TWI782967B - Nonwoven cellulose fiber fabric with fibers, method and device for manufacturing the same, method of using the same, and product comprising the same - Google Patents

Abstract

A nonwoven cellulose fiber fabric (102), in particular directly manufactured from lyocell spinning solution (104), wherein the fabric (102) comprises a network of substantially endless fibers (108), and wherein at least 1% of the fibers (108) has a non-circular cross sectional shape having a roundness of not more than 90%.

Description

Nonwoven cellulosic fiber fabrics, methods and devices for making them, methods for using them, and products incorporating them

The present invention relates to nonwoven cellulosic fiber webs, methods of making nonwoven cellulosic fiber webs, devices for making nonwoven cellulosic fiber webs, products or composites, and methods of use.

Lyocell technology is about cellulose wood pulp or other cellulose-based raw materials in polar solvents (for example, N-methylmorpholine-N-oxide, which can also be called "oxidation amine” or “AO”) to produce a viscous, highly shear-thinning solution that can be converted into a range of useful cellulosic materials. Commercially, this technology is used to produce a range of cellulose staple fibers (commercially available under the trade name TENCEL® from Lenzing AG, Lenzing, Austria) widely used in the textile industry. Other Cellulose Products from Lyocell Technology has also been used.

Cellulose staple fibers have long been used as components for conversion into nonwoven webs. However, adapting lyocell technology to directly produce nonwoven webs would yield properties and performance not currently available in cellulosic web products. Although synthetic polymer technology cannot be directly applied to lyocell due to important technical differences, it can be considered as a cellulose version of the meltblown and spunbond technologies widely used in the synthetic fiber industry.

Many studies have been carried out to develop lyocell solutions (especially WO 98/26122, WO 99/47733, WO 98/07911, US 6,197,230, WO 99/64649, WO 05/106085, EP 1 358 369, EP 2 013 390) Techniques for direct formation of cellulosic webs. Additional techniques are disclosed in WO 07/124521 Al and WO 07/124522 Al.

It is an object of the present invention to provide cellulosic fabrics with adjustable mechanical stability.

In order to achieve the above stated purpose, provide non-woven cellulose fiber fabrics, methods for manufacturing non-woven cellulose fiber fabrics, devices, products or composites for manufacturing non-woven cellulose fiber fabrics, and Instructions.

According to an exemplary embodiment of the present invention, there is provided a (particularly a solution-blown) nonwoven cellulosic fiber fabric (which may be produced directly (particularly in an in situ process or in a continuously operating production line) In a continuous process performed) manufactured from a lyocell spinning solution) and wherein at least 1% of the fibers have a non-circular cross-sectional shape (in particular along the longitudinal direction of the entire fiber) with a roundness of not more than 90% extending or extending along the longitudinal direction of only part of the fiber stretch).

According to another exemplary embodiment, there is provided a method of manufacturing (in particular a solution-blown) nonwoven cellulosic fiber fabric directly from a lyocell spinning solution, wherein the method comprises passing the lyocell spinning solution through an orifice ( It may be implemented as (or may form part of) a spinning nozzle or an extrusion unit) extruded by means of air flow into a coagulated fluid environment (in particular a dispersed coagulated fluid environment) to form substantially endless fibers which are collected in Fabric is formed on the fiber support unit, and the process parameters are adjusted so that at least 1% of the fibers have a non-circular cross-sectional shape with a circularity not greater than 90%.

According to a further exemplary embodiment, there is provided an apparatus for manufacturing (in particular, solution-blown) nonwoven cellulosic fiber fabrics directly from a lyocell spinning solution, wherein the apparatus comprises a spray nozzle having an orifice, which is passed through configured to extrude the lyocell spinning solution under an air stream; a coagulation unit configured to provide a coagulating fluid environment for the extruded lyocell spinning solution to form substantially endless fibers; a fiber support unit , which is configured to collect fibers to form a fabric; and a control unit (such as a processor configured to execute a program code for making a nonwoven cellulosic fiber fabric directly from a lyocell spinning solution), which Configured to adjust process parameters such that at least 1% of the fibers have a non-circular cross-sectional shape with a circularity no greater than 90%.

According to yet another embodiment, the nonwoven cellulosic fiber fabric having the properties described above is for use in at least one of the group consisting of: wipes; filters; absorbent hygiene products; products for medical applications; Geotextiles; agricultural fabrics; clothing; products used in construction technology; automotive products; furnishing; industrial products; and beauty, leisure products related to leisure, sports or travel; and products related to school or office.

According to yet another embodiment, a product or composite comprising a fabric having the properties described above is provided.

In the context of the present application, the term "nonwoven cellulosic fiber fabric" (which may also be denoted as nonwoven cellulosic filament fabric) may particularly denote a fabric or web consisting of a plurality of substantially endless fibers. The expression "substantially endless fibers" has in particular the meaning of filament fibers having a significantly longer length than conventional staple fibers. In alternative formulations, the term "substantially endless fibers" may especially have the meaning of a network of filament fibers having a significantly smaller amount of fiber ends per volume than conventional staple fibers. ends per volume). In particular, according to an exemplary embodiment of the invention, the endless fibers of the fabric may have an amount of fiber ends per volume of less than 10,000 ends/cm ³ , in particular less than 5,000 ends/cm ³ . For example, when staple fibers are used as substitutes for cotton, they may have a length of 38 mm (corresponding to the typical natural length of cotton fibers). In contrast, the substantially endless fibers of the nonwoven cellulosic fiber web can have a length of at least 200 mm, in particular of at least 1000 mm. However, those of ordinary skill in the art will be aware of the fact that even endless cellulosic fibers may have interruptions, which may be formed during fiber formation, and/or post-fiber formation processes. As a result, nonwoven cellulosic fiber fabrics made from substantially endless cellulosic fibers have a significantly lower number of fibers per mass compared to nonwoven fabrics made from staple fibers of the same denier . Nonwoven cellulosic fiber fabrics can be produced by spinning a plurality of fibers and drawing and stretching the plurality of fibers towards a preferably mobile fiber support unit. Thus, a three-dimensional network or web of cellulosic fibers is formed, constituting a nonwoven cellulosic fiber web. The fabric may be made from cellulose as a major component (or as a component only).

In the context of the present application, the term "lyocell spinning solution" may specifically denote a solvent (for example, a polar solution of a material such as N-methyl-morpholine N-oxide; NMMO; "amine oxide"; or "AO") in which cellulose (eg, wood pulp or other cellulosic raw material) is dissolved. Lyocell spinning solution is a solution rather than a melt. Cellulose filaments can be produced from lyocell spinning solutions by reducing the concentration of solvent (eg, by contacting the filaments with water). The process of producing cellulose fibers starting from a lyocell spinning solution can be described as coagulation.

In the context of the present application, the term "air flow" may specifically mean when the lyocell spinning solution leaves the nozzle (and/or after the lyocell spinning solution leaves the nozzle, or after the lyocell spinning solution has exiting the spinning nozzle) a flow of gas (eg air) substantially parallel to the direction of movement of the cellulose fibers or their preforms (ie the lyocell spinning solution).

In the context of the present application, the term "coagulation fluid" may specifically denote a non-solvent fluid (i.e., a gas and/or liquid, optionally including solid particles) having the properties of diluting the lyocell spinning solution, And the ability to exchange with solvent to some extent to make cellulose fibers from lyocell filaments. For example, such condensed fluid may be water mist.

In the context of the present application, the term "process parameters" may specifically denote the substances, and/or the set of devices used to manufacture the nonwoven cellulosic fiber fabric All physical parameters, and/or chemical parameters, and/or device parameters of the component, which may affect the properties of the fibers and/or fabrics, especially the fiber diameter and/or fiber diameter distribution. Such process parameters can be adjusted automatically by the control unit and/or manually by the user to tune or adjust the properties of the fibers of the nonwoven cellulosic fiber web. Physical parameters that may affect the properties of the fibers (in particular their diameters or diameter distribution) may be the temperature, pressure, and/or density. Chemical parameters may be concentrations, amounts, pH values of the media involved (such as lyocell spinning solutions, coagulation fluids, etc.). Device parameters may be the size and/or distance between the orifices, the distance between the orifices and the fibrous support unit, the transport speed of the fibrous support unit, the provision of one or more optional in-situ post-processing units, air flow, and the like.

The term "fiber" may particularly denote an elongated piece comprising cellulosic material, for example, of substantially circular, or irregularly formed cross-section, randomly intertwined with other fibers. The fibers may have an aspect ratio greater than 10, especially greater than 100, more particularly greater than 1000. The aspect ratio is the ratio between fiber length and fiber diameter. Fibers can pass through by coalescing (so that a unitary multifibrous structure is formed) or by friction (so that the fibers remain separated but are weakly mechanically coupled by frictional forces applied when the moving fibers physically contact each other). interconnected to form a network. A fiber may have a substantially cylindrical form, however it may be straight, curved, kinked, or arcuate. Fibers may consist of a single homogeneous material (ie, cellulose). However, the fibers may also contain one or more additives. Liquid material, such as water or oil, can accumulate between fibers.

In the context of this document, a "spray nozzle with orifices" (which may eg be denoted "arrangement of orifices") may be any structure comprising an arrangement of orifices arranged linearly.

In the context of the present application, the term "roundness" may specifically mean the ratio between the inscribed circle and the circumscribed circle of a fiber cross-section, that is, just enough to fit inside the cross-section of the fiber, and the shape of the cross-section surrounding the fiber The maximum and minimum dimensions of the circle. In order to determine the roundness, the section perpendicular to the direction of fiber extension can be intersected with the fiber. Therefore, the roundness can be expressed as a measure of how close the cross-sectional shape of each fiber is to a circle of 100% roundness. For example, the cross-section of each fiber may have an oval (particularly elliptic) shape, or may have a polygonal shape. In general, the locus defining the outer limit of the fiber cross-section may be any closed plane line showing deviation from a circle. The cross-section of individual fibers may be completely circular, or may have one or more sharp edges.

According to an exemplary embodiment, there is provided a nonwoven cellulosic fiber fabric having substantially endless fibers and exhibiting substantial deviations from an overall cylindrical shape. From a mechanical point of view, this also leads to the fact that in the presence of mechanical loads, the preferred bending direction of the fiber is defined by the design of the fiber cross-section. For example, where a fiber has an elliptical cross-sectional shape with two major axes (ie, a major axis and a minor axis) of different lengths, bending will occur primarily with the minor axis as the bending line under application of force. Thus, the bending properties of such fiber webs are no longer statistical and unpredictable, but instead a definite order of the nonwoven cellulosic fiber web is added. Thus, by simply influencing the cross-sectional geometry of the individual fibers, the defined mechanical properties of the fabric can be tuned in a simple manner. Can also borrow The lay down or network behavior of the fibers is adjusted by adjusting the deviation of some or substantially all of the fibers from perfect circularity. In addition, non-woven cellulosic fiber fabrics with anisotropic mechanical properties can be produced when the non-cylindrical fibers are arranged in an ordered or partially ordered manner.

100: device

102: (non-woven cellulose fiber) fabric

104: Lyocell spinning solution

106: Condensed Fluid

108: fiber

110: wood pulp

112: water container

113: Measuring unit

114: storage tank

116: solvent container

118: Concentration unit

119: Hybrid unit

120: dissolving unit

122: spray nozzle

124: Fiber forming unit

126: Orifice

128:Agglomeration unit

132: fiber support unit

134: Further processing unit

136:Coiler

140: control unit

146: Airflow

180: washing unit

200: layers

202: layer

204: merge position

236: Commonly aligned axes

238: Parallel alignment axis

264: cross position

270: Deformation unit

272: Forming Fluid

274: details

280: Inscribed circle

282:Circumscribed circle

290:Priority Arrangement Direction

R: radius of inscribed circle

r: circumcircle radius

The invention will be described in more detail below with reference to examples of embodiments, but the invention is not limited thereto: FIG. 1 shows a diagram for the manufacture of nonwoven fibers directly formed from a lyocell spinning solution, according to an exemplary embodiment of the invention. In the device of viscose fabric, the lyocell spinning solution is coagulated by coagulating fluid.

FIGS. 2 to 4 show experimentally captured images of nonwoven cellulose fiber fabrics according to exemplary embodiments of the present invention, wherein the consolidation of individual fibers is accomplished through specific process control.

5 and 6 show experimentally captured images of nonwoven cellulosic fiber fabrics according to exemplary embodiments of the present invention (where swelling of the fibers has been completed), wherein FIG. 5 shows the fiber fabric in a dry, non-swollen state, and FIG. 6 Shows fiber fabrics in a wet swollen state.

7 shows experimentally captured images of a nonwoven cellulosic fiber fabric according to an exemplary embodiment of the present invention, wherein the formation of two superimposed layers of fibers is accomplished by performing a specific process with two nozzles in series.

Figure 8 shows a schematic drawing showing that when the roundness of the fiber cross-section is adjusted to deviate from a circular cross-section, a well-defined bend of the fiber can be promoted.

Figure 9 shows nonwoven cellulose fibers according to an exemplary embodiment of the present invention Experimentally captured images of dimensional fabrics depicting fibers with cross-sectional shapes that deviate from circular.

FIG. 10 shows an experimentally captured image of a nonwoven cellulosic fiber fabric according to an exemplary embodiment of the present invention, wherein fibers having a cross-sectional shape deviated from a circle are partially twisted.

Figure 11 shows an experimentally captured image of a nonwoven cellulose fiber fabric according to an exemplary embodiment of the present invention, consisting of three stacked layers with different fiber diameters.

Fig. 12 shows how to calculate the roundness of a fiber having a cross-section deviating from a circular cross-section as the ratio between the inscribed circle and the circumscribed circle of the fiber's cross-section according to an exemplary embodiment of the present invention.

Figure 13 illustrates an apparatus for manufacturing a nonwoven cellulosic fiber fabric in which the process is controlled to trigger the formation of merge sites between fibers, according to another exemplary embodiment of the present invention.

FIG. 14 illustrates components of an apparatus for manufacturing a nonwoven cellulosic fiber fabric in which the process is controlled to trigger a non-circularity with deviation from circularity (by elliptical orientation during agglomeration), according to yet another exemplary embodiment of the present invention. The formation of the merged position between the fibers without the roundness of the end fibers applying a transverse force).

Fig. 15 shows a part of an apparatus for making a nonwoven cellulosic fiber fabric having an orifice shaped to form a true circle having a deviation from a circular shape, according to yet another exemplary embodiment of the present invention. The degree of roundness of the fiber, and lead to mechanical strengthening of the fabric.

16 is a schematic diagram of a nonwoven cellulosic fiber fabric according to an exemplary embodiment of the present invention, depicting fibers having a cross-sectional shape that deviates from a circle, As a result, the fibers are generally arranged along a preferential direction.

In the following, additional exemplary embodiments of nonwoven cellulosic fiber webs, methods of making nonwoven cellulosic fiber webs, devices, products or composites for making nonwoven cellulosic fiber webs, and methods of use are described.

In an embodiment, at least 3%, especially at least 5%, more especially at least 10% of the fibers have a non-circular cross-sectional shape with a circularity not greater than 90%. Even more specifically, it is possible that at least 10%, at least 20%, at least 30%, at least 50%, or at least 80% of the fibers have no greater than 90%, no greater than 80%, no greater than 70%, no greater than 60%, no A non-circular cross-sectional shape with a circularity greater than 50%, or not greater than 30%. The higher the amount of fibers deviating from the circular cross-sectional shape, the higher the deviation of the produced fiber fabric from isotropic mechanical behavior and the more pronounced the adjustability of the mechanical properties of the fabric.

In an embodiment, at least 1%, at least 10%, at least 20%, at least 30%, at least 50%, or at least 80% of the fibers have no more than 80%, especially no more than 70%, more particularly no more than 50% % roundness of non-circular cross-sectional shape. Even more specifically, it may be that at least 1% of the fibers have a non-circular cross-sectional shape of no greater than 60%, no greater than 50%, no greater than 40%, or no greater than 10% circularity. The higher the amount of fibers deviating at least partially from a circular cross-sectional shape, the higher the deviation of the produced fiber fabric from isotropic mechanical behavior and the more pronounced the adjustability of the mechanical properties of the fabric.

For example, by adjusting the number and/or shape of the orifices, the percentage of fibers having a non-circular cross-sectional shape with a corresponding roundness value can be adjusted by The orifice emits a lyocell spinning solution which, after coagulation, forms fibers. Additionally or alternatively, for example by adjusting the number of filaments of the lyocell spinning solution which is subjected to a mechanical impact for changing the cross-sectional shape before coagulation, non-circular shapes with corresponding roundness values can be adjusted. The fiber percentage of the cross-sectional shape.

In the embodiment, on the basis of the non-woven standard WSP90.3, the smoothness and specific hand feeling of the fabric were respectively measured at 2mNm ² /g and 70mNm ² /g with the “Handle-O-Meter” range between g. By varying the process parameters of the manufacturing method, the smoothness can thus be varied within a wide range. Sufficient and definite stability of the fabric may already be ensured when designing fibers with non-circular cross-sections or non-cylindrical geometries. The smoothness of the surface (even very high smoothness) can then be freely adjusted without compromising the stability of the fabric.

On the basis of nonwoven standard WSP90.3, the smoothness of the mentioned fabrics can be measured with "Fabric Hand Tester" (commercially available from Thwing-Albert Instrument Co., Philadelphia, PA). To determine the smoothness of a fabric, lower the pivoting arm of the "Fabric Handle Tester" and press a sample of fabric (eg, with square dimensions of 10cmx10cm) into adjustable parallel slits. Measure the force required to press the sample into the slit. During this procedure, bending and frictional forces are applied to the sample. The average value of the measurements in the CD and MD directions corresponds to the average force required to press the sample through the slit. The ratio between the average force (eg expressed in mN) and the basis weight of the fabric (eg expressed in ^g /m2) gives the smoothness value (measured as a specific hand), expressed in ^mNm2 /g, which represents the fabric material smoothness.

In an embodiment, the fibers have a copper content of less than 5 ppm and/or have a nickel content of less than 2 ppm. The ppm values mentioned in this application are all by mass (not by volume). In addition, heavy metal contamination of fibers or fabrics may not exceed 10 ppm for each individual chemical element. Due to the use of lyocell spinning solutions as the basis for forming endless fiber-based fabrics (especially when solvents (such as N-methyl-morpholine N-oxide; NMMO) are involved), the fabrics have heavy metals such as copper or nickel ( which may cause an allergic reaction in the user) contamination may be kept very minimal. Due to the concept of direct incorporation of fibers under certain conditions adjustable by process control, no additional material (such as glue or the like) needs to be introduced in the process for interconnecting the fibers. This results in very low contamination of the fabric.

In an embodiment at least part (in particular at least 10%, more in particular at least 20%) of the fibers are integrally consolidated at the consolidation location. In the context of the present application, the term "merging" may particularly denote the integral interconnection of different fibers at the respective merging locations, which results in the formation of one integrally connected fiber structure composed of previously separated fiber preforms. Merging can be expressed as establishing fiber-fiber connections during the coagulation of one, some, or all of the merged fibers. Interconnected fibers can be strongly adhered to each other at the various merging locations without the need for different additional materials (eg, separate adhesives) to form a common structure. Separation of consolidated fibers may require disruption of the fiber network or components thereof. According to the described embodiments, nonwoven cellulosic fiber webs are provided in which some or all of the fibers are integrally connected to each other by merging. The incorporation can be triggered by corresponding control of the process parameters of the method of manufacturing the nonwoven cellulosic fiber web. Specifically, in the lyocell spinning that has not yet been in the state of precipitated solid fibers Coagulation of these filaments can be triggered (or at least completed) after the first contact between the filaments of the silk solution. Thus, the interaction between these filaments (while still in the solution phase, and then or thereafter transforming them into the solid phase by coacervation) allows for proper tuning of the incorporation characteristics. The degree of incorporation is a powerful parameter that can be used to fine-tune the properties of the fabricated fabric. Specifically, the greater the mechanical stability of the network, the higher the density of merging sites. By virtue of the non-uniform distribution of the merging locations over the volume of the fabric, it is also possible to adjust areas of high mechanical stability and other areas of low mechanical stability. For example, the separation of the fabric into individual components can occur locally in precisely defined areas of mechanical weakness with a small number of merged locations. In a preferred embodiment, merging between fibers can be triggered by bringing different fiber preforms in direct contact with each other in the form of a lyocell spinning solution prior to coagulation. With this coacervation process, a single material co-precipitation of fibers is performed to form merged sites.

In an embodiment, the merging point or location is composed of the same material as the merging fibers. Thus, merging sites can be formed by cellulosic material produced directly from coacervation of the lyocell spinning solution. Not only does this make it unnecessary to separately provide fiber connecting materials such as adhesives or adhesives, but it also keeps the fabric clean and made from a single material. The formation of fibers with non-circular cross-sections and the formation of interconnected fibers by merging can be accomplished by a single common process. The reason for this is that the formation of coalescing sites between fibers (such as coalescing points or lines) and the formation of fibers with cross-sections that deviate from a perfect circular diameter can both be achieved by spinning in the lyocell spinning solution before coagulation is complete. This is achieved by applying a mechanical force to the filament. However, the filaments of the lyocell spinning solution may be mechanically affected while they are still in the liquid phase. descriptively Said, on the one hand, the application of mechanical pressure to the filaments of the still liquid or viscous (usually in a honey-like consistency) lyocell spinning solution can promote the deformation of cylindrical filaments into (e.g. oval (especially oval) ) non-circular cross-sectional shape, thereby reducing the roundness. At the same time, applying this mechanical pressure on the filaments while they are still a liquid or viscous lyocell spinning solution and bringing them into physical contact with each other triggers the formation of coalescing sites between the fibers upon coagulation.

In an embodiment, the different ones of the fibers are at least partially located in different distinguishable (ie, exhibiting visible separation or interface regions between the layers) layers. For example, different mechanical properties between layers and at the interfaces between layers can be adjusted by individual adjustment of the roundness value of the fibers of each layer.

More specifically, the fibers of the different layers are integrally merged at at least one merge location between the layers. Thus, different ones of fibers at least partially located in different distinguishable layers (which may be the same or may be different with respect to one or more parameters, such as merging factor, fiber thickness, etc.) may be integrally connected at at least one merging location . For example, two (or more) different layers of fabric can be formed by arranging two (or more) nozzles in succession with orifices through which lyocell spinning solution is extruded for Agglomeration and fiber formation. When this configuration is combined with a mobile fiber support unit such as a conveyor belt with a fiber receiving surface, the first layer of fibers is formed on the fiber support unit by the first spray nozzle, and when the mobile fiber support unit reaches the second In the position of the second nozzle, the second nozzle forms the second layer of fibers on the first layer. The process parameters of this method can be adjusted such that a merge point is formed between the first layer and the second layer. Specifically, the second layer of fibers being formed has not yet been fully cured or solidified by coagulation, possibly for example There is still an outer skin or surface area that is still in the liquid lyocell solution phase and not yet in a fully cured solid state. When such pre-fiber structures come into contact with each other and are then fully solidified into a solid fiber state, this results in the formation of two merged fibers at the interface between the different layers. The higher the number of merging locations, the higher the stability of the interconnection between fabric layers. Thus, controlled incorporation allows control over the stiffness of the connections between the fabric layers. For example, consolidation can be controlled by adjusting the degree of solidification or coagulation before the pre-fibrous structure of each layer reaches the fibrous underlying layer or the fibrous support plate on the pre-fibrous structure. By merging fibers of different layers at the interface therebetween, undesired separation of the layers can be prevented. In the absence of merging points between layers, it is possible to delaminate one layer of fibers from another. According to an exemplary embodiment of the present invention, the degree of adhesion between fibers and/or between layers can be gradually adjusted between "un-incorporated fibers or layers" and "fully-incorporated fibers or layers". As a result, the partial adhesion, especially between the different layers, can be controlled and adjusted to functionalize the fabric of products manufactured on the basis of the fabric. For example, packaging can be made using such (particularly multi-layer) fabrics that provide light adhesion so that the packaged product can be properly handled through its weakly adhered components.

In order to determine the aforementioned incorporation factor of the fabric (which can also be expressed as the area incorporation factor), the following determination procedure can be carried out: A square sample of the fabric can be analyzed optically. A circle is drawn around each merged location of fibers intersecting at least one diagonal of the square sample, the circle having a diameter that must remain completely inside the square sample. The size of the circle is determined such that the circle encompasses the merged area between the merged fibers. Calculate the arithmetic mean of the diameters of the measured circles. The pooling factor is calculated as the mean diameter value of a square sample versus the diagonal The ratio between the lengths and can be expressed as a percentage.

In an embodiment, at least some of the fibers are twisted. Twisting fibers is a more powerful tool for engineering the mechanical strength of fiber networks. For example, twisted fibers may have higher mechanical stability than perfectly straight fibers. Likewise, the formation of twisted groups of fibers (for example, twisted combined fibers) can significantly increase the mechanical stability of the fabric in a similar manner, because a rope of twisted filaments has a significantly higher mechanical stability than a corresponding number of monofilaments. stability. For example, twisted fibers can be produced by spinning or spinning the filaments of the lyocell spinning solution during the drawing stage (ie, prior to coagulation or settling). In particular the application of vorticity, ie the turbulent flow around the filaments of the lyocell spinning solution prior to coagulation, can be used to form twisted fibers.

In an embodiment, the fibers are anisotropically aligned within the fabric to generally define at least one preferential alignment direction along which a greater portion of the fibers are aligned compared to other directions. In such embodiments, fiber shape adjustments may be made to a group of fibers or all fibers of the fabric to deviate from a circular cross-section so that when the fibers are deposited on the fibrous support elements, they generally or preferably lie along one or Multiple principal directions are aligned since their preferred bending axes are determined by the deviation of the fillets of the individual fibers. By taking this measure, a certain degree of order can be introduced in the fabric which results in the non-isotripic nature of the fabricated fabric.

In an embodiment, adjusting the process parameters includes applying a force to the filaments of the lyocell spinning solution before coagulation is complete. Descriptively, when a compressive force is applied to the viscous and thus still flowable filaments of the lyocell spinning solution prior to conversion to the solid phase, the filaments can be deformed from, for example, a cylindrical cross-sectional shape to For example an oval (especially elliptical) cross-sectional shape. Fiber deforming forces may be applied in a direction perpendicular to the longitudinal extension of the fiber or fiber portion under analysis. When coagulation is performed while the filaments of the lyocell spinning solution are in this deformed shape, fibers with a circularity of less than 1 are obtained.

In an embodiment, the force is applied by directing a forming fluid (which may be a liquid and/or a gas) to the filaments of the lyocell spinning solution before coagulation is complete. This shaping fluid may be a shaping gas (such as air) or a shaping liquid (such as water). When using forming gas, precisely definable mechanical forces are applied to the not yet coagulated filaments without initiating coagulation. When forming liquids are used, precisely definable mechanical forces also apply to the not yet coagulated filaments, which at the same time also trigger coagulation by diluting the lyocell spinning solution with a (in particular aqueous) liquid. In such embodiments, deformation and coagulation can occur simultaneously.

In embodiments, the pressure increase referred to by the gas or liquid (ie, fluid) streams may be configured such that each fluid stream is antiparallel at a certain location with the forming fiber interposed therebetween. As a result, a localized asymmetrical pressure increase occurs which affects the fibres. At the same time, this phenomenon does not further affect the process of fabricating fibers.

In an embodiment, at least some of the orifices are non-circular, in particular oval (in particular elliptical) or polygonal. Preferably, the openings in the ejection plates of the fiber forming units defining the orifices may have substantially the same roundness as the fibers composed of the precipitated lyocell spinning solution ejected through these individual orifices ( Especially the shape of not more than 90%). In one embodiment, the first portion of the orifice has a circular opening and the second portion of the orifice has a non-circular opening. Therefore, the shape design of the orifice also allows to define to some extent The fabricated fiber shape.

In an embodiment, adjusting the process parameters for adjusting the merging includes forming at least a partial merging location after the lyocell spinning solution has exited the orifice and before the lyocell spinning solution reaches the fiber support unit. This can be achieved, for example, by triggering interactions between strands of lyocell spinning solution extruded through different orifices when moving downwards. For example, the air flow can be adjusted in intensity and direction so that the different strands or filaments of the (not yet fully coagulated) spinning solution are forced to interact with each other in the transverse direction before reaching the fiber support unit. The gas flow can also be operated near or in a turbulent state to facilitate interaction between the various preforms of fibers. Thus, prior to agglomeration, individual preforms of fibers may contact each other, thereby forming a coalescing site.

In an embodiment, adjusting the process parameters for adjusting the consolidation comprises forming at least a partial consolidation site after the lyocell spinning solution reaches the fiber support unit by triggering at least partial fiber coalescence when deposited on the fiber support unit . In such an embodiment, the coagulation procedure (which can be adjusted by corresponding operation of the coagulation unit, in particular by correspondingly adjusting the properties of the coagulation fluid and the supply location) can be deliberately delayed. More specifically, the coagulation procedure can be delayed until the spinning solution has reached the fiber support plate. In such an embodiment, still prior to coagulation, a preform of fibers is deposited on a fiber support plate, thereby in turn contacting other preforms of fibers prior to coagulation. The spinning solutions of different strands or preforms can thus be forced to flow into contact with each other and coagulation can only be triggered or completed thereafter. Thus, after initial contact between different fiber preforms that are still in a non-agglomerated Gathering is an effective measure to form a merged position.

In an embodiment, adjusting the process parameters for adjusting the merging includes sequentially disposing a plurality of spray nozzles having orifices along the movable fiber support unit, depositing a first layer of fibers on the fiber support unit, and A second layer of fibers is deposited on the first layer before at least a portion of the fibers at the interface have completed agglomeration. For the individual layers to be formed, the process parameters for operating the corresponding injection nozzles can be adjusted in order to obtain a layer-specific cohesion behavior. The layer-specific cohesion behavior of different layers can be adjusted such that merging sites are formed within the respective layer and preferably between adjacent layers. More specifically, process control can be adjusted to form a coalescence site between two adjacent layers by promoting the coagulation of the two layers only after the initial contact between the spinning solutions associated with the different layers.

In an embodiment, the method additionally comprises further processing the fibers and/or fabric after collection on the fiber support unit, but preferably still in situ forming a non-woven cellulosic fiber fabric with endless fibers. Such in-situ processes may be those performed before the fabricated (particularly substantially endless) fabrics are stored (eg rolled up by a winder) for transport to the product manufacturing destination. For example, such further processing may involve hydroentanglement. Hydroentanglement can be expressed as the bonding process of wet or dry fiber webs, and the resulting bonded fabric is a non-woven fabric. Hydroentangling can use fine high pressure water jets that penetrate the fiber web, hit fiber support elements (particularly conveyor belts) and bounce off causing fiber entanglement. The corresponding compression of the fabric can make the fabric more compact and mechanically more stable. In addition to or alternatively to hydroentanglement, the fibers may be steamed with pressurized steam. Additionally or alternatively, such further or post-processing may involve needling the manufactured fabric. Needling systems can be used to bond knitting Fibers of objects or webs. As the needles pass through the web, some of the fibers are forced through the web, leaving the fibers behind when the needles are withdrawn to produce a needled fabric. If enough fibers are properly displaced, the web can be transformed into a fabric by the consolidation effect of these fiber plugs. Yet another further processing or post-treatment of the web or fabric is the impregnation treatment. Impregnation of the network of endless fibers may involve the application of one or more chemicals (eg, softeners, hydrophobic agents, antistatic agents, etc.) to the fabric. Yet another further processing is calendering. Calendering can be denoted as a process for treating fabrics, and calenders can be used to smooth, coat, and/or compress fabrics.

Nonwoven cellulosic fiber fabrics according to exemplary embodiments of the present invention may also be combined with one or more other materials (eg, in situ or in a subsequent process) to form composites according to exemplary embodiments of the present invention. Exemplary materials that can be combined with the fabrics used to form such composites can be selected from the group comprising, but not limited to, the following materials or combinations thereof: fluff pulp, fiber suspensions, wet-laid nonwovens, Airlaid nonwovens, spunbond, meltblown, carded spunlaced, or needlepunched, or other sheet-like structures made of various materials. In an embodiment, the connection between different materials may be performed by (but not limited to) one or a combination of the following processes: merging, hydroentanglement, needle punching, hydrogen bonding, thermal bonding, gluing through adhesives, laminating, and/or calendering.

In the following, exemplary advantageous products comprising or using nonwoven cellulosic fiber fabrics according to exemplary embodiments of the present invention are summarized: Web (100% cellulosic fiber web, or for example comprising two or more fibers or consisting of two or more A network composed of various fibers, or chemically modified fibers, or with Specific uses of fibers incorporating materials such as antimicrobial materials, ion exchange materials, activated carbon, nanoparticles, lotions, medicaments or flame retardants, or bicomponent fibers may be as follows: Exemplary according to the present invention Nonwoven cellulosic fiber fabrics of exemplary embodiments can be used to make wipes such as baby wipes, kitchen wipes, wet wipes, cosmetic wipes, hygiene wipes, medical wipes, cleaning wipes, polishing wipes (automotive household, furniture), dust wipes, industrial wipes, dust collector wipes, mop wipes.

Nonwoven cellulosic fiber fabrics according to exemplary embodiments of the present invention may also be used in the manufacture of filters. For example, such filters may be air filters, HVAC, air conditioning filters, flue gas filters, liquid filters, coffee filters, tea bags, coffee bags, food filters, water purification filters, blood filters, Cigarette Filters, Cabin Filters, Oil Filters, Cartridge Filters, Vacuum Filters, Vacuum Cleaner Filter Bags, Dust Filters, Hydraulic Filters, Kitchen Filters, Fan Filters, Moisture Exchange Filters, Pollen Filters, HEVAC/HEPA/ULPA filters, beer filters, milk filters, liquid coolant filters, and juice filters.

In yet another embodiment, nonwoven cellulosic fiber webs can be used in the manufacture of absorbent hygiene products. Examples are acquisition layers, hygienic breathable fabrics (coverstock), absorbent coverings, distribution layers, sanitary pads, coverings, back panels, leg cuffs, flushable products, pads, nursing pads, disposable underpants, Training pants, face masks, beauty masks, makeup removal pads, towels, diapers, and washer dryer sheets for releasing active ingredients such as textile softeners.

In yet another embodiment, the nonwoven cellulosic fiber fabric can be used in the manufacture of products for medical applications. Such medical application products can be, for example, disposable caps, gowns, masks and shoe covers, wound care products, sterile packaging products, breathable textile products for healthcare, dressing materials, one-way garments, dialysis products, nasal strips, dental boards Adhesives, disposable panties, drapes, wraps and wraps, sponges, dressings and wipes, bedding, transdermal drug delivery, shrouds, nursing pads, procedure packs, heating packs, ostomy bag liners, Fixed patches, and incubator pads.

In yet another embodiment, nonwoven cellulosic fiber fabrics can be used to make geotextiles. This can involve crop production protection mulch, felt, water purification, irrigation control, asphalt mulch, soil stabilization, drainage, sedimentation and erosion control, pond liners, impregnated bases, drain liners, ground stabilization, pit liners, Seed blankets, weed control fabrics, greenhouse shades, root bags, and biodegradable plant pots. Nonwoven cellulosic fiber webs can also be used in plant foils (for example to provide light and/or mechanical protection to plants, and/or to provide manure or seeds to plants or soil).

In another embodiment, nonwoven cellulosic fiber webs can be used in the manufacture of garments. For example, linings, clothing insulation and protection, handbag components, shoe components, belt liners, industrial hats/shoes, disposable work clothes, clothing and shoe bags, and thermal insulation can be manufactured on the basis of this fabric.

In yet another embodiment, nonwoven cellulosic fiber fabrics can be used to manufacture products for construction technology. For example, the fabric can be used for roofing and tile underlayment, slate underlayment, thermal and acoustic insulation, house wrap, plasterboard facing, pipe wrapping, concrete molding floors, foundations and ground stabilization, vertical drainage, decking, roofing felts, noise reduction, reinforcement, sealing materials, and damping materials (mechanical).

In yet another embodiment, the nonwoven cellulosic fiber fabric can be used in the manufacture of automotive products. Examples are cabin filters, boot liners, racks, heat shields, shelf trim, molded hood liners, boot sole coverings, oil filters, headliners, rear racks, upholstery fabrics, airbags, Muffler mats, insulation, car covers, underpadding, car floor mats, tapes, backings and tufted carpets, seat covers, door trims, needle punched carpets, and car carpet backings.

Another field of application for fabrics made in accordance with exemplary embodiments of the present invention is home furnishing items such as furniture, structures, arm and back insulation, cushion upholstery, dust covers, padding, seam reinforcement, edge trim, Bed frame structures, quilt backing, box springs, mattress pad components, mattress covers, curtains, wall coverings, carpet backing, lamp shades, mattress components, spring insulators, seals, pillow jacquards, and beds Cushion Jacquard.

In yet another embodiment, the nonwoven cellulosic fiber fabric can be used in the manufacture of industrial products. This can involve electronics, floppy disk liners, cable insulation, abrasives, insulating tapes, conveyor belts, noise absorbing layers, air conditioners, battery separators, acid systems, anti-slip felt decontamination machines, food wrapping, tapes, sausage casings , cheese casings, artificial leather, boom and sock, and paper felt.

Nonwoven cellulosic fiber fabrics according to exemplary embodiments of the present invention are also suitable for use in the manufacture of leisure and travel related products. Examples of such applications are sleeping bags, tents, luggage, handbags, shopping bags, airline headrests, CD holders Cases, pillowcases, and sandwich packaging.

Yet another field of application of exemplary embodiments of the present invention relates to school and office products. For example, mention should be made of book covers, mailing envelopes, maps, signs and pennants, towels, and flags.

The illustrations in the figures are schematic. In different figures, similar or identical elements or features are provided with the same reference signs.

FIG. 1 depicts an apparatus 100 for making a nonwoven cellulosic fiber fabric 102 formed directly from a lyocell spinning solution 104, according to an exemplary embodiment of the present invention. Lyocell spinning solution 104 is at least partially coagulated by coagulation fluid 106 to be converted into partially formed cellulose fibers 108 . With the device 100, the Lyocell solution-jet spinning method according to an exemplary embodiment of the present invention can be performed. In the context of the present application, the term "lyocell solution-jet spinning" may specifically cover processes that result in discrete lengths of substantially endless filaments or fibers 108, or mixtures of discrete lengths of endless filaments and fibers . As further described below, according to an exemplary embodiment of the present invention, there are provided nozzles each having an orifice 126 through which the cellulose solution or lyocell spinning solution 104 passes together with a gas stream (or gas flow) 146 Extruded for use in making nonwoven cellulosic fiber web 102.

As can be seen from FIG. 1 , wood pulp 110 , other cellulosic raw materials, etc. can be supplied to a storage tank 114 via a metering unit 113 . Water from the water container 112 is also supplied to the storage tank 114 via the metering unit 113 . Thus, under the control of control unit 140 described in further detail below, metering unit 113 may define the relative amounts of water and wood pulp 110 to be supplied to storage tank 114 . The solvent contained in the solvent container 116 (such as N-methyl-morpholine N-oxide; NMMO) can be stored in the concentration unit 118, and then can be mixed with water and wood pulp 110, or other cellulose-based raw materials in a determinable relative amount in a mixing unit 119. The mixing unit 119 can also be controlled by the control unit 140 . Thus, the water-wood pulp 110 medium is dissolved in the concentrated solvent of the dissolving unit 120 in an adjustable relative amount to obtain a lyocell spinning solution 104 . The aqueous lyocell spinning solution 104 may be a honey viscous medium composed of cellulose (eg, 5% to 15% by mass) including wood pulp 110 and a solvent (eg, 85% to 95% by mass).

The lyocell spinning solution 104 is sent to a fiber forming unit 124 (which may be implemented as or may comprise a plurality of spin bundles or jet nozzles 122). For example, the number of orifices 126 of the injection nozzle 122 may be greater than 50, in particular greater than 100. In one embodiment, all orifices 126 of a fiber forming unit 124 (which may include a plurality of spinning nozzles or jet nozzles 122) may have the same size and/or shape. Alternatively, different orifices 126 of one spray nozzle 122 and/or orifices 126 of different spray nozzles 122 (which may be arranged consecutively for forming a multi-layer fabric) may be different in size and/or shape.

As the lyocell spinning solution 104 passes through the orifice 126 of the spray nozzle 122, it is divided into a plurality of parallel strands of the lyocell spinning solution 104. Vertically oriented airflow (i.e., oriented substantially parallel to the spinning direction) forces the lyocell spinning solution 104 to convert into longer and finer strands, which can be controlled by the control unit 140 Change the process conditions to adjust the stock. The airflow may accelerate the lyocell spinning solution 104 along at least a portion of its path from the orifice 126 to the fiber support unit 132 .

When the lyocell spinning solution 104 moves through the nozzle 122 and further to The long, thin strands of lyocell spinning solution 104 interact with the non-solvent coagulating fluid 106 while down. Condensed fluid 106 is advantageously embodied as a vapor mist, such as water mist. Process-related properties of the coagulation fluid 106 are controlled by one or more coagulation units 128 to provide adjustable properties for the coagulation fluid 106 . The coagulation unit 128 is sequentially controlled by the control unit 140 . Preferably, each agglomeration unit 128 is positioned between each nozzle or orifice 126 for individually adjusting the properties of each layer of the fabric 102 being produced. Preferably, each spray nozzle 122 may have two agglomeration units 128 configured, one on each side. Individual injection nozzles 122 can thus be provided with individual portions of the lyocell spinning solution 104 which can also be adjusted to have different controllable properties of the different layers of the manufacturing fabric 102 .

When interacting with the coagulation fluid 106 (such as water), the solvent concentration of the lyocell spinning solution 104 is reduced such that the cellulose of the coagulation fluid, such as wood pulp 110 (or other raw material), is at least partially coagulated into long and thin Cellulose fibers 108 (which may still contain residual solvent and water).

During or after the initial formation of individual cellulose fibers 108 from the extruded lyocell spinning solution 104, the cellulose fibers 108 are deposited on a fiber support unit 132, which is here embodied as a conveyor. Cellulosic fibers 108 form nonwoven cellulosic fiber web 102 (only schematically depicted in FIG. 1 ). The nonwoven cellulosic fiber web 102 is composed of continuous and substantially endless filaments or fibers 108 .

Although not shown in FIG. 1 , the solvent of the lyocell spinning solution 104 removed by coagulation in the coagulation unit 128 and washed in the washing unit 180 may be at least partially recycled.

While conveying along the fiber support unit 132, the non-woven cellulosic fiber web 102 may be washed by a washing unit 180 supplied with washing liquid to remove residual solvent, and then may be dried. It can be further processed by an optional but advantageous further processing unit 134 . For example, such further processing may involve hydroentanglement, needle impregnation, impregnation, steaming with pressurized steam, calendering, and the like.

The fiber support unit 132 can also convey the nonwoven cellulosic fiber web 102 to a coiler 136, on which the nonwoven cellulosic fiber web 102 can be collected as a substantially endless sheet. The nonwoven cellulosic fiber web 102 may then be shipped as a roll-good to entities that manufacture products based on the nonwoven cellulosic fiber web 102 , such as wipes or textiles.

As shown in FIG. 1 , the process can be controlled by a control unit 140 (such as a processor, part of a processor, or a plurality of processors). The control unit 140 is configured for controlling the operation of the various units shown in FIG. , dissolving unit 120, washing unit 180 and the like. Thus, the control unit 140 (e.g., by executing computer-executable code, and/or by executing user-defined control commands) can precisely and flexibly define the process parameters according to which the nonwoven cellulose Fabric 102. Design parameters in this context are the gas flow along the orifice 126, the properties of the coalescing fluid 106, the drive speed of the fiber support unit 132, the composition of the lyocell spinning solution 104, temperature and/or pressure, and the like. Additional design parameters (which are adjustable in order to adjust the properties of the nonwoven cellulosic fiber web 102) are the number of orifices 126, and/or mutual distance, and/or geometric configuration, lyocell spinning solution 104 chemical composition and concentration. Accordingly, the properties of the nonwoven cellulosic fiber web 102 can be appropriately adjusted as described below. Such adjustable properties (see detailed description below) may relate to one or more of the following properties: diameter and/or diameter distribution of fibers 108, amount and/or area of coalescence between fibers 108, purity level of fibers 108, Multilayer fabric 102 properties, optical properties of fabric 102, fluid retention and/or fluid release properties of fabric 102, mechanical stability of fabric 102, smoothness of fabric 102 surface, cross-sectional shape of fibers 108, and the like.

Although not shown, each spin jet nozzle 122 may include a polymer solution inlet through which the lyocell spinning solution 104 is supplied to the jet nozzle 122 . Via the air inlet, an airflow 146 can be applied to the lyocell spinning solution 104 . Starting from the interaction chamber inside the jet nozzle 122 and bounded by the jet nozzle housing, the lyocell spinning solution 104 is moved or accelerated downward through each orifice 126 (by the air flow 146 pulling the lyocell spinning solution 104 downward). ), and is laterally reduced under the influence of airflow 146, so that when lyocell spinning solution 104 moves downward in the environment of coagulation fluid 106 together with airflow 146, continuously thinning cellulose filaments or cellulose are formed Fiber 108.

Thus, the process involved in the manufacturing method described with reference to FIG. 1 may include shaping a lyocell spinning solution 104 (which may also be denoted as a cellulose solution) to form liquid strands or potential filaments, the liquid strands or potential filaments The filaments are drawn by the gas flow 146 and are significantly reduced in diameter and increased in length. Partial coagulation of latent filaments or fibers 108 (or preforms thereof) by coagulation fluid 106 may also be involved prior to or during web formation on fiber support unit 132 . The filaments or fibers 108 are formed into a web 102, washed, dried, and optionally to be further processed (see further processing unit 134). For example, the filaments or fibers 108 may be collected, for example, on a rotating drum or belt, thereby forming a web.

Due to the described manufacturing process, in particular the choice of solvent used, the fibers 108 have a copper content of less than 5 ppm and/or have a nickel content of less than 2 ppm. This advantageously increases the purity of the fabric 102 .

Lyocell solution-blown webs (i.e., nonwoven cellulosic fiber fabric 102) according to exemplary embodiments of the present invention preferably exhibit one or more of the following properties:

(i) The dry weight of the net is 5 to 300g/m ² , preferably 10-80g/m ²

(ii) according to standard WSP120.6 or DIN29073 respectively (in particular in the latest version valid at the priority date of this patent application), the thickness of the mesh is 0.05 to 10.0 mm, preferably 0.1 to 2.5 mm

(iii) according to EN29073-3 or ISO9073-3 respectively (in particular in the latest version valid at the priority date of this patent application), the specific strength of the mesh of MD is in the range of 0.1 to 3.0 Nm ² /g, preferably 0.4 to 2.3 Nm ² /g

(iv) according to EN29073-3 or ISO9073-3 respectively (in particular in the latest version valid at the priority date of this patent application), the average elongation of the net is in the range of 0.5 to 100%, preferably 4 to 50%

(v) The MD/CD strength ratio of the mesh is 1 to 12

(vi) According to DIN 53814 (in particular in the latest version valid at the priority date of this patent application), the water retention of the net is 1 to 250%, preferably 30 to 150%

(vii) According to DIN 53923 (in particular in the latest edition valid at the priority date of this patent application), the water retention capacity of the net is in the range of 90 to 2000%, compared to The best is 400 to 1100%

(viii) According to the decomposition standard EN 15587-2 and the ICP-MS standard EN 17294-2, the metal residue level of copper content below 5ppm and nickel content below 2ppm is especially measured.

Optimally, the lyocell solution-spun web exhibits all of said properties (i) to (viii) mentioned above.

As noted, the process for producing the nonwoven cellulosic fiber web 102 preferably includes the following:

(a) Extrude a solution comprising cellulose dissolved in NMMO (see reference numeral 104) through at least one orifice 126 of a spray nozzle 122 to form filaments of lyocell spinning solution 104

(b) drawing said filaments of lyocell spinning solution 104 by means of air flow (see reference numeral 146)

(c) contacting said filaments with a steam mist (see reference numeral 106 ), preferably containing water, to at least partially settle said fibers 108 . Accordingly, prior to forming the web or nonwoven cellulosic fiber web 102, the filaments or fibers 108 are at least partially deposited

(d) collecting and depositing the filaments or fibers 108 to form a web or non-woven cellulosic fiber fabric 102

(e) Remove solvent in wash line (see wash unit 180)

(f) Joining optionally via hydroentanglement, needle sticking, etc. (see further processing unit 134)

(g) drying and winding.

can be achieved by merging, entanglement, hydrogen bonding, physical junctions such as hydroentanglement Knots or needles), and/or chemical bonding to combine the components of the nonwoven cellulosic fiber fabric 102.

For further processing, the nonwoven cellulosic fiber web 102 may be combined with one or more layers of the same and/or other materials, such as (not shown) layers of synthetic polymers, cellulose fluff pulp, cellulose, or synthetic polymers Nonwoven webs of fibers, bicomponent fibers, cellulosic pulp webs such as air-laid or wet-laid pulps, high-strength fiber webs or fabrics, hydrophobic materials, high-performance fibers such as heat-resistant or flame-retardant materials ), layers imparting altered mechanical properties to the final product (such as polypropylene or polyester layers), biodegradable materials (eg, films, fibers, or webs from polylactic acid), and/or high bulk materials.

It is also possible to combine several distinguishable layers of the nonwoven cellulosic fiber web 102 , see eg FIG. 7 .

Nonwoven cellulosic fiber web 102 may consist essentially only of cellulose. Alternatively, nonwoven cellulosic fiber web 102 may comprise a mixture of cellulose and one or more other fibrous materials. Additionally, the nonwoven cellulosic fiber web 102 may comprise a bicomponent fiber material. The fibrous material in nonwoven cellulosic fiber web 102 may at least partially comprise a modifying substance. The modifying substance may be selected from the group consisting of, for example, polymeric resins, inorganic resins, inorganic pigments, antimicrobial products, nanoparticles, lotions, flame retardant products, absorption modifying additives such as superabsorbent resins ), ion exchange resins, carbon compounds (such as activated carbon, graphite, conductive carbon), X-ray contrast substances, luminescent pigments, and dyes.

Finally, a cellulosic nonwoven web or nonwoven cellulosic fiber web 102 fabricated directly from a lyocell spinning solution 104 allows the opportunity to achieve value-added web properties not possible via the short fiber route. This includes the opportunity to form a uniform lightweight web, manufacture microfiber products, and manufacture continuous filaments or fibers 108 that form the web. Furthermore, compared to staple fiber webs, several manufacturing steps are no longer required. Furthermore, the nonwoven cellulosic fiber fabric 102 according to an exemplary embodiment of the present invention is biodegradable and manufactured from sustainably sourced raw materials (ie, wood pulp 110, etc.). In addition, it has advantages in terms of purity and absorbency. In addition, it has adjustable mechanical strength, rigidity, and softness. In addition, the nonwoven cellulose fiber fabric 102 according to the exemplary embodiment of the present invention can be manufactured with a low weight per unit area (eg, 10 to 30 g/m ² ). Very thin filaments with diameters as small as (or not exceeding) 5 μm, especially not larger than 3 μm, can be produced by this technique. In addition, the nonwoven cellulosic fiber fabric 102 according to exemplary embodiments of the present invention can be formed with various web aesthetics, for example, in a flat crispy film-like manner, in a paper-like manner, like), or in the form of soft flexible textile-like. By adjusting the process parameters of the process, the rigidity and mechanical rigidity, or the flexibility and softness of the nonwoven cellulose fiber fabric 102 can be adjusted more precisely. This can be adjusted, for example, by adjusting the number of merging locations, the number of layers, or by post-processing such as needling, hydroentangling, and/or calendering. It is particularly possible to manufacture nonwoven cellulosic fiber fabrics 102 with a relatively low basis weight as low as 10 g/m ² or lower to obtain very small diameters (e.g., as low as 3 to 5 μm, or lower) The filament or fiber 108 etc.

Figures 2, 3 and 4 show experimentally captured images of a nonwoven cellulose fiber fabric 102 according to an exemplary embodiment of the present invention, wherein the corresponding Process control accomplishes the combining of individual fibers 108 . The oval marks in FIGS. 2-4 show such merged regions where the plurality of fibers 108 are integrally connected to each other. At such merging points, two or more fibers 108 may interconnect to form a unitary structure.

Figures 5 and 6 show experimentally captured images of a non-woven cellulosic fiber fabric 102 (where swelling of the fibers 108 has been completed) according to an exemplary embodiment of the present invention, wherein Figure 5 shows the fiber fabric 102 in a dry, non-swollen state, Figure 6, however, shows the fibrous fabric 102 in a moist, swollen state. The diameter of the hole can be measured in the two states of Fig. 5 and Fig. 6, and can be compared with each other. When the average of 30 measurements was calculated, the pore size was measured to decrease to 47% of its original diameter by swelling of the fibers 108 in the aqueous medium.

2)。 7 shows an experimentally captured image of a non-woven cellulosic fiber fabric 102 according to an exemplary embodiment of the present invention, wherein two layers of fibers 108 are completed by a corresponding process design (i.e., a continuous configuration of multiple spinning nozzles). Formation of stacked layers 200 , 202 . In Fig. 7 two separate but connected layers 200, 202 are represented by horizontal lines. For example, n layers of fabric 102 (n

2).

A specific exemplary embodiment of the invention will be described in more detail below: FIG. 8 shows a schematic drawing which will be used to explain that when the roundness of the cross-section of the fiber 108 is adjusted to deviate from a circular cross-section, the definition of the fiber 108 can be facilitated. bending.

In order to explain the phenomenon, the fiber 108 is shown in FIG. 8 in a straight state with no force fee (upper image) and in a state where the fiber 108 is subjected to a bend (lower image). When the fiber 108 has a perfectly cylindrical cross-section, even a very small bend Bending forces may also cause fibers 108 to bend along unpredictable bending axes. Therefore, in practical applications it is impossible to predict or determine the direction along which a bundle of fibers 108 with a perfectly cylindrical cross-section will undergo bending. However, when the roundness of the fiber 108 significantly deviates from a value (that is, the cross-section of the fiber 108 deviates from a true circle, for example, the shape is oval (especially elliptical)), thereby defining a preferred bending axis, along which The shaft can be bent in an easier way (or with less force) than in a direction perpendicular to it. For example, fibers 108 having an oval-elliptical cross-section may be bent with less force having a shorter minor axis as the bend line than with a longer major axis as the bend line.

Applying the described phenomenon to the fiber design of a fabric 102 according to an exemplary embodiment of the present invention, designing the fibers 108 of such a fabric 102 with a circular cross-section allows predictably defining the preferred bending axis of the fibers 108 . When the filaments of lyocell spinning solution 104 are deposited on fiber support unit 132 to form fibers 108 by coagulation, they will be accommodated along the fibers of fiber support unit 132 in a predictable and not only statistical manner. Surfaces, arranged in a certain order. Thus, by defining the cross-section of fibers 108 to deviate from circular symmetric geometry, the mechanical properties of fabric 102 can be precisely defined. Thus, predictability can be introduced in nonwoven cellulosic fibrous web 102 due to the pronounced non-circular out-of-roundness definition of fibers 108 . Finally, adjusting the deviation of at least some of the fibers 108 of the nonwoven cellulosic fiber web 102 according to an exemplary embodiment of the present invention from the cylindrical geometry, with corresponding adjustments in the manufacturing process, allows for precise definition of the mechanical properties of the web 102, particularly is to allow obtaining a fabric 102 with high mechanical strength.

Figure 9 shows nonwoven cellulose fibers according to an exemplary embodiment of the present invention An experimentally captured image of web 102 depicts fibers 108 having a cross-sectional shape that deviates from a circle.

Preferably, along at least a portion of the fibers 108 extending longitudinally, at least 10% of the fibers 108 have a non-circular cross-sectional shape that is not greater than 50% circular. Due to this strong deviation of a significant subset of fibers 108 from cylindrical geometry, a degree of regularity can be defined in fabric 102 . This allows fine-tuning of the mechanical properties of the obtained fabric 102 . On the basis of the non-woven standard WSP90.3, the smoothness of the fabric 102 measured by the "fabric hand tester" can be freely adjusted in a wide range between 2mNm ² /g and 70mNm ² /g, because by at least some The out-of-round roundness design of the fibers 108 can precisely define the desired mechanical strength.

Due to the manufacturing process of fabric 102 described above with reference to FIG. 1 , fibers 108 have only a very small copper content of less than 5 ppm and/or have only a very small nickel content of less than 2 ppm. Therefore, the fabric 102 can be manufactured with very little heavy metal contamination, ensuring the biocompatibility of the fabric 102 and preventing allergic reactions when the fabric 102 is in physical contact with human skin.

FIG. 10 shows an experimentally captured image of a nonwoven cellulosic fiber web 102 in which fibers 108 having cross-sectional shapes that deviate from circular are partially twisted, according to an exemplary embodiment of the present invention.

In the embodiment of FIG. 10, some fibers 108 are twisted. Thus, these fibers 108 extend along at least part of their longitudinal direction forming a slightly helical structure. This fiber twisting imparts mechanical strength to the resulting nonwoven cellulosic fiber web 102 while allowing some adjustment of the elasticity of the web 100 . Specifically, with a deviation from one roundness, twisted, and in the merged position The combination of fibers 108 merging with each other at 204 provides fabric 102 with some degree of flexibility.

FIG. 11 shows an experimentally captured image of a nonwoven cellulosic fiber fabric 102 consisting of three stacked layers 202 , 200 , 200 having different fiber 108 diameters according to another exemplary embodiment of the present invention. According to FIG. 11 , the intermediate sandwich layer 200 has a significantly smaller diameter of the fibers 108 than the upper and lower two outer layers 200 , 202 .

The multilayer fabric 102 shown in Figure 11 is particularly suitable for applications such as medical applications, agricultural textiles, and the like. For example, active substances can be stored in the inner layer 200, which exhibits high capillary action. The outer layers 200, 202 can be designed for rigidity and surface feel. This is advantageous for cleaning and medical applications. For agricultural applications, the fiber layer design can be specially configured according to evaporation properties and/or root penetration.

In another application, the multilayer fabric 102 shown in FIG. 11 can be used as a facial mask, where the middle layer 200 can have particularly pronounced fluid retention capabilities. The cover layers 200, 202 may be configured for tailoring fluid release properties. The diameter of the fibers 108 of each layer 200, 200, 202 can be used as a design parameter for tuning these functions.

Thus, the fibers 108 shown in FIG. 11 are located in three different distinguishable layers 200,202. The fibers 108 of the different layers 200 , 202 are integrally merged at a merge location 204 between the layers 200 , 202 . Furthermore, at least some of the fibers 108 are provided with a non-circular cross-section having a circularity of no greater than 90%, which provides a degree of order in the layers 200 , 202 and reinforces the fabric 102 .

12 shows how to calculate the value of the roundness of a fiber 108 having a cross-section deviating from a circular cross-section as the ratio between the radii of the inscribed circle 280 and the circumscribed circle 282 of the cross-section of the fiber 108 according to an exemplary embodiment of the present invention .

2r及纖維108的真圓度因此是約0.5或50%。為了比較，圓柱形纖維108滿足條件R=r，並且真圓度為1或100%。 The smallest circumscribed circle 282 is defined as the smallest circle that encloses the entire circularity profile of the cross-section of the fiber 108 depicted in FIG. 12 . The largest inscribed circle 280 is defined as the largest circle that inscribes the entire circularity profile of the cross-section of the fiber 108 depicted in FIG. 12 . In the context of the present application, roundness may be defined as the ratio between the radius r of the inscribed circle 280 divided by the radius R of the circumscribing surface 282 . Circularity can be expressed by the resulting percentage value. In this example, R

The roundness of 2r and fiber 108 is therefore about 0.5 or 50%. For comparison, the cylindrical fiber 108 satisfies the condition R=r and has a roundness of 1 or 100%.

13 shows a portion of an apparatus 100 for making a nonwoven cellulosic fiber web 102 consisting of two stacked layers 200 of endless cellulosic fibers 108, according to an exemplary embodiment of the present invention. , 202 composed of. The upstream spray nozzle 122 on the left hand side of FIG. 13 produces a layer 202 of fibers 108 in view of the movable fiber receiving surface of the conveyor belt fiber support unit 132 . A layer 200 of further fibers 108 is produced by the downstream injection nozzle 122 (on the right hand side in FIG. 13 ) and is attached to the upper main surface of the previously formed layer 202 , thereby obtaining a double layer 200 , 202 of the fabric 102 .

According to FIG. 13 , the control unit 140 (controlling the injection nozzles 122 and the agglomeration unit 128 ) is configured for adjusting the process parameters such that at least part of the fibers 108 are integrally merged at the merge location 204 between the layers 200 , 202 .

Although not shown in FIG. 13 , for example, by hydroentangling, needle-punching, and/or impregnation, further processing may be performed after collection on the fibrous support unit 132. Fiber 108 .

Referring again to the embodiment depicted in FIG. 13 , one or more additional nozzle bars or nozzles 122 may be provided and may be arranged consecutively along the conveying direction of the fiber support unit 132 . Multiple spray nozzles 122 may be configured such that additional layers 200 of fibers 108 may be deposited on top of previously formed layers 202 (preferably before the coagulation or curing process of layers 202 and/or fibers 108 of layers 200 is fully completed) , which triggers a merge. When the process parameters are properly adjusted, this may have a favorable effect on the properties of the multilayer fabric 102: a desired coalescence between the fibers 108 of the fabric 102 according to FIG. 13 may be triggered in order to further increase the mechanical stability of the fabric 102. In this context, merging may be support contact point adhesion of the filaments contacting the fibers 108 , in particular merging prior to completion of the coagulation process of one or both fibers 108 . For example, combining can be facilitated by increasing the contact pressure between two filaments of the lyocell spinning solution 104 to be combined by a fluid flow (eg, air or water flow). By taking this measure, the adhesion between the different filaments or fibers 108 of one of the layers 200, 202 on the one hand and/or the adhesion between the layers 200, 202 on the other hand can be increased.

According to the apparatus 100 of FIG. 13 (which is configured for the manufacture of a multilayer fabric 102), a number of process parameters are implemented which can be used to adjust the consolidation factor, design the shape and/or diameter of the fibers 108 and fiber layers 200, 202, or diameter distribution. This is a result of the sequential arrangement of multiple injection nozzles 122, each of which can be operated with individually adjustable process parameters. When the orifices 126 of the plurality of spray nozzles 122 are shaped differently and in a non-circular manner, the fabric 102 may also be formed having fibers 108 with cross-sections that deviate from circular. This fiber 108 can be Oval, oval, rectangular, triangular, polygonal, with sharp and/or rounded edges, etc.

For the device 100 according to Fig. 13, it is in particular possible to manufacture a fabric 102 consisting of at least two layers 200, 202, preferably more than two layers. By virtue of the definite layer separation of the multilayer fabric 102, the multilayer fabric 102 can later also be divided into different individual layers 200, 202 or different multilayer parts. According to an exemplary embodiment of the invention, the intralayer adhesion of the fibers 108 of one layer 200, 202 and the interlayer adhesion of the fibers 108 between adjacent layers 200, 202 (e.g., by merging and/or by creating contact by friction) may Adjust appropriately and individually. A corresponding individual control for each individual layer 200 , 202 may in particular be obtained when the process parameters are adjusted such that when one layer 200 of fibers 108 is placed on top of it, the coagulation or solidification of the fibers 108 of another layer 202 has been completed.

For example, adjusting process parameters for adjusting consolidation according to FIG. 13 includes sequentially disposing a plurality of spray nozzles 122 having orifices 126 along a movable fiber support unit 132 on which a first layer 202 of fibers 108 is deposited. , and before all of the fibers 108 at the interface between the layers 200, 202 have completed coagulation, a second layer 200 of fibers 108 is deposited on the first layer 202. Thus, different ones of the fibers 108 of the fabric 102 may be located in different identifiable layers 200 , 202 , but may be combined by forming a combining location 204 . In other words, the fibers 108 of the different layers 200 , 202 may be collectively merged at one or more merge locations 204 between the layers 200 , 202 .

FIG. 14 shows components of an apparatus 100 for manufacturing a nonwoven cellulosic fiber fabric 102 according to yet another exemplary embodiment of the present invention, wherein the process is controlled by a control unit 140 to trigger a non-circular out-of-roundness (by using the The formation of coalescing sites between fibers 108 of roundness (applying transverse forces to fibers 108 during coagulation).

More specifically, the spinning solution texturing unit 270 is provided in the apparatus 100 configured to apply texturing forces to the filaments of the lyocell spinning solution 104 before coagulation is complete. This deforming force can deform the filament from a circular cross-section to a non-circular cross-section. As can be seen in detail 274 , a portion of fabric 102 is shown prior to completion of coagulation of fibers 108 by applying a solution deforming force by directing forming fluid stream 272 to the filaments of lyocell spinning solution 104 before coagulation is complete. The forming fluid 272, which may be an air and/or liquid flow, is directed from the spin solution texturing unit 270 to the filaments of the lyocell spin solution 104 before the fibers 108 are deposited therefrom. Pressure applied by forming fluid 272 to the filaments of lyocell spinning solution 104 deforms the filaments from, for example, a temporally circular cross-sectional shape to an oval or flattened shape, as shown in detail 274 . When the pressure exerted by the forming fluid 272 on the filaments of the lyocell spinning solution 104 is maintained until coagulation or settling is complete, the fibers 108 will automatically form a corresponding shape having a non-circular cross-section. When the forming fluid 272 comprises or consists of water, the application of forming pressure may be synergistically combined with the coagulated precipitation of the fibers 108 from the lyocell spinning solution 104, at least in part, by the subsequent aqueous forming fluid 272. trigger.

FIG. 15 illustrates a component of an apparatus 100 for manufacturing a nonwoven cellulosic fiber fabric 102 having an orifice 126 shaped to form a Circularity The roundness of the fiber 108.

Additionally or alternatively according to the rules adopted in Fig. 14, for determining the texture If at least part of the fibers 108 of the object 102 have a circularity of less than 1, the orifice 126 of the injection nozzle 122 of FIG. 15 is provided with a non-circular shape. In the illustrated embodiment, alternating rows of elliptical orifices 126 are foreseen, either with respective major axes, or along a common alignment axis 236 (i.e., according to the horizontal direction of FIG. Orifices 126), or along a parallel alignment axis 238 (ie, according to the vertical direction of FIG. 15, compare even columns of orifices 126). However, it will be apparent to those having ordinary skill in the art that the illustrated pattern of orifices 126 is exemplary only, and that many other patterns of non-circular orifices 126 may be implemented in accordance with other exemplary embodiments of the present invention. .

16 shows a schematic view of a nonwoven cellulosic fiber web 102 according to an exemplary embodiment of the present invention, depicting fibers 108 having a cross-sectional shape that deviates from a circle, as a result, the fibers 108 are arranged or aligned substantially along a preferential direction 290 . In other words, the fibers 108 are anisotropically aligned within the fabric 102 to generally define a preferential alignment direction 290 along which a greater portion of the fibers 108 are aligned compared to other directions. According to FIG. 16 , several fibers 108 of the fabric 102 are shown, all of which have a non-circular elliptical cross-section. Thus, the fibers 108 are preferably bent about the alignment direction 290 when the fibers 108 are deposited on the fiber support unit 132 . It can be seen from FIG. 16 that some fibers 108 merge at merge location 204 prior to coagulation, while other fibers 108 cross each other at intersection location 264 without merging, ie, only experience mutual friction.

More generally, providing the non-woven cellulosic fiber web 102 with non-circular endless fibers 108 results in increased stiffness and uniformity. Although according to Each individual process of deposition of a fiber 108 on the fiber support unit 132 has a statistical effect, but a predictable preferred deposition direction of the fiber 108 can be defined by arranging at least part of the fiber 108 with a non-circular cross-section. By fabricating at least some of the fibers 108 with a sufficiently small degree of roundness, a corresponding increase in at least one of uniformity and stiffness can be obtained. This is particularly powerful for increasing the stability of the fabric 102 when simultaneously triggering coalescence between at least some of the fibers 108 . By adjusting the properties of the fibers 108 of the fabric 102 according to exemplary embodiments of the present invention, in terms of roundness value or cross-sectional shape, it is possible to functionalize the fabric 102 for a particular application. In particular, this allows the design of fabric 102 with higher mechanical strength for a given grammage, or lower grammage for a given mechanical strength. This enhanced mechanical stability can be obtained in one or two perpendicular directions in the plane of the fabric 102 corresponding to the fiber receiving plane of the fiber support unit 132 . Very advantageously, according to an exemplary embodiment of the present invention, such a fabric 102 can be produced according to the structure of a lyocell spinning solution, so that the obtained fabric 102 can be guaranteed to have very low contamination of heavy metal impurities. Thus, the obtained nonwoven cellulosic fiber web 102 has a very high purity, so that the obtained web 102 or the products manufactured based thereon are less likely to cause allergic reactions in users.

According to a preferred embodiment, one or more nozzle bars or nozzles 122 are implemented for producing filaments of the lyocell spinning solution 104, wherein the filaments are then drawn, crimped, and deposited on a fiber support on the fiber receiving surface of unit 132. During this drawing process and/or when the filaments of the not yet coagulated lyocell spinning solution 104 are deposited on the fiber support unit 132, Air vorticity or turbulence triggers or facilitates the formation of a merge location 204 between two or more fibers 108 .

This merging process may occur at various points during the condensation of the chemical process forming the endless fibers 108 . They can also be tuned at different intensities and can be facilitated using different media such as water or air. With corresponding adjustments, the cohesion and/or shaping of the filaments, as well as the adhesion at the contacting or merging locations 204, can be controlled. As a result, a wide variety of consolidation effects can be adjusted: on the one hand, a fabric 102 can be formed with a very low tendency to coalesce and stick; on the other hand, the process can be controlled so that an extremely strong consolidation is obtained, so that the fibers 108 lose their shape , and tend to present a surface-like membrane structure.

Statistical or stochastic processes may be involved during the deposition process of fibers 108 or their not-yet-coagulated preforms. This typically results in an arbitrary configuration of endless filaments or fibers 108 . Random orientation of the filaments of the fibers 108 may occur particularly when the conveying speed of the conveying device (ie, the fiber support unit 132 ) is significantly less than the speed of the filaments moving downward on the fiber receiving surface of the fiber support unit 132 . In other words, as the filaments move down on the fiber support unit 132, due to the reaction force applied to the filaments from the fiber support unit 132, non-predictable or pseudo-random deposition directions of the filaments or fibers 108 may occur. This phenomenon has been described above with reference to FIG. 8 .

However, as described above with reference to FIG. 8 , exemplary embodiments of the present invention can overcome the randomness of fibers 108 by arranging at least some of fibers 108 in conforming non-circular cross-sections having a circularity value of 90% or less. Such pure statistics of deposition behavior. When the fiber 108 deviates from the cylindrical section to a sufficient degree At different degrees, one or more principal deposition directions of fibers 108 or groups of fibers 108 may be defined for corresponding design and orientation, thereby increasing the uniformity and predictability of properties of fabric 102 . is descriptive and refers to the oval cross-section of fibers 108 that preferably bend or kink downward in the direction of the smaller cross-sectional dimension (i.e., along the minor axis of the ellipse) . Due to this phenomenon, the control over the cross-sectional shape of the fabricated fibers 108 deviates from the circular shape, allowing one or more preferential alignment directions of the fibers 108 in the fabric 102 to be defined.

In order to produce fibers 108 with a circularity of less than 90%, preferably less than 50%, pressure can be applied to the uncoagulated preform of fibers 108 by, for example, blowing air or generating a water jet. Such pressure may also be applied to opposite surfaces of the preform of fibers 108 to flatten the fibers. For example, preferred flattening or ovalization of fibers 108 occurs along the 90° to 270° axis when pressure is applied from directions of 0° and 180°.

In order to produce fibers 108 with a circularity of less than 90%, preferably less than 50%, additionally or alternatively, the orifice of the injection nozzle 122 may be provided with an oval (or more generally non-circular) nozzle cross-section Mouth 126.

Within the framework of the described mechanism for forming fibers 108 with a non-circular cross-section, one or more of the following options can be applied:

a) At high transport speeds of the fiber support unit 132, the conveyance of the fabric 102 in the MD direction leads to an implicit focusing of the average fiber alignment (obtainable from the sum of the transport speed and the deposition vector). An efficient orientation of the fiber alignment of the fabric 102 in the MD direction can be achieved especially when the transport speed is of the same order of magnitude as the deposition speed or even greater. Compared with the circular section, due to the fiber The cross-sectional stretching or flattening modification of the dimension 108 provides defined cross-sectional control of the deposited fiber 108 in the CD direction and may result in increased fiber orientation in the CD direction when the transport speed is zero. Thus, average or median values at transport speeds and CD deposition enhancements at which no preferential orientation of fibers 108 is obtained can be determined. In other words, under such conditions, even perfect uniformity can be obtained. It should be mentioned, however, that in some embodiments the deposition rate may be higher than the transfer rate, especially by orders of magnitude.

b) It is presently believed that a relatively small number of fibers 108 have been modified according to the principle described in a) such that more adjacent fibers 108 are also preferably oriented in the CD direction. This can be explained by the analogy of a forest in a storm. The first tree to break triggers a domino-like forest passage along the direction of the break.

c) By modifying the cross-sectional shape of the fibers 108, a friction-based clamping effect according to an exemplary embodiment of the present invention can be produced in the fabric 102. This results in self-inhibition like in a tapered tool container. This effect is already obtained with relatively small deviations in the cross-sectional shape of the fibers 108 compared to a circular cross-section. The transition from a circular cross-section to an oval cross-section enables the formation of such a self-inhibiting system with respect to another fiber 108 (also having a non-circular cross-section or having a circular cross-section).

Referring again to the embodiment depicted in FIG. 13 , one or more additional nozzle bars or nozzles 122 may be provided and may be arranged consecutively along the conveying direction of the fiber support unit 132 . Multiple spray nozzles 122 can be configured such that additional layers 200 of fibers 108 can be deposited on top of previously formed layers 202 (preferably at Before the coagulation or curing process of layer 202 and/or fibers 108 of layer 200 is fully completed), it may trigger interlayer consolidation. When the process parameters are adjusted appropriately, this may have a favorable effect on the properties of the multilayer fabric 102 : on the one hand, the first deposited layer 202 may be deposited on a conveyor belt, such as a conveyor belt, as the fiber support unit 132 . In such an embodiment, the fiber support unit 132 may be implemented as an ordered structure of release mechanisms and air suction openings (not shown). In the statistical distribution of the filaments of fiber 108 this may have the effect that a higher concentration of material may be found in areas where no air flow is present. Such (especially microscopic) material density variations can be considered mechanically perforated, the effect of which is a distortion of the uniformity of the nonwoven cellulosic fiber web 102 (in particular due to its tendency to suppress patterns). Apertures may be formed in the nonwoven cellulosic fiber web 102 at locations where air or liquid flow (eg, water) penetrates the nonwoven cellulosic fiber web 102 . With this fluid flow (where the fluid can be a gas or a liquid), the tensile strength of the nonwoven cellulosic fiber web 102 produced can be increased. Without wishing to be bound by a particular theory, it is presently believed that the second layer 200 may be considered a reinforcement layer for the first layer 202 that compensates for the reduced uniformity of the layer 202 . This increase in mechanical stability can be further improved by fiber diameter variation, particularly interfiber diameter variation and/or intrafiber longitudinal diameter variation of individual fibers 108 . When a deeper (particularly single point) pressure is applied, such as provided by air or water, the cross-sectional shape of the fibers 108 can be further deliberately distorted, which can advantageously result in a further increased mechanical stability.

On the other hand, an intended coalescence between the fibers 108 of the fabric 102 according to FIG. 13 can be triggered in order to further increase the mechanical stability of the fabric 102 . exist In this context, merging may be support contact point adhesion of the filaments contacting the fibers 108 , in particular merging prior to completion of the coagulation process of one or both fibers 108 . For example, incorporation can be facilitated by increasing contact pressure with fluid flow (eg, air or water flow). By taking this measure, the cohesion strength between the filaments or fibers 108 of one of the layers 200, 202 on the one hand and/or between the layers 200, 202 on the other hand can be increased.

According to the apparatus 100 of FIG. 13 , which is configured for the manufacture of a multilayer fabric 102 , a number of process parameters are implemented which can be used to design the shape and/or diameter, or diameter distribution, of the fibers 108 and fiber layers 200 , 202 . This is a result of the sequential arrangement of multiple injection nozzles 122, each of which can be operated with individually adjustable process parameters.

The high mechanical strength of the fabric 102 according to the exemplary embodiment of the present invention is also obtained by the following properties of the manufacturing process: First, the endless fibers 108 made of cellulosic material are used because the endless fibers 108 (compared to the short Fibers) have less disturbing transitions, allowing individual fibers 108 to have a higher load-carrying capacity. Second, such fibers 108 can be produced with a high degree of purity, since the corresponding fabric 102 has very little process-related heavy metal content. Third, the specific design of the carrier grid supporting the mesh or other carrier structure (the mesh support system) that can be implemented in the hydroentanglement manufacturing process allows the stiffness of the fabric 102 to be controlled. In particular, the stability of the fabric 102 can be significantly increased by (eg air- and/or water-induced) incorporation, allowing biomimetic structures with high load-carrying capacities to be obtained.

With proper process control, individual filaments can be provided with drill bits which can also be held in the fabric 102 which is easy to manufacture. Thus, twisting can be formed Fiber 108, which can have increased stretchability through a corresponding spring effect. At the same time, the elasticity of the fabric 102 comprising twisted fibers 108 may be limited. This can be used to further increase the stability of the fabric 102 . Especially when the fiber 108 is bent, there is an effect that the elasticity decreases as the bending radius increases. When proper airflow vorticity or turbulence is implemented, fabric 102 can be designed with twisted fibers 108 for further increased stability.

On the smooth, planar fiber receiving surface of the fiber support unit 132, the oval fibers 108 or filaments preferably rest on their broad sides. This has a strong influence on the properties of the fabric 102 produced, since this involves ordering effects. In particular, this allows fabric 102 to be produced with a relatively small thickness and a relatively high density.

Preferably, fabric 102 according to an exemplary embodiment of the present invention is composed of both round fibers 108 and non-round fibers 108 . Corresponding fabrics 102 may be produced by using mixing jet nozzles 122 with circular and non-circular orifices 126, and/or by permanent, cyclic, or iterative modification of process parameters.

In an exemplary embodiment of the invention, at least 2, in particular at least 3, more in particular at least 4, in particular up to 10 spray nozzles 122 arranged in succession for producing the fabric 102 may be implemented. Each spray nozzle 122 may include a plurality of orifices 126 . Each nozzle 122 may optionally have a circular and/or non-circular hole 126 .

By adjusting the coagulation and/or stretching conditions of the filaments of the lyocell spinning solution 104, the fabric 102 can also be produced in which the non-circular fiber portions in cross-section are perpendicular, or at least substantially perpendicular, to the surface of the fabric 102 And by orientation. This results in stable adhesion and curing of the fabric 102 .

This allows one or more of the following advantages to be obtained: high bulk fabric 102 produced at a relatively low grammage; identifiable layer structure with adjustable property profile; adjustable properties of fabric 102 on the upper and lower major surfaces; level Aligned oval fibers 108 allow high tensile strength at reduced longitudinal and transverse elongation; grammage can be adjusted over a wide range, for example, 8 g/m ² to 250 g/m ² .

In another exemplary embodiment of the present invention, the nonwoven cellulosic fiber fabric 102 is used in a biodegradable product. After biodegradation, no adhesive material or adhesive material remains. In particular, no significant amounts of heavy metals form components of such biodegradable products. By corresponding process design, unwanted particle wear from the fabric 102 can be prevented.

According to an exemplary embodiment of the invention, a defined deviation from a circular cross-section of an endless fiber 108 can be obtained in such a way that the cross-sectional shape varies along the longitudinal extension of such a fiber 108 . This can also be achieved by bending the fiber 108 beyond its elastic limit, so that a transition from an elastically bent state to a plastically bent state occurs. This effect can be enhanced by subsequent fixation of the bent fibers 108, for example by hydroentangling. When the non-woven cellulosic fiber fabric 102 is torn, the result is that at certain loop or shuttle eye structures, another endless fiber 108 is guided through the structure during tearing, the diameter no longer fits and in small shape changes self-inhibition has occurred. This increases the tear strength of the fabric 102 as a whole. This is particularly relevant with regard to the implementation of endless fibers 108 , in which the self-inhibiting effect promoted by deviations from the roundness of one fiber is stronger than with short fibers.

Very advantageously, the deviation of the cross-section of the fibers 108 from a circular cross-section can be combined with fiber diameter variations, in particular intra-fiber thickness variations and/or inter-fiber thickness variations. This combination results in a particularly significant increase in the mechanical stability of the fabric 102 .

In summary, one or more of the following adjustments may be made, inter alia, according to exemplary embodiments of the present invention:

- Low uniform fiber diameter for high smoothness of fabric 102

- A multilayer fabric 102 with low diameter fibers and relatively low speed allows high fabric caliper at low fabric density

- The isoabsorption curve of the functionalized layer allows to obtain a uniform moisture and fluid containment behavior, as well as a uniform behavior in terms of fluid release

- It is also possible to functionalize the monolayers 200, 202 differently to obtain a product with anisotropic properties (eg for wicking, oil containment, water containment, dedusting power, roughness).

Finally, it should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the scope of the patent application, any reference symbols in brackets shall not be interpreted as limiting the scope of the patent application. The words "comprising" and "comprises" etc. do not exclude the presence of elements or steps other than those listed in any claim or specification as a whole. Singular reference to an element does not exclude plural reference to such elements and vice versa. In a device claim enumerating several methods, several of these methods may be implemented by the same software or hardware item. The mere fact that certain measures are recited in mutually different claim claims does not indicate that a combination of these measures cannot be used to advantage.

In the following, examples for generating changes in the merge factor are described and shown in the table below. When using a constant spinning solution (i.e., a spinning solution with a constant consistency), especially a lyocell spinning solution, and a constant air flow (such as air throughput), the different incorporation factors in the cellulosic fiber fabric can be changed by changing Condensed spray stream to achieve. Thus, a relationship between the coherent spray stream and the merging factor can be observed, ie the trend of the merging behavior (the higher the coherent spray stream, the lower the merging factor). MD here means machine direction, and CD means cross direction.

Softness (described by known specific hand measurement techniques, measured with the so-called "fabric hand tester" on the basis of nonwoven standard WSP90.3, in particular the latest version valid at the priority date of this patent application) The consolidation trend described above will be followed. Intensity (described by Fmax) (for example according to EN 29073-3 and ISO 9073-3, especially the latest version in effect at the priority date of this patent application) will also follow the described consolidation trend. Accordingly, the softness and strength of the resulting nonwoven cellulosic fibrous web can be adjusted according to the degree of incorporation (as specified by the incorporation factor).

102: (non-woven cellulose fiber) fabric

104: Lyocell spinning solution

106: Condensed Fluid

108: fiber

128:Agglomeration unit

132: fiber support unit

270: Deformation unit

272: Forming Fluid

274: details

Claims (15)

A nonwoven cellulosic fiber fabric (102), wherein the fabric (102) comprises a network of substantially endless fibers (108), and wherein at least 1% of the fibers (108) have a circularity of no greater than 90% ( roundness), wherein the fibers (108) are anisotropically aligned within the fabric (102) to substantially define at least one preferential alignment direction (290), which is larger than other directions A portion of the fibers (108) are aligned along the at least one preferential alignment direction. The fabric (102) of claim 1, comprising at least one of the following features: wherein at least 3% of the fibers (108) have a non-circular cross-sectional shape with a circularity not greater than 90%; wherein At least 1% of the fibers (108) have a non-circular cross-sectional shape with a circularity not greater than 80%. The fabric (102) as claimed in claim 1 or 2, which includes at least one of the following features: wherein the smoothness of the fabric (102) (measured as a specific hand) is between 2mNm ² /g and 70mNm ² A range between /g; wherein the fibers (108) have a copper content of less than 5 ppm and/or have a nickel content of less than 2 ppm; wherein at least some of the fibers (108) are integrally merged at a merge location (204). The fabric (102) of claim 1 or 2, wherein different ones of the fibers (108) are at least partially located in different distinguishable layers (200, 202). Such as the fabric (102) of claim 4, wherein the fibers (108) of different layers (200, 202) have the same physical properties; or wherein the fibers (108) of different layers (200, 202) have different physical properties. The fabric (102) of claim 4, wherein fibers (108) of different layers (200, 202) are integrally combined at at least one combining location (204) between the layers (200, 202). The fabric (102) according to claim 1 or 2, wherein at least part of the fibers (108) are twisted. A method of manufacturing a nonwoven cellulosic fiber fabric (102) directly from a lyocell spinning solution (104), wherein the method comprises: passing the lyocell spinning solution (104) through at least one The injection nozzle (122) is extruded under the aid of the airflow (146) and enters the condensation in a fluid (106) environment, thereby forming substantially endless fibers (108); collecting the fibers (108) on a fiber support unit (132) to form the fabric (102); adjusting process parameters so that at least 1% of the fibers (108) The fibers (108) have a non-circular cross-sectional shape with a circularity not greater than 90%, and the fibers (108) are anisotropically aligned within the fabric (102) to substantially define at least one preferential alignment direction ( 290), a greater portion of the fibers (108) are aligned along the at least one preferential alignment direction compared to other directions. The method according to claim 8, wherein adjusting the process parameters includes applying force to the filaments of the lyocell spinning solution (104) before the coagulation is completed. The method of claim 9, wherein force is applied by directing a forming fluid towards the filaments of the lyocell spinning solution (104) before the coagulation is complete. The method according to any one of claims 8 to 10, wherein the method additionally comprises further collecting the fibers (108) and/or the fabric (102) after collecting on the fiber support unit (132) In situ processing, which is processing by at least one method of the group consisting of: hydroentanglement, needle punching, impregnation, steaming with pressurized steam, and calendering. A device (100) for producing a nonwoven cellulosic fiber fabric (102) directly from a lyocell spinning solution (104), wherein the device (100) comprises: at least one spray nozzle ( 122), which is configured for extruding the lyocell spinning solution (104) by means of an air flow (146); a coagulation unit (128), which is configured for spinning the extruded lyocell a solution (104) providing an environment of coagulating fluid (106) to form substantially endless fibers (108); a fiber support unit (132) configured to collect the fibers (108) to form the fabric (102); a control unit (140) configured to adjust process parameters such that at least 1% of the fibers (108) have a non-circular cross-sectional shape of no greater than 90% circularity, the fibers (108) in the fabric ( 102) is anisotropically aligned to substantially define at least one preferential alignment direction (290) along which a greater portion of the fibers (108) are aligned compared to other directions. The device (100) of claim 12, wherein at least part of the openings are oval. A method of using a non-woven cellulosic fiber fabric (102) according to any one of claims 1 to 7 for use in at least one of the group consisting of: wipes; dryers paper (dryer sheet); filters; sanitary products; medical application products; geotextiles; agricultural fabrics; clothing clothing; products for building technology; automotive products; furnishing; industrial products; products related to beauty, leisure, sports or travel; and products related to schools or offices. A product comprising the fabric (102) according to any one of items 1 to 7 of the patent application.

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