Ink Jet Recording Device Under Heater Gap Control
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Solution Overview
Problem
Ink-jet printing on resin films faces issues with ink flowability, intercolor bleeding, and surface defects such as wrinkles and rumples due to the non-absorbent nature of synthetic resin films, and existing heating methods either fail to prevent color migration or cause adverse effects on the printing medium.
Innovation Solution
An ink-jet printing apparatus with a platen-integrated under heater that maintains a slight gap between the printing medium and the heater, using a water-based ink composition with specific pigment, polymer, and solvent formulations, and employing a line-type printing head to eject ink droplets while controlling temperature and tension to prevent color migration and surface flaws.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heating means is disposed close to the printing medium to efficiently dry ink, then ink drying efficiency is improved, but surface defects such as wrinkles and rumples occur on the printing medium
Solution Approach 1:
The heating means is designed with a non-contact structure that provides localized heating to the ink layer without contacting the printing medium surface. The heating unit is positioned at a specific distance (0.5-3.0mm) from the printing medium, creating a localized thermal field that dries ink efficiently while avoiding surface damage. This resolves the contradiction by applying heat locally to where it is needed (the ink layer) without affecting the printing medium surface quality.
2Stability of the object's composition
If heating temperature is increased to prevent color migration, then ink stability is improved, but surface defects occur on the printing medium
Solution Approach 1:
The invention changes the heating parameters by controlling the distance between the heating means and printing medium (0.5-3.0mm) and maintaining heating temperature below 80°C. This parameter optimization allows sufficient heat to prevent color migration while avoiding excessive temperature that would cause surface defects. The ink stability is maintained through controlled heating rather than high-temperature exposure.
3Use of energy by moving object
If heating means contacts the printing medium to improve heating efficiency, then energy transfer is improved, but wrinkles and rumples are caused on the printing medium
Solution Approach 1:
The invention introduces air as an intermediary medium for heat transfer between the heating unit and the printing medium. The heating means is positioned close to but not contacting the printing medium (0.5-3.0mm distance), allowing thermal energy to be transferred through convection and radiation without direct contact. This intermediary approach maintains high heating efficiency while preventing surface defects that would result from mechanical contact.
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 solution effectively prevents color migration and surface defects, ensuring high-quality prints on resin films by maintaining ink stability and adhering to the medium without causing wrinkles or rumples, while the specific ink composition enhances printing efficiency and durability.
Implementation Method 1
an under heater which heats the printing medium from a rear side surface of the printing medium opposed to a front side surface
Implementation Method 2
drying an ink containing a solvent, a colorant and a resin using the heating means after the ink is impacted on the printing medium
Data Source
Figure 1~2
Figure 3
AI summary
The present invention relates to an ink-jet printing apparatus that is capable of obtaining printed materials that are free of occurrence of color migration and have good appearance even when printed on a resin printing medium using a water-based ink, and an ink-jet printing method. The present invention provides an ink-jet printing apparatus including an ink-jet printing head that ejects a water-based ink onto a resin printing medium that is transported in a feeding direction thereof, and an under heater that heats the printing medium from a rear side surface of the printing medium opposed to a front side surface thereof which faces to the ink-jet printing head, in which the under heater is disposed at a position spaced at a distance of from 0.05 to 3.0 mm apart from the rear side surface of the printing medium upon printing, and an ink-jet printing method using the ink-jet printing apparatus.