Absorbent Article Stretch Laminates With Wrinkled Films for Easier Activation
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Solution Overview
Problem
Manufacturing stretch laminates for absorbent articles is notoriously difficult and expensive, and there is a need for new stretch laminates and methods that improve performance and reduce costs while providing a snug fit for a wide range of body types.
Innovation Solution
The use of pre-activated elastomeric films with wrinkles and furrows in stretch laminates, which are bonded to cover layers using adhesives that flow into the furrows, enhancing bond strength and reducing the force required for mechanical activation, thereby improving manufacturing efficiency and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If stretch laminates are manufactured using conventional methods, then the absorbent articles can provide snug fit for various body types, but the manufacturing process is difficult and expensive
Solution Approach 1:
The elastomeric film is pre-activated before lamination to create wrinkles and furrows on its surface. This preliminary action prepares the surface topology in advance, which later enhances adhesive bonding when the film is laminated to the topsheet, thereby improving ease of manufacture while maintaining fit performance
Solution Approach 2:
The elastomeric film is selectively stretched in specific zones (stretch zones) while other areas remain relatively unstretched (anchoring zones). This creates local variations in surface topology with wrinkles concentrated in stretch zones, allowing differential bonding characteristics across different regions of the laminate that improve both manufacturability and fit
2Strength
If adhesive is applied to smooth elastomeric film surfaces, then the bonding process is simpler, but the bond strength is insufficient
Solution Approach 1:
The elastomeric film undergoes pre-activation stretching before lamination, which creates wrinkles and furrows on the surface. This preliminary surface preparation enhances adhesive bonding by increasing surface area and providing mechanical interlocking features, thereby improving bond strength without requiring additional complex surface treatment steps
Solution Approach 2:
The invention replaces complex chemical surface treatments or primers with a mechanical pre-activation process that creates surface topology through controlled stretching. This mechanical approach to surface preparation simplifies the overall process while achieving superior adhesive bonding through physical surface features
3Productivity
If high forces are applied during mechanical activation of stretch laminates, then the laminate achieves proper expansion, but the manufacturing cost and complexity increase
Solution Approach 1:
The elastomeric film is pre-activated before being incorporated into the stretch laminate. This preliminary activation creates permanent set and wrinkles in the film, which reduces the additional force needed during final mechanical activation in manufacturing, thereby improving productivity while reducing activation force requirements
Solution Approach 2:
The pre-activation process permanently changes the physical parameters of the elastomeric film by inducing controlled deformation and creating surface wrinkles. These parameter changes in the film's structural state reduce the energy and force required for subsequent activation steps, improving manufacturing efficiency
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 pre-activated stretch laminates exhibit improved bond strength, reduced manufacturing costs, and enhanced fit and containment properties, allowing for more cost-effective production of absorbent articles that conform to various body types.
Implementation Method 1
at least some of the adhesive is disposed in at least some of the furrows
Implementation Method 2
The wrinkles have furrows, and at least some of the adhesive is disposed in at least some of the furrows
Implementation Method 3
a stretch laminate having layers joined by ultrasonic bonding
Implementation Method 4
an elastomeric film attached to the cover layer, the elastomeric film having two surfaces and a skin on at least one of the surfaces
Data Source
AI summary
An absorbent article includes a chassis comprising a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet, and at least one elastically elongatable panel joined to the chassis. The elastically elongatable panel includes a stretch laminate having layers that are joined by ultrasonic bonding. The stretch laminate has at least one cover layer, an elastomeric film attached to the cover layer, the elastomeric film having two surfaces and a skin on at least one of the surfaces. The stretch laminate has at least one anchoring zone and at least one stretch zone. A portion of the skin is located in the anchoring zone and has a plurality of wrinkles, and the wrinkles have furrows.