Slurry Application Device with Dual Roll Adhesion Control
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Solution Overview
Problem
The challenge is to form a uniform film of slurry on a base material's surface while preventing appearance defects such as ribbing and uneven application, which occur due to vibrations during the slurry application process and changes in line speed, leading to scattering and an unsatisfactory appearance.
Innovation Solution
A slurry application device comprising a slurry supply unit, a first roll body for initial application, and a second groove attachment rubber roll for final adhesion adjustment, along with a gas ejection unit to level the surface without altering the adhesion amount, ensuring the film thickness is within one to two times of the target, and using grooves inclined at 15° to 75° to manage liquid meniscus and bubbles effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single roll applicator is used to apply slurry, then the device complexity is reduced and maintenance cost is lowered, but the manufacturing precision of uniform film formation deteriorates
Solution Approach 1:
The single roll applicator is segmented into two distinct rolls: a first roll for initial slurry application and a second roll for adhesion amount adjustment. This segmentation allows each roll to perform a specific function, with the first roll applying slurry and the second roll controlling the final adhesion amount, thereby achieving uniform film formation while maintaining relatively simple device structure.
2Manufacturing precision
If gas is ejected to adjust slurry adhesion amount, then the adhesion amount can be controlled, but the base material vibration causes nozzle position changes leading to slurry scattering and appearance defects
Solution Approach 1:
The gas ejection method is replaced with a mechanical roll applicator system. Instead of using gas flow to control adhesion amount, a second roll mechanically presses against the slurry to control the final adhesion amount. This mechanical approach eliminates the problem of nozzle position changes due to vibration, as the roll maintains constant contact pressure throughout the process.
3Ease of manufacture
If slit nozzles are used to supply slurry, then the slurry supply structure is simple, but the nozzles become clogged and uniform supply in material width direction is difficult
Solution Approach 1:
The slurry supply function is extracted from the nozzle system and transferred to the first roll applicator. Instead of using multiple nozzles to supply slurry uniformly, the first roll applies slurry in a continuous manner, eliminating the nozzle clogging problem while achieving uniform supply through the rolling motion and pressure distribution.
4Quantity of substance
If liquid meniscus amount increases between roll and base material, then more slurry is available for application, but the fluid pressure change exceeds surface tension stabilization effect causing ribbing defects
Solution Approach 1:
The operating parameters of the first and second rolls are optimized to control the liquid meniscus amount. By adjusting the pressing force, roll speed, and gap between rolls, the liquid meniscus amount is maintained within a range where surface tension stabilization is effective, preventing ribbing defects while ensuring sufficient slurry supply for application.
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
This approach ensures a uniform film is applied across the entire length of the base material, suppressing appearance defects and maintaining a beautiful appearance by minimizing liquid meniscus pressure changes and efficiently removing excess slurry, resulting in a smooth and consistent coating.
Implementation Method 1
a first roll body disposed at the downstream side in a travel direction of the base material in relation to the slurry supply unit and pressing the first roll body against the slurry supplied to the surface of the base material to apply the slurry onto the surface of the base material
Implementation Method 2
a second roll body disposed at the downstream side in the travel direction of the base material in relation to the slurry application unit and pressing the second roll body against the slurry applied on the surface of the base material to adjust the slurry adhesion amount
Implementation Method 3
a gas ejection unit configured to level an outer surface of the slurry without changing the slurry adhesion amount by ejecting a gas to the slurry
Implementation Method 4
using grooves inclined at 15° to 75° to manage liquid meniscus and bubbles effectively
Data Source
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AI summary
A slurry application device according to an aspect of the invention includes a slurry supply unit, a slurry application unit, and a slurry adhesion amount adjustment unit. The slurry supply unit supplies slurry onto a surface of a traveling base material. The slurry application unit presses a first roll body against slurry of a surface of a base material to apply the slurry onto the surface of the base material and to adjust a slurry adhesion amount such that a film thickness of the slurry of the surface of the base material becomes one time or more and two times or less of a target film thickness. The slurry adhesion amount adjustment unit presses a second roll body disposed at the downstream side in a travel direction of the base material in relation to the first roll body against the slurry of the surface of the base material to adjust the slurry adhesion amount such that the film thickness of the slurry of the surface of the base material becomes the target film thickness.