Elastic Strip Laminate Extrusion for Absorbent Articles
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Solution Overview
Problem
Current elastic laminates used in absorbent devices, such as disposable diapers, are costly due to excessive material usage and complex manufacturing processes, including the need for specialized equipment and handling of individual elastic strips, which also face issues with dimensional changes during processing.
Innovation Solution
A method of forming an elastic laminate by extruding elastic material directly onto a nonwoven web in a machine direction and discontinuously in the cross-direction, allowing for non-uniform thickness and spacing, which reduces material and manufacturing costs, and simplifies the manufacturing process by eliminating the need for separate handling and attachment of elastic strips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If elastic material is applied continuously in cross-direction and machine direction, then elastic laminate provides good coverage and functionality, but material cost increases
Solution Approach 1:
The elastic material application is segmented into discrete strips spaced at intervals across the nonwoven web, rather than continuous coverage. This segmentation maintains functional elasticity where needed while significantly reducing overall material consumption and cost.
Solution Approach 2:
Elastic material is applied with non-uniform thickness across the strip width, with greater concentration at edges and less in the middle portion. This local quality variation optimizes elastic performance at critical areas (edges) while reducing material usage in less critical areas (center).
2Quantity of substance
If individual strips of elastic material are cut and attached to nonwoven materials, then elastic material usage is reduced, but processing complexity and manufacturing cost increase
Solution Approach 1:
The elastic strip formation and attachment processes are merged into a single continuous extrusion operation. The elastic material is extruded directly onto the nonwoven web in strip form and bonded in one step, eliminating the need for separate cutting, handling, and attachment equipment.
Solution Approach 2:
The elastic material is applied continuously in the machine direction through uninterrupted extrusion, maintaining continuous production flow. This eliminates discontinuous operations such as cutting individual strips and manually or mechanically attaching them, thereby simplifying processing.
3Manufacturing precision
If dimensional growth during processing is accounted for by reverse engineering, then desired end dimensions are achieved, but processing complexity increases
Solution Approach 1:
Dimensional growth is compensated for in advance during the extrusion process by pre-calculating and adjusting the extrusion parameters. This preliminary action ensures that the elastic strips achieve the desired final dimensions after processing without requiring complex reverse engineering calculations during production.
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 reduces material and manufacturing costs, simplifies the manufacturing process, and improves the integrity of the elastic laminate by minimizing creep and maintaining dimensions without significant growth during processing, resulting in a more cost-effective and efficient production of elastic laminates for absorbent articles.
Implementation Method 1
extruding an elastic material onto the first nonwoven web
Implementation Method 2
The elastic laminate may be cut into a pattern or a portion of the elastic laminate may be cut into a pattern
Implementation Method 3
activating via stretching the elastic laminate only at the location of the one or more elastic strips
Data Source
Figure 1A
Figure 1B
Figure 1C~1D
AI summary
Systems and methods for forming an elastic laminate may be disclosed. For example, an elastic material may be extruded onto a first nonwoven web. In the extrusion, the elastic material may be directly applied to the first nonwoven web continuously in a machine direction and discontinuously in a cross direction to form the elastic laminate with one or more elastic strips on the first nonwoven web. The elastic material may also be applied unevenly or non-uniformly in the cross direction strips on the first nonwoven web. A second nonwoven web may be bonded to the first nonwoven web with the one or more elastic strips. The first or second nonwoven may also be pre-activated to further improve stretch and/or softness.