Flat-bed Screen Printing with Movable Magnet Assemblies
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Solution Overview
Problem
Existing security document printing processes face inefficiencies due to waiting times and potential blurring of magnetic images when using rotary magnetic orienting devices with flat-screen printing equipment, which limits the speed and quality of magnetic pigment particle orientation in ink-based security features.
Innovation Solution
A flat-screen printing unit with movable magnet assemblies that perform a reciprocating or forth-back rolling movement to orient magnetic or magnetizable pigment particles in a wet ink or coating composition, allowing synchronized unloading and curing to prevent image blurring, using engraved and magnetized plates with additional permanent magnets for enhanced orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a stand-alone rotary magnetic orienting device is used subsequent to a conventional flat-bed screen printing unit, then magnetic pigment particles can be oriented, but waiting times occur during the production process
Solution Approach 1:
The patent combines the screen-printing unit and magnetic orienting unit into a single integrated process station. The magnetic orienting unit is positioned directly within the printing apparatus, allowing magnetic particles to be oriented immediately after ink deposition without transferring to a separate device, thereby eliminating waiting times and improving productivity while maintaining orientation quality
2Manufacturing precision
If magnet assemblies are moved back to the first position before unloading the coated substrate material, then the magnetic orienting process can be completed, but image blurring occurs due to sequential operations
Solution Approach 1:
The patent implements a rolling movement mechanism where magnet assemblies move continuously in a forth-back rolling motion rather than reciprocating to fixed positions. This continuous movement allows the magnet assemblies to move back and the substrate to be unloaded simultaneously in a synchronized manner, preventing image blurring while eliminating idle waiting time and maintaining continuous productive action
3Manufacturing precision
If rotary drum magnetic orienting devices are used, then magnetic particle orientation is achieved, but the device complexity increases compared to flat-bed systems
Solution Approach 1:
The patent inverts the conventional approach by placing the magnetic orienting unit within the flat-bed screen printing station rather than using a separate rotary drum device. The magnet assemblies are positioned to move above or below the printing platen within the existing flat-bed structure, simplifying the overall system architecture while achieving the same magnetic orientation function
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 reduces waiting times and improves the speed and quality of magnetic image production by synchronizing the movement of magnet assemblies with substrate unloading, ensuring clear and efficient orientation of magnetic particles in security documents like banknotes and passports.
Implementation Method 1
the multiple magnet assemblies are concomitantly movable from a first position away from the upper surface of the printing platen to a second position close to the upper surface of the printing platen, hereby orienting magnetic or magnetizable pigment particles in a wet ink or coating composition
Data Source
Figure 1a~1b
Figure 1c
Figure 1d~2a
AI summary
The invention discloses a device and a process for producing indicia comprising magnetically oriented magnetic or magnetizable particles in an ink or coating composition on a sheet (5) of substrate material. The device comprises a flat-bed screen-printing unit having a flat printing screen (2) and a printing platen (1) for receiving said sheet (5), the printing platen (1) having an upper surface facing the printing screen and a first direction along its upper surface along which said sheet (5) is unloadable, and a magnetic orienting unit comprising multiple magnet assemblies (6). The magnetic orienting unit is disposed below the upper surface of the printing platen (1), said multiple magnet assemblies (6) are disposed along said first direction, and all of said magnet assemblies (6) are concomitantly movable from a first position away from the upper surface of the printing platen to a second position close to the upper surface of the printing platen.