Venting Pathways in Pressure Sensitive Adhesive Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Decorative laminates often trap gases under the adhesive layer during application, leading to bubbles and imperfections that distort images or lettering, and existing methods to prevent gas trapping either collapse or reduce bond strength.
Innovation Solution
A method and apparatus that form venting pathways in a pressure-sensitive adhesive layer by applying pressure and heat or adding additives like fibers or particulate, allowing trapped gases to pass through the adhesive layer without compromising bond strength or appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is applied in a continuous layer to bond laminate sheets, then bond strength is improved, but gas trapping occurs leading to bubbles and imperfections
Solution Approach 1:
The patent applies porous or foamed adhesive materials that contain interconnected voids or cells throughout the adhesive layer. These porous structures allow trapped gas to migrate through the adhesive to the laminate surface without compromising the bond strength, as the porous material maintains adequate adhesive properties while providing gas transport pathways.
Solution Approach 2:
The patent creates localized regions within the adhesive layer with different properties - dense adhesive regions for bonding and porous/void regions for gas transport. This local quality differentiation allows the adhesive to simultaneously provide strong bonding in contact areas and gas permeability in the porous regions, resolving the contradiction between bond strength and gas trapping prevention.
2Object-generated harmful factors
If venting channels are created in the adhesive layer to allow gas escape, then gas trapping is reduced, but bond strength deteriorates
Solution Approach 1:
Instead of creating discrete venting channels that compromise structural integrity, the patent uses uniformly distributed porous or foamed adhesive material. The interconnected voids in this porous structure provide numerous small gas migration pathways throughout the adhesive layer, allowing gas escape without creating large openings that would weaken the bond.
Solution Approach 2:
The patent enables gas to rapidly migrate through the adhesive layer by providing continuous porous pathways that allow gas to 'skip' through the adhesive to the surface. This rapid gas transport prevents bubble formation while the porous structure maintains sufficient adhesive properties for bonding, avoiding the need for large venting channels.
3Object-generated harmful factors
If adhesive is applied in a grid-like pattern to create channels for gas removal, then gas trapping is reduced, but bond strength and surface appearance deteriorate
Solution Approach 1:
The patent replaces the grid-like pattern of discrete adhesive applications with a continuous porous adhesive layer. The porous structure provides uniform gas migration pathways throughout the entire adhesive area, eliminating the need for grid patterns while maintaining both bond strength and surface appearance.
Solution Approach 2:
The patent creates a homogeneous porous adhesive layer that uniformly distributes gas migration pathways across the entire bonding surface. This homogeneous porous structure provides consistent gas venting performance without the localized weak points and appearance issues associated with grid-like adhesive patterns.
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 enables gases to escape through the adhesive layer, preventing bubbles and maintaining the integrity and appearance of decorative laminates while ensuring strong adhesion.
Implementation Method 1
forming a laminate stack including a gas permeable nonwoven layer and a pressure sensitive adhesive layer... processing the laminate stack such that a plurality of venting pathways are formed in the pressure sensitive adhesive layer to enable trapped gas to pass through the pressure sensitive adhesive layer
Implementation Method 2
applying pressure and heat to the laminate stack to reduce a ductility of the pressure sensitive adhesive layer such that the venting pathways are formed when the pressure sensitive adhesive layer is strained
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Methods and apparatus to form venting pathways in pressure sensitive adhesives for laminate stacks are disclosed. An example method includes forming a laminate stack including a gas permeable nonwoven layer and a pressure sensitive adhesive layer, a surface of the pressure sensitive adhesive layer facing a surface of the gas permeable nonwoven layer, and processing the laminate stack such that a plurality of venting pathways are formed in the pressure sensitive adhesive layer to enable trapped gas to pass through the pressure sensitive adhesive layer.