Sheet Separation Membrane Manufacturing Uniformity via Liquid Drop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing sheet-shaped separation membranes using the wet congealing method or dry-wet type congealing method often result in non-uniform separation membrane ability and surface defects due to uneven contact with the congealing liquid, leading to fluctuations in solvent concentration and polymer component concentration, which affects the membrane's performance over time.
Innovation Solution
A method involving the application of a congealing liquid using a liquid membrane drop method onto a porous substrate coated with a membrane-forming solution, ensuring uniform pressure and stable thickness, combined with a humidity adjustment step to enhance uniformity and adhesion, effectively preventing non-uniform contact and surface defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If immersion method or bottom-up contact method is used to apply congealing liquid, then the membrane can be formed, but non-uniform contact occurs leading to non-uniform separation membrane ability and surface defects
Solution Approach 1:
The patent inverts the conventional application direction by using top-down contact method where the congealing liquid is applied from above onto the membrane-forming solution coating, rather than immersing from below or contacting from the bottom. This inversion ensures uniform pressure distribution and prevents non-uniform contact, thereby achieving consistent separation membrane ability across the entire membrane surface without defects
Solution Approach 2:
The patent changes the application parameters by controlling the congealing liquid flow rate, contact pressure, and application speed to ensure uniform distribution. By adjusting these parameters, the method achieves consistent phase separation across the membrane surface, preventing local concentration variations that would lead to non-uniform separation ability and surface defects
2Manufacturing precision
If frequent exchange of congealing liquid is performed to maintain membrane quality, then separation membrane ability is improved, but waste water processing costs increase
Solution Approach 1:
The patent implements continuous application of congealing liquid in a controlled manner, ensuring consistent phase separation throughout the membrane formation process. This continuous uniform action eliminates the need for frequent liquid exchange, as the controlled application prevents concentration buildup and maintains membrane quality throughout production, thereby reducing waste water processing costs while preserving separation membrane ability
3Productivity
If higher production speed is used, then productivity increases, but uniform contact and phase separation become difficult to achieve
Solution Approach 1:
The patent employs dynamic control of the congealing liquid application system, adjusting flow rate, pressure, and contact time in real-time according to production speed. This dynamic adjustment ensures that even at higher production speeds, the congealing liquid maintains uniform contact with the membrane-forming solution, achieving consistent phase separation and uniform membrane structure throughout the membrane surface
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 enables the continuous production of sheet-shaped separation membranes with uniform separation ability and improved stability, even at higher production speeds, by ensuring uniform contact and phase separation of the membrane-forming solution, resulting in high-quality membranes with consistent performance.
Implementation Method 1
a sheet-shaped separation membrane is formed by coating a porous substrate with a membrane-forming solution in which a predetermined polymer is dissolved in a solvent, allowing a micro phase separation to be generated on the liquid membrane surface by moisture in the atmosphere while evaporating the unnecessary solvent, and thereafter immersing into a congealing liquid
Implementation Method 2
allowing a micro phase separation to be generated on the liquid membrane surface by moisture in the atmosphere while evaporating the unnecessary solvent
Data Source
AI summary
Provided is a method for manufacturing a sheet-shaped separation membrane that allows a sheet-shaped separation membrane having uniform separating ability to be manufactured at a high speed, the method comprising manufacturing a sheet-shaped separation membrane by forming a microporous layer on a porous substrate, wherein the method is characterized in having: a membrane-forming solution application step of coating a porous substrate with a membrane-forming solution in which a polymer is dissolved in a solvent, a congealing liquid application step of applying a congealing liquid by a liquid membrane drop method to the porous substrate coated with the membrane-forming solution, and a solvent removal step of removing the solvent from the congealed microporous layer.