Slurry Spray Angle and Position Control for Particle Adhesion
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Solution Overview
Problem
Existing methods for applying slurry using a roll coater fail to effectively suppress the adhesion of coarse particles to the substrate, leading to uneven coating and defects, particularly at slower substrate conveyance speeds.
Innovation Solution
Controlling the spray angle, slurry supply position, and flow rate to enhance the flow of particles and prevent adhesion, with specific ranges for spray angle (5° to 50°), distance (100 mm or less), and flow rate (35 L/min/m or more) to ensure uniform coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a slurry is applied using a squeeze coater in a horizontal pass, then the coating process is simple, but coarse particles adhere to the substrate surface causing defects
Solution Approach 1:
The substrate is preliminarily treated by spraying water or slurry before the squeeze coating process. This preliminary action creates a liquid layer that prevents coarse particles from directly adhering to the substrate surface during the squeezing process, thereby resolving the particle adhesion problem while maintaining process simplicity
Solution Approach 2:
A liquid intermediary (water or slurry spray) is introduced between the substrate and coarse particles. This intermediary layer acts as a barrier that prevents direct contact and adhesion between coarse particles and the substrate surface, eliminating coating defects while keeping the overall process simple
2Manufacturing precision
If the substrate conveyance speed is reduced to 40 m/min or less, then the coating quality can be improved, but the flow that winds up particles becomes weak allowing particle adhesion
Solution Approach 1:
A liquid intermediary spray is applied to the substrate before coating. This intermediary layer maintains particle suppression effectiveness even at reduced conveyance speeds by providing a liquid barrier that prevents particle adhesion, decoupling coating quality from conveyance speed dependencies
Solution Approach 2:
The process parameters are changed by introducing a liquid spray regime that alters the particle-substrate interaction mechanism. This parameter change enables effective particle suppression at lower conveyance speeds by changing from reliance on flow-induced particle removal to liquid-barrier-based prevention
3Manufacturing precision
If multiple spray nozzles are used to apply slurry, then the application amount can be controlled, but coarse particles still adhere to the substrate
Solution Approach 1:
A preliminary spray of water or slurry is applied before the main slurry application. This preliminary action creates a protective liquid layer on the substrate that prevents coarse particles from adhering during subsequent coating operations, maintaining both application uniformity and particle suppression
Solution Approach 2:
An intermediary liquid layer is introduced between the multiple spray nozzles and the substrate surface. This intermediary layer allows controlled slurry application while simultaneously preventing coarse particle adhesion by acting as a barrier that reduces direct particle-substrate contact
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively suppresses the adhesion of large particles to the substrate, reducing coating defects and improving surface quality, especially at slower speeds where particle adhesion is more pronounced.
Implementation Method 1
a slurry is sprayed from a nozzle onto a strip member in a traveling state
Data Source
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AI summary
Adhesion of particles having a large particle size contained in the slurry to a surface of a strip member is suppressed. A slurry application method includes: spraying a slurry from a nozzle onto one or both of a traveling strip member and a roll; and applying the slurry to a surface of the strip member by pressing the roll against the surface of the strip member, wherein an spray angle θ defined as an angle between a plane horizontal to the strip member and the spray direction of the nozzle is set to 0° or more and 50° or less, a distance d in a conveyance direction of the strip member between an intersection point PI and a rotation center P2 of the roll is 100 mm or less, the intersection point PI being closest to the nozzle among an intersection point between a straight line extending in an spray direction of the nozzle and the surface of the strip member and an intersection point between the straight line extending in the spray direction of the nozzle and a surface of the roll, and a height h from the surface of the strip member to the intersection point PI is 1/2 or less of a diameter of the roll.