Trilobal Fiber Absorption Layer for Hygiene Rewetting

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Solution Overview

Problem

Hygiene products, such as diapers and sanitary napkins, face issues with rewetting, where absorbed liquid is released back to the skin, causing discomfort and skin irritation, and existing absorption and distribution layers struggle to balance absorption capacity, distribution, and rewetting while maintaining thinness and comfort.

Innovation Solution

A receiving and distribution layer composed of trilobal fibers, which are spunbond nonwovens, designed to minimize rewetting by using a hydrophilic finish and specific fiber geometry, allowing for efficient liquid absorption and distribution without fluid backlash, even under pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fluid-permeable top layer is used to ensure softness and comfortable feel on the skin, then the wearing comfort is improved, but the overall thickness of the hygiene product increases

Engineering Contradiction:
Improvewearing comfortVSAvoidthickness
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The patent combines the functions of the top layer and absorption/distribution layer into a single integrated layer. The nonwoven fabric is designed with dual functionality: the outer surface provides softness and skin comfort (top layer function), while the inner structure with hydrophilic fibers and capillary channels enables rapid liquid absorption and distribution (absorption layer function). This merging eliminates the need for a separate fluid-permeable top layer, thereby reducing overall thickness while maintaining wearing comfort.

Inventive Principle:
Principle #5Merging (Combining)

2Quantity of substance

If modern absorbent cores with superabsorbents are used to retain large portions of liquid, then the absorption capacity is improved, but the absorbent core feels damp and causes rewetting

Engineering Contradiction:
Improveabsorption capacityVSAvoidrewetting
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a nonwoven fabric layer as an intermediary between the absorbent core and the user's skin. This layer acts as a mediator that rapidly absorbs and distributes liquid away from the skin surface through capillary action in its three-dimensional structure, preventing liquid from the damp absorbent core from rewetting the skin. The hydrophilic fibers and controlled pore structure enable this intermediary function, effectively decoupling the high absorption capacity of the core from the dampness problem.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Length of stationary object

If the hygiene product is made thinner to reduce discomfort and improve wearing comfort, then the wearing comfort is improved, but the absorption capacity and distribution efficiency may be reduced

Engineering Contradiction:
ImprovethicknessVSAvoidabsorption capacity
Core Design Contradiction:
Length of stationary objectVSQuantity of substance

Solution Approach 1:

The patent changes the structural parameters of the nonwoven fabric to achieve high absorption capacity in a thin profile. Key parameter changes include: using fine hydrophilic fibers (1-10 dtex) to increase surface area for absorption, creating a three-dimensional network structure with controlled pore size (10-100 micrometers) to enhance capillary action, and optimizing fiber arrangement to maximize liquid distribution efficiency. These parameter changes enable the thin layer to maintain high absorption and distribution performance despite reduced thickness.

Inventive Principle:
Principle #35Parameter changes

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 trilobal fiber-based layer effectively absorbs and distributes liquids quickly while preventing rewetting, ensuring comfortable wear and reducing skin irritation, with improved mechanical and optical properties, and lower material costs.

Implementation Method 1

a receiving and distribution layer for a liquid to be received, comprising at least one nonwoven fabric made of trilobal fibers

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

designed to minimize rewetting by using a hydrophilic finish and specific fiber geometry

Methodology Applied
Scientific EffectHydrophilic effect: Hydrophile

Data Source

PatentEP3177252B1Absorbing and distributing layer for a liquid to be absorbed and products produced therefrom
Publication Date: 2023.06.07 FITESA GERMANY GMBH
  • EP3177252B1 patent drawingFigure 1
  • EP3177252B1 patent drawingFigure 2
  • EP3177252B1 patent drawingFigure 3a~3b

AI summary

The present invention relates to an absorbing and distributing layer for a liquid to be absorbed, to a sheet material at least comprising a corresponding absorbing and distributing layer, to a hygiene article at least comprising a corresponding absorbing and distributing layer, to a method for producing a corresponding sheet material, and to the use of the corresponding absorbing and distributing layer.