Disposable Diaper Absorbent Core Slits and Topsheet Projections

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Solution Overview

Problem

Disposable diapers often cause skin irritation due to the adhesion of urine or stool, leading to redness and rashes, and they may not fit comfortably, resulting in leakage issues.

Innovation Solution

The development of a disposable diaper with an absorbent core featuring slits that extend in a longitudinal direction, providing improved fit and leakage prevention, combined with a topsheet having an uneven structure to inhibit the diffusion of excrement liquids and a core wrap sheet with enhanced liquid permeability to quickly absorb fluids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the absorbent core is made with uniform material distribution, then the absorbency is improved, but the fit to the body and leakage prevention deteriorate

Engineering Contradiction:
ImproveabsorbencyVSAvoidleakage prevention
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The absorbent core is divided into multiple regions with different material densities: a first region with higher material density and a second region with lower material density. This segmentation allows the core to provide both high absorbency in the first region and good fit and leakage prevention in the second region, resolving the contradiction between absorbency and leakage prevention.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the topsheet has a smooth surface, then the ease of operation is improved, but the diffusion of excrement liquids deteriorates

Engineering Contradiction:
Improveease of useVSAvoiddiffusion of excrement liquids
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The topsheet is provided with an uneven structure featuring protrusions and recesses on its surface. This local structural modification creates regions that inhibit the diffusion of excrement liquids while maintaining overall ease of operation, as the uneven structure is specifically positioned to address the harmful diffusion effect without compromising usability.

Inventive Principle:
Principle #3Local quality

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 solution effectively reduces skin irritation by minimizing the adhesion of excrement liquids and improves the fit and leakage prevention of the diaper, ensuring better absorbency and comfort.

Implementation Method 1

a core wrap sheet which covers the absorbent core

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

an absorbent member arranged between the two sheets

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP2656826B1Absorptive article
Publication Date: 2018.10.31 KAO CORP
  • EP2656826B1 patent drawingFigure 1
  • EP2656826B1 patent drawingFigure 2~3
  • EP2656826B1 patent drawingFigure 4(a)~5

AI summary

An absorbent article (1) of the present invention is configured by including an absorbent member 4 and a topsheet (2) which is arranged on a skin-facing surface side of the absorbent member 4, wherein the absorbent member (4) is arranged so as to include an absorbent core (40 and core wrap sheet (41) which covers at least a skin-facing surface (40a) of the absorbent core (40). The topsheet (2 has a large number of projections (25) protruding toward the skin of a wearer. A Slit (5), which extends in a predetermined direction X, and has an opening (50) on at least a non-skin-facing surface (40b) side of the absorbent core 40, is formed on the absorbent core (40). A portion of the core wrap sheet (41, which covers the skin-facing surface (40a) of the absorbent core (40), has a liquid permeation time of a low viscosity liquid of 2.5 seconds or less.