Nonwoven cellulose fiber fabric, method and device for manufacturing the same, use of the same, and product comprising the same

Abstract

A nonwoven cellulose fiber fabric (102), particularly manufactured directly from lyocell spinning solution (104), wherein the fabric (102) comprises a web structure of substantially endless fibers (108) and at least 0.1% by mass of electromagnetic radiation diffuse particles (220) attached to the fibers (108).

Description

[Technical Field] This invention relates to nonwoven cellulose fiber fabrics, methods for manufacturing nonwoven cellulose fiber fabrics, apparatus for manufacturing nonwoven cellulose fiber fabrics, products or compounds, and methods of using them. [Previous Technology] Lyocell fiber technology relates to the direct dissolution of cellulose wood pulp or other cellulose-based feedstocks in a polar solvent (such as n-methyl morpholine n-oxide, also referred to as "amine oxide" or "AO") to produce a viscous, high-shear thinning solution that can be transformed into a range of usable cellulose-based materials. Commercially, this technology is used to manufacture a family of short cellulose fibers widely used in the textile industry (available from Lenzing AG, Austria, under the trade name TENCEL®). Other cellulose products from Lyocell fiber technology have also been used. Cellulose staple fibers have long served as components for converting into nonwoven webs. However, adapting lyocell fiber technology to directly manufacture nonwoven webs would achieve properties and performance unattainable by current cellulose web products. This can be seen as a cellulose version of the meltblown and spunbond technologies widely used in the synthetic fiber industry, but due to significant technological differences, it is impossible to directly adapt synthetic polymer technology for lyocell fibers. Numerous studies have been conducted to develop techniques for the direct formation of cellulose webs from lyocell fiber 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). Other techniques are disclosed in WO 07 / 124521 A1 and WO 07 / 124522 A1. [Summary of the Invention] The purpose of this invention is to provide cellulose-based fiber fabrics with adjustable optical properties and safe use. For the purposes defined above, nonwoven cellulose fiber fabrics, methods for manufacturing nonwoven cellulose fiber fabrics, apparatus for manufacturing nonwoven cellulose fiber fabrics, products or composites, and methods of use are provided according to the claims of the patent application. According to an exemplary embodiment of the invention, a nonwoven cellulose fiber fabric (particularly solution blown) is provided (which is particularly manufactured directly from lyocell fiber spinning solution (particularly by in-situ process or continuous process that can be performed in a continuous operation production line)), wherein the fabric comprises a web structure of substantially endless fibers and at least 0.1% by mass (particularly at least 0.4% by mass) of electromagnetic radiation diffuse particles attached to the fibers (particularly applied to the outer surface of the fibers and / or embedded therein). According to another exemplary embodiment, a method is proposed for manufacturing nonwoven cellulose fiber fabrics directly from lyocell fiber spinning solution (particularly solution blown), wherein the method comprises extruding the lyocell fiber spinning solution through a nozzle (e.g., a spinning tip) with a spinneret under airflow support into a condensing fluid atmosphere (particularly an atmosphere of dispersed condensing fluid) to form substantially endless fibers, collecting the fibers on a fiber support unit to form a fabric, and adjusting process parameters so that the fabric contains at least 0.1% by mass of electromagnetic radiation diffuse particles attached to the fibers. According to another exemplary embodiment, an apparatus is proposed for manufacturing nonwoven cellulose fiber fabrics directly from lyocell fiber spinning solution (particularly solution blown), wherein the apparatus includes a nozzle configured to extrude the lyocell fiber spinning solution under airflow support, a condensing unit configured to provide a condensing fluid atmosphere for the extruded lyocell fiber spinning solution to form substantially endless fibers, a fiber support unit configured to collect fibers to form a fabric, and a control unit configured to adjust process parameters so that the fabric contains at least 0.1% by mass of electromagnetic radiation diffuse particles connected to the fibers (such as a processor configured to execute code for manufacturing nonwoven cellulose fiber fabrics directly from lyocell fiber spinning solution). According to another exemplary embodiment, a product or compound comprising a fabric having the above-mentioned properties is proposed. According to another embodiment, nonwoven cellulose fiber fabrics having the above properties are used in at least one of the following groups: wipes, filters, hygiene products, medical application products, geotextiles, agricultural fabrics, clothing, building technology products, automotive products, home furnishings, industrial products, beauty, leisure, sports or travel related products, and school or office related products. In this application, the term "nonwoven cellulose fiber fabric" (which may also be interpreted as nonwoven cellulose long fiber fabric) specifically refers to a fabric or web composed of a plurality of substantially endless fibers. The term "substantially endless fiber" specifically means a long fiber that is significantly longer than conventional short fibers. In alternative formulations, the term "substantially endless fiber" specifically means a web formed by long fibers having significantly fewer fiber ends per volume than conventional short fibers. In particular, the amount of fiber ends per volume in the endless fiber fabric according to exemplary embodiments of the invention may be less than 10,000 ends / cm³, particularly less than 5,000 ends / cm³. For example, when short fibers are used as a substitute for cotton, their length may be 38 mm (equivalent to the typical natural length of cotton fibers). Conversely, the length of the substantially endless fibers in the nonwoven cellulose fiber fabric may be at least 200 mm, particularly at least 1000 mm. However, those skilled in the art will recognize that even terminal cellulose fibers possess interruptions, which can be formed during and / or after fiber formation processes. Therefore, nonwoven cellulose fiber fabrics made from substantially terminal cellulose fibers have a significantly lower fiber count by mass compared to nonwoven fabrics made from short fibers of the same denier. Nonwoven cellulose fiber fabrics can be manufactured by spinning multiple fibers and by drawing and stretching these fibers toward a preferred fiber support unit. Thus, a three-dimensional network structure or web of cellulose fibers is formed, constituting a nonwoven cellulose fiber fabric. This fabric can be made from cellulose as the main or sole component. In this application, the term "lyocell spinning solution" may specifically refer to a solvent in which cellulose (e.g., wood pulp or other cellulose-based raw materials) is dissolved (e.g., a polar solution of materials such as N-methylmorpholine (NMMO), "amine oxide," or "AO"). The lyocell spinning solution is a solution, not a melt. Cellulose filaments can be produced from the lyocell spinning solution by reducing the concentration of this solvent, for example, by contacting the filament with water. The process of initially producing cellulose fibers from the lyocell spinning solution may be referred to as coagulation. In the contents of this application, the term "air flow" may specifically denote a flow of gas (such as air) that is substantially parallel to the direction of movement of the cellulose fiber or its preform (i.e., the Lyseer fiber spinning fluid) at the time and / or after it has left the spinning nozzle. In the contents of this application, the term "agglomerated fluid" may specifically denote a non-solvent fluid (i.e., gas and / or liquid, arbitrarily including solid particles) capable of diluting the Lyser fiber spinning fluid and exchanging with a solvent to the extent that the cellulose fiber is formed from the Lyselle fiber filament. For example, such a condensed fluid may be a water mist. In the contents of this application, the term “process parameters” may specifically denote all physical parameters and / or chemical parameters and / or device parameters used in the manufacture of nonwoven cellulose fiber fabrics that have an impact on the properties of the fiber and / or fabric (in particular with respect to the fiber diameter and / or fiber diameter distribution). These process parameters can be adjusted automatically by the control unit and / or manually by the user, thereby tuning or adjusting the properties of the fibers of the nonwoven cellulose fiber fabric. Physical parameters that have an influence on the properties of the fibers (especially their diameter or diameter distribution) can be the temperature, pressure, and / or density of the various media involved in the process (such as leiser fiber spinning fluid, agglomerative fluid, airflow, etc.). The chemical parameters may be the concentration, quantity, pH value of the media involved (such as Leiser fiber spinning fluid, agglomeration fluid, etc.). The device parameters may be the size and / or the distance between the yarn-jet holes, the distance between the yarn-jet holes and the fiber-supported unit, the transport speed of the fiber-supported unit, the provision of one or more in-situ post-treatment units, airflow, and the like. The term "fiber" may specifically denote an elongated piece of material comprising cellulose, such as a roughly circular or irregular cross-section that fits arbitrarily with other fibers. The fibers may have an aspect ratio greater than 10, in particular greater than 100, and more particularly greater than 1000. The aspect ratio is the ratio between the length of the fiber and the diameter of the fiber. The fibers may be interconnected by merging (to form an overall multi-fiber structure) or by friction (so as to keep the fibers separate but by weak mechanical coupling of the frictional forces exerted by those fibers in physical contact with each other when they move with each other) to form a network structure. The fibers may be substantially cylindrical, however they may be straight, bent, twisted, or curved. The fibers may consist of a single uniform material (i.e., cellulose). However, the fiber may also contain one or more additives. Liquid materials (such as water or oil) accumulate between the fibers. In this document, "nozzle with spinnerets" (which may be referred to as "arrangement of spinnerets") can be any structure that includes an arrangement of linearly arranged spinnerets. In this application, the term "electromagnetic radiation diffuse particles" specifically refers to solid pigments configured to efficiently scatter electromagnetic radiation. In other words, electromagnetic radiation diffuse particles diffusely reflect electromagnetic radiation due to strong scattering or bending of the electromagnetic radiation emitted by the particles. When sufficient amounts or concentrations of electromagnetic radiation diffuse particles are present, most of the electromagnetic radiation of the corresponding wavelength striking the particles will be reflected. Therefore, the fabric exhibits, for example, opacity. In particular, opacity can be imparted when electromagnetic radiation diffuse particles operating in the visible light range of 400 nm to 800 nm are incorporated into nonwoven cellulose fiber fabrics (which, under certain conditions, especially when wet), can impart opacity. It is also possible that electromagnetic radiation diffuse particles efficiently scattering light impart whiteness and / or brightness to nonwoven cellulose fiber fabrics. However, in certain embodiments, electromagnetic radiation diffuser particles can also operate in the invisible wavelength range: for example, electromagnetic radiation diffuser particles can be those that can efficiently scatter electromagnetic radiation in the infrared range (especially in the wavelength range between 800 nm and 1 mm) and / or the ultraviolet range (especially in the wavelength range between 100 nm and 400 nm) and / or the X-ray range (especially in the wavelength range between 1 pm and 250 pm). According to the exemplary embodiment, a nonwoven cellulose fiber fabric containing diffuse electromagnetic radiation particles that diffuse electromagnetic radiation is provided. This allows the fabric to be opaque in a suitable wavelength range, for example, by selecting the specific properties of the diffuse electromagnetic radiation particles. Related to the properties of cellulose-based fabrics with no end-fibers in the visible light range, enriching the fibers with visible light diffuse particles makes the fabric opaque when wet. Optically transparent wet fabrics are undesirable for certain applications (such as clothing). Related to the properties of the fabric in the ultraviolet range, opacity to UV radiation is advantageous for other applications (such as sun protection in clothing). Even in the X-ray or gamma radiation range, absorption of this radiation by the fabric can be beneficial for providing radiation protection or detection, for example, in medical applications. Advantageously, electromagnetic radiation diffuse particles can be stably incorporated into the fabric by dispersing them in an operating fluid used to manufacture nonwoven cellulose fiber fabrics. This operating fluid can be a spinning solution or lyocell spinning solution, an airflow used to stretch the lyocell spinning solution during fiber formation, a coagulating fluid that promotes fiber deposition, etc. Since particles can easily detach from the fabric and cause harm (e.g., considering health problems associated with inhalable dust), it is highly advantageous for the particles to be strongly bound to or even embedded within the fibers of the fabric. By connecting, binding, or securing at least partially integrated particles to the fibers (particularly by adhering the particles to the outer surface of the fiber and / or completely embedding the particles within the fiber) rather than simply accommodating unconnected fibers within the hollow spaces of the fabric, it is possible to effectively prevent the corresponding particles from detaching from the fabric during use. This ensures safe operation of the fabric when used by a human user, who is thus protected from exposure to detached fine particles. [Simplified Explanation of the Diagram] The present invention will be described below with reference to examples of embodiments, but the invention is not limited thereto: FIG1 illustrates an apparatus according to an exemplary embodiment of the present invention for manufacturing nonwoven cellulose fiber fabrics by means of a coagulating fluid directly forming from a coagulating lyocell fiber spinning solution. Figures 2 to 4 show experimental images of nonwoven cellulose fiber fabrics of the present invention, in which the merging of individual fibers is completed through special process control. Figures 5 and 6 show experimental images of nonwoven cellulose fiber fabrics in an embodiment of the present invention, wherein the fiber expansion has been completed. Figure 5 shows the fiber fabric in a dry, unexpanded state, and Figure 6 shows the fiber fabric in a moist, expanded state. Figure 7 shows an experimental image of a nonwoven cellulose fiber fabric according to an exemplary embodiment of the present invention, wherein the formation of the superimposed layer of two fibers has been accomplished by a special method of implementing two series-connected nozzle strips. Figure 8 shows a graph illustrating the relationship between the particle size (plotted along the horizontal axis) and the relative light scattering ability (plotted along the vertical axis) of rutile titanium dioxide particles in a nonwoven cellulose fiber fabric that is an exemplary embodiment of the present invention. Figure 9 illustrates the basic unit cell of rutile titanium dioxide used as electromagnetic radiation diffuse particles in a nonwoven cellulose fiber fabric according to an exemplary embodiment of the present invention. Figure 10 illustrates the basic unit cell of anatase titanium dioxide used as electromagnetic radiation diffuse particles in a nonwoven cellulose fiber fabric according to another exemplary embodiment of the present invention. Figure 11 illustrates the procedures performed during the execution of a method for manufacturing nonwoven cellulose fiber fabrics using electromagnetic radiation diffuse particles implemented according to an exemplary embodiment of the present invention. Figure 12 illustrates an apparatus for manufacturing nonwoven cellulose fiber fabrics according to an exemplary embodiment of the present invention, which is particularly suitable for integrating electromagnetic radiation diffuse particles into nonwoven cellulose fiber fabrics. The illustrations in the diagrams are for illustrative purposes only. The same reference symbols are used for similar or identical elements in different diagrams.

Implementation Method

Claims

1. A nonwoven cellulose fiber fabric (102) directly manufactured from a lyocell spinning solution (104), wherein the fabric (102) comprises a network structure of substantially endless fibers (108) and electromagnetic radiation diffuse particles (220) in a concentration ranging from 0.1% to 15% by mass, wherein the electromagnetic radiation diffuse particles (220) are attached to the fibers (108), and wherein 50% to 100% of the electromagnetic radiation diffuse particles (220) are attached to the surface of the fibers (108).

2. The fabric (102) of claim 1, wherein the fabric (102) contains electromagnetic radiation diffuse particles (220) in a concentration ranging from 0.1% by mass to 4% by mass.

3. The fabric (102) of claim 1 or 2 includes at least one of the following features: wherein the electromagnetic radiation diffuse particles (220) are configured to diffuse electromagnetic radiation within at least one wavelength range selected from the group consisting of visible light, infrared light, ultraviolet light, and X-rays; wherein the electromagnetic radiation diffuse particles (220) include at least one of the group consisting of: silicates, magnesium oxide, magnesium hydrosilicate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, titanium dioxide, barium sulfate, calcium carbonate, boron nitride, silicon dioxide, and zinc oxide.

4. The fabric (102) of the first or second claim of the patent application, wherein the diameter of the electromagnetic radiation diffuse particles (220) in the range of 80% to 100% is in the range of 70 nm to 3000 nm.

5. The fabric (102) of the first or second claim of the patent application, wherein the copper content of the fiber (108) is in the range of 0 ppm to 5 ppm and / or the nickel content is in the range of 0 ppm to 2 ppm.

6. The fabric (102) of the first or second claim of the patent application, wherein 80% to 100% of the electromagnetic radiation diffuse particles (220) are in rutile and / or anatase state.

7. The fabric (102) of claim 1 or 2 includes at least one of the following features: wherein 50% to 100% of the electromagnetic radiation diffuse particles (220) are embedded in the fiber (108); wherein 50% to 100% of the electromagnetic radiation diffuse particles (220) are spherical; wherein the electromagnetic radiation diffuse particles (220) have a refractive index of more than 1.

5.

8. The fabric (102) of claim 1 or 2, wherein the electromagnetic radiation diffuse particles (220) are configured to make the fabric (102) opaque in the wet state of the fabric (102).

9. The fabric (102) of claim 1 or 2, wherein at least a portion of the electromagnetic radiation diffuse particles (220) have photocatalytic activity.

10. A method for directly producing a nonwoven cellulose fiber fabric (102) from a lyocell fiber spinning solution (104), wherein the method comprises extruding the lyocell fiber spinning solution (104) through at least one nozzle (122) having a spinneret (126) into a condensing fluid (106) atmosphere supported by an airflow (146) to form substantially endless fibers (108); collecting the fibers (108) on a fiber support unit (132) to form the fabric (102); and adjusting process parameters to make the fabric (102) contain a concentrated... Electromagnetic radiation diffuse particles (220) in the range of 0.1% to 15% by mass, wherein the electromagnetic radiation diffuse particles (220) are connected to the fiber (108), wherein the airflow (146) is rich in at least a portion of the electromagnetic radiation diffuse particles (220), thereby providing a fabric (102) having the electromagnetic radiation diffuse particles (220), and / or wherein the condensed fluid (106) is rich in at least a portion of the electromagnetic radiation diffuse particles (220), thereby providing a fabric (102) having the electromagnetic radiation diffuse particles (220).

11. The method of claim 10, comprising at least one of the following features: wherein at least a portion of the electromagnetic radiation diffuse particles (220) are operatively interacting with the lyocell fiber spinning solution (104) prior to completion of coagulation; wherein the lyocell fiber spinning solution (104) upstream of the spinneret (126) is enriched with at least a portion of the electromagnetic radiation diffuse particles (220) to provide a fabric (102) having the electromagnetic radiation diffuse particles (220); wherein the collected fibers (108) are subjected to a washing process to wash out the electromagnetic radiation diffuse particles (220) that are only weakly connected to the fibers (108) from the fabric (102).

12. The method of claim 10 or 11, wherein the method further comprises, after being collected on the fiber support unit (132), further processing the fiber (108) and / or the fabric (102) in situ.

13. An apparatus (100) for directly producing a nonwoven cellulose fiber fabric (102) from a lyocell fiber spinning solution (104), wherein the apparatus (100) comprises: at least one nozzle (122) having a spinneret (126) configured to extrude the lyocell fiber spinning solution (104) under the support of an airflow (146); a condensing unit (128) configured to provide a condensing fluid (104) atmosphere for the extruded lyocell fiber spinning solution (104) to form substantially endless fibers (108); and a fiber support unit (132) configured to collect the fibers (108) to form the fabric (102). The control unit (140) is configured to adjust process parameters so that the fabric (102) contains electromagnetic radiation diffuse particles (220) in the range of 0.1% to 15% by mass, wherein the electromagnetic radiation diffuse particles (220) are connected to the fiber (108), wherein the airflow (146) is rich in at least a portion of the electromagnetic radiation diffuse particles (220), thereby providing a fabric (102) having the electromagnetic radiation diffuse particles (220), and / or wherein the condensate fluid (106) is rich in at least a portion of the electromagnetic radiation diffuse particles (220), thereby providing a fabric (102) having the electromagnetic radiation diffuse particles (220).

14. Use of a nonwoven cellulose fiber fabric (102) as claimed in any one of claims 1 to 9, for use in at least one of the following groups: wipes, dryer sheets, filters, hygiene products, medical application products, geotextiles, agrotextiles, clothing, building technology products, automotive products, furnishings, industrial products, beauty, leisure, sports or travel related products, and school or office related products.

15. A product comprising a fabric (102) as described in any one of claims 1 to 9 of the patent application.

Images