Composite Sealing Foil Inner Layer Adhesion and Peeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sealing foils used in product containers, such as yogurt cups, face issues with the quality of the weakening line produced by lasers, leading to inconsistent adhesion and peeling problems, especially in small areas, causing the inner layer to either stick to the lower layer or fall into the container during peeling.
Innovation Solution
A composite material for sealing foils comprising an inner layer with a self-contained weakening line and an outer layer, where the outermost inner layer is made of semicrystalline ethylene-propylene copolymer and the innermost layer is a lacquer, ensuring reliable adhesion and peeling without tearing, even in small areas, by maintaining consistent bond strength and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the inner layer area delimited by the weakening line is made small (e.g., diameter < 12 mm), then the weakening line length per unit area increases, but the adhesion reliability deteriorates causing the inner layer to either stick to the lower layer or peel off completely
Solution Approach 1:
The patent applies local quality by creating a compositional gradient within the inner layer. The inner layer comprises a first compositional region adjacent to the outer layer with different material composition than a second compositional region farther from the outer layer. This gradient structure provides varying adhesion characteristics at different locations, ensuring reliable attachment at the interface while maintaining proper peeling behavior in the bulk material, thus solving the adhesion reliability problem for small areas.
2Strength
If the adhesion strength between the inner layer and outer layer is increased, then the inner layer remains attached during peeling, but the inner layer may tear or peel off along the weakening line
Solution Approach 1:
The patent applies parameter changes by modifying the material composition parameters within the inner layer. By creating regions with different compositions (first compositional region vs. second compositional region), the patent optimizes the balance between adhesion strength and weakening line integrity. The compositional gradient allows sufficient adhesion strength to prevent premature detachment while maintaining the effectiveness of the laser-formed weakening line, avoiding both sticking and tearing problems.
3Manufacturing precision
If the laser output fluctuation is reduced, then the weakening line quality improves, but the manufacturing complexity and cost increase
Solution Approach 1:
The patent applies preliminary action by pre-optimizing the material composition of the inner layer before the weakening line formation process. By designing the inner layer with specific compositional regions that are inherently suitable for laser processing, the patent creates material conditions that are more tolerant to laser output fluctuations. This preliminary material optimization reduces the sensitivity to laser parameter variations, maintaining weakening line quality without requiring extremely precise and complex laser systems.
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 provides reliable adhesion of the inner layer to the outer layer, even in small areas, and allows for easy peeling without the risk of tearing, ensuring the contents remain within the container, improving the overall quality and functionality of the sealing foils.
Implementation Method 1
The layer (6), which is in contact with the outer layer, consists of semicrystalline ethylene-propylene copolymers which are essentially free of dienes
Implementation Method 2
The weakening line, which is preferably produced by a laser
Data Source
AI summary
Composite materials, and sealing foils prepared with such composite materials for sealing a container, where the composite materials include an inner layer configured to face the container during sealing, the inner layer being single- or multi-layer, and including a self-contained and closed weakening line; an outer layer that may be single- or multi-layer, and that is configured to be peeled from the inner layer; where an area of the inner layer delimited by the closed weakening line remains attached to the outer layer when the outer layer is peeled from the inner layer, thereby creating a hole in the inner layer; the outermost of the inner layers is in contact with the outer layer, and includes a semicrystalline ethylene-propylene copolymer that is substantially free of dienes; and the innermost of the outer layers is a barrier layer or a lacquer.