Methods for making zoned apertured webs
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Solution Overview
Problem
Existing methods for producing nonwoven webs with zoned apertures face challenges in maintaining constant cross machine directional widths, leading to processing and performance issues such as leakage and improper aperture opening, especially when different aperture areas, sizes, and orientations are required in various zones.
Innovation Solution
A method involving the advancement of a nonwoven web in a machine direction with weakening at specific locations in different zones, followed by incremental stretching and cross machine directional tensioning to create apertures, ensuring consistent cross machine directional widths across zones with varying aperture patterns and sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the web is stretched incrementally to create different aperture patterns in different zones, then the aperture diversity is improved, but the cross machine directional width consistency deteriorates
Solution Approach 1:
The web is divided into multiple zones along the machine direction, with each zone having different aperture patterns, sizes, and orientations. This segmentation allows each zone to be optimized for specific performance requirements while maintaining overall web integrity and consistent cross machine directional width through controlled stretching processes.
Solution Approach 2:
Different regions of the web are given different aperture characteristics tailored to their specific functional requirements. For example, certain zones may have larger apertures for high fluid flow requirements, while other zones have smaller apertures for better structural integrity, all while maintaining consistent web width across the machine direction.
2Adaptability or versatility
If the web is stretched to create varied aperture sizes and orientations, then the functional performance is improved, but the web processing reliability deteriorates
Solution Approach 1:
The web is pre-stretched and aperture patterns are established during the manufacturing process before the web is used in the final product. This preliminary action ensures that the aperture configurations are locked in place, preventing subsequent deformation or misalignment that would compromise processing reliability.
Solution Approach 2:
The stretching process carefully controls and changes physical parameters such as tensile strength, elasticity, and aperture dimensions within specific ranges that maintain web processing reliability. By optimizing these parameters, the web can accommodate varied aperture configurations while still meeting minimum performance thresholds for reliable processing.
3Ease of manufacture
If uniform aperture patterns are used throughout the web, then the web processing is simplified, but the functional performance for different zones deteriorates
Solution Approach 1:
The web is divided into multiple zones along the machine direction, with each zone having different aperture patterns, sizes, and orientations. This segmentation allows each zone to be optimized for specific performance requirements while maintaining overall web integrity and consistent cross machine directional width through controlled stretching processes.
Solution Approach 2:
Different regions of the web are given different aperture characteristics tailored to their specific functional requirements. For example, certain zones may have larger apertures for high fluid flow requirements, while other zones have smaller apertures for better structural integrity, all while maintaining consistent web width across the machine direction.
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 approach allows for the production of zoned apertured nonwoven webs with consistent cross machine directional widths, addressing processing and performance issues by enabling the creation of webs with different aperture patterns and sizes in various zones without compromising web integrity.
Implementation Method 1
incrementally stretching the nonwoven web to locally extend portions of the nonwoven web in a direction substantially parallel to a cross machine direction to cause the nonwoven web to rupture at some of the first and second pluralities of weakened locations
Implementation Method 2
applying a substantially cross machine directional tensioning force to the nonwoven web to cause the nonwoven web to further define at the some of the first and second pluralities of weakened locations
Data Source
Figure 1~2
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AI summary
A method for making a zoned apertured nonwoven web comprises providing an unapertured nonwoven web having a first plurality of weakened locations in a first pattern in a first zone and a second plurality of weakened locations in a second pattern in a second zone. The method comprises applying a substantially cross machine directional tensioning force to the nonwoven web to cause the nonwoven web to rupture at some of the first and second pluralities of weakened locations. The applying step creates a plurality of first apertures in the nonwoven web coincident with the some of the first plurality of weakened locations and a plurality of second apertures in the nonwoven web coincident with the some of the second plurality of weakened locations. The cross machine directional width of the nonwoven web after the applying step is substantially the same in the first zone and the second zone.