Backside UV Curing for Radiation Curable Ink Showthrough Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ink printing devices face the challenge of showthrough, where uncured radiation curable inks bleed into porous substrates, preventing duplex printing and degrading print quality, as existing solutions require complex machinery or chemical compatibility between inks and substrates, limiting their applicability to radiation curable inks.
Innovation Solution
An ink printing device with a curing lamp located on the opposite side of the substrate partially cures the ink immediately after printing by irradiating through the substrate, using a first curing lamp for partial curing and a second lamp for complete curing on the same side, effectively preventing showthrough.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a curing lamp is placed on the same side as the printed face to cure radiation curable ink, then the ink can be cured, but showthrough occurs where uncured ink bleeds into the substrate
Solution Approach 1:
The patent inverts the conventional curing approach by placing the curing lamp on the opposite side of the substrate from the printed face. This allows UV radiation to penetrate through the substrate and cure the ink from the backside, preventing showthrough while maintaining curing effectiveness. The inversion of the curing direction is the core solution that resolves the contradiction between achieving complete cure and preventing ink bleeding into the substrate.
Solution Approach 2:
The patent transitions from conventional single-sided curing to dual-sided curing by adding a curing lamp on the opposite side of the substrate. This dimensional change from one-sided to two-sided illumination allows the ink to be cured through the substrate thickness, ensuring complete curing while preventing showthrough by eliminating the time window for ink bleeding.
2Ease of operation
If ink viscosity is reduced for better printability, then ink flow improves, but showthrough increases as low viscosity ink bleeds more into the substrate
Solution Approach 1:
The patent applies preliminary action by curing the ink immediately after deposition through backside illumination. The UV curing lamp on the opposite side of the substrate initiates polymerization of the ink right after printing, preventing the ink from bleeding into the substrate regardless of its viscosity. This preliminary curing action occurs before showthrough can occur, resolving the contradiction between printability and showthrough prevention.
3Object-affected harmful factors
If conventional drying systems are used to evaporate water from ink, then showthrough is reduced, but the machinery becomes complicated and energy intensive
Solution Approach 1:
The patent replaces the mechanical drying system with a photopolymerization-based curing system. Instead of using complex mechanical drying machinery to evaporate water and reduce showthrough, the invention uses UV radiation penetrating through the substrate to cure the ink chemically. This substitution eliminates the need for complicated drying equipment while effectively preventing showthrough through immediate curing.
4Object-affected harmful factors
If ink composition is reformulated to minimize showthrough, then showthrough decreases, but compatibility with substrate coating becomes restricted
Solution Approach 1:
The patent replaces chemical compatibility requirements with physical curing through radiation penetration. By using backside UV curing, the invention eliminates the need for specific ink composition formulations tailored to match substrate coating properties. The radiation-based curing method works with various ink compositions and substrate types, greatly enhancing adaptability and versatility while effectively preventing showthrough.
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 method efficiently minimizes showthrough across various radiation curable inks and substrates, allowing for effective duplex printing without the need for complex machinery or chemical compatibility, ensuring high print quality.
Implementation Method 1
a radiation curable ink composition that is curable upon exposure to radiation
Implementation Method 2
curing of the ink composition by exposing the ink composition to a curing lamp on the opposite side of the substrate from which the ink composition was printed such that the curing lamp irradiates through the substrate
Data Source
AI summary
An ink printing device is disclosed that incorporates a curing lamp located on the opposite side of a printed face of a printed substrate and partially cures a radiation curable ink by irradiating through the substrate. Additionally, this disclosure provides a method for partially curing radiation curable inks by exposing a radiation curable ink on a substrate to a curing lamp located opposite the printed face of the substrate.