Sanitary Napkin Convex Portion Leakage Prevention
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Solution Overview
Problem
Existing absorbent articles, such as sanitary napkins and incontinence pads, face issues with leakage anxiety due to low height of the absorbent body towards the skin surface, leading to body fluid adhesion at standing gathers and reduced absorption efficiency, especially when the article is twisted or shifted.
Innovation Solution
An absorbent article design featuring a convex portion with a constricted shape connecting the front and rear convex portions, where both side edges are constricted inwardly, forming arc-shaped curves to prevent fluid diffusion and ensure efficient absorption, thereby reducing leakage anxiety and improving fit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the width of the front convex portion is increased to retain sufficient pulp amount, then absorption capacity is improved, but body fluid adheres to standing gathers causing leakage anxiety
Solution Approach 1:
The patent transitions from increasing width (horizontal dimension) to increasing height (vertical dimension) of the front convex portion to retain sufficient pulp amount. This dimensional change allows the absorbent body to accommodate more pulp without expanding laterally, thereby preventing body fluid from reaching the standing gathers while maintaining absorption capacity.
Solution Approach 2:
The patent changes the geometric parameters of the front convex portion by increasing its height toward the skin surface while controlling its width. This parameter adjustment enables sufficient pulp retention through vertical expansion rather than horizontal expansion, solving the contradiction between absorption capacity and fluid adhesion prevention.
2Shape
If the height of the absorbent body toward the skin side is low between front and rear convex portions, then fit is improved, but adhesion between front surface and skin surface is lowered causing body fluid to flow rearward
Solution Approach 1:
The patent introduces a concave portion with a curved surface between the front and rear convex portions. This curvature design maintains the overall fit to body contours while creating sufficient adhesion through the concave shape's contact with the skin surface, preventing body fluid from flowing rearward despite the reduced height in this region.
3Reliability
If the height of the rear convex portion is increased to block and absorb body fluid, then leakage prevention is improved, but unconformable feeling occurs at the tailbone area
Solution Approach 1:
The patent applies different height characteristics to different regions: the rear convex portion is positioned to provide necessary height for blocking and absorbing body fluid at critical areas, while the concave portion between front and rear convex portions has reduced height to conform to the tailbone area. This localized quality differentiation ensures both leakage prevention and comfort at sensitive areas.
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 constricted convex portion design enhances absorption efficiency by diffusing body fluid across the entire convex portion, preventing leakage and reducing anxiety, while maintaining a narrow width to fit snugly against the skin, ensuring effective fluid management and comfort.
Implementation Method 1
an absorbent body provided between a liquid permeable topsheet and a backsheet
Implementation Method 2
body fluid can be diffused in the entirety of the convex portion including the constricted convex portion and the rear convex portion
Data Source
AI summary
To surely prevent leakage, not to cause a wearer feel anxiety against the leakage, and to improve fit. There is provided a sanitary napkin (1) in which a convex portion (20) of an absorbent body that is high toward a skin side is formed at a skin side surface of the absorbent body (4) at a center portion in a width direction. The convex portion (20) is constituted by a front convex portion (24) designed to be provided at an area including a body fluid expelling portion of a wearer, a rear convex portion (25) designed to be provided at an area including an intergluteal cleft of the wearer, and a constricted convex portion (23) provided at an area connecting the front convex portion (24) and the rear convex portion (25) in a front-rear direction of a napkin whose both side edges are constricted toward an inner side. In particular, the rear convex portion (25) is designed to be provided at an area from a start position of the intergluteal cleft of the wearer at a crotch side, in a rearward direction, to a position exceeding the intergluteal cleft, an end position of the intergluteal cleft or at a middle position of the intergluteal cleft, the maximum width of the rear convex portion (25) being 20 to 36 mm, and the maximum width of the rear convex portion (25) and the width of the front convex portion (24) being the same width.