UV-Transmissive Micro-Embossing Mold for Inline Curing
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Solution Overview
Problem
Existing methods for applying embossed structures, such as holograms, in radiation-curing materials during printing are complex and expensive due to the use of costly equipment like quartz glass cylinders and rolled-up strip materials.
Innovation Solution
A method using a metal cylinder with a reflective surface and a UV-transmissive micro-embossing mold that applies embossed structures directly during the printing process, eliminating the need for glass cylinders and allowing UV radiation to be reflected or scattered into the printing nip for curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If quartz glass cylinders are used to transmit UV radiation through the embossing form, then UV radiation can be delivered directly to the printing nip, but the device becomes complex and expensive
Solution Approach 1:
The invention extracts the UV radiation transmission function from the embossing form itself and separates it into a dedicated cylindrical transmission element. This allows the embossing form to be simple while the cylinder handles the complex UV transmission task, resolving the contradiction between effective UV delivery and device simplicity
Solution Approach 2:
The transparent cylinder acts as an intermediary element between the UV light source and the embossing form. It transmits UV radiation through its wall to the printing nip while allowing the embossing form to remain separate and simple, thus solving the contradiction without requiring the embossing form itself to be complex
2Productivity
If endless or rolled-up strip materials are used for embossing, then continuous production is possible, but the process becomes complex and expensive
Solution Approach 1:
Instead of using traditional endless strip materials that wrap around cylinders, the invention inverts the approach by using a stationary or simply rotating embossing form with UV radiation delivered through a transparent cylinder. This eliminates the complexity of handling endless strips while maintaining continuous production capability
Solution Approach 2:
The invention replaces the mechanical complexity of endless strip handling systems with a simpler UV radiation transmission system through a transparent cylinder. The embossing is achieved through UV-cured adhesive transfer rather than mechanical strip manipulation, reducing overall system complexity while maintaining productivity
3Manufacturing precision
If structured peel-off elements are applied on a transfer film before printing, then embossed patterns can be transferred, but additional process steps are required
Solution Approach 1:
The invention merges the embossing form function with the adhesive transfer function into a single integrated component. The embossing form includes both the structured pattern and the adhesive layer, eliminating the need for separate transfer films and peel-off elements, thus reducing process steps while maintaining precise pattern transfer
Solution Approach 2:
The embossing form is designed to perform multiple functions simultaneously: it provides the structured pattern for embossing, contains the adhesive layer for transfer, and works with the UV radiation system for curing. This multi-functionality eliminates the need for separate transfer film processes while achieving precise pattern transfer
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 approach simplifies the application of embossed structures, reduces costs, and ensures reliable in-line production of embossed features during printing without the need for additional processing steps, while maintaining high security standards.
Implementation Method 1
a UV-transmissive micro-embossing mold (13) that applies embossed structures directly during the printing process
Implementation Method 2
UV radiation is applied directly during the embossing process so that the embossed structures can no longer run
Implementation Method 3
the cylinder surface to which the micro-embossing mold is applied is designed to be scattering and the material of the micro-embossing mold is UV-transmissive. In this way it is possible to radiate the UV radiation into the nip, in which they are then reflected or scattered at the Cylinder surface
Data Source
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AI summary
The method involves applying a forming die (13) on the surface of a cylinder (10) or sleeve (110), and contacting a linear pressure nip with the radiation curable materials (12a,12b). The radiation (16) acting for hardening is applied at a gusset (Z1,Z2) before or after the pressure nip. The radiation is applied in the downstream gusset with respect to a substrate transport direction. The surface of the cylinder or the sleeve is designed in a reflective or dispersive manner in the wavelength range of the radiation used for hardening. The material of the micro forming die is permeable in the wavelength range of the radiation. An independent claim is included for a device for manufacturing the embossed structures in the radiation curable materials.