Elastic Structure for Absorbent Articles with Optimized Adhesive Bonding

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Solution Overview

Problem

Existing elastic structures for absorbent articles face challenges in achieving straightly extended ridges with excellent appearance and air permeability while also providing a fluffy feel, as previous methods either compromise on appearance or air permeability due to differences in ridge formation and spacing between sheet joined sections.

Innovation Solution

The elastic structure involves non-woven fabric sheet materials with specific bending resistance properties and adhesive application patterns, where the sheet joined sections are formed with a width of 0.5 to 4 mm and spacing of 4 to 8 mm, allowing for ridges to be extended in a straight line with improved fluffy feel and resistance to deformation, and using a hot-melt adhesive with specific viscosity and tack properties to ensure accurate application and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If sheet materials are joined intermittently in the extending direction to form ridges, then air permeability and fluffy feel are improved, but the ridges take the shape of fluffy feel clouds or waves with inferior appearance

Engineering Contradiction:
Improveair permeability and fluffy feelVSAvoidridge shape regularity
Core Design Contradiction:
Object-generated harmful factorsVSShape

Solution Approach 1:

The patent changes the geometric parameters of the sheet joined sections, specifically setting the width to 0.5 to 4 mm and spacing to 4 to 8 mm in the extending direction. This parameter optimization transforms the ridge shape from irregular cloud-like forms to straight, uniform ridges while preserving the air permeability and fluffy feel properties.

Inventive Principle:
Principle #35Parameter changes

2Shape

If sheet materials are joined continuously in the direction intersecting with the extending direction, then straightly extended ridges with excellent appearance and air permeability are achieved, but the fluffy feel deteriorates

Engineering Contradiction:
Improveridge straightness and appearanceVSAvoidfluffy feel
Core Design Contradiction:
ShapeVSObject-generated harmful factors

Solution Approach 1:

The patent applies different joining characteristics to different directions: continuous joining in the direction intersecting with the extending direction (to ensure ridge straightness) and intermittent joining in the extending direction (to maintain fluffy feel). This directional differentiation of joining quality resolves the contradiction between appearance and comfort.

Inventive Principle:
Principle #3Local quality

3Strength

If the width of sheet joined sections is increased, then ridge stability and resistance to deformation are improved, but air permeability and fluffy feel deteriorate

Engineering Contradiction:
Improveridge stabilityVSAvoidair permeability and fluffy feel
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent optimizes the width parameter of sheet joined sections to a specific range of 0.5 to 4 mm. This parameter setting achieves a balance where the ridges have sufficient stability and resistance to deformation while maintaining adequate air permeability and fluffy feel properties.

Inventive Principle:
Principle #35Parameter changes

4Shape

If the spacing between sheet joined sections is decreased, then ridge density and appearance are improved, but air permeability and manufacturing complexity increase

Engineering Contradiction:
Improveridge densityVSAvoidair permeability
Core Design Contradiction:
ShapeVSObject-generated harmful factors

Solution Approach 1:

The patent sets the spacing between adjacent sheet joined sections to 4 to 8 mm in the extending direction. This spacing optimization ensures sufficient ridge density for good appearance while preserving air permeability and avoiding excessive manufacturing complexity.

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 results in absorbent articles with ridges that are aesthetically pleasing, have enhanced air permeability, and maintain flexibility without becoming stiff, while providing a superior fluffy feel and resistance to compression.

Implementation Method 1

the first sheet material and the second sheet material are joined together to form sheet joined sections by an adhesive applied intermittently in the extending direction and continuously in a direction intersecting with the extending direction

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

using a hot-melt adhesive with specific viscosity and tack properties to ensure accurate application and stability

Methodology Applied
Scientific EffectPhase change (melting and solidification): Phase Change

Implementation Method 3

a plurality of elongated resilient and elastic members that is provided between the first sheet material and the second sheet material

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

when the first sheet material and the second sheet material are contracted with contraction of the resilient and elastic members, portions of the first sheet material and the second sheet material positioned between the sheet joined sections are swelled in mutually opposite directions to form ridges

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2979670B1Elastic structure for absorbent article and method for manufacturing elastic structure for absorbent article
Publication Date: 2018.12.12 DAIO PAPER CORP
  • EP2979670B1 patent drawingFigure 1
  • EP2979670B1 patent drawingFigure 2
  • EP2979670B1 patent drawingFigure 3

AI summary

An object of the present invention is to provide an elastic structure that has straightly extended ridges with excellent appearance, air permeability, and fluffy feel. The object can be attained by an elastic structure in which a first sheet material (12S) and a second sheet material (12H) are joined together to form sheet joined sections (70) by an adhesive (71) applied intermittently in an extending direction and continuously in a direction intersecting with the extending direction, resilient and elastic members (15 and 16) are fixed by the adhesive (71) to at least one of the first sheet material (12S) and the second sheet material (12H) at intersections with the sheet joined sections (70), and when the first sheet material (12S) and the second sheet material (12H) are contracted with contraction of the resilient and elastic members (15 and 16), portions of the first sheet material (12S) and the second sheet material (12H) positioned between the sheet joined sections (70) are swelled in mutually opposite directions to form ridges (80), and the sheet joined sections (70) have a width (70w) of 0.5 to 4 mm in the extending direction and spacing (70d) between the adjacent sheet joined sections (70) is 4 to 8 mm.