Cell Absorber Structure for Faster Absorption and Uniform Swelling
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Solution Overview
Problem
Existing absorbent articles with cell absorbers face challenges in absorption rate and distribution of super absorbent polymer particles, leading to potential gel blocking, reduced absorption, and discomfort due to particle movement.
Innovation Solution
Incorporating a nonwoven fabric middle sheet between the upper and lower sheets, with concaves on the sheets to house super absorbent polymer particles, ensuring they are mostly on the middle sheet surface, and allowing for elastic expansion during absorption, while using weak bonded portions for uniform swelling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If super absorbent polymer particles are contained in cells surrounded by bonded portions of upper and lower sheets, then absorption amount can be increased, but absorption rate is lowered due to gel blocking and swelling inhibition
Solution Approach 1:
The absorber is divided into multiple cells, each containing super absorbent polymer particles. The cells are surrounded by bonded portions of upper and lower sheets, creating separate compartments that control the swelling and absorption process of each particle group independently, preventing gel blocking while maintaining high absorption capacity
Solution Approach 2:
The upper and lower sheets have different properties in different regions: bonded portions provide structural support and containment, while unbonded portions within cells allow particle swelling and liquid penetration. This local differentiation enables simultaneous achievement of high absorption amount and fast absorption rate
2Quantity of substance
If super absorbent polymer particles are allowed to swell freely, then absorption capacity is improved, but wearing feeling is deteriorated due to hardness from swelling pressure
Solution Approach 1:
By dividing the absorber into multiple small cells, the swelling pressure of super absorbent polymer particles is distributed across many small compartments rather than one large mass. This segmentation reduces the localized hardness and improves wearing feeling while maintaining overall absorption capacity
Solution Approach 2:
The upper and lower sheets act as flexible membranes that contain the swelling particles. These sheets allow controlled expansion within cells while preventing excessive swelling pressure from transmitting to the wearer, thus maintaining comfort
3Length of stationary object
If cell volume is reduced to ensure sufficient absorption, then article thickness is reduced, but absorption rate is lowered due to insufficient space for particle expansion
Solution Approach 1:
The absorber is segmented into multiple cells with optimized individual volumes. This segmentation allows efficient space utilization where each cell contains just enough particles for rapid absorption, while the collective volume of all cells provides sufficient total absorption capacity without excessive thickness
Solution Approach 2:
The cell structure parameters (size, shape, distribution) are optimized to balance thickness and absorption rate. By controlling cell dimensions and arrangement, the invention achieves fast absorption rate through adequate particle expansion space while maintaining reduced overall article thickness
4Ease of operation
If nonwoven fabrics are used for upper and lower sheets, then flexibility and comfort are improved, but super absorbent polymer particles may leak from gaps among fibers
Solution Approach 1:
Nonwoven fabric sheets are used as flexible membranes that provide both comfort and particle containment. The fiber network structure of the nonwoven fabrics creates a matrix that retains super absorbent polymer particles through physical entanglement and friction, preventing leakage while maintaining flexibility and comfort
Solution Approach 2:
The nonwoven fabrics have different local densities and fiber arrangements: tighter regions provide particle retention, while more open regions allow breathability and comfort. This local quality differentiation enables simultaneous achievement of particle retention and comfort
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
Enhances absorption rate and prevents gel blocking, reduces particle movement noise, and maintains comfort by promoting uniform swelling and liquid diffusion.
Implementation Method 1
Excretion liquid such as urine and menstrual blood passes through the top sheet and is absorbed and held by the absorber
Implementation Method 2
when the volume of the super absorbent polymer particles in the state of saturated absorption in each cell is sufficiently larger than the volume of the cell, the super absorbent polymer particles fill an inside of the cell upon the absorption
Implementation Method 3
a concave depressed to outsides of each cell in a spread state being formed by embossing the upper sheet at each cell
Implementation Method 4
the middle sheet is compressed in a thickness direction at the bonded portions and is expanded to inside of the concave within the cell
Data Source
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AI summary
An absorption rate in an absorbent article including a cell absorber is improved. The above-mentioned problem is solved by an absorbent article including an absorber 50 having a plurality of cells 55 surrounded by bonded portions 54 of an upper sheet 51 and a lower sheet 52, the upper sheet 51 and the lower sheet 52 not bonded at the cells, and a particulate material including super absorbent polymer particles 53 contained in the cells 55, in which at least one of the upper sheet 51 and the lower sheet 52 in the cells 55 is formed into concaves 50c depressed to outsides of the cells 55 in a spread state, a middle sheet 80 made of a nonwoven fabric is interposed between the upper sheet 51 and the lower sheet 52, and the middle sheet 80 is compressed in a thickness direction at the bonded portions 54 and expands to insides of the concaves 50c at portions located inside the cells 55.