Absorbent Topsheet Fluid Channels Capillary Liquid Spreading
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Solution Overview
Problem
Existing absorbent articles have limitations in spreading liquid in the lengthwise direction due to the costly non-woven inner layer required for effective liquid distribution, which restricts the wet area over which liquid flows into the absorbent core.
Innovation Solution
A topsheet configuration featuring a flexible sheet body with strip-like protrusions on both surfaces, forming fluid channels that promote capillary action and liquid spreading in the longitudinal direction, eliminating the need for a specific fiber orientation and expensive non-woven inner layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a non-woven inner layer with specifically oriented fibers is used to spread liquid in the lengthwise direction, then liquid distribution and wet area increase, but manufacturing cost increases
Solution Approach 1:
The topsheet is segmented into multiple functional layers: a liquid-pervious outer layer, a liquid-impervious middle layer with through-apertures, and a liquid-pervious inner layer. This segmentation allows each layer to perform its specific function (liquid reception, controlled passage, and distribution) without requiring expensive fiber orientation processes, achieving cost-effective liquid spreading through structural design rather than material processing
Solution Approach 2:
Different regions of the topsheet have different liquid permeability properties. The outer layer is liquid-pervious to receive liquid, the middle layer has controlled permeability through specific aperture patterns to regulate flow, and the inner layer is liquid-pervious to distribute liquid. This local differentiation of properties enables effective liquid distribution without requiring overall fiber orientation in the non-woven layer
2Speed
If the outer layer is formed with openings extending from front to rear edge for liquid passage, then liquid can rapidly pass into the absorbent core, but liquid flow is limited to a small wet area
Solution Approach 1:
The liquid passage function is segmented across three layers: rapid initial passage through outer layer openings, controlled flow through middle layer apertures, and lateral distribution through the liquid-pervious inner layer. This segmentation enables both rapid vertical passage and extended lateral distribution, resolving the contradiction between speed and wet area
Solution Approach 2:
The liquid-impervious middle layer with through-apertures acts as an intermediary between the outer and inner layers. It controls and regulates liquid flow from the outer layer to the inner layer, enabling the liquid-pervious inner layer to effectively distribute liquid laterally across a larger wet area while maintaining rapid overall passage speed
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 proposed topsheet design effectively increases the wet area for liquid distribution, allowing liquid to spread and pass through the absorbent article efficiently in the lengthwise direction, enhancing liquid transport into the absorbent core without the need for an oriented non-woven inner layer.
Implementation Method 1
forming a plurality of fluid channels for spreading liquid in a desired direction
Data Source
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AI summary
A top sheet includes a sheet body (1) having a flat liquid pervious base wall (11) with first and second surfaces (111, 112) that are opposite to each other in a normal direction (Z) relative to the sheet body (1). The base wall (11) has front and rear edges (113, 114) that are opposite to each other in a longitudinal direction (Y). The sheet body (1) further has a plurality of protrusions (12) that protrude from the first surface (111) of the base wall (11) and that are distributed along the longitudinal direction (Y) as well as a widthwise direction (X) which is transverse to the longitudinal direction (Y). The protrusions (12) are arranged in such a manner to form a plurality of open fluid channels (14) thereamong. The fluid channels (14) extend from the front edge (113) to the rear edge (114) of the base wall (11), and have dimensions in the normal and widthwise directions (Z, X) sufficient to provide capillary action.