Gluteal Cover Elastic Member Layout for Diaper Appearance

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Solution Overview

Problem

Conventional underpants-type disposable diapers with a separated outer member design suffer from a conspicuous corner on the side edge of the gluteal cover portion near the leg opening, leading to an unsightly appearance due to inclined edges.

Innovation Solution

The design incorporates a gluteal cover portion with three or more elongated elastic members along the width direction, where the central interval between the closest cover portion elastic member to the waist opening and the second member is greater than 0.5 times the front-back direction length of the gluteal cover portion, ensuring the side edge inclines obliquely downward and the corner remains inconspicuous.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the back outer member has a longer front-back direction size to cover the lower portion of the gluteal region, then the coverage area is improved, but the side edge of the gluteal cover portion forms a conspicuous corner leading to deteriorated appearance

Engineering Contradiction:
Improvecoverage area of gluteal cover portionVSAvoidside edge shape of gluteal cover portion
Core Design Contradiction:
Area of stationary objectVSShape

Solution Approach 1:

The patent applies parameter changes by controlling the front-back direction length of the back outer member to be within a specific range (1.1 to 1.5 times the front-back direction length of the side seal portion). This parameter optimization ensures sufficient coverage of the gluteal region while preventing the side edge from forming a conspicuous corner, thus resolving the contradiction between coverage area and appearance quality.

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If the gluteal cover portion extends closer to the center in the front-back direction, then the coverage is improved, but the corner on the leg opening side becomes more conspicuous

Engineering Contradiction:
Improvecoverage area of gluteal cover portionVSAvoidcorner shape on leg opening side
Core Design Contradiction:
Area of stationary objectVSShape

Solution Approach 1:

The patent controls the extension distance of the gluteal cover portion toward the center in the front-back direction within an optimized range. By limiting how far the cover portion extends, the invention achieves adequate coverage while avoiding the formation of conspicuous corners at the leg opening side, thus resolving the contradiction between coverage and appearance.

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 prevents the deterioration of the appearance caused by a conspicuous corner, ensuring a better fit and aesthetic appeal by maintaining the side edge's shape and preventing warping, thus enhancing the overall appearance of the diaper.

Implementation Method 1

the gluteal cover portion being contracted toward a center in the width direction by the cover portion elastic members

Methodology Applied
Scientific EffectElastic contraction: Elasticity

Data Source

PatentEP3639800B1Pull-up disposable diaper
Publication Date: 2023.06.07 DAIO PAPER CORP
  • EP3639800B1 patent drawingFigure 1
  • EP3639800B1 patent drawingFigure 2
  • EP3639800B1 patent drawingFigure 3

AI summary

To prevent deterioration of an appearance caused, for example, on account of a conspicuous corner in a gluteal cover portion. The above problem is solved by the following. That is, three or more elongated cover portion elastic members 16a to 16c along a width direction WD are disposed in a gluteal cover portion C of a back outer member 12B at intervals in a front-back direction LD. The gluteal cover portion C is contracted toward the center in the width direction by the cover portion elastic members 16a to 16c. The cover portion elastic member 16a located closest to a waist opening WO is disposed at an end portion of the gluteal cover portion C on the waist opening WO side, and the cover portion elastic member 16c located closest to a leg opening LO is disposed at an end portion of the gluteal cover portion C on the leg opening LO side. When a central interval between the cover portion elastic member 16a located closest to the waist opening WO and the cover portion elastic member 16b located second from the waist opening WO is represented by dA, and the front-back direction length of the gluteal cover portion C is represented by dE, dA > 0.5dE is satisfied.