Asymmetric Polyethylene Filter Membrane for Retention and Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid-flowable polyethylene filter membranes face challenges in achieving high retention with minimal flow reduction, as reducing pore size for improved retention leads to unacceptable decreases in flow rate, which is critical for high-purity liquid filtration in industrial processes like semiconductor manufacturing.
Innovation Solution
Development of an asymmetric porous polyethylene filter membrane with two sides of differing pore sizes, where one side has smaller pores for retention and the other larger pores for support, formed through an extrusion melt-cast process using specific solvent blends and controlled cooling to create an integrally asymmetric structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pore size is reduced to improve retention, then retention of contaminants is improved, but flow rate decreases to unacceptable levels
Solution Approach 1:
The membrane is designed with non-uniform pore distribution: a first region containing smaller pores for high retention and a second region containing larger pores for high flow rate. This local differentiation allows each region to optimize for its specific function, resolving the contradiction between retention and flow rate that plagues uniform membranes.
Solution Approach 2:
The membrane employs an asymmetric structure with distinct first and second regions having different pore size characteristics. This asymmetry enables the membrane to simultaneously achieve high retention (via the first region's smaller pores) and high flow rate (via the second region's larger pores), overcoming the trade-off inherent in symmetric, uniform-pore membranes.
2Reliability
If pore size is reduced to improve retention, then retention of contaminants is improved, but useful flow becomes insufficient
Solution Approach 1:
The membrane is designed with non-uniform pore distribution: a first region containing smaller pores for high retention and a second region containing larger pores for high flow rate. This local differentiation allows each region to optimize for its specific function, resolving the contradiction between retention and flow rate that plagues uniform membranes.
Solution Approach 2:
The membrane employs an asymmetric structure with distinct first and second regions having different pore size characteristics. This asymmetry enables the membrane to simultaneously achieve high retention (via the first region's smaller pores) and high flow rate (via the second region's larger pores), overcoming the trade-off inherent in symmetric, uniform-pore membranes.
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
The asymmetric membrane achieves high retention of contaminants while maintaining a useful flow rate, suitable for high-purity liquid filtration in industrial processes, with a retention of at least 90-99% and a flux of 30-100 LMH/bar, addressing the limitations of traditional membranes.
Implementation Method 1
Liquid-flowable porous filter membranes that include polyethylene and that have an asymmetric pore structure
Implementation Method 2
Filter membranes and filter products are indispensable tools of modern industry, used to remove unwanted materials from a flow of a useful fluid
Data Source
AI summary
Described are liquid-flowable, porous polyethylene filter membranes that include two opposing sides and that have an asymmetric pore structure; filter components and filters that include this type of porous polyethylene filter membrane; methods of making the porous polyethylene filter membranes, filter components, and filters; and methods of using a porous polyethylene filter membrane, filter component, or filter, to filter a fluid such as a liquid chemical to remove unwanted material from the fluid.