Method and equipment for preparing nano-fiber sound-absorbing cotton in mid-bass frequency band

Abstract

The invention relates to the technical field of sound-absorbing cotton preparation, in particular to a method and equipment for preparing mid-bass frequency band nanofiber sound-absorbing cotton. The equipment comprises a base, two symmetrically-arranged side plates are fixedly installed on one side of the base through a long plate, and two heat sealing rollers which are arranged up and down are jointly and rotationally installed between the two side plates; according to the sound-absorbing cotton heat sealing device, through opening of the upper heat sealing roller and the lower heat sealing roller, sound-absorbing cotton passing through the lower portion and non-woven fabric on the surface of the sound-absorbing cotton can be subjected to heat sealing treatment, the sound-absorbing cotton can also be pushed, and the sound-absorbing cotton can be conveyed through the two heat sealing rollers; water in the wiping sponge uniformly smears and wets the surface of the heat-sealing roller, so that the temperature of the surface of the heat-sealing roller is reduced, and on one hand, the situation that the sound-absorbing cotton is damaged due to the fact that the temperature is too high when the heat-sealing roller conducts heat sealing on the sound-absorbing cotton can be avoided; and on the other hand, fibers on the surface can be adhered when the wet surface of the heat sealing roller is in contact with the sound-absorbing cotton.

Description

Technical Field

[0001] The invention relates to the technical field of sound-absorbing cotton preparation, and specifically to a method and equipment for preparing nanofiber sound-absorbing cotton in a medium and low frequency band. Background Art

[0002] Sound-absorbing cotton is a man-made inorganic fiber material. So far, porous fibers and foaming materials such as PP, PET, polyurethane and glass fiber are the most representative and widely used sound-absorbing materials we know. Since most of the above materials are at the micron level, there are few application scenarios for nano-level fibers below 1 micron, so the application effect and sound absorption and sound insulation capabilities are also greatly limited. The size, complexity and distance between holes in the porous structure of the sound-absorbing material are very important indicators. Therefore, in order to absorb sound waves of various frequency bands, it has been proven to be a very effective method to use coarse fibers of several microns as the skeleton to maintain the overall elasticity, and to use nano-level ultra-fine fibers to fill the porous structure to increase the surface area and complexity of the material.

[0003] The prior art discloses a Chinese patent with application number CN202210967975.6, a molding equipment for the production of automotive sound-absorbing cotton, and discloses that when the square tube is located at the bottom, the distance between the slider and the horizontal axis is the largest. At this time, the spring is in a stretched state. Under the action of the tension, the slider will drive the clamping assembly to clamp the sound-absorbing cotton belt on the square tube. In this way, the sound-absorbing cotton belt can be prevented from being offset during the punching process, thereby ensuring the accuracy of the punching process.

[0004] The above device can punch out the sound-absorbing cotton during production. However, since residual fibers are adhered to the surface of the sound-absorbing cotton after production, the surface needs to be cleaned. At the same time, the above device can only cut the sound-absorbing cotton individually and cannot cut it continuously. Summary of the invention

[0005] The object of the present invention is to provide a method and equipment for preparing nanofiber sound-absorbing cotton in the mid- and low-frequency bands, so as to solve the problems raised in the above-mentioned background technology.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A preparation device for nanofiber sound-absorbing cotton in the medium and low frequency bands, comprising a base, two symmetrically arranged side plates are fixedly installed on one side of the base through a long plate, two heat-sealing rollers are installed between the two side plates and are rotatably arranged in an upper and lower direction, a receiving frame connected to the side plate is provided on the side away from the two heat-sealing rollers, the upper receiving frame and the side plate are slidably connected, a wiping sponge in contact with the heat-sealing roller is provided in the receiving frame, a placing frame is fixedly installed on one side of the two hot plates, two circular holes arranged in an upper and lower direction are symmetrically provided on the two placing frames, cleaning buckets are fixedly installed in the circular holes, cleaning ports are horizontally provided on the sides of the two cleaning buckets that are close to each other, a positioning frame is fixedly installed on the other side of the base, a plurality of cutting components are provided on the positioning frame, a supporting frame fixedly connected to the base is provided below the positioning frame, a plurality of guide components connected to the cutting components are slidably installed on the supporting frame.

[0008] Furthermore, telescopic tubes connected to the inner cavity of the upper storage rack are fixedly installed at equal intervals on the upper end surface of the upper storage rack, and a water tank is fixedly installed on one end of the multiple telescopic tubes away from the upper storage rack, the water tank is connected to the inner cavity of the telescopic tube, a plug fixedly connected to the wiping sponge is provided in the telescopic tube, the upper part of the plug is made of rubber, L-shaped fixing blocks are fixedly installed on both sides of the lower end surface of the water tank, the fixing block is fixedly connected to the top of the side plate away from the water tank, a rectangular groove is opened in the middle of the fixing block, a connecting plate fixedly connected to the storage rack is slidably installed in the rectangular groove, and a spring is commonly installed between the connecting plate and the fixing block.

[0009] Furthermore, a center wheel is installed in the middle of the side plate on one side through rotation by a motor, and side wheels rotatably connected to the side plate are provided on the upper and lower sides of the center wheel, and the upper and lower side wheels are fixedly connected to the upper and lower heat-sealing rollers respectively, and a cam is fixedly installed on the side of the center wheel away from the side plate, and a push-pull plate is rotatably installed on one side of the cam through a round rod, and a fixed frame fixedly connected to the side plate is provided below the push-pull plate, a compression box is fixedly installed in the middle of the fixed frame, and a compression rod is slidably installed in the compression box, and one end of the compression rod is located inside the compression box as a piston, and the push-pull plate slides in the compression rod at one end away from the cam.

[0010] Furthermore, an air transfer box is fixedly installed on one side of the compression box, and connecting pipes are connected to the upper and lower parts of the air transfer box. The end of the connecting pipe away from the air transfer box is connected to a blowing plate fixed to the side panel, and a blowing port is provided on the side of the blowing plate close to the heat sealing roller.

[0011] Furthermore, an outer tube connected to the inner cavity of the telescopic tube is fixedly installed at one end of the telescopic tube, a side box is fixedly installed between the multiple outer tubes, and water pipes connected to the inner cavity are fixedly installed on both sides of the side box. The end of the water pipe away from the side box supplies water to the sponge in the lower side storage rack.

[0012] Furthermore, a collecting bin is rotatably mounted on one side of the cleaning barrel, a material discharge port is provided at the lower part of the collecting bin, a dust suction groove is circumferentially provided on one side of the collecting bin close to the cleaning barrel, and a fan is provided in the middle of the collecting bin.

[0013] Furthermore, a dovetail groove is horizontally opened in the middle of the positioning frame, and multiple movable plates are slidably installed in the dovetail groove. The front side of the movable plate is fixedly connected to the cutting assembly, and a circular shaft is fixedly installed on the upper part of the movable plate. Shaped frames are fixedly installed on both sides of the positioning frame. A threaded rod is installed in the middle of the shaped frame through rotation of a motor, and a connecting piece is threadedly installed on the threaded rod. A lifting plate is fixedly installed between the connecting pieces on both sides, and the lifting plate is provided with adjustment grooves for sleeved the circular shafts respectively.

[0014] Furthermore, the cutting assembly includes a mounting frame, a cutting knife is rotatably installed in the middle of the mounting frame through a rotating shaft, an adjusting wheel is fixedly installed at one end of the rotating shaft, an electric push rod fixedly connected to the mounting frame is provided above the adjusting wheel, a toothed plate meshing with the adjusting wheel is fixedly installed at the telescopic end of the electric push rod, a connecting plate fixedly connected to the mounting frame is horizontally provided above the cutting knife, a pressing frame sleeved on the outside of the rotating shaft is provided on the outside of the cutting knife, and a spring is commonly connected between the connecting plate and the pressing frame.

[0015] Furthermore, the guide assembly includes a moving bar slidably connected to the supporting frame, a rectangular cavity is opened in the moving bar, a plurality of springs are fixedly installed in the rectangular cavity, and a guide groove plate located on the supporting frame is commonly installed at one end of the plurality of springs away from the rectangular cavity.

[0016] Another object of the present invention is to provide a method for preparing nanofiber sound-absorbing cotton in the mid- and low-frequency bands, comprising the following steps:

[0017] S1: Sound-absorbing cotton flash steaming:

[0018] The high molecular organic material is melted, and the blown fibers are intertwined with each other by flash evaporation, and then the non-woven fabric is compounded on both sides of the primary sound-absorbing cotton to form a sound-absorbing cotton product;

[0019] S2: Pressing and cleaning of sound-absorbing cotton:

[0020] The sound-absorbing cotton is heat-pressed by rotating the two heat-sealing rollers relative to each other, so that the non-woven fabric on its surface and the sound-absorbing cotton are pressed together, and the sound-absorbing cotton can be pushed when the two heat-sealing rollers rotate relative to each other, and the heat-sealing rollers can clean the excess fiber impurities on the surface of the sound-absorbing cotton when they are in contact with each other;

[0021] S3: Cutting of sound-absorbing cotton:

[0022] The pressed and cleaned sound-absorbing cotton can be cut into multiple pieces by the setting of multiple cutting knives when passing through the cutting assembly, and the spacing between the multiple cutting knives can be adjusted by lifting and lowering the lifting plate to meet the cutting width of different requirements of the sound-absorbing cotton.

[0023] Beneficial effects of the present invention:

[0024] 1. The present invention can heat-seal the sound-absorbing cotton passing below and the non-woven fabric on its surface by opening the upper and lower heat-sealing rollers, and can also push the sound-absorbing cotton by rotating the two heat-sealing rollers. At the same time, when the heat-sealing rollers rotate, they contact with the wiping sponge, so that the water in the wiping sponge is evenly smeared and moistened on the surface of the heat-sealing roller, thereby reducing the temperature of the surface of the heat-sealing roller. On the one hand, it can avoid the situation that the sound-absorbing cotton is damaged due to the excessive temperature of the heat-sealing roller when heat-sealing the sound-absorbing cotton. On the other hand, it can also make the fibers on the surface of the sound-absorbing cotton adhere when the moistened surface of the heat-sealing roller contacts with the sound-absorbing cotton.

[0025] 2. The present invention realizes that the moisture content of the wiping sponge decreases after being used for a certain period of time, and the weight of the wiping sponge and the upper storage rack becomes lighter. Therefore, the upper storage rack is lifted upward under the action of the spring. When the upper storage rack moves upward, the connecting plate slides upward in the rectangular groove opened in the middle of the fixed block. At this time, the upper storage rack compresses the telescopic tube. At the same time, the plug moves upward synchronously with the upward movement of the storage rack, thereby eliminating the blockage of the connection between the telescopic tube and the water tank. At this time, the water in the water tank is used to inject water into the wiping sponge in the upper storage rack through the telescopic tube. When the water flows into the telescopic tube, due to the setting of the outer tube, the water in the telescopic tube is also retained in the side box. Finally, the water in the side box is injected into the wiping sponge in the lower storage rack through the water pipes on both sides to moisten the wiping sponge.

[0026] 3. The present invention drives the center wheel to rotate by turning on the motor. When the center wheel rotates, it drives the upper and lower side wheels to rotate towards each other through meshing synchronization. When the two side wheels rotate towards each other, the two heat-sealing rollers rotate synchronously. During the rotation, on the one hand, the upper and lower surfaces of the sound-absorbing cotton can be heat-sealed synchronously, and on the other hand, the sound-absorbing cotton can be transported.

[0027] 4. When the center wheel of the present invention rotates, it can also drive the cam to rotate. When the cam rotates, it drives the push-pull plate to rotate, so that the push-pull plate reciprocates and compresses the compression rod when it rotates. When the compression rod reciprocates and compresses in the compression box, the gas in the compression box is transmitted to the blowing plate through the connecting pipe, and finally blown out through the blowing port on the blowing plate. Through the setting of the blowing plate, the upper and lower heat-sealing rollers can be cooled when heat-sealing the sound-absorbing cotton, and on the other hand, the fibers on the sound-absorbing cotton can be blown off and cleaned.

[0028] 5. The present invention can cut the pushed sound-absorbing cotton through the setting of the cutting knife, and the setting of the spring and the pressing frame outside the cutting knife can enable the pressing frame to press the surface of the sound-absorbing cotton to avoid deviation and damage during cutting due to the soft material of the sound-absorbing cotton itself, and the setting of the guide groove plate can guide and support the cutting knife when cutting the sound-absorbing cotton. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 It is a schematic diagram of the inner structure of the base of the present invention;

[0032] Figure 3 It is a schematic diagram of the layout structure on the side panel of the present invention;

[0033] Figure 4 It is a schematic cross-sectional view of the layout structure on the side panel of the present invention;

[0034] Figure 5 It is a schematic diagram of the side cross-sectional structure between the water tank and the heat sealing roller of the present invention;

[0035] Figure 6 It is a schematic diagram of the structure between the placement rack and the cleaning bucket of the present invention;

[0036] Figure 7 It is a schematic diagram of the side section structure of the support frame of the present invention;

[0037] Figure 8 It is a schematic diagram of the structure between the positioning frame and the cutting assembly of the present invention;

[0038] Fig. 9 It is a schematic diagram of the structure of the cutting assembly of the present invention;

[0039] Fig.10 The sound-absorbing cotton of the present invention is a schematic diagram of the structure in a tire;

[0040] Fig.11 This is a schematic diagram of the principle of sound wave absorption by the fiber assembly in the sound-absorbing cotton of the present invention;

[0041] Fig.12 is a schematic diagram of the fibers in the sound-absorbing cotton of the present invention;

[0042] Fig.13 It is a schematic diagram of the sound insulation ability of the fibers in the sound-absorbing cotton of the present invention to 0-500HZ;

[0043] Fig.14 This is a schematic diagram of an example of the sound-absorbing cotton of the present invention being applied in a wall;

[0044] Fig.15 It is a schematic diagram of the sound absorption and sound insulation of the fibers in the sound-absorbing cotton in the sound insulation board;

[0045] Fig.16 It is a data diagram of some sound absorption coefficients between 100 and 5000 in the sound-absorbing cotton of the present invention;

[0046] Fig.17 It is a diagrammatic representation of the sound absorption coefficient of part of the sound-absorbing cotton of the present invention between 100 and 5000.

[0047] The reference numerals in the figures are as follows:

[0048] 1. Base; 2. Side plate; 21. Center wheel; 22. Side wheel; 220. Heat sealing roller; 23. Storage rack; 230. Wiping sponge; 231. Telescopic tube; 232. Plug; 233. Outer tube; 234. Side box; 235. Water pipe; 24. Water tank; 240. Fixed block; 241. Connecting plate; 25. Fixed rack; 251. Compression box; 252. Compression rod; 253. Cam; 254. Push-pull plate; 255. Air box; 256. Connecting tube; 257. Blowing plate; 26. Placement rack; 261. Cleaning Clean bucket; 262, collection bin; 263, discharge port; 264, fan; 265, dust suction groove; 31, positioning frame; 32, dovetail groove; 33, moving plate; 330, round shaft; 34, profile frame; 340, threaded rod; 341, connector; 342, lifting plate; 343, regulating groove; 35, mounting frame; 351, connecting plate; 36, cutting knife; 361, adjusting wheel; 362, electric push rod; 363, tooth plate; 37, pressing frame; 41, supporting frame; 42, moving strip; 43, rectangular cavity; 44, guide groove plate. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments 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.

[0050] A preparation device for nanofiber sound-absorbing cotton in the medium and low frequency bands is used to prepare the sound-absorbing cotton used in the tires of new energy vehicles. Specifically, the layered product sound-absorbing cotton is made of fiber materials. During the preparation of the sound-absorbing cotton, its surface is cleaned for cutting.

[0051] like Figure 1-Figure 17As shown, a preparation device for nanofiber sound-absorbing cotton in the medium and low frequency bands comprises a base 1, two symmetrically arranged side plates 2 are fixedly installed on one side of the base 1 through a long plate, two heat-sealing rollers 220 are rotatably installed between the two side plates 2 and arranged up and down, a receiving frame 23 connected to the side plate 2 is provided on the side away from the two heat-sealing rollers 220, the upper receiving frame 23 and the side plate 2 are slidably connected, a wiping sponge 230 in contact with the heat-sealing roller 220 is provided in the receiving frame 23, a placing frame 26 is fixedly installed on one side of the two hot plates 2, two circular holes arranged up and down are symmetrically opened on the two placing frames 26, cleaning buckets 261 are fixedly installed in the circular holes, and cleaning ports are horizontally opened on the sides of the two cleaning buckets 261 that are close to each other, a positioning frame 31 is fixedly installed on the other side of the base 1, a plurality of cutting components are arranged on the positioning frame 31, a supporting frame 41 fixedly connected to the base 1 is provided below the positioning frame 31, and a plurality of guide components connected to the cutting components are slidably installed on the supporting frame 41.

[0052] By opening the upper and lower heat-sealing rollers 220, the sound-absorbing cotton passing below and the non-woven fabric on its surface can be heat-sealed, and the sound-absorbing cotton can be pushed by the mutual rotation of the two heat-sealing rollers 220. At the same time, when the heat-sealing rollers 220 rotate, they contact the wiping sponge 230, so that the water in the wiping sponge 230 is evenly smeared on the surface of the heat-sealing roller 220 to moisten the surface, thereby reducing the temperature of the surface of the heat-sealing roller 220. On the one hand, it can avoid the situation where the heat-sealing roller 220 is too high when heat-sealing the sound-absorbing cotton, causing the sound-absorbing cotton to be damaged. On the other hand, it can also make the fibers on the surface of the sound-absorbing cotton adhere to each other when the wet surface of the heat-sealing roller 220 contacts the sound-absorbing cotton, further aggravating the For cleaning during the preparation of the sound-absorbing cotton, by setting the cleaning barrel 261, when the sound-absorbing cotton enters under the two cleaning barrels 261 before the surface of the sound-absorbing cotton is heat-sealed, the cleaning barrel 261 can absorb the residual cotton wool adhered to the surface of the sound-absorbing cotton, so as to avoid the residual cotton wool adhering to the surface of the sound-absorbing cotton during preparation. By setting the cutting component, the sound-absorbing cotton can be pressed and cut in batches, so as to avoid the problem of difficulty in cutting the sound-absorbing cotton due to its own soft material, and it can also meet the cutting requirements of different specifications (the sound-absorbing cotton prepared in this application has a noise reduction capacity of 200Hz30%, so the batch-cut sound-absorbing cotton is used in the tire, so that the noise reduction of the tire is greatly improved when the new energy vehicle is driving, such as Fig.10 shown).

[0053] The sound-absorbing cotton in the present invention is based on the independently developed flash spray technology and die head and spinneret to develop and establish a variety of polymer material nanofiber manufacturing methods. Our research data on various applications of fibers show that fibers of different thicknesses mixed in a certain proportion and combined with different porosities will produce some very special effects (such as Fig.11As shown in the figure), it can be used in a variety of scenarios, such as multi-band sound absorption and sound insulation, thermal insulation, filtration, antibacterial, lightweight, etc. In addition, in the field of sound absorption, by changing the fiber thickness ratio, porosity and thickness, it can correspond to various frequency bands of sound absorption and sound insulation (such as Fig.12 shown).

[0054] Research material modification technology to improve the thermal fluidity of the material itself to make it easier to fiberize. Research the velocity distribution of the nozzle jet and the precise simulation technology of temperature distribution. Research the relationship between velocity distribution and fiber diameter distribution to improve the quality of the fiber. At the same time, research the large-scale, automated, and green preparation technology of materials to reduce processing costs and solve industry problems such as the difficulty in mass production of nano-grade fibers and environmental pollution.

[0055] Telescopic tubes 231 communicating with the inner cavity thereof are fixedly installed at equal intervals on the upper end surface of the upper receiving rack 23, and a water tank 24 is fixedly installed on one end of the multiple telescopic tubes 231 away from the upper receiving rack 23, the water tank 24 is communicated with the inner cavity of the telescopic tubes 231, a plug 232 fixedly connected to the wiping sponge 230 is provided in the telescopic tube 231, the upper part of the plug 232 is made of rubber, L-shaped fixing blocks 240 are fixedly installed on both sides of the lower end surface of the water tank 24, the fixing block 240 is fixedly connected to the top of the side plate 2 away from the water tank 24, a rectangular groove is opened in the middle of the fixing block 240, a connecting plate 241 fixedly connected to the receiving rack 23 is slidably installed in the rectangular groove, and a spring is commonly installed between the connecting plate 241 and the fixing block 240.

[0056] When the wiping sponge 230 needs to be filled with water, the water content of the wiping sponge 230 decreases after being used for a certain period of time. At this time, the weight of the wiping sponge 230 and the upper storage rack 23 becomes lighter. Therefore, the upper storage rack 23 is lifted upward under the action of the spring. When the upper storage rack 23 moves upward, the connecting plate 241 slides upward in the rectangular groove opened in the middle of the fixed block 240. At this time, the upper storage rack 23 compresses the telescopic tube 231, and at the same time, the plug 232 follows the retraction. The upward movement of the receiving rack 23 is synchronized with the upward movement of the receiving rack 23, thereby removing the blockage at the connection between the telescopic tube 231 and the water tank 24. At this time, the water in the water tank 24 is used to inject water into the wiping sponge 230 in the upper receiving rack 23 through the telescopic tube 231. When the water flows into the telescopic tube 231, due to the setting of the outer tube 233, the water in the telescopic tube 231 is also retained in the side box 234. Finally, the water in the side box 234 is injected into the wiping sponge 230 in the lower receiving rack 23 through the water pipes 235 on both sides to moisten the wiping sponge 230.

[0057] When the wiping sponge 230 does not need to be injected, after the wiping sponge 230 on the upper side reaches a certain weight, due to the application of weight to the spring, the connecting plate 241 slides downward in the rectangular groove opened in the middle of the fixed block 240, and the upper receiving frame 23 and the wiping sponge 230 inside it move downward synchronously. When the upper wiping sponge 230 moves downward, the plug 232 is pulled downward so that the plug 232 blocks the connection between the telescopic tube 231 and the water tank 24. At this time, the water in the water tank 24 stops adding water to the wiping sponge 230.

[0058] A center wheel 21 is installed in the middle of the side panel 2 on one side through motor rotation, and side wheels 22 are provided on the upper and lower sides of the center wheel 21 to be rotatably connected to the side panel 2, and the upper and lower side wheels 22 are fixedly connected to the upper and lower heat-sealing rollers 220 respectively, and a cam 253 is fixedly installed on the side of the center wheel 21 away from the side panel 2, and a push-pull plate 254 is rotatably installed on one side of the cam 253 through a round rod, and a fixed frame 25 fixedly connected to the side panel 2 is provided below the push-pull plate 254, and a compression box 251 is fixedly installed in the middle of the fixed frame 25, and a compression rod 252 is slidably installed in the compression box 251, and one end of the compression rod 252 is located inside the compression box 251 as a piston, and the push-pull plate 254 is located at one end away from the cam 253 and slides in the compression rod 252.

[0059] The motor is turned on to drive the center wheel 21 to rotate, and when the center wheel 21 rotates, it drives the upper and lower side wheels 22 to rotate towards each other through meshing synchronization. When the two side wheels 22 rotate towards each other, the two heat sealing rollers 220 rotate synchronously. During the rotation, on the one hand, the upper and lower surfaces of the sound-absorbing cotton can be heat-sealed synchronously, and on the other hand, the sound-absorbing cotton can be transported.

[0060] When the center wheel 21 rotates, it can also drive the cam 253 to rotate. When the cam 253 rotates, it drives the push-pull plate 254 to rotate, so that the push-pull plate 254 reciprocates and compresses the compression rod 252 when rotating. When the compression rod 252 reciprocates and compresses in the compression box 251, the gas in the compression box 251 is transmitted to the blowing plate 257 through the connecting pipe 256, and finally blown out through the blowing port on the blowing plate 257. Through the setting of the blowing plate 257, the upper and lower heat-sealing rollers 220 can be cooled when heat-sealing the sound-absorbing cotton. On the other hand, the fibers on the sound-absorbing cotton can also be blown off and cleaned.

[0061] An air transfer box 255 is fixedly installed on one side of the compression box 251. The air transfer box 255 is connected with connecting pipes 256 at the top and bottom. The connecting pipe 256 is connected to a blowing plate 257 fixed to the side plate 2 at one end away from the air transfer box 255. The blowing plate 257 is provided with a blowing port on the side close to the heat sealing roller 220.

[0062] An outer tube 233 connected to the inner cavity of the telescopic tube 231 is fixedly installed at one end of the telescopic tube 231, and a side box 234 is fixedly installed between multiple outer tubes 233. Water pipes 235 connected to the inner cavity are fixedly installed on both sides of the side box 234. The end of the water pipe 235 away from the side box 234 supplies water to the sponge in the lower side storage rack 23.

[0063] A collecting bin 262 is rotatably mounted on one side of the cleaning barrel 261 , a material discharge port 263 is provided at the lower portion of the collecting bin 262 , a dust suction groove 265 is circumferentially provided at one side of the collecting bin 262 close to the cleaning barrel 261 , and a fan 264 is provided in the middle of the collecting bin 262 .

[0064] When the sound-absorbing cotton passes through the upper and lower cleaning barrels 261, the fan 264 is turned on. The fan 264 can be turned on to suck in and collect the cotton wool on the surface of the sound-absorbing cotton.

[0065] A dovetail groove 32 is horizontally opened in the middle of the positioning frame 31, and multiple movable plates 33 are slidably installed in the dovetail groove 32. The front side of the movable plate 33 is fixedly connected to the cutting assembly, and a circular shaft 330 is fixedly installed on the upper part of the movable plate 33. A shaped frame 34 is fixedly installed on both sides of the positioning frame 31. A threaded rod 340 is installed in the middle of the shaped frame 34 through motor rotation. A connecting piece 341 is threadedly installed on the threaded rod 340, and a lifting plate 342 is fixedly installed between the connecting pieces 341 on both sides. The lifting plate 342 is provided with adjustment grooves 343 for respectively sleeved the circular shaft 330.

[0066] The cutting assembly includes a mounting frame 35, a cutting knife 36 is rotatably mounted on the middle part of the mounting frame 35 via a rotating shaft, an adjusting wheel 361 is fixedly mounted on one end of the rotating shaft, an electric push rod 362 fixedly connected to the mounting frame 35 is provided above the adjusting wheel 361, a tooth plate 363 meshing with the adjusting wheel 361 is fixedly mounted on the telescopic end of the electric push rod 362, a connecting plate 351 fixedly connected to the mounting frame 35 is horizontally arranged above the cutting knife 36, a pressing frame 37 sleeved on the outside of the rotating shaft is provided on the outside of the cutting knife 36, and a spring is commonly connected between the connecting plate 351 and the pressing frame 37.

[0067] The cutting knife 36 can be used to cut the sound-absorbing cotton that is pushed over, and the spring and pressing frame 37 outside the cutting knife 36 can enable the pressing frame 37 to press the surface of the sound-absorbing cotton to avoid deviation and damage during cutting due to the soft material of the sound-absorbing cotton itself, and the guide groove plate 44 can be used to guide and support the cutting knife 36 when cutting the sound-absorbing cotton.

[0068] The guide assembly includes a moving bar 42 slidably connected to the supporting frame 41, a rectangular cavity 43 is opened in the moving bar 42, a plurality of springs are fixedly installed in the rectangular cavity 43, and a guide groove plate 44 located on the supporting frame 41 is commonly installed at one end of the plurality of springs away from the rectangular cavity 43.

[0069] Another object of the present invention is to provide a method for preparing nanofiber sound-absorbing cotton in the mid- and low-frequency bands, comprising the following steps:

[0070] S1: Sound-absorbing cotton flash steaming:

[0071] The high molecular organic material is melted, and the blown fibers are intertwined with each other by flash evaporation, and then the non-woven fabric is compounded on both sides of the primary sound-absorbing cotton to form a sound-absorbing cotton product;

[0072] S2: Pressing and cleaning of sound-absorbing cotton:

[0073] The two heat-sealing rollers 220 rotate relative to each other to heat-press the sound-absorbing cotton, so that the non-woven fabric on the surface of the sound-absorbing cotton is pressed against each other, and the sound-absorbing cotton can be pushed when the two heat-sealing rollers 220 rotate relative to each other, and the heat-sealing rollers 220 can clean the excess fiber impurities on the surface of the sound-absorbing cotton when the heat-sealing rollers 220 are in contact with the sound-absorbing cotton;

[0074] S3: Cutting of sound-absorbing cotton:

[0075] The pressed and cleaned sound-absorbing cotton can be cut into multiple pieces by the setting of multiple cutting knives 36 when passing through the cutting assembly, and the spacing between the multiple cutting knives 36 can be adjusted by lifting and lowering the lifting plate 342 to meet the cutting width of different requirements for the sound-absorbing cotton.

[0076] When the present invention is used, the sound-absorbing cotton needs to be prepared in advance, the high molecular organic material is melted, the blown fibers are intertwined by flash evaporation, and then the non-woven fabric is compounded on both sides of the primary sound-absorbing cotton to form a sound-absorbing cotton product. When the flash evaporation method in the present invention is used to manufacture fibers, the fibers are mixed in a certain proportion with different thicknesses and combined with different porosities to produce some very special effects, so that it can correspond to a variety of scenes, such as multi-band sound absorption and sound insulation, thermal insulation, filtration, antibacterial, and lightweight. In addition, in the field of sound absorption, by changing the thickness ratio, porosity, and thickness of the fibers, it is possible to correspond to sound absorption and sound insulation in various frequency bands;

[0077] The sound-absorbing cotton prepared is based on the technical improvement and combination of melt-blowing method and flash evaporation method (flash-blowing method).

[0078] The fibers with a normal fiber diameter distribution and an average fiber diameter of 5-8 μm prepared by flash spraying were adjusted to an apparent density of 0.05 g / cm 3When (porosity = 1-(apparent density / material density)) is below, the fiber assembly will have the following performance parameters:

[0079] Porosity: >95%;

[0080] Lost degree: 1-1.4;

[0081] Sound absorption rate of 200-400Hz: ≥65%;

[0082] Sound absorption rate of 400-800Hz: ≥95%;

[0083] 800-5000Hz sound absorption rate: ≥99%;

[0084] (Note: Rail transit (tire noise) tire noise frequency range → 20-20000Hz)

[0085] (Note: High-end equipment (machine) frequency range → 200 and above)

[0086] A low-cost and high-efficiency method for preparing nanofibers has been successfully established. The die head and spinneret have been successfully optimized by using 3D-CFD fluid analysis and a large number of experiments, and can be used for a variety of polymer materials. Some experimental data of the flash spraying method are as follows:

[0087] Longitudinal elastic modulus: >10KPa;

[0088] Average fiber diameter: 5-8 microns;

[0089] Fiber diameter distribution: normal distribution;

[0090] Coefficient of variation: 45%-65%;

[0091] Average sound absorption rate above 400Hz: ≥0.8;

[0092] Fluid resistance: >10000Ns / m^4.

[0093] The parameters of the flash evaporation device are adjusted so that the average fiber diameter of the first polymer fiber is normally distributed.

[0094] While controlling the average fiber diameter, fibers with a certain ratio can be ejected at one time, effectively solving this problem. Specifically, nanofiber composites have shown their unique value in the field of acoustics. Thanks to their ultra-high specific surface area, porosity and 3D structure, this material shows excellent performance in processing sound waves. More specifically, when the fiber size decreases, the number increases and the spacing decreases, while keeping the density unchanged, the sound wave will lose energy due to viscous friction and heat exchange when passing through each fiber (see Fig.11In addition, its porous structure causes multiple reflections and scattering of sound, providing an efficient means of absorbing low-frequency noise (see Fig.12 ), these unique properties, combined with the tunability of nanofibers, allow for the opportunity to fine-tune the material structure, such as changing the fiber arrangement, thereby enhancing its sound absorption performance and broadening its frequency range of application, and then performing the initial processing of the sound-absorbing cotton;

[0095] The above-mentioned flash spraying method adjusts the average fiber diameter of the material to 500nm-1μm with a normal fiber diameter distribution to an apparent density of 0.15-0.2g / cm 3 When the fiber assembly is shaped like a ball, it will have the following performance parameters:

[0096] Porosity: 90%-95%;

[0097] 200-500Hz sound insulation: 60dB;

[0098] 1000-5000Hz sound insulation: 40dB;

[0099] Longitudinal elastic modulus: >300KPa;

[0100] Average fiber diameter: 0.8 μm;

[0101] Fiber diameter distribution: close to normal distribution;

[0102] Fluid resistance: >7000000Ns / m^4

[0103] The opening of the upper and lower heat-sealing rollers 220 can heat-seal the sound-absorbing cotton passing below and the non-woven fabric on its surface, and the mutual rotation of the two heat-sealing rollers 220 can also push the sound-absorbing cotton. At the same time, when the heat-sealing rollers 220 rotate, they contact with the wiping sponge 230, so that the water in the wiping sponge 230 is evenly smeared on the surface of the heat-sealing roller 220 to moisten the surface of the heat-sealing roller 220, thereby reducing the temperature of the surface of the heat-sealing roller 220. On the one hand, it can avoid the situation that the heat-sealing roller 220 is too high when heat-sealing the sound-absorbing cotton, causing damage to the sound-absorbing cotton. On the other hand, it can also make the heat-sealing roller 220 When the wet surface contacts the sound-absorbing cotton, the fibers on the surface of the sound-absorbing cotton will adhere to it, which further aggravates the cleaning of the sound-absorbing cotton during preparation. By setting the cleaning barrel 261, when the sound-absorbing cotton enters under the two cleaning barrels 261 before heat-sealing the surface of the sound-absorbing cotton, the cleaning barrel 261 can absorb the residual cotton wool adhered to the surface of the sound-absorbing cotton, thereby avoiding the residual cotton wool adhered to the surface during preparation of the sound-absorbing cotton. By setting the cutting component, the sound-absorbing cotton can be pressed and cut in batches, thereby avoiding the problem of difficulty in cutting the sound-absorbing cotton due to its own soft material, and can also meet the cutting requirements of different specifications;

[0104] When the wiping sponge 230 needs to be filled with water, the water content of the wiping sponge 230 decreases after being used for a certain period of time. At this time, the weight of the wiping sponge 230 and the upper storage rack 23 becomes lighter. Therefore, the upper storage rack 23 is lifted upward under the action of the spring. When the upper storage rack 23 moves upward, the connecting plate 241 slides upward in the rectangular groove opened in the middle of the fixed block 240. At this time, the upper storage rack 23 compresses the telescopic tube 231, and at the same time, the plug 232 follows the storage rack 23. The frame 23 moves upward synchronously, thereby removing the blockage of the connection between the telescopic tube 231 and the water tank 24. At this time, the water in the water tank 24 is injected into the wiping sponge 230 in the upper receiving frame 23 through the telescopic tube 231. When the water flows into the telescopic tube 231, due to the setting of the outer tube 233, the water in the telescopic tube 231 is also retained in the side box 234. Finally, the water in the side box 234 is injected into the wiping sponge 230 in the lower receiving frame 23 through the water pipes 235 on both sides. When the wiping sponge 230 does not need to be injected, after the upper wiping sponge 230 reaches a certain weight, due to the weight applied to the spring, the connecting plate 241 slides downward in the rectangular groove opened in the middle of the fixing block 240, and the upper receiving frame 23 and the wiping sponge 230 inside it move downward synchronously. When the upper wiping sponge 230 moves downward, the plug 232 is pulled downward so that the plug 232 blocks the connection between the telescopic tube 231 and the water tank 24. At this time, the water in the water tank 24 stops adding water to the wiping sponge 230;

[0105] The motor is turned on to drive the center wheel 21 to rotate. When the center wheel 21 rotates, it drives the upper and lower side wheels 22 to rotate in opposite directions through meshing synchronization. When the two side wheels 22 rotate in opposite directions, the two heat-sealing rollers 220 rotate synchronously. When rotating, on the one hand, the upper and lower surfaces of the sound-absorbing cotton can be heat-sealed synchronously, and on the other hand, the sound-absorbing cotton can be transported. When the center wheel 21 rotates, it can also drive the cam 253 to rotate. When the cam 253 rotates, it drives the push-pull plate 254 to rotate, so that the push-pull plate 254 reciprocates the compression rod 252 when rotating. When the compression rod 252 reciprocates in the compression box 251, the gas in the compression box 251 is transmitted to the blowing plate 257 through the connecting pipe 256, and finally blown out through the blowing port on the blowing plate 257. Through the setting of the blowing plate 257, the upper and lower heat-sealing rollers 220 can be cooled when the sound-absorbing cotton is heat-sealed, and on the other hand, the fibers on the sound-absorbing cotton can be blown off and cleaned.

[0106] The setting of the cutting knife 36 can cut the sound-absorbing cotton pushed over, and the setting of the spring and the pressing frame 37 outside the cutting knife 36 can enable the pressing frame 37 to press the surface of the sound-absorbing cotton to avoid deviation and damage during cutting due to the soft material of the sound-absorbing cotton itself, and the setting of the guide groove plate 44 can guide and support the cutting knife 36 when cutting the sound-absorbing cotton.

[0107] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A preparation device for nanofiber sound-absorbing cotton in the mid-low frequency band, comprising a base (1), characterized in that: Two symmetrically arranged side plates (2) are fixedly mounted on one side of the base (1) via a long plate. Two heat-sealing rollers (220) arranged up and down are mounted between the two side plates (2) for co-rotation. A receiving frame (23) connected to the side plate (2) is provided on the side away from the two heat-sealing rollers (220). The upper receiving frame (23) is slidably connected to the side plate (2). A wiping sponge (230) in contact with the heat-sealing roller (220) is provided in the receiving frame (23). A wiping sponge (230) in contact with the heat-sealing roller (220) is fixedly mounted on one side of the two heat plates (2). A placing rack (26), two placing racks (26) are symmetrically provided with two circular holes arranged up and down, a cleaning bucket (261) is fixedly installed in each circular hole, a cleaning opening is transversely opened on the adjacent side of the two cleaning buckets (261), a positioning rack (31) is fixedly installed on the other side of the base (1), a plurality of cutting assemblies are arranged on the positioning rack (31), a supporting rack (41) fixedly connected to the base (1) is provided below the positioning rack (31), a plurality of guide assemblies connected to the cutting assemblies are slidably installed on the supporting rack (41).

2. The preparation device of the nanofiber sound-absorbing cotton in the medium and low frequency band according to claim 1 is characterized in that: Telescopic tubes (231) communicating with the inner cavity of the upper receiving frame (23) are fixedly installed at equal intervals on the upper end surface of the receiving frame (23) on the upper side. A water tank (24) is fixedly installed on one end of the plurality of telescopic tubes (231) away from the upper receiving frame (23). The water tank (24) is communicated with the inner cavity of the telescopic tubes (231). A plug (232) fixedly connected to the wiping sponge (230) is provided in the telescopic tube (231). The upper part of the plug (232) is made of rubber. L-shaped fixing blocks (240) are fixedly installed on both sides of the lower end surface of the water tank (24). The fixing block (240) is fixedly connected to the top of the side plate (2) on the side away from the water tank (24). A rectangular groove is provided in the middle of the fixing block (240). A connecting plate (241) fixedly connected to the receiving frame (23) is slidably installed in the rectangular groove. A spring is installed between the connecting plate (241) and the fixing block (240).

3. The preparation device of the nanofiber sound-absorbing cotton in the middle and low frequency band according to claim 1 is characterized in that: A center wheel (21) is installed in the middle of the side plate (2) on one side through a motor rotation, and side wheels (22) are provided on the upper and lower sides of the center wheel (21) for rotation connection with the side plate (2), and the upper and lower side wheels (22) are fixedly connected to the upper and lower heat-sealing rollers (220) respectively. A cam (253) is fixedly installed on the side of the center wheel (21) away from the side plate (2), and a push-pull plate (254) is rotationally installed on one side of the cam (253) through a round rod, and a fixed frame (25) fixedly connected to the side plate (2) is provided below the push-pull plate (254), and a compression box (251) is fixedly installed in the middle of the fixed frame (25), and a compression rod (252) is slidably installed in the compression box (251), and one end of the compression rod (252) located inside the compression box (251) is a piston, and one end of the push-pull plate (254) away from the cam (253) is located in the compression rod (252) and slides.

4. The preparation device of the nanofiber sound-absorbing cotton in the middle and low frequency band according to claim 3 is characterized in that: An air transfer box (255) is fixedly mounted on one side of the compression box (251), and the air transfer box (255) is connected to connecting pipes (256) at the top and bottom. The connecting pipe (256) is connected to a blowing plate (257) fixed to the side plate (2) at one end away from the air transfer box (255), and a blowing port is provided on the side of the blowing plate (257) close to the heat sealing roller (220).

5. The preparation device of the nanofiber sound-absorbing cotton in the middle and low frequency band according to claim 2, characterized in that: An outer tube (233) communicating with the inner cavity of the telescopic tube (231) is fixedly mounted on one end of the telescopic tube (231), a side box (234) is fixedly mounted between the plurality of outer tubes (233), water pipes (235) communicating with the inner cavity of the side box (234) are fixedly mounted on both sides of the side box (234), and one end of the water pipe (235) away from the side box (234) supplies water to the sponge in the lower receiving frame (23).

6. The preparation device of the nanofiber sound-absorbing cotton in the middle and low frequency band according to claim 1, characterized in that: A collecting bin (262) is rotatably mounted on one side of the cleaning barrel (261), a material discharge port (263) is provided at the lower portion of the collecting bin (262), a dust suction groove (265) is circumferentially provided at one side of the collecting bin (262) close to the cleaning barrel (261), and a fan (264) is provided in the middle of the collecting bin (262).

7. The preparation device of the nanofiber sound-absorbing cotton in the mid-low frequency band according to claim 1, characterized in that: A dovetail groove (32) is transversely provided in the middle of the positioning frame (31), and a plurality of movable plates (33) are slidably installed in the dovetail groove (32). The front side of the movable plate (33) is fixedly connected to the cutting assembly, and a circular shaft (330) is fixedly installed on the upper part of the movable plate (33). A shaped frame (34) is fixedly installed on both sides of the positioning frame (31). A threaded rod (340) is installed in the middle of the shaped frame (34) through motor rotation, and a connecting piece (341) is threadedly installed on the threaded rod (340). A lifting plate (342) is fixedly installed between the connecting pieces (341) on both sides, and the lifting plate (342) is provided with regulating grooves (343) for respectively sleeved the circular shaft (330).

8. The preparation device of the nanofiber sound-absorbing cotton in the mid-low frequency band according to claim 1, characterized in that: The cutting assembly comprises a mounting frame (35), a cutting knife (36) is rotatably mounted on the middle of the mounting frame (35) via a rotating shaft, an adjusting wheel (361) is fixedly mounted on one end of the rotating shaft, an electric push rod (362) fixedly connected to the mounting frame (35) is arranged above the adjusting wheel (361), a tooth plate (363) meshing with the adjusting wheel (361) is fixedly mounted on the telescopic end of the electric push rod (362), a connecting plate (351) fixedly connected to the mounting frame (35) is transversely arranged above the cutting knife (36), a pressing frame (37) sleeved on the outside of the rotating shaft is arranged outside the cutting knife (36), and a spring is commonly connected between the connecting plate (351) and the pressing frame (37).

9. The preparation device of the nanofiber sound-absorbing cotton in the middle and low frequency band according to claim 1, characterized in that: The guide assembly comprises a moving bar (42) slidably connected to a supporting frame (41), a rectangular cavity (43) is provided in the moving bar (42), a plurality of springs are fixedly installed in the rectangular cavity (43), and a guide slot plate (44) located on the supporting frame (41) is commonly installed at one end of the plurality of springs away from the rectangular cavity (43).

10. A method for preparing nanofiber sound-absorbing cotton in the mid-low frequency band, using the preparation device for nanofiber sound-absorbing cotton in the mid-low frequency band as claimed in claim 9 to prepare the sound-absorbing cotton, characterized in that: The preparation method of the sound-absorbing cotton comprises the following steps: S1: Sound-absorbing cotton flash steaming: The high molecular organic material is melted, and the blown fibers are intertwined with each other by flash evaporation, and then the non-woven fabric is compounded on both sides of the primary sound-absorbing cotton to form a sound-absorbing cotton product; S2: Pressing and cleaning of sound-absorbing cotton: The two heat-sealing rollers (220) rotate relative to each other to heat-press the sound-absorbing cotton, so that the non-woven fabric on the surface of the sound-absorbing cotton is pressed against each other, and the sound-absorbing cotton can be pushed when the two heat-sealing rollers (220) rotate relative to each other, and the heat-sealing rollers (220) can clean excess fiber impurities on the surface of the sound-absorbing cotton when the heat-sealing rollers (220) are in contact with the sound-absorbing cotton; S3: Cutting of sound-absorbing cotton: When the pressed and cleaned sound-absorbing cotton passes through the cutting assembly, the sound-absorbing cotton can be cut into multiple pieces by means of the arrangement of multiple cutting knives (36), and the spacing between the multiple cutting knives (36) can be adjusted by lifting and lowering the lifting plate (342), thereby meeting the cutting width required for different sound-absorbing cotton pieces.

Images