CN-121179781-B - Roll surface online cleaning method of dry electrode film forming equipment

Abstract

The invention discloses an online cleaning method for a roller surface of dry electrode film forming equipment, which comprises the steps of hot pressing composite powder into a cleaning film with preset thickness through the dry electrode film forming equipment, and cleaning a roller to be cleaned of the dry electrode film forming equipment while preparing the cleaning film, wherein the speed of the roller to be cleaned of the dry electrode film forming equipment is higher than that of a counter roller in the preparation process, the composite powder consists of PTFE, first auxiliary materials and second auxiliary materials, the first auxiliary materials are abrasive materials and/or elastic microspheres, and the second auxiliary materials are low-melting-point wax phases/auxiliary materials. On the premise of keeping the roughness and the texture of the roller surface, the invention realizes the online, mild and repeatable removal of the embedded scraps, and is suitable for various roller materials such as chrome plating, WC-Co and the like and various dry powder working conditions such as ternary/LFP/graphite and the like.

Inventors

• WANG SHICHUAN
• WANG CHEN
• LUO XUFANG
• LI XIAOLI
• LIU SHUANGSHUANG

Assignees

• 深圳清研电子科技有限公司

Dates

Publication Date

20260512

Application Date

20251125

Claims (4)

1. 1. The roll surface online cleaning method of the dry electrode film forming equipment is characterized by comprising the following steps of: Step 1, spreading the 1 st composite powder, hot-pressing the composite powder into a first cleaning film with preset thickness by adopting dry electrode film forming equipment, keeping preset roller pressure and preset line pressure, controlling the speed of a roller to be cleaned of the dry electrode film forming equipment to be greater than the speed of a counter roller, preparing the first cleaning film, and finishing the 1 st cleaning of the roller to be cleaned; Step 2, spreading the 2 nd composite powder, hot-pressing the composite powder into a second cleaning film with a preset thickness by adopting dry electrode film forming equipment, keeping preset roller pressure and preset line pressure, controlling the speed of a roller to be cleaned of the dry electrode film forming equipment to be greater than the speed of a counter roller, preparing a second cleaning film, and finishing the 2 nd cleaning of the roller to be cleaned; repeatedly cleaning a roller to be cleaned for n-1 times, spreading the n composite powder, adopting dry electrode film forming equipment to perform hot pressing to obtain an n cleaning film with preset thickness, keeping preset roller pressure and preset line pressure, controlling the speed of the roller to be cleaned of the dry electrode film forming equipment to be greater than the counter roller speed, preparing the n cleaning film, and finishing the n cleaning of the roller to be cleaned; the Mohs hardness of the first auxiliary materials in the n composite powders in the n times of cleaning is sequentially reduced, and the particle sizes of the elastic microspheres in the n composite powders in the n times of cleaning are sequentially reduced; n=3, sequentially hot-pressing the 3 composite powders into a cleaning film by using dry electrode film forming equipment, so as to realize 3 times of cleaning of a roller to be cleaned of the dry electrode film forming equipment; in the preparation process, the speed of a roller to be cleaned of dry electrode film forming equipment is larger than that of a counter roller, 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 microsphere, and the second auxiliary material is a low-melting-point wax phase/auxiliary agent; The abrasive comprises one or more of Al2O3, zrO2, talcum and CaCO 3 , the elastic microsphere comprises one or more of glass microsphere, PMMA microsphere and mica sheet, and the low-melting-point wax phase/auxiliary agent is one or more of PE low-melting wax, PE wax and Zn-stearate; When the cleaning film is prepared, 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; 15-25% of PTFE in the composite powder, 5-10% of second auxiliary material and the balance of first auxiliary material; the composite powder is prepared by high-shear fibrillation of PTFE and then mixing the first auxiliary material and the second auxiliary material.
2. 2. The online cleaning method for a roll surface of a dry electrode film forming apparatus according to claim 1, wherein the mohs hardness of the first auxiliary material in n kinds of composite powder in n times of cleaning is sequentially reduced.
3. 3. The online cleaning method for a roll surface of a dry electrode film forming apparatus according to claim 1, wherein the particle size of the elastic microspheres in n composite powders in n cleaning is sequentially reduced.
4. 4. The online cleaning method for a roll surface of a dry electrode film forming apparatus according to claim 1, wherein the cleaning film thickness is 60 μm to 320 μm.

Description

Roll surface online cleaning method of dry electrode film forming equipment Technical Field The invention relates to the technical field of electrochemical energy storage battery manufacturing equipment and functional materials, in particular to a roll surface online cleaning method of dry electrode film forming equipment. Background In the dry electrode film forming/hot rolling process, dry electrode film forming equipment is adopted, and powder (such as high nickel ternary, LFP and graphite/conductive carbon) is compacted to form a film at a small roll gap, high line pressure and a certain temperature. Production practice shows that when the load is higher or the roll gap is set smaller, local aggregates and hard particles are easy to be embedded into the roll surface of the roll and pressed into the pits and micropores of the chrome plating or WC-Co roll surface, and the embedding scraps are accumulated to change the roughness parameters (Ra) and peak-valley distribution of the roll surface, so that the sheet-shaped fluctuation and unstable combination of thickness strips and interfaces are caused. Aiming at roller surface pollution, the existing technology mainly adopts the first step of shutdown off-line mechanical treatment, which comprises fine abrasive belt/polishing cloth, grinding paste or polishing wheel light grinding to remove an adhesion layer, the second step of solvent/oil agent wiping to be matched with non-woven fabrics, felts and scrapers to take away floating ash and greasy dirt, the third step of online adhesion/scraping of components such as PU cleaning rollers, brushes and dust-binding paper to clean surfaces, the fourth step of spraying/physical stripping, such as dry ice/CO 2 snow, micro air knives and low-pressure abrasive spraying, and stripping pollution by means of impact and sublimation, and the fifth step of special technology, such as laser cleaning or ultrasonic wave (multiple-need roller disassembly). The method has a certain effect on attaching powder and greasy dirt on the surface, but hard particles embedded in the dimple of the roll surface are difficult to effectively remove, meanwhile, grinding/laser has the risks of changing the texture and the coating of the roll surface, a solvent method has hidden troubles of residual pollution and ion introduction, and on-line adhesion/brushing has insufficient cleaning uniformity under wide and high speed. In the existing cleaning scheme, the roller is not dismounted and cannot be cleaned on line. The existing online mode is mainly a dust adhering roller, a brush, a PU roller, an air knife, dry ice spraying or solvent wiping, and the mechanism of the online mode is mainly applied to surface floating scraps, and is difficult to establish enough normal compaction and tangential force fields in a roller gap, so that the stripping force of ternary/carbon black particles embedded in chromium plating or WC-Co roller surface dimple is insufficient. Meanwhile, soft cleaning pieces (hardness is lower than that of embedded scraps) are generally selected for protecting the roller, so that the real contact area and micro-cutting capability are insufficient, and when the roller is wide and high-speed, the edge is rapidly cooled, the load is uneven, the roller is cleaned on line to be in a banding mode, the residual count is high, the Ra drift is not eliminated, and the thickness/sheet-shaped defects remain along the line after cleaning. And the off-line treatment of the detaching roller seriously affects the production efficiency. In order to pursue the cleaning rate, off-line polishing/grinding paste/laser and the like are often used, and the polishing and grinding process is required to be stopped, cooled, loosened, hoisted, assembled and recovered, aligned and recovered, wherein one cycle usually lasts for several hours to several working days, the polishing and grinding process can cause the slow drifting of Ra and roller crowns, and the process is required to be re-verified after reset, so that the secondary fluctuation of the consistency of the yield and the thickness is brought. Frequent disassembly and assembly increases safety and plating risks (microcracking, deplating) and causes increased product and auxiliary material consumption. Along with the development of the dry pole piece towards high surface density, thick coating and high speed, the online, mild and repeatable requirements of roll surface maintenance are increasingly highlighted from shutdown repair, and an online cleaning material and process matched with a dry temperature-pressure window are urgently needed, so that embedded scraps can be efficiently removed and can be rapidly reproduced on the premise of not disassembling equipment and changing Ra. Disclosure of Invention The technical problem to be solved by the embodiment of the invention is to provide an online cleaning method for the roller surface of dry electrode film forming equipment so as to realize removal