Security Print Medium with Opacifying Layer for Polymer Documents
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Solution Overview
Problem
Polymer document substrates lack integral security features due to their non-fibrous construction, limiting the incorporation of conventional watermarking techniques, and thus require additional security elements applied post-manufacturing, which can be vulnerable to counterfeiting.
Innovation Solution
A security print medium with an opacifying layer that, when viewed in reflection, displays a multi-tonal image and reveals a hidden multi-tonal image when viewed in transmission, providing an integral security feature similar to traditional watermarks, achieved through a combination of screen elements and luminescent print layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional watermarking techniques are used in polymer substrates, then integral security features are achieved, but the non-fibrous construction of polymer substrates prevents the use of these techniques
Solution Approach 1:
The patent changes the optical parameters of the polymer substrate by incorporating luminescent materials that respond differently to reflected light versus transmitted light. This allows the substrate to display different visual characteristics (colored appearance in reflection, watermark image in transmission) without changing the fundamental non-fibrous construction of the polymer material.
Solution Approach 2:
The patent creates a composite polymer substrate by combining the base polymer material with luminescent compounds and watermark patterns. This composite structure enables the substrate to exhibit both the mechanical properties of polymer and the optical properties needed for watermarking and security features.
2Reliability
If security elements are applied after substrate manufacturing, then polymer substrate benefits are maintained, but the security elements can be detached or replicated
Solution Approach 1:
The patent merges the security features directly into the polymer substrate matrix during the manufacturing process, making the security elements integral to the substrate itself. The luminescent materials and watermark patterns are incorporated into the substrate material, so they cannot be separated or removed without destroying the substrate.
Solution Approach 2:
The patent performs preliminary incorporation of security features during substrate manufacturing rather than as a subsequent step. The watermark patterns and luminescent materials are built into the substrate structure before the document is completed, ensuring they are permanently integrated and cannot be detached.
3Manufacturing precision
If opacifying layers are added to polymer substrates, then print reception is improved, but the substrates remain transparent or translucent
Solution Approach 1:
The patent applies opacifying properties locally to specific regions of the polymer substrate where print reception is needed, rather than making the entire substrate opaque. This allows the substrate to maintain its overall transparency and translucent characteristics while providing adequate opacity in printed areas for quality print reception.
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
Enhances the security of polymer-based documents by integrating a visible, multi-tonal image that changes appearance with viewing conditions, making it difficult to counterfeit and maintaining document integrity.
Implementation Method 1
the first print, which, when viewed in transmission, has tones which are different to the tones of the screened working and which are not visible when the security print medium is viewed in reflection
Implementation Method 2
the screened working of a multi-tonal image is visible in the opacifying layer and dominates the appearance of the security print medium
Data Source
Figure 1(a)~1(d)
Figure 2
Figure 3(a)~3(d)
AI summary
A security print medium is disclosed for forming security documents therefrom. The security print medium comprises a transparent or translucent polymer substrate having first and second opposing surfaces, and at least one opacifying layer disposed on the first and/or second surfaces of the polymer substrate, the or each opacifying layer being a layer of semi-opaque material. The security print medium further comprises a first print of a multi-tonal image disposed on the first and/or second surface of the polymer substrate, the print being covered from the point of view of an observer on a first side of the security print medium by at least one of the opacifying layers which is disposed across the substrate in accordance with a screened working of the multi-tonal image in alignment with the first print of the multi-tonal image. The screened working is comprised of an array of screen elements. When the security print medium is viewed by the observer in reflected light, the screen elements dominate the appearance of the multi-tonal image and when the security print medium is viewed by the observer in transmitted light, the first print dominates the appearance of the multi-tonal image.