Waterless UV Inkjet Transfer System for Variable Data Printing
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Solution Overview
Problem
Conventional printing systems cannot simultaneously handle high viscosity inks and true high-speed variable data printing processes, as they either excel at one or the other, and face challenges in cleaning residual ink from reimageable surfaces without affecting longevity.
Innovation Solution
An inkjet printing system with an imaging member, flood coat delivery unit, inkjet image applicator, viscosity control unit, and ink image transfer station, which deposits a flood coat layer, discharges an ink image, increases viscosity, and transfers the hardened image to a substrate without water, using UV-curable inks and coatings for high image quality and wear resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional offset lithography is used to print high viscosity inks, then image quality and color gamut are improved, but the system cannot accommodate high-speed variable data printing processes
Solution Approach 1:
The system separates the printing process into two distinct stages: (1) a flood coat delivery unit applies a uniform base layer of image receiving coating across the entire imaging member surface, and (2) an inkjet image applicator deposits variable data ink images only in specific patterns. This segmentation allows the high-quality imaging member to be reused while enabling high-speed variable data printing by only jetting ink where needed.
Solution Approach 2:
The patent introduces an image receiving coating layer as an intermediary between the imaging member and the ink. This coating layer acts as a transfer medium that receives the inkjet-applied variable data images and facilitates their transfer to the print substrate. The coating layer protects the imaging member from direct ink contact while enabling high-quality image reproduction.
2Manufacturing precision
If conventional offset lithography is used for high viscosity inks, then ink transfer quality is improved, but cleaning residual ink from the imaging member surface becomes difficult without affecting its longevity
Solution Approach 1:
The patent extracts the image receiving coating from the traditional dampening fluid layer in offset lithography. Instead of using water-based dampening fluids that require extensive cleaning, the system uses a specialized image receiving coating that can be cleanly removed or refreshed without damaging the imaging member. The coating is applied fresh for each printing cycle, eliminating the need for complex cleaning systems.
3Productivity
If inkjet marking systems are used for variable data printing, then printing speed and variable data capability are improved, but the system cannot handle medium or high viscosity inks
Solution Approach 1:
The patent replaces the traditional mechanical ink transfer mechanism of offset lithography with a digital inkjet deposition system. The inkjet image applicator uses precision-controlled droplet ejection to deposit variable data images directly onto the image receiving coating. This substitution enables the use of medium to high viscosity inks that can be properly transferred through the coating layer to the substrate, while maintaining high-speed variable data printing capability.
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
Enables high-quality, wear-resistant digital prints on a wide range of media by combining UV-curable inks and coatings, achieving efficient ink transfer and cleaning without water, and maintaining image quality comparable to commercial lithographic standards.
Implementation Method 1
using UV-curable inks and coatings for high image quality and wear resistance
Data Source
AI summary
A solid blanket receives a flood layer of very thin (e.g., about 10 μm or less) image receiving UV curable coating, which may be a clear, substantially clear, or tinted UV ink. A lower viscosity digital ink image may then be printed on top of the flood layer, for example by jetting UV ink on top of the flood layer. The lower viscosity UV digital ink sits on top of the thicker UV curable coating and maintains its location by surface tension interaction with the coating. The combination of ink and coating is then partially cured to a tacky state at which point it is transferred to print media via a conformable pressure nip. Since the lower viscosity jetted inks are not responsible for directly wetting the media, media latitude widens greatly. Further, no dampening fluid or fountain solution is needed to aid the transfer or the imaging.