Diaper Absorbent Slit-and-Groove Structure for Crotch Conformability
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Solution Overview
Problem
Existing disposable diapers face challenges in maintaining a urine receiving space and conformability in the crotch area due to reduced shape retention and rigidity after urine absorption, particularly when superabsorbent polymer particles expand.
Innovation Solution
A disposable diaper design featuring elongated slits in the longitudinal direction with grooves in a continuous pattern, recessed from the surface and compressed in the thickness direction, with varying thickness and area ratios in the center and side regions, enhancing shape retention and conformability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If grooves are provided by compression in a uniformly dense pattern over the entire absorbent to improve shape retention, then shape retention is improved, but the bottom portion becomes less likely to bend and deform in accordance with crotch width (conformability deteriorates)
Solution Approach 1:
The patent applies different groove patterns to different regions of the absorbent: the crotch portion has a first groove pattern with specific spacing and orientation, while the waist portion has a second groove pattern with different spacing and orientation. This local differentiation allows the crotch region to maintain both shape retention and conformability, while the waist region provides structural support, thereby resolving the contradiction between uniform shape retention and regional conformability requirements.
Solution Approach 2:
The absorbent is divided into distinct functional regions (crotch portion and waist portion) with different groove patterns. The crotch portion uses a groove pattern that allows bending and deformation, while the waist portion uses a different pattern for structural support. This segmentation enables each region to optimize its local properties without compromising the overall structure, resolving the contradiction between global shape retention and local conformability.
2Adaptability or versatility
If slits are formed to facilitate deformation into U-shaped cross-section for conformability, then conformability is improved, but rigidity of lateral walls is reduced (urine receiving space stability deteriorates)
Solution Approach 1:
The patent uses grooves with compressed bottom portions that create a corrugated or fluted structure within the absorbent. This structure acts as internal reinforcement similar to flexible shells, allowing the lateral walls to maintain rigidity and support the urine receiving space while still enabling the necessary deformation for conformability. The groove structure provides mechanical strength without requiring solid, rigid material.
Solution Approach 2:
The patent introduces grooves that extend through the thickness of the absorbent, creating a three-dimensional structural reinforcement. This vertical dimension of grooves provides rigidity to the lateral walls while allowing horizontal deformation. The grooves create internal scaffolding that maintains structural integrity during the deformation process, resolving the contradiction between conformability and lateral wall rigidity.
3Quantity of substance
If superabsorbent polymer particles are used to enhance absorption capacity, then absorption function is improved, but shape retention is reduced when particles expand due to urine absorption
Solution Approach 1:
The grooves are pre-formed in the absorbent before urine absorption occurs. These pre-formed grooves with compressed bottom portions create a structural framework that maintains the absorbent's shape even as the superabsorbent polymer particles expand. The preliminary structural reinforcement prevents excessive deformation and maintains the U-shaped cross-section, allowing the absorbent to achieve high absorption capacity while retaining its functional shape.
Solution Approach 2:
The patent combines superabsorbent polymer particles with a structured matrix containing grooves and compressed portions. This composite structure integrates the high absorption capacity of the polymer particles with the shape-retaining properties of the grooved matrix. The grooves act as a structural skeleton that constrains the expansion of polymer particles, maintaining overall shape retention while allowing local absorption, thereby resolving the contradiction between absorption capacity and shape retention.
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 design improves maintainability of the urine receiving space and conformability by allowing the absorbent to bend and deform with the crotch width, while maintaining rigidity and absorption function, reducing leakage.
Implementation Method 1
an absorbent formed by mixing and accumulating pulp fibers and superabsorbent polymer particles
Implementation Method 2
superabsorbent polymer particles expand due to urine absorption
Implementation Method 3
grooves being recessed from at least one of a front surface and a back surface of the absorbent to an interior of the absorbent and having a bottom portion compressed in a thickness direction
Data Source
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AI summary
[Problem] To achieve an improvement in the maintainability of a urine receiving space and conformability in the crotch. [Solution] The above problem is solved by the following configuration. An absorbent 56 has a pair of elongated slits 56L extending in a longitudinal direction LD, the slits 56L being provided on one side and the other side in a width direction WD of a crotch portion M, respectively. The absorbent 56 has a center region 56C defined between the one slit 56L and the other slit 56L, and a pair of side regions 56S defined between the slits 56L on both sides in the width direction WD and lateral edges of the absorbent 56. Grooves 53 are provided in the center region 56C and the side regions 56S in a continuous pattern in the width direction WD over 60% or more of a range thereof in the longitudinal direction LD, the grooves 53 being recessed from at least one of a front surface and a back surface of the absorbent 56 to an interior of the absorbent 56 and having a bottom portion 51 compressed in a thickness direction. The center region 56C has, as compared to the side regions 56S, a fixed thickness in the bottom portions 51 of the grooves 53 and a lower area ratio in the bottom portions 51 of the grooves 53.