Thermal Needling Filter Medium for Small Particle Separation
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Solution Overview
Problem
Existing air filters for internal combustion engines face challenges in efficiently purifying large volume air flows without using split fibers, which are costly and complex to produce due to the needling process, leading to inefficiencies in small particle separation.
Innovation Solution
A filter medium composed of a spunbonded nonwoven layer with synthetic polymer fibers, compacted by calendering, and a further spunbonded layer with a fiber diameter gradient, joined by mechanical needling and treated with a heated surface to reduce needle holes, eliminating the need for split fibers and complex water jet needling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If water jet needling is used to consolidate filter media, then consolidation is achieved, but needle holes are formed on the clean air side which reduce filter efficiency for small particles
Solution Approach 1:
The patent replaces water jet needling with thermal needling using heated needles. This substitution eliminates the formation of large needle holes on the clean air side while still achieving proper consolidation of the filter media layers, thereby maintaining consolidation strength while improving filter efficiency for small particles.
Solution Approach 2:
The patent changes the consolidation method from mechanical water jet needling to thermal needling with heated needles at controlled temperatures. This parameter change allows consolidation to be achieved without creating harmful needle holes, thus resolving the contradiction between consolidation strength and filter efficiency.
2Reliability
If split fibres are used to ensure sufficient separation of small particles, then separation efficiency improves, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts the requirement for split fibres from the filter media design. By using thermal needling consolidation, the patent achieves high separation efficiency for small particles without needing to incorporate complex split fibre structures, thereby eliminating manufacturing complexity while maintaining separation efficiency.
Solution Approach 2:
The patent uses standard fibres instead of expensive split fibres, achieving comparable or better performance through the thermal needling process. This simplifies manufacturing and reduces costs while maintaining high separation efficiency.
3Ease of manufacture
If standard fibres are used instead of split fibres, then manufacturing is simpler, but separation efficiency for small particles decreases
Solution Approach 1:
The patent replaces mechanical water jet needling with thermal needling, which creates smaller, less harmful needle holes. This allows standard fibres to achieve high separation efficiency that would otherwise require complex split fibre structures, thus maintaining manufacturing simplicity while improving separation efficiency.
Solution Approach 2:
By changing from water jet needling to thermal needling with controlled temperature and needle geometry, the patent enables standard fibres to achieve high separation efficiency, resolving the contradiction between manufacturing simplicity and separation performance.
4Strength
If needle density is increased to improve consolidation, then consolidation strength increases, but needle holes on outer side increase reducing filter performance
Solution Approach 1:
The patent substitutes water jet needling with thermal needling using heated needles. This creates smaller, less harmful needle holes that do not significantly impact filter performance even at higher needle densities, allowing strong consolidation without sacrificing filter performance.
Solution Approach 2:
By changing to thermal needling with heated needles at optimized temperatures and adjusting needle geometry, the patent achieves strong consolidation with minimal impact on filter performance, resolving the contradiction between consolidation strength and filter performance.
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 separation efficiency for small particles (>99.8%) with reduced needle holes on the outer side, ensuring effective air filtration without split fibers and complex production methods, while maintaining moderate dust capacity and air permeability.
Implementation Method 1
the diameter of the holes formed on the outer side of the textile nonwoven layer (layer 1) which faces away from the first textile nonwoven layer (layer 2) is reduced by means of action of a heated surface, preferably a calender, by at least 50%, preferably by at least 80%
Implementation Method 2
the textile nonwoven layer (layer 1) and the further textile nonwoven layer (layer 2) are joined to one another by mechanical needling
Implementation Method 3
the textile nonwoven layer (layer 1), preferably the spunbonded nonwoven layer, was preferably compacted by means of a calendering to an air permeability of 500-2000 l/m2 sec
Data Source
AI summary
The present invention relates to a filter medium, a method for the manufacture thereof and the use of the filter medium according to the invention. The filter medium according to the invention comprises at least two textile nonwoven layers which are joined to one another by needling. The needled composite is then subjected to an after treatment so that the holes present from the needling are reduced by at least 50%.