How to Control the Uniformity of Lithium Battery Coating?
Jul 18, 2024
Controlling the uniformity of lithium battery coating involves multiple factors across various aspects such as personnel, machinery, materials, methods, and environment. However, the fundamental factors are directly related to the coating process conditions, including the coating substrate, adhesive, coating steel roller/rubber roller, and the laminating machine. 1. Coating Substrate: Key factors are the material type, surface properties, thickness, and its uniformity. 2. Adhesive: Main considerations are its working viscosity, affinity, and adhesion to the substrate surface. 3. Coating Steel Roller: As the direct carrier of the adhesive and the supporting benchmark for the coating substrate and rubber roller, it is the core of the entire coating mechanism. Factors like geometric tolerance, rigidity, dynamic and static balance quality, surface quality, temperature uniformity, and heat deformation affect coating uniformity. 4. Coating Rubber Roller: The rubber roller is an essential variable for coating quality. Its material (e.g., durability of the rubber layer), hardness, geometric tolerance, rigidity, dynamic and static balance quality, surface quality, and heat deformation also influence coating uniformity. 5. Laminating Machine: It serves as the foundational platform for coating. In addition to the precision and sensitivity of the coating steel roller and rubber roller pressing mechanism, it also encompasses the design operating speed and overall machine stability. The influencing factors for coating uniformity differ in the lateral and longitudinal directions, necessitating different control measures. These measures relate to both the design and manufacturing of the machine, as well as operational and process control. In practice, ensuring uniform coating involves both technical adjustments to the machinery and precise operational procedures. Lateral Uniformity of Coating and Its Control The uniformity of coating in the width direction is primarily influenced by the following factors: Geometric tolerance of steel rollers and rubber rollers. Contact pressure between steel rollers and the substrate. Lateral distribution of the adhesive, primarily referring to the viscosity of the adhesive and its corresponding transfer rate. This is comprehensively determined by the first two factors and the working viscosity of the adhesive. The primary benchmark for ensuring coating accuracy is the geometric tolerance and rigidity of the steel roller. During operation, the geometric tolerance, rigidity, balance precision, assembly precision, and built-in heating and insulation system of the steel roller directly affect the state of the adhesive, thereby influencing the transfer rate and coating uniformity. Therefore, designing and selecting high-precision, wear-resistant steel rollers is a fundamental task. Rubber rollers, especially the coating...