Intermeshing Activation Rolls with Buffer Regions for Multi-Directional Web Stretching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for activating extensible materials in multiple directions using multiple pairs of activation rolls are costly, complex, and prone to web damage due to high localized stress, especially when changing directions abruptly, which can lead to pinholes or tears.
Innovation Solution
A pair of intermeshing activation rolls with three-dimensional surface features and buffer regions to activate different areas of a web in different directions simultaneously, reducing localized stress and minimizing web damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple pairs of activation rolls are used to activate different areas of a web in different directions, then the activation effectiveness is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple activation functions into a single pair of rolls by creating different surface feature regions on the same roll surfaces. One region has features for activating in the machine direction while another region has features for activating in the cross direction, eliminating the need for multiple separate roll pairs
Solution Approach 2:
The activation rolls are designed with multi-functional surface features that can activate the web in different directions simultaneously. The rolls serve multiple purposes: activating in machine direction, activating in cross direction, and providing buffer regions, all within a single roll pair configuration
2Adaptability or versatility
If high localized mechanical stress is applied to activate the web, then the activation effectiveness is improved, but the web damage increases
Solution Approach 1:
The patent applies local quality by creating distinct regions on the roll surfaces with different surface features. Some regions have aggressive features for effective activation while other regions are designed as buffer zones with smoother surfaces to reduce stress concentration and prevent web damage during direction transitions
Solution Approach 2:
Buffer regions are strategically placed between areas with different activation directions to cushion the web during transitions. These buffer regions prevent abrupt stress changes that would otherwise cause pinholes or tears in the web material
3Adaptability or versatility
If abrupt direction changes are made during activation, then the activation versatility is improved, but the web damage increases due to excessive strain
Solution Approach 1:
The buffer regions are pre-positioned on the roll surfaces at locations where direction changes will occur. This preliminary arrangement ensures that the web is gradually transitioned between activation directions rather than subjected to abrupt changes, preventing strain-induced damage
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 solution allows for effective activation of webs in multiple directions without excessive strain or damage, maintaining the desired properties of elasticity and softness, and reducing the need for additional rolls and manufacturing complexity.
Implementation Method 1
As the web passes through the matched pair of activation rolls, it is subjected to relatively high localized mechanical stress from the intermeshing three-dimensional surface features. Most, if not all, of the fiber/bond breaking takes place in these areas of high localized mechanical stress.
Implementation Method 2
Activation, or incremental stretching as it is sometimes referred to, involves permanently stretching or elongating a web or portions of a web in one or more directions. As the web is stretched, some of the fibers, inter-fiber bonds, and/or intra-fiber bonds are believed to be broken.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
An apparatus for simultaneously activating two or more portions of a web in different directions. The apparatus includes a pair of intermeshing activation rolls with three-dimensional surface features disposed thereon. The three dimensional surface features are arranged in discrete regions on the rolls such that at least two of the regions provide different directions of activation. The rolls include one or more buffer regions positioned between the discrete regions on the roll that provide different directions of activation.