Grooved Two-Layer Absorbent Core for Fluid Dispersion and Rewetting Control
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Solution Overview
Problem
Existing absorbent articles with a large slit in the upper-layer absorbent body face issues with localized absorption of excreted fluid, limited dispersion in the lower-layer absorbent body, and insufficient rewetting prevention, leading to fluid backflow towards the user's skin.
Innovation Solution
The absorbent article features a two-layer core structure with an upper-layer core having grooves recessed in the thickness direction and a lower-layer core with grooves facing the opposite direction, where the upper-layer core has a lower super absorbent polymer density in groove regions, allowing fluid to disperse and absorb over a wider area while preventing rewetting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a relatively large slit is provided in the upper-layer absorbent body, then excreted fluid can be preferentially supplied to the lower-layer absorbent body, but excreted fluid is locally absorbed in one spot in the lower-layer absorbent body and cannot be absorbed over a wide range
Solution Approach 1:
The upper-layer absorbent body is divided into multiple groove regions with recesses extending in the width direction. These segmented groove regions distribute the incoming excreted fluid across multiple locations simultaneously, preventing localized concentration and enabling wide-area absorption in the lower-layer absorbent body.
Solution Approach 2:
Groove regions are introduced as a new dimensional feature (recesses extending in the width direction) within the upper-layer absorbent body. This additional width-direction dimension allows fluid to disperse laterally across a broader area before reaching the lower layer, transforming the absorption pattern from point-based to area-based.
2Quantity of substance
If a relatively large slit is provided in the upper-layer absorbent body, then fluid can move to the lower-layer absorbent body, but excreted fluid is likely to flow back toward the user's skin
Solution Approach 1:
The upper-layer absorbent body exhibits spatially varying properties: groove regions with lower super absorbent polymer density facilitate fluid transmission to the lower layer, while non-groove regions with higher density provide rewetting prevention. This local differentiation allows simultaneous achievement of fluid transmission and skin protection.
Solution Approach 2:
The groove regions act as intermediary channels that guide excreted fluid from the upper layer to the lower-layer absorbent body. By providing dedicated transmission pathways, they enable fluid movement while preventing direct backflow to the user's skin through the non-groove regions.
3Quantity of substance
If a relatively large slit is provided in the upper-layer absorbent body, then fluid can be supplied to the lower-layer absorbent body, but the upper-layer absorbent body is not effectively utilized
Solution Approach 1:
The upper-layer absorbent body performs multiple functions simultaneously: groove regions handle fluid transmission to the lower layer, while non-groove regions provide local absorption and rewetting prevention. This multi-functionality ensures effective utilization of the entire upper-layer structure rather than serving only as a fluid conduit.
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 design enhances fluid dispersion and absorption capacity, reducing rewetting and leakage by effectively utilizing both layers, ensuring reliable fluid management and comfort.
Implementation Method 1
the liquid absorbed by the lower-layer absorbent body is sucked up by the upper-layer absorbent body and retained by the super absorbent polymer
Implementation Method 2
retained by the super absorbent polymer of the upper-layer absorbent body
Implementation Method 3
excreted fluid is supplied to the upper-layer absorbent body as well to a certain extent, but is preferentially supplied to the lower-layer absorbent body through the slit
Data Source
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AI summary
Provided is an absorbent article (1) having an upper layer core (31) and a lower layer core (32), wherein: the upper layer core (31) has a groove (35) which is depressed in the thickness direction and has a length in a prescribed direction; the upper layer core (31) has a groove region in which the groove (35) is provided and a non-groove region in which the groove (35) is not provided; at least some of the groove region is provided in a region where the upper layer core (31) and the lower layer core (32) overlap in a view from the thickness direction; and the average density of a highly absorbent polymer (34) in a skin-side part of the groove region is lower than the average density of the highly absorbent polymer (34) in a skin-side part of the non-groove region.