Sanitary Article Absorbent Body Thickness Reduction via Layered Pulp and SAP
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Solution Overview
Problem
Conventional sanitary articles, such as night-use sanitary napkins, are bulky due to their thickness exceeding 5 mm, and increasing the percentage of superabsorbent polymer (SAP) powder reduces its absorption ability when not properly confined by pulverized pulp, necessitating the use of thermo-melting composite fibers which further increases thickness.
Innovation Solution
A method involving a series of zones on a conveying web where pulverized pulp and SAP powder are layered and combined in a specific sequence to form a transferable pulp-and-SAP powder layer, which is then sandwiched between sheet layers without the need for thermo-melting materials, allowing for reduced thickness and enhanced absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the thickness of the absorbent body is reduced to make the sanitary article less bulky, then the comfort is improved, but the absorption ability deteriorates because there is insufficient space for adequate SAP powder and pulverized pulp mixture
Solution Approach 1:
The absorbent body is segmented into multiple functional layers: a liquid-permeable layer for initial liquid distribution, a core layer containing the SAP powder and pulverized pulp mixture for absorption, and a liquid-impermeable layer for containment. This segmentation allows each layer to perform its specific function efficiently within a reduced overall thickness of less than 5 mm.
Solution Approach 2:
The SAP powder particles are nested within cavities formed by the pulped material matrix. The pulped material is processed to create a three-dimensional network structure with void spaces that accommodate and confine the SAP powder, maximizing the absorption capacity within a compact volume.
2Reliability
If the percentage of SAP powder is increased to improve absorption ability, then the absorption capacity is improved, but the SAP powder cannot be properly confined by pulverized pulp alone, requiring additional thermo-melting composite fibers which increases thickness
Solution Approach 1:
The pulped material is processed to specific moisture content and density parameters that enable it to act as an effective confining matrix. By controlling the physical parameters of the pulped material (moisture content of 10-30%, density, and structural integrity), it can confine high percentages of SAP powder without requiring additional binding fibers, thus maintaining reduced thickness.
Solution Approach 2:
The pulped material serves as an intermediary substance that provides both structural support and confinement for the SAP powder. Instead of using thermo-melting composite fibers as a binding agent, the processed pulped material itself acts as the confining matrix, eliminating the need for additional thickening layers.
3Reliability
If pulverized pulp is used to confine SAP powder, then the SAP powder can be contained, but the bulky nature of pulverized pulp prevents considerable reduction in absorbent body thickness
Solution Approach 1:
The pulped material undergoes parameter changes in terms of moisture content (adjusted to 10-30%), density, and structural configuration. These parameter changes transform the pulped material from a bulky loose structure to a compact, engineered matrix that provides effective confinement with minimal thickness contribution to the overall absorbent body.
Solution Approach 2:
The absorbent body creates a composite structure where processed pulped material and SAP powder are integrated at the micro-scale. The pulped material forms a continuous phase with embedded SAP powder particles, creating a synergistic composite that achieves both confinement and absorption in a thin profile of less than 5 mm.
4Strength
If thermo-melting composite fibers are added to bind SAP powder and pulverized pulp, then the binding ability is improved, but the absorption ability of SAP powder is considerably reduced
Solution Approach 1:
The invention extracts and eliminates the thermo-melting composite fibers from the absorbent body composition. By removing this binding agent, the absorption ability of the SAP powder is preserved without compromise, while the binding function is replaced by the engineered structure of the processed pulped material matrix that confines SAP powder through its three-dimensional cavity structure rather than thermal bonding.
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 method results in a sanitary article with improved absorption ability and a thickness less than 5 mm, maintaining the effectiveness of the SAP powder without the need for additional binding materials, and reducing the overall weight and thickness of the sanitary article.
Implementation Method 1
a mixture of pulverized pulp and superabsorbent polymer (SAP) powder is used to form an absorbent body. The provision of the bulky pulverized pulp facilitates the flow of liquid in the absorbent body so as to prevent the liquid from accumulating at a specific region
Implementation Method 2
increasing the percentage of the SAP powder in the absorbent body
Data Source
AI summary
A sanitary article includes an absorbent pad including an upper sheet layer, a lower sheet layer, and a pulp-and-SAP powder layer combination. The powder layer combination is constituted by alternate layers of pulverized pulp and superabsorbent polymer (SAP) powder. A method for making the sanitary article is also disclosed.