Ultrasonic Welding Pattern Gradient for Absorbent Article Pore Control

The welding process is divided into multiple sequential ultrasonic welding steps, each creating a distinct bonding pattern with different pore radii. The first welding step creates a first bonding pattern, the second welding step creates a second bonding pattern, and so on. This segmentation allows each layer to have optimized pore structures for different functions (drainage, absorption, protection), resolving the contradiction between process simplicity and fluid management performance.

Different bonding patterns are applied to different layers of the absorbent article, creating local variations in pore radius and bonding density. The first layer has a first bonding pattern optimized for drainage, the second layer has a second bonding pattern optimized for absorption, and the third layer has a third bonding pattern optimized for liquid impermeability. This local quality approach enables each region to perform its specific function optimally while maintaining overall system performance.

The patent applies different bonding patterns to different layers: the first bonding pattern for the first layer has different characteristics than the second bonding pattern for the second layer, which differs from the third bonding pattern for the third layer. Each bonding pattern is locally optimized to create appropriate pore radii for its specific function, enabling superior fluid diffusion and wearer comfort while managing the complexity through systematic variation rather than randomness.

The absorbent article is constructed as a composite of multiple material layers with different bonding patterns and pore radii. This composite structure combines materials and bonding configurations that work together synergistically - the first layer with its bonding pattern handles drainage, the second layer with its bonding pattern handles absorption, and the third layer with its bonding pattern handles containment, achieving superior fluid diffusion properties.

The manufacturing process is segmented into multiple ultrasonic welding steps, with each step creating a specific bonding pattern for a particular layer. The first ultrasonic welding step creates the first bonding pattern, the second ultrasonic welding step creates the second bonding pattern, and the third ultrasonic welding step creates the third bonding pattern. This segmentation enables precise control over pore radius and bonding characteristics in each layer, achieving superior fluid absorption and diffusion properties.

The patent systematically changes key parameters across welding steps: the bonding pattern geometry, the pore radius, and the material layer properties are varied between the first, second, and third ultrasonic welding steps. These parameter changes are controlled and deliberate, creating a gradient structure that optimizes fluid management while managing manufacturing complexity through systematic parameter variation rather than uncontrolled complexity.