A device for producing cellulose filament nonwoven material

Abstract

The present invention relates to the field of nonwoven technology, and discloses a cellulose filament nonwoven material production device, which comprises a fiber forming unit, a random web forming unit, and a fiber web reinforcement unit connected in sequence according to the direction of material conveying; the fiber forming unit comprises a spinneret assembly, an upper coagulation bath channel, a lower coagulation bath channel, and a web support curtain connected in sequence, as well as a coagulation bath storage box connected to the upper coagulation bath channel and the lower coagulation bath channel; the upper coagulation bath channel is vertically arranged directly below the outlet of the spinneret assembly, and the lower coagulation bath channel is arranged above the web support curtain. The production device of the present invention can produce a uniform filament fiber web, which can solve the problems of incomplete diffusion of cellulose solvent, low cellulose crystallinity, affecting material strength, and difficulty in forming a random web of cellulose filaments in the preparation of existing cellulose filament nonwoven materials.

Description

Technical Field

[0001] The invention relates to the technical field of nonwovens, in particular to a production device for cellulose filament nonwoven materials. Background Art

[0002] Cellulose is a widely available renewable resource in nature. Not only is its stockpile enormous, but with 7 billion tons of new cellulose generated annually, it is virtually inexhaustible. Regenerated cellulose fiber can replace synthetic fibers produced from petroleum. Its abundant supply, excellent performance, and widespread availability can effectively alleviate the global energy crisis.

[0003] Currently, regenerated cellulose nonwovens are primarily made from viscose staple fibers. However, the production process produces large amounts of toxic and hazardous wastewater and exhaust gases, hindering the development of viscose nonwovens. Therefore, finding safer and more reliable cellulose dissolution systems and processes to eliminate pollution at the source has long been a goal.

[0004] The successful development of Tencel (Lyocell) fiber offers a near-perfect technology. Using N-methylmorpholine-N-oxide (NMMO) as a solvent, it is a regenerated cellulose fiber produced through a dry-jet wet spinning process without chemical reactions. Lyocell fiber is environmentally friendly, emits no harmful substances, and is naturally biodegradable. Furthermore, the organic solvent NMMO used in the production process is 99.5% recyclable and reusable, making it extremely low in toxicity and environmentally friendly. Existing Tencel (Lyocell) nonwovens are mostly made from Lyocell staple fibers, which are carded into a web and then hydroentangled. However, this staple fiber nonwoven process is complex and expensive. Nonwoven fabrics produced directly from cellulose filaments offer the advantages of a shorter process, reduced energy consumption, and lower product cost.

[0005] Patent application number WO2021170608A1 discloses a method and device for manufacturing spunbonded nonwoven fabrics. The preparation method is as follows: a cellulose solution containing a solvent is sprayed out through a nozzle hole and stretched to form filaments. The filaments are solidified by air flow and then deposited on a perforated conveying device to form a fiber web. The fiber web is washed with a solvent, reinforced with hydroentanglement, and dried to make a spunbonded nonwoven fabric.

[0006] After analysis, the shortcomings of the above scheme are: First, the cellulose filaments are coagulated by airflow. Since the contact time between the condensing airflow and the cellulose filaments is short, the solvent in the cellulose solution is not thoroughly diffused, resulting in the cellulose filaments being only "partially coagulated", making it difficult to obtain a complete and uniform structure, reducing the crystallinity of cellulose and affecting the fiber strength; second, in this scheme, the cellulose filaments after water washing directly enter the hydroentanglement reinforcement, and the filaments are arranged longitudinally in the material, resulting in low transverse strength of the material, affecting product application.

[0007] At present, the fiber raw materials for filament webs are mainly synthetic fibers such as polypropylene and polyester. Cellulose filament non-woven materials have not yet been industrialized and their technical research is very limited.

[0008] In summary, from the current technical research point of view, the technical problems of uneven solvent diffusion and insufficient coagulation in the preparation of non-woven materials using Tencel (Lyocell) filaments have not been solved; in addition, since the prepared cellulose filaments have strong directionality, it is not easy to form a random web in the subsequent process, resulting in a large difference in the longitudinal and transverse breaking strength of the filament non-woven materials, especially the low transverse breaking strength of the material, which seriously affects the application and promotion of the product. Summary of the Invention

[0009] In order to solve the problems of incomplete diffusion of cellulose solvent, low cellulose crystallinity, affecting material strength and difficulty in forming a disordered web of cellulose filaments in the preparation of cellulose filament non-woven materials, the present invention provides a cellulose filament non-woven material production device. The production device of the present invention can prepare a uniform filament fiber web, solving the problem of insufficient lateral strength of cellulose filament non-woven materials.

[0010] The specific technical solution of the present invention is: a cellulose filament nonwoven material production device, which includes a fiber forming unit, a random web forming unit and a fiber web reinforcement unit connected in sequence according to the direction of the conveying material.

[0011] The fiber forming unit includes a spinneret assembly, an upper coagulation bath channel, a lower coagulation bath channel and a support net curtain connected in sequence, and a coagulation bath storage box connected to the upper coagulation bath channel and the lower coagulation bath channel; the upper coagulation bath channel is vertically arranged directly below the outlet of the spinneret assembly, and the lower coagulation bath channel is arranged above the support net curtain (the lower coagulation bath channel is composed of the upper surface of the support net curtain and the lower surface of the coagulation bath storage box).

[0012] Preferably, the solvent concentration in the upper coagulation bath channel is lower than the solvent concentration in the lower coagulation bath channel, the temperature of the upper coagulation bath channel is lower than the temperature of the lower coagulation bath channel, and the flow rate of the liquid in the upper coagulation bath channel is higher than the spinning speed and lower than the flow rate of the liquid in the lower coagulation bath channel.

[0013] Preferably, the spinneret assembly comprises a spinneret and an air gap device located below the spinneret.

[0014] Preferably, the supporting net curtain and the lower coagulation bath channel are arranged to be inclined upward along the traveling direction and the horizontal plane.

[0015] In the same space, the inclined setting will provide more space for the dewatering box inside the net support curtain. For a single dewatering box, the space above it becomes smaller and smaller along the fiber web support and conveying direction. If the flow rate of the dewatering box is controlled to be the same, the flow rate of the coagulation liquid will become faster and faster.

[0016] Preferably, the tilt angle is 10 to 25 degrees.

[0017] Preferably, a transfer roller is provided at the junction of the lower coagulation bath channel and the upper coagulation bath channel.

[0018] The transfer roller is used to transfer the spinning stream from the upper coagulation bath channel to the lower coagulation bath channel.

[0019] Preferably, the net curtain includes an endlessly rotating conveying net and a plurality of net curtain guide rollers for driving the conveying net; and a plurality of dehydrators facing the lower coagulation bath channel are provided below the portion of the conveying net corresponding to the lower coagulation bath channel.

[0020] Preferably, a fiber web stripping device is provided at the output end of the supporting mesh curtain, comprising an air blowing head located below the conveying mesh and a corresponding adsorption roller located above the conveying mesh, and the air blowing head faces the adsorption roller.

[0021] The above arrangement is used to smoothly transfer the filament fiber web from the supporting curtain to the random web forming unit.

[0022] Preferably, the random web-forming unit includes a first nozzle, a second nozzle, a first web-forming curtain, a second web-forming curtain and a washing device; the first nozzle and the first web-forming curtain are sequentially arranged above the conveying material; the second nozzle and the second web-forming curtain are sequentially arranged below the conveying material; the first web-forming curtain and the second web-forming curtain rotate in opposite directions to achieve the purpose of clamping the conveying material while it moves; the washing device is located downstream of the first web-forming curtain and the second web-forming curtain.

[0023] Preferably, the airflow of the first nozzle is directed toward the upper surface of the conveying material and opposite to the surface of the second mesh curtain; the airflow of the second nozzle is directed toward the lower surface of the conveying material and opposite to the surface of the first mesh curtain.

[0024] Preferably, the first nozzle and the second nozzle can realize reciprocating motion in the transverse direction of the conveying material surface.

[0025] Preferably, the first web-forming curtain and the second web-forming curtain respectively include a web-forming curtain conveying net that rotates endlessly and a plurality of web-forming curtain guide rollers for transmitting the web-forming curtain conveying net.

[0026] Preferably, a first suction device is provided on the inner side of the first web-forming curtain opposite to the airflow of the second nozzle; and a second suction device is provided on the inner side of the second web-forming curtain opposite to the airflow of the first nozzle.

[0027] Preferably, the washing device includes a plurality of corresponding liquid spray heads and liquid removers, which are respectively arranged on the upper and lower sides of the conveying material.

[0028] Preferably, according to the traveling direction of the conveying material, the liquid outlet of the deliquidator located in the rear channel is connected to the liquid inlet of the liquid spray head located in the front channel.

[0029] Preferably, a pre-consolidation device is provided downstream of the washing device; the pre-consolidation device comprises pre-jelly heads and a third suction device respectively provided on the upper and lower sides of the second web-forming curtain.

[0030] Preferably, the fiber web reinforcement unit is a hydroentanglement reinforcement mechanism.

[0031] The working process of the above-mentioned production device is as follows: the cellulose spinning solution is ejected from the spinneret, cooled and stretched by the air gap device, and then vertically enters the upper coagulation bath channel; the spinning stream is first solidified under the low-speed, low-temperature, and low-concentration coagulation bath state; the spinning stream is deposited on the support net curtain, and the spinning stream is introduced into the lower coagulation bath channel through the transfer roller; under the high-speed, high-temperature, and high-concentration coagulation bath state, the bidirectional diffusion of the cellulose solvent is completed through the joint action of the inclined upward support net curtain, the dehydrator, etc., and the cellulose stream is further stretched and solidified to form a cellulose filament network. The cellulose filament web is blown and adsorbed by the stripping device and then transferred from the web supporting curtain to the random web forming unit; the cellulose filament web is fed into the middle of the first nozzle and the second nozzle through the guide roller; the first nozzle and the second nozzle both reciprocate in the transverse direction of the filament web and spray airflow on the upper and lower surfaces of the cellulose filament web. With the cooperation of the first suction device and the second suction device, the cellulose filament web is adsorbed onto the surface of the first web forming curtain and the second web forming curtain, and forms a random distribution in the transverse direction; the randomized filament web is clamped by the first web forming curtain and the second web forming curtain and washed by multiple liquid spray heads and a de-liquidator to remove residual solvent in the fiber web; and then is fed into the spunlace system for reinforcement to form the cellulose filament non-woven material.

[0032] Specifically, a method for preparing a cellulose filament nonwoven material comprises the following steps:

[0033] (1) Cellulose pulp is mixed with a solvent to dissolve the cellulose and prepare a spinning solution.

[0034] (2) The spinning solution is extruded from the spinneret to form a spinning stream, which is then cooled and stretched in the air gap; the spinning stream is passed through multiple liquid coagulation baths to allow the solvent to diffuse and the cellulose stream to solidify, thereby forming a cellulose bundle.

[0035] Each liquid coagulation bath in the multiple liquid coagulation baths has a different solvent concentration, temperature and flow rate; wherein: the solvent concentration in the liquid coagulation bath in the upper section is lower than the solvent concentration in the liquid coagulation bath in the lower section, the temperature of the liquid coagulation bath in the upper section is lower than the temperature of the liquid coagulation bath in the lower section, and the flow rate of the liquid coagulation bath in the upper section is higher than the spinning speed and lower than the flow rate of the liquid coagulation bath in the lower section.

[0036] The technical effects of the above settings are:

[0037] First, the present invention uses a low solvent concentration in the upper liquid coagulation bath to effectively reduce the occurrence of doubling, thereby reducing defects caused by the chaotic web formation process. However, excessively low solvent concentrations increase the double diffusion rate between the cellulose solvent and the non-solvent, leading to excessive surface coagulation and the formation of a solid skin. This slows the coagulation rate of the inner fiber layer, affecting fiber quality. Therefore, the use of a low solvent concentration in the upper liquid coagulation bath requires a low coagulation bath temperature to stabilize double diffusion.

[0038] Secondly, after the segmented coagulation bath is set, the present invention further stretches the spinning stream by the coagulation bath fluid speed of different stages. First, it passes through the coagulation bath with low speed flow to reduce the disturbance inside the fluid. The spinning stream can be smoothly stretched and solidified in the coagulation bath channel located in the upper section, reducing the generation of parallel yarns. The spinning stream forms a nascent fiber, which makes the fiber have a certain strength. Then it contacts and impacts the coagulation bath with high speed flow to complete the coagulation bath located in the next section. The coagulation process is more sufficient and uniform. The segmented coagulation bath is set, and the coagulation bath parameters can be dynamically adjusted in sections. When the cellulose solvent concentration in the coagulation bath is too high, the fiber structure is imperfect due to the small flux, resulting in low fiber strength. At the same time, when the cellulose solvent concentration in the coagulation bath is too low, the solvent diffuses too fast, which easily causes the surface layer to solidify rapidly, the structure to become dense, and then the double diffusion is blocked. The multi-stage differentiated coagulation bath uses coagulation baths of different concentrations and temperatures according to the different coagulation stages of the spinning solution in the coagulation bath to achieve the best coagulation effect.

[0039] (3) The cellulose filaments are deposited and randomly arranged into a disordered filament fiber network.

[0040] (4) Wash the filament fiber web with water to remove residual solvent.

[0041] (5) reinforcing the filament fiber web to produce the cellulose filament nonwoven material.

[0042] Preferably, in step (3): the cellulose filaments are deposited onto a supporting screen, the solvent is removed, and the filament web is blown by air flow to scatter the filaments to form a disordered filament web.

[0043] The present invention adopts high-speed airflow to spray on the upper and lower surfaces of the filament fiber web, clamps the fiber web and impacts the receiving net curtain. The obtained filament fiber web has a good disorder effect, can effectively improve the transverse breaking strength of the cellulose filament non-woven material, and can solve the technical problem that the filament non-woven material is not easy to be disordered into a web.

[0044] Preferably, in step (4), the conveying speed of the filament fiber web is lower than the output speed of the fiber web obtained after deposition in step (3).

[0045] Designing the delivery speed of the resulting filament web to be slower than the delivery speed of the deposited web facilitates the stacking of the filaments in both the longitudinal and transverse directions, enhancing the disordered effect of the filament web and effectively controlling the material weight. If the delivery speed of the filament web is greater than or equal to the delivery speed of the deposited web, the airflow will not produce the disordered effect, and the filaments will be stretched longitudinally, preventing effective entanglement between the filaments during the subsequent hydroentanglement process.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) The present invention stretches and solidifies cellulose thin streams through multiple coagulation bath channels. The entire coagulation process is uniform and sufficient. The obtained cellulose has high crystallinity and a compact structure. The fiber network structure skeleton is fine and has a high density. The prepared cellulose filament non-woven material has high strength, increased modulus, and low elongation, which solves the technical problems of uneven solvent diffusion and insufficient coagulation in the cellulose filament fiber network.

[0048] (2) The multi-stage coagulation method of the present invention can effectively reduce the occurrence of filament doubling, thereby reducing defects caused by the disordered web laying process and improving product quality. Because the coagulation bath conditions vary in different coagulation stages, the process adjustment is more diversified, which is conducive to the production of more uniform and variable performance cellulose filament nonwoven materials.

[0049] (3) The present invention uses high-speed airflow to spray on the upper and lower surfaces of the filament fiber web, so that the fiber web hits the receiving mesh curtain. The resulting filament fiber web has a good disorder effect, which can effectively improve the transverse breaking strength of the cellulose filament non-woven material, and solve the technical problem that the filament non-woven material is not easy to be disordered into a web.

[0050] (4) The present invention adopts a coagulation-randomization-water washing process, which can effectively improve the efficiency of water washing and reduce water consumption and equipment footprint.

[0051] (5) The present invention can realize automatic guiding and stretching of filament fiber webs by rationally designing a production device for cellulose filament nonwoven materials, which is more conducive to automated control and can greatly reduce the maintenance time of equipment during production and shutdown. The device has a compact structure, small footprint, simple operation and low investment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a structural schematic diagram of a device for producing cellulose filament nonwoven materials.

[0053] The figures are marked as: fiber forming unit 1, random web forming unit 2, fiber web reinforcement unit 3, spinning fine stream 4, filament fiber web 5, cellulose filament non-woven material 6, spinneret assembly 101, web curtain 102, upper coagulation bath channel 103, lower coagulation bath channel 104, coagulation bath storage box 105, transfer roller 106, conveying net 107, web curtain guide roller 108, dewatering device 109, blowing head 110, adsorption roller 111, washing device 201, first air jet 202, second air jet 203, first web curtain 204, second web curtain 205, web curtain guide roller 206, first suction device 207, second suction device 208, liquid spray head 209, deliquidator 210, pre-spinning head 211, third suction device 212, web curtain conveying net 213. DETAILED DESCRIPTION

[0054] The present invention will be further described below with reference to the embodiments.

[0055] Overall embodiment

[0056] A cellulose filament nonwoven material production device comprises a fiber forming unit 1, a random web forming unit 2 and a fiber web reinforcement unit 3 connected in sequence according to the direction of the conveying material.

[0057] The fiber forming unit comprises a spinneret assembly 101, an upper coagulation bath channel 103, a lower coagulation bath channel 104, and a support net curtain 102, all connected in sequence, as well as a coagulation bath storage tank 105 connected to the upper and lower coagulation bath channels. The spinneret assembly includes a spinneret and an air gap device located below the spinneret. The upper coagulation bath channel is vertically positioned directly below the outlet of the spinneret assembly, while the lower coagulation bath channel is positioned above the support net curtain. A transfer roller 106 is provided at the junction of the lower and upper coagulation bath channels. Furthermore, after solvent diffusion, the solvent concentration in the upper coagulation bath channel is lower than that in the lower coagulation bath channel, the temperature in the upper coagulation bath channel is lower than that in the lower coagulation bath channel, and the flow rate of the liquid in the upper coagulation bath channel is higher than the spinning speed but lower than that in the lower coagulation bath channel. The support net curtain and the lower coagulation bath channel are arranged at an angle upward from the horizontal plane along the direction of travel, preferably at an angle of 10 to 25 degrees. The support screen consists of an endlessly rotating conveyor screen 107 and several screen guide rollers 108 for driving the screen. Below the portion of the conveyor screen corresponding to the lower coagulation bath channel, several dewatering devices 109 are located, facing the lower coagulation bath channel. A fiber web stripping device is located at the output end of the support screen. This device comprises an air blow head 110 located below the conveyor screen and a corresponding suction roller 111 located above the conveyor screen, with the air blow head facing the suction roller.

[0058] The random web-forming unit includes a first air jet 202, a second air jet 203, a first web-forming curtain 204, a second web-forming curtain 205, and a washing device 201. The first and second web-forming curtains each include an endlessly rotating web-forming curtain conveyor net 213 and a plurality of web-forming curtain guide rollers 206 for driving the web-forming curtain conveyor nets. The first air jet and the first web-forming curtain are positioned sequentially above the conveying material; the second air jet and the second web-forming curtain are positioned sequentially below the conveying material. The first and second web-forming curtains rotate in opposite directions to clamp the conveying material. The airflow from the first air jet is directed toward the upper surface of the conveying material, facing the surface of the second web-forming curtain; the airflow from the second air jet is directed toward the lower surface of the conveying material, facing the surface of the first web-forming curtain. Simultaneously, the first and second air jets can reciprocate transversely across the conveying material surface. A first suction device 207 is located on the inside of the first web-forming curtain, facing the airflow from the second air jet; a second suction device 208 is located on the inside of the second web-forming curtain, facing the airflow from the first air jet. The washing unit, located downstream of the first and second web-forming curtains, comprises several corresponding spray heads 209 and de-liquidators 210, positioned above and below the conveying material. Furthermore, the outlet of the de-liquidator in the trailing channel is connected to the inlet of the spray head in the preceding channel, in the direction of the conveying material. Furthermore, a pre-consolidation device is located downstream of the washing unit, comprising pre-spinning heads 211 and a third suction device 212, positioned above and below the second web-forming curtain, respectively.

[0059] Fiber web reinforcement unit: It is a hydroentanglement reinforcement mechanism.

[0060] A method for preparing a cellulose filament nonwoven material comprises the following steps:

[0061] (1) Cellulose pulp is mixed with a solvent to dissolve the cellulose, thereby preparing a spinning solution with a temperature of 75 to 95°C and a cellulose concentration of 7 to 12 wt%.

[0062] (2) The spinning solution is extruded from the spinneret to form a spinning stream, which is then cooled and stretched in an air gap. The spinning stream is passed through multiple liquid coagulation baths to allow the solvent (preferably N-methylmorpholine oxide) to diffuse and the cellulose stream to solidify, thereby forming a cellulose tow.

[0063] Wherein, each section of the multi-section liquid coagulation bath has a different solvent concentration, temperature and flow rate; wherein: the solvent concentration in the liquid coagulation bath located in the upper section is lower than the solvent concentration in the liquid coagulation bath located in the lower section, the temperature of the liquid coagulation bath located in the upper section is lower than the temperature of the liquid coagulation bath located in the lower section, and the flow rate of the liquid coagulation bath located in the upper section is higher than the spinning speed and lower than the flow rate of the liquid coagulation bath located in the lower section.

[0064] Preferably, the multi-stage liquid coagulation bath comprises an upper and lower liquid coagulation bath, wherein the solvent in the coagulation bath is an aqueous solution of N-methylmorpholine oxide; wherein: the concentration of N-methylmorpholine oxide in the upper liquid coagulation bath is 16-22 wt %, the temperature of the upper liquid coagulation bath is 15-22° C., and the flow rate of the upper liquid coagulation bath is 40-100 m / min; the concentration of N-methylmorpholine oxide in the lower liquid coagulation bath is 20-25 wt %, the temperature of the lower liquid coagulation bath is 20-30° C., and the flow rate of the lower liquid coagulation bath is 50-150 m / min.

[0065] (3) The cellulose filaments are deposited on a support curtain to remove the solvent, and are blown toward the filament web by an air flow (the air flow contains a coagulation bath with a flow rate of 15 to 80 m / s) to form a disordered filament web.

[0066] (4) The filament fiber web is supported and transported (the transport speed is lower than the output speed of the fiber web obtained after deposition in step (3), and the preferred speed ratio is 0.1 to 0.8:1), and then washed with water using a multi-stage washing method to remove residual solvent in the filament fibers.

[0067] (5) The washed filament fiber web is reinforced (preferably by hydroentanglement), dried, and rolled to produce the cellulose filament nonwoven material.

[0068] The cellulose filament nonwoven material prepared by the above method comprises mutually entangled cellulose filaments; the fineness of the cellulose filaments is 0.9 to 1.8 dtex; the unit area mass of the cellulose filament nonwoven material is 15 to 60 g / m 2 .

[0069] Example 1

[0070] A cellulose filament nonwoven material production device, such as Figure 1 As shown, according to the direction of the conveying material, it includes a fiber forming unit 1, a random web forming unit 2 and a fiber web reinforcement unit 3 connected in sequence.

[0071] The fiber forming unit comprises a spinneret assembly 101, an upper coagulation bath channel 103, a lower coagulation bath channel 104, and a support net curtain 102, all connected in sequence, as well as a coagulation bath storage tank 105 connected to the upper and lower coagulation bath channels. Specifically, the spinneret assembly includes a spinneret and an air gap device located below the spinneret. The upper coagulation bath channel is vertically positioned directly below the spinneret assembly outlet, corresponding to the spinneret assembly outlet. The coagulation bath enters the upper inlet of the upper coagulation bath channel. The lower coagulation bath channel is formed by the upper surface of the support net curtain and the lower surface of the coagulation bath storage tank. The support net curtain and the lower coagulation bath channel are arranged upwardly and at an inclination angle of 18° relative to the horizontal plane along the direction of travel. The inlet of the lower coagulation bath channel is connected to the outlet of the upper coagulation bath channel; a transfer roller 106 is provided at the junction of the lower and upper coagulation bath channels. The support screen consists of an endlessly rotating conveyor screen 107 and two guide rollers 108 for the screen. Five parallel dewatering devices 109, facing the lower coagulation bath channel, are located below the conveyor screen. A fiber web stripping device is located at the output end of the support screen, consisting of an air blower 110 below the conveyor screen and a corresponding suction roller 111 above the conveyor screen, with the air blower facing the suction roller.

[0072] The random web-forming unit includes a first air jet 202, a second air jet 203, a first web-forming curtain 204, a second web-forming curtain 205, and a washing device 201. Specifically, the first and second web-forming curtains each include an endlessly rotating web-forming curtain transport net 213 and four web-forming curtain guide rollers 206 for transmitting the web-forming curtain transport net. The first air jet and the first web-forming curtain are positioned sequentially above the filament web 5; the second air jet and the second web-forming curtain are positioned sequentially below the filament web. The first and second web-forming curtains rotate in opposite directions to clamp the filament web. The airflow from the first air jet is directed toward the upper surface of the filament web, opposite the surface of the second web-forming curtain; the airflow from the second air jet is directed toward the lower surface of the filament web, opposite the surface of the first web-forming curtain. Simultaneously, the first and second air jets can reciprocate transversely across the surface of the filament web. A first suction device 207 is installed on the inner side of the first web-forming curtain, opposite the airflow from the second nozzle; a second suction device 208 is installed on the inner side of the second web-forming curtain, opposite the airflow from the first nozzle. The washing device, located downstream of the first and second web-forming curtains, comprises three pairs of corresponding spray heads 209 and de-liquidators 210, positioned on the upper and lower sides of the filament web. Furthermore, the liquid outlet of the de-liquidator located in the rear channel is connected to the liquid inlet of the spray head located in the front channel, in the direction of travel. Furthermore, a pre-consolidation device is installed downstream of the washing device, comprising pre-spinning heads 211 and a third suction device 212, positioned on the upper and lower sides of the second web-forming curtain, respectively.

[0073] Fiber web reinforcement unit: It is a hydroentanglement reinforcement mechanism.

[0074] The working process of the above-mentioned production device is as follows: the cellulose spinning solution is ejected from the spinneret, cooled and stretched by the air gap device, and then vertically enters the upper coagulation bath channel 103; the spinning stream 4 is solidified under the low-speed, low-temperature, low-concentration coagulation bath state; the spinning stream 4 is deposited on the support net curtain 102, and the spinning stream 4 is introduced into the lower coagulation bath channel 104 through the transfer roller 106; under the high-speed, high-temperature, high-concentration coagulation bath state, the two-way diffusion of the cellulose solvent is completed through the joint action of the inclined upward support net curtain 102, the dehydrator 109, etc., and the cellulose stream 4 is further stretched and solidified to form a cellulose filament web 5; the cellulose filament web 5 is transferred from the support net curtain 102 to the random web forming unit 2 after blowing and adsorption by the stripping device; the cellulose filaments The web 5 is fed into the middle of the first nozzle 202 and the second nozzle 203 via the guide roller; the first nozzle 202 and the second nozzle 203 both reciprocate in the transverse direction of the filament web 5, and perform air jets on the upper and lower surfaces of the cellulose filament web 5. With the cooperation of the first suction device 207 and the second suction device 208, the cellulose filament web 5 is adsorbed onto the surface of the first web-forming curtain 204 and the second web-forming curtain 205, and forms a disorderly distribution in the transverse direction; the disordered filament web 5 is clamped by the first web-forming curtain 204 and the second web-forming curtain 205, and is washed by multiple liquid spray heads 209 and a de-liquidator 210 to remove residual solvent in the fiber web; and then is fed into the hydroentanglement system for reinforcement to form a cellulose filament non-woven material 6.

[0075] The above-mentioned cellulose filament nonwoven material has a mass per unit area of ​​45g / m 2 The nonwoven material is composed of cellulose filaments entangled with each other, wherein the fineness of the cellulose filaments is 1.2 dtex. The preparation method of the cellulose filament nonwoven material specifically comprises the following steps:

[0076] (1) Cellulose pulp was mixed with an aqueous solution of N-methylmorpholine oxide (NMMO) to dissolve the cellulose and prepare a spinning solution; the mass concentration of cellulose in the spinning solution was 10 wt%; the temperature of the spinning solution was 85 °C;

[0077] (2) The spinning solution is extruded from the spinneret to form a spinning stream 4, which is cooled and stretched in an air gap; the spinning stream 4 is passed through two liquid coagulation baths to diffuse the solvent and solidify the cellulose stream to form a cellulose tow;

[0078] The concentration of N-methylmorpholine oxide (NMMO) in the upper liquid coagulation bath is 20 wt %, and the temperature of the upper coagulation bath is 20° C. The concentration of N-methylmorpholine oxide (NMMO) in the lower liquid coagulation bath is 22 wt %, and the temperature of the lower liquid coagulation bath is 25° C. The flow rate of the coagulation bath in the upper liquid coagulation bath is 70 m / min, and the flow rate of the coagulation bath in the lower liquid coagulation bath is 100 m / min.

[0079] (3) Depositing the cellulose tow onto a support curtain at a conveying speed of 50 m / min, removing the solvent, and forming a filament fiber web; then, the filament fiber web is disordered by air flow (the air flow is blown toward the front and back sides of the filament fiber web and moves back and forth along the lateral direction of the filament fiber web), and a disordered filament fiber web 5 is formed; wherein the air flow speed is 30 m / s;

[0080] (4) The filament web after being disorganized is received and transported by a web curtain, wherein the web curtain transport speed is 25 m / min, and the filament web 5 is washed with water three times to remove the residual solvent in the filament fibers;

[0081] (5) The washed filament fiber web is subjected to hydroentanglement, drying, and rolling to form a 45g / m 2 Cellulose filament nonwoven material6.

[0082] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art; the methods used in the present invention are conventional methods in the art unless otherwise specified.

[0083] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A device for producing cellulose filament nonwoven materials, characterized in that: According to the direction of the conveying material, it includes a fiber forming unit, a random web forming unit and a fiber web reinforcement unit connected in sequence; The fiber forming unit includes a spinneret assembly, an upper coagulation bath channel, a lower coagulation bath channel and a support net curtain connected in sequence, and a coagulation bath storage box connected to the upper coagulation bath channel and the lower coagulation bath channel; the upper coagulation bath channel is vertically arranged directly below the outlet of the spinneret assembly, and the lower coagulation bath channel is arranged above the support net curtain; The solvent concentration in the upper coagulation bath channel is lower than the solvent concentration in the lower coagulation bath channel, the temperature of the upper coagulation bath channel is lower than the temperature of the lower coagulation bath channel, and the flow speed of the liquid in the upper coagulation bath channel is higher than the spinning speed and lower than the flow speed of the liquid in the lower coagulation bath channel; A transfer roller is provided at the junction of the lower coagulation bath channel and the upper coagulation bath channel.

2. The production device according to claim 1, characterized in that: The supporting net curtain and the lower coagulation bath channel are arranged upwardly and inclined along the traveling direction and the horizontal plane.

3. The production device according to claim 2, characterized in that: The tilt angle is 10-25 degrees.

4. The production device according to claim 1, characterized in that: The supporting net curtain comprises an endlessly circulating conveying net and several supporting net curtain guide rollers for driving the conveying net. Several dehydrators facing the lower coagulation bath channel are provided below the portion of the conveying net corresponding to the lower coagulation bath channel.

5. The production device according to claim 4, characterized in that: The output end of the supporting net curtain is provided with a fiber web stripping device, which includes an air blowing head located below the conveying net and a corresponding adsorption roller located above the conveying net, and the air blowing head faces the adsorption roller.

6. The production device according to claim 1, characterized in that: The random web-forming unit includes a first air jet head, a second air jet head, a first web-forming curtain, a second web-forming curtain and a washing device; the first air jet head and the first web-forming curtain are sequentially arranged above the conveying material; the second air jet head and the second web-forming curtain are sequentially arranged below the conveying material; the first web-forming curtain and the second web-forming curtain rotate in opposite directions to achieve the purpose of clamping the conveying material while it moves; the washing device is located downstream of the first web-forming curtain and the second web-forming curtain.

7. The production device according to claim 6, characterized in that: The airflow of the first nozzle is directed toward the upper surface of the conveying material and opposite to the surface of the second mesh curtain; the airflow of the second nozzle is directed toward the lower surface of the conveying material and opposite to the surface of the first mesh curtain.

8. The production device according to claim 7, characterized in that: The first nozzle and the second nozzle can realize reciprocating motion in the transverse direction of the conveying material surface.

9. The production device according to claim 7, characterized in that: A first suction device is provided on the inner side of the first web-forming curtain opposite to the airflow of the second nozzle; a second suction device is provided on the inner side of the second web-forming curtain opposite to the airflow of the first nozzle.

10. A method for preparing a cellulose filament nonwoven material using the production apparatus according to any one of claims 1 to 9, comprising: 1) Mixing cellulose pulp with a solvent to dissolve the cellulose and prepare a spinning solution; 2) The spinning solution is extruded from the spinneret to form a spinning stream, which is then cooled and drawn in an air gap. The spinning stream passes through multiple liquid coagulation baths to diffuse the solvent and solidify the cellulose stream to form a cellulose tow. 3) Deposition and randomization of cellulose tows into a disordered filament web; 4) Washing the filament fiber web to remove residual solvent; 5) reinforcing the filament fiber web to produce the cellulose filament nonwoven material.

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