Disposable Diaper Elastic Leg Cuff Softness via Segmented Bonding

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Solution Overview

Problem

Existing disposable diapers fail to adequately improve the softness and touch of the elasticized regions, particularly the elasticized leg cuffs, which remain insufficient compared to the flat regions.

Innovation Solution

A disposable diaper design featuring an elasticized leg cuff with an elastic member positioned between the elastic member fixing sheet and the inner sheet, where the elastic member does not overlap the bonds in the lateral direction, allowing for a gentle wavy deformation of the outer sheet and enhancing the softness and appearance of the elasticized leg cuffs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the inner sheet and outer sheet are bonded together via adhesive layers in the elasticized region, then the structural integrity is improved, but the softness and touch of the elasticized leg cuff deteriorate

Engineering Contradiction:

Improvestructural integrityVSAvoidsoftness and touch

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The adhesive bonding is segmented into discrete laterally spaced bonds rather than continuous bonding. This segmentation allows the outer sheet to deform gently over the elastic member while maintaining structural integrity at the bond locations, resolving the contradiction between strength and softness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the outer cover have different bonding characteristics: the crotch portion has continuous or dense bonding for structural support, while the elasticized leg cuff region has sparse, laterally spaced bonds that allow softness and gentle deformation. This local differentiation resolves the contradiction by applying appropriate bonding density to each functional region.

Inventive Principle:

Principle #3Local quality

2Strength

If adhesive layers are applied in stripes extending in the lateral direction, then the bonding strength is improved, but the appearance and visual appeal of the elasticized leg cuff deteriorate

Engineering Contradiction:

Improvebonding strengthVSAvoidappearance and visual appeal

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The lateral adhesive bonding is segmented into discrete laterally spaced bonds rather than continuous stripe bonding. This creates a more aesthetically pleasing appearance in the elasticized region while maintaining sufficient bonding strength at the discrete bond locations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bonding pattern transitions from two-dimensional continuous stripe bonding to one-dimensional discrete point bonding along the lateral direction. This dimensional reduction improves appearance by eliminating visible adhesive stripes while maintaining bonding functionality.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS11298275B2Disposable diaper

Publication Date: 2022.04.12 KAO CORP

AI summary

A disposable diaper 1 has an elasticized leg cuff 10 on each longitudinally extending, lateral side of the crotch portion C. The elasticized leg cuff 10 includes an elastic member fixing sheet 5, an elastic member 6, an inner sheet 31, and an outer sheet 32 in order from the skin facing side. The inner sheet 31 and the outer sheet 32 are bonded to each other via a plurality of longitudinally extending and laterally spaced bonds 7. The elastic member 6 is located between the elastic member fixing sheet 5 and the inner sheet 31 and arranged at a location that does not overlap the bonds 7.