Viscose-based short fiber solid felt wet forming process and system

Abstract

The invention provides a viscose-based short fiber solid felt wet forming process and system, and relates to the technical field of solid felt wet forming, and the process comprises the following steps: immersing a wet felt blank into an adjustable overflow sizing tank, applying a phenolic resin glue solution, removing redundant glue solution through a stainless steel suction box, then feeding into a multi-section curing oven, and drying and curing in sections at 120-200 DEG C to obtain the viscose-based short fiber solid felt. The humidity in the multi-section curing oven is controlled to be 10%-30%. The wet felt blank is fed into a multi-section curing oven, the material gradually adapts to the curing environment in the preheating section and is prepared for subsequent curing, the main curing section is rapidly heated through a natural gas burner, the main curing process of the material is achieved, and it is ensured that the performance of the material is stably improved, and the material is slowly cooled in the cooling section, so that internal stress caused by sudden temperature drop is avoided; optimal treatment can be achieved in all stages, the product quality is effectively guaranteed, and the problems that the temperature control precision of a conventional curing oven is poor, and the material buckling deformation risk is increased are solved.

Description

Technical Field

[0001] The invention relates to the technical field of wet-forming solid felt, and in particular to a process and system for wet-forming solid felt based on viscose staple fibers. Background Art

[0002] Viscose staple fibers are regenerated fibers made from natural cellulose, and have the characteristics of good hygroscopicity and softness. Viscose staple fiber felting refers to the process of consolidating staple fibers into felt-like materials by physical or chemical methods, using steps such as wet felt blank molding and drying and curing. Wet molding is the key link in felting.

[0003] In the prior art, when viscose-based staple fiber felt is wet-formed, the staple fibers are prone to flocculation during the traditional wet forming process, which directly leads to unstable fluctuations in the density of the formed felt material and causes quality problems such as uneven fiber distribution. In addition, during the curing process, the temperature control accuracy of conventional curing furnaces is poor, which increases the risk of material warping and deformation, and may also cause residual glue, significantly reducing the curing efficiency. During the shredding process of the staple fibers, since the staple fiber material itself is relatively soft, the blades for the shredding operation need to operate at a high frequency, resulting in some long fibers not being effectively cut off, affecting the uniformity and quality of the staple fiber shredding. Summary of the invention

[0004] The present invention relates to a viscose-based staple fiber solid felt wet forming process and system, so as to solve the problem that in the traditional wet forming process, the staple fibers are prone to flocculation, which directly leads to unstable fluctuations in the density of the formed felt material and causes quality problems such as uneven fiber distribution. In addition, in the curing process, the temperature control accuracy of the conventional curing furnace is poor, which increases the risk of material warping and deformation, and may also cause residual glue, significantly reducing the curing efficiency.

[0005] The present invention provides a viscose-based staple fiber solid felt wet forming process and system, which specifically comprises the following steps: 1. Pretreatment: Cut the viscose-based long fibers into short fibers with a length of 5-20 mm by a blade, and carry out gradient pre-oxidation treatment in a vacuum tube furnace. In the first stage, the temperature is raised to 200-220°C at 5-10°C / min and kept for 10-20 minutes. In the second stage, the temperature is raised to 260-300°C and kept for 30-60 minutes. 2. Slurry preparation: the pretreated short fibers, nanocellulose reinforcing agent and dispersant are mixed at a mass ratio of 80-90:5-10:0.1-0.5, and water is added and stirred in an ultrasonic dispersion tank to form a slurry with a solid content of 8%-12%. The stirring rate is 300-500rpm, and ultrasonic dispersion with a frequency of 20-50kHz is simultaneously applied; 3. Wet forming: The slurry is fed into the stratified headbox, and the slurry is spread in layers through the inclined section and the horizontal section with an inclination angle of 5°-15°. The fan blades in the air-drying dehydration component device are used for preliminary dehydration to form a wet felt blank with a moisture content of 40%-60%; 4. Gluing and curing: Immerse the wet felt blank into an adjustable overflow glue tank, apply phenolic resin glue with a mass concentration of 12%-18%, remove excess glue through a stainless steel suction box at a negative pressure of -0.03--0.08MPa, and then send it to a multi-stage curing furnace for segmented drying and curing at 120-200℃. The humidity in the multi-stage curing furnace is controlled at 10%-30%; 5. Post-processing: The cured felt is cut into preset sizes by a laser slitting machine with a slitting accuracy of ±0.2mm, and surface defect detection and automated packaging based on machine vision are performed.

[0006] Furthermore, the stratified headbox in step 3 includes: a bottom headbox, a guide plate array is provided at the outlet of the bottom headbox, the guide plate spacing is 3-8 mm, and the inclination angle is adjustable; a secondary headbox, a honeycomb flow splitter and rectifier is provided inside the secondary headbox, the honeycomb aperture is 2-4 mm, and the surface is coated with polytetrafluoroethylene to reduce fiber adhesion; The air-drying and dehydration assembly device in step three adopts a vacuum negative pressure and mechanical pressure roller collaborative dehydration method, wherein the vacuum dehydration pressure is negative 0.06-negative 0.09MPa, the dehydration time is 10-30s, the mechanical pressure roller is a silicone coated roller, the line pressure is 80-120N / cm, and the roller surface temperature is 50-80℃.

[0007] Furthermore, the multi-stage curing furnace in step 4 is divided into three sections: Preheating stage: 120-140℃, humidity 30%-50%, residence time 5-8min; Main curing stage: 160-180℃, humidity ≤20%, residence time 20-25min; Cooling section: 80-100℃, humidity 40%-60%, residence time 3-5min, and the cooling section adopts circulating air cooling and spray water cooling composite cooling.

[0008] Furthermore, the preparation method of the nanocellulose reinforcing agent is: hydrolyzing wood pulp fibers with sulfuric acid and then centrifuging and purifying them to obtain nanocellulose with a diameter of 20-50nm and an aspect ratio of ≥100, and the addition amount thereof is 5%-8% of the mass of the short fibers.

[0009] Furthermore, the laser cutting machine in step 5 adopts CO 2 Laser, wavelength 10.6μm, power 200-500W, slitting speed 10-30m / min, dynamic adjustment error of winding tension ≤1N.

[0010] Furthermore, it includes: a fixed frame, an operation panel is installed on one side of the fixed frame, and the operation panel includes: a DCS system and an edge computing module; a protective support plate is installed on the top of the fixed frame; a driving motor is installed on the outer side of the protective support plate, and a transmission wheel is installed on the output end of the driving motor, and the transmission wheel is rotatably installed on the inner side of the protective support plate, and a conveyor belt is installed on the inner side of the protective support plate, wherein the conveyor belt is installed on the transmission wheel on the inner side of the protective support plate; a deflector is installed on the side end of the protective support plate; an air outlet net is installed on the side end of the air deflector, wherein a plurality of air outlet holes are evenly distributed on the air outlet net; a deflector carrier is installed on the inner bottom of the deflector, an air inlet hood is installed on the outer bottom of the deflector, and a driving cylinder is installed on the top of the deflector , a blade is installed at the output end of the driving cylinder; the blade is movably installed on the guide carrier; a rotating part is rotatably installed on the inner side of the side end of the protective support plate; a gear is installed on the side end of the rotating part through the side end of the protective support plate, and an air outlet groove is provided on the outer side of the rotating part; a servo motor is installed on the outer side of the protective support plate, and a gear is installed on the output end of the servo motor, and the gear is meshed with the gear on the side end of the rotating part; partition plates are evenly distributed on the inner side of the rotating part; a positioning tube is installed on the side end of the protective support plate; the inner end of the positioning tube is rotatably installed inside the rotating part, the positioning tube is rotatably installed on the side of the partition plate, and a guide groove is provided on the outer side of the positioning tube; an air-conditioning pump is installed on the outer side of the protective support plate, and a mainstream pipe is installed on the output end of the air-conditioning pump.

[0011] Furthermore, the side end of the main pipe is connected with a shunt pipe; the side end of the shunt pipe is connected with the side end of the positioning pipe, and a plurality of guide pipes are installed on the outside of the shunt pipe; the side end of the guide pipe is connected with the side of the air inlet hood; a vacuum tube furnace is installed at the bottom of the guide hood; an ultrasonic dispersion tank is installed on the top of the fixed frame; the ultrasonic dispersion tank is located below the output end of the vacuum tube furnace, an ultrasonic generator is installed in the ultrasonic dispersion tank, and two feed hoods are installed on the top of the ultrasonic dispersion tank; a stratified headbox is installed on the top of the fixed frame; the feed end of the stratified headbox is connected with the discharge end of the ultrasonic dispersion tank.

[0012] Furthermore, the stratified headbox includes a bottom headbox, a secondary headbox and an Internet of Things sensor, and an adjustable overflow gluing trough is installed at the output end of the stratified headbox; a multi-stage curing furnace is installed on the side of the adjustable overflow gluing trough, and a guide rail is installed on the inner side of the adjustable overflow gluing trough and the multi-stage curing furnace; a forming plate is slidably installed on the inner side of the guide rail; the forming plate is slidably installed on the inner side of the adjustable overflow gluing trough and the multi-stage curing furnace; an air-drying and dehydration component device is installed on the upper end of the guide rail; the air-drying and dehydration component device includes a vacuum negative pressure component and a mechanical pressure roller component.

[0013] Furthermore, an Internet of Things sensor is installed on the inner side of the adjustable overflow glue tank, and a suction box is installed on the outer side of the adjustable overflow glue tank; a heat transfer oil circulation pipeline is installed on the inner bottom of the multi-stage curing furnace; a natural gas burner is installed on the top of the fixed frame; the natural gas burner is installed on one side of the multi-stage curing furnace; a recovery pipe is installed on the top of the multi-stage curing furnace; a collecting pipe is installed on the side end of the recovery pipe; and the side end of the collecting pipe is connected to the vacuum tube furnace.

[0014] Furthermore, a cutting table is installed at the discharge end of the multi-stage curing furnace; a forming plate is slidably installed on the cutting table, and a laser slitting machine is installed on the top of the cutting table; a reclaimed water reuse component is installed on the outer side of the adjustable overflow sizing tank; the black liquor recovery and processing component on the reclaimed water reuse component is connected to the air drying and dehydration component device, and a reflux pipe is installed at the output end of the reclaimed water reuse component; the side end of the reflux pipe is installed on the side of the ultrasonic dispersion tank.

[0015] The present invention provides a viscose-based staple fiber solid felt wet forming process and system, which has the following beneficial effects: When the present invention is used, the pretreated short fibers are mixed with a nanocellulose reinforcing agent and a dispersant in a specific mass ratio. The addition of the nanocellulose reinforcing agent can effectively enhance the bonding force between the fibers and improve the strength and toughness of the fiber products. The dispersant can promote uniform dispersion of the fibers and avoid fiber agglomeration, thereby further optimizing the overall performance of the fiber products. By precisely controlling the solid content, it is ensured that the slurry has good fluidity and adhesion, meets the requirements of subsequent processing technology, and improves the quality stability of the product. Stirring is performed to initially mix the components evenly, while ultrasonic dispersion utilizes its cavitation effect, mechanical effect, and thermal effect to further break up the fiber agglomerates, promote the uniform adsorption of the nanocellulose reinforcing agent and the dispersant on the fiber surface, significantly improve the uniformity of fiber distribution, and improve the quality of the product.

[0016] In addition, the wet felt blank is sent into a multi-stage curing furnace, and precise temperature and humidity parameters are set according to the characteristics of different stages. In the preheating section, the material gradually adapts to the curing environment and prepares for subsequent curing. The main curing section uses a natural gas burner to quickly heat up to achieve the main curing process of the material, ensuring that the material performance is steadily improved. The cooling section slowly cools the material to avoid internal stress caused by a sudden drop in temperature. This segmented drying and curing method ensures that the material can be optimally processed at each stage, effectively ensuring product quality and avoiding problems such as material warping and deformation and residual glue. Precise temperature control reduces energy waste, improves energy utilization efficiency, and achieves energy-saving and efficient production goals.

[0017] The cold air generated by the cold air pump flows through the main flow pipe and the branch pipe into the positioning pipe, flows out through the guide groove, and then passes through the rotating part space separated by the partition plate and the air outlet groove to cool the long fibers moving on the guide carrier at the bottom and sides. The cold air also flows through the guide pipe into the air intake hood, and cools the long fibers at the top through the slots on the guide carrier, so that the upper and lower sides of the long fibers are cooled at the same time, the texture becomes brittle, and the long fibers are completely cut off, which is convenient for subsequent shredding operations, further improving the shredding effect, and improving the quality of wet-process solid felt forming. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0019] The drawings described below are only related to some embodiments of the present invention, but are not intended to limit the present invention.

[0020] In the attached picture: Figure 1 The module block diagram of the overall forming process flow of the present invention is shown; Figure 2 The overall structural schematic diagram of the present invention is shown; Figure 3 A schematic diagram of the three-dimensional structure of the bottom of the air deflector of the present invention is shown; Figure 4 A schematic diagram of the three-dimensional structure of the air intake hood of the present invention is shown; Figure 5 A schematic diagram of the three-dimensional structure of the rotating member of the present invention is shown; Figure 6 A schematic cross-sectional structural diagram of a rotating member of the present invention is shown; Figure 7 A schematic diagram of the three-dimensional structure of the vacuum tube furnace of the present invention is shown; Figure 8 A schematic diagram of the bottom three-dimensional structure of the stratified headbox of the present invention is shown; Fig. 9 A schematic diagram of the three-dimensional structure of the multi-stage curing furnace of the present invention is shown.

[0021] Reference numerals list 1. Fixed frame; 101. Protective support plate; 102. Conveyor belt; 103. Flow guide cover; 104. Air outlet net; 105. Flow guide carrier plate; 106. Blade; 107. Air inlet cover; 108. Rotating member; 109. Separator; 1010. Positioning tube; 1011. Flow guide groove; 1012. Main flow pipe; 1013. Diverter pipe; 1014. Flow guide pipe; 201, vacuum tube furnace; 202, ultrasonic dispersion tank; 203, feed cover; 204, stratified headbox; 301, adjustable overflow glue tank; 302, guide rail; 303, forming plate; 304, air drying and dehydration assembly device; 305, suction box; 306, multi-stage curing furnace; 307, heat transfer oil circulation pipeline; 308, natural gas burner; 309, recovery pipe; 3010, collection pipe; 401, cutting table; 402, laser slitting machine; 501. Recycled water reuse component; 502. Black liquor recovery and treatment component; 503. Reflux pipe. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Please refer to Figures 1 to 9 : Embodiment 1: The present invention proposes a viscose-based staple fiber solid felt wet forming process and system, comprising the following steps: 1. Pretreatment: The viscose-based long fibers are cut into short fibers with a length of 5-20 mm by a blade 106, and subjected to gradient preoxidation treatment in a vacuum tube furnace 201. In the first stage, the temperature is raised to 200-220° C. at a rate of 5-10° C. / min and kept at this temperature for 10-20 min. In the second stage, the temperature is raised to 260-300° C. and kept at this temperature for 30-60 min. Second, slurry preparation: the pretreated short fibers, nanocellulose reinforcing agent and dispersant are mixed at a mass ratio of 80-90:5-10:0.1-0.5, and water is added and stirred in an ultrasonic dispersion tank 202 to form a slurry with a solid content of 8%-12%, the stirring rate is 300-500 rpm, and ultrasonic dispersion with a frequency of 20-50 kHz is simultaneously applied; 3. Wet forming: the slurry is fed into the stratified headbox 204, and the slurry is spread in layers through the inclined section and the horizontal section with an inclination angle of 5°-15°, and the fan blades in the air-drying dehydration component device 304 are used to assist in preliminary dehydration to form a wet felt blank with a moisture content of 40%-60%; Fourth, glue application and curing: the wet felt blank is immersed in an adjustable overflow glue application tank 301, and a phenolic resin glue solution with a mass concentration of 12%-18% is applied. The excess glue solution is removed by a stainless steel suction box 305 at a negative pressure of -0.03--0.08MPa, and then sent to a multi-stage curing furnace 306 for segmented drying and curing at 120-200°C. The humidity in the multi-stage curing furnace 306 is controlled at 10%-30%; 5. Post-processing: The solidified felt is cut into preset sizes by a laser slitting machine 402, with a cutting accuracy of ±0.2 mm, and surface defect detection based on machine vision and automatic packaging are performed.

[0024] The stratified headbox 204 in step 3 includes: a bottom headbox, a guide plate array is provided at the outlet of the bottom headbox, the guide plate spacing is 3-8mm, and the inclination angle is adjustable; a secondary headbox, a honeycomb flow diversion and rectification part is provided inside the secondary headbox, the honeycomb aperture is 2-4mm, and the surface is coated with polytetrafluoroethylene to reduce fiber adhesion; the air-drying dehydration component device 304 in step 3 adopts a vacuum negative pressure and a mechanical pressure roller to coordinate dehydration, wherein the vacuum dehydration pressure is negative 0.06-negative 0.09MPa, the dehydration time is 10-30s, the mechanical pressure roller is a silica gel coated roller, the line pressure is 80-120N / cm, and the roller surface temperature is 50-80°C; the multi-stage type in step 4 The curing furnace 306 is divided into three sections: preheating section: 120-140°C, humidity 30%-50%, residence time 5-8min; main curing section: 160-180°C, humidity ≤20%, residence time 20-25min; cooling section: 80-100°C, humidity 40%-60%, residence time 3-5min, and the cooling section adopts circulating air cooling and spray water cooling composite cooling; the preparation method of the nanocellulose reinforcing agent is: the wood pulp fiber is hydrolyzed with sulfuric acid and then centrifuged and purified to obtain nanocellulose with a diameter of 20-50nm and an aspect ratio of ≥100, and the addition amount is 5%-8% of the mass of the short fiber; the laser slitting machine 402 in step 5 adopts CO 2 Laser, wavelength 10.6μm, power 200-500W, slitting speed 10-30m / min, dynamic adjustment error of winding tension ≤1N.

[0025] Embodiment 2, on the basis of embodiment 1, a viscose-based staple fiber solid felt wet forming system comprises: a fixed frame 1, an operation panel is installed on one side of the fixed frame 1, and the operation panel comprises: a DCS system and an edge computing module; a protective support plate 101 is installed on the top of the fixed frame 1; a driving motor is installed on the outer side of the protective support plate 101, and a transmission wheel is installed on the output end of the driving motor, and the transmission wheel is rotatably installed on the inner side of the protective support plate 101, and a conveyor belt 102 is installed on the inner side of the protective support plate 101, wherein the transmission The belt 102 is installed on the transmission wheel inside the protective support plate 101; the side end of the protective support plate 101 is installed with a guide cover 103; the side end of the guide cover 103 is installed with an air outlet net 104, wherein a plurality of air outlet holes are evenly distributed on the air outlet net 104; a guide carrier plate 105 is installed at the inner bottom of the guide cover 103, an air inlet cover 107 is installed at the outer bottom of the guide cover 103, a driving cylinder is installed at the top of the guide cover 103, and a blade 106 is installed at the output end of the driving cylinder; the blade 106 is movably installed on the guide carrier The protective support plate 101 is provided with a rotating member 108 which is rotatably mounted on the inner side of the side end of the protective support plate 101; the side end of the rotating member 108 penetrates the side end of the protective support plate 101 and is provided with a gear, and an air outlet groove is provided on the outer side of the rotating member 108; a servo motor is installed on the outer side of the protective support plate 101, and a gear is installed on the output end of the servo motor, and the gear meshes with the gear on the side end of the rotating member 108; partition plates 109 are evenly distributed on the inner side of the rotating member 108; a positioning tube 1010 is installed on the side end of the protective support plate 101; the positioning tube The inner end of 1010 is rotatably mounted inside the rotating member 108, the positioning tube 1010 is rotatably mounted on the side of the partition plate 109, and a guide groove 1011 is provided on the outer side of the positioning tube 1010; a cold air pump is installed on the outer side of the protective support plate 101, and a main flow pipe 1012 is installed on the output end of the cold air pump; a shunt pipe 1013 is connected to the side end of the main flow pipe 1012; the side end of the shunt pipe 1013 is connected to the side end of the positioning tube 1010, and multiple guide pipes 1014 are installed on the outer side of the shunt pipe 1013;The side end of the guide pipe 1014 is connected to the side of the air inlet hood 107. When the long fibers are cut into strands in the wet forming process of the viscose-based staple felt, the long fibers to be cut are placed on the conveyor belt 102. The driving motor on the side of the protective support plate 101 drives the transmission wheel to drive the conveyor belt 102 to move, so that the conveyor belt 102 drives the long fibers to move to the rotating member 108. The servo motor on the outside of the protective support plate 101 drives the rotating member 108 to rotate on the outside of the positioning tube 1010 through the gear. The cold air flow generated by the cold air pump on the outside of the protective support plate 101 flows to the inside of the diversion pipe 1013 through the main pipe 1012. The cold air flow enters the inside of the positioning tube 1010 and flows out through the guide grooves 1011 at the bottom and sides. The partition plate 109 allows the rotating member 108 to rotate on the outside of the positioning tube 1010. The interior of 108 is divided into multiple spaces, so that the airflow flows downward through the air outlet slots on the rotating member 108 to cool the long fibers moving on the guide carrier 105. At the same time, the cold airflow in the shunt pipe 1013 enters the interior of the air inlet hood 107 through the guide pipe 1014. The cold airflow cools the long fibers through the slots on the guide carrier 105, so that the upper and lower sides of the long fibers are cooled at the same time, making the long fibers brittle. The drive cylinder on the guide hood 103 drives the blade 106 to move intermittently to cut the long fibers, so that the long fibers are completely cut off, and the fiber cutting quality is improved. The blown airflow carries the cut short fibers downward to the vacuum tube furnace 201, and the excess airflow is discharged through the air holes on the air outlet net 104. ;

[0026] Embodiment 3, on the basis of embodiment 1, a vacuum tube furnace 201 is installed at the bottom of the guide cover 103; an ultrasonic dispersion tank 202 is installed on the top of the fixed frame 1; the ultrasonic dispersion tank 202 is located below the output end of the vacuum tube furnace 201, an ultrasonic generator is installed in the ultrasonic dispersion tank 202, and two feed covers 203 are installed on the top of the ultrasonic dispersion tank 202; a stratified headbox 204 is installed on the top of the fixed frame 1; the feed end of the stratified headbox 204 is connected to the discharge end of the ultrasonic dispersion tank 202; the stratified headbox 204 includes a bottom headbox, a secondary headbox and an Internet of Things sensor, and an adjustable overflow sizing tank 301 is installed at the output end of the stratified headbox 204; the ... A multi-stage curing furnace 306 is installed on the side of the flow glue tank 301, and a guide rail 302 is installed on the inner side of the adjustable overflow glue tank 301 and the multi-stage curing furnace 306; a molding plate 303 is slidably installed on the inner side of the guide rail 302; the molding plate 303 is slidably installed on the inner side of the adjustable overflow glue tank 301 and the multi-stage curing furnace 306; an air-drying and dehydrating component device 304 is installed on the upper end of the guide rail 302; the air-drying and dehydrating component device 304 includes a vacuum negative pressure component and a mechanical pressure roller component; an Internet of Things sensor is installed on the inner side of the adjustable overflow glue tank 301, and a suction box 305 is installed on the outer side of the adjustable overflow glue tank 301; a heat transfer oil circulation pipeline 307 is installed on the inner bottom of the multi-stage curing furnace 306; a fixed A natural gas burner 308 is installed on the top of the frame 1; the natural gas burner 308 is installed on one side of the multi-stage curing furnace 306; a recovery pipe 309 is installed on the top of the multi-stage curing furnace 306; a collecting pipe 3010 is installed on the side end of the recovery pipe 309; the side end of the collecting pipe 3010 is connected to the vacuum tube furnace 201; a cutting table 401 is installed at the discharge end of the multi-stage curing furnace 306; a forming plate 303 is slidably installed on the cutting table 401, and a laser slitting machine 402 is installed on the top of the cutting table 401; a reclaimed water recycling component 501 is installed on the outer side of the adjustable overflow glue tank 301; the black liquor recovery and processing component 502 on the reclaimed water recycling component 501 is connected to the air drying and dehydration component device 304, and the reclaimed water recycling component 501 is connected to the air drying and dehydration component device 304. The output end of the component 501 is provided with a return pipe 503; the side end of the return pipe 503 is provided on the side of the ultrasonic dispersion tank 202. In the wet forming process of the viscose-based staple fiber felt, the shredded staple fibers enter the vacuum tube furnace 201 for gradient oxidation treatment. In the first stage, the temperature is increased to 200-220°C at 5-10°C / min and kept warm for 10-20min; in the second stage, the temperature is increased to 260-300°C and kept warm for 30-60min. The oxidized staple fibers are placed in the ultrasonic dispersion tank 202, and the nanocellulose reinforcing agent and the dispersing agent are placed through the two feeding covers 203, so that the mass ratio of the staple fibers, the nanocellulose reinforcing agent and the dispersing agent is 80-90:5-10:0.1-0.5 for mixing, and then injecting water flow for stirring, the stirring rate is 300-500rpm, stirring to form a slurry with a solid content of 8%-12%, and applying ultrasonic waves with a frequency of 20-50kHz for dispersion treatment, so that the treated slurry enters the stratified headbox 204 for treatment, and the slurry is layered on the forming plate 303 after passing through the stratified headbox 204, so that the forming plate 303 moves along the guide rail 302 and passes through the air-drying dehydration component device 304 for dehydration treatment, forming a wet felt blank with a moisture content of 40%-60%, and the residual liquid generated by dehydration is collected in the black liquor recovery and treatment component 502 for treatment, and the treated residual liquid forms reclaimed water and is stored in the reclaimed water reuse component 501, and then flows to the ultrasonic dispersion tank 202 through the reflux pipe 503 for use as water flow, and the reuse rate is ≥98%, and the wet felt blank then enters the adjustable overflow sizing tank 301 for application The phenolic resin glue with a mass concentration of 12%-18% is sucked by the sensor to remove the excess glue, and the stainless steel suction box 305 is used to remove the excess glue at a negative pressure of -0.03--0.08MPa, and then it is sent to the multi-stage curing furnace 306. The natural gas burner 308 is used to quickly heat up the main curing section. The heat transfer oil circulation pipeline 307 is used to accurately control the temperature of the preheating section and the cooling section. The curing is carried out at 120-200℃ in stages. The humidity in the curing furnace is controlled at 10%-30%. The excess heat generated in the cooling section is collected by the recovery pipe 309 and then enters the vacuum tube furnace 201 through the collection pipe 3010 for recycling. The cured solid felt is moved to the cutting table 401 and cut according to the preset size by the laser slitting machine 402. The cutting accuracy is ±0.2mm, and the surface defect detection and automatic packaging based on machine vision are carried out. .

[0027] The working principle of this embodiment is as follows: the long fibers are placed on the conveyor belt 102, and the conveyor belt 102 drives the long fibers to move to the rotating member 108. The servo motor drives the rotating member 108 to rotate on the outside of the positioning tube 1010 through the gears. The cold air flow generated by the cold air pump on the outside of the protective support plate 101 flows through the main pipe 1012 to the branch pipe 1013 and then enters the positioning tube 1010, flows out through the guide grooves 1011 at the bottom and sides, and flows downwardly through the air outlet grooves on the rotating member 108 to cool the long fibers. At the same time, the cold air flow in the branch pipe 1013 flows through the guide grooves 1011 at the bottom and sides. The tube 1014 enters the air inlet hood 107 and then cools the long fibers through the slots on the guide carrier 105, making the long fibers brittle. The blade 106 moves intermittently to quickly cut the long fibers. The short fibers after shredding enter the vacuum tube furnace 201 for gradient oxidation treatment. In the first stage, the temperature is increased to 200-220°C at 5-10°C / min and kept warm for 10-20min; in the second stage, the temperature is increased to 260-300°C and kept warm for 30-60min. The short fibers are placed in the ultrasonic dispersion tank 202 to make the short fibers, nanocellulose reinforcing agent and dispersant according to mass. The mixture is stirred at a ratio of 80-90:5-10:0.1-0.5 to form a slurry with a solid content of 8%-12%, and ultrasonic waves with a frequency of 20-50kHz are applied for dispersion treatment. The treated slurry enters the stratified head box 204 and is layered on the forming plate 303. The forming plate 303 is dehydrated by the air-drying dehydration component device 304 to form a wet felt blank with a moisture content of 40%-60%. The wet felt blank then enters the adjustable overflow glue tank 301 to apply phenolic resin glue with a mass concentration of 12%-18%, and is then passed through the stainless steel suction box 305 with a phenolic resin glue with a mass concentration of 12%-18%. -0.03--0.08MPa negative pressure is used to remove excess glue, and then it is sent to the multi-stage curing furnace 306. The natural gas burner 308 is used to quickly heat up the main curing section. The heat transfer oil circulation pipeline 307 is used to accurately control the temperature of the preheating section and the cooling section. It is dried and cured in sections at 120-200℃. The humidity in the curing furnace is controlled at 10%-30%. The excess heat generated in the cooling section is collected by the recovery pipe 309 and then enters the vacuum tube furnace 201 through the collection pipe 3010 for recycling. The cured solid felt is moved to the cutting table 401 for slitting and packaging.

[0028] In this article, there are a few points to note: 1. The drawings of the embodiments of the present invention only involve structures related to the embodiments of the present invention, and other structures can refer to the general design.

[0029] 2. In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0030] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A wet forming process for viscose-based staple fiber felt, characterized in that: The following steps are involved: First, the viscose-based long fibers are cut into short fibers with a length of 5-20 mm by a blade (106), and a gradient pre-oxidation treatment is performed in a vacuum tube furnace (201). In the first stage, the temperature is increased to 200-220° C. at a rate of 5-10° C. / min and kept at this temperature for 10-20 minutes. In the second stage, the temperature is increased to 260-300° C. and kept at this temperature for 30-60 minutes. Second, the pretreated short fibers, nanocellulose reinforcing agent and dispersant are mixed in a mass ratio of 80-90:5-10:0.1-0.5, and water is added and stirred in an ultrasonic dispersion tank (202) to form a slurry with a solid content of 8%-12%, the stirring rate is 300-500 rpm, and ultrasonic dispersion with a frequency of 20-50 kHz is simultaneously applied; Third, the slurry is input into the layered headbox (204), and the slurry is layered through the inclined section and the horizontal section with an inclination angle of 5°-15°, and the fan blades in the air-drying dehydration component device (304) are used to assist in preliminary dehydration to form a wet felt blank with a moisture content of 40%-60%; Fourth, the wet felt blank is immersed in an adjustable overflow glue tank (301), and a phenolic resin glue solution with a mass concentration of 12%-18% is applied, and the excess glue solution is removed by a stainless steel suction box (305) at a negative pressure of -0.03--0.08 MPa, and then sent to a multi-stage curing furnace (306), and dried and cured in stages at 120-200° C., and the humidity in the multi-stage curing furnace (306) is controlled at 10%-30%; Fifth, the solidified felt is cut into preset sizes by a laser slitting machine (402) with a cutting accuracy of ±0.2 mm, and surface defect detection based on machine vision and automatic packaging are performed.

2. The wet forming process of viscose-based staple fiber felt according to claim 1, characterized in that: The layered headbox (204) in step 3 comprises: a bottom headbox, wherein an array of guide plates is provided at the outlet of the bottom headbox, the guide plates have a spacing of 3-8 mm, and the inclination angle is adjustable; a secondary headbox, wherein a honeycomb flow splitter and rectifying member is provided inside the secondary headbox, the honeycomb aperture is 2-4 mm, and the surface is coated with polytetrafluoroethylene to reduce fiber adhesion; The air-drying and dehydrating assembly device (304) in step three adopts a vacuum negative pressure and mechanical pressing roller coordinated dehydration method, wherein the vacuum dehydration pressure is negative 0.06-negative 0.09MPa, the dehydration time is 10-30s, the mechanical pressing roller is a silicone coated roller, the line pressure is 80-120N / cm, and the roller surface temperature is 50-80°C.

3. The wet forming process of viscose-based staple fiber felt according to claim 2, characterized in that: The multi-stage curing furnace (306) in step 4 is divided into three sections: Preheating stage: 120-140℃, humidity 30%-50%, residence time 5-8min; Main curing stage: 160-180℃, humidity ≤20%, residence time 20-25min; Cooling section: 80-100℃, humidity 40%-60%, residence time 3-5min, and the cooling section adopts circulating air cooling and spray water cooling composite cooling.

4. The wet forming process of viscose-based staple fiber felt according to claim 3, characterized in that: The preparation method of the nanocellulose reinforcing agent is as follows: wood pulp fibers are hydrolyzed with sulfuric acid and then centrifuged and purified to obtain nanocellulose with a diameter of 20-50 nm and an aspect ratio of ≥100, and the addition amount of the nanocellulose reinforcing agent is 5%-8% of the mass of the short fibers.

5. The wet forming process of viscose-based staple fiber felt according to claim 4, characterized in that: The laser slitting machine (402) in step five uses a CO2 laser with a wavelength of 10.6 μm, a power of 200-500 W, a slitting speed of 10-30 m / min, and a winding tension dynamic adjustment error of ≤1N.

6. A viscose-based staple fiber felt wet forming system for realizing the process described in any one of claims 1 to 5, characterized in that: include: A fixed frame (1), an operation panel is installed on one side of the fixed frame (1), and the operation panel includes: a DCS system and an edge computing module; a protective support plate (101) is installed on the top of the fixed frame (1); a drive motor is installed on the outside of the protective support plate (101), a transmission wheel is installed on the output end of the drive motor, and the transmission wheel is rotatably installed on the inside of the protective support plate (101); a conveyor belt (102) is installed on the inside of the protective support plate (101), wherein the conveyor belt (102) is installed on the protective support plate The protective support plate (101) is mounted on a conveying wheel on the inner side of the protective support plate (101); a flow guide cover (103) is mounted on the side end of the flow guide cover (103); an air outlet net (104) is mounted on the side end of the flow guide cover (103), wherein a plurality of air outlet holes are evenly distributed on the air outlet net (104); a flow guide carrier plate (105) is mounted on the inner bottom of the flow guide cover (103), an air inlet cover (107) is mounted on the outer bottom of the flow guide cover (103), a driving cylinder is mounted on the top of the flow guide cover (103), and a blade (107) is mounted on the output end of the driving cylinder. 06); the blade (106) is movably mounted on the guide carrier plate (105); a rotating member (108) is rotatably mounted on the inner side of the side end of the protective support plate (101); a gear is mounted on the side end of the rotating member (108) penetrating the side end of the protective support plate (101), and an air outlet groove is provided on the outer side of the rotating member (108); a servo motor is mounted on the outer side of the protective support plate (101), and a gear is mounted on the output end of the servo motor, and the gear meshes with the gear on the side end of the rotating member (108); the rotating member (1 08) are evenly distributed on the inner side thereof; a positioning tube (1010) is installed on the side end of the protective support plate (101); the inner end of the positioning tube (1010) is rotatably installed inside the rotating member (108), the positioning tube (1010) is rotatably installed on the side of the partition plate (109), and a guide groove (1011) is provided on the outer side of the positioning tube (1010); a cold air pump is installed on the outer side of the protective support plate (101), and a main flow pipe (1012) is installed on the output end of the cold air pump.

7. The viscose-based staple fiber solid felt wet forming system according to claim 6, characterized in that: The side end of the main flow pipe (1012) is connected to a flow distribution pipe (1013); the side end of the flow distribution pipe (1013) is connected to the side end of the positioning pipe (1010); a plurality of flow guide pipes (1014) are installed on the outside of the flow distribution pipe (1013); the side end of the flow guide pipe (1014) is connected to the side of the air inlet hood (107); a vacuum tube furnace (201) is installed at the bottom of the flow guide hood (103); and a vacuum tube furnace (201) is installed at the top of the fixed frame (1). An ultrasonic dispersion tank (202); the ultrasonic dispersion tank (202) is located below the output end of the vacuum tube furnace (201), an ultrasonic generator is installed in the ultrasonic dispersion tank (202), and two feed covers (203) are installed on the top of the ultrasonic dispersion tank (202); a stratified headbox (204) is installed on the top of the fixed frame (1); and the feed end of the stratified headbox (204) is connected to the discharge end of the ultrasonic dispersion tank (202).

8. The viscose-based staple fiber solid felt wet forming system according to claim 7, characterized in that: The layered headbox (204) comprises a bottom headbox, a secondary headbox and an Internet of Things sensor, and an adjustable overflow glue trough (301) is installed at the output end of the layered headbox (204); a multi-stage curing furnace (306) is installed on the side of the adjustable overflow glue trough (301), and a guide rail (302) is installed on the inner side of the adjustable overflow glue trough (301) and the multi-stage curing furnace (306); a molding plate (303) is slidably installed on the inner side of the guide rail (302); the molding plate (303) is slidably installed on the inner side of the adjustable overflow glue trough (301) and the multi-stage curing furnace (306); an air-drying and dehydrating component device (304) is installed on the upper end of the guide rail (302); the air-drying and dehydrating component device (304) comprises a vacuum negative pressure component and a mechanical pressure roller component.

9. The viscose-based staple fiber solid felt wet forming system according to claim 8, characterized in that: An Internet of Things sensor is installed on the inner side of the adjustable overflow glue tank (301), and a suction box (305) is installed on the outer side of the adjustable overflow glue tank (301); a heat transfer oil circulation pipeline (307) is installed on the inner bottom of the multi-stage curing furnace (306); a natural gas burner (308) is installed on the top of the fixed frame (1); the natural gas burner (308) is installed on one side of the multi-stage curing furnace (306); a recovery pipe (309) is installed on the top of the multi-stage curing furnace (306); a collecting pipe (3010) is installed on the side end of the recovery pipe (309); and the side end of the collecting pipe (3010) is connected to the vacuum tube furnace (201).

10. The viscose-based staple fiber solid felt wet forming system according to claim 9, characterized in that: The discharge end of the multi-stage curing furnace (306) is equipped with a cutting table (401); a molding plate (303) is slidably mounted on the cutting table (401), and a laser slitting machine (402) is mounted on the top of the cutting table (401); a reclaimed water reuse component (501) is mounted on the outer side of the adjustable overflow sizing tank (301); a black liquor recovery and treatment component (502) on the reclaimed water reuse component (501) is connected to an air-drying and dehydrating component device (304), and a return pipe (503) is mounted on the output end of the reclaimed water reuse component (501); and a side end of the return pipe (503) is mounted on a side of the ultrasonic dispersion tank (202).

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