Lyocell Nonwoven Webs for Liquid Distribution

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current absorbent structures in personal care products, such as diapers and feminine hygiene products, face inefficiencies in liquid distribution within the storage core layer, leading to suboptimal use of material components and structure performance.

Innovation Solution

The use of nonwoven meltblown lyocell fiber webs with superabsorbent polymers intermediate the webs, which are designed to enhance liquid distribution and retention by incorporating high hemicellulose content pulps and specific manufacturing processes like meltblown, centrifugal spinning, and spunlacing, creating a more efficient absorbent structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional absorbent structures use cellulosic fibers and wood pulp fibers in the storage core layer, then the structure provides bulk and resilience, but liquid distribution within the storage core layer is inefficient

Engineering Contradiction:

Improveliquid distribution efficiencyVSAvoidmaterial component efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the physical and chemical parameters of the fibers by using lyocell fibers with specific properties (microdiameter size, high hemicellulose content) instead of traditional wood pulp fibers. This parameter change enables more efficient liquid distribution within the storage core layer while maintaining structural integrity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite absorbent structure by combining lyocell fibers with superabsorbent polymers in a specific configuration. The lyocell fibers provide liquid distribution pathways while the superabsorbent polymers provide bulk and retention, achieving efficient liquid distribution throughout the storage core layer.

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If crosslinked cellulosic fibers are used to impart bulk and resilience, then the layer gains structural stability, but liquid wicking and distribution capability is reduced

Engineering Contradiction:

Improvebulk and resilienceVSAvoidliquid wicking capability

Core Design Contradiction:

Stability of the object's compositionVSEase of operation

Solution Approach 1:

The patent applies different properties to different parts of the absorbent structure. The lyocell fibers provide localized liquid wicking pathways, while the superabsorbent polymers provide bulk and resilience. This local differentiation allows the structure to simultaneously achieve good liquid distribution and structural stability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The lyocell fibers act as an intermediary between the liquid source and the superabsorbent polymers. They conduct liquid through the storage core layer to the superabsorbent polymers, enabling efficient liquid distribution while the superabsorbent polymers maintain bulk and structural stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If high quality wood pulps are extensively processed to remove non-cellulose components to produce lyocell fibers, then fiber quality for nonwoven applications is improved, but production cost significantly increases

Engineering Contradiction:

Improvefiber quality and bonding capabilityVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the raw material parameters by using pulp with high hemicellulose content instead of extensively processed high alpha pulps. The hemicellulose content is maintained at 3-18% to provide interfiber bonding, eliminating the need for expensive extensive processing while maintaining fiber quality for nonwoven applications.

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

This configuration improves liquid distribution and retention within the absorbent structure, leading to better performance and material efficiency, with enhanced absorbency and integrity, as demonstrated by improved liquid distribution and rewet performance compared to traditional products.

Implementation Method 1

superabsorbent intermediate (i.e. between) the two nonwoven meltblown lyocell fiber webs which can be used as a storage core layer in a hygienic product

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

Fibers made from pulp with a high hemicellulose content are particularly suited for this application because of the added interfiber bonding attributed to hemicellulose

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS8012565B2Lyocell nonwoven webs

Publication Date: 2011.09.06 GCF US HOLDINGS LLC

AI summary

Absorbent structures with nonwoven meltblown lyocell fiber webs are described which have excellent liquid distribution properties. The absorbent structures comprise at least two nonwoven meltblown lyocell fiber webs with superabsorbent polymer intermediate the two webs. Methods for making the structures are also described. The structures are particularly useful for use in disposable hygienic products.