Nonwoven Composite Fabric With Microfilament Capillarity and Open Pores

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Solution Overview

Problem

Existing capillary geotextiles exhibit poor water uptake and distribution capacity, with a risk of clogging due to their dense structure, and lack sufficient mechanical properties, especially when using microfilaments.

Innovation Solution

A nonwoven composite fabric comprising layers A and B, where layer A consists of first fibers with an average titer of at most 0.2 dtex and layer B comprises second fibers with a higher titer or woven yarns, creating a fiber titer and porosity gradient that enhances water uptake, distribution, and prevents clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If microfilaments are used to improve water uptake properties, then water uptake is improved, but the dense structure brings the risk of clogging and water accumulation

Engineering Contradiction:
Improvewater uptake capacityVSAvoidclogging risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by creating distinct layers with different fiber characteristics: layer A contains microfilaments (≤0.2 dtex) for high capillarity and water uptake at the surface, while layer B contains macrofilaments (0.25-10 dtex) for structural stability and clogging prevention in the lower portion. This spatial differentiation of fiber properties resolves the contradiction between water uptake efficiency and clogging risk.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining two different fiber types (microfilaments and macrofilaments) with significantly different linear densities in a single nonwoven structure. The composite nature allows the material to simultaneously exhibit high capillarity from microfilaments and structural openness from macrofilaments, resolving the contradiction between water uptake and clogging prevention.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the nonwoven fabric is made denser to retain particles and pollutants, then filtration is improved, but water flow through the fabric is reduced

Engineering Contradiction:
Improvefiltration capabilityVSAvoidwater flow rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by concentrating filtration functions in layer A where microfilaments create fine capillary structures for particle retention, while layer B with macrofilaments maintains open pore structures for efficient water flow. This spatial separation of filtration and flow functions resolves the contradiction between filtration capability and water flow rate.

Inventive Principle:
Principle #3Local quality

3Productivity

If microfilaments are used to enhance water distribution, then water distribution capacity is improved, but mechanical properties deteriorate

Engineering Contradiction:
Improvewater distribution capacityVSAvoidmechanical properties
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent applies local quality by assigning water distribution functions to layer A containing microfilaments, while layer B with macrofilaments provides the mechanical strength and structural integrity. This functional separation allows the composite fabric to simultaneously achieve excellent water distribution and mechanical properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining microfilaments (for water distribution) and macrofilaments (for mechanical strength) in a layered nonwoven structure. The synergistic combination allows the material to exhibit both high water distribution capacity and adequate mechanical properties, resolving the contradiction between these two characteristics.

Inventive Principle:
Principle #40Composite materials

4Speed

If the fabric grammage is reduced to improve water transport speed, then water transport is improved, but mechanical properties become insufficient

Engineering Contradiction:
Improvewater transport speedVSAvoidmechanical properties
Core Design Contradiction:
SpeedVSStrength

Solution Approach 1:

The patent applies local quality by using low grammage microfilament layer A (10-35 wt.%) for rapid water transport while combining it with macrofilament layer B (65-90 wt.%) for mechanical reinforcement. This spatial differentiation allows the fabric to achieve both fast water transport and sufficient mechanical strength despite low overall grammage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials to create a low-grammage fabric that maintains mechanical integrity. The microfilaments provide capillary action for water transport while the macrofilaments provide structural support, allowing the composite to achieve both rapid water transport and adequate mechanical properties at low grammage.

Inventive Principle:
Principle #40Composite materials

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 composite fabric achieves rapid water uptake, uniform water transport, and excellent mechanical properties, even at low grammages, while maintaining open pores to prevent clogging and retain particles.

Implementation Method 1

Capillary geotextiles can be used to pick up water from a water source such as a water reservoir, a rain collector or a water pipe and to distribute it over its surface (in plane)

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

Capillary geotextiles should have open pores that enable water to flow through. Therefore, they should not be too dense. On the other hand, capillary geotextiles should be able to retain particles and pollutants. Such filtration process helps to prevent clogging of the drainage system.

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP4506155B1Nonwoven composite fabric
Publication Date: 2025.10.29 CARL FREUDENBERG KG
  • EP4506155B1 patent drawingFigure 1
  • EP4506155B1 patent drawingFigure 2
  • EP4506155B1 patent drawingFigure 3~4

AI summary

The invention relates to a nonwoven composite fabric comprising at least one layer A and at least one layer B, wherein at least one surface layer of the nonwoven composite fabric is formed by layer A, wherein layer A is a nonwoven fabric, and wherein a) layer A comprises first fibers, preferably first filaments, being first melt-spun composite fibers, preferably first melt-spun composite filaments, which are splitted to at least some extent to produce first elementary fibers, preferably first elementary filaments, having an average titer of at most 0.2 dtex, wherein the amount of the first fibers is 10 wt.% to 35 wt.% based on the total weight of the nonwoven fabric; b) layer B comprises b1) second fibers, preferably second filaments, with an average titer from 0.25 to 10 dtex, preferably 0.25 to 3.5 dtex, wherein the amount of the second fibers is 65 wt.% to 90 wt.% based on the total weight of the nonwoven fabric, or b2) a woven grid comprising yarns having an average titer from 500 dtex to 2200 dtex, preferably from 800 dtex to 2200 dtex, wherein the amount of the yarns is 20 wt.% to 90 wt.%, preferably 65 wt.% to 90 wt.% based on the total weight of the nonwoven fabric or b3) second fibers, preferably second filaments, with an average titer from 0.25 to 10 dtex and a woven grid comprising yarns having an average titer from 500 dtex to 2200 dtex, wherein the combined amount of the second fibers and of the yarns is 65 wt.% to 90 wt.% based on the total weight of the nonwoven fabric.