Tamper-Evident Foil Structure with Void Layer and Patterned Separator

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Solution Overview

Problem

Existing foil structures with VOID effects are vulnerable to manipulation detection failures, as counterfeiters can reattach detached film sections to the remaining surface fragments, making the manipulation unrecognizable.

Innovation Solution

A foil structure with manipulation protection is designed, featuring a void layer and a cover layer, along with a sample layer containing a rastered area and an information layer. The void layer has distinct areas with and without separator lacquer, causing the cover film to separate from the information layers during removal, leaving visible remnants on the surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a void effect foil structure is used for tamper detection, then manipulation detection capability is improved, but the foil structure can be reattached by counterfeiters making manipulation unrecognizable

Engineering Contradiction:
Improvetamper detection reliabilityVSAvoidmanipulation evidence
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The foil structure is divided into multiple functional layers: a cover layer, a void layer with separator lacquer in specific patterns, a carrier layer with marking elements, and a substrate. This segmentation allows the void effect to trigger selectively in certain areas while preserving marking elements in other areas, creating irreversible visual changes that prevent successful reattachment without detection

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The separator lacquer is pre-applied in specific patterns to the void layer before the foil structure is applied to the substrate. This preliminary positioning ensures that when the foil is peeled off, the void effect triggers in predetermined areas, creating permanent visual evidence of manipulation that cannot be reversed by reattachment

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the cover layer is completely detached from the substrate, then the void effect is triggered, but the detached layers can be rejoined making the void effect unrecognizable

Engineering Contradiction:
Improvevoid effect visibilityVSAvoidmanipulation detection difficulty
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The separator lacquer is applied locally in specific patterns rather than uniformly across the entire void layer. This creates zones with different separation characteristics: areas with separator lacquer that trigger the void effect and areas without it that maintain adhesion. The selective local quality ensures that even if the foil is reattached, the void effect areas remain visually distinct and recognizable

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The void effect creates visual changes through optical property changes rather than color changes per se. When the void effect is triggered, the separation of layers creates visible differences in light reflection and transmission, making the manipulated areas distinctly different from non-manipulated areas, thereby preventing successful concealment of tampering

Inventive Principle:
Principle #32Color changes

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 design enhances optical detection of manipulation by creating transparent areas on the cover film and visible remnants on the surface, making it difficult for counterfeiters to reattach the film sections without being detected.

Implementation Method 1

The void layer has distinct areas with and without separator lacquer, causing the cover film to separate from the information layers during removal

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3343539B1Foil structure with tamper protection
Publication Date: 2025.05.07 SCHREINER GRP GMBH & CO KG
  • EP3343539B1 patent drawingFigure 1~2A
  • EP3343539B1 patent drawingFigure 2B~2C
  • EP3343539B1 patent drawingFigure 3A~3B

AI summary

A tamper-evident film assembly comprises a void layer (100) for triggering a void effect and a cover layer (200) arranged above the void layer (100) in the film assembly (1). The film assembly further comprises a pattern layer (400) for forming a pattern. The pattern layer (400) is arranged below the void layer (100) in the film assembly (1). The pattern layer (400) is configured such that the pattern contained in the pattern layer (400) has at least one rasterized area (410).