Disposable Diaper Lotion Layout for Moisture and Flap Adhesion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing disposable diapers face issues with adhesive force degradation in the end flap portion, leading to potential rolling up of the top sheet towards the body surface and reduced elasticity, which compromises skin moisturization and fitting.

Innovation Solution

A disposable diaper design featuring a lotion portion extending in the front-back direction with varying application basis weights on the ventral, dorsal, and intermediate portions of the top sheet, combined with a stretchable sheet between the top and back sheets, to maintain adhesive strength and enhance skin moisturization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a lotion agent is applied to the top sheet to moisturize the skin, then skin moisturization is improved, but the adhesive force of the end flap portion decreases causing the top sheet to roll up

Engineering Contradiction:
Improveskin drynessVSAvoidadhesive force
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies different application basis weights of lotion agent to different regions of the top sheet. The intermediate portion (between ventral and dorsal sides) receives a higher first application basis weight for optimal skin moisturization, while the ventral and dorsal portions receive a lower second application basis weight to preserve adhesive force and prevent rolling up. This spatial differentiation of lotion concentration resolves the contradiction between moisturization effectiveness and adhesive reliability.

Inventive Principle:
Principle #3Local quality

2Reliability

If the adhesive force is increased to prevent rolling up, then structural stability is improved, but skin moisturization capability decreases

Engineering Contradiction:
Improveadhesive forceVSAvoidskin dryness
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent strategically locates the highest concentration of lotion agent in the intermediate portion of the top sheet, away from the adhesive-critical ventral and dorsal end flap portions. This allows the adhesive regions to maintain sufficient bonding strength while the intermediate region provides optimal skin contact and moisturization, thus resolving the contradiction between structural stability and skin care functionality.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If a stretchable sheet is added to improve elasticity and fitting, then adaptability is improved, but device complexity increases

Engineering Contradiction:
ImprovefittingVSAvoidstructure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent integrates the stretchable sheet functionality directly into the existing diaper structure by positioning it between the top sheet and back sheet in the end flap portion. This merging approach allows the stretchable component to work synergistically with the lotion application system and existing adhesive structures, achieving improved elasticity and fitting without requiring separate independent systems, thus limiting the increase in overall device complexity.

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 design effectively prevents top sheet rolling, maintains adhesive force, and enhances skin moisturization and fitting by using a lotion portion with controlled application weights and a stretchable sheet, ensuring a smooth contact with the wearer's skin.

Implementation Method 1

a lotion portion extending in the front-back direction at a predetermined interval in a width direction on a body-side surface of the top sheet

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentEP4046614B1Disposable diaper
Publication Date: 2026.03.25 DAIO PAPER CORP
  • EP4046614B1 patent drawingFigure 1
  • EP4046614B1 patent drawingFigure 2
  • EP4046614B1 patent drawingFigure 3

AI summary

To provide a disposable diaper capable of moisturizing the skin of a wearer and suitably maintaining an adhesive force of an end flap portion. A disposable diaper including: an absorber disposed between a liquid pervious top sheet and a liquid impervious back sheet; an end flap portion formed on each side of the absorber in a front-back direction; and a lotion portion extending in the front-back direction at a predetermined interval in a width direction on a body-side surface of the top sheet, wherein in the front-back direction, the lotion portion is disposed in an intermediate portion between a ventral side portion accounting for 20 to 45% of a front-back direction length of the top sheet from a ventral side end of the top sheet and a dorsal side portion accounting for 10 to 35% of the front-back direction length of the top sheet from a dorsal side end of the top sheet.