On-line cleaning method for the roll surface of a dry electrode film forming apparatus

Abstract

The application discloses a kind of on-line cleaning method of roll surface of dry electrode film forming equipment, comprising: by dry electrode film forming equipment, composite powder is hot-pressed into the cleaning film of preset thickness, by preparation to realize the cleaning of the roll to be cleaned of dry electrode film forming equipment while obtaining cleaning film;Wherein, during preparation, the speed of the roll to be cleaned of dry electrode film forming equipment is greater than the speed of the counter roll, the composite powder is composed of PTFE, first auxiliary material, second auxiliary material, the first auxiliary material is abrasive and / or elastic microspheres, and the second auxiliary material is low-melting-point wax phase / auxiliary agent.The application realizes on-line, mild and repeatable removal of embedded chips under the premise of maintaining the roughness and texture of the roll surface, and is suitable for various roll materials such as chromium plating and WC-Co, and various dry powder working conditions such as ternary / LFP / graphite.

Description

Technical Field

[0001] This invention relates to the field of electrochemical energy storage battery manufacturing equipment and functional materials technology, and in particular to an online cleaning method for the roller surface of a dry electrode film forming equipment. Background Technology

[0002] In the dry electrode film deposition / hot rolling process, dry electrode film deposition equipment is used to compact powders (such as high-nickel ternary, LFP, graphite / conductive carbon) into films under small roll gaps, high linear pressure, and a certain temperature. Production practice shows that when the load is high or the roll gap setting is too small, local agglomerates and hard particles are easily "embedded" on the roll surface, pressed into the micro-concavities and micropores of the chromium-plated or WC-Co roll surface; the accumulation of embedded particles will change the surface roughness parameter (Ra) and peak-valley distribution of the roll, thereby causing sheet shape fluctuations, thickness bands, and unstable interface bonding.

[0003] To address roller surface contamination, existing processes mainly employ the following methods: First, offline mechanical treatment, including light abrasion with fine sandpaper / polishing cloth, abrasive paste, or polishing wheels to remove the adhering layer; Second, wiping with solvents / oils in conjunction with non-woven fabrics, felt, or scrapers to remove floating dust and oil stains; Third, online adhesion / scraping of components, such as PU cleaning rollers, brushes, and sticky paper, to clean the surface; Fourth, blasting / physical peeling methods, such as dry ice / CO2 snow, micro-air knives, and low-pressure abrasive blasting, relying on impact and sublimation to peel off the contaminants; Fifth, special processes, such as laser cleaning or ultrasonic cleaning (which often requires roller disassembly).

[0004] The above methods are effective for removing powder and oil stains adhering to the surface, but they are often difficult to effectively remove hard particles embedded in the micro-concavities of the roller surface. At the same time, grinding / laser methods may alter the roller surface texture and coating, solvent methods may cause residual pollution and ion introduction, and online adhesive / brush methods may not achieve sufficient cleaning uniformity under wide-range and high-speed conditions.

[0005] Existing cleaning solutions often fail to achieve thorough cleaning without disassembling the rollers. Current online methods primarily involve sticky rollers / brushes / PU rollers, air knives / dry ice blasting, or solvent wiping. These methods mainly target surface debris and struggle to establish sufficient normal and tangential force fields within the roller gaps. Consequently, they are insufficient for removing ternary / carbon black particles embedded in the micro-recesses of chrome-plated or WC-Co roller surfaces. Furthermore, to protect the rollers, soft cleaning components (with lower hardness than embedded debris) are commonly used, resulting in insufficient actual contact area and micro-cutting capability. At wide widths and high speeds, rapid edge cooling and uneven load distribution lead to strip-like cleaning patterns, high residual counts, and unresolved Ra drift. Thickness / sheet defects remain along the cleaning line after cleaning.

[0006] Offline roll removal significantly impacts production efficiency. In pursuit of high cleanliness, offline polishing / grinding paste / laser treatments are often used, requiring machine shutdown, cooling, tensioning, hoisting, reassembly, alignment, and reheating. A single cycle can take several hours to multiple working days. Polishing can cause slow drift in Ra and roll crown, necessitating process re-verification after resetting, leading to secondary fluctuations in yield and thickness consistency. Frequent disassembly and reassembly increase safety and coating risks (micro-cracks, plating stripping), and cause increased consumption of work-in-process and auxiliary materials.

[0007] As dry-process electrodes develop towards higher areal density, thicker coatings, and higher speeds, the need for roller surface maintenance to shift from "downtime for repair" to "online, gentle, and repeatable" is becoming increasingly prominent. There is an urgent need for an online cleaning material and process that matches the temperature and pressure window of dry processes, which can efficiently remove embedded chips and quickly reproduce the process without disassembling the equipment or changing the Ra. Summary of the Invention

[0008] The technical problem to be solved by the embodiments of the present invention is to provide an online cleaning method for the roller surface of a dry electrode film forming equipment, so as to remove the embedded material on the roller surface of the dry electrode film forming equipment and maintain its roughness.

[0009] To address the aforementioned technical problems, this invention proposes an online cleaning method for the roller surface of a dry electrode film forming equipment, comprising: hot-pressing composite powder into a cleaning film of a preset thickness using the dry electrode film forming equipment, thereby simultaneously cleaning the roller to be cleaned in the dry electrode film forming equipment; wherein, during the preparation process, the speed of the roller to be cleaned in the dry electrode film forming equipment is greater than the speed of the counter roller, and the composite powder is composed of PTFE, a first auxiliary material, and a second auxiliary material, wherein the first auxiliary material is an abrasive and / or elastic microspheres, and the second auxiliary material is a low-melting-point wax phase / additive.

[0010] Furthermore, by using a dry electrode film forming equipment, n kinds of composite powders are sequentially hot-pressed into cleaning films of n preset thicknesses, thereby achieving n cleaning cycles of the rollers to be cleaned in the dry electrode film forming equipment, and completing the cleaning of the rollers to be cleaned in the dry electrode film forming equipment, where n is a positive integer.

[0011] Furthermore, with n=3, the three composite powders are sequentially hot-pressed into a cleaning film using a dry electrode film forming equipment, thereby achieving three cleaning cycles for the rollers to be cleaned in the dry electrode film forming equipment.

[0012] Furthermore, in the n types of composite powders during the n cleaning cycles, the Mohs hardness of the first auxiliary material decreases sequentially.

[0013] Furthermore, the particle size of the elastic microspheres in the n types of composite powders during the n cleaning processes decreases sequentially.

[0014] Furthermore, the abrasive includes one or more of Al2O3, ZrO2, talc, and CaCO3; the elastic microspheres include one or more of kaolin, glass microspheres, PMMA microspheres, and mica sheets; and the low-melting-point wax phase / additive is one or more of PE low-melting wax, PE wax, and Zn-stearate.

[0015] Furthermore, during the preparation of the cleaning membrane, the roller surface temperature of the dry electrode film forming equipment is 70 ℃, the roller pressure is 5T, the ratio of the speed of the roller to be cleaned to the speed of the counter roller is 1.1:1, and the basic linear speed is 2 m / min.

[0016] Furthermore, by mass percentage, PTFE accounts for 15%-25% of the total mass of the composite powder, the second auxiliary material accounts for 5%-10% of the total mass, and the remainder is the first auxiliary material.

[0017] Furthermore, the thickness of the cleaning film is 60 μm to 320 μm.

[0018] Furthermore, the composite powder is prepared by high-shear fibrillation of PTFE, followed by mixing with the first and second auxiliary materials.

[0019] The beneficial effects of this invention are as follows:

[0020] (1) The present invention can achieve deep cleaning without disassembling the rollers: PTFE fibrillated composite membrane works in the roller gap, and a stable tangential force field is established in the contact area through differential speed. It works in conjunction with abrasive to produce a combined effect on the embedded ternary particles, and the cleaning rate is significantly higher than that of surface adhesion / brushing. Under typical working conditions, the chip count can be reduced by ≥80% without stopping the machine to disassemble the rollers.

[0021] (2) Protecting the surface roughness and coating: The hardness of the abrasive is higher than that of the residue but lower than that of the chromium-plated or WC-Co roller material. It is supplemented with a low-melting wax phase to provide gentle adhesion and chip removal. After cleaning, the roughness drift is controlled (ΔRa≤0.02 μm), avoiding the risk of peak blunting, micro-scratches and plating stripping caused by high-energy laser / hard abrasive.

[0022] (3) Online fast and cycle friendly: the cleaning membrane of 60-120μm can be cleaned in 2-4 cycles. After cleaning, it is peeled off and wound up as a whole without changing the production formula and temperature and pressure window, significantly reducing downtime and roller change frequency, and improving yield.

[0023] (4) Measurable and controllable, easy to reproduce: The roller temperature, linear pressure, differential speed and linear speed are parameterized, and release criteria and traceability records for ΔRa, residual count and cleaning membrane contamination load (Δm / A) are established; compared with the traditional method that relies on experience-based open-loop adjustment, the cleaning effect of this invention is stable and the batch consistency is high.

[0024] (5) Compatibility and environmental friendliness: It is compatible with dry processes such as chrome plating / WC-Co rollers, ternary, LFP, graphite / silicon-based, etc. It has no strong solvents and corrosives, low ion residue, reduces secondary pollution and safety hazards to electrodes and equipment, and can be recycled. Attached Figure Description

[0025] Figure 1 These are before and after cleaning of the roller surface of the dry electrode film forming equipment according to Embodiment 1 of the present invention. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0028] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0029] The online cleaning method for the roller surface of the dry electrode film forming equipment according to the present invention includes the following steps: hot pressing composite powder into a cleaning film of a preset thickness using the dry electrode film forming equipment; simultaneously cleaning the roller to be cleaned of the dry electrode film forming equipment by preparing the cleaning film; and repeating this process to complete multiple cleanings of the roller to be cleaned.

[0030] During the preparation of the cleaning membrane, the speed of the roller to be cleaned in the dry electrode film forming equipment is greater than the speed of the opposing roller. The speed difference between the roller to be cleaned and the opposing roller creates a shearing force on the impurities on the roller surface, which has a similar "rubbing" effect, transferring the impurities.

[0031] In this invention, the prepared cleaning membrane is wound up. In specific implementation, the wound membrane can also be rolled again to remove impurities and perform secondary cleaning.

[0032] The online cleaning method for the roller surface of the dry electrode film forming equipment of this invention can solve the following technical problems: ① How to construct a controllable shear field in the roller gap under the condition of large cycle time without disassembling the rollers or stopping the production line, so as to generate an effective shearing effect on hard particles embedded in micro-concavities; ② How to match the hardness so that the cleaning medium has sufficient micro-cutting ability for residues such as NCM / carbon black, while being lower than the safety threshold of chromium-plated and WC-Co roller materials, so as to avoid micro-scratches and Ra drift; ③ How to coordinate with production parameters (roller temperature, linear pressure, roller differential speed, linear speed) to ensure in-plane consistency and reproducibility under wide-width and high-speed conditions.

[0033] The composite powder is composed of PTFE (Polytetrafluoroethylene), a first auxiliary material, and a second auxiliary material. The composite powder is prepared by high-shear fibrillation of PTFE followed by mixing with the first and second auxiliary materials. The first auxiliary material is an abrasive and / or elastic microspheres, and the second auxiliary material is a low-melting-point wax phase / additive.

[0034] This invention uses PTFE as the matrix and forms a continuous fiber network through dry high-shear fibrillation as the carrier. Abrasive / elastic microspheres (such as Al2O3, ZrO2, kaolin / glass microspheres / PMMA microspheres) are dispersed in the fiber network to achieve a composite mechanism of "cutting + rolling + ejection". A low-melting-point wax phase / additive is introduced to provide slight adhesion and chip-carrying effect at a roller temperature of 60–90℃. The composite powder is spread and hot-pressed into a cleaning film of controllable thickness. Appropriate linear pressure and differential shear are set in the cleaning zone to form a stable tangential force field at the interface between the film and the roller, thereby removing embedded chips. After cleaning, the cleaning film is peeled off and wound up as a whole, achieving one-time removal of contaminants.

[0035] In one implementation method, n kinds of composite powders are sequentially hot-pressed into cleaning films of n preset thicknesses using a dry electrode film forming equipment, thereby achieving n cleaning cycles of the rollers to be cleaned in the dry electrode film forming equipment, and completing the cleaning of the rollers to be cleaned in the dry electrode film forming equipment, where n is a positive integer.

[0036] Step 1: Spread the first composite powder and hot press it into a first cleaning film of a preset thickness using a dry electrode film forming equipment. Maintain the preset roller pressure and preset line pressure, and control the speed of the roller to be cleaned in the dry electrode film forming equipment to be greater than the speed of the roller to be cleaned. The first cleaning film is obtained, and the first cleaning of the roller to be cleaned is completed.

[0037] Step 2: Spread the second composite powder and hot press it into a second cleaning film of a preset thickness using a dry electrode film forming equipment. Maintain the preset roller pressure and preset line pressure, and control the speed of the roller to be cleaned in the dry electrode film forming equipment to be greater than the speed of the roller to be cleaned. The second cleaning film is then obtained, and the second cleaning of the roller to be cleaned is completed.

[0038] Step 3: Repeat the cleaning of the roller to be cleaned n-1 times, then spread the nth composite powder and hot press it into the nth cleaning film of the preset thickness using a dry electrode film forming equipment. Maintain the preset roller pressure and preset line pressure, and control the speed of the roller to be cleaned in the dry electrode film forming equipment to be greater than the speed of the opposing roller to obtain the nth cleaning film, thus completing the nth cleaning of the roller to be cleaned.

[0039] In n washing cycles, the Mohs hardness of the first auxiliary material in the n composite powders decreases sequentially. The particle size of the elastic microspheres in the n composite powders decreases sequentially in the n washing cycles.

[0040] Preferably, n=3, and the three composite powders are sequentially hot-pressed into a cleaning film using a dry electrode film forming equipment, thereby achieving three cleaning cycles for the rollers to be cleaned in the dry electrode film forming equipment.

[0041] In one embodiment, the abrasive includes one or more of Al2O3, ZrO2, talc, and CaCO3, the elastic microspheres include one or more of kaolin, glass microspheres, PMMA microspheres, and mica sheets, and the low-melting-point wax phase / additive is one or more of PE low-melting wax, PE wax, and Zn-stearate.

[0042] When preparing the cleaning membrane, the roller surface temperature of the dry electrode film forming equipment is 60℃–90℃ (preferably 70℃), the roller pressure is 5T, the ratio of the speed of the roller to be cleaned to the speed of the counter roller is 1.1:1, and the basic linear speed is 2 m / min.

[0043] In one implementation method, by mass percentage, PTFE accounts for 15%-25% of the total mass of the composite powder, the second auxiliary material accounts for 5%-10% of the total mass, and the remainder is the first auxiliary material.

[0044] Preferably, the cleaning film thickness is 60μm to 320μm, and more preferably 200μm. The width of the cleaning film is consistent with the width of the roller surface to be cleaned.

[0045] Example 1

[0046] Composite powder formulation 1 (wt%): PTFE micro powder (fibrillated grade) 18; Al2O3 (d50≈5 μm, Mohs≈7.8) 60; PMMA microspheres (d50≈25 μm) 15; PE low-melting wax (softening 70–85 ℃) 6; Zn-stearate 1.

[0047] Composite powder formulation 2 (wt%): PTFE 18; CaCO3 52; Kaolin (d50≈3 μm, Mohs≈4) 15; Glass microspheres (d50≈20 μm) 8; PE wax 6; Zn-stearate 1.

[0048] Composite powder formulation 3 (wt%): PTFE 22; Talc (d50≈10 μm, Mohs≈1) 50; Mica flakes (d50≈15μm, flake diameter to thickness ratio≈20:1) 20; PE wax 8.

[0049] Cleaning membrane preparation: dry high-shear fibrillation (1500 rpm × 8 min), the fiberized composite powder is evenly laid, hot roller pre-pressed to a fixed thickness, the membrane thickness after pressing is 200 μm, and the width is 300 mm.

[0050] Equipment and conditions: chrome-plated roller; roller surface temperature 70 ℃, roller pressure 5T, roller speed ratio 1.1; basic linear speed 2 m / min; cleaned 3 times according to composite powder formulations 1, 2 and 3 respectively; re-measured roller surface roughness Ra value.

[0051] The effect images of the roller surface of the dry electrode film forming equipment before and after cleaning are shown below. Figure 1 As shown.

[0052] Example 2

[0053] Composite powder formulation 1 (wt%): PTFE micro powder (fibrillated grade) 18; ZrO2 (d50≈5 μm, Mohs≈8.5) 60; PMMA microspheres (d50≈25 μm) 15; PE low-melting wax (softening 70–85 ℃) 6; Zn-stearate 1.

[0054] Composite powder formulation 2 (wt%): PTFE 18; CaCO3 52; Kaolin (d50≈3 μm, Mohs≈4) 15; Glass microspheres (d50≈20 μm) 8; PE wax 6; Zn-stearate 1.

[0055] Composite powder formulation 3 (wt%): PTFE 22; Talc (d50≈10 μm, Mohs≈1) 50; Mica flakes (d50≈15μm, flake diameter to thickness ratio≈20:1) 20; PE wax 8.

[0056] Cleaning membrane preparation: dry high-shear fibrillation (1500 rpm × 8 min), the fiberized composite powder is evenly laid, hot roller pre-pressed to fix the thickness, the membrane thickness after pressing is 200 μm, and the width is 300 mm.

[0057] Equipment and conditions: chrome-plated roller; roller surface temperature 70 ℃, roller pressure 5T, roller speed ratio 1.1; basic linear speed 2 m / min; cleaned 3 times according to composite powder formulations 1, 2 and 3 respectively; re-measured the roller surface roughness Ra value.

[0058] Example 3

[0059] Composite powder formulation 1 (wt%): PTFE micro powder (fibrillated grade) 18; ZrO2 (d50≈5 μm, Mohs≈8.5) 30; Al2O3 (d50≈5 μm, Mohs≈7.8) 30; PMMA microspheres (d50≈25 μm) 15; PE low-melting wax (softening 70–85 ℃) 6; Zn-stearate 1.

[0060] Composite powder formulation 2 (wt%): PTFE 18; CaCO3 52; Kaolin (d50≈3 μm, Mohs≈4) 15; Glass microspheres (d50≈20 μm) 8; PE wax 6; Zn-stearate 1.

[0061] Composite powder formulation 3 (wt%): PTFE 22; Talc (d50≈10 μm, Mohs≈1) 50; Mica flakes (d50≈15μm, flake diameter to thickness ratio≈20:1) 20; PE wax 8.

[0062] Cleaning membrane preparation: dry high-shear fibrillation (1500 rpm × 8 min), the fiberized composite powder is evenly laid, hot roller pre-pressed to fix the thickness, the membrane thickness after pressing is 200 μm, and the width is 300 mm.

[0063] Equipment and conditions: chrome-plated roller; roller surface temperature 70 ℃, roller pressure 5T, roller speed ratio 1.1; basic linear speed 2 m / min; cleaned 3 times according to composite powder formulations 1, 2 and 3 respectively; re-measured the roller surface roughness Ra value.

[0064] Comparative Example 1:

[0065] PTFE composite powder was not used for cleaning; only a combination of nylon brushes and air knives was used in the cleaning zone, and the cleaning time was the same as the three-cycle time for each formulation in the examples. The surface roughness Ra value of the roller was re-measured.

[0066] Equipment and conditions: Chrome-plated rollers; roller surface temperature 70 ℃, roller pressure 5T, roller speed ratio 1.1; basic linear speed 2 m / min;

[0067] To demonstrate the reliability of the test data, five sets of roughness data were tested for each set of examples and comparative examples. The roughness before roller surface treatment is shown in Table 1, and the roughness after roller surface treatment is shown in Table 2. Ra1, Ra2, Ra3, Ra4, and Ra5 in Tables 1 and 2 represent the five sets of roughness data tested, respectively.

[0068] Table 1

[0069]

[0070] Table 2

[0071]

[0072] The functional difference between this invention and the prior art lies in:

[0073] (1) The action location changes from the outer surface of the roller to a controlled shear field within the roller gap, directly acting on embedded contaminants;

[0074] (2) The decontamination method is hardness matching + differential shearing, which achieves deep cleaning without damaging the roller;

[0075] (3) Cleaning parameters are quantifiable and traceable;

[0076] (4) The maintenance mode has been changed from "shutdown and roll removal for repair" to online rapid recovery, which significantly reduces downtime losses.

[0077] This invention achieves online, gentle, and repeatable removal of embedded debris while maintaining the surface roughness and texture of the roller. It is applicable to various roller materials such as chrome plating and WC-Co, as well as various dry powder processing conditions such as ternary / LFP / graphite. It is suitable for online cleaning and maintenance of roller surfaces in dry electrode film forming / hot roll forming composite production lines.

[0078] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for online cleaning of the roller surface of a dry electrode film forming equipment, characterized in that, include: Step 1: Spread the first composite powder and hot press it into a first cleaning film of a preset thickness using a dry electrode film forming equipment. Maintain the preset roller pressure and preset line pressure, and control the speed of the roller to be cleaned in the dry electrode film forming equipment to be greater than the speed of the roller to be cleaned. The first cleaning film is obtained, and the first cleaning of the roller to be cleaned is completed. Step 2: Spread the second composite powder and hot press it into a second cleaning film of a preset thickness using a dry electrode film forming equipment. Maintain the preset roller pressure and preset line pressure, and control the speed of the roller to be cleaned in the dry electrode film forming equipment to be greater than the speed of the roller to be cleaned. The second cleaning film is then obtained, and the second cleaning of the roller to be cleaned is completed. Step 3: Repeat the cleaning of the roller to be cleaned n-1 times, then spread the nth composite powder and hot press it into the nth cleaning film of the preset thickness using a dry electrode film forming equipment. Maintain the preset roller pressure and preset line pressure, and control the speed of the roller to be cleaned in the dry electrode film forming equipment to be greater than the speed of the roller to be cleaned. The nth cleaning film is obtained, and the nth cleaning of the roller to be cleaned is completed. In the n types of composite powders that undergo n cleaning cycles, the Mohs hardness of the first auxiliary material decreases sequentially, and the particle size of the elastic microspheres in the n types of composite powders undergoes sequentially decreasing. With n=3, the three composite powders are sequentially hot-pressed into a cleaning film using a dry electrode film forming equipment, thereby achieving three cleaning cycles for the rollers to be cleaned in the dry electrode film forming equipment. In the preparation process, the speed of the roller to be cleaned in the dry electrode film forming equipment is greater than the speed of the roller. The composite powder is composed of PTFE, a first auxiliary material, and a second auxiliary material. The first auxiliary material is abrasive and / or elastic microspheres, and the second auxiliary material is a low melting point wax phase / additive. The abrasive includes one or more of Al2O3, ZrO2, talc, and CaCO3; the elastic microspheres include one or more of glass microspheres, PMMA microspheres, and mica sheets; and the low-melting-point wax phase / additive is one or more of PE low-melting wax, PE wax, and Zn-stearate. When preparing the cleaning membrane, the roller surface temperature of the dry electrode film forming equipment is 70 ℃, the roller pressure is 5T, the ratio of the speed of the roller to be cleaned to the speed of the counter roller is 1.1:1, and the basic linear speed is 2 m / min. By mass percentage, PTFE accounts for 15%-25% of the total mass of the composite powder, the second auxiliary material accounts for 5%-10% of the total mass, and the remainder is the first auxiliary material; The composite powder is prepared by high-shear fibrillation of PTFE and then mixing it with the first and second auxiliary materials.

2. The online cleaning method for the roller surface of the dry electrode film forming equipment as described in claim 1, characterized in that, In n washing cycles, the Mohs hardness of the first auxiliary material in the n types of composite powder decreases sequentially.

3. The online cleaning method for the roller surface of the dry electrode film forming equipment as described in claim 1, characterized in that, In n washing cycles, the particle size of the elastic microspheres in the n types of composite powder decreases sequentially.

4. The online cleaning method for the roller surface of the dry electrode film forming equipment as described in claim 1, characterized in that, The cleaning film thickness is 60μm to 320μm.

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