Thick Bicomponent Filter Medium for Aerosol Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional filtration media are limited in thickness, basis weight, and pore size, leading to inefficiencies in removing aerosols and particulates, and suffer from resin migration, brittleness, and early failure in demanding applications.
Innovation Solution
A filter medium comprising bicomponent fibers and glass fibers, formed through a wet-laid process, which provides a mechanically stable and adaptable structure with controlled filtration properties, allowing for thicker layers and reduced pressure drop, and incorporating additional materials for enhanced functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thin flexible filter media are used, then the media can be manufactured with standard papermaking techniques, but the filtration efficiency for aerosols and particulates is limited
Solution Approach 1:
The patent combines glass fibers with thermoplastic binder fibers to create a composite filter medium. The glass fibers provide filtration efficiency for aerosols and particulates, while the thermoplastic binder provides structural integrity and mechanical stability. This composite structure allows the medium to achieve both high filtration efficiency and manufacturability through wet-laid processes.
Solution Approach 2:
The patent changes the physical parameters of the filter medium by controlling the basis weight (50-2000 g/m²), thickness (0.5-10 mm), and fiber composition ratios. These parameter adjustments enable the medium to achieve optimal balance between filtration efficiency for large aerosols and manufacturability through standard wet-laid papermaking techniques.
2Reliability
If multiple layers of thin filter media are employed to increase filtration efficiency, then aerosol removal improves, but pressure drop increases and device complexity increases
Solution Approach 1:
Instead of stacking multiple thin layers, the patent creates a single thick filter medium with controlled thickness (0.5-10 mm) by adjusting the basis weight and fiber composition in the wet-laid process. This dimensional approach maintains filtration efficiency while reducing structural complexity and pressure drop compared to multiple layered configurations.
3Reliability
If glass fiber filter media are used, then filtration efficiency improves, but the media becomes brittle and may shatter under challenging conditions
Solution Approach 1:
The patent introduces thermoplastic binder fibers as an intermediary material between glass fibers. This binder acts as a flexible matrix that holds the rigid glass fibers together, providing mechanical strength and flexibility while maintaining the filtration efficiency of the glass fiber structure. The binder prevents brittleness and shattering under challenging conditions.
4Strength
If binder resin is applied to consolidate filter media, then structural integrity improves, but resin migration occurs during filter media life
Solution Approach 1:
The patent uses thermoplastic binder fibers that are integrated into the filter medium structure during manufacturing. These binders are designed to remain stable throughout the operational life of the filter, providing continuous structural integrity without migration. The binders are selected to match the thermal and chemical properties of the operating environment, ensuring long-term compositional stability.
5Reliability
If filter media thickness is increased to improve filtration efficiency, then aerosol removal improves, but manufacturing capability is limited to about 5.0 mm thickness
Solution Approach 1:
The patent utilizes the wet-laid papermaking process to control the thickness parameter of the filter medium, achieving thicknesses from 0.5 to 10 mm by adjusting the basis weight and fiber suspension concentration. This parameter control enables manufacturing of thicker filters for enhanced aerosol filtration while maintaining compatibility with standard papermaking equipment and processes.
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 filter medium achieves high efficiency in removing aerosols and particulates with extended lifetime, maintaining low pressure drop and burst strength, and preventing resin migration, making it suitable for various filtration applications.
Implementation Method 1
The layer is heated to a temperature such that the low melting point polymer melts, fuses and binds the layer into a mechanically stable, unitary mass
Implementation Method 2
the aerosol entrained in the fluid contacts the media, coalesces, and drains from the media leaving the mobile fluid free of the entrained liquid aerosol particulate
Implementation Method 3
The liquid accumulates in the media and under the effect of gravity, drains from the element and can be reserved
Data Source
AI summary
A filter medium for use in filtering a mobile fluid made from at least a bicomponent fiber. Other fibers, particles, or other materials can also be entrained in the filter medium. The filter medium has a substantial thickness compared to filters of the prior art. The fiber length and diameter dimensions are selected to obtain desired filter characteristics including thickness, basis weight, pore size, filtration efficiency, pressure drop, burst strength, and manufacturing efficiency. Further, a multilayer filter medium can be provided with ease. Each layer can have a different composition, pore size, basis weight, and so forth, thus providing the ability to build multiple functionality into the filter media of the invention.