A wide web dry film powder coating apparatus and method

Abstract

This invention belongs to the field of energy storage device fabrication technology, specifically a wide-width dry powder film fabrication apparatus and method. It includes a frame assembly and, from top to bottom, a reciprocating guide discharge device, a powder agglomeration device, a powder agglomeration felting device, a felt roller pressing device, and a supporting device mounted on the frame assembly. The apparatus combines powder agglomeration feeding with wide-width dispersion by a rotating needle wheel for quantitative powder agglomeration. It can also adjust the powder discharge width to manufacture or composite self-supporting films with different width requirements. This invention overcomes the limitation of existing continuous fabrication technologies where powder agglomerates cannot be used to fabricate wide-width self-supporting films in a loose state. It effectively improves the precision of original fibrous dry powder film fabrication and comprehensively enhances the production technology level of energy storage devices.

Description

Technical Field

[0001] This invention belongs to the field of energy storage device fabrication technology, specifically a wide-width dry powder film preparation device and method, which can be used for wide-width dry powder film preparation of positive and negative electrodes of high-capacity ion batteries, solid electrolytes and supercapacitor electrodes. Background Technology

[0002] Currently, the solvent-free dry method for preparing self-supporting membranes for energy storage devices mainly adopts the patent of Maxwell House, Inc., published on February 26, 2021, with publication number CN112424973A and invention title "Composition and method for dry electrode membranes with reduced binder content". After the active material and binder polytetrafluoroethylene (PTFE) are sheared into fibrillated powder, a preliminary film is formed by spreading followed by vertical roller pressing or screw extrusion, and then the self-supporting membrane is gradually thinned and compacted to the target thickness by differential rollers. This process has two inherent problems. First, after the raw material is fibrillated into powder, the interparticle viscosity is relatively high. During the manual or automatic spreading to the roller gap of the press and extrusion into the film forming process, the powder particles are easily stretched, resulting in local excess or deficiency of powder. This leads to over-compaction points, wrinkles, or local holes in the film material, and the edges of the film are often uneven. Subsequent processes require more cutting, often resulting in material waste. Second, during screw extrusion film forming, the excessive shearing of the powder fibers and the high stress during extrusion can affect the plasticity of the binder fibers, often resulting in an excessively high initial compaction density of the powder film, which is not conducive to the subsequent gradual thinning process. Both of these problems limit the development of fibrillation dry process technology in the production of wide-width films. The solution lies in uniformly dispersing the powder particles and simultaneously rolling the film at the initial stage of film formation. Summary of the Invention

[0003] In order to solve the problem that powder particles cannot be used to prepare wide-width self-supporting films in a loose state in existing continuous preparation technologies, the present invention aims to provide a wide-width dry powder film preparation device and method.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] The wide-width dry powder film preparation apparatus of the present invention includes a frame assembly and, from top to bottom, a reciprocating guide and discharge device, a powder agglomeration device, a powder agglomeration felting device, a felting roller pressing device, and a supporting device, all mounted on the frame assembly. The reciprocating guide and discharge device includes a powder conveying pipe capable of reciprocating on the frame assembly. The powder agglomeration device includes a distribution hopper and a stirring and leveling device. The distribution hopper is fixed on the frame assembly and located below the powder conveying pipe. The stirring and leveling device is disposed within the distribution hopper to stir and level the powder agglomerates falling into the hopper. The powder agglomeration device includes a main rotating needle wheel and at least one satellite rotating needle wheel. The main rotating needle wheel and the satellite rotating needle wheels are rotatably mounted on the frame assembly and driven to rotate by a needle wheel power source. The main rotating needle wheel is located below the distribution hopper. The powder agglomerates are formed into a powder agglomerate felt on the surface of the main rotating needle wheel through the meshing of the main rotating needle wheel and the satellite rotating needle wheel; the felt rolling device includes multiple sets of differential rollers arranged from top to bottom, with two differential rollers in each set rotatably mounted on the frame assembly and driven to rotate in opposite directions by a differential roller power source. The powder agglomerate felt passes between the two differential rollers in the first set of differential rollers and is rolled into a self-supporting blank, and then passes between the two differential rollers in the remaining differential roller sets and is rolled into a target self-supporting film; the carrying device includes a conveyor belt and a heating support assembly, the heating support assembly is set at the bottom of the frame assembly, the conveyor belt runs from one side of the frame assembly to the other side, and is supported and heated by the heating support assembly when passing through it, the target self-supporting film falls on the conveyor belt and is carried by the conveyor belt.

[0006] Preferably, the top of the frame assembly is provided with a reciprocating slide (204) capable of reciprocating, and the powder conveying pipe is mounted on the reciprocating slide;

[0007] And / or, the lower end of the powder conveying pipe is connected to a vibrating sleeve.

[0008] Preferably, the reciprocating slide table includes a reciprocating slider and slide rail drive wheels, and slide rail drive wheels are provided on both sides of the sliding direction of the reciprocating slider; a powder conveying pipe slide rail is installed on the top of the frame assembly, and the slide rail drive wheels roll on the powder conveying pipe slide rail driven by a power source.

[0009] Preferably, the stirring and leveling device includes a rotary comb gear and a rotary comb gear driver. The rotary comb gear driver is fixed on the frame assembly. The rotary comb gear is located inside the distribution hopper and above the outlet. The axial direction of the rotary comb gear is consistent with the width direction of the distribution hopper. The output end of the rotary comb gear driver is connected to the rotary comb gear and drives the rotary comb gear to rotate.

[0010] And / or, the axial length of the rotating comb gear is greater than or equal to the width of the distribution hopper, and at least one set of comb gears is embedded on the rotating shaft surface of the rotating comb gear in the circumferential direction. Each comb tooth in each set is equidistant from the axial direction of the rotating shaft. Each comb tooth in each set contacts the powder clumps flowing out from the lower end of the powder conveying pipe, stirs and flattens the powder clumps in the width direction of the distribution hopper, and provides downward pressure.

[0011] And / or, the width direction of the distribution hopper is consistent with the reciprocating sliding direction of the powder conveying pipe, the width of the distribution hopper covers the movement trajectory of the lower end of the powder conveying pipe during the reciprocating sliding process, and the powder clumps flowing out of the lower end of the powder conveying pipe are received by the distribution hopper and accumulate along the width direction of the distribution hopper.

[0012] Preferably, a detachable and replaceable brush powder blocker is provided at the bottom outlet of the dispensing hopper. The brush powder blocker includes a brush handle with brushes. The brush handle is detachably installed on the outer surface of the side wall of the dispensing hopper on the side opposite to the rotation direction of the main rotating needle wheel. The brush end extends from the side to the bottom of the dispensing hopper and overlaps with the needle part on the main rotating needle wheel to prevent powder clumps from leaking out from the side.

[0013] Preferably, the needle length on the main rotating needle wheel is equal to the needle length on the satellite rotating needle wheel, the needle tip on the main rotating needle wheel abuts against the surface of the satellite rotating needle wheel, and the needle tip on the satellite rotating needle wheel abuts against the surface of the main rotating needle wheel;

[0014] And / or, the needle surface on the main rotating needle wheel and the needle surface on the satellite rotating needle wheel both have barb structures;

[0015] And / or, when there are multiple satellite rotating pinwheels, the last satellite rotating pinwheel is located on one side of the powder clump felt and on the opposite side of the powder clump discharge in the distribution hopper, and serves as a guide wheel for guiding the powder clump felt out; the remaining satellite rotating pinwheels are located on the other side of the powder clump felt and on the same side as the powder clump discharge side in the distribution hopper.

[0016] And / or, a vibratory cleaner for cleaning the main rotating pinwheel is provided on the opposite side of the powder discharge from the distribution hopper, and the vibratory cleaner is mounted on the frame assembly;

[0017] And / or, one end of the main rotating needle wheel is connected to a needle wheel power source, and the other end of the main rotating needle wheel is provided with a negative pressure recovery pipe installed on the frame assembly.

[0018] Preferably, the differential roller group is divided into two groups arranged vertically. The first group of differential rollers located at the top is the primary differential roller group for the first rolling of the powder felt, and the second group of differential rollers located at the bottom is the secondary differential roller group for the subsequent rolling and thinning of the powder felt.

[0019] And / or, the two primary differential rollers of the primary differential roller group have equal roller diameters, one of the two primary differential rollers is fixed, and the other roller gap width is adjusted according to the different materials of the powder, and then fixed after adjustment; the two secondary differential rollers of the secondary differential roller group have equal roller diameters, one of the two secondary differential rollers is fixed, and the other roller gap width is adjusted according to the different materials of the powder, and then fixed after adjustment.

[0020] Preferably, the heating support assembly includes an electric heating plate and a support frame. The support frame is fixed to the bottom of the frame assembly where it is placed on the ground, and the electric heating plate is installed on the top of the support frame for heating the transport belt.

[0021] And / or, the support frame is a height-adjustable telescopic frame.

[0022] The wide-width dry powder film preparation method of the present invention includes the following steps:

[0023] Step A: Set the heating temperature of the electric heating plate and start heating; measure the surface temperature of the electric heating plate to the set temperature; lay the conveyor belt on the electric heating plate and start the conveyor belt feeding process.

[0024] Step B: Start the stirring and leveling device in the distribution hopper to make the stirring and leveling device reach the target speed;

[0025] Step C: The powder clumps are conveyed to the powder conveying pipe, and the powder clumps flow out through the powder conveying pipe to the distribution hopper;

[0026] Step D: The powder conveying pipe reciprocates at a set speed, and the powder clumps are spread into the distribution hopper. The main rotating pinwheel, satellite rotating pinwheel and each group of differential rollers are started.

[0027] Step E: The powder clumps in the dispensing hopper are discharged by the rotating and meshing main rotating needle wheel and satellite rotating needle wheel, and powder clump felt is formed on the surface of the main rotating needle wheel;

[0028] Step F: The powder felt is rolled and processed into a self-supporting blank by passing between two differential rollers in the first group of differential rollers, and then rolled and processed into the target self-supporting film by passing between two differential rollers in the remaining differential roller groups.

[0029] Step G involves sampling and measuring the thickness and compaction density of the target self-supporting film. The target self-supporting film, after being rolled by the differential roller group, can achieve self-supporting winding or be transported to the winding mechanism via the conveyor belt.

[0030] Preferably, in step C, the powder granules are first dried to obtain dried powder, and then the dried powder is transported to the powder conveying pipe through a positive and negative pressure airflow conveying system.

[0031] And / or, in step C, a vibrating sleeve is installed at the lower end of the powder conveying pipe to maintain the vibration frequency of the vibrating sleeve, so that the powder flow rate in the powder conveying pipe is uniform and constant.

[0032] And / or, the needle length of the main rotating needle wheel and the satellite rotating needle wheel is 1.0 to 50.0 mm, and the material is stainless steel; the main rotating needle wheel is set with a linear velocity so that the depth of the powder clumps in the distribution hopper remains constant, that is, the feeding rate and the discharging rate are the same, and the powder inlet and outlet rates are calculated; the satellite rotating needle wheel is set with a linear velocity that is the same as that of the main rotating needle wheel, and the needles on the main rotating needle wheel and the satellite rotating needle wheel are staggered and contact each other's rollers respectively;

[0033] And / or, a vibrating cleaner is installed on the opposite side of the powder clump in the distribution hopper. The frequency of the vibrating cleaner is 10 to 500 Hz, and the negative pressure has no fixed range, as long as fiber recovery is achieved.

[0034] And / or, the temperature range of the differential roller is room temperature to 200℃; a primary differential roller group and a secondary differential roller group are arranged below the main rotating needle wheel. The roller speed of the slow roller in the two primary differential rollers in the primary differential roller group is set to n cm / min, and the falling speed of the powder felt is the same as the linear speed of the main rotating needle wheel, so that the powder felt will not be crowded at the roller gap of the two primary differential rollers. The roller pressure of the primary differential roller is 0.5 to 5 t, and the differential ratio is 1.0 to 3.0; the linear speed of the slow roller in the two secondary differential rollers in the secondary differential roller group is the same as the film exit speed of the upper differential roller, and the speed is the roller speed of the slow roller in the primary differential roller group multiplied by the differential ratio, so as not to cause the self-supporting blank to be crowded at the roller gap of the two secondary differential rollers; the target self-supporting film after the roller pressing of the primary differential roller group and the secondary differential roller group can be self-supported and wound up or transported to the winding mechanism by a conveyor belt.

[0035] Preferably, the output speed of the target self-supporting membrane is x cm / min, the target thickness of the target self-supporting membrane is y cm, the width of the target self-supporting membrane is z cm, and the compaction density of the target self-supporting membrane is ρ1 g / cm³. 3 Assuming the target self-supporting film is stretched only along the conveyor belt direction during calendering, with a constant width, the powder output rate is k = x×y×z×ρ1 g / min, the width of the distribution hopper is z cm, and the powder inside the distribution hopper is a compacted powder layer with a compacted density of ρ2 g / cm³. 3 The depth and cross-sectional area are a cm. 2 The powder output mass of the distribution hopper is h = a×z×ρ2 g, and the time required to empty the distribution hopper once is t = h / k min. The time for the reciprocating guide discharge device to reciprocate once in one direction is less than the time t min required to empty the distribution hopper once, so as to maintain the synchronous descent of powder across the entire width.

[0036] And / or, the axial length of the main rotating needle wheel is greater than the discharge width of the distribution hopper, ensuring that all the discharged powder clumps and felt are carried out by the needles on the surface of the main rotating needle wheel. The set rotation speed of the main rotating needle wheel requires that the depth of the compacted powder layer in the distribution hopper remains constant, that is, the feeding rate and the discharge rate of the distribution hopper are the same. The linear velocity of the main rotating needle wheel is calculated as follows: the volume difference between the top of the two cylinders from the roller radius r of the main rotating needle wheel to the needle length h is l = z × π × (r + h). 2 - z×π×r 2 cm 3 , using l cm 3 Subtract the volume occupied by all needles, i.e., the number of needles per square centimeter (i / cm). 2 Multiply by the surface area of ​​the roller root, j cm 2 Multiply by the volume of each needle, q cm 3 This refers to the volume occupied by the powder, the ratio of the powder-covered roller surface area to the total surface area (m), the discharge volume of the fan-shaped powder discharge zone p = (li × j × q) × m mL, the actual to theoretical powder outflow ratio is w = (p / m) / l and w < 1, and the radial equivalent cross-sectional area of ​​the fan-shaped powder discharge zone is s = z × h cm. 2 The linear velocity of the main rotating needle wheel is n = (p / s) / w cm / min;

[0037] And / or, the rolling temperature range of the differential roller is room temperature to 200℃; the slow roller speed of the primary differential roller is set to n cm / min, the falling speed of the powder clump felt is the same as the linear speed of the main rotating needle wheel, and the linear speed of the slow roller in the primary differential roller is the same as the falling speed of the powder clump felt, so that the powder clump felt will not be squeezed at the roller gap of the primary differential roller. The rolling pressure and differential speed ratio are set according to the actual material requirements; the linear speed of the slow roller in the two secondary differential rollers is the same as the film exit speed of the upper differential roller, and the speed prediction is the slow roller speed in the primary differential roller group multiplied by the differential speed ratio, so as not to cause the target self-supporting film to be squeezed at the roller gap.

[0038] The advantages and positive effects of this invention are as follows:

[0039] 1. The present invention overcomes the problems of uneven powder distribution and excessively high initial film compaction density by adopting a linear synchronous powder discharge mode. The mode of synchronous powder distribution with constant speed powder distribution and rotating needle wheel reduces the distribution deviation of powder in both the film width and belt travel directions.

[0040] 2. The present invention uses a rotating comb gear located in the distribution hopper to evenly distribute and disperse the reciprocatingly sprinkled powder clumps, while applying a certain pressure to press the powder clump layer to the main rotating needle wheel for extraction.

[0041] 3. The present invention adopts a mode combining a distribution hopper and a main rotating pinwheel to synchronously and uniformly output the reciprocatingly spread powder clumps along the width direction. Combined with the rotating comb gear, it avoids uneven feeding in the width direction caused by uneven pulling of powder clumps in the hopper.

[0042] 4. This invention employs multiple sets of satellite rotating needle wheels to perform needle punching with the main rotating needle wheel. The needles carry the fibers out and into the powder layer, forming powder felt on the surface of the main rotating needle wheel. Multi-stage needle punching gradually combs the felt, improving the uniformity of powder distribution and the consistency of pores.

[0043] 5. This invention employs multiple sets of differential rollers to progressively roll and compact the exported powder agglomerates and felt. The primary differential roller set stretches and kneads the powder agglomerates and felt into a self-supporting film preform, and gradually reduces the gap between the differential rollers to increase the rolling pressure, ultimately obtaining the target self-supporting film with the target thickness and porosity. Attached Figure Description

[0044] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can choose various possible shapes and proportions to implement the invention according to specific circumstances. Throughout the drawings, the same reference numerals denote the same components. In the drawings:

[0045] Figure 1 This is a front view of the structure of the wide-width dry powder film preparation device of the present invention from the direction of entry of the base film conveyor belt;

[0046] Figure 2 This is a side view of the wide-width dry powder film preparation apparatus of the present invention from the direction of the base film conveyor belt width;

[0047] Figure 3 This is a diagram showing the relationship between the parameters of each part of the present invention;

[0048] Wherein: 101 is the outer frame, 102 is the powder conveying pipe slide rail, 103 is the inner frame, 201 is the powder conveying pipe, 202 is the vibrating sleeve, 203 is the discharge powder clump, 204 is the reciprocating slide table, 2041 is the reciprocating slider, 2042 is the slide rail drive wheel, 205 is the distribution hopper, 206 is the combing powder layer, 207 is the rotary comb gear driver, 208 is the rotary comb gear, 209 is the brush powder blocker, 301 is the needle wheel driver, 302 is the main rotary needle wheel, 303 is the satellite rotary needle wheel, 304 is the powder clump felt, 305 is the guide needle wheel, 306 is the vibrating cleaner, 401 is the differential roller driver, 402 is the primary differential roller, 403 is the self-supporting blank, 404 is the secondary differential roller, 501 is the transport belt, 502 is the target self-supporting membrane, 503 is the electric heating plate, and 504 is the support frame. Detailed Implementation

[0049] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0050] The wide-width dry powder film preparation device of the present invention adopts a linear synchronous powder discharge mode, which overcomes the problems of uneven powder agglomerate distribution and excessively high initial film compaction density; the constant-speed powder agglomerate distribution and synchronous discharge mode of rotating needle wheel reduce the distribution deviation of powder agglomerates in both the film width and the belt travel direction; the present invention is applicable to the dispersion film formation of various protofibrillary or fibrous materials, and is particularly suitable for the production of high-precision energy storage device membranes of polymer-micron-sized fibrous or protofibrillated powder agglomerates, thus comprehensively improving the production efficiency of energy storage devices.

[0051] The polymers include one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethylene oxide (PEO), carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), polyvinylpyrrolidone (PVP), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polyacrylic acid (PAA), polyvinyl alcohol (PVA), sodium alginate (Alg), β-cyclodextrin polymer (β-CDp), and other electrochemically stable viscous fiber polymer materials.

[0052] In addition, the polymer also includes one or more additives that improve the performance of the coating layer, including conductive agents such as carbon black, porous carbon, carbon nanotubes, carbon fibers, modified graphene, conductive carbon black or micron-sized metal fibers; and electrolyte additives such as lithium bis(trifluoromethanesulfonylimide) (LiTFSI), lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), and lithium perchlorate (LiClO4).

[0053] Micron-sized solid particles include: nickel-cobalt-manganese ternary cathode materials, lithium iron phosphate-manganese iron phosphate cathode materials, silicon-carbon anode materials, solid electrolyte materials, porous carbon capacitor electrode materials, micron-sized metal particle materials, silicon carbide abrasives, silica spheres, passivated lithium powder, lithium oxide, lithium nitride, lithium oxalate, and other functional materials. The equipment of this invention exhibits good material and environmental compatibility; however, appropriate process or component parameters need to be selected based on the viscosity, particle size, and other parameters of each component powder.

[0054] like Figure 1 , Figure 2 As shown, the wide-width dry powder film preparation apparatus of the present invention is an apparatus for wide-width dispersion of solvent-free fibrillated powder agglomerates and preparation of a self-supporting film. It includes a frame assembly and, from top to bottom, a reciprocating guide discharge device, a powder agglomerate distribution device, a powder agglomerate felting device, a felting roller pressing device, and a supporting device, all mounted on the frame assembly. The reciprocating guide discharge device includes a powder conveying pipe 201 capable of reciprocating on the frame assembly. The powder agglomerate distribution device includes a distribution hopper 205 and a stirring and leveling device. The distribution hopper 205 is fixed on the frame assembly and located below the powder conveying pipe 201. The stirring and leveling device is disposed within the distribution hopper 205 to stir and level the powder agglomerates falling into the distribution hopper 205. The powder agglomerate felting device includes a main rotating needle wheel 302 and at least one satellite rotating needle wheel 303. The main rotating needle wheel 302 and the satellite rotating needle wheels 303 are rotatably mounted on the frame assembly and driven to rotate by a needle wheel power source. The main rotating needle wheel 302 is located at the distribution hopper 205. Below the hopper 205, the powder clumps in the distribution hopper 205 form powder clump felt 304 on the surface of the main rotating needle wheel 302 through the meshing main rotating needle wheel 302 and satellite rotating needle wheel 303; the felt rolling device includes multiple sets of differential roller groups arranged from top to bottom, with two differential rollers in each group rotatably mounted on the frame assembly and driven to rotate in opposite directions by the differential roller power source. The powder clump felt 304 passes between the two differential rollers in the first set of differential roller groups and is rolled into a self-supporting blank 403, and then passes between the two differential rollers in the remaining differential roller groups and is rolled into a target self-supporting film 502; the carrying device includes a conveyor belt 501 and a heating support assembly. The heating support assembly is set at the bottom of the frame assembly. The conveyor belt 501 runs from one side of the frame assembly to the other side, and is supported and heated by the heating support assembly when passing through it. The target self-supporting film 502 falls on the conveyor belt 501 and runs with the conveyor belt 501.

[0055] The frame components in this embodiment include an outer frame 101 and an inner frame 103, both of which are placed on the ground and fixed in place.

[0056] In this embodiment, a reciprocating slide 204 capable of reciprocating is provided at the middle position of the top of the outer frame 101, and the powder conveying pipe 201 is installed on the reciprocating slide 204. The reciprocating slide 204 includes a reciprocating slider 2041 and slide rail drive wheels 2042. Slide rail drive wheels 2042 are provided on both sides of the sliding direction of the reciprocating slider 2041, and two slide rail drive wheels 2042 are provided on each side. Two parallel powder conveying pipe slide rails 102 of equal height are installed on the top of the outer frame 101. There is a distance between the two powder conveying pipe slide rails 102 so that the powder conveying pipe 201 can pass through without contacting the powder conveying pipe slide rails 102. The slide rail drive wheels 2042 on both sides of the reciprocating slider 2041 roll on the powder conveying pipe slide rails 102 on both sides by the drive of the power source, thereby realizing the horizontal sliding of the powder conveying pipe 201. The power source can be a drive motor installed inside the reciprocating slider 2041, with the output shaft of the drive motor connected to the slide rail drive wheel 2042; or the power source can be a hub motor built into the slide rail drive wheel 2042, with the hub motor fixed on the reciprocating slider 2041. The power source, the installation of the power source and the connection with the slide rail drive wheel 2042 are all existing technologies and will not be described in detail here.

[0057] In this embodiment, a vibrating sleeve 202 is connected to the lower end of the powder conveying pipe 201. The vibrating sleeve 202 can vibrate the powder conveying pipe 201 back and forth (i.e., in the width direction of the outer frame 101). The vibrating sleeve 202 can be electrically or pneumatically driven, and the driving method is a commonly used solution in the machinery industry. The vibrating sleeve 202 in this embodiment is a commercially available product, purchased from Shanghai Qingwen Pneumatic Equipment Co., Ltd., and is a GT30 turbine-type small vibrating air hammer.

[0058] In this embodiment, the distribution hopper 205 is fixed at the top of the internal frame 103 and located below the powder conveying pipe 201 and the vibrating sleeve 202. The width direction of the distribution hopper 205 is consistent with the reciprocating direction of the powder conveying pipe 201. The width of the distribution hopper 205 covers the movement trajectory of the lower end of the powder conveying pipe 201 during its reciprocating motion. The powder clumps flowing out from the lower end of the powder conveying pipe 201 are received by the distribution hopper 205 and accumulate along the width direction of the distribution hopper 205.

[0059] The stirring and flattening device of this embodiment includes a rotating comb gear 208 and a rotating comb gear driver 207. The rotating comb gear driver 207 is fixed on the inner frame 103. The rotating comb gear 208 is located inside the distribution hopper 205 and above the outlet. The axial direction of the rotating comb gear 208 is consistent with the width direction of the distribution hopper 205. The axial length of the rotating comb gear 208 is greater than or equal to (here, equal to) the width of the distribution hopper 205. The output end of the rotating comb gear driver 207 is connected to the rotating comb gear 208 and drives the rotating comb gear 208 to rotate. At least one set of comb gears is embedded in the rotating shaft surface of the rotating comb gear 208 along the circumferential direction. Each comb tooth in each set is equidistant along the axial direction of the rotating shaft. Each comb tooth in each set is in full contact with the powder clumps flowing out from the lower end of the powder conveying pipe 201, stirring in the width direction of the distribution hopper 205 and flattening the powder clumps, and providing downward pressure to facilitate the discharge of the powder clumps.

[0060] In this embodiment, a detachable and replaceable brush powder blocker 209 is provided at the bottom outlet of the dispensing hopper 205. The brush powder blocker 209 includes a brush handle with brushes. The brush handle is detachably installed on the outer surface of the side wall of the dispensing hopper 205 on the side opposite to the rotation direction of the main rotating pinwheel 302. The specific installation method can be through slots or bolts, which is prior art and will not be described in detail here. The brush tip extends from the side to the bottom of the dispensing hopper 205 and overlaps with the needle part on the main rotating pinwheel 302 to prevent powder clumps from leaking out from the side. The brush powder blocker 209 in this embodiment is a commonly used non-standard mechanical accessory. Its stainless steel brush handle is 500-1000mm long × 30mm wide × 15mm wide, and the nylon bristles are 30mm long and are a two-row dense nylon long brush.

[0061] In this embodiment, the needle length on the main rotating needle wheel 302 is equal to the needle length on the satellite rotating needle wheel 303. The needle tip on the main rotating needle wheel 302 abuts against the surface of the satellite rotating needle wheel 303, and the needle tip on the satellite rotating needle wheel 303 abuts against the surface of the main rotating needle wheel 302. The needles on the main rotating needle wheel 302 and the needles on the satellite rotating needle wheel 303 alternately comb through the powder clumps brought out by the main rotating needle wheel 302.

[0062] This embodiment features three satellite rotating pinwheels 303. The first satellite rotating pinwheel 303 is located diagonally above the main rotating pinwheel 302 and on the same side as the powder discharge point. The second satellite rotating pinwheel 303 is located diagonally below the main rotating pinwheel 302 and on the same side as the powder discharge point. The third satellite rotating pinwheel 303 is located diagonally below the main rotating pinwheel 302 and on the opposite side of the powder discharge point in the distribution hopper 205. That is, the third satellite rotating pinwheel 303 is located on one side of the powder felt 304, while the first and second satellite rotating pinwheels 303 are located on the other side of the powder felt 304. The third satellite rotating pinwheel 303 acts as a guide wheel, guiding the powder felt 304 out of the rotating pinwheel assembly.

[0063] In this embodiment, both the needle surface on the main rotating needle wheel 302 and the needle surface on the satellite rotating needle wheel 303 have a barbed structure. This barbed structure is a common existing technology in the textile industry and will not be described in detail here.

[0064] In this embodiment, a vibratory cleaner 306 for cleaning the main rotating pinwheel 302 is provided on the opposite side of the powder discharge point in the distribution hopper 205. The vibratory cleaner 306 is mounted on the frame assembly, and the vibration direction is vertical. The vibratory cleaner 306 in this embodiment is a commercially available product purchased from Anhui Xiehe Brush Industry Co., Ltd., model XH-BD-3040 (304 stainless steel bracket, 40mm bristles, oscillating type). The vibratory cleaner 306 includes a vibration generator, a cleaning brush, and a negative pressure recovery pipe. The vibration generator is fixed on the internal frame 103, and the cleaning brush is embedded in the vibration generator. The vibration generator drives the vibration to achieve cleaning. One end of the main rotating pinwheel 302 is connected to the pinwheel power source, and the negative pressure recovery pipe is located at the other end of the main rotating pinwheel 302 and is mounted on the internal frame 103. Multiple sets of vibratory cleaners 306 can also be installed side by side along the width of the distribution hopper 205, cleaning synchronously in the vertical direction.

[0065] In this embodiment, the power source for the pinwheel is a pinwheel driver 301, which is mounted on the internal frame 103. The rotation shafts of one main rotating pinwheel 302 and three satellite rotating pinwheels 303 are rotatably mounted on the internal frame 103. There can be four pinwheel drivers 301, each connected to one rotating shaft; alternatively, there can be one pinwheel driver 301, connected to the four rotating shafts via a gear transmission mechanism. The gear transmission mechanism is existing technology and will not be described in detail here. The pinwheel driver 301 in this embodiment is a commercially available product, purchased from Anhui Zijin Brush Industry Co., Ltd., model B1000 / 1.1kw motor and controller.

[0066] In this embodiment, the differential roller group is divided into two groups arranged vertically. The first group of differential rollers located at the top is the primary differential roller group that initially rolls the powder felt 304. The second group of differential rollers located at the bottom is the secondary differential roller group that subsequently rolls and thins the powder felt 304. The two primary differential rollers 402 of the primary differential roller group have equal roller diameters. One of the two primary differential rollers 402 is fixed, while the other roller adjusts the roller gap width according to the different powder materials. After adjustment, it is fixed. The two secondary differential rollers 404 of the secondary differential roller group have equal roller diameters. One of the two secondary differential rollers 404 is fixed, while the other roller adjusts the roller gap width according to the different powder materials. After adjustment, it is fixed. After being rolled and stretched by two primary differential rollers 402, the powder felt 304 forms a self-supporting blank 403. The self-supporting blank 403 is then rolled and stretched by two secondary differential rollers 403 to form a target self-supporting film 502. The powder felt 304 is processed into a target self-supporting film 502 with the required thickness and porosity, and is then transferred by the conveyor belt 501 to subsequent processing or winding.

[0067] In this embodiment, the power source for the differential roller is a differential roller driver 401, which is mounted on the internal frame 103. The roller shafts of the two primary differential rollers 402 and the two secondary differential rollers 404 are rotatably mounted on the internal frame 103. There can be four differential roller drivers 401, each connected to one roller shaft; alternatively, there can be one differential roller driver 401, connected to the four roller shafts via a gear transmission mechanism. The gear transmission mechanism is existing technology and will not be described in detail here. The differential roller driver 401 in this embodiment is a non-standard customized device. The differential roller is designed to consist of at least one pair of primary differential rollers and two pairs of secondary differential rollers. The controller is integrated into the roller press control unit, allowing adjustment of the roller gap (0-5mm). It uses an oil heating mode (room temperature to 200℃, accuracy ±2%), with a pressure range of 0.5-5.0t. The roller surface is made of hard stainless steel with a hardness greater than 55HRC. This design is a common equipment type in the roller press industry.

[0068] The heating support assembly in this embodiment includes an electric heating plate 503 and a support frame 504. The support frame 504 is fixed to the bottom of the inner frame 103, and the electric heating plate 503 is installed on top of the support frame 504 for heating the conveyor belt 501. The electric heating plate 503 in this embodiment is made of stainless steel, is conductive and grounded; the support frame 504 is a height-adjustable telescopic frame.

[0069] In this embodiment, the rollers of the rotating comb gear 207, the main rotating needle wheel 302, and the satellite rotating needle wheel 303 can be made of wear-resistant metal materials, preferably stainless steel. The surface needles can be made of hard stainless steel. The needle density is selected according to the size and material of the powder. The principle is to use low-density long needles for long-fiber, low-density powder to facilitate the separation of the powder from the needles. When the powder is short-fiber, high-density, high-density short needles are used, but the needle spacing is greater than 5 to 20 times the powder D50 to avoid excessive compaction of the powder felt.

[0070] In this embodiment, the dimensions such as the reciprocating running distance of the powder conveying pipe 201, the width of the distribution hopper 205, the width of the vibrating cleaner 306, and the width of the rotating comb gear 208 are all selected according to the width of the conveyor belt 401, which is 2 to 5% wider at each end of the conveyor belt 401.

[0071] The present invention provides a wide-width dry powder film preparation method, comprising the following steps:

[0072] Step A: The output speed of the target self-supporting membrane 502 is x cm / min, the target thickness of the target self-supporting membrane 502 is y cm, the width of the target self-supporting membrane 502 is z cm, and the compaction density of the target self-supporting membrane 502 is ρ1 g / cm³. 3 Assuming the target self-supporting film 502 is stretched only along the belt direction during calendering, with a constant width, the powder output rate is k = x×y×z×ρ1g / min, the width of the distribution hopper 205 is z cm, and the powder inside the distribution hopper 205 is a compacted powder layer with a compacted density of ρ2 g / cm³. 3 The depth and cross-sectional area are a cm. 2 The powder output mass of the distribution hopper 205 is h = a×z×ρ2 g. The time required to empty the distribution hopper 205 once is t = h / k min. The time for the reciprocating guide discharge device to reciprocate once in one direction should be less than the time t min required to empty the distribution hopper 205 once (preferably 0.8t min) to maintain the synchronous descent of powder across the entire width.

[0073] Step B: The axial length of the main rotating needle wheel 302 is greater than the discharge width of the distribution hopper 205, ensuring that all the discharged powder clumps and felt 304 are carried out by the needles on the surface of the main rotating needle wheel 302. The set rotation speed of the main rotating needle wheel 302 requires that the depth of the compacted powder layer in the distribution hopper 205 remain unchanged, that is, the feeding rate and the discharge rate of the distribution hopper 205 are the same. The linear velocity of the main rotating needle wheel 302 is calculated as follows: the volume difference between the top of the two cylinders from the roller radius r to the needle length h is l = z × π × (r + h). 2 -z×π×r 2 cm 3 , using l cm 3 Subtract the volume occupied by all needles, i.e., the number of needles per square centimeter (i / cm).2 Multiply by the surface area of ​​the roller root, j cm 2 Multiply by the volume of each needle, q cm 3 This refers to the volume occupied by the powder, the ratio of the powder-covered roller surface area to the total surface area (m), the discharge volume of the fan-shaped powder discharge zone p = (li × j × q) × m mL, the actual to theoretical powder outflow ratio is w = (p / m) / l and w < 1, and the radial equivalent cross-sectional area of ​​the fan-shaped powder discharge zone is s = z × h cm. 2 The linear velocity of the main rotating pinwheel 302 is n = (p / s) / w cm / min;

[0074] Step C: The rolling temperature range of the differential roller is room temperature to 200℃ (preferably 60-150℃); the rolling speed of the slow roller in the two primary differential rollers 402 is set to n cm / min, the falling speed of the powder clump felt 304 is the same as the linear speed of the main rotating needle wheel 302, and the linear speed of the slow roller in the primary differential roller is the same as the falling speed of the powder clump felt 304, so that the powder clump felt 304 will not be squeezed at the roller gap of the primary differential roller. The rolling pressure and differential speed ratio are set according to the actual material requirements, preferably the rolling pressure is 0.5 to 5t and the differential speed ratio is 1.0 to 3.0; the linear speed of the slow roller in the two secondary differential rollers 404 is the same as the film exit speed of the upper differential roller, and the speed prediction is the roller speed of the slow roller in the primary differential roller group multiplied by the differential speed ratio, so as not to cause the target self-supporting film 502 to be squeezed at the roller gap;

[0075] Step D: Set the heating temperature of the electric heating plate 503 to room temperature to 200℃ (preferably 60-150℃) and start heating. Measure the surface temperature of the electric heating plate 503 as the set temperature. Lay the conveyor belt 501 on the electric heating plate 503, start and heat the differential roller. After reaching the set temperature, set the belt running speed to 5-30m / min and start the belt running process.

[0076] Step E: Simultaneously select a rotating comb gear 208 with a set comb tooth spacing (0.5-20mm), set the rotation speed of the rotating comb gear 208 (10-120 rpm), start the rotating comb gear 208 in the distribution hopper 205, and reach the set rotation speed;

[0077] Step F involves first drying the fiber or raw fiber granules to obtain dried powder, and then conveying the dried powder to the powder conveying pipe 201 (this is the existing powder conveying technology) through a positive and negative pressure airflow conveying system. The vibration frequency of the vibrating sleeve 202 is maintained (50-300 Hz) to ensure that the powder outflow rate is uniform and constant. The powder flows out through the powder conveying pipe 201 to the distribution hopper 205.

[0078] Step G: The powder conveying pipe 201 reciprocates at a set speed, so that the movement of the powder conveying pipe 201 is stable and there is no obvious airflow disturbance. The powder clump 203 falls into the distribution hopper 205 at a uniform speed. After the combed powder layer 206 in the distribution hopper 205 is filled to the set depth, the main rotating pinwheel 302, the satellite rotating pinwheel 303, the primary differential roller 402 and the secondary differential roller 404 are started.

[0079] Step H: Due to the different degrees of fiberization of different original fibrous powder agglomerates, the selection of rotating needle wheels with different needle lengths needs to be determined based on the fiber length. The needle lengths of the main rotating needle wheel 302 and the satellite rotating needle wheel 303 are 1.0–50.0 mm, and the material is stainless steel. The linear velocity of the main rotating needle wheel 302 is set to keep the powder agglomerate depth in the distribution hopper 205 constant, that is, the feeding rate and the discharge rate are the same. The powder inlet and outlet rates are calculated. The linear velocity of the satellite rotating needle wheel 303 is set to be the same as that of the main rotating needle wheel 302. The needles on the main rotating needle wheel 302 and the satellite rotating needle wheel 303 are interlaced and contact each other's rollers respectively. The frequency of the vibrating cleaner 306 is 10–500 Hz, and the negative pressure has no fixed range, as long as fiber recovery is achieved.

[0080] Step I: The powder clumps in the dispensing hopper 205 are discharged by rotating and meshing the main rotating pinwheel 302 and the satellite rotating pinwheel 303, and powder clump felt 304 is formed on the surface of the main rotating pinwheel 302.

[0081] Step J: The powder felt 304 is rolled between two primary differential rollers 402 to form a self-supporting blank 403, and then rolled between two secondary differential rollers 404 to form the target self-supporting film 502.

[0082] Step K, after the primary differential roller group and the secondary differential roller group roll pressing are completed, the target self-supporting film 502 can be self-supported and wound up or transported to subsequent processing or winding via the transport belt 501.

[0083] The relationship between the parameters of this invention is as follows: Figure 3 As shown.

[0084] Experimental Example 1

[0085] In this experimental example, 2.5 wt% to 7.5 wt% (2% in this case) styrene-butadiene rubber (SBR) was used as a binder, and 1.0 wt% to 5 wt% (3% in this case) carbon black C65 and 0.5 wt% to 3.5 wt% (2% in this case) fumed carbon fiber (VGCF) were used as a conductive agent to coat 85 wt% to 94.5 wt% (90.5% in this case) graphite electrode active powder as powder particles using high-shear stirring. Then, the powder particles were mixed with 0.5 wt% to 3.5 wt% (2.5% in this case) micro / nano polytetrafluoroethylene (PTFE) powder (D50 < 300 nm) and fibrillated by high-speed stirring to prepare fibrillary particles with a diameter of 5–10 mm. The specific steps for preparing a 1000 mm self-supporting membrane are as follows:

[0086] The target self-supporting membrane 502 has an output speed of 500 cm / min, a thickness of 100 μm, a width of 1000 cm, and a target compaction density of 2.0 g / cm³. 3 The powder output rate is 1000 g / min, the width of the distribution hopper 205 is 1000 cm, and the powder inside the distribution hopper 205 is a compacted powder layer with a compacted density of 1.0 g / cm³. 3 The depth cross-sectional area is 10 cm. 2 The powder output mass of the distribution hopper 205 is 1000 g. It takes t = 1 min to empty the distribution hopper 205 once. The time for the powder conveying pipe 201 to reciprocate in one direction is less than 1 min (preferably 48 s) to maintain the synchronous descent of powder across the entire width.

[0087] The axial length of the main rotating needle wheel 302 must be greater than the discharge width of the distribution hopper 205 to ensure that all the discharged powder clumps and felt 304 are carried out by the needles on the surface of the main rotating needle wheel 302. The set rotation speed of the main rotating needle wheel 302 requires that the depth of the compacted powder layer in the distribution hopper 205 remain constant, that is, the feeding rate and the discharge rate of the distribution hopper 205 are the same. The linear velocity of the main rotating needle wheel 302 is calculated as follows: the volume difference between the top two cylinders from the roller radius r = 5cm to the needle length h = 1cm is 3455.75 cm. 3 This value minus the volume occupied by all needles, i.e., the number of needles per square centimeter is 10 / cm. 2 Multiply by the surface area at the base of the roller, which is 3141.59 cm². 2 Multiply by the volume of each needle, 0.0007069 cm³. 3 That is, the surface volume between the needles is p = 3433.55 cm³. 3The actual to theoretical powder outflow ratio is w = 0.994, and the radial equivalent cross-sectional area of ​​the fan-shaped powder outflow zone is s = 100 cm². 2 The linear velocity of the main rotating needle wheel 302 is n = 10.06 cm / min, and the rotation speed of the main rotating needle wheel 302 is 0.32 rpm;

[0088] The slow roller speed of the two primary differential rollers 402 is set to 10.06 cm / min. The falling speed of the powder clump felt 304 is the same as the linear speed of the main rotating needle wheel 302. The linear speed of the slow roller in the two primary differential rollers 402 is the same as the falling speed of the powder clump felt 304, so that the powder clump felt 304 will not be crowded at the roller gap of the two primary differential rollers 402. The roller pressure and differential speed ratio are set according to the actual material requirements, preferably 0.5-5 t for the roller pressure and 1.4 for the differential speed ratio. The linear speed of the slow roller in the two secondary differential rollers 404 is the same as the film exit speed of the primary differential roller. It is estimated that the roller speed of the slow roller in the two primary differential rollers 402 multiplied by the differential speed ratio is 14.09 cm / min, so as not to cause the target self-supporting film 502 to be crowded at the roller gap.

[0089] Set the heating temperature of the electric heating plate 503 to 80℃ and start heating. Measure the surface temperature of the conveyor belt and stabilize it at the set temperature. Lay the conveyor belt 501 on the electric heating plate 503, start and heat the differential roller to 80℃. After reaching the set temperature, set the conveyor belt running speed and start the conveyor belt process.

[0090] Select a stainless steel rotary comb with a suitable tooth spacing (3.0 mm), set its speed (60 rpm), start it and reach the target speed;

[0091] The powder granules are dried to obtain dry powder material, and the powder is conveyed to the powder conveying pipe 201 (general powder conveying technology) through a positive and negative pressure airflow conveying system. The vibration frequency (110 Hz) of the vibrating sleeve 202 is maintained so that the powder outflow rate is uniform and constant.

[0092] The powder conveying pipe 201 is set to reciprocate at a fixed speed, so that the powder conveying pipe 201 runs stably without obvious airflow disturbance. The powder clumps are naturally spread into the distribution hopper 205. After the powder clump layer in the distribution hopper 205 is filled to the set depth, the main rotating pinwheel 302, the satellite rotating pinwheel 303, the primary differential roller 402 and the secondary differential roller 404 are activated.

[0093] The main rotating needle wheel 302 is set to a linear speed of 10.06 cm / min to keep the powder layer depth in the distribution hopper 205 constant, that is, the feeding rate and the discharge rate are the same. The satellite rotating needle wheel 303 is set to a linear speed that is the same as that of the main rotating needle wheel 302. The needles on the main rotating needle wheel 302 and the satellite rotating needle wheel 303 are interlaced and contact each other's rollers respectively. The vibration cleaner 306 has a frequency of 200 Hz and the negative pressure has no fixed range, as long as fiber recovery is achieved.

[0094] The thickness and compaction density of the target self-supporting film 502 are sampled and measured. Once the target requirements are met, the target self-supporting film 502 that has been rolled by the differential speed roller group can be self-supported and wound up or transported to the winding mechanism by the conveyor belt 501.

[0095] Experimental Example 2

[0096] In this embodiment, 1.5 wt% to 4.5 wt% (2% in this case) of polyvinylidene fluoride (PVDF) as a binder and 1.0 wt% to 5 wt% (2.5% in this case) of carbon black C65 and 0.5 wt% to 3.5 wt% (2% in this case) of fumed carbon fiber VGCF as a conductive agent are used as a coating layer. 87 wt% to 94.5 wt% (91.5% in this case) of graphite electrode active powder are then coated with the powder particles using high-shear stirring. The powder particles are then mixed with 0.5 wt% to 3.5 wt% (2% in this case) of micro / nano polytetrafluoroethylene (PTFE) powder (D50 < 300 nm) and fibrillated by high-speed stirring to prepare 1–3 mm diameter fibrillary agglomerates. The specific steps for preparing a 300 mm self-supporting membrane include the following:

[0097] The target self-supporting membrane 502 has an output speed of 400 cm / min, a thickness of 100 μm, a width of 50 cm, and a target compaction density of 3.5 g / cm³. 3 The powder output rate is 700 g / min, the width of the distribution hopper 205 is 50 cm, and the powder inside the distribution hopper 205 is a compacted powder layer with a compacted density of 2.5 g / cm³. 3 The depth cross-sectional area is 10 cm. 2 The powder output mass of the distribution hopper 205 is 1250 g. It takes t = 1.786 min to empty the distribution hopper 205 once. The time for the powder conveying pipe 201 to reciprocate in one direction is less than the time required to empty the distribution hopper 205 once, which is 1.786 min (preferably 108 s), so that the powder can be kept falling synchronously across the entire width.

[0098] The axial length of the main rotating needle wheel 302 must be greater than the discharge width of the distribution hopper 205 to ensure that all the discharged powder clumps and felt 304 are carried out by the needles on the surface of the main rotating needle wheel 302. The set rotation speed of the main rotating needle wheel 302 requires that the depth of the compacted powder layer in the distribution hopper 205 remain constant, that is, the feeding rate and the discharge rate of the distribution hopper 205 are the same. The linear velocity of the main rotating needle wheel 302 is calculated as follows: the volume difference between the top two cylinders from the roller radius r = 8cm to the needle length h = 0.3cm is 768.12 cm. 3 This value minus the volume occupied by all needles, i.e., the number of needles per square centimeter is 40 / cm. 2 Multiply by the surface area at the base of the roller, 2513.27 cm² 2 Multiply by the volume of each needle, 0.0002121 cm³. 3 That is, the surface volume between the needles is p = 746.80 cm³. 3 The actual to theoretical powder outflow ratio is w = 0.972, and the radial equivalent cross-sectional area of ​​the fan-shaped powder outflow zone is s = 15 cm². 2 The linear velocity of the main rotating needle wheel 302 is n = 19.20 cm / min, and the rotation speed of the main rotating needle wheel 302 is 0.38 rpm;

[0099] The slow roller speed of the two primary differential rollers 402 is set to 19.20 cm / min. The falling speed of the powder clump felt 304 is the same as the linear speed of the main rotating needle wheel 302. The linear speed of the slow roller in the two primary differential rollers 402 is the same as the falling speed of the powder clump felt 304, preventing the powder clump felt 304 from accumulating at the roller gap between the two primary differential rollers 402. The roller pressure and differential speed ratio are set according to the actual material requirements, preferably with a roller pressure of 0.5–5 t and a differential speed ratio of 1.2. The linear speed of the slow roller in the two secondary differential rollers 404 is the same as the film exit speed of the primary differential roller, estimated to be 23.04 cm / min multiplied by the differential speed ratio, to prevent the target self-supporting film 502 from accumulating at the roller gap.

[0100] Set the heating temperature of the electric heating plate 503 to 80℃ and start heating. Measure the surface temperature of the conveyor belt and stabilize it at the set temperature. Lay the conveyor belt 501 on the electric heating plate 503, start and heat the differential roller to 80℃. After reaching the set temperature, set the conveyor belt running speed and start the conveyor belt process.

[0101] Select a stainless steel rotary comb with a suitable tooth spacing (2.0 mm), set its speed (90 rpm), start it and reach the target speed;

[0102] The powder granules are dried to obtain dry powder material, and the powder is transported to the powder conveying pipe 201 (general powder conveying technology) through a positive and negative pressure airflow conveying system. The vibration frequency (200 Hz) of the vibrating sleeve 202 is maintained so that the powder outflow rate is uniform and constant.

[0103] The powder conveying pipe 201 is set to reciprocate at a fixed speed, so that the powder conveying pipe 201 runs stably without obvious airflow disturbance. The powder clumps are naturally spread into the distribution hopper 205. After the powder clump layer in the distribution hopper 205 is filled to the set depth, the main rotating pinwheel 302, the satellite rotating pinwheel 303, the primary differential roller 402 and the secondary differential roller 404 are activated.

[0104] The main rotating needle wheel 302 is set to a linear speed of 19.20 cm / min to keep the powder layer depth in the distribution hopper 205 constant, that is, the feeding rate and the discharge rate are the same. The satellite rotating needle wheel 303 is set to a linear speed that is the same as that of the main rotating needle wheel 302. The needles on the main rotating needle wheel 302 and the satellite rotating needle wheel 303 are interlaced and contact each other's rollers respectively. The vibration cleaner 306 has a frequency of 200 Hz and the negative pressure has no fixed range, as long as fiber recovery is achieved.

[0105] The thickness and compaction density of the target self-supporting film 502 are sampled and measured. Once the target requirements are met, the target self-supporting film 502 that has been rolled by the differential speed roller group can be self-supported and wound up or transported to the winding mechanism by the conveyor belt 501.

[0106] This invention combines powder feeding with wide-width dispersion using a rotating needle wheel for quantitative powder laying. It also allows for adjustment of the powder outlet width to manufacture or composite self-supporting membranes with varying width requirements. This invention overcomes the limitation of existing continuous preparation technologies where powder particles cannot be used to prepare wide-width self-supporting membranes in a loose state. It effectively improves the precision of dry-process fibrous powder membrane preparation, comprehensively enhancing the production technology level of energy storage devices. It is applicable to the dispersion and film formation of various fibrillary or fibrous materials, and is particularly suitable for the production of membrane materials for high-precision energy storage devices.

[0107] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A wide-width dry powder film preparation apparatus, characterized in that: The device includes a frame assembly and, from top to bottom, a reciprocating guide discharge device, a powder distribution device, a powder felting device, a felt rolling device, and a bearing device, all mounted on the frame assembly. The reciprocating guide discharge device includes a powder conveying pipe (201) that can slide back and forth on the frame assembly. The powder distribution device includes a distribution hopper (205) and a stirring and leveling device. The distribution hopper (205) is fixed on the frame assembly and located below the powder conveying pipe (201). The stirring and leveling device is positioned on... Inside the distribution hopper (205), the powder clumps falling into the distribution hopper (205) are stirred and flattened; the powder clump felting device includes a main rotating pinwheel (302) and at least one satellite rotating pinwheel (303), the main rotating pinwheel (302) and the satellite rotating pinwheel (303) are respectively rotatably mounted on the frame assembly and driven to rotate by a pinwheel power source, the main rotating pinwheel (302) is located below the distribution hopper (205), and the powder clumps in the distribution hopper (205) are stirred and flattened by a main rotating pinwheel (302) and at least one satellite rotating pinwheel (303). The intermeshing main rotating pinwheel (302) and satellite rotating pinwheel (303) form alum felt (304) on the surface of the main rotating pinwheel (302); the felt rolling device includes multiple sets of differential rollers arranged from top to bottom, with two differential rollers in each set rotatably mounted on the frame assembly and driven to rotate in opposite directions by a differential roller power source. The alum felt (304) passes between the two differential rollers in the first set of differential rollers and is rolled into a self-supporting blank (403), and then rolled by the remaining differential rollers. The target self-supporting membrane (502) is processed by rolling between two differential rollers in the speed roller group; the carrying device includes a conveyor belt (501) and a heating support assembly. The heating support assembly is set at the bottom of the frame assembly. The conveyor belt (501) runs from one side of the frame assembly to the other side and is supported and heated by the heating support assembly when passing through it. The target self-supporting membrane (502) falls on the conveyor belt (501) and runs with the conveyor belt (501).

2. The wide-width dry powder film preparation apparatus according to claim 1, characterized in that: The top of the frame assembly is provided with a reciprocating slide (204) that can slide back and forth, and the powder conveying pipe (201) is installed on the reciprocating slide (204); And / or, the lower end of the powder conveying pipe (201) is connected to a vibrating sleeve (202).

3. The wide-width dry powder film preparation apparatus according to claim 2, characterized in that: The reciprocating slide (204) includes a reciprocating slider (2041) and a slide rail drive wheel (2042). The reciprocating slider (2041) is provided with slide rail drive wheels (2042) on both sides of the sliding direction. The top of the frame assembly is equipped with a powder conveying pipe slide rail (102). The slide rail drive wheel (2042) rolls on the powder conveying pipe slide rail (102) driven by a power source.

4. The wide-width dry powder film preparation apparatus according to claim 1, characterized in that: The stirring and leveling device includes a rotary comb gear (208) and a rotary comb gear driver (207). The rotary comb gear driver (207) is fixed on the frame assembly. The rotary comb gear (208) is located inside the distribution hopper (205) and above the outlet. The axial direction of the rotary comb gear (208) is consistent with the width direction of the distribution hopper (205). The output end of the rotary comb gear driver (207) is connected to the rotary comb gear (208) and drives the rotary comb gear (208) to rotate. And / or, the axial length of the rotating comb gear (208) is greater than or equal to the width of the distribution hopper (205), and at least one set of comb gears is embedded in the rotating shaft surface of the rotating comb gear (208) along the circumferential direction. Each comb tooth in each set is equidistant along the axial direction of the rotating shaft. Each comb tooth in each set contacts the powder clumps flowing out from the lower end of the powder conveying pipe (201), stirs and flattens the powder clumps in the width direction of the distribution hopper (205), and provides downward pressure. And / or, the width direction of the distribution hopper (205) is consistent with the reciprocating sliding direction of the powder conveying pipe (201), the width of the distribution hopper (205) covers the movement trajectory of the lower end of the powder conveying pipe (201) during the reciprocating sliding process, and the powder clumps flowing out of the lower end of the powder conveying pipe (201) are received by the distribution hopper (205) and accumulate along the width direction of the distribution hopper (205).

5. The wide-width dry powder film preparation apparatus according to claim 1, characterized in that: A detachable and replaceable brush powder blocker (209) is provided at the bottom outlet of the distribution hopper (205). The brush powder blocker (209) includes a brush handle with a brush. The brush handle is detachably installed on the outer surface of the side wall of the distribution hopper (205) on the side opposite to the rotation direction of the main rotating needle wheel (302). The brush end extends from the side to below the distribution hopper (205) and overlaps with the needle part on the main rotating needle wheel (302) to prevent powder clumps from leaking out from the side.

6. The wide-width dry powder film preparation apparatus according to claim 1, characterized in that: The needle length on the main rotating needle wheel (302) is equal to the needle length on the satellite rotating needle wheel (303). The needle tip on the main rotating needle wheel (302) abuts against the surface of the satellite rotating needle wheel (303), and the needle tip on the satellite rotating needle wheel (303) abuts against the surface of the main rotating needle wheel (302). And / or, the needle surface on the main rotating needle wheel (302) and the needle surface on the satellite rotating needle wheel (303) both have barb structures; And / or, when there are multiple satellite rotating pinwheels (303), the last satellite rotating pinwheel (303) is located on one side of the powder clump felt (304) and on the opposite side of the powder clump discharge in the distribution hopper (205), and serves as a guide wheel for guiding the powder clump felt (304); the remaining satellite rotating pinwheels (303) are located on the other side of the powder clump felt (304) and on the same side as the powder clump discharge side in the distribution hopper (205); And / or, a vibratory cleaner (306) for cleaning the main rotating pinwheel (302) is provided on the opposite side of the powder discharge in the dispensing hopper (205), the vibratory cleaner (306) being mounted on the frame assembly; And / or, one end of the main rotating needle wheel (302) is connected to a needle wheel power source, and the other end of the main rotating needle wheel (302) is provided with a negative pressure recovery pipe installed on the frame assembly.

7. The wide-width dry powder film preparation apparatus according to claim 1, characterized in that: The differential roller group is divided into two groups arranged vertically. The first group of differential rollers located at the top is the primary differential roller group that first rolls the powder felt (304), and the second group of differential rollers located at the bottom is the secondary differential roller group that subsequently rolls and thins the powder felt (304). And / or, the two primary differential rollers (402) of the primary differential roller group have equal roller diameters, one of the two primary differential rollers (402) is fixed, and the other roller gap width is adjusted according to the different materials of the powder, and then fixed after adjustment; the two secondary differential rollers (404) of the secondary differential roller group have equal roller diameters, one of the two secondary differential rollers (404) is fixed, and the other roller gap width is adjusted according to the different materials of the powder, and then fixed after adjustment.

8. The wide-width dry powder film preparation apparatus according to claim 1, characterized in that: The heating support assembly includes an electric heating plate (503) and a support frame (504). The support frame (504) is fixed to the bottom of the frame assembly where it is placed on the ground. The electric heating plate (503) is installed on the top of the support frame (504) for heating the transport belt (501). And / or, the support frame (504) is a height-adjustable telescopic frame.

9. A method for preparing a wide-width dry powder film, characterized in that: The wide-width dry powder film preparation apparatus according to any one of claims 1 to 9 includes the following steps. Step A: Set the heating temperature of the electric heating plate (503) and start heating. Measure the surface temperature of the electric heating plate (503) to the set temperature. Lay the conveyor belt (501) on the electric heating plate (503) and start the conveyor belt process. Step B: Start the stirring and leveling device in the distribution hopper (205) to make the stirring and leveling device reach the target speed; Step C: The powder clumps are conveyed to the powder conveying pipe (201), and the powder clumps flow out through the powder conveying pipe (201) to the distribution hopper (205). Step D: The powder conveying pipe (201) reciprocates at a set speed, and the powder clumps are spread into the distribution hopper (205). The main rotating pinwheel (302), the satellite rotating pinwheel (303) and each group of differential rollers are started. Step E: The powder clumps in the dispensing hopper (205) are discharged by the rotating and meshing main rotating pinwheel (302) and satellite rotating pinwheel (303), and powder clump felt (304) is formed on the surface of the main rotating pinwheel (302). Step F, the powder felt (304) is rolled between two differential rollers in the first differential roller group to form a self-supporting blank (403), and then rolled between two differential rollers in the remaining differential roller groups to form a target self-supporting film (502). Step G: Sample and measure the thickness and compaction density of the target self-supporting film (502). The target self-supporting film (502) after being rolled by the differential roller group can achieve self-supporting winding or be transported to the winding mechanism by the carrier belt (501).

10. The method for preparing wide-width dry powder films according to claim 10, characterized in that: In step C, the powder granules are first dried to obtain dry powder, and then the dried powder is transported to the powder conveying pipe (201) through a positive and negative pressure airflow conveying system. And / or, in step C, a vibrating sleeve (202) is installed at the lower end of the powder conveying pipe (201) to maintain the vibration frequency of the vibrating sleeve (202) so that the powder flow rate in the powder conveying pipe (201) remains uniform and constant; And / or, the needle length of the main rotating needle wheel (302) and the satellite rotating needle wheel (303) is 1.0 to 50.0 mm and the material is stainless steel; the main rotating needle wheel (302) is set with a linear velocity so that the depth of the powder clump in the distribution hopper (205) remains unchanged, that is, the feeding rate and the discharge rate are the same, and the powder feeding and discharging rate is calculated; the satellite rotating needle wheel (303) is set with a linear velocity that is the same as that of the main rotating needle wheel (302), and the needles on the main rotating needle wheel (302) and the satellite rotating needle wheel (303) are interlaced and contact each other's rollers respectively; And / or, a vibrating cleaner (306) is installed on the opposite side of the powder discharge in the distribution hopper (205). The frequency of the vibrating cleaner (306) is 10 to 500 Hz, and the negative pressure has no fixed range, as long as fiber recycling is achieved. And / or, the temperature range of the differential roller is room temperature to 200℃; a primary differential roller group and a secondary differential roller group are arranged below the main rotating needle wheel (302), and the roller speed of the slower roller in the two primary differential rollers (402) in the primary differential roller group is set to n cm / min, and the falling speed of the powder felt is the same as the linear speed of the main rotating needle wheel (302), so that the powder felt (304) will not be crowded at the roller gap of the two primary differential rollers (402), and the roller pressure of the primary differential roller (402) is 0.5 to 5. t, the differential speed ratio is 1.0 to 3.0; the linear speed of the slow roller in the two secondary differential rollers (404) of the secondary differential roller group is the same as the film output speed of the upper differential roller, and the speed is the roller speed of the slow roller in the primary differential roller group multiplied by the differential speed ratio, so as not to make the self-supporting blank (403) piled up at the roller gap of the two secondary differential rollers (404); the target self-supporting film (502) after the primary differential roller group and the secondary differential roller group roll pressing can realize self-supporting winding or be transported to the winding mechanism by the conveyor belt (501).

11. The method for preparing wide-width dry powder films according to claim 10, characterized in that: The output speed of the target self-supporting membrane (502) is x cm / min, the target thickness of the target self-supporting membrane (502) is y cm, the width of the target self-supporting membrane (502) is z cm, and the compaction density of the target self-supporting membrane (502) is ρ1 g / cm³. 3 Assuming the target self-supporting film (502) is stretched only along the belt direction during calendering, with a constant width, and the powder output rate is k = x×y×z×ρ1 g / min, the width of the distribution hopper (205) is z cm, and the powder inside the distribution hopper (205) is a compacted powder layer with a compacted density of ρ2 g / cm³. 3 The depth and cross-sectional area are a cm. 2 The powder output mass of the distribution hopper (205) is h = a×z×ρ2 g. The time required for the distribution hopper (205) to be emptied once is t = h / k min. The time for the reciprocating guide discharge device to reciprocate once in one direction is less than the time t min required for the distribution hopper (205) to be emptied once, so as to maintain the synchronous descent of powder across the entire width. And / or, the axial length of the main rotating needle wheel (302) is greater than the discharge width of the distribution hopper (205), ensuring that all the discharged powder clumps and felt (304) are carried out by the needles on the surface of the main rotating needle wheel (302). The main rotating needle wheel (302) is set to a rotational speed that requires the compacted powder layer depth in the distribution hopper (205) to remain constant, that is, the feeding rate and the discharge rate of the distribution hopper (205) are the same. The linear velocity of the main rotating needle wheel (302) is calculated as follows: the volume difference between the top of the two cylinders from the roller radius r of the main rotating needle wheel (302) to the needle length h is l = z × π × (r + h). 2 - z×π×r 2 cm 3 , using l cm 3 Subtract the volume occupied by all needles, i.e., the number of needles per square centimeter (i / cm). 2 Multiply by the surface area of ​​the roller root, j cm 2 Multiply by the volume of each needle, q cm 3 This refers to the volume occupied by the powder, the ratio of the powder-covered roller surface area to the total surface area (m), the discharge volume of the fan-shaped powder discharge zone p = (li × j × q) × mmL, the actual to theoretical powder outflow ratio is w = (p / m) / l and w < 1, the radial equivalent cross-sectional area of ​​this fan-shaped powder discharge zone is s = z × h cm. 2 The linear velocity of the main rotating pinwheel (302) is n = (p / s) / w cm / min; And / or, the rolling temperature range of the differential roller is room temperature to 200℃; the rolling speed of the slow roller of the primary differential roller is set to ncm / min, the falling speed of the powder clump felt (304) is the same as the linear speed of the main rotating needle wheel (302), the linear speed of the slow roller in the primary differential roller is the same as the falling speed of the powder clump felt (304), so that the powder clump felt (304) will not be squeezed at the roller gap of the primary differential roller, and the rolling pressure and differential speed ratio are set according to the actual material requirements; the linear speed of the slow roller in the two secondary differential rollers (404) is the same as the film exit speed of the upper differential roller, and the speed prediction is the roller speed of the slow roller in the primary differential roller group multiplied by the differential speed ratio, so as not to cause the target self-supporting film (502) to be squeezed at the roller gap.

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