Packaging Material Hole Edge Inclination for Layer Adhesion
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Solution Overview
Problem
Packaging materials with pre-punched holes often experience adhesion issues between layers due to air pockets and discontinuities at the hole edges, leading to defects, reduced production speed, and excessive use of metal foils and polymer coatings.
Innovation Solution
The packaging material features a core layer with a radially decreasing thickness around the hole, achieved through cutting or compression, and the hole is punched from the side intended to become the inner side of the package, using an inclined puncher to improve layer adhesion during lamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an orthogonal pusher is used to punch a hole in the core material, then the hole is created efficiently, but air pockets are trapped during lamination resulting in poor adhesion between layers
Solution Approach 1:
The patent applies preliminary action by creating an inclined surface at the hole edge before lamination occurs. This inclination is formed during the hole punching process itself, allowing subsequent polymer layers to flow smoothly along the angled surface and completely fill the hole cavity, preventing air pocket entrapment and ensuring reliable layer adhesion.
2Ease of manufacture
If conventional lamination is applied over pre-punched holes, then the packaging structure is formed, but discontinuities at hole edges cause adhesion problems and packaging defects
Solution Approach 1:
The patent applies local quality by modifying only the local geometry at the hole edge (creating an inclined surface) while leaving the rest of the core material unchanged. This localized modification allows polymer layers to adhere properly at the critical hole edge area without affecting the overall manufacturing process or other areas of the packaging material.
3Reliability
If excessive amounts of metal foils and polymer coatings are used to compensate for adhesion problems, then coverage is improved, but production speed is reduced and costs increase
Solution Approach 1:
The patent applies the taking out principle by removing the problematic feature (the sharp, discontinuous edge of the punched hole) that causes adhesion failures. By extracting this geometric defect through inclination creation, the need for excessive compensatory materials is eliminated, allowing normal production speeds and material usage rates to be maintained while achieving reliable adhesion.
4Ease of manufacture
If the hole is punched from the outer side towards the inner side, then the punching process is straightforward, but the inner surface quality and adhesion are compromised
Solution Approach 1:
The patent applies inversion by reversing the conventional punching approach. Instead of punching from the outer side towards the inner side, the process punches from the inner side towards the outer side. This reversal allows the inclined surface to be formed on the inner surface, creating a geometry that promotes proper polymer layer adhesion and filling from the inside out, thereby improving inner surface quality and adhesion.
Data Source
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AI summary
The present invention relates to a packaging material comprising a core material layer having an area radially extending from an edge of a hole in said core material layer, wherein said area has a linearly or non-linearly decreasing core material layer thickness towards the edge of the hole. The invention further relates to a method for production of such a packaging material, and uses thereof.