Pattern Roll Bonding Apparatus for Absorbent Articles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mechanical bonding methods for substrates in absorbent articles face issues such as bond tool breakdown, damage to laminae, inconsistent bond strength, and aesthetic defects due to high nip pressures, which lead to frequent repairs and bond defects like tearing and pinholes.
Innovation Solution
A method and apparatus using a pattern roll with three or more pattern elements and an anvil roll, where the pattern roll is biased towards the anvil roll to create a nip pressure between 40,000 PSI and 60,000 PSI, forming discrete bond regions with gap grommet regions to reduce stress on the pattern elements and enhance bond consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If extreme nip pressures are used to create strong bonds, then bond strength is improved, but bond tool breakdown occurs and laminae are damaged
Solution Approach 1:
The bonding surface is segmented into multiple discrete pattern elements (protrusions) distributed across the bonding surface. Each pattern element creates an individual bond site, distributing the total bonding force across multiple locations rather than concentrating extreme pressure at single points, thereby reducing stress on any single pattern element and preventing tool breakdown while maintaining overall bond strength.
Solution Approach 2:
The pattern elements have varying sizes, shapes, and distributions optimized for specific bonding requirements. By tailoring the local geometry and characteristics of each pattern element, the system achieves consistent bond quality across different regions without requiring extreme uniform pressure, thus protecting the bonding tool from excessive stress.
2Manufacturing precision
If high nip pressures are applied to ensure bonding, then bond consistency is improved, but laminae damage such as tearing and pinholes increases
Solution Approach 1:
Multiple discrete pattern elements distribute the bonding action across numerous small contact points rather than one large contact area. This segmentation allows each individual pattern element to apply moderate pressure sufficient for bonding without exceeding the laminae's compressive yield strength, preventing tearing and pinhole formation while achieving consistent bonds across the entire bonded area.
Solution Approach 2:
The system changes the pressure distribution parameters by using many small pattern elements instead of few large ones. This parameter change allows the use of lower peak pressures at each contact point while maintaining adequate total bonding force, thereby consistent bonding without damaging the laminae.
3Productivity
If pattern elements are used to create discrete bond sites, then bonding efficiency is improved, but pattern element deformation and failure occur due to high stresses
Solution Approach 1:
The bonding function is segmented into multiple small pattern elements rather than using fewer large elements. This segmentation reduces the stress burden on each individual pattern element, preventing deformation and failure while maintaining high bonding efficiency through the distributed action of multiple elements working simultaneously.
Solution Approach 2:
The pattern elements are designed with geometries that can withstand the cyclic loading of production without deforming. By optimizing the shape and size of each pattern element, the system creates components that have sufficient durability for continuous operation, reducing the need for frequent repairs and maintaining productivity.
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 minimizes damage to the substrates, reduces bond tool breakdown, and achieves consistent and stronger bonds with reduced hydraulic reactionary pressures and cavitation, improving the overall quality and reliability of the bonding process.
Implementation Method 1
the substrates are compressed between the anvil roll and the pattern surfaces to form a discrete bond region between the substrates
Implementation Method 2
mechanically bonding substrates together
Implementation Method 3
some of the yielded substrate material flows from under the pattern surfaces and into the gaps to form gap grommet regions
Data Source
AI summary
The present disclosure relates to methods and apparatuses for mechanically bonding substrates together. The apparatuses may include a pattern roll having three or more pattern elements protruding radially outward, wherein each pattern element includes a pattern surface. The pattern surfaces are also separated from each other by gaps having minimum widths. The pattern roll may be adjacent an anvil roll to define a nip between the pattern surfaces and the anvil roll, wherein the pattern roll is biased toward the anvil roll to define a nip pressure between pattern surfaces and the anvil roll. As substrates advance between the pattern roll and anvil roll, the substrates are compressed between the anvil roll and the pattern surfaces to form a discrete bond region between the substrates. During the bonding process, some of yielded substrate material also flows from under the pattern surfaces and into the gaps to form gap grommet regions.