Nanofiber Filter Material With Bonded Layers for Compact Air Filtration

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Solution Overview

Problem

Existing air filtration systems require additional installation space due to the need for a separate pleated pre-filter layer, which compromises the compactness of the filter element and reduces the stability of filtration efficiency over time.

Innovation Solution

A filter material with a cohesive connection of a pre-filter layer, an activated carbon layer, and a composite layer with nanofibers, where the composite layer is designed as a fine filter medium with EPA properties, and the layers are laminated together using methods like gluing or ultrasonic welding, allowing for a more compact and stable filtration system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate pleated pre-filter layer is used, then dust filtration is achieved, but installation space increases and filter element compactness decreases

Engineering Contradiction:
Improvedust filtrationVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent combines the pre-filter layer, activated carbon layer, and fine filter layer with nanofibers into a single integrated filter material structure. The layers are bonded together to form one cohesive unit, eliminating the need for separate pleated pre-filter components and reducing overall installation space while maintaining dust filtration functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention uses a composite structure consisting of multiple functional layers (pre-filter, activated carbon, nanofiber fine filter) bonded together. This composite material approach allows different filtration functions to be integrated in a single compact element, achieving dust filtration without increasing installation space.

Inventive Principle:
Principle #40Composite materials

2Reliability

If layers are co-pleated together, then filtration is achieved, but mechanical stability and temperature stability decrease

Engineering Contradiction:
Improvefiltration functionVSAvoidmechanical stability and temperature stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent replaces the mechanical co-pleating connection system with a chemical bonding system using adhesives. The layers are bonded together through adhesive bonding, thermal compression, or ultrasonic welding, providing superior mechanical stability and temperature stability compared to mechanical folding connections.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention introduces adhesive materials as intermediaries to bond the pre-filter layer, activated carbon layer, and nanofiber composite layer together. This intermediary bonding mechanism provides stronger and more stable connections than direct mechanical co-pleating, enhancing both mechanical and temperature stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If multiple layers are pleated separately, then filtration is achieved, but device complexity and installation space increase

Engineering Contradiction:
Improvefiltration performanceVSAvoidfilter element structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple separate filtration layers into a single bonded composite structure. The pre-filter layer, activated carbon layer, and nanofiber fine filter layer are laminated together as one unit, simplifying the overall device structure and reducing installation space requirements while maintaining comprehensive filtration performance.

Inventive Principle:
Principle #5Merging (Combining)

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 cohesive connection enhances mechanical stability and temperature stability, maintaining high filtration efficiency with reduced pressure loss and energy requirements, while the nanofibers provide improved filtration performance and longer lifespan without increasing installation space.

Implementation Method 1

The advantage of nanofibers compared to thicker fibers is that they have a larger surface area, enabling improved filtration performance and a longer filter lifespan. The high interception effect, due to their small fiber diameters, is particularly beneficial.

Methodology Applied
Scientific EffectInterception:

Implementation Method 2

The advantage of nanofibers compared to thicker fibers is that they have a larger surface area, enabling improved filtration performance and a longer filter lifespan. The high interception effect, due to their small fiber diameters, is particularly beneficial.

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 3

an activated carbon layer as an adsorption layer

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 4

The bonded connection can be achieved through any type of lamination or lamination, by means of adhesive bonding (polymer threads, powder, M-Web, reactive or thermal adhesive such as thermoplastic hot melt, etc.)

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Implementation Method 5

The bonded connection can be achieved through any type of lamination or lamination, by means of adhesive bonding (polymer threads, powder, M-Web, reactive or thermal adhesive such as thermoplastic hot melt, etc.), thermal compression (calendering with/without melt fiber components)

Methodology Applied
Scientific EffectThermal compression: Compression

Implementation Method 6

The bonded connection can be achieved through any type of lamination or lamination, by means of adhesive bonding (polymer threads, powder, M-Web, reactive or thermal adhesive such as thermoplastic hot melt, etc.), thermal compression (calendering with/without melt fiber components), or by means of ultrasonic welding or calendering.

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentEP4442348A1Filter material comprising a nanofiber layer and filter element made of such filter material
Publication Date: 2024.10.09 CARL FREUDENBERG KG
  • EP4442348A1 patent drawingFigure 1~2
  • EP4442348A1 patent drawingFigure 3~4
  • EP4442348A1 patent drawingFigure 5

AI summary

The invention relates to a filter material (10) for air filtration in a filter element (100) and a filter element made of such filter material. The filter material (10) is equipped with a pre-filter layer (2) on the upstream side, an activated carbon layer (3), and a composite layer (1) which is designed as a fine filter layer with nanofibers. According to the invention, the layers are bonded together. Thanks to the combination of the pre-filter layer and the composite layer with nanofibers in one filter material, a high dust holding capacity is advantageously achieved simultaneously with a high quality factor.