Bi-directional Holographic Micro-particles for Secure Paper Authentication
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Solution Overview
Problem
Current methods for incorporating diffractive or holographic security features into papers are costly and inefficient, particularly for mass-market applications, as they require labor-intensive batch processes and can result in poor adhesion to paper, leading to potential shedding and health hazards from metal materials like nickel.
Innovation Solution
Development of bi-directional holographic plastic micro-particles with a surface relief profile and metal reflective layer, designed for large-scale industrial application, featuring enhanced adhesion through heat-seal coatings and laminated structures that ensure secure bonding within the paper fibers, allowing for both sides to display a consistent diffractive image and offering improved chemical and environmental resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal holographic micro dots are sprayed or coated onto paper, then security features are added, but only half of the dots will land the correct way up and the rest will appear as a dull matt finish
Solution Approach 1:
The patent applies asymmetry by creating bi-directional holographic micro-particles with a specific structural design where the diffractive image is visible from both sides. The particle structure includes a substrate with a diffractive optical element on one side and a reflective layer on the other side, allowing light to pass through and reflect back to create a visible holographic image from either direction. This resolves the orientation problem by making the security feature functional regardless of which side faces up.
2Reliability
If metal dots are sprayed or coated onto paper, then security features are added, but the dots have no special affinity for the paper so they can become dislodged during paper flexing or printing processing
Solution Approach 1:
The patent introduces an intermediary adhesive layer between the metal holographic micro dots and the paper substrate. This adhesive layer provides special affinity for both the metal dot surface and the paper fibers, creating strong bonding that prevents dislodging during paper flexing or printing processing. The adhesive acts as a mediator that chemically or physically bonds to both surfaces, ensuring the security feature remains firmly attached throughout the document lifecycle.
3Reliability
If nickel is used in holographic micro particles, then diffractive security features are created, but nickel is a well known health hazard that can lead to allergic skin sensitisation
Solution Approach 1:
The patent replaces the harmful nickel material with alternative materials that provide the same diffractive security functionality without the health hazards. The invention uses biodegradable or non-toxic materials such as plant-based polymers, bioplastics, or other safe metallic alternatives that maintain the holographic and diffractive optical properties while eliminating allergic sensitization risks. This substitution maintains security feature functionality while removing the harmful component.
4Loss of information
If batch plating process is used for metal micro dots, then individual batches can carry batch numbers, but the process is slow and expensive
Solution Approach 1:
The patent transitions from batch processing to continuous processing methods, changing the manufacturing parameters from discrete batch operations to continuous production flows. This allows for high-speed manufacturing while maintaining batch identification capabilities through digital tracking, RFID tags, or other modern identification systems that can be applied during continuous production. The parameter change from batch to continuous processing dramatically increases productivity while preserving traceability and identification functionality.
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
This solution enables cost-effective, high-volume production of securely bonded holographic micro-particles that can be applied during the papermaking process, providing a consistent and authenticable security feature across all sides, reducing the need for high-density dot placement and minimizing health risks, while maintaining durability and chemical resistance.
Implementation Method 1
coated with heat seal adhesives designed to activate on heating to bond the micro-particles firmly into the paper fiber structure
Implementation Method 2
carrying both defined optical diffractive effects such as images switches, movement effect and colour shifts plus even smaller microscopic features
Implementation Method 3
carrying both defined optical diffractive effects such as images switches, movement effect and colour shifts
Data Source
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AI summary
This invention refers to a new security device consisting of a planar metal holographic encoded holographic platelet characterised in that the micro particle contains a holographic or diffractive image visible under magnification to an observer for verification of authenticity further characterised in that the micro dot holographic platelet contains an authenticable individual batch code where the micro particle consists of a high temperature resistant metal made by some or all of the processes defined herein.