Absorbent Article Composite Sheet Adhesive Pattern Warping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional absorbent articles, such as disposable diapers, experience warping at the leg-surrounding portions due to the adhesion of stretchable and non-stretchable sheets, leading to degraded skin adhesion and potential urine leakage.
Innovation Solution
The absorbent article employs a composite sheet where adhesive portions extend perpendicular to the expansion and contraction direction at the cut edge of the sheets, preventing warping by ensuring the stretchable and non-stretchable sheets are bonded with adhesives in a specific pattern that crosses the expansion and contraction direction at a predetermined angle, thereby maintaining the integrity of the leg-surrounding portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive portions are applied to the entire surfaces of stretchable and non-stretchable sheets to form a composite sheet, then the bonding strength between sheets is improved, but warping occurs at the cut edge due to differential expansion and contraction
Solution Approach 1:
The continuous adhesive application is segmented into discrete adhesive portions arranged in a pattern. This segmentation allows different regions of the composite sheet to have different adhesive densities, preventing uniform contraction forces that cause warping while maintaining sufficient bonding strength at critical locations.
Solution Approach 2:
The adhesive portions are strategically positioned with varying densities across different regions of the composite sheet. Areas with higher stretchability have different adhesive density compared to less stretchable areas, creating local quality variations that compensate for differential expansion and contraction forces.
2Adaptability or versatility
If the composite sheet is made stretchable to improve fitting properties, then the adaptability to body contours is improved, but warping and gap formation occur at leg-surrounding portions
Solution Approach 1:
The adhesive structure is segmented into specific portions rather than continuous application. This segmentation maintains stretchability in regions where it is needed for fitting while preventing warping at critical areas like leg-surrounding portions through strategic adhesive placement.
Solution Approach 2:
The adhesive portions are arranged asymmetrically with different densities and patterns in different regions of the composite sheet. This asymmetric arrangement accounts for the different stretchability requirements and warping tendencies of various body contours, improving both fitting properties and adhesion reliability.
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 effectively inhibits warping and urine leakage by enhancing the integration and fitting properties of the composite sheet, ensuring better adhesion to the skin and preventing gaps.
Implementation Method 1
a composite sheet obtained by affixing, by way of a plurality of adhesive portions, a first sheet and a second sheet
Data Source
AI summary
The present invention provides an absorbent article 1 that does not easily warp in a leg-surrounding portion. The absorbent article 1 includes an absorbing member 2 in an elongated shape arranged along a longitudinal direction of the absorbent article, and a stretchable chassis 3 having a leg-surrounding portion 3a recessed inward in a width direction. At least a part of the chassis 3 is composed of a composite sheet 13 obtained by affixing a stretchable sheet 15 and a non-stretchable sheet 16 to each other by a plurality of adhesive portions 18. The leg-surrounding portion 3a has an intersection crossing an expansion and contraction direction of the chassis 3 at a predetermined angle. The plurality of adhesive portions 18 extend in a direction substantially perpendicular to the expansion and contraction direction.