Disposable Diaper Elastic Material Arrangement for Buttock Fit

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Solution Overview

Problem

Existing tape-type disposable diapers struggle to provide a good fit for wearers with rounded buttocks due to the arrangement of elastic materials, which also makes it difficult to align the diaper properly for wear.

Innovation Solution

The disposable diaper features a body with a front, middle, and back section, incorporating connecting members, fastening units, and strategically arranged side and inner elastic materials. These elastic materials are arranged diagonally and in parallel to provide a snug fit and improve alignment with the wearer's body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If traditional elastic materials are arranged in conventional patterns, then the diaper structure is simple, but the diaper cannot fit rounded buttocks properly

Engineering Contradiction:
Improvefit to buttocksVSAvoidelastic material arrangement
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The elastic materials are divided into multiple groups (first elastic material group, second elastic material group, third elastic material group) with different arrangement patterns in different regions. The first group is arranged diagonally in the back end section, the second group in parallel in the back section, and the third group diagonally in the middle section, creating segmented regional functionality to accommodate the contours of rounded buttocks

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the diaper have different elastic material arrangements tailored to local requirements. The back end section has diagonal arrangement for lateral support, the back section has parallel arrangement for vertical fit, and the middle section has diagonal arrangement for thigh coverage, with each region's elasticity optimized for its specific anatomical location

Inventive Principle:
Principle #3Local quality

2Shape

If elastic materials are arranged to fit rounded buttocks, then the diaper fit improves, but the alignment for wear becomes difficult

Engineering Contradiction:
Improvefit to buttocksVSAvoidalignment for wear
Core Design Contradiction:
ShapeVSEase of operation

Solution Approach 1:

The elastic material groups are positioned asymmetrically relative to the diaper's longitudinal axis, with the first elastic material group located in the back end section and the second group in the back section, creating an asymmetric pattern that naturally guides alignment with the wearer's body contours while maintaining fit

Inventive Principle:
Principle #4Asymmetry

3Shape

If multiple elastic material groups are arranged strategically, then the diaper fit and alignment improve, but the manufacturing complexity increases

Engineering Contradiction:
Improvefit and alignmentVSAvoidmanufacturing process
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

Multiple elastic materials are merged into grouped configurations where individual elastic elements are collected and arranged together in specific regions. The first, second, and third elastic material groups combine multiple elastic elements into unified structures that can be manufactured as integrated components, reducing the complexity of handling and positioning individual elastic elements during production

Inventive Principle:
Principle #5Merging (Combining)

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 innovative arrangement of elastic materials enhances the fit of the disposable diaper to the wearer's body, particularly around the buttocks, and facilitates easier alignment, thereby improving comfort and usability.

Implementation Method 1

left and right side elastic materials composed of a group of threadlike elastic materials provided from a front edge to a back edge of the body

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3967284B1Disposable diaper
Publication Date: 2025.04.02 KOYO CORP
  • EP3967284B1 patent drawingFigure 1
  • EP3967284B1 patent drawingFigure 2
  • EP3967284B1 patent drawingFigure 3

AI summary

A disposable diaper 1 includes: a body 2 that contains an absorber 3 with a plurality of sheets; connecting members 4L1, 4L2, 4R1, 4R2; fastening parts 5; left-and-right side elastic materials 6L, 6R; and left-and-right inner elastic materials 7L, 7R that are disposed so as to be away from these elastic materials. The absorber 3 has left-and-right outer bulge sections 3L, 3R between first recesses 8L, 8R and second recesses 9L, 9R. Groups of threadlike elastic materials that constitute the left-and-right inner elastic materials 7L, 7R are disposed in parallel in a curved manner so as to surround the absorber 3 in a back section B of the body 2, are disposed in diagonal directions toward the center so as to come together, in a boundary area between the back section B and a middle section M, are disposed in parallel in a front-back direction so as to overlap the left-and-right outer bulge sections 3L, 3R, in the middle section M, and are disposed in diagonal directions up to a front edge 2a, after overlapping left-and-right side sections of the absorber 3, so as to come together at intermediate places, in a front section F.