Absorbent Structure Channels for Diaper Flexibility

Solution Overview

Problem

Disposable diapers with reduced cellulose fiber content face issues of increased stiffness and volume expansion when loaded with bodily fluids, leading to discomfort and reduced flexibility, which affects fit and liquid acquisition speed.

Innovation Solution

Incorporating an absorbent structure with longitudinally extending raised strips and channels free of absorbent polymer particles, which are bonded to substrate layers using thermoplastic adhesive material, to maintain mechanical stability and improve flexibility and liquid handling properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If absorbent polymer material is used to reduce cellulose fiber content for thinner structures, then absorbent capacity is improved, but stiffness increases when loaded with bodily fluids

Engineering Contradiction:

Improveabsorbent capacityVSAvoidstiffness when loaded

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The absorbent core is divided into multiple zones with different absorbent material distributions. High-absorbency regions are positioned away from the crotch area, while the crotch region has reduced absorbent material to maintain flexibility when wet. This segmentation allows different parts of the core to have different mechanical properties during use.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the absorbent core are given different material compositions and structures. The crotch region specifically has modified properties (reduced absorbent material, different fiber composition) compared to other regions, allowing it to maintain flexibility when loaded while other regions provide high absorbency.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If absorbent polymer particles of high absorption capacity are used, then absorbent capacity is improved, but volume increases significantly when loaded with body exudates

Engineering Contradiction:

Improveabsorbent capacityVSAvoidvolume when loaded

Core Design Contradiction:

Quantity of substanceVSVolume of moving object

Solution Approach 1:

The absorbent core is divided into multiple zones with different absorbent material distributions. High-absorbency regions are positioned away from the crotch area, while the crotch region has reduced absorbent material to maintain flexibility when wet. This segmentation allows different parts of the core to have different mechanical properties during use.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent distributes absorbent material non-uniformly in the planar dimensions rather than uniformly throughout. By concentrating absorbent material in specific zones (front and back regions) and leaving the crotch region relatively depleted, the overall volume expansion when loaded is controlled while maintaining high absorbent capacity in the designated regions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Length of stationary object

If cellulose fiber content is reduced to make thinner absorbent core structures, then thickness is reduced, but liquid acquisition speed decreases due to reduced void volume

Engineering Contradiction:

ImprovethicknessVSAvoidliquid acquisition speed

Core Design Contradiction:

Length of stationary objectVSSpeed

Solution Approach 1:

Different regions of the absorbent core are given different material compositions and structures. The crotch region specifically has modified properties (reduced absorbent material, different fiber composition) compared to other regions, allowing it to maintain flexibility when loaded while other regions provide high absorbency.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The absorbent core structure incorporates porous materials and maintains void volume through strategic material distribution. By using appropriate fiber compositions and creating a porous structure in key regions, liquid acquisition speed is maintained despite reduced overall thickness and reduced cellulose fiber content.

Inventive Principle:

Principle #31Porous materials

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 structure provides improved flexibility and fit in both dry and wet states, enhancing comfort and liquid acquisition speed while maintaining mechanical stability.

Implementation Method 1

bonding the first substrate layer to the second substrate layer through the channel

Methodology Applied

Scientific EffectThermoplastic adhesive bonding: Adhesive

Implementation Method 2

absorbent polymer material ensures that large amounts of bodily fluids, e.g. urine, can be absorbed by the absorbent article

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

absorbent polymer material, such as hydrogel-forming polymer material, also referred to as absorbent gelling material, AGM, or super-absorbent polymer, SAP

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentUS20240058182A1Method of making absorbent structures with channels

Publication Date: 2024.02.22 PROCTER & GAMBLE CO

AI summary

A method for making an absorbent structure for use in a disposable absorbent article is provided. The method involves the steps of providing a first moving surface having an absorbent layer-forming reservoir, providing a supply of absorbent material, and depositing a portion of the supply of absorbent material into the absorbent layer-forming reservoir. The method further involves associating the portion of the supply of absorbent material with a first substrate layer and/or a second substrate layer to define an absorbent structure having a channel therein corresponding to the one or more raised strips, and bonding the first substrate layer to the second substrate layer through the channel. The channel is substantially free of the absorbent material.