Absorbent Article Nonwoven Fabric Fluid Diffusivity Gel Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing absorbent articles face challenges with gel blocking, where superabsorbent polymer particles absorb body fluids slowly and swell, leading to reduced absorption capability, especially during repeated fluid discharges, due to limited fluid diffusivity in the non-skin side layer.
Innovation Solution
Incorporating a nonwoven fabric with increased fluid diffusivity on the non-skin side, formed by stacking a spunbonded layer, a meltblown layer, and a spunbonded layer, including a hydrophilic agent, to enhance the absorption rate and prevent gel blocking by diffusing body fluids widely and efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a polymer sheet with superabsorbent polymers is used to reduce thickness and wearing discomfort, then the thickness and comfort are improved, but the water absorption rate becomes slower and gel blocking occurs
Solution Approach 1:
The polymer sheet is divided into multiple compartments with partitions, allowing superabsorbent polymer particles to be distributed in separate sections. When particles absorb fluid and swell, the partitions prevent them from adhering to each other, eliminating gel blocking while maintaining thin profile and rapid absorption capability
Solution Approach 2:
Different regions of the absorber are created with specific functions: compartments contain superabsorbent polymer particles for localized absorption, while partition structures provide pathways for fluid distribution. This local differentiation enables both fast absorption and prevention of gel blocking throughout the polymer sheet
2Quantity of substance
If superabsorbent polymer particles are used to absorb body fluid, then absorption capacity is improved, but gel blocking occurs when particles swell and adhere tightly, preventing fluid passage
Solution Approach 1:
The absorber is segmented into compartments that physically separate superabsorbent polymer particles. The partition walls prevent swollen particles from contacting and adhering to each other, maintaining fluid passage pathways while preserving the high absorption capacity of the polymer particles within each compartment
Solution Approach 2:
Partition structures act as intermediary elements between superabsorbent polymer particles. These partitions mediate the interaction by preventing direct contact between swollen particles, thereby eliminating gel blocking while allowing each particle to maintain its full absorption capacity within its designated compartment
3Quantity of substance
If a large amount of body fluid is discharged at once, then the absorption demand increases, but the polymer sheet cannot quickly absorb the entire fluid, increasing backflow
Solution Approach 1:
Multiple compartments provide parallel absorption pathways, allowing large volumes of fluid to be absorbed simultaneously across different sections. This segmented structure prevents overload in any single region, maintaining high absorption speed even when large amounts of fluid are discharged at once
Solution Approach 2:
The partition structures create additional dimensional pathways for fluid distribution throughout the absorber. Fluid can move laterally through partition gaps and be distributed to multiple compartments simultaneously, increasing the effective absorption surface area and speed for large-volume discharges
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 configuration allows for effective absorption of body fluids during both initial and subsequent discharges, reducing the influence of gel blocking and preventing fluid backflow, thereby improving the overall absorption capability and wearer comfort.
Implementation Method 1
the nonwoven fabric is formed by stacking a spunbonded layer, a meltblown layer, and a spunbonded layer in this order and including a hydrophilic agent
Implementation Method 2
superabsorbent polymer particles that are movably enclosed in the compartments of the bag. The absorber is configured such that the partitions are removed when the superabsorbent polymer particles absorb a body fluid and swell
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An absorbent article includes a polymer sheet (4) where a superabsorbent polymer (12) is disposed between an upper layer sheet (10) disposed on a skin side and a lower layer sheet (11) disposed on a non-skin side. The diffusion area of the lower layer sheet (11) is 1500 mm2 or greater. The diffusion area is measured by an absorption test method including: (1) preparing a specimen with a size of 100 mm x 100 mm, (2) placing a tip of a buret at a height of 10 mm above a surface of the specimen, and dropping one droplet of ion-exchanged water from the buret, and (3) after 3 minutes from a time when the droplet reaches the surface of the specimen, measuring, as the diffusion area, an area of a region of the surface of the specimen where a reflection from water is clearly visible.