Stretchable Sheet Anvil Roll Grooves for Elastic Member Retention
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Solution Overview
Problem
Existing methods for manufacturing stretchy sheets face challenges in securely attaching elastic members without cutting or causing them to protrude or come off, especially when multiple elastic members with varying diameters are used, due to issues with adjusting the depth and width of depressed portions during the welding process.
Innovation Solution
A method involving an anvil roll with projection portions and groove portions on its surface that guide and restrict the elastic members, allowing them to be cut and joined without protrusion or detachment, by ensuring the groove width and depth accommodate the elastic members effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the width between welded portions is narrowed to securely hold the elastic member, then the elastic member is prevented from coming off, but the elastic member may break when forming the welded portions
Solution Approach 1:
The anvil roll surface is designed with localized groove portions that create different spatial constraints at different locations. The groove width is specifically designed to be wider than the elastic member diameter, providing local accommodation space that prevents both breakage during welding and coming off after cutting.
Solution Approach 2:
The groove portions on the anvil roll act as an intermediary structure between the elastic member and the welded portions. This intermediary feature provides the necessary spatial buffer zone that allows the elastic member to be securely held without being subjected to excessive compression forces that would cause breakage.
2Strength
If the width between welded portions is widened to prevent cutting the elastic member, then the elastic member is not cut, but there is a risk the elastic member will come off during manufacturing
Solution Approach 1:
Instead of uniformly widening the space between welded portions across the entire width, the invention applies localized groove features only at specific positions where elastic members are placed. This provides retention functionality exactly where needed without unnecessarily increasing the overall width between welded portions.
Solution Approach 2:
The retention function is segmented into discrete groove portions on the anvil roll surface, with each groove serving a specific elastic member position. This segmentation allows precise control of retention at each location without affecting the overall layout and width requirements of the welded portion arrangement.
3Manufacturing precision
If the depressed portion depth and width are adjusted to accommodate multiple elastic members with different diameters, then elastic members can be attached without protrusion, but there is no room in the depressed portion causing risk of protrusion or coming off
Solution Approach 1:
The groove portions are designed with specific dimensional parameters where the groove width is larger than the elastic member diameter. This parameter relationship creates sufficient clearance space that accommodates elastic members with varying diameters while maintaining proper positioning and preventing protrusion or coming off.
Solution Approach 2:
The groove portions provide dynamic adaptability to accommodate elastic members with different diameters. The larger groove width allows elastic members to be properly contained regardless of their specific diameter, while the groove structure maintains consistent positioning functionality across different sizes.
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
Prevents elastic members from being cut or coming off during the manufacturing process, enabling secure attachment and stable joining of elastic members between sheets, even with varying thicknesses and stretch factors.
Implementation Method 1
an outer circumferential surface of the anvil roll has a plurality of projection portions that project outside in a radial direction of the anvil roll, wherein the projection portions have a groove portion along a rotational direction of the anvil roll
Data Source
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AI summary
Provided is a stretchable sheet manufacturing method including: a step for supplying first and second sheets (11, 12) and an elastic member (14); and a bonding step for forming a pair of welds (jP) on both sides of the elastic member (14) and bonding the first and second sheets (11, 12). A plurality of protruding sections (231) of an anvil roll (23) have a groove section (232), and in the intersecting direction cross-section of the groove section (232), when intersection points between a line (X1) connecting starting edges (232s) of first side wall sections (232iu) of the groove section (232) and lines (X2) along which second side wall sections (232id) extend toward the respective starting edge (232s) sides are denoted as first and second intersection points (Y1, Y2), the separation distance (W1) between the starting edges (232s) is longer than the distance (W2) between the first and second intersection points (Y1, Y2).