Polymeric Foam Absorbent Composite Fluid Transport
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing disposable absorbent articles face challenges with fluid transport efficiency due to phenomena like 'gel-blocking,' which reduces the effectiveness of absorbent core designs that separate liquid storage and acquisition and distribution functions.
Innovation Solution
An absorbent composite is introduced, comprising a polymeric foam with specific properties and a second absorbent layer, where the polymeric foam is free of superabsorbent polymers and has an average cell size of at least 100 microns, enhancing fluid transport and absorption capacity, and is used in combination with a fluid pervious topsheet and impervious backsheet.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If superabsorbent polymers are used for liquid storage, then absorption capacity is improved, but fluid transport is reduced due to gel-blocking
Solution Approach 1:
The absorbent core is divided into functionally distinct layers: a first layer comprising superabsorbent polymer particles for liquid storage, and a second layer comprising polymeric foam for fluid acquisition and transport. This segmentation allows each layer to optimize its specific function without the negative interactions that occur when SAP forms a gel matrix that blocks fluid pathways.
Solution Approach 2:
Different regions of the absorbent core are assigned different material properties: the first layer has high absorption capacity with SAP particles, while the second layer has high fluid transport capability with open-celled polymeric foam. This local differentiation of material qualities enables simultaneous optimization of both absorption and fluid transport in different zones of the same component.
2Quantity of substance
If absorbent core separates liquid storage and acquisition/distribution functions, then absorption capacity is improved, but device complexity increases
Solution Approach 1:
The patent merges the acquisition/distribution function and liquid storage function into a single integrated absorbent core component, rather than using separate components. The core comprises a first layer with SAP particles for storage and a second layer with polymeric foam for acquisition and transport, combining multiple functions in one unified structure that simplifies the overall device architecture.
Solution Approach 2:
The absorbent core is designed as a multi-functional component that simultaneously performs liquid acquisition, fluid distribution, and liquid storage. The first layer with SAP provides storage capacity while the second layer with polymeric foam provides acquisition and distribution, allowing the single core component to fulfill multiple essential functions that would otherwise require separate elements.
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 improves fluid transport and absorption capacity, reducing strike-through time and rewet, while maintaining the absorbent composite's properties, making it suitable for applications like feminine hygiene and adult incontinence articles.
Implementation Method 1
an absorbent composite comprising a first absorbent layer comprising a polymeric foam and a second absorbent layer in fluid communication with the first absorbent layer
Implementation Method 2
an indentation force deflection of less than 75 N at 50%; or b) a constant deflection compression set of less than 25% for a deflection of 50%
Implementation Method 3
The polyurethane foam comprises the reaction product of at least one polyol component having polyethylene oxide units and a polyisocyanate component that comprises at least 75 wt-% of at least one polymeric polyisocyanate
Data Source
AI summary
Absorbent articles are described comprising an absorbent composite. The absorbent composite comprises a first absorbent layer comprising a polymeric foam having an average cell size of at least 100 microns. The polymeric foam has at least one property selected from a) an indentation force deflection of less than 75 N at 50%; or b) a constant deflection compression set of less than 25% for a deflection of 50%; or a combination of a) and b); and a second absorbent layer in fluid communication with the fluid transport layer. In another embodiment, the a second absorbent layer has an average absorption capacity of at least 20 g/g. In another embodiment, a polyurethane foam is described having an average cell size of at least 100 microns. The polyurethane foam comprises the reaction product of at least one polyol component having polyethylene oxide units and a polyisocyanate component that comprises at least 75 wt-% of at least one polymeric polyisocyanate that lacks urethane linkages. In some embodiments, the polyurethane foam is free of superabsorbent polymer. In some embodiments, the polyurethane foam has an average cell size up to 500 microns. In some embodiments, the polyurethane foam comprises at least 12 wt-% ethylene oxide units. Also described are various composites comprising the polyurethane foam described herein in combination with another substrate such as a second absorbent layer, a fluid impervious backsheet, and/or a fluid pervious topsheet.