Polyurethane-impregnated Composite Banknote Film
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Solution Overview
Problem
Banknotes and security papers face premature contamination and reduced circulation time due to their porous nature, lack of oil-repellent and water-repellent properties, and vulnerability to environmental influences, which leads to mechanical instability and increased risk of counterfeiting.
Innovation Solution
A film composite banknote with a single-layer base paper coated on both surfaces with polyurethane-impregnated plastic films, providing mechanical strength, dirt resistance, and enhanced security against forgery, while maintaining the tactile properties of paper.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If banknote paper is made porous to allow security features, then security functionality is improved, but contamination resistance deteriorates
Solution Approach 1:
The banknote is segmented into multiple functional layers: a porous base paper layer containing security features and plastic film layers providing contamination resistance. This segmentation allows each layer to perform its specific function independently while working together as a unified structure.
Solution Approach 2:
The invention uses composite materials by combining porous paper with non-porous plastic films. The paper provides security features while the plastic films provide contamination resistance, creating a composite structure that exhibits properties superior to either material alone.
2Duration of action of stationary object
If plastic films are added to protect against contamination, then circulation life is improved, but device complexity increases
Solution Approach 1:
The invention uses thin plastic film layers as flexible protective shells that conform to the banknote surface. These thin films provide effective contamination protection while adding minimal structural complexity and maintaining the banknote's flexibility.
Solution Approach 2:
The plastic film layers serve multiple functions simultaneously: they provide contamination resistance, maintain mechanical stability, and can incorporate additional security features. This multi-functionality reduces the need for separate components, thereby limiting complexity increase.
3Strength
If adhesive is used to bond paper and film, then mechanical strength is improved, but separation risk increases when adhesive fails
Solution Approach 1:
The invention applies adhesive uniformly across the entire surface area of the base paper before assembling the composite structure. This comprehensive adhesive coverage creates multiple bonding points that cushion against stress concentration, preventing premature bond failure even when some adhesive areas are compromised.
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 polyurethane-impregnated film composite banknote significantly extends its circulation life by preventing dirt penetration, maintaining mechanical stability, and enhancing security features, reducing the formation of 'mourning edges and cracks, and improving tear resistance.
Implementation Method 1
the base paper is on its two main surfaces each completely impregnated with an impregnation composition which contains at least one polyurethane
Implementation Method 2
Since banknote paper is very porous, it has a large surface area and a high surface roughness
Implementation Method 3
two plastic films which have the same surface dimensions as the base paper and cover the entire surface of the base paper on its two main surfaces
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention relates to a composite-film banknote (1) comprising an at least one-layered base paper (2) and two plastic films (4, 5), which have the same surface dimensions as the base paper and cover the entire area of both main surfaces of the base paper. The entire area of both main surfaces of the base paper (2) is impregnated with a composition forming a polyurethane impregnation. The invention further relates to a method for producing the composite-film banknote. The polyurethane impregnation (3) of the base paper (2) provides the composite-film banknote with good resistance to penetration by liquid dirt at the edges of the banknote and thus with an extended circulation life.