Low-Density Resilient Bottom Layer for Absorbent Article Integrity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing absorbent articles face challenges in achieving softness in the dry state, core integrity in both dry and wet states, and efficient liquid distribution in channels, with known ADL layers taking time to dry and exhibiting significant rewetting.

Innovation Solution

Incorporating a bottom layer with a low density and open structure between the absorbent material and the backsheet, which can be made of synthetic fibers like polyester, to reduce the amount of cellulosic fluff pulp and enhance softness, core integrity, and improve liquid distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a conventional ADL layer is used between the topsheet and absorbent core, then liquid distribution is improved, but the drying time is extended and rewetting occurs

Engineering Contradiction:

Improveliquid distributionVSAvoiddrying time

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

The patent extracts the problematic ADL layer from the conventional structure and replaces it with a bottom layer having specific properties (density 20-400 kg/m³, open structure) that performs liquid distribution without causing delayed drying or rewetting. This extraction resolves the contradiction by removing the harmful characteristics while retaining the beneficial liquid distribution function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the key parameters of the bottom layer (density between 20-400 kg/m³, open structure) to optimize its performance. By adjusting these parameters, the layer achieves efficient liquid distribution while maintaining fast drying characteristics and preventing rewetting, thus resolving the time loss issue.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If cellulosic fluff pulp is used to provide softness, then comfort is improved, but core integrity and liquid distribution efficiency deteriorate

Engineering Contradiction:

ImprovesoftnessVSAvoidcore integrity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent changes the material parameter from conventional cellulosic fluff pulp to a bottom layer with controlled density (20-400 kg/m³) and open structure. This parameter change maintains softness against the skin while significantly improving core integrity and liquid distribution efficiency, resolving the reliability issue.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite structure combining the bottom layer (with synthetic fibers providing structural integrity) and absorbent material (with superabsorbent particles). This composite approach achieves both softness and core integrity simultaneously, eliminating the trade-off between comfort and reliability.

Inventive Principle:

Principle #40Composite materials

3Quantity of substance

If absorbent material is placed throughout the channels, then absorption capacity is increased, but core integrity in wet state deteriorates

Engineering Contradiction:

Improveabsorption capacityVSAvoidcore integrity in wet state

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by placing absorbent material selectively in certain regions while leaving channels clear. The bottom layer with its open structure provides localized absorption capacity where needed, while maintaining core integrity in the channel areas. This localized approach resolves the contradiction between absorption capacity and wet state integrity.

Inventive Principle:

Principle #3Local quality

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 absorbent article achieves improved softness, reduced core sagging, and efficient liquid distribution while maintaining structural integrity, even after wetting, by utilizing a low-density bottom layer with synthetic fibers.

Implementation Method 1

a bottom layer between the absorbent material and the liquid impervious backsheet. The bottom layer is in contact with the absorbent material and has an average density between 20 and 400 kg/m3

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 2

The absorbent material comprises superabsorbent polymer particles and preferably also cellulosic fluff pulp

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP4262661B1Absorbent article with resilient bottom layer

Publication Date: 2025.10.01 DRYLOCK TECHNOLOGIES NV

Figure 1A~1C
Figure 1D~1E
Figure 2A~2C

AI summary

An absorbent article comprising a liquid pervious topsheet (300), a liquid impervious backsheet (200), absorbent material positioned between the liquid pervious topsheet and the liquid impervious backsheet, and a bottom layer between the absorbent material and the liquid impervious backsheet, wherein the absorbent material comprises superabsorbent particles and cellulosic fluff pulp and is arranged such that one or more channels are formed, wherein preferably substantially no absorbent material is present in the one or more channels, wherein the bottom layer is in contact with the absorbent material and has an average density between 20 and 400 kg/m3, preferably between 20 and 300 kg/m3, more preferably between 20 and 250 kg/m3, even more preferably between 20 and 200 kg/m3, e.g. between 20 and 120 kg/m3.