thus form the network of shaped bodies which makes up the nonwoven fabric according to the invention. In addition to the material connection at nodes, the filaments can also cross and overlap without one Train node and form a three-dimensional network of shaped bodies.

By increasing the stretching of the extruded spinning solution in the blown air flow, firstly finer filaments can be formed and secondly the cellulose chains in the filament can be aligned more strongly in the direction of the air flow. In addition, it has been shown that a higher air pressure or a higher speed of the air flow leads to more turbulence in the blown air flow. Due to the higher turbulence, however, filaments with varying diameters can be created, since the extruded spinning mass has not yet precipitated out at the time of stretching by the blown air stream and can therefore still be shaped. The individual and multifilaments or sections produced in this way can therefore have a diameter that varies over their length. In addition, the faster blown air flow generally leads to a reduction in the average diameter of the individual filaments. Both the production of finer individual filaments with a smaller diameter and the variation of the diameter over the longitudinal extent ultimately lead to an increase in the specific opacity of the nonwoven.

In addition to the speed of the blast air flow and the amount of coagulant applied, the take-off speed of the nonwoven fabric on the belt conveyor or the drum can also be varied and thus the weight per unit area of the nonwoven fabric can be influenced. Surprisingly, it has been found that by increasing the take-off speed, on the one hand, an increase in the production output per unit area is possible and, on the other hand, a nonwoven fabric with a low basis weight and high specific opacity can be achieved. The latter can be attributed in particular to the individual filament sections in the nonwoven fabric, which have a diameter of less than or equal to 15 μm over 90% of their longitudinal extent. The process can thus be used to produce a cost-effective nonwoven with particularly advantageous properties in terms of opacity.

By connecting several spinnerets in series in the process, it is also possible to create multi-layer nonwovens, with the networks of regenerated cellulosic shaped bodies being placed one on top of the other in the different layers and possibly subsequently consolidated, for example by water jets.

Brief description of the drawings

Fig. 1

Eine schematische Darstellung des erfindungsgemäßen Vliesstoffes einer ersten Ausführungsform,

Fig. 2

ein Mikroskopie-Bild des erfindungsgemäßen Vliesstoffes einer weiteren Ausführungsform,

Fig. 3

eine Punktdiagramm zur Darstellung der spezifischen Opazität der erfindungsgemäßen Vliesstoffe entsprechend der Beispiele B1 bis B7,

Fig. 4

eine schematische Darstellung der Messmethode zur Bestimmung der spezifischen Opazität,

Fig. 5

eine teilweise aufgerissene schematische Draufsicht auf einen Probenträger zur Bestimmung der Durchmesser der Einzelfilamentabschnitte,

Fig. 6

eine abgerissene Schnittansicht eines Wischtuchs,

Fig. 7

eine abgerissene Schnittansicht eines Trocknertuchs, und

Fig. 8

eine teilweise aufgerissene Draufsicht auf eine Gesichtsmaske.

In the following, the embodiments of the invention are described with reference to the drawings. Show it:

1

A schematic representation of the nonwoven fabric according to the invention in a first embodiment,

2

a microscopy image of the nonwoven according to the invention of a further embodiment,

3

a point diagram to show the specific opacity of the nonwovens according to the invention according to Examples B1 to B7,

4

a schematic representation of the measurement method for determining the specific opacity,

figure 5

a partially broken schematic plan view of a sample carrier for determining the diameter of the individual filament sections,

6

a torn sectional view of a wipe,

7

a broken sectional view of a dryer sheet, and

8

a partially cut away plan view of a face mask.

Ways to carry out the invention

1 shows a schematic representation of a nonwoven fabric 100 according to a first embodiment, which has a network 1 of regenerated cellulosic shaped bodies 2 . The shaped bodies 2 are bonded to one another at nodes 3 to form the network 1 . The shaped bodies 2 have in the network 1 individual filament sections 4 which each extend between nodes 3 . In addition to the individual filament sections 4 , the shaped bodies 2 also have multifilament sections 5 which, like the individual filament sections 4 , extend between nodes 3 or are connected to one another via the node points 3 to form the network 1 of shaped bodies 2 . The individual filament sections 4 can be optionally connected to other individual filament sections 4 or to multifilament sections 5 at the node points 3 .

In the dry state, the nonwoven 100 has a specific opacity of greater than or equal to 1.0%*m ² /g. In further embodiments, this specific opacity can occur depending on the process parameters and basis weight range up to 1.2%·m ² /g or particularly preferably up to 1.5%·m ² /g. 3 FIG. 12 shows, for example, a point diagram 50, the x-axis 51 representing the basis weight in g/m ² and the y-axis 52 representing the specific opacity in [%·m ² /g]. The straight lines 53, 54 and 55 each represent the lower limit for a specific opacity of 1.0%*m ² /g, 1.2%*m ² /g and 1.5%*m ² /g Vertical straight lines 56, 57 and 58 each stand for the limit values of the basis weight of 70 g/m ² , 35 g/m ² and 20 g/m ² . The measuring points 60 each stand for an embodiment B1 to B7 of the present invention. The measuring points 61, 62, 63 and 64 each stand for the comparison measurements V1 to V4. The details of measuring points 60 to 64 are explained in more detail in the description of the examples.

The single filament sections 4 according to the embodiment in 1 have a variable, varying diameter 7 along their longitudinal extent 6 . The diameter 7 of the individual filament sections 4 is a maximum of 15 μm along at least 90% of the longitudinal extent 6 of the individual filament sections 4 . The individual filament sections 4 have an average diameter 7 of between 1 μm and 8 μm along their longitudinal extent 6 .

In a further embodiment, the diameter 7 of the individual filament sections 4 over at least 90% of their longitudinal extension 6 can be a maximum of 10 μm, or a maximum of 7 μm in a particularly advantageous embodiment. The stretching of the extruded spinning solution in the blast air stream at high speed and turbulent flow gives the shaped bodies a diameter 7 that varies over their longitudinal extent 6. The multifilament sections 5 formed by connecting several filaments in the blast air stream therefore also have a diameter 9 that varies over their longitudinal extent 8. The multifilament sections 5 have a diameter of less than or equal to 100 μm over at least 90% of their longitudinal extent 8 .

The multifilament sections 5 are formed by the integral connection of individual filaments in the blown air flow and are thus composed essentially of several individual filament sections 4, which are intrinsically connected to one another inseparably via the cohesion of the cellulose molecules. The multifilament sections 5 are therefore not to be regarded as a strand of parallel single filament sections 4, but rather as a single one Multifilament section 5, which is caused by connecting several filaments.

2 shows an electron micrograph enlarged 250 times of a nonwoven fabric 101 according to the invention. The nonwoven fabric 101 has as before for 1 described the network 1 of cellulosic shaped bodies 2, which are connected via nodes 3 and consist of individual filament sections 4 and 5 multifilament sections.

The regenerated cellulosic moldings 2 in the nonwovens 100 and 101 according to 1 and 2 form an endless network 1, with essentially no filament ends of the shaped bodies 2 being visible. Due to the stretching process of the extruded spinning solution in the blast air flow, the individual filaments are connected to one another in a materially integral manner, so that any ends of the filaments are connected to other filaments and form a node 3 . For example, in the microscopy image of the exemplary nonwoven 101 according to 2 no loose filament ends are identified. However, it cannot be ruled out that in further post-treatment steps of the non-woven fabric 100, 101 - such as an additional hydroentanglement - filament ends are detached from the network 1 and are therefore present loosely in the non-woven fabric.

The shaped bodies 2 of the nonwoven fabric 101 are solution-spun cellulosic shaped bodies 2 and were produced from a spinning solution containing cellulose, water and NMMO using the Lyocell process. After the precipitation of the cellulose and the washing of the non-woven fabric 101, a non-woven fabric 101 according to the invention is obtained, which consists exclusively of cellulose apart from unavoidable impurities. Furthermore, the non-woven fabric 101 has no matting agent and coloring agent, giving it excellent strength and stability. In addition, the non-woven fabric 101 is free of adhesives or binders, which means that the mechanical flexibility of the non-woven fabric 101 is not adversely affected. In addition, the non-woven fabric 101 is well tolerated by the skin, since it is free of metallic residues, in particular of copper and nickel.

In a further embodiment, the non-woven fabric 100, 101 can have a plurality of layers which are connected to one another, but this has not been shown in any more detail in the figures. The connection of the layers can be materially connected Cohesion between the cellulose molecules of the shaped bodies 2, or for example positively and/or non-positively by mechanical entanglement of the shaped bodies 2 - for example in the course of hydroentanglement (hydroentanglement) - take place.

The nonwoven fabric 100 according to the invention is particularly suitable for producing a wipe 200, a face mask 300 and a dryer towel 400, the nonwoven fabric 100 having a specific opacity of greater than or equal to 1.0% gm ^-2 .

So shows 6 a wipe 200, which has a nonwoven fabric 100 according to the invention described above. The non-woven fabric 100 is impregnated with a lotion 210 which penetrates at least partially into the non-woven fabric 100 and forms a penetration area 215 . The lotion 210 can contain a solvent such as water, but is preferably based on oil, fat or wax and is therefore essentially free of water. Depending on the lotion 210, such a wiping cloth 200 can be suitable for hygienic use as well as for the treatment of surfaces

In 7 a dryer sheet 400 is shown, which also has a nonwoven fabric 100 according to the invention. A lotion 410 is in turn applied to the nonwoven fabric 100 . The lotion 410 can penetrate into the structure of the non-woven fabric 100 and wet it, but this is not shown in more detail in the figures. In particular, the nonwoven 100 can be completely or partially wetted by the lotion 410 . The lotion 400 is preferably free of aqueous solutions and is released to the laundry contained therein at an elevated temperature, for example during a drying process in a tumble dryer.

8 Finally, FIG. 12 shows a face mask 300, which has a nonwoven fabric 100 as a base support and is coated with a lotion 310 on the inside (facing the wearer's face). The lotion 310 is preferably designed in such a way that it can be detached from the nonwoven fabric 100 by the skin temperature of the wearer and is released onto the skin. The face mask 300 also includes a plurality of cutouts 320 to easily conform to the wearer's face.

The Figures 3 , 4 and 5 are described below to explain the examples.

examples Specific Opacity Measurement:

A 10×10 cm sample is taken at random from the nonwoven to be measured and conditioned at 23° C. (± 2° C.) and 50% (± 5%) relative humidity for 24 hours before carrying out the measurement. After conditioning, the sample is weighed and the basis weight in g/m ² is determined.

A Konica Minolta Inc. spectrophotometer CM-600d with a measuring head attachment for opacity measurements (Konica Minolta, non-glazed, plastic, CM-A180 Target Mask 8 mm (w/o plate)) was used for all measurements and the device was equipped with the black standard (Konica Minolta Inc., Zero Calibration Tube CM-A182) and with the white standard (Konica Minolta Inc., CM-A177).

The measuring device settings and software used for all calibration measurements and opacity measurements can be found in Table 1. Table 1: Measuring device setup for calibration and measurements software Konica Minolta Inc., Color Data Software CM-S100 w, SpectraMagic™ NX; Version: CM-S100w 2.70.0006 gloss component SCE output reflection 570nm measuring surface D= 8mm lighting area D= 11mm First type of light C Second type of light (no) observer 10°

To determine the opacity, an opacity measuring chart with a black and a white area (TQC Test Chart, format A4, Art. No. VF2345) is used.

The reflectance values of a sample are measured over the black and white areas of the opacity measurement card. 4 shows a schematic representation of a sample 70 made from a nonwoven fabric 100 according to the invention was removed by cutting or punching out. The sample 70 has edge lengths 71, 72 of 10 cm. The points 73, 74, 75, 76 and 77, at which the measuring points 1 to 5 are recorded, are in each case in the corners and in the middle of the sample 70.

First, the sample 70 is positioned over the black area 81 of the opacity measurement card 80 and the measurement points 1 to 5 are determined for the reflection of the sample over black. The sample 70 is then positioned over the white area 82 of the opacity measurement card 80 and the recording of measurement points 1 to 5 for the reflection of the sample over white is repeated.

wobei Reflexion über schwarz dabei für die Reflexion der Probe über dem schwarzen Opazitätsmesskartenhintergrund bei einer Wellenlänge von 570 nm steht, und vice versa Reflexion weiß die Reflexion der Probe über dem weißen Opazitätsmesskartenhintergrund bei einer Wellenlänge von 570 nm bezeichnet.The opacity of the sample for measuring points 1, 2, 3, 4 and 5 can then be calculated separately using formula (2): $$\mathrm{opacity}\left[\%\right]=100\cdot \mathrm{reflection}\mathrm{above}\mathrm{black}/\mathrm{reflection}\mathrm{above}\mathrm{white},$$

where reflection over black is the reflection of the sample over the black opacity map background at a wavelength of 570 nm, and vice versa reflection white is the reflection of the sample over the white opacity map background at a wavelength of 570 nm.

The mean value of the opacity values for all 5 measuring points is then calculated and the specific opacity of the sample is determined according to formula (1), as previously defined, by dividing the mean value by the basis weight of the sample: $$\mathrm{specific}\mathrm{opacity}\left[\%\cdot {\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">m</figure-callout>}}^2/\mathrm{G}\right]=\mathrm{opacity}\left[\%\right]/\mathrm{basis\; weight}\left[\mathrm{G}/{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">m</figure-callout>}}^2\right].$$

The specific opacity stands for the opacity normalized by the basis weight of the sample.

Microscopic determination of the diameter of the individual filament sections:

To determine the diameter of the individual filament sections, a 1 cm×1 cm sample 90 was randomly taken from the fleece and conditioned at 23° C. (±2° C.) and 50% (±5%) relative humidity for 24 hours before carrying out the measurement .

Subsequently, the sample 90, as in figure 5 shown, placed on a transparent sample carrier 91 and covered with a coverslip 92. The Coverslip 92 was weighted down with a metal frame 93 (weighing 62.6 g). The metal frame 93 has a window 94 for looking through the cover glass 92 onto the sample 90 . A sample photograph is taken of the sample 90 in a light microscope in black/white transmitted light at a magnification of 100 times.

A square 95 measuring 1 mm×1 mm is randomly selected from the sample holder and two diagonals 96, 97 are drawn into this square 95. Those individual filament sections 98 which intersect the diagonals 96, 97 down to a measuring depth of 150 μm are measured by determining an equivalent diameter 99 (by circle equivalence). The upper side of the pressed fleece is defined as the zero point. Nonwovens that are thinner than 150 µm can thus be recorded in their entire thickness with this method. If individual filament sections are cut at the corner points of the square, their equivalent diameter 99 can still be fully recorded using circle equivalence.

The measurement method described can be repeated at two other fleece locations and the mean value can be formed over all equivalent diameters 99 of the individual filament sections 98 of those fleece locations. Multifilament sections and knots are ignored in the measurement.

Description of the examples:

7 examples (B1 to B7) of the nonwovens according to the invention are shown below.

• Eine Lyocell-Spinnlösung, aufweisend 10 % Cellulose, wurde gemäß einem eingangs beschriebenen bekannten Verfahren hergestellt,
• Die Spinnlösung wurde durch eng aneinander gereihte Öffnungen einer Spinndüse extrudiert und in einem Blasluftstrom mit hoher Geschwindigkeit verstreckt (für die verfahrenstechnischen Einzelheiten des Verfahrens wird auf den eingangs erwähnten Stand der Technik verwiesen),
• Während und/oder nach der Verstreckung wurde die Cellulose aus der extrudierten Spinnlösung zumindest teilweise durch Auftragen eines Koagulationsmittels ausgefällt um die Formkörper zu bilden,
• Der Vliesstoff wurde schließlich durch Ablegen der Formkörper auf einem in Bewegung befindlichen Bandförderer gebildet und anschließend gewaschen und getrocknet.

The nonwovens (B1 to B7) given by way of example were produced in accordance with a process comprising the following steps:

• A lyocell dope containing 10% cellulose was prepared according to a known method described above,
• The spinning solution was extruded through closely spaced orifices of a spinneret and stretched in a blown air stream at high speed (for the technical details of the process, reference is made to the prior art mentioned at the outset),
• During and/or after the stretching, the cellulose was at least partially precipitated from the extruded spinning solution by applying a coagulant in order to form the shaped bodies,
• The non-woven fabric was finally formed by depositing the shaped bodies on a moving belt conveyor and then washing and drying.

To demonstrate the advantageous properties according to the invention of the webs produced in this way with regard to their specific opacity, the blast air pressure (the speed of the blast air flow) and the amount of coagulation liquid were varied during the process in comparison to a reference example (B4). The basis weight could be adjusted by specifically controlling the belt conveyor speed. The parameters for preparing examples B1 to B7 are summarized in Table 2. Table 2: Production parameters for nonwovens according to the invention Example Blowing air pressure [compared to ref.] coagulation flow. [compared to ref.] Weight per unit area [g/m ² ] Specific opacity [%·m ² /g] B1 1× 0.25x 33.0 1.07 B2 1× 0.50× 61.2 1:12 B3 1× 0.75x 15.8 1.56 B4 - Ref. 1× 1.00x 23:6 1.66 B5 2× 1.25× 15.2 1.92 B6 2x 1.50× 18.2 1.93 B7 2x 1.75X 15.6 2:19

The examples B1 to B7 obtained in this way consist of 100% cellulose, namely regenerated Lyocell moldings, and all have a specific opacity of more than 1%·m ² /g and a weight per unit area of less than 70 g/m ² .

In general, it was found that through targeted control of the blast air flow (in particular the speed of the blast air flow by changing the pressure), a variation in the diameter distribution in the individual filament sections was achieved, with higher blast air flow speeds or higher blast air pressure leading to greater stretching and thus finer average Diameters of the single filament sections led. Also could about the variation of the amount of coagulation liquid, which the extruded spinning mass was applied, the formation of individual filaments can be influenced and thus the specific opacity of the nonwoven can be controlled. An increase in the amount of coagulation liquid was accompanied by a higher content of individual filament sections, which in turn led to a higher specific opacity.

The parameters (air pressure and amount of coagulation liquid) in Table 2 were given as factors based on Reference Example B4. The reference parameters for reference example B4 were determined by adjusting the production plant so that a nonwoven with an average basis weight of 25 g/m ² ±10% and an average specific opacity of 1.6%·m ² /g ±10% was obtained .

The specific opacity of the nonwovens B1 to B7 was determined according to the measurement method set out above. The measured values determined are shown in Table 3. Table 3: Measured values for nonwovens according to the invention Example reflection black reflection white Opacity [%] mass [g] Weight per unit area [g/m ² ] Specific opacity [%·m ² /g] B1 29.36 83.09 35.33 0.330 33.0 1.07 B2 57.80 84.45 68.44 0.612 61.2 1:12 B3 20.35 82.82 24.57 0.158 15.8 1.56 B4 32.46 83.06 39.08 0.236 23:6 1.66 B5 24.23 82.88 29:23 0.152 15.2 1.92 B6 29:19 83.22 35.08 0.182 18.2 1.93 B7 28.34 82.98 34:16 0.156 15.6 2:19

Comparative examples:

Table 3 shows comparative examples C1 to C4 to illustrate the advantageous properties of examples B1 to B7. The weight per unit area and the specific opacity of the comparative examples were determined in accordance with the measurement method described above. Table 3: Properties of the comparative examples Example material production method Weight per unit area [g/m ² ] Specific opacity [% m/g] V1 100% polypropylene Carded, thermobond 32.0 0.74 v2 100% Lyocell Carded, water jet vf. 79.7 0.88 V3 100% cupro spunbonded 40.5 0.98 V4 100% polyester spunbond 19.0 1.51

Comparative example C1 is a carded, thermally bonded (thermobond) fleece made from 100% polypropylene fibers of the Sawabond 4138 type, Sandler AG. The fleece has a low weight per unit area of 32 g/m ² , but the measurement showed a low specific opacity of only 0.74%·m ² /g.

Comparative example C2 is a carded, hydroentangled fleece made from 100% Lyocell staple fibers from Lenzing AG. The fleece has a comparatively high basis weight of 79.7 g/m ² , but still only achieves a specific opacity of 0.88%·m ² /g.

A 100% cupro spunbonded nonwoven from Asahi Kasei Corp. is used as comparative example C3. of the type Bemliese SE384G. With a basis weight of 40.5 g/m ² the spunbonded nonwoven can only achieve a specific opacity of 0.98%·m ² /g.

Comparative example C4 shows a 100% polyester spunbond fleece of the type Reemay 2250 from Berry Global Inc. The polyester spunbond fleece has an excellent specific opacity of 1.51% m ² at a low basis weight of 19.0 g/m ² / G.

In the scatter plot 50 of the 3 Comparative examples V1 to V4 are each shown as measured values 61, 62, 63 and 64 and placed in relation to measured values 60 of examples B1 to B7 according to the invention.

Claims (20)

1. A nonwoven, including a network (1) of molded bodies (2), the nonwoven (100, 101), in the dry state, having a specific opacity of greater than or equal to 1.0 %·m²/g, characterized in that the molded bodies (2) are regenerated cellulosic molded bodies (2) and are materially interconnected via node points (3) to form the network (1), the regenerated cellulosic molded bodies (2) comprising monofilament sections (4) extending between node points (3), whose diameter (7) varies along their lengthwise extension (6) and which have a diameter (7) of less than or equal to 15 µm for at least 90 % of their lengthwise extension (6).
2. The nonwoven as claimed in claim 1, characterized in that the regenerated cellulosic molded bodies (2) comprise multifilament sections (5) extending between node points (3), which consist of several materially interconnected and essentially parallel monofilament sections (4), the multifilament sections (5) having a diameter (9) of less than or equal to 100 µm for at least 90 % of their lengthwise extension (8).
3. The nonwoven as claimed in claims 1 or 2, characterized in that the regenerated cellulosic molded bodies (2) form an essentially endless network (1) without visible filament ends.
4. The nonwoven as claimed in one of claims 1 to 3, characterized in that the nonwoven (100, 101) is essentially free of matting agents and colorants.
5. The nonwoven as claimed in one of claims 1 to 4, characterized in that the nonwoven (100, 101) consists essentially only of cellulose.
6. The nonwoven as claimed in one of claims 1 to 5, characterized in that the regenerated cellulosic molded bodies (2) are solution-spun cellulosic molded bodies (2), particularly according to a lyocell process.
7. The nonwoven as claimed in claim 6, characterized in that the monofilament sections (4) have a solid, particularly a rounded, cross-section.
8. The nonwoven as claimed in one of claims 1 to 7, characterized in that the nonwoven (100, 101) is essentially free of binders or adhesives.
9. The nonwoven as claimed in one of claims 1 to 8, characterized in that the nonwoven (100, 101) is essentially free of copper and/or nickel.
10. The nonwoven as claimed in claim 9, characterized in that the nonwoven (100, 101) has a copper content of less than 5 ppm and/or a nickel content of less than 2 ppm.
11. The nonwoven as claimed in one of claims 1 to 10, characterized in that the monofilament sections (4) have a diameter (7) of less than 10 µm, more preferably of less than 7 µm, for at least 90 % of their lengthwise extension (6).
12. The nonwoven as claimed in one of claims 1 to 11, characterized in that the monofilament sections (4) have an average diameter (7) of greater than or equal to 1 µm and less than or equal to 8 µm.
13. The nonwoven as claimed in one of claims 1 to 12, characterized in that the nonwoven (100, 101), in the dry state, has a specific opacity of greater than or equal to 1.2 %·m²/g, more preferably of greater than or equal to 1.5 %·m²/g.
14. The nonwoven as claimed in one of claims 1 to 13, characterized in that the nonwoven (100, 101) has a basis weight of less than or equal to 70 g/m², more preferably of less than or equal to 35 g/m², most preferably of less than or equal to 20 g/m².
15. The nonwoven as claimed in one of claims 1 to 14, characterized in that the nonwoven (100, 101) includes property-refining and surface-refining or property-changing and surface-changing substances or processing-facilitating agents at a content of no more than 1 % by weight, more preferably of no more than 0.5 % by weight.
16. The nonwoven as claimed in one of claims 1 to 15, characterized in that the network (1) of regenerated cellulosic molded bodies (2) includes several interconnected layers.
17. The use of a nonwoven (100, 101) as claimed in one of claims 1 to 16 for the production of hygiene products, particularly of absorbent layers, wipes, diapers, sanitary napkins, liners, pads, disposable clothing and the like, as well as for the production of filters, industrial products, clothing, furnishings, automotive, leisure products, or products for schools and offices.
18. A wipe, face mask, or dryer sheet, including a nonwoven (100, 101) as claimed in one of claims 1 to 16, having, in particular, a specific opacity of greater than or equal to 1.0 %·m²/g.
19. The wipe, face mask, or dryer sheet as claimed in claim 18, characterized in that the nonwoven (100, 101) is impregnated with a lotion (210, 310, 410).
20. The wipe, face mask, or dryer sheet as claimed in claim 19, characterized in that the lotion (210, 310, 410) is essentially non-water-based.

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