Apertured Substrates with Localized Hydrophobicity for Absorbent Articles
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Solution Overview
Problem
Existing absorbent articles face challenges in reducing fluid/skin contact time and preventing run-off and leakage, as fully hydrophilic topsheets retain fluids and fully hydrophobic topsheets require large apertures that lead to increased rewet and leakage issues.
Innovation Solution
The development of three-dimensional, nonwoven, apertured substrates with hydrophobic materials and hydrophilic materials positioned only around the apertures, allowing for smaller aperture sizes while maintaining effective fluid transfer and reducing skin marking and leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If fully hydrophilic topsheets are used, then fluid absorption is improved, but fluid retention increases causing wetness against skin
Solution Approach 1:
The patent applies local quality by creating distinct zones with different hydrophobicity levels: hydrophobic regions (contact angle >90°) for fluid acquisition and channeling, and hydrophilic regions (contact angle <90°) for controlled wicking. This spatial differentiation of material properties allows the topsheet to simultaneously repel fluid at the skin interface while enabling absorption in designated areas, resolving the contradiction between absorption and wetness prevention.
2Object-affected harmful factors
If fully hydrophobic topsheets are used, then fluid retention is improved keeping skin dry, but aperture size must be large causing skin marking and leakage
Solution Approach 1:
The patent uses local quality by treating only specific regions with hydrophobic agents while leaving other regions hydrophilic. The hydrophobic regions (with contact angle >90°) provide fluid acquisition and channeling capabilities with smaller apertures, while hydrophilic regions (contact angle <90°) allow controlled wicking. This localized property differentiation eliminates the need for large apertures across the entire topsheet, reducing skin marking and leakage while maintaining skin dryness.
Solution Approach 2:
The patent employs composite materials by combining hydrophobic and hydrophilic regions within the same topsheet structure. The topsheet comprises a base material with selectively applied hydrophobic treatments creating a composite structure with distinct wetting properties in different zones. This composite approach enables the topsheet to exhibit both hydrophobic fluid acquisition and hydrophilic wicking behaviors simultaneously, resolving the contradiction between skin dryness and aperture size requirements.
3Object-affected harmful factors
If smaller aperture sizes are used in hydrophobic topsheets, then skin marking is reduced, but fluid transfer efficiency decreases
Solution Approach 1:
The patent applies local quality by creating hydrophobic regions with smaller apertures for fluid acquisition (reducing skin marking) and adjacent hydrophilic regions for efficient wicking (maintaining fluid transfer). The hydrophobic regions have contact angles >90° and smaller apertures that prevent skin marking, while the hydrophilic regions with contact angles <90° ensure rapid fluid movement through capillary action, thus maintaining overall fluid transfer efficiency despite smaller aperture sizes.
Solution Approach 2:
The patent uses composite materials by integrating hydrophobic and hydrophilic regions with different aperture characteristics. The hydrophobic portion provides fluid acquisition with smaller apertures that reduce skin marking, while the hydrophilic portion ensures efficient fluid wicking and transfer. This composite structure with differentiated material properties maintains fluid transfer efficiency without requiring large apertures across the entire topsheet.
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
These substrates effectively reduce fluid/skin contact time, minimize skin marking and leakage, and achieve similar run-off benefits to fully hydrophobic topsheets with larger apertures, while keeping the wearer's skin dry.
Implementation Method 1
fully hydrophobic topsheets are sometimes desired as they do not retain the fluids
Implementation Method 2
hydrophilic materials positioned only around the apertures, allowing for smaller aperture sizes while maintaining effective fluid transfer
Data Source
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AI summary
A liquid permeable substrate for an absorbent article is disclosed. The substrate comprises a nonwoven hydrophobic layer. The substrate comprises a plurality of recesses, a plurality of projections, and a plurality of land areas. The land areas surround at least a majority of the plurality of projections and a plurality of the recesses. The plurality of recesses, the plurality of projections, and the plurality of land areas together form a first three-dimensional surface on a first side of the substrate and a second three-dimensional surface on a second side of the substrate. A hydrophilic material is positioned only proximate to at least some of the apertures.