Absorbent Article Waist Elasticity Layering for Stability and Ease

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Solution Overview

Problem

Conventional pull-on disposable diapers face challenges in preventing positional displacement of the absorbent main body while maintaining easy opening of the waist opening, which can lead to discomfort and leakage.

Innovation Solution

The absorbent article incorporates a stretchy sheet with a non-stretchy sheet configuration, where the stretchy sheet is layered more heavily at the lower end to prevent displacement and less heavily at the upper end to facilitate easy opening, with the stretchy sheet positioned on the skin side to minimize contact with the absorbent core and prevent constriction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the stretching force in the lower end portion of the stretchy sheet is reduced to match the waist opening side, then the waist opening can be easily spread open, but positional displacement of the absorbent main body occurs

Engineering Contradiction:
Improveease of spreading waist openingVSAvoidpositional stability of absorbent main body
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent applies different stretching forces to different regions of the stretchy sheet. The upper end portion (waist opening side) has a first stretching force that is smaller, allowing easy spreading. The lower end portion (crotch side) has a second stretching force that is larger, preventing positional displacement of the absorbent main body. This local differentiation of mechanical properties resolves the contradiction between ease of operation and positional stability.

Inventive Principle:
Principle #3Local quality

2Device complexity

If string-like elastic members are used as waist elastic members, then the structure is simple, but the elastic members may leave marks on the wearer's skin

Engineering Contradiction:
Improvesimplicity of waist elastic member structureVSAvoidskin marks from elastic members
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical parameters of the waist elastic member by using a stretchy sheet instead of string-like elastic members. The stretchy sheet provides distributed elastic force across a larger surface area, maintaining the necessary constraining function while eliminating the concentrated pressure points that cause skin marks. This parameter change from linear to areal elastic elements resolves the contradiction between structural simplicity and skin comfort.

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 effectively suppresses positional displacement of the absorbent main body and allows for easy opening of the waist opening, enhancing comfort and reducing leakage by varying the stretching force and layering of the sheets.

Implementation Method 1

a stretchy sheet (24) and a non-stretchy sheet (21, 22), wherein the stretchy sheet (24) is capable of stretching and contracting in the lateral direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3705097B1Absorbent article
Publication Date: 2022.06.29 UNI CHARM CORP
  • EP3705097B1 patent drawingFigure 1
  • EP3705097B1 patent drawingFigure 2
  • EP3705097B1 patent drawingFigure 3

AI summary

An absorbent article includes: an absorbent main body (10); a first waist portion (20); and a second waist portion (30). The first waist portion (20) includes a stretchy sheet (24) and a non-stretchy sheet (21, 22), and the stretchy sheet (24) is capable of stretching and contracting in the lateral direction. A lower end portion of the stretchy sheet (24) is folded upward. The number of layers of the stretchy sheet is greater in the lower end portion of the stretchy sheet than in an upper end portion of the stretchy sheet.