Stitch-Bonded Elastomeric Nonwoven for Wound Dressing Absorbency

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Solution Overview

Problem

Conventional wound dressings lack extensibility and recovery due to the incorporation methods of superabsorbent particles or fibers, which limits their stretchability and absorbency, necessitating thinner or smaller absorbent components with reduced absorbency.

Innovation Solution

A stitch-bonded nonwoven substrate with an elastomeric yarn blend of superabsorbent and non-superabsorbent materials, providing both high stretchability and absorbency, utilizing materials like spandex and crosslinked polyacrylates, and incorporating superabsorbent fibers to enhance absorbency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If superabsorbent particles or fibers are conventionally incorporated into the absorbent component, then absorbency capacity is improved, but stretchability and extensibility recovery deteriorate

Engineering Contradiction:
Improveabsorbency capacityVSAvoidstretchability
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent applies composite materials by combining superabsorbent fibers with elastomeric fibers in a blended nonwoven structure. The superabsorbent fibers (e.g., cellulose-based) provide absorbency capacity while the elastomeric fibers (e.g., polyurethane, polyester) provide stretchability and elasticity. This composite approach allows the absorbent component to simultaneously achieve high absorbency and extensibility recovery, resolving the technical contradiction between these two properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the physical and chemical parameters of the absorbent component by incorporating elastomeric materials that can reversibly deform. The elastomeric fibers undergo elastic deformation when stretched and return to their original configuration, enabling the fabric to recover its shape. This parameter change in the material composition allows the absorbent component to maintain both high absorbency capacity and improved stretchability with excellent recovery properties.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the absorbent component is made thinner or smaller to improve stretchability, then extensibility recovery is improved, but absorbency deteriorates

Engineering Contradiction:
Improveextensibility recoveryVSAvoidabsorbency
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent uses composite materials where elastomeric fibers are integrated with superabsorbent fibers. The elastomeric component provides the necessary stretch and recovery properties even when the overall fabric thickness is reduced, while the superabsorbent fibers maintain high absorbency capacity. This allows the absorbent component to be thinner yet still achieve both good extensibility recovery and high absorbency.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by having different regions or aspects of the nonwoven fabric serve different functions. The elastomeric fibers are distributed throughout the structure to provide stretch and recovery properties, while the superabsorbent fibers are positioned to maximize absorbency capacity. This local differentiation allows the fabric to achieve both extensibility recovery and high absorbency without requiring increased thickness.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If conventional absorbent materials are used, then absorbency is improved, but device complexity increases due to additional stitching requirements

Engineering Contradiction:
ImproveabsorbencyVSAvoidstitching requirements
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent merges the functions of the absorbent component and the elastic component into a single integrated nonwoven fabric structure. By blending superabsorbent fibers with elastomeric fibers in one fabric layer, the invention eliminates the need for separate stitching operations to attach elastic elements to the absorbent component. This integration reduces device complexity while maintaining high absorbency properties.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The nonwoven fabric serves multiple functions simultaneously: it provides absorbency through the superabsorbent fibers, elasticity through the elastomeric fibers, and structural integrity as a single integrated layer. This multi-functionality reduces the need for additional components and stitching operations, thereby reducing device complexity while maintaining high absorbency capacity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution enables the creation of absorbent components that are both stretchable and highly absorbent, improving wound dressing performance by maintaining absorbency while allowing for increased extensibility and recovery.

Implementation Method 1

Elastomeric materials are materials that possess high elongations (10%-800%) prior to breaking and that recover fully and rapidly from high elongations up to their breaking point.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the nonwoven substrate comprises a a blend of superabsorbent material and/or a gelling material and non-superabsorbent and non-gelling support material(s)

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP4017449B1Absorbent component
Publication Date: 2024.11.20 T J SMITH & NEPHEW
  • EP4017449B1 patent drawingFigure 1
  • EP4017449B1 patent drawingFigure 2~3A
  • EP4017449B1 patent drawingFigure 3B~4B

AI summary

An absorbent component for a wound dressing comprises a stitch bonded nonwoven substrate wherein the nonwoven substrate is stitch bonded with an elastomeric yarn and wherein the nonwoven substrate comprises a superabsorbent material and/or a gelling material. Also disclosed is a method of manufacturing the absorbent component, a wound dressing or a negative pressure apparatus comprising the absorbent component and a method of treating a wound using said wound dressing or negative pressure apparatus comprising the absorbent component.