Absorbent Core Channels with Varying Bond Strength for Fluid Flow

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Solution Overview

Problem

Existing absorbent articles with channels in the core face challenges such as reduced fluid absorption kinetics and effective capacity, particularly in the crotch region, due to constraints imposed by channel bonding, leading to potential leakage and inefficient use of absorbent material.

Innovation Solution

The absorbent core features a channel with varying bond strength along its length, with a weaker bond in the intermediate section to allow delamination and release of swelling pressure, while maintaining stronger bonds in the front and crotch sections, enhancing fluid handling and reducing leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the channel bond strength is increased to improve durability against delamination pressure, then the channel structural integrity is improved, but the fluid absorption kinetics and effective capacity are reduced

Engineering Contradiction:
Improvechannel bond strengthVSAvoidfluid absorption kinetics
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent applies local quality by creating different bond strengths in different sections of the channel. The front section (within 10% of front end) and crotch section (within 10% of back end) have strong bonding to maintain structural integrity, while the intermediate section has reduced bond strength to allow controlled delamination. This local differentiation resolves the contradiction by providing strength where needed and flexibility where fluid absorption is prioritized.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The channel is segmented into three distinct bonding zones: front section, intermediate section, and crotch section. Each zone has different bond strength characteristics. The segmentation allows the channel to simultaneously provide structural support in critical areas while enabling fluid access and absorption in the intermediate section, thus resolving the contradiction between strength and absorption kinetics.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the channel bond strength is increased to prevent delamination, then the channel durability is improved, but the liquid distribution and wet fit are compromised

Engineering Contradiction:
Improvechannel durabilityVSAvoidliquid distribution
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The bonding pattern applies local quality by concentrating strong bonds at the channel ends (front and crotch sections) where structural support is critical for durability, while reducing bond strength in the intermediate section to enable liquid distribution through controlled delamination. This resolves the contradiction between reliability and ease of operation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The bonding structure is pre-designed with weaker intermediate sections before use, allowing the channel to automatically delaminate in the intermediate zone when exposed to liquid. This preliminary action enables liquid distribution without requiring external intervention, while the strong end sections maintain channel durability.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If uniform bond strength is applied throughout the channel, then the manufacturing process is simplified, but the absorbent material usage efficiency is reduced

Engineering Contradiction:
Improvebonding process simplicityVSAvoidabsorbent material usage efficiency
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The bonding process uses local quality by applying different bond strengths to different channel sections. The front and crotch sections receive strong bonding to prevent delamination, while the intermediate section receives reduced bonding to allow fluid access to absorbent material. This optimizes absorbent material usage efficiency while maintaining manufacturing feasibility through targeted bonding adjustments.

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

This design improves fluid distribution and retention, reducing leakage and optimizing absorbent material usage by allowing preferential delamination in the intermediate section, thus improving the overall performance of the absorbent article.

Implementation Method 1

These channels can help quickly distributing urine along their length to better use the absorbent capacity of the absorbent core

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

The absorbent material is typically a mixture of cellulose fibers and superabsorbent polymer particles (SAP)

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

the delamination pressure of the swollen neighboring superabsorbent material

Methodology Applied
Scientific EffectSwelling: Hydrogel

Data Source

PatentEP4585197A1Absorbent article comprising a channel with varying bond strength
Publication Date: 2025.07.16 PROCTER & GAMBLE CO
  • EP4585197A1 patent drawingFigure 1
  • EP4585197A1 patent drawingFigure 2
  • EP4585197A1 patent drawingFigure 3

AI summary

A personal hygiene absorbent article (20) comprising at least one elongated, absorbent material-free channel (26) having a front end (62) and a back end (66) and a middle point (64). The channel comprises a channel bond (27) between the core wrap top layer (45) and the core wrap bottom layer (46). The channel bond strength varies along the length of the channel so that the bond strength in an intermediate section (102) is weaker than the bond strength in a front section (100)and a crotch section (104). The bond strength is measured in minutes for each section according to the Static Peel Force Time Test disclosed herein.