Dry forming process and special equipment for high-temperature-resistant viscose-based pre-oxidized staple fiber felt

Abstract

The application provides a dry forming process and special equipment for high-temperature-resistant viscose-based pre-oxidized short fiber felt, relates to the technical field of felt production, and comprises the following steps: high-quality viscose short fibers are selected, and the selected viscose short fibers are placed in a nitrogen-protected pre-oxidation furnace for temperature rising treatment, and mixed gas containing NO2 is introduced for continuous temperature rising treatment; the pre-oxidized viscose short fibers are subjected to opening treatment through an opener; and a mixed solution containing a surfactant and a coupling agent is uniformly sprayed on the surface of the fibers by using a spraying device. The coupling agent can form chemical bonds between the fibers, enhance the connection strength between the fibers, improve the cohesion between the fibers and the overall strength of the felt, lay a foundation for subsequent dispersion, laying and curing, reduce the probability of uneven fiber distribution and low felt strength, and solve the problems of uneven fiber distribution and low felt strength in the process of fiber dispersion, laying and curing in the existing part of the dry forming process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of felt production, and particularly relates to a dry forming process and special equipment for high-temperature-resistant viscose-based pre-oxidized short-fiber felt. BACKGROUND

[0002] In many key industrial fields such as aerospace and high-temperature industrial furnaces, the demand for materials with both high-temperature resistance and heat insulation effect is continuously increasing. Viscose-based fibers, with their unique chemical structure and basic properties, can form a stable structure after pre-oxidation treatment, effectively resist thermal degradation and maintain shape stability in high-temperature environments. Therefore, they become an ideal raw material for preparing high-performance high-temperature-resistant felt.

[0003] However, the forming process of traditional viscose-based pre-oxidized short-fiber felt has obvious shortcomings. For example, the wet forming process not only consumes a large amount of water resources and chemical additives, but also has complicated subsequent wastewater treatment and additive residue cleaning processes, and is prone to environmental pollution. More importantly, due to the characteristics of wet processing, the high-temperature stability and mechanical properties of the finished product are weak, and it is difficult to adapt to high-end application scenarios such as aerospace and high-end high-temperature industrial furnaces. In addition, some existing dry forming processes also fail to solve the core problem. In the process of fiber dispersion, laying and curing, there are problems such as uneven fiber distribution and low felt strength. SUMMARY

[0004] The present application relates to the technical field of felt production, and particularly relates to a dry forming process and special equipment for high-temperature-resistant viscose-based pre-oxidized short-fiber felt.

[0005] In the first aspect of the present application, a dry forming process and special equipment for high-temperature-resistant viscose-based pre-oxidized short-fiber felt are provided, which specifically includes the following steps:

[0006] 1) Select high-quality viscose short fibers, and place the selected viscose short fibers in a pre-oxidation furnace under nitrogen protection for temperature rising treatment, then introduce a mixed gas containing NO2 for continuous temperature rising treatment;

[0007] 2) The pre-oxidized viscose short fibers are subjected to opening treatment by an opener;

[0008] 3) A spraying device is used to uniformly spray a mixed solution containing a surfactant and a coupling agent on the surface of the fibers;

[0009] 4) A gas flow dispersion box is used to disperse the surface-treated fibers, and the fibers are fed into the gas flow dispersion box. By adjusting the wind speed and air volume of the fan, the fibers are fully dispersed under the action of the gas flow.

[0010] 5) The fibers dispersed by the airflow enter the carding machine for carding. The carding machine adopts the roller carding method. Then, the carded fiber web is laid by the web laying machine. The number of web laying layers is adjusted according to the required thickness of the mat.

[0011] 6) The laid fiber mesh is sent to the pre-needling station of the needle punching machine for pre-needling reinforcement;

[0012] 7) The pre-needled fiber web enters the main needle punching station of the needle punching machine for main needle punching reinforcement. During the needle punching process, the needle punching parameters are adjusted according to the actual situation of the solidified felt to ensure uniform quality of the solidified felt.

[0013] 8) The needle-punched felt is sent into a hot press for hot pressing and curing;

[0014] 9) According to actual usage requirements, use the cutting equipment in the post-processing equipment to cut the hot-pressed and cured felt;

[0015] 10) The cut felt is subjected to comprehensive quality inspection by the quality inspection equipment in the post-processing equipment. Only products that pass the quality inspection can proceed to the next packaging stage.

[0016] 11) The qualified felt is sealed in plastic film using the packaging equipment in the post-processing equipment.

[0017] The system includes: a pre-oxidation furnace, an opening machine, a spraying device, an airflow dispersion box, a carding machine, a web-laying machine, a needle-punching machine, a hot press, and post-processing equipment. The opening machine is located behind the pre-oxidation furnace; the spraying device is located behind the opening machine; the airflow dispersion box is located behind the spraying device; the carding machine is located behind the airflow dispersion box; the web-laying machine is located behind the carding machine; the needle-punching machine is located behind the web-laying machine; the needle-punching machine is equipped with two sets of needle-punching mechanisms: pre-needling and main needle-punching; the hot press is located behind the needle-punching machine; and the post-processing equipment is located behind the hot press. The post-processing equipment includes cutting equipment, quality inspection equipment, and packaging equipment.

[0018] The spraying device includes: a conveyor frame located between the loosening machine and the airflow dispersion box; a lowering box located below and behind the conveyor frame; and a supporting box fixedly installed on the top front side of the conveyor frame, with the bottom of the supporting box having an inclined structure.

[0019] The spraying device further comprises: a limiting frame, which is slidingly installed on the top left side of the conveying frame, and a spring is embedded between the bottom of the limiting frame and the top of the conveying frame; a push block, which is fixedly installed on the right side of the limiting frame in a front-rear symmetrical arrangement, and the top end of the push block is in an inclined structure; a force plate, which is fixedly installed on the right side of the limiting frame at both ends; a force groove, which is formed on the outer wall of the force plate and is in an inclined structure.

[0020] The spraying device further comprises: a loosening frame, which is fixedly installed on the top right side of the conveying frame; loosening sliding blocks, which are slidingly installed on the front and rear ends of the loosening frame through springs; a conveying motor, which is fixedly installed on the right side wall of the rear loosening sliding block; conveying rollers, which are rotatably installed on the loosening sliding blocks, and the right end of the rear conveying roller is connected with the output shaft of the conveying motor; and a conveying belt, which is tensioned and installed on the two conveying rollers.

[0021] The spraying device further comprises: a spraying frame, which is fixedly installed on the top center position of the loosening frame; a resisting frame, which is slidingly installed on the inner center position of the spraying frame; resisting plates, which are fixedly installed on the front and rear sides of the resisting frame and are in an L-shaped structure; and an adjusting bolt, which is rotatably installed on the right side of the spraying frame and is connected with the right end of the resisting frame through threads.

[0022] The spraying device further comprises: a connecting pipe, which is fixedly installed on the left center position of the spraying frame and is in an inverted T-shaped structure; movable pipes, which are slidingly installed on the front and rear ends of the connecting pipe through spring sleeves, and the movable pipes are also slidingly installed on the spraying frame.

[0023] The spraying device further comprises: a driven plate, which is fixedly installed on the longitudinal section of the movable pipe, the bottom end of the driven plate is in an inclined structure, and the inclined surface of the driven plate is in contact with the inclined surface of the push block; and a module socket, which is fixedly installed on the transverse section of the movable pipe.

[0024] The spraying device further comprises: a positioning pin, which is slidingly installed in the inner part of the module socket through a spring, the inner end of the positioning pin is in a hemispherical structure, and the outer end of the positioning pin abuts against the inner side wall of the resisting plate; a module nozzle, which is insertedly installed at the bottom of the module socket; and a positioning hole, which is formed on the outer wall of the module nozzle, and the inner end of the positioning pin is insertedly installed in the inner part of the positioning hole.

[0025] The spraying device further comprises: a maintenance motor fixedly installed at the top center of the conveying frame, the maintenance motor being a double-head motor; maintenance lead screws rotatably installed at the top of the conveying frame on the left and right sides, the inner ends of the maintenance lead screws being connected with the output shafts of the maintenance motor, and the threads of the two maintenance lead screws being opposite; a synchronous frame fixedly installed at the bottom of the loosening and releasing slider, the synchronous frame being connected with the maintenance lead screws through the threads; and a synchronous column fixedly installed at the left end of the synchronous frame and sliding in the stress groove.

[0026] The application provides a dry forming process and special equipment for high-temperature-resistant viscose-based pre-oxidized short fiber felt, and has the following beneficial effects:

[0027] 1. The selected viscose short fibers are placed in a pre-oxidation furnace under nitrogen protection, heated from room temperature to 200-250 DEG C at a heating rate of 5-10 DEG C / min, and kept at this temperature for 30-60 min, and then a mixed gas containing NO2 is introduced to continue heating at a heating rate of 3-5 DEG C / min to 280-320 DEG C, and kept for 15-30 min. Through such pre-oxidation treatment, the molecular structure of the viscose fiber is rearranged and cross-linked to form pre-oxidized fibers with certain thermal stability, significantly improving the high-temperature resistance of the subsequent felt product.

[0028] 2. The mixed solution containing a surfactant and a coupling agent is uniformly sprayed on the surface of the fibers by the spraying device, so that the fibers are more easily close to each other and combine, the coupling agent can form a chemical bond between the fibers, and the connection strength between the fibers is enhanced, the cohesion between the fibers and the overall strength of the felt are improved, laying a foundation for subsequent dispersion, laying and curing, reducing the probability of uneven fiber distribution and low felt strength.

[0029] 3. The spraying device in the application can be quickly switched to a standby inspection state: only the maintenance motor needs to be started to drive the module nozzle in the device to be switched to a detachable form synchronously with the conveying belt, greatly simplifying the operation process of subsequent maintenance and component replacement, and improving the maintenance convenience. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings of the embodiments will be briefly introduced below.

[0031] The drawings described in the following description only relate to some embodiments of the application, and are not a limitation on the application.

[0032] In the drawings:

[0033] Figure 1 A schematic diagram of the overall flow module of the forming process of the application is shown;

[0034] Figure 2The overall structure of the special equipment in the forming process of the application is shown.

[0035] Figure 3 The overall structure of the spraying device of the application is shown.

[0036] Figure 4 The overall structure of the spraying device of the application is shown. Figure 3 Another perspective structure diagram is shown.

[0037] Figure 5 The overall structure of the spraying device of the application is shown.

[0038] Figure 6 The overall structure of the spraying device of the application is shown. Figure 5 The overall structure of the spraying device of the application is shown.

[0039] Figure 7 The overall structure of the spraying device of the application is shown.

[0040] Figure 8 The overall structure of the spraying device of the application is shown.

[0041] List of reference signs

[0042] 1, pre-oxidation furnace; 2, opener;

[0043] 3, spraying device; 301, conveying frame; 302, lower box; 303, upper box; 304, limiting frame; 305, push block; 306, stress plate; 307, stress groove; 308, loosening frame; 309, loosening slider; 3010, conveying motor; 3011, conveying roller; 3012, conveying belt; 3013, spraying frame; 3014, resistance frame; 3015, resistance plate; 3016, adjusting pin; 3017, connecting pipe; 3018, movable pipe; 3019, driven plate; 3020, module socket; 3021, positioning pin; 3022, module nozzle; 3023, positioning hole; 3024, maintenance motor; 3025, maintenance screw rod; 3026, synchronization frame; 3027, synchronization column;

[0044] 4, airflow dispersion box; 5, carding machine; 6, net laying machine; 7, needle punching machine; 8, hot press; 9, post-processing equipment. DETAILED DESCRIPTION

[0045] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without any inventive effort fall within the scope of protection of the present application.

[0046] Reference is made to Figures 1 to 8 Embodiment one

[0047] The present application proposes a dry forming process and special equipment for high-temperature-resistant viscose-based pre-oxidized short fiber solid felt, including the following steps:

[0048] 1) high-quality viscose short fibers are selected, the length of which is 30-80 mm and the linear density is 1.5-3.0 dtex, which can ensure good dispersibility and interweaving performance of the fibers in the subsequent processing process, laying a foundation for forming a uniform and high-strength solid felt structure, and the selected viscose short fibers are placed in a nitrogen-protected pre-oxidation furnace 1, heated from room temperature to 200-250℃ at a heating rate of 5-10℃ / min, and kept at this temperature for 30-60 min, then a mixed gas containing NO2 (the volume fraction of NO2 is 2%-5%, and the rest is nitrogen) is introduced, and the temperature is further increased to 280-320℃ at a heating rate of 3-5℃ / min, and kept for 15-30 min;

[0049] 2) the pre-oxidized viscose short fibers are subjected to opening treatment by an opener 2, the roller speed of the opener 2 is controlled at 300-500 r / min, the opening process can scatter the fiber bundles and preliminarily separate them, providing a good foundation for subsequent dispersion and carding, and ensuring uniform distribution of the fibers in the subsequent processing;

[0050] 3) in order to improve the cohesion between the fibers and the overall strength of the solid felt, the opened fibers are subjected to surface treatment, a mixed solution containing a surfactant and a coupling agent is uniformly sprayed on the surface of the fibers by a spraying device 3, the mass fraction of the surfactant in the mixed solution is 0.5%-1.5%, and the mass fraction of the coupling agent is 1%-3%, the surfactant can reduce the surface energy of the fiber surface, making the fibers more easily approach and combine with each other, and the coupling agent can form a chemical bond between the fibers, enhancing the connection strength between the fibers;

[0051] 4), the surface treated fibers are dispersed by the airflow dispersion box 4, the fibers are sent into the airflow dispersion box 4, the air speed and air volume of the fan are adjusted, the fibers are fully dispersed under the action of the airflow, the air speed is controlled at 15-25 m / s, the air volume is adjusted according to the feeding amount of the fibers, the fibers can be uniformly suspended in the airflow, the airflow dispersion can effectively avoid the damage of the fibers in the dispersion process, and the uniform distribution of the fibers is ensured;

[0052] 5), the fibers dispersed by the airflow are combed in the carding machine 5, the carding machine 5 adopts a roller carding mode, the rotating speed of the roller is 150-250 r / min, the carding process can further comb the fibers, make the fibers more orderly arranged, and form a uniform fiber web, then the combed fiber web is laid by the laying machine 6, the laying speed is 2-5 m / min, the laying layers are adjusted according to the thickness of the required felt, generally 3-8 layers, through multi-layer laying, the thickness and strength of the felt can be increased, and the distribution of the fibers in different directions is more uniform;

[0053] 6), the laid fiber web is sent to the pre-needling machine station of the needle punching machine 7 for pre-needling reinforcement, the pre-needling frequency of the pre-needling mechanism is 400-600 times / min, the needle punching depth is 10-15 mm, the pre-needling can preliminarily intertwine the fibers in the fiber web, form a certain strength, and facilitate the subsequent main needle punching process;

[0054] 7), the fiber web after pre-needling is sent to the main needle punching station of the needle punching machine 7 for main needle punching reinforcement, the needle punching frequency of the main needle punching mechanism is 600-800 times / min, the needle punching depth is 8-12 mm, the main needle punching process further increases the intertwining between the fibers, improves the strength and density of the felt, and the needle punching parameters are adjusted according to the actual situation of the felt during the needle punching process, to ensure the uniform quality of the felt;

[0055] 8), the felt after needle punching is sent to the hot press 8 for hot pressing and curing, the hot pressing temperature is controlled at 180-220℃, the hot pressing pressure is 2-5 Mpa, under this temperature and pressure, the coupling agent on the surface of the fibers and the residual surfactant further react, the bonding force between the fibers is enhanced, the fiber web is more closely combined together, the overall strength and stability of the felt are improved, the hot pressing time is adjusted according to the thickness and material of the felt, generally 10-30 min, to ensure that the fibers can be fully cured to form a stable structure in sufficient time;

[0056] 9), according to the actual use requirement, the felt after hot pressing and curing is cut by the cutting equipment in the post-processing equipment 9, the cutting size precision is controlled within ±1 mm, to ensure that the size of the felt meets the requirements;

[0057] 10) The cut solid felt is subjected to comprehensive quality inspection by the quality inspection equipment in the post-processing equipment 9, including appearance inspection (whether there are holes, edge defects, etc.), thickness inspection (thickness deviation is controlled within ±0.5mm), strength inspection (tensile strength is not less than 10MPa, tear strength is not less than 5N / mm) and high temperature resistance performance inspection (maintained at 800℃ for 1h, the solid felt structure has no obvious change), only the products passing the quality inspection can enter the next packaging link;

[0058] 11) The solid felt passing the inspection is sealed and packaged by the packaging equipment in the post-processing equipment 9, to prevent pollution and damage in the process of transportation and storage.

[0059] It comprises a pre-oxidation furnace 1, an opener 2, a spraying device 3, an airflow dispersion box 4, a carding machine 5, a laying machine 6, a needle punching machine 7, a hot press 8 and a post-processing equipment 9, the opener 2 is arranged behind the pre-oxidation furnace 1; the spraying device 3 is arranged behind the opener 2; the airflow dispersion box 4 is arranged behind the spraying device 3; the carding machine 5 is arranged behind the airflow dispersion box 4; the laying machine 6 is arranged behind the carding machine 5; the needle punching machine 7 is arranged behind the laying machine 6; the needle punching machine 7 is equipped with two sets of needle punching mechanisms of pre-needling and main needling; the hot press 8 is arranged behind the needle punching machine 7; the post-processing equipment 9 is arranged behind the hot press 8; the post-processing equipment 9 comprises a cutting device, a quality inspection device and a packaging device.

[0060] The spraying device 3 comprises: a conveying frame 301 located between the opener 2 and the airflow dispersion box 4; an enabling and lowering box 302 located at the lower rear side of the conveying frame 301; an upper receiving box 303 fixedly installed at the top front side of the conveying frame 301, and the bottom of the upper receiving box 303 is of an inclined structure; a limiting frame 304 slidingly installed at the top left side of the conveying frame 301, and a spring is embedded between the bottom of the limiting frame 304 and the top of the conveying frame 301; top pushing blocks 305 symmetrically arranged and fixedly installed at the right side of the limiting frame 304, and the top end of the top pushing block 305 is of an inclined structure; force receiving plates 306 fixedly installed at the right side of the limiting frame 304; force receiving grooves 307 formed in the outer wall of the force receiving plate 306, and the force receiving groove 307 is of an inclined structure; a loosening frame 308 fixedly installed at the top right side of the conveying frame 301; loosening sliding blocks 309 slidingly installed at the front and rear ends of the loosening frame 308 through springs; a conveying motor 3010 fixedly installed at the right side wall of the rear loosening sliding block 309; conveying rollers 3011 rotatingly installed on the loosening sliding block 309, and the right end of the rear conveying roller 3011 is connected with the output shaft of the conveying motor 3010; a conveying belt 3012 tensioningly installed on the two conveying rollers 3011; a spraying frame 3013 fixedly installed at the top middle position of the loosening frame 308; a resisting frame 3014 slidingly installed at the middle position inside the spraying frame 3013; resisting plates 3015 fixedly installed at the front and rear sides of the resisting frame 3014, and the resisting plate 3015 is of an L-shaped structure; an adjusting bolt 3016 rotatingly installed at the right side of the spraying frame 3013, and the adjusting bolt 3016 is connected with the right end of the resisting frame 3014 through threads; a connecting pipe 3017 fixedly installed at the left middle position of the spraying frame 3013, and the connecting pipe 3017 is of an inverted T-shaped structure; a movable pipe 3018 slidingly installed at the front and rear ends of the connecting pipe 3017 through a spring sleeve, and the movable pipe 3018 is also slidingly installed on the spraying frame 3013; a driven plate 3019 fixedly installed on the longitudinal section of the movable pipe 3018, the bottom end of the driven plate 3019 is of an inclined structure, and the inclined surface of the driven plate 3019 is in contact with the inclined surface of the top pushing block 305; a module socket 3020 fixedly installed on the transverse section of the movable pipe 3018; a positioning pin 3021 slidingly installed inside the module socket 3020 through a spring, the inner end of the positioning pin 3021 is of a hemispherical structure, and the outer end of the positioning pin 3021 abuts against the inner side wall of the resisting plate 3015; and a module nozzle 3022 insertedly installed at the bottom of the module socket 3020.Positioning hole 3023, positioning hole 3023 is opened on the outer wall of module shower nozzle 3022, and the inner end of positioning pin 3021 is inserted into the inside of positioning hole 3023;Maintenance motor 3024, maintenance motor 3024 is fixedly installed at the top of conveying frame 301 in the middle position, maintenance motor 3024 is a double head motor;Maintenance lead screw 3025, maintenance lead screw 3025 is rotatably installed at the top of conveying frame 301 on the front and back sides, the inner end of maintenance lead screw 3025 is connected with the output shaft of maintenance motor 3024, and the threads of the two maintenance lead screws 3025 are opposite;Synchronous frame 3026, synchronous frame 3026 is fixedly installed at the bottom of the release sliding block 309, and the synchronous frame 3026 is connected with the maintenance lead screw 3025 through the thread;Synchronous column 3027, synchronous column 3027 is fixedly installed at the left end of synchronous frame 3026, and synchronous column 3027 slides in the inside of stress groove 307.

[0061] In example two, on the basis of example one, viscose staple fibers with a length of 40 mm and a linear density of 2.0 dtex are selected, which are placed in a pre-oxidation furnace 1 under nitrogen protection, heated from room temperature to 220℃ at a heating rate of 6℃ / min, and kept for 40 min; then a mixed gas containing 3% NO2 by volume is introduced, and heated to 300℃ at a heating rate of 4℃ / min, and kept for 20 min; then the pre-oxidized fibers are opened by an opener 2 at a roller speed of 400 r / min; then a mixed solution containing 1% surfactant and 2% coupling agent is sprayed on the surface of the fibers by a spraying device 3; then the fibers are sent into an air flow dispersion box 4, with a wind speed of 20 m / s and a wind volume adjusted according to the fiber feeding amount; the air flow dispersed fibers enter a carding machine 5 at a roller speed of 200 r / min; the carded fiber web is laid by a laying machine 6 at a laying speed of 3 m / min and with 5 layers; then the fiber web is pre-needled by a needle punching machine 7 at a needle frequency of 500 times / min and a needle depth of 12 mm; then the fiber web is main-needled by the needle punching machine 7 at a needle frequency of 700 times / min and a needle depth of 10 mm; after needle punching, the felt is sent into a hot press 8 at a hot pressing temperature of 200℃, a hot pressing pressure of 3 MPa, and a hot pressing time of 20 min; then the felt is cut by a cutting device in a post-processing equipment 9; then the felt quality is detected by a quality detection device in the post-processing equipment 9 and packaged after passing the quality detection; it is detected that the felt product has uniform thickness, a tensile strength of 12 MPa, and a tear strength of 6 N / mm, and the structure has no obvious change after being kept at 800℃ for 1 h, meeting the requirements of high-performance and high-temperature-resistant felt.

[0062] Example 3, on the basis of example 1, the length of 60 mm, linear density of 2.5 dtex viscose staple fiber, under nitrogen protection, with 8 ℃ / min heating rate from room temperature to 240 ℃, keep 50 min, into the mixed gas of NO2 volume fraction of 4%, with 3 ℃ / min heating rate to 310 ℃, keep 25 min; open machine 2 roller speed of 450 r / min, in the surface treatment, the mass fraction of surfactant in the mixed solution is 1.2%, the mass fraction of coupling agent is 2.5%; air dispersion wind speed 22 m / s, carding machine 5 roller speed 220 r / min, laying speed 4 m / min, laying layer 6 layers; pre-needling frequency 550 times / min, depth 13 mm; main needle frequency 750 times / min, depth 11 mm; hot pressing temperature 210 ℃, pressure 4 MPa, time 25 min; cutting, detection by post-processing equipment 9, the felt product has excellent performance, thickness deviation is within ±0.3 mm, tensile strength is 13 MPa, tear strength is 7 N / mm, high temperature performance is good, in line with product quality standards.

[0063] The principle of the spraying process: through the connection pipe 3017, the liquid supply device is connected to the inside of the connection pipe 3017 and the movable pipe 3018, and the mixed solution containing the surfactant and the coupling agent is transported to the inside of the connection pipe 3017 and the movable pipe 3018. In this process, the upper box 303 collects the fibers treated by the opener 2, and the fibers collected are guided to the conveying belt 3012 by the action of the inclined structure at the bottom end of the inside of the upper box 303. At this time, the conveying motor 3010 rotates with the rear conveying roller 3011, and the conveying roller 3011 cooperates with the other conveying roller 3011 to drive the conveying belt 3012 to run, so that the conveying belt 3012 transports the fibers to the inside of the spraying frame 3013. In the conveying process, the module nozzle 3022 atomizes and releases the mixed solution in the inside of the movable pipe 3018, so that the mixed solution is uniformly sprayed on the fibers. The sprayed fibers are guided into the inside of the upper and lower boxes 302, and the fibers are temporarily stored for easy transfer to the fiber dispersion process. Thus, the spraying process of the fibers is completed. When the module nozzle 3022 needs to be disassembled, the module nozzle 3022 can be disassembled from the module socket 3020 by manually rotating the adjusting bolt 3016, controlling the descent of the resistance frame 3014 and the resistance plate 3015, and making the position of the resistance plate 3015 staggered with the positioning pin 3021. At this time, the module nozzle 3022 can be disassembled from the module socket 3020 by slightly applying force. Compared with the conventional threaded locking nozzle, the nozzle in the device is more convenient to disassemble and replace, and is suitable for disassembling and replacing a large number of nozzles. At the same time, the spraying device 3 also has a standby state. Only the maintenance motor 3024 needs to be started to control the rotation of the maintenance lead screw 3025, so that the maintenance lead screw 3025 moves inward with the two synchronous frames 3026, the two loosening sliding blocks 309, and the two conveying rollers 3011 by utilizing the opposite characteristics of the thread teeth. The two conveying rollers 3011 cancel the tensioning of the conveying belt 3012 by moving inward. In the process of moving inward of the synchronous frame 3026, the synchronous column 3027 also converts the inward moving force into downward pressure by utilizing the inclined characteristics of the stress groove 307 to provide the downward pressure to the stress plate 306 and the limiting frame 304, so that the limiting frame 304 cancels the resistance to the left disassembly path of the conveying belt 3012 by descending, thereby facilitating the disassembly of the conveying belt 3012 in a loosened state. At the same time, the top pushing block 305 also descends with the descending of the limiting frame 304, so that it cancels the pushing of the driven plate 3019. At this time, the movable pipe 3018 moves outward with the module nozzle 3022 under the action of the spring, so that the module nozzle 3022 is staggered with the resistance plate 3015, and the resistance plate 3015 no longer resists the outward moving path of the positioning pin 3021. In this way, the module nozzle 3022 and the conveying belt 3012 in the spraying device 3 are in a state of easy disassembly, which is convenient for maintenance and replacement.

[0064] In this paper, the following points need to be noted:

[0065] 1. The drawings of the embodiments of the present application only relate to the structures involved in the embodiments of the present application, and other structures can be referred to the general design.

[0066] 2. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0067] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. Dry forming process of high temperature resistant viscose-based pre-oxidized staple fiber batt, characterized in that, It comprises the following steps: 1) first, select high-quality viscose staple fibers, and place the selected viscose staple fibers in a nitrogen-protected pre-oxidation furnace (1) for temperature treatment, then, a mixed gas containing NO2 is introduced, and the temperature treatment is continued; 2) the pre-oxidized viscose staple fibers are opened by an opener (2); 3) a spray device (3) is used to uniformly spray a mixed solution containing a surfactant and a coupling agent on the surface of the fibers; 4) an air flow dispersion box (4) is used to disperse the surface-treated fibers, the fibers are fed into the air flow dispersion box (4), and the air speed and air volume of the fan are adjusted to make the fibers fully dispersed under the action of air flow; 5) the air flow dispersed fibers enter a carding machine (5) for carding, the carding machine (5) uses a roller carding method, then a laying machine (6) is used to lay the carded fiber web, and the number of layers is adjusted according to the thickness of the required felt; 6) the laid fiber web is sent to the pre-needling station of the needle punching machine (7) for pre-needling reinforcement; 7) the pre-needled fiber web enters the main needle punching station of the needle punching machine (7) for main needle punching reinforcement, and the needle punching parameters are adjusted according to the actual situation of the felt to ensure the uniform quality of the felt; 8) the needle punched felt is sent to a hot press (8) for hot pressing and curing; 9) according to the actual use requirement, a cutting device in the post-processing equipment (9) is used to cut the hot pressed and cured felt; 10) a quality inspection device in the post-processing equipment (9) is used to comprehensively inspect the quality of the cut felt, and only the products that pass the quality inspection can enter the next packaging link; 11) a packaging device in the post-processing equipment (9) is used to seal and package the qualified felt with a plastic film.

2. Specialized equipment for implementing the dry forming process of high temperature resistant viscose-based pre-oxidized staple fiber felt according to claim 1, characterized in that, It comprises: a pre-oxidation furnace (1), an opener (2), a spray device (3), an air flow dispersion box (4), a carding machine (5), a laying machine (6), a needle punching machine (7), a hot press (8), and a post-processing equipment (9), the rear of the pre-oxidation furnace (1) is provided with the opener (2); the rear of the opener (2) is provided with the spray device (3); the rear of the spray device (3) is provided with the air flow dispersion box (4); the rear of the air flow dispersion box (4) is provided with the carding machine (5); the rear of the carding machine (5) is provided with the laying machine (6); the rear of the laying machine (6) is provided with the needle punching machine (7); the needle punching machine (7) is equipped with two sets of needle punching mechanisms for pre-needling and main needle punching; the rear of the needle punching machine (7) is provided with the hot press (8); the rear of the hot press (8) is provided with the post-processing equipment (9); the post-processing equipment (9) comprises a cutting device, a quality inspection device, and a packaging device.

3. The special equipment for dry process forming of high temperature resistant viscose based pre-oxidized staple fiber felt according to claim 2, characterized in that, The spraying device (3) comprises: a conveying frame (301) located between the opener (2) and the airflow dispersion box (4); a lifting-off box (302) located at the lower rear side of the conveying frame (301); and a bearing-up box (303) fixedly installed at the top front side of the conveying frame (301), wherein the bottom of the bearing-up box (303) is in an inclined structure.

4. The special equipment for dry process forming of high temperature resistant viscose based pre-oxidized staple fiber felt according to claim 3, characterized in that, The spraying device (3) further comprises: a limiting frame (304) slidably installed at the top left side of the conveying frame (301), wherein a spring is embedded between the bottom of the limiting frame (304) and the top of the conveying frame (301); top pushing blocks (305) fixedly installed at the right side of the limiting frame (304) in a front-rear symmetrical arrangement, wherein the top end of the top pushing block (305) is in an inclined structure; force receiving plates (306) fixedly installed at the right side of the limiting frame (304) at the front and rear ends; and force receiving grooves (307) formed on the outer wall of the force receiving plate (306) in an inclined structure.

5. The special equipment for dry process forming of high temperature resistant viscose based pre-oxidized staple fiber felt according to claim 4, characterized in that, The spraying device (3) further comprises: a loosening frame (308) fixedly installed at the top right side of the conveying frame (301); loosening sliding blocks (309) slidably installed at the front and rear ends of the loosening frame (308) through springs; a conveying motor (3010) fixedly installed at the right side wall of the rear loosening sliding block (309); conveying rollers (3011) rotatably installed on the loosening sliding block (309), wherein the right end of the rear conveying roller (3011) is connected with the output shaft of the conveying motor (3010); and a conveying belt (3012) tightly installed on the two conveying rollers (3011).

6. The special equipment for dry forming process of high temperature resistant viscose based pre-oxidized staple fiber felt according to claim 5, characterized in that, The spraying device (3) further comprises: a spraying frame (3013) fixedly installed at the top center position of the loosening frame (308); a resisting frame (3014) slidably installed at the center position inside the spraying frame (3013); resisting plates (3015) fixedly installed at the front and rear sides of the resisting frame (3014) in an L-shaped structure; an adjusting bolt (3016) rotatably installed at the right side of the spraying frame (3013), wherein the adjusting bolt (3016) is connected with the right end of the resisting frame (3014) through threads.

7. The special equipment for dry forming process of high temperature resistant viscose based pre-oxidized staple fiber mat according to claim 6, characterized in that, The spraying device (3) further comprises: a connecting pipe (3017) fixedly installed at the left center position of the spraying frame (3013) in an inverted T-shaped structure; and a movable pipe (3018) slidably installed at the front and rear ends of the connecting pipe (3017) through a spring sleeve, wherein the movable pipe (3018) is also slidably installed on the spraying frame (3013).

8. The special equipment for dry forming process of high temperature resistant viscose based pre-oxidized staple fiber felt according to claim 7, characterized in that, The spray device (3) further comprises a driven plate (3019) fixedly installed on the longitudinal section of the movable pipe (3018), the bottom end of the driven plate (3019) is of an inclined structure, and the inclined surface of the driven plate (3019) is in contact with the inclined surface of the push block (305); and a module socket (3020) fixedly installed on the transverse section of the movable pipe (3018).

9. The special equipment for dry forming process of high temperature resistant viscose based pre-oxidized staple fiber mat according to claim 8, characterized in that, The spray device (3) further comprises a positioning pin (3021) slidably installed in the interior of the module socket (3020) through a spring, the inner end of the positioning pin (3021) is of a hemispherical structure, the outer end of the positioning pin (3021) abuts against the inner side wall of the resisting plate (3015), a module nozzle (3022) inserted into the bottom of the module socket (3020), and a positioning hole (3023) formed in the outer wall of the module nozzle (3022), and the inner end of the positioning pin (3021) is inserted into the interior of the positioning hole (3023).

10. The special equipment for dry forming process of high temperature resistant viscose based pre-oxidized staple fiber mat according to claim 9, characterized in that, The spray device (3) further comprises an inspection motor (3024) fixedly installed at the top center position of the conveying frame (301), the inspection motor (3024) is a double-head motor, an inspection lead screw (3025) rotatably installed at the top front and back sides of the conveying frame (301), the inner end of the inspection lead screw (3025) is connected with the output shaft of the inspection motor (3024), the threads of the two inspection lead screws (3025) are opposite, a synchronous frame (3026) fixedly installed at the bottom of the loosening sliding block (309), the synchronous frame (3026) is connected with the inspection lead screw (3025) through threads, and a synchronous column (3027) fixedly installed at the left end of the synchronous frame (3026), and the synchronous column (3027) slides in the interior of the stress groove (307).

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