JP2020513070A - Non-woven cellulose fiber fabric with improved oil absorption capacity - Google Patents

Abstract

A non-woven cellulosic fiber fabric (102) made directly from a lyocell spinning solution (104) is described. The fabric (102) comprises a net of substantially endless fibers (108) and the fabric (102) exhibits an oil absorption capacity of at least 1900% by weight. Further, methods and apparatus for producing such fabric (102), products or composites containing such fabric, and various uses of such fabric (102) are described.

Description

  The present invention relates to non-woven cellulosic fiber fabrics, methods of making non-woven cellulosic fiber fabrics, apparatus for making non-woven cellulosic fiber fabrics, products or composites, and methods of using such fabrics.

  Lyocell technology directly dissolves cellulosic wood pulp or other cellulosic feedstock in a polar solvent (eg, n-methylmorpholine n-oxide, which may also be referred to as "amine oxide" or "AO") to produce various useful celluloses. It relates to producing a highly viscous shear thinning solution that can be converted into a system material. Commercially, this technology produces a family of cellulose staple fibers (commercially available under the trademark TENCEL® from Lenzing AG, Renzing, Austria) widely used in the textile industry. Used for. Other cellulosic products derived from Lyocell technology have also been used.

  Cellulose staple fibers have long been used as a component for conversion into nonwoven webs. However, direct application of Lyocell technology to the manufacture of nonwoven webs will provide properties and performance not possible with current cellulosic web products. It can be considered as the cellulosic version of the melt blown and spunbond technology widely used in the synthetic fiber industry, but important technical differences make it impossible to directly apply synthetic polymer technology to lyocell.

  Much work has been done to develop techniques for directly forming cellulosic webs from lyocell solutions (inter alia WO 98/26122, WO 99/47733, WO 98/07911). Pamphlet, U.S. Patent No. 6,197,230, International Publication No. 99/64649, International Publication No. 05/106085, European Patent No. 1358369, European Patent No. 2013390). Additional techniques are disclosed in WO07 / 124521A1 and WO07 / 124522A1.

  It is generally known that cellulosic materials are hydrophilic rather than lipophilic. For many applications, this is a highly valued property of cellulose-containing products. However, there are also many (potential) applications where the lipophilic (remarkably respective) oil absorption capacity is welcomed. This may increase the usefulness of the cellulosic material for products for known uses and may allow the cellulosic products to be applied to new uses not previously known.

  It may be necessary to improve the oil absorption capacity of cellulosic materials, especially non-woven cellulosic fiber fabrics.

  This need can be met by the subject matter of the independent claims. Advantageous embodiments of the invention are described by the dependent claims.

  According to a first aspect of the present invention there is provided a non-woven cellulosic fiber fabric which is produced directly from a lyocell spinning solution. The provided fabric includes a net of substantially endless fibers. This fabric exhibits an oil absorption capacity of at least 1900% by weight.

  The fabric described is based on the idea that a non-woven fibrous fabric or fibrous web can be taken to represent a structure comprising a plurality of cavities or voids formed between various adjacent fibers. In the original, non-immersed state of the fabric, these voids are filled with air. When the fabric absorbs oil, the voids are filled with oil or grease particles having a diameter (liquid, semi-fluid or pasty) that at least approximately matches the size of each void.

  In this exemplary physical image, the voids in the fabric can be viewed as representative of capillary cages capable of receiving oil therein. In this respect, it is pointed out that the capillary cage has the effect of capillary hysteresis when filling / removing fluid. This is due to the high pressure (when the contact angle is greater than 90 °) or the higher capillary suction force (when the contact angle is less than 90 °) compared to the steady state of the liquid-filled cage in order to put the liquid in the cage. Means that is required. Regarding the stability of oil absorption, it is important how stable the liquid oil particles stay in the voids. Specifically, the more stably the oil particles are contained in the voids, the greater the oil absorption capacity. The stability of "housing" depends on the state of the capillary, in particular (a) the size of the voids (respectively cavities) and (b) the contact angle, which depends on the surface properties of the materials involved, according to basic physical principles. To do. Moreover, it is clear that the degree of oil absorption capacity depends on the density of (appropriately sized) voids in the fabric.

  The parameter for adapting the size of the capillary cage is the so-called titer, which has been found to be indicative of the fiber diameter. If the titer in the fiber network (respectively fabric) changes, it is possible to provide a large number of capillary cages with different sizes for the absorption of oil particles of different diameters. Descriptively speaking, some adjustments in the fiber manufacturing process can lead to variations in the fiber diameter distribution throughout the fabric.

  It has already been mentioned at this point that the size as well as the size of the voids is a parameter of the affinity of the oil particles absorbed in the respective cavities. Additional details on this point are given below with respect to the pooling factor, which is also a very important parameter for oil absorption capacity.

  Engine oil was used to determine the oil absorption capacity (or liquid absorption capacity) of the fabric using Edana standard NWSP 010.4. Based on R0 (15), analyzes can be performed on the evaluation of liquid absorption of oils and fats. A fabric sample measuring 10 cm x 10 cm is used for the analysis. Determine the weight of the sample and tie the sample and ruler diagonally with a string. Then drop the sample into a container filled with oil. The time required to wet the fabric with oil is measured. Then the fabric is soaked in oil for 120 seconds. The fabric is then lifted from the oil by raising the ruler. Then, oil is dripped from the fabric for 30 seconds. Determining the weight of the oil-moistened fabric, subtracting the original weight of the fabric sample from the weight of the oil-moistened sample, and calculating the weight percent of the oil uptake so accepted relative to the dry weight of the fabric sample. Calculate the oil absorption capacity by.

  In connection with experimental tests on emulsions, ie mixtures of oily and aqueous components, the rate of suction of the aqueous component into the capillary voids (each wicking rate) results in the entrainment of the oily component with the aqueous component (each dragging). . Therefore, in applications using such emulsions, this dragging effect can also be taken into account. Specifically, in selecting an appropriate design of the fabric net structure, not only the capillary effect between the described fabric structure and oil (each oily component), but also the described fabric net structure The capillary effect between aqueous components should also be taken into account. Descriptively speaking, the aqueous component may push or pull the oleaginous component through the oleophobic barrier between the described fabric and the oil particles, resulting in improved oil absorption capacity. Due to this liquid handling property, this effect may be particularly advantageous for face masks, which may have a relatively low basis weight.

  Experimental tests have further revealed that the described fabrics exhibit a high degree of regularity (respectively ordering) within their spatial structure. This property facilitates easy adaptation of void size and / or shape by proper selection of process parameter values. Without being bound to any particular physical theory, the physical reason for the high degree of regularity or crystallinity of the fabrics described can be seen in the pronounced polarity of lyocell fibers based on the three hydroxyl groups of each monomer unit. . Since the glucose molecules are arranged in a chain containing hundreds of such molecules, the production of the described fabrics is substantially free from contamination by other similar glucose molecules as described above. A high degree of regularity can be obtained. The hydroxyl groups form a regular network of hydrogen bridges, which results in the following properties of the described fabric: (a) high degree of crystallinity, (b) extremely high hydrophilic behavior. , (C) high water retention capacity, (d) thermosetting capacity (no melting point), (e) coagulation capacity derived from aqueous N-methyl-morpholine (NMMO) solvent, and (f) inherent antistatic property dependent on water content. It may be possible to understand the properties.

  By controlling the process parameters of the lyocell spinning solution manufacturing procedure in an appropriate manner, the described oil absorption capacity can be achieved without additional (further) treatment of the fabric, especially without the application and / or use of additional chemicals. It is pointed out that it can already be achieved. This may provide the advantage that the final product containing the described fabric does not automatically contain residues of such chemicals.

In the context of the present application, the term "nonwoven cellulosic fiber fabric" (which may also be referred to as nonwoven cellulosic filament fabric) may especially mean a fabric or web composed of a plurality of substantially endless fibers. The term “substantially endless fibers” especially has the meaning of filament fibers which have a significantly longer length than conventional staple fibers. In another description, the term "substantially endless fibers" may especially mean a web formed from filament fibers having significantly less fiber ends per volume than conventional staple fibers. In particular, the endless fibers of the fabric according to exemplary embodiments of the present invention may have an amount of fiber ends per volume of less than 10,000 ends / cm ³ , especially less than 5,000 ends / cm ^3. . For example, using staple fibers instead of cotton, the length can be 38 mm (corresponding to the typical natural length of cotton fibers). In contrast, the substantially endless fibers of the nonwoven cellulosic fiber fabric may have a length of at least 200 mm, especially at least 1000 mm. However, one of ordinary skill in the art will recognize the fact that even endless cellulosic fibers may have breaks that may be formed by processes during and / or after fiber formation. As a result, non-woven cellulosic fiber fabrics made from substantially endless cellulosic fibers have significantly less fibers per mass as compared to nonwovens made from staple fibers of the same denier. Nonwoven cellulosic fiber fabrics can be produced by spinning a plurality of fibers, preferably by tapering and stretching the plurality of fibers toward a moving fiber support unit. Thereby, a three-dimensional net or web of cellulosic fibers is formed, which constitutes a non-woven cellulosic fiber fabric. The fabric may be made from cellulose as the primary or sole component.

  In the context of the present application, the term “Lyocell spinning solution” refers in particular to a solvent (eg N-methyl-morpholine, NMMO, “amine oxide”) in which cellulose (eg wood pulp or other cellulosic feedstock) is dissolved. A polar solution of a material such as "AO"). The Lyocell spinning solution is a solution, not a melt. Cellulose filaments can be produced from lyocell spinning solutions by reducing the concentration of solvent, for example by contacting the filaments with water. The process of initial production of cellulosic fibers from the lyocell spinning solution can be described as coagulation.

  In the context of the present application, the term "gas stream" refers in particular to cellulosic fibers or preforms thereof (ie, lyocell spinning solution) during and / or after the lyocell spinning solution exits the spinneret. Of gas, such as air, substantially parallel to the direction of travel of the.

  In the context of the present application, the term "coagulation fluid" refers in particular to a non-solvent fluid (ie gas and / or liquid) which has the ability to dilute the lyocell spinning solution and replace the solvent to the extent that cellulose fibers are formed from lyocell filaments. , Optionally including solid particles). For example, such a coagulating fluid can be a water mist.

  In the context of the present application, the term "process parameter" is used in particular for producing non-woven cellulosic fiber fabrics, which can influence the properties of the fibers and / or fabrics, in particular the fiber diameter and / or the fiber diameter distribution. It can mean any physical and / or chemical and / or device parameter of the substance and / or device component. Such process parameters may be automatically adjusted by the control unit and / or manually adjustable by the user, thereby adjusting or adjusting the fiber properties of the non-woven cellulosic fiber fabric. . The physical parameters that can affect the properties of the fibers, especially their diameter or diameter distribution, include the temperature, pressure and the various media involved in the process (eg, lyocell spinning solution, coagulating fluid, gas stream, etc.). It can be / or density. The chemical parameter can be the concentration, amount, pH value of the medium involved (eg, lyocell spinning solution, coagulation fluid, etc.). Device parameters may include orifice size and / or distance between orifices, distance between orifices and fiber support unit, transport rate of fiber support unit, provision of one or more optional in situ aftertreatment units, gas flow, etc. Can be.

  The term “fiber” may especially mean an elongated piece of material comprising cellulose, for example formed in a substantially circular or irregular cross-section, optionally twisted with other fibers. The fibers may have an aspect ratio of greater than 10, especially greater than 100, more specifically greater than 1000. Aspect ratio is the ratio of fiber length to fiber diameter. The fibers are either merging (so that an integrated multi-fiber structure is formed) or friction (the fibers remain separated, but when the fibers that are in physical contact with each other are moved to each other). (As weakly mechanically coupled by the acting frictional forces) to form a net. The fibers may have a substantially cylindrical shape, but may be straight, bent, twisted or curved. The fibers may be composed of a single homogeneous material (ie cellulose). However, the fibers may also include one or more additives. Liquid materials such as water or oil may accumulate between the fibers.

  According to one embodiment of the invention, the fabric has a unit area mass of less than 150 grams per square meter, in particular less than 100 grams per square meter, more particularly less than 50 grams per square meter and even more particularly less than 20 grams per square meter. Have.

  By improving the oil absorption capacity of fabrics having a low unit area mass, these fabrics can have the advantage that they can be used in a variety of applications that require thin wipes, for example.

  It is mentioned that the term "unit area mass" is often also referred to as basis weight.

  According to a further embodiment of the invention, the mesh exhibits a fiber merging factor in the range 0.1% to 100%, in particular in the range 0.5% to 10%.

  To determine the fabric merging factor (which may also be referred to as the area merging factor), the following determination process may be performed. That is, a square sample of fabric is optically analyzed. A circle is drawn around each merging position (in particular, the merging point, the merging pad and / or the merging line) of the fibers that intersects at least one of the diagonals of the square sample, the circle having a diameter that should fit completely inside the square sample. The size of the circle is determined so that the circle encompasses the merged area between the merged fibers. Calculate the arithmetic mean of the determined circle diameter values. The pooling factor is calculated as the ratio of the average diameter value to the diagonal length of the square sample and can be expressed as a percentage.

  A merging factor of zero or 0% corresponds to a fabric without merging points, i.e. completely separated fibers that interact with each other only by interfiber hydrogen bonding or friction. A merge factor of 1 or 100% represents a fabric composed of fully integrated fibers forming a continuous structure such as a film. By adjusting the merging factor, it is also possible to adjust the physical properties (especially mechanical stability) of the corresponding fabric.

  By controlling the merging factor, some properties of the resulting fabric can be adjusted. In connection with the oil absorption capacity, it is possible in particular to control the cavities between the fibers (respectively filaments). In combination with the variation in fiber diameter, a tailor-made fabric structure can be realized, especially for high oil or grease uptake.

  In one embodiment, the merging positions (of the merging points) are distributed asymmetrically and / or anisotropically throughout the fabric. This means that the merging factor, the density of the merging points, or any other parameter indicative of the degree of local occurrence of merging between the fibers may be different for different volume portions of the fabric. For example, a fabric composed of two layers may be composed of one layer having a larger merging factor than another layer having a relatively smaller merging factor. The merging factor of each layer can be adjusted by adjusting the formation of this layer or by controlling the process independently or in a different way from adjusting the formation of the other layer or by the process control.

  According to a further embodiment of the invention, at least some individual fibers are twisted together and / or at least one other fiber structure is twisted with another fiber structure. This may (further) improve the mechanical stability of the described fabrics.

  In the context of this document, a "fiber structure" can be any fiber arrangement comprising at least two fibers. Thereby, the fibers can be individual fibers that at least partially contact one another. Alternatively, or in combination, the fiber structure may be a structure that includes at least two fibers that are integrally connected at at least one merging location.

  According to a further embodiment of the invention, the fabric exhibits an oil absorption capacity of at least 2100% by weight, in particular at least 2300% by weight, especially at least 2500% by weight.

  Since cellulosic materials inherently exhibit very little oil absorption capacity, polyethylene terephthalate (PET), which is a highly lipophilic material by its nature, has been used with appropriate process parameter values to produce the described fabrics. It is mentioned that an oil absorption capacity comparable to that of can be achieved. Moreover, the oil absorption capacity described is even greater than that of some tested polypropylene (PP) fabrics.

  According to a further embodiment of the invention, each different of the fibers is at least partly located in a different distinguishable layer. In this context, "distinguishable" may mean, in particular, that the fabric exhibits visible separation or interfacial areas between layers, at least in images captured, for example, by electron microscopy.

  Descriptively speaking, the fabrics described exhibit a multi-layer structure in which at least two mesh layers are formed on top of each other. By controlling the process parameters such that the various different mesh layers have qualitatively and / or quantitatively different functionality, the physical properties of the entire fabric in many ways (towards) in many specific applications. And / or the chemical properties can be adjusted. This can greatly extend the field of technical applicability of the fabrics described.

  At least three layers of fabric may be used, for example for wipes, preferably the inner layer may be immersed in a liquid, in particular an oily liquid, which in use is released in a controlled manner through at least one of the outer layers. . Thereby, the different functional properties of each layer can be adjusted, for example by selecting an appropriate range of fiber diameters.

  It is noted that there is no major limit on the maximum number of network layers that can be stacked. Depending on the particular application, multilayer fabrics may be made up of 2 to 4 layers or even more, for example 5 to 20 stacked mesh layers.

  Compared to the known multilayer fabrics, the position of the layer merging or the point of layer merging essentially eliminates the use of an additional adhesive material which involves some penetration into the interior of at least one of the two mesh layers. Mutual attachment between the two layers is possible. Furthermore, mutual adhesion does not depend on the penetration of one type of fiber into the layers assigned to the other type of fiber. As a result, upon tearing the two layers, which may be desirable in some applications, fiber failure is limited to a minimal amount and the layer's original attachment surface is substantially free of fringes. Moreover, the desired tearing causes only minimal linting.

  Due to the fact that no additional adhesive material is required for the mutual attachment of the two layers, the fabric can be realized in an environmentally compatible manner. In particular, the multilayer fabrics described can be used in products that are fully biodegradable. In addition, the absence of additional adhesive material such as a binder between adjacent layers can provide the advantage that liquid can spread smoothly to the interface of each layer.

According to a further embodiment of the invention, the fabric comprises at least one of the following features.
(A) Fibers of different layers are integrally connected at at least one inter-layer merging position between layers.
(B) Each different fiber located at least partially in a different layer differs with respect to the fiber diameter, in particular with respect to the average fiber diameter.
(C) The fibers of the different layers have the same fiber diameter, especially substantially the same average fiber diameter.
(D) Different layers of fiber network provide different functionalities, which differ among other things: different wicking properties, different anisotropic behavior, different liquid absorption capacity, different cleanability, different optical properties, different roughness, At least one of the group consisting of different smoothness and different mechanical properties.

  The inter-layer merging position described in item (a) above can be created by aligning two (or more) jets in series with orifices through which the lyocell spinning solution is extruded for coagulation and fiber formation. When such an arrangement is combined with a moving fiber support unit (such as a conveyor belt having a fiber receiving surface), a first layer of fibers is formed on the fiber support unit by the first jet and the moving fiber support unit is formed. When the unit reaches the position of the second jet, the second jet forms a second layer of fibers on the first layer. The process parameters of this method may be adjusted so that the merge point is formed between the first layer and the second layer.

  In the context of the present application, the term “merging” may especially mean the interconnection of different fibers at each point of merging, whereby this formerly two (previously associated with different layers) An integrally connected fiber structure is formed which is composed of fibers that have been separated into. The interconnected fibers can strongly adhere to each other at the point of merging. In particular, the fibers of the forming second layer, which have not yet been fully hardened or solidified by solidification, are, for example, still in the liquid Lyocell solution phase and still have the outer skin or surface area still in the fully hardened solid state. Can have. When such pre-fibrous structures come into contact with each other and then fully cure into a solid fiber state, two interlocking fibers may form at the interface between the different layers. The greater the number of merging points, the more stable the interconnection between the layers of the fabric. Therefore, by controlling the merging, the stiffness of the connections between the layers of the fabric can be controlled. The merging can be controlled, for example, by adjusting the degree of hardening or coagulation before the pre-fibrous structure of each layer reaches the fiber or the fiber support plate on the lower layer of the pre-fibrous structure. By merging fibers of different layers at the interface between them, unwanted separation of layers can be prevented. If there is no merging point between the layers, it may be possible to peel one layer of fibers from the other.

  As explained in item (b) above, if different layers of the fabric are formed from fibers having different (average) diameters, the mechanical properties of the different layers may be adjusted differently separately. For example, one of the layers may be provided with rigidity properties by using fibers having a relatively large diameter, while the other layer is provided (eg, by using fibers having a relatively small diameter). It may have smooth or elastic properties. For example, it has a rough surface for cleaning by mechanically removing dirt, and has a smooth surface for wiping, that is, configured to absorb water etc. from the surface to be cleaned. Wipes can be manufactured.

  As described in item (c) above, if the fibers of different layers have the same (average) diameter, adjacent layers may have similar or identical physical properties. They can be strongly or weakly interconnected at the points of merge between them. The number of such merging points per interface region may define the bond strength between adjacent layers. The low bond strength allows the layers to be easily separated by the user. With high bond strength, the layers can remain permanently attached to each other.

  According to a further embodiment of the invention, the different layers of fiber network have different merging factors. This can contribute to the improved mechanical stability of the described fabrics.

  Specifically, by controlling the merging factor along the height or z-direction perpendicular to the plane of the layers, the endless fibers contact the fiber-supporting unit that collects the fibers during the process of making the described fabric. When this is done, a constant pretension can be achieved. Thereby, the height-dependent distribution of the different merging factors leads to high mechanical stability, and when the oil particles are embedded in the fabric, the pressure of the adhesive forces causes the capillary cavities formed in the described fabric. Or it may be possible to build a "force absorbing spring system" that effectively prevents the voids from collapsing.

  According to a further embodiment of the invention, the fibers have a copper content of less than 5 ppm and / or a nickel content of less than 2 ppm. All ppm values mentioned in this application relate to mass (rather than volume). Alternatively, heavy metal contamination of the fiber or fabric may be 10 ppm or less for each individual heavy metal element. Copper (such as N-methyl-morpholine, NMMO, etc.), copper or nickel (which may cause the user's allergic reaction) to use the lyocell spinning solution as the basis for forming a fabric based on endless fibers It is possible to suppress the contamination of the cloth by the heavy metal of 1.

  According to a further aspect of the invention, there is provided a method of directly producing a non-woven cellulosic fiber fabric, in particular the fabric described above, from a Lyocell spinning solution. A method is provided for: (a) extruding a lyocell spinning solution supported by a gas stream into a coagulating fluid atmosphere via a jet having an orifice, thereby forming a substantially endless fiber; (b) Collecting the fibers on a fiber support unit to form a fabric thereby, (c) adjusting the process parameters of the manufacturing process such that the fabric exhibits an oil absorption capacity of at least 1900% by weight.

  The method provided is based on the idea that multiple cavities or voids can be formed between various adjacent fibers. By choosing the appropriate process parameters, the size and / or shape of these voids can be set appropriately. In the original, non-immersed state of the fabric, these voids are filled with air. When the fabric absorbs oil, the voids are filled with oil or grease particles having a diameter (liquid, semi-fluid or pasty) that at least approximately matches the size of each void.

  In the context of this document, a "jet with orifices" (which may be referred to as an "orifice arrangement") may be any structure with a linearly arranged arrangement of orifices.

According to an embodiment of the invention adjusting the process parameter comprises at least one of the following features.
(A) after the lyocell spinning solution exits the orifice and before the lyocell spinning solution reaches the fiber support unit, by causing an interaction between the lyocell spinning solutions extruded through each of the different orifices, Form at least a part.
(B) forming at least a portion of the merged position by causing coagulation of at least a portion of the fibers upon placement on the fiber support unit after the lyocell spinning solution reaches the fiber support unit.
(C) arranging a plurality of jets having orifices in series along a movable fiber support unit, depositing a first layer of fibers on the fiber support unit, and at least one of the fibers at an interface between the layers. Depositing a second layer of fibers on the first layer before the solidification of the part is complete.

  As described in item (a) above, forming at least a portion of the merging position after the lyocell spinning solution exits the orifice and before the lyocell spinning solution reaches the fiber support unit is, for example, It can be achieved by causing an interaction between the strands of the lyocell spinning solution extruded through each of the different orifices, while accelerating. For example, the gas flow may be adjusted with respect to velocity and direction such that different strands or filaments of the spinning solution (not yet fully coagulated) interact laterally with each other before reaching the fiber support unit. . The gas flow can also be operated close to, or turbulent to facilitate interaction between the various fiber preforms. Thus, individual preforms of fibers may be brought into contact with each other prior to solidification, thereby forming a merged location.

  As explained in item (b) above, forming the at least part of the merged position after the lyocell spinning solution reaches the fiber support unit can be achieved by intentionally delaying the process of coagulation. This delay may be adjusted by corresponding operation of the coagulation unit, in particular by correspondingly adjusting the characteristics and position of the supply of coagulation fluid. More specifically, the process of coagulation may be delayed until the spinning solution reaches the fiber support plate. In one such embodiment, the preform of the fiber prior to solidification still reaches the fiber support unit, thereby contacting another preform of the fiber also prior to solidification. Thereby, the spinning solutions of the different strands or preforms can be forced to flow into contact with each other and only after that coagulation can be caused or completed. Therefore, coagulation following initial contact between different preforms of fibers that are still in the non-coagulated state is an efficient measure of forming a merged location.

  Arranging a plurality of jets having orifices in series along the movable fiber support unit, and the following steps described in item (c) above can also contribute to achieving an appropriate oil absorption capacity. Thereby, for each layer formed, the process parameters for operating the corresponding jets with orifices may be adjusted to obtain layer-specific solidification behavior. The layer-specific solidification behavior of different layers may be tailored such that (intra-layer) merging positions are formed in each layer and (inter-layer) merging positions are formed between adjacent layers. More specifically, the process control is adjusted to form a merged position between two adjacent layers by promoting coagulation of both layers only after initial contact between the spinning solutions associated with the different layers. Good.

  According to a further embodiment of the invention, the method further comprises further treating the fibers and / or fabric in situ after collection on the fiber support unit. This additional treatment comprises at least one of the group consisting of hydroentanglement, needle punching, impregnation, steam treatment with pressurized steam, and calendering, among others.

  Such an in-situ process is a process performed before the manufactured (especially substantially endless) fabric is stored (eg, wound by a winder) for shipment to a product manufacturing destination. obtain. For example, such additional treatment or post-treatment may include hydroentanglement. Hydroentanglement is sometimes referred to as the wet or dry fibrous web bonding process, and the resulting bonded fabric is a non-woven fabric. Hydroentanglement may use a fine, high-pressure water jet that penetrates the web, impinges on the fiber support units (especially conveyor belts), and bounces back to entangle the fibers. The corresponding compression of the fabric allows it to be made more compact and mechanically more stable. In addition to or instead of hydroentanglement, steaming of the fibers with pressurized steam may be performed. Additionally or alternatively, such additional treatment or post-treatment may include a needling treatment of the manufactured fabric. A needle punch system may be used to bond the fibers of the fabric or web. Needle punched fabrics can be manufactured by pushing barbed needles into the fibrous web and pushing some of the fibers that remain when the needle is withdrawn into the web. When sufficient fibers are suitably replaced, the reinforcing effect of these fiber plugs allows the web to be converted into a fabric. Yet another additional treatment or post-treatment of the web or fabric is an impregnation treatment. Impregnation of the endless fiber network may include applying one or more chemicals (such as softeners, hydrophobizing agents and antistatic agents) to the fabric. Yet another additional processing of the fabric is calendaring. Calendering may be referred to as a finishing process for treating the fabric, where calendering may use a polisher to smooth, coat, and / or compress the fabric.

  According to a further aspect of the invention, there is provided an apparatus for producing a non-woven cellulosic fiber fabric directly from a Lyocell spinning solution, in particular for producing the fabric described above. An apparatus provided is (a) a jet having an orifice configured to extrude a lyocell spinning solution supported by a gas stream, and (b) providing a coagulating fluid atmosphere to the extruded lyocell spinning solution, At least a coagulation unit configured to form substantially endless fibers according to, (c) a fiber support unit configured to collect the fibers and thereby form a fabric, and (d) the fabric And a control unit configured to adjust the process parameters to exhibit an oil absorption capacity of 1900 wt%.

  The device described is based on the idea that the control unit is also able to carry out in a reliable manner the above-mentioned method for producing a non-woven cellulosic fiber fabric as described above.

  According to a further aspect of the present invention there is provided a method of using the non-woven cellulosic fiber fabric described above. Fabrics include dryer sheets, facial masks, hygiene products, wipes, filters, medical products, geotextiles, agrotextiles, clothing, building technology products, automotive products, furniture. , Industrial products, leisure, beauty, sports or travel related products, and school or office related products.

  When the described fabrics are used in dryer sheets, oil absorption capacity may be used to deposit active ingredients released during the drying procedure performed in the washer dryer. The process of release can be assisted, for example, by heat shrinkage and corresponding squeezing of the cavities containing oil particles.

  When the described fabrics are used in facial masks, special advantages can be obtained from their great capacity for optimal oils and / or emulsions on human skin.

  When using the described fabrics for cleaning wipes, for example household wipes, benefiting from a high uptake of oil in removing oily residues in the kitchen without the use of chemicals or surfactants You can

  The high oil uptake of the fabrics described may also be beneficial, in particular for removing make-up without the need for personal care wipes, for example surfactants containing lotions.

  According to a further aspect of the invention there is provided a product or composite comprising the non-woven cellulosic fiber fabric described above.

  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 provide an exemplary embodiment of the present invention. It can form a complex. Exemplary materials that can be combined with fabrics to form such composites include, but are not limited to, the following materials or combinations thereof: fluff pulp, fiber suspension, wet laid ( wetlaid) nonwoven fabric, airlaid nonwoven fabric, spunbond web, meltblown web, carded spunlace web or needle punched web, or other sheet-like structures made from various materials. In one embodiment, the connections between the different materials are made by one or a combination of, but not limited to, the following processes: merging, hydroentanglement, needle punching, hydrogen bonding, thermal bonding, binder bonding, laminating. And / or calendering.

  Specific applications of webs, 100% cellulosic fibrous webs, or webs comprising, for example, two or more fibers, or antimicrobial materials, ion exchange materials, activated carbons, nanoparticles, lotions, drugs or flame retardants, or composite fibers. A chemically modified fiber or fibers incorporating materials such as can be as follows.

  Nonwoven cellulosic fiber fabrics according to exemplary embodiments of the present invention are for baby wipes, kitchen wipes, wet wipes, cosmetic wipes, hygiene wipes, medical wipes, cleaning wipes, abrasives (cars, furniture). It may be used to manufacture wipes such as wipes, dust wipes, industrial wipes, dusters and mop wipes.

  Nonwoven cellulosic fiber fabrics according to exemplary embodiments of the present invention can also be used in the manufacture of filters. For example, such filters include air filters, HVAC, air conditioning filters, exhaust gas filters, liquid filters, coffee filters, tea bags, coffee bags, food filters, water filters, blood filters, tobacco filters, cabin filters, oil filters, cartridges. Filters, vacuum filters, vacuum cleaner bags, dust filters, hydraulic filters, kitchen filters, fan filters, moisture exchange filters, pollen filters, HEVAC / HEPA / ULPA filters, beer filters, milk filters, coolant filters, and fruit filters. It may be a juice filter.

  In yet another embodiment, non-woven cellulosic fiber fabrics may be used to make absorbent hygiene products. Examples include acquisition layers, coverstocks, distribution layers, absorbent covers, sanitary napkins, topsheets, backsheets, leg cuffs, flushable products, pads, nursing pads, disposable underwear, training pants, face masks, Mention may be made of cosmetic facial masks, cosmetic removal pads, washcloths, diapers, and washer / dryer sheets that release active ingredients such as fabric softeners.

  In yet another embodiment, the non-woven cellulosic fiber fabric may be used to make a medical use product. For example, such medical use products include disposable caps, gowns, masks and shoe covers, wound care products, sterile packaging products, cover stock products, bandage materials, one way clothing, dialysis products, nasal strips ( nasal strips, denture adhesives, disposable undergarments, drapes, wraps and packs, sponges, bandages and wipes, bed linens, transdermal drug delivery, shrouds, underpads, procedure packs, heat packs, ostomy. It can be a bag liner, a fastening tape as well as an incubator mattress.

  In yet another embodiment, non-woven cellulosic fiber fabrics may be used to make geotextiles. This includes crop protection covers, capillary mats, water purification products, irrigation control products, asphalt overlays, soil stabilization products, drainage products, sedimentation and erosion control products, pond linings, impregnation based products, drainage canals. Linings, ground stabilization products, hole linings, seed blankets, weed control fabrics, greenhouse coverings, root bags and biodegradable flowerpot manufacturing. It is also possible to use non-woven cellulosic fiber fabrics for plant foils (eg to provide plants with light protection and / or mechanical protection, and / or to provide plants or soil with fertilizers or seeds). ).

  In another embodiment, non-woven cellulosic fiber fabrics may be used to make garments. For example, interlining, clothing insulation and protection, handbag components, shoe components, belt liners, industrial hats / foodwear, disposable workwear, clothing and shoe bags, and insulation materials. It may be manufactured based on a fabric.

  In yet another embodiment, non-woven cellulosic fiber fabrics may be used to make products used in building technology. For example, roofing and tile underlayment, slate for underlayment, insulation and sound insulation, house wrap, surface finish for gypsum board, pipe wrap, concrete forming layer, foundation and ground stabilization. Products, vertical drainage, shingles, roofing felts, noise abatement materials, stiffeners, sealing materials, and damping materials (mechanical), even if manufactured using such fabrics Good.

  In yet another embodiment, the non-woven cellulosic fiber fabric may be used to make automotive products. Examples are cabin filters, trunk linings, parcel shelves, heat shields, shelf trims, molded bonnet linings, trunk floor covers, oil filters, headliners, rear parcel shelves, decorative fabrics, air. Bags, sound deadening pads, insulation, car covers, underpadding, car mats, tapes, lined and tufted carpets, seat covers, door trims, needle carpets, and automotive carpet backings.

  Yet another area of application for fabrics made in accordance with exemplary embodiments of the present invention is furniture, construction, arm and back insulation, cushion thickeners, dust covers, liners, seam reinforcements, edge trim materials. , Bedding construction, quilt lining, spring wrap, mattress pad components, mattress covers, window curtains, wall coverings, carpet lining, lampshades, mattress components, spring insulation, sealing, pillow thickening Furniture such as wood and thickening mattress.

  In yet another embodiment, non-woven cellulosic fiber fabrics may be used to make industrial products. This includes electronics, floppy disk linings, cable insulators, abrasives, insulating tapes, conveyor belts, noise absorbing layers, air conditioning products, battery separators, acid systems, non-slip mats, stain removers, Food wraps, adhesive tapes, sausage casings, cheese casings, artificial leather, oil recovery booms and socks, and papermaking felts may be included.

  The non-woven cellulosic fiber fabric according to exemplary embodiments of the present invention is also suitable for manufacturing products related to leisure and travel. Examples of such applications include sleeping bags, tents, luggage, handbags, shopping bags, airplane headrests, CD protection products, pillowcases and sandwich packaging.

  Yet another area of application of the exemplary embodiments of this invention relates to school and office products. As examples, mention should be made of book covers, mailing envelopes, maps, bulletin boards and pennants, towels, and flags.

  It should be noted that the embodiments of the present invention have been described with reference to different subject matters. In particular, some embodiments have been described with reference to apparatus type claims whereas other embodiments have been described with reference to method type claims. However, one of ordinary skill in the art will appreciate that, unless otherwise noted, any combination of features belonging to one type of subject matter, as well as any combination of features relating to different subject matter, particularly apparatus-type claims, It will be inferred from the above and following description that any combination between features and method type claims is also considered to be disclosed herein.

  The aspects defined above and further aspects of the invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment. The invention will be explained in more detail below with reference to examples of embodiments, but the invention is not limited thereto.

1 illustrates an apparatus for manufacturing a non-woven cellulosic fiber fabric formed directly from a Lyocell spinning solution coagulated by a coagulating fluid, according to an exemplary embodiment of the present invention. 3 shows experimentally captured images of non-woven cellulosic fiber fabrics according to an exemplary embodiment of the present invention where individual fiber merging was achieved by specific process controls. 3 shows experimentally captured images of non-woven cellulosic fiber fabrics according to an exemplary embodiment of the present invention where individual fiber merging was achieved by specific process controls. 3 shows experimentally captured images of non-woven cellulosic fiber fabrics according to an exemplary embodiment of the present invention where individual fiber merging was achieved by specific process controls. Figure 4 shows an experimentally captured image of a non-woven cellulosic fiber fabric according to an exemplary embodiment of the present invention in which fiber swelling has been achieved, which figure shows the fiber fabric in a dry, unswollen state. Figure 4 shows an experimentally captured image of a non-woven cellulosic fiber fabric according to an exemplary embodiment of the present invention in which fiber swelling has been achieved, which figure shows the fiber fabric in a wet swollen state. Experimentally captured image of a non-woven cellulosic fiber fabric according to an exemplary embodiment of the present invention where formation of two superposed layers of fibers was achieved by a particular process implementing two in-line bars of nozzles. Indicates. 3 shows experimentally captured images of a non-woven cellulosic fiber fabric according to an exemplary embodiment of the present invention, where the process control adjusts the merging factor to approximately 100%. 5 shows an experimentally captured image of a non-woven cellulosic fiber fabric according to another exemplary embodiment of the present invention where the process control has adjusted the merge factor to approximately 0%. 7 shows an experimentally captured image of a non-woven cellulosic fiber fabric showing oil absorption capacity with a small merging factor. 7 shows an experimentally captured image of a non-woven cellulosic fiber fabric showing oil absorption capacity with a large merging factor. 1 illustrates a portion of an apparatus for making a nonwoven cellulosic fiber fabric composed of two laminates of an endless cellulosic fiber web, according to an exemplary embodiment of the invention. 1 illustrates a non-woven cellulosic fiber fabric including three mesh layers.

  The figures in the drawings are schematic. It should be noted that in different figures, similar or identical elements or features are provided with the same reference signs. In order to avoid unnecessary repetition, elements or features already described with respect to the previously described embodiments will not be described again in subsequent positions of the description.

  Furthermore, spatially relative terms such as “front” and “rear”, “top” and “bottom”, “left” and “right” refer to one element and another element as shown in the figure. Used to describe the relationship with. Therefore, spatially relative terms may apply to orientations in use that differ from the orientations shown in the figures. Apparently, all such spatially relative terms refer to the orientation shown in the figures for ease of explanation only, and the device according to one embodiment of the invention is, when in use, the one shown in the figures. It is not necessarily limited as it can take different orientations from.

  FIG. 1 shows an apparatus 100 according to an exemplary embodiment of the invention for producing a non-woven cellulosic fiber fabric 102 formed directly from a Lyocell spinning solution 104. The lyocell spinning solution 104 is at least partially coagulated by the coagulating fluid 106 and converted into partially formed cellulose fibers 108. The device 100 may perform a lyocell solution spraying process according to an exemplary embodiment of the present invention. In the context of the present application, the term “Lyocell solution spraying process” can, in particular, result in discrete lengths of essentially endless filaments or fibers 108, or a mixture of discrete lengths of endless filaments and fibers. It may include a process. Nozzles, each having an orifice 126, are provided, with a gas stream or gas stream 146 for producing a nonwoven cellulosic fiber fabric 102 according to an exemplary embodiment of the present invention, as further described below. The cellulose solution or Lyocell spinning solution 104 is jetted.

  As can be seen from FIG. 1, wood pulp 110, other cellulosic raw materials, etc. may be supplied to the storage tank 114 via the metering unit 113. Water from the water container 112 is also supplied to the storage tank 114 via the measuring unit 113. Therefore, the metering unit 113 may define the relative amount of water supplied to the storage tank 114 and the wood pulp 110 under the control of the control unit 140, which will be described in more detail below. The solvent (N-methylmorpholine, NMMO, etc.) contained in the solvent container 116 may be concentrated in a concentrating unit 118, and then in a mixing unit 119, a definable relative amount of water and wood pulp 110. Or other cellulosic materials. Also, the mixing unit 119 may be controlled by the control unit 140. This causes the water wood pulp 110 medium to be dissolved in the lysing unit 120 in an adjustable relative amount of concentrated solvent, thereby providing the lyocell spinning solution 104. Aqueous lyocell spinning solution 104 comprises a honey viscous medium composed of cellulose (e.g. 5% to 15% by weight) containing wood pulp 110 and solvent (e.g. 85% to 95% by weight). Can be.

  The lyocell spinning solution 104 is sent to a fiber forming unit 124 (which may be embodied as or equipped with multiple spinning beams or jets 122). For example, the number of orifices 126 of the jet 122 may be greater than 50 and especially greater than 100. In one embodiment, the orifices 126 of the jet 122 (which may comprise multiple spinnerets of the jet 122) may all have the same size and / or shape. Alternatively, the different orifices 126 of one jet 122 and / or the orifices 126 of different jets 122 (which may be arranged in series to form a multi-layered fabric) may have different sizes and / or shapes. Orifices 126 may be arranged as a one-dimensional array of orifices 126.

  As lyocell spinning solution 104 passes through orifice 126 of jet 122, it is split into a plurality of parallel strands of lyocell spinning solution 104. A vertically oriented gas stream, ie a gas stream oriented substantially parallel to the spinning direction, transforms the Lyocell spinning solution 104 into increasingly longer and thinner strands, which are under the control of the control unit 140. It can be adjusted by changing the process conditions. The gas flow may accelerate the lyocell spinning solution 104 along at least a portion of the way from the orifice 126 to the fiber support unit 132.

  While the lyocell spinning solution 104 travels further down through the jet 122, the long thin strands of lyocell spinning solution 104 interact with the non-solvent coagulating fluid 106. The solidification fluid 106 is advantageously embodied as a vapor mist, such as an aqueous mist. The process-related properties of the coagulation fluid 106 are controlled by one or more coagulation units 128 to provide the coagulation fluid 106 with adjustable properties. The coagulation unit 128 is then controlled by the control unit 140. Preferably, a respective coagulation unit 128 is provided between individual nozzles or orifices 126 to individually tailor the properties of the respective layers of fabric 102 during manufacture. Preferably, each jet 122 may have two assigned coagulation units 128, one from each side. Thus, each jet 122 may be provided with an individual portion of the Lyocell spinning solution 104 that may be tailored to have different controllable properties of different layers of the manufactured fabric 102.

  Interaction with the coagulation fluid 106 (such as water) reduces the solvent concentration of the lyocell spinning solution 104, which results in the cellulose in the lyocell spinning solution 104, eg, wood pulp 110 (or other raw material) (still remaining solvent). And can contain water) and are at least partially coagulated as long fine cellulosic fibers 108.

  During or after the initial formation of the individual cellulosic fibers 108 from the extruded Lyocell spinning solution 104, the cellulosic fibers 108 are deposited on a fiber support unit 132, here embodied as a conveyor belt having a planar fiber receiving surface. Cellulose fibers 108 form a non-woven cellulosic fiber fabric 102 (shown only schematically in FIG. 1). Nonwoven cellulosic fiber fabric 102 is composed of continuous, substantially endless filaments or fibers 108.

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

  The non-woven cellulosic fiber fabric 102 may be washed while being transported along the fiber support unit 132 by a washing unit 180 that supplies a washing liquid to remove residual solvent and may then be dried. The nonwoven cellulosic fiber fabric 102 can be further processed by an optional but advantageous additional processing unit 134. For example, such additional processing can include hydroentanglement, needle punching, impregnation, steam treatment with pressurized steam, calendering, and the like.

  The fiber support unit 132 may also transport the non-woven cellulosic fiber fabric 102 to the winder 136, on which the non-woven cellulosic fiber fabric 102 may be collected as a substantially endless sheet. The non-woven cellulosic fiber fabric 102 may then be shipped as a roll product to an entity that manufactures products such as wipes or fabrics based on the non-woven cellulosic fiber fabric 102.

  As shown in FIG. 1, the described process may be controlled by a control unit 140 (such as a processor, a portion of a processor, or multiple processors). The control unit 140 is one of the various units shown in FIG. 1, in particular one of the metering unit 113, the mixing unit 119, the fiber forming unit 124, the coagulation unit 128, the additional processing unit 134, the dissolving unit 120, the cleaning unit 180, etc. Configured to control one or more operations. Accordingly, the control unit 140 (e.g., by executing computer-executable program code and / or executing user-defined control commands) controls process parameters by which the nonwoven cellulosic fiber fabric 102 is manufactured. It can be specified accurately and flexibly. Design parameters in this context include air flow along orifice 126, characteristics of coagulating fluid 106, drive speed of fiber support unit 132, composition of lyocell spinning solution 104, temperature and / or pressure, and the like. Additional design parameters that may be adjusted to adjust the properties of the non-woven cellulosic fiber fabric 102 include the number and / or mutual distance and / or geometric arrangement of the orifices 126, the chemical composition and concentration of the Lyocell spinning solution 104, and the like. Is. Thereby, the properties of the non-woven cellulosic fiber fabric 102 can be appropriately adjusted as described below. Such tunable properties (see detailed description below) include the following properties: diameter and / or diameter distribution of fibers 108, amount and / or area of merging between fibers 108, fiber 108. Purity level, properties of multilayer fabric 102, optical properties of fabric 102, fluid retention and / or fluid release properties of fabric 102, mechanical stability of fabric 102, surface smoothness of fabric 102, cross-sectional shape of fibers 108, etc. One or more of these may be included.

  Although not shown, each spinning jet 122 may include a polymer solution inlet through which the lyocell spinning solution 104 is supplied to the jet 122. A gas stream 146 can be applied to the lyocell spinning solution 104 via an air inlet. From the interaction chamber inside the jet 122, bounded by the jet housing, the lyocell spinning solution 104 moves downwards (by the gas stream 146 pulling the lyocell spinning solution 104 downwards) through the respective orifices 126. Is accelerated and narrows laterally under the influence of the gas stream 146, so that as the Lyocell spinning solution 104 moves downwards with the gas stream 146 in the environment of the coagulation fluid 106, it continuously taper. Filaments or cellulosic fibers 108 are formed.

  Accordingly, the process involved in the manufacturing method described with reference to FIG. 1 may include lyocell spinning solution 104, which may also be referred to as a cellulosic solution, being shaped to form liquid strands or latent filaments, which may be liquid strands or The latent filament is drawn by the gas stream 146, significantly reducing its diameter and increasing its length. Partial coagulation of the latent filaments or fibers 108 (or their preforms) with the coagulating fluid 106 before or during web formation on the fiber support unit 132 may also be included. The filaments or fibers 108 may be formed into the web-like fabric 102, washed, dried and optionally further processed (see additional processing unit 134). The filaments or fibers 108 can be collected, for example, on a rotating drum or belt, which forms a web.

  As a result of the manufacturing process described and the choice of solvent used in particular, the fiber 108 has a copper content of less than 5 ppm and a nickel content of less than 2 ppm. This advantageously improves the purity of the fabric 102.

  Lyocell solution sprayed webs (ie, non-woven 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 web is 5 to 300 g / m ² , preferably 10 to 80 g / m ² .
(Ii) The thickness of the web according to the WSP 120.6 standard (respectively DIN 29073) (especially the latest version effective on the priority date of the present patent application) is 0.05-10.0 mm, preferably 0.1-2.5 mm. Is.
(Iii) The specific toughness of the web in MD according to EN29073-3 (respectively ISO9073-3) (especially the latest edition effective as of the priority date of the present patent application) is 0.1-3.0 Nm ² / g, preferably Is in the range of 0.4 to 2.3 Nm ² / g.
(Iv) The average elongation of the web according to EN29073-3 (respectively ISO9073-3) (especially the latest edition effective on the priority date of the present patent application) is in the range of 0.5 to 100%, preferably 4 to 50%. Is.
(V) The MD / CD toughness ratio of the web is 1-12.
(Vi) The water retention of the web according to DIN 53814 (particularly the latest version effective on the priority date of the present patent application) is 1-250%, preferably 30-150%.
(Vii) The water retention capacity of the web according to DIN 53923 (particularly the latest edition valid as of the priority date of the present patent application) is in the range 90-2000%, preferably 400-1100%.
(Viii) Metal residue levels with a copper content of less than 5 ppm and a nickel content of less than 2 ppm according to EN 15587-2 for substrate degradation and EN 17294-2 standard for ICP-MS analysis.

  Most preferably, the Lyocell solution sprayed web exhibits any of the above properties (i) to (viii).

As explained, the process of manufacturing the non-woven cellulosic fiber fabric 102 preferably comprises:
(A) Extruding a solution containing cellulose dissolved in NMMO (see 104) through an orifice 126 of at least one jet 122, thereby forming filaments of the Lyocell spinning solution 104.
(B) Stretching the filaments of the Lyocell spinning solution 104 by a gas flow (see 146).
(C) Contacting the filaments with a steam mist, which preferably contains water (see 106), thereby at least partially precipitating the fibers 108. As a result, the filaments or fibers 108 are at least partially precipitated prior to forming the web or nonwoven cellulosic fiber fabric 102.
(D) Collecting and precipitating the filaments or fibers 108 to form a web or nonwoven cellulosic fiber fabric 102.
(E) Removing the solvent from the cleaning line (see cleaning unit 180).
(F) Optionally, coupling via hydroentanglement, needle punching, etc. (see additional processing unit 134).
(G) Drying and roll collection.

  The components of the non-woven cellulosic fiber fabric 102 may be bonded by merging, incorporation, hydrogen bonding, physical bonding, such as hydroentanglement or needle punching, and / or chemical bonding.

  For further processing, the non-woven cellulosic fiber fabric 102 comprises one or more layers of the same and / or other materials, such as (not shown), a layer of synthetic polymer, cellulose fluff pulp, cellulose or synthetic polymer fibers. Non-woven webs, composite fibers, cellulosic pulp webs such as air-laid or wet laid pulps, high tenacity fiber webs or fabrics, hydrophobic materials, high performance fibers (such as temperature resistant or flame retardant materials), final It may be combined with layers that impart altered mechanical properties to the product (such as layers of polypropylene or polyester), biodegradable materials (eg, films, fibers or webs derived from polylactic acid), and / or high bulk materials.

  It is also possible to combine several distinct layers of non-woven cellulosic fiber fabric 102. See, for example, FIG.

  Nonwoven cellulosic fiber fabric 102 may consist essentially of cellulose. Alternatively, the non-woven cellulosic fiber fabric 102 may include a mixture of cellulose and one or more other fibrous materials. Further, the non-woven cellulosic fiber fabric 102 may include a bicomponent fiber material. The fibrous material within the non-woven cellulosic fiber fabric 102 may at least partially include a modifier. The modifying substance is, for example, a polymer resin, an inorganic resin, an inorganic pigment, an antibacterial product, nanoparticles, a lotion, a flame retardant product, an absorption improving additive, for example, a super absorbent resin, an ion exchange resin, a carbon compound, for example. , Activated carbon, graphite, carbon for conductivity, X-ray contrast substances, luminescent pigments and dyes.

In conclusion, cellulosic non-woven webs or non-woven cellulosic fiber fabrics 102 produced directly from Lyocell spinning solution 104 enable value-added web performance not possible via staple fiber based methods. This includes the possibility of forming a uniform lightweight web, the possibility of producing a microfiber product, and the possibility of producing continuous filaments or fibers 108 that form the web. Moreover, some manufacturing procedures are no longer required as compared to staple fiber derived webs. Further, the non-woven cellulosic fiber fabric 102 according to an exemplary embodiment of the present invention is biodegradable and is manufactured from sustainably sourced raw materials (ie, wood pulp 110, etc.). The non-woven cellulosic fiber fabric 102 according to the exemplary embodiments of the present invention also has advantages in terms of purity and absorbency. Further, the non-woven cellulosic fiber fabric 102 according to the exemplary embodiments of the present invention has adjustable mechanical strength, stiffness and flexibility. Also, the non-woven cellulosic fiber fabric 102 according to exemplary embodiments of the present invention may be manufactured to have a low weight per area (eg, 10-30 g / m ² ). This technique makes it possible to produce very fine filaments with a diameter of 5 μm or less, especially 3 μm or less. The non-woven cellulosic fiber fabric 102 according to an exemplary embodiment of the present invention also provides a wide range of web aesthetics, such as flat, crispy film, paper, or soft, elastic fabrics. It may be formed in preparation. By adapting the process parameters of the described process, it is further possible to precisely adjust the stiffness and mechanical stiffness or elasticity and flexibility of the non-woven cellulosic fiber fabric 102. This can be adjusted, for example, by adjusting the number of merging positions, the number of layers, or by post-treatment (such as needle punching, hydroentanglement and / or calendering). In particular, producing a nonwoven cellulosic fiber fabric 102 having a relatively low basis weight of up to 10 g / m ² or less to obtain filaments or fibers 108 having a very small diameter (eg, up to 3-5 μm or less). Is possible.

  2, 3 and 4 show experimentally captured images of a non-woven cellulosic fiber fabric 102 according to an exemplary embodiment of the present invention where the merging of individual fibers 108 was achieved by corresponding process control. Show. The oval markers in FIGS. 2-4 show such merged areas where a plurality of fibers 108 are integrally connected to each other. At such merging points, two or more fibers 108 may be interconnected to form a unitary structure.

  5 and 6 show experimentally captured images of non-woven cellulosic fiber fabric 102 according to an exemplary embodiment of the present invention in which swelling of fibers 108 has been achieved, and FIG. 5 shows a dry, unswelled state. The fiber fabric 102 is shown, and FIG. The pore size can be measured in both the states of FIG. 5 and FIG. 6 and can be compared with each other. Calculating the average of 30 measurements, it was possible to determine that the swelling of the fibers 108 in the aqueous medium reduced the pore size to 47% of their initial diameter.

  FIG. 7 shows a non-woven fabric according to an exemplary embodiment of the present invention in which the formation of two superposed layers 200, 202 of fibers 108 has been achieved by a corresponding process design, ie, a serial arrangement of multiple spinnerets. 3 shows an experimentally captured image of cellulosic fiber fabric 102. Two separate but connected layers 200, 202 are indicated by horizontal lines in FIG. For example, an n-layer fabric 102 (n ≧ 2) can be manufactured by arranging n spinnerets or jets 122 in series along the machine direction.

  Specific exemplary embodiments of the invention are described in further detail below.

  FIG. 8 shows an experimentally captured image of a non-woven cellulosic fiber fabric 102 according to an exemplary embodiment of the present invention. In the illustrated embodiment, process control adjusts the merging factor to approximately 100% (more precisely, about 98%). As a result of the extremely high merging factor, the fabric 102 shown in FIG. 8 is a substantially continuous sheet having a hardness comparable to the film. Such fabric 102 has a flat film-like behavior. As can be seen in FIG. 8, the process parameters may be adjusted to adjust the merging to cause the formation of the amount of merging locations 204 such that a substantially continuous filmic fabric 102 is obtained.

  The upper left image of FIG. 8 shows the fabric at a first scale, the first scale being illustrated in the left inset showing a bar showing a length of 500 μm. The lower right image of FIG. 8 shows the fabric at a second scale, which is significantly larger than the first scale. The corresponding bar in the right inset shows a length of 20 μm.

  FIG. 9 shows an experimentally captured image of a non-woven cellulosic fiber fabric 102 according to another exemplary embodiment of the invention. In the illustrated embodiment, the process control adjusts the merge factor to near zero (more precisely less than 2%). Such fabric 102 has a soft, flexible, woven-like behavior. As a result of the very small merging factor, the fabric 102 shown in FIG. 9 is a net of fibers 108 that remain weakly coupled through few merging points 204. However, the fibers 108 are frictionally bonded and entangled with each other over the majority of the fabric 102, rather than being bonded by merging. Nevertheless, as a result, the relatively flexible fabric 102 is preferably held together by the merging location 204, entanglement, friction and interfiber hydrogen bonding.

  The upper left image in FIG. 9 shows the fabric at the same first scale as that of the upper left image in FIG. The lower right image in FIG. 9 shows the fabric at a second scale that is larger than the first scale. The corresponding bar in the right inset shows a length of 20 μm.

  Fabrics with such a small merging factor exhibit a plurality of voids or interstices provided between adjacent fibers. With respect to oil absorption capacity, it may be important whether these voids or interstices have the proper size to accommodate the oil particles. In any case, the oil absorption capacity of the cloth 102 shown in FIG. 9 should be significantly larger than the oil absorption capacity of the cloth 102 shown in FIG.

  10 and 11 show experimentally captured images of two non-woven cellulosic fiber fabrics showing different merging factors. The merging factor of fabric 102 of FIG. 10 is less than the merging factor of fabric 102 of FIG. Therefore, when considering the oil absorption capacity as a function of the merging factor, it is clear that there should be an optimum value of the merging factor between the minimum merging factor and the maximum merging factor when the maximum oil absorbing capacity is desired. There should be.

  FIG. 12 illustrates a portion of an apparatus 100 for making a nonwoven cellulosic fiber fabric 102 composed of two laminates 200, 202 of endless cellulosic fibers 108, according to an exemplary embodiment of the invention. The difference between the device 100 shown in FIG. 12 and the device 100 shown in FIG. 1 is that the device 100 according to FIG. 12 has, as mentioned above, two series with orifices 126 and coagulation units 128 respectively assigned. With the jets 122 aligned with each other. In the embodiments described herein, two coagulation units 128 are assigned to each of the jets 122. In FIG. 12, one coagulation unit 128 is located on the left side of the path of the lyocell spinning solution 104 extending between the jet 122 and the fiber support unit 132, and the other coagulation unit 128 is located on the right side of each of the paths. To do. Considering the movable fiber receiving surface of the conveyor belt type fiber support unit 132, the upstream jet 122 on the left side of FIG. The layer 202 is produced by the downstream jet 122 (see right side of FIG. 12) and the layer 202 is attached to the upper major surface of the previously formed layer 200 so that a bilayer 200, 202 of the fabric 102 is obtained.

  According to FIG. 12, the control unit 140 (which controls the jet 122 and any coagulation unit 128) adjusts the process parameters so that the fibers 108 of the different layers 200, 202 have a fiber diameter of 50% relative to the minimum diameter. It is configured to be different as it exceeds. Adjusting the fiber diameter of the fibers 108 of the layers 200, 202 by the control unit 140 may include adjusting the amount of coagulation fluid 106 that interacts with the lyocell spinning solution 104. In addition, the embodiment of FIG. 12 adjusts the fiber diameter by placing multiple jets 122 having orifices 126 (possibly with different characteristics) in series along the movable fiber support unit 132 to adjust the fiber diameter. Adjust the process parameters of. For example, such different characteristics may be different diameters of orifice 126, different rates of gas flow 146, different amounts of gas flow 146 and / or different pressures of gas flow 146. Although not shown in FIG. 12, the fibers 108 may be further processed after being collected on the fiber support unit 132, for example by hydroentanglement, needle punching, impregnation, steaming with pressurized steam and / or calendering. It is possible.

  Still referring to the embodiment shown in FIG. 12, one or more additional nozzle bars or jets 122 may be provided and arranged in series along the transport direction of the fiber support unit 132. An additional layer 202 of fibers 108 may be deposited on the previously formed layer 200, preferably before the coagulation or curing process of the fibers 108 of the layers 200 and / or layers 202 is completely completed, which results in merging. Multiple jets 122 may be arranged so that they may be triggered. With proper adjustment of the process parameters, this can have a beneficial effect on the properties of the multilayer fabric 102.

  While not wishing to be bound by any particular theory, it is presently believed that the second layer 202 can be considered a reinforcement of the first layer 200 and improves the overall uniformity of the resulting multilayer fabric 102. Has been. This increase in mechanical stability can be further improved by variations in fiber diameter, especially inter-fiber diameter variations and / or intra-fiber longitudinal diameter variations of individual fibers 108. Upon application of deeper (especially punctual) pressure (eg, provided by air or water), the cross-sectional shape of the fibers 108 may be more intentionally distorted, which advantageously further increases mechanical stability. Can increase.

  On the other hand, the intended merging between the fibers 108 of the fabric 102 described in FIG. 12 can be induced to further increase the mechanical stability of the fabric 102. In this context, merging may in particular be the supported point-of-contact adhesion of the contact filaments of the fibers 108, before the completion of the coagulation process of one or both of the fibers 108 to be merged. For example, merging may be facilitated by increasing the contact pressure with a fluid flow (eg, air or water flow). By taking this measure, the strength of the coagulation 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 may be increased.

  The apparatus 100 according to FIG. 12, configured for the manufacture of the multilayer fabric 102, can be used to design the shape and / or diameter or diameter distribution of the fibers 108 and the fiber layers 200, 202 in a number of processes. Implement parameters. This is the result of a series arrangement of multiple jets 122, each of the multiple jets 122 being operable with individually adjustable process parameters.

  The device 100 according to FIG. 12 makes it possible in particular to produce a fabric 102 composed of at least two layers 200, 202 (preferably more than two layers). The fibers 108 of the different layers 200, 202 may have different values of diameter and may be formed in one continuous process. By taking this measure, a very efficient production of the non-woven cellulosic fiber fabric 102 can be ensured, which makes it possible, in particular, to obtain the multilayer fabric 102 in one transport procedure for additional processing. You can move to your destination.

  Due to the defined layer separation of the multilayer fabric 102, it is also possible to later separate the multilayer fabric 102 into different individual layers 200, 202 or different multilayer portions. In accordance with an exemplary embodiment of the invention, intralayer adhesion of fibers 108 in one layer 200, 202 and interlaminar adhesion of fibers 108 between adjacent layers 200, 202 (eg, merging and / or friction generation). Both (by contact) can be adjusted appropriately and individually. Corresponding individual controls for each layer 200, 202 are processed in particular so that the coagulation or curing of the fibers 108 of one layer 202 has already been completed when the other layer 200 of fibers 108 is laid thereon. Adjusting the parameters can be achieved individually.

  FIG. 13 shows a non-woven cellulosic fiber fabric 102 that includes three mesh layers. The first (lower) fibrous network layer is represented by reference numeral 200. The second (intermediate) fiber network layer formed on the first fiber network layer 200 is represented by reference numeral 202. The additional (top) fiber mesh layer formed on the second fiber mesh layer 202 is represented by reference numeral 202 '. As already mentioned above, the fabric 102 may include more than three stacked fiber mesh layers.

  As can be further seen in FIG. 11, the three fiber mesh layers 200, 202, 202 ′ have different thicknesses. The first fiber network layer 200 has a first thickness t1. The second fiber mesh layer 202 has a second thickness t2. The additional fiber mesh layer 202 'has a third thickness t3.

  Note that the term “comprising” does not exclude other elements or steps and the use of the article “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims shall not be construed as limiting the scope of the claims.

[Explanation of symbols]
100: Equipment for producing non-woven cellulose fiber cloth 102: Non-woven cellulose fiber cloth / web cloth 104: Lyocell spinning solution 106: Coagulating fluid 108: Fiber 110: Wood pulp 112: Water container 113: Measuring unit 114 : Storage tank 116: Solvent container 118: Washing unit 119: Mixing unit 120: Dissolution unit 122: Jet 124: Fiber forming unit 126: Orifice 128: Coagulation unit 132: (Conveyor belt type) fiber supporting unit 134: Additional Processing unit 136: Roll 140: Control unit 146: Gas flow 200: Merged layer / first mesh layer 202: Merged layer / second mesh layer 202 ': Merged layer / additional mesh layer 204: Merged position t1, t2 , T3: Layer thickness

In the following, an example of causing a variation of the merge factor is described and visualized in the table below. By varying the coagulation spray flow while using a constant spinning solution (ie, a spinning solution having a constant viscosity), especially a lyocell spinning solution, and a constant gas flow (eg air throughput), into a cellulosic fiber fabric. Different merging factors may be achieved. Thereby, the relationship between the coagulation spray flow and the merging factor, that is, the tendency of the merging behavior (the higher the coagulation spray flow, the lower the merging factor) can be observed. As a result, MD indicates the machine direction and CD indicates the width direction.
Flexibility (measured with a so-called "handle-O-meter", based on the non-woven fabric standard WSP 90.3, described in particular by the known Specific Hand measurement technique, in particular the latest version valid as of the priority date of this patent application) May follow the merging trend described above. For example, the toughness (described by Fmax) according to EN 29073-3 (ISO 9073-3 respectively), in particular the latest version valid on the priority date of the present patent application, may also follow the above-mentioned tendency of merger. Therefore, the flexibility and toughness of the resulting non-woven cellulosic fiber fabric can be adjusted according to the degree of merging (specified by the merging factor).

Claims (14)

In particular, a non-woven cellulose fiber cloth produced directly from a Lyocell spinning solution, wherein the non-woven cellulose fiber cloth comprises:
Comprising a net of substantially endless fibers, wherein the non-woven cellulosic fiber fabric exhibits an oil absorption capacity of at least 1900% by weight,
The nonwoven cellulosic fiber fabric has a unit area mass of less than 150 grams per square meter,
The mesh exhibits a fiber merging factor in the range of 0.5% to 10%,
A non-woven cellulosic fiber fabric, wherein the non-woven cellulosic fiber fabric consists essentially of cellulose. Said non-woven cellulose fiber fabric has a unit area mass of less than 100 grams per square meter, in particular less than 50 grams per square meter, especially less than 20 grams per square meter,
The non-woven cellulose fiber cloth according to claim 1. At least some individual fibers are twisted together and / or at least one other fiber structure is twisted with another fiber structure,
The non-woven cellulose fiber cloth according to claim 1 or 2. The non-woven cellulose fiber fabric exhibits an oil absorption capacity of at least 2100% by weight, in particular at least 2300% by weight, in particular at least 2500% by weight,
The non-woven cellulose fiber cloth according to any one of claims 1 to 3. Each of the different fibers being located at least partially in different layers that are distinguishable,
The non-woven cellulose fiber cloth according to any one of claims 1 to 4. The following features:
Fibers of different layers are integrally connected at at least one inter-layer merging location between said different layers,
Each different of said fibers located at least partly in different layers is different with respect to fiber diameter, in particular with respect to average fiber diameter,
The fibers of the different layers have the same fiber diameter, and in particular have substantially the same average fiber diameter,
The different layers of the fiber network provide different functionalities, wherein said different functionalities include, among other things, different wicking properties, different anisotropic behaviors, different liquid absorption capacities, different cleanability, different optical properties, different The non-woven cellulosic fiber fabric of claim 5, comprising at least one of providing different functionality, including at least one of the group consisting of roughness, different smoothness and different mechanical properties. The fiber networks of different layers have different merging factors,
The non-woven cellulose fiber cloth according to claim 6.   Nonwoven cellulosic fiber fabric according to any one of the preceding claims, wherein the fibers have a copper content of less than 5 ppm and / or a nickel content of less than 2 ppm. A method for directly producing a non-woven cellulose fiber cloth, particularly a non-woven cellulose fiber cloth according to any one of claims 1 to 8, from a lyocell spinning solution, the method comprising:
Extruding the lyocell spinning solution supported by the gas stream into a coagulating fluid atmosphere through a jet having an orifice, thereby forming a substantially endless fiber;
Collecting the fibers on a fiber support unit, thereby forming the non-woven cellulosic fiber fabric,
Adjusting the process parameters of the manufacturing process such that the nonwoven cellulosic fiber fabric exhibits an oil absorption capacity of at least 1900 wt%.
The nonwoven cellulosic fiber fabric has a unit area mass of less than 150 grams per square meter,
The mesh exhibits a merging factor of the fibers in the range of 0.5% to 10%,
The method wherein the non-woven cellulose fiber fabric consists essentially of cellulose. Adjusting the process parameters includes the following features:
After the lyocell spinning solution exits the orifices and before the lyocell spinning solution reaches the fiber support unit, the lyocell spinning solutions are combined by causing an interaction between the lyocell spinning solutions extruded through each of the different orifices. Forming at least part of the location,
Forming at least a portion of the merging position by causing coagulation of at least a portion of the fibers when placed on the fiber support unit after the lyocell spinning solution reaches the fiber support unit,
A plurality of jets having orifices are arranged in series along the fiber support unit that is movable to deposit a first layer of fibers on the fiber support unit and a second layer on the first layer. 10. The method of claim 9, comprising depositing at least one of the fibers and then completing coagulation of at least a portion of the fibers at an interface of these layers.   In particular, by means of at least one of the group consisting of hydroentanglement, needle punching, impregnation, steaming with pressurized steam, and calendering, the fibers and / or the non-woven fabric in situ after collection on the fiber support unit. 11. The method of claim 9 or 10, further comprising the step of further treating the cellulosic fiber fabric. An apparatus for producing a non-woven cellulosic fiber fabric directly from a lyocell spinning solution, in particular for producing a non-woven cellulosic fiber fabric according to any one of claims 1 to 8, said apparatus comprising:
A jet having an orifice configured to extrude the Lyocell spinning solution supported by a gas stream;
A coagulation unit configured to provide a coagulating fluid atmosphere to the extruded Lyocell spinning solution, thereby forming a substantially endless fiber;
A fiber support unit configured to collect the fibers, thereby forming the non-woven cellulosic fiber fabric,
A control unit configured to adjust process parameters such that the non-woven cellulosic fiber fabric exhibits an oil absorption capacity of at least 1900% by weight,
The nonwoven cellulosic fiber fabric has a unit area mass of less than 150 grams per square meter,
The mesh exhibits a merging factor of the fibers in the range of 0.5% to 10%,
A device wherein the non-woven cellulosic fiber fabric consists essentially of cellulose.   Dryer sheets, facial masks, hygiene products, wipes, filters, medical products, geotextiles, agrotextiles, clothing, building technology products, automotive products, furniture and industrial products. 9. The non-woven cellulosic fiber of any one of claims 1 to 8 in at least one of the group consisting of: products related to leisure, beauty, sports or travel, and products related to schools or offices. A method of using cloth.   A product or composite comprising the non-woven cellulose fiber fabric according to any one of claims 1-8.