Water-Based Ink Ejection Stability at High Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ink-jet printing methods face challenges in achieving high-speed printing with stable ink ejection and preventing roller transfer contamination and intercolor bleeding, particularly at high printing speeds, due to issues with ink drying and nozzle clogging.
Innovation Solution
A water-based ink formulation containing a polypropylene glycol with a specific molecular weight range, a glycol ether with low viscosity, and a surfactant, which enhances ejection stability and prevents aggregation in nozzles, allowing for high-speed printing without roller transfer contamination and intercolor bleeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-speed printing is conducted with a printing speed of not less than 70 m/min, then productivity is improved, but ink ejection stability deteriorates and nozzle clogging occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the ink by specifying a polypropylene glycol with a particular molecular weight range (100-300) and controlling its content (0.1-5% by mass), along with controlling high-boiling organic solvent content (not more than 10% by mass). These parameter changes optimize the ink's physical properties to maintain stable ejection at high printing speeds of 70 m/min or more while preventing nozzle clogging.
2Productivity
If high-speed printing is conducted, then productivity is improved, but roller transfer contamination occurs due to insufficient ink drying
Solution Approach 1:
The patent controls the composition parameters of the ink, specifically limiting high-boiling organic solvents (boiling point 250°C or higher) to not more than 10% by mass and using a polypropylene glycol with molecular weight 100-300 at 0.1-5% by mass. These parameter adjustments optimize the drying characteristics of the ink to prevent roller transfer contamination while maintaining high printing speeds.
3Productivity
If high-speed printing is conducted, then productivity is improved, but intercolor bleeding occurs
Solution Approach 1:
The patent specifies precise composition parameters including polypropylene glycol with molecular weight 100-300 at 0.1-5% by mass and high-boiling organic solvents (boiling point 250°C or higher) at not more than 10% by mass. These parameter controls optimize ink drying speed and color fixation to prevent intercolor bleeding while enabling high-speed printing that maintains printing quality.
4Ease of manufacture
If conventional ink formulations are used, then ease of manufacture is maintained, but nozzle clogging occurs during high-speed printing
Solution Approach 1:
The patent modifies the ink formulation by specifying a polypropylene glycol with a narrow molecular weight range (100-300) and controlling its content at 0.1-5% by mass, along with limiting high-boiling organic solvents to not more than 10% by mass. These targeted parameter changes improve nozzle clogging resistance during high-speed printing while maintaining relative simplicity in the manufacturing process.
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 ink formulation achieves excellent ejection stability and prevents roller transfer contamination and intercolor bleeding during high-speed printing, ensuring high-quality printed materials.
Implementation Method 1
the glycol ether (b-1) has a viscosity of not more than 7.5 mPa • s as measured at 20°C
Implementation Method 2
a polypropylene glycol (B), an organic solvent (C), a surfactant (D) and water; the polypropylene glycol (B) includes a polypropylene glycol (b-1) having a polymerization degree of not less than 5 and not more than 30
Implementation Method 3
a surfactant (D) and water
Implementation Method 4
droplets of ink are directly projected onto a printing medium from fine nozzles and allowed to adhere to the printing medium to form characters or images thereon
Data Source
AI summary
The present invention relates to [1] an ink-jet printing method including a printing step of ejecting a water-based ink onto a surface of a printing medium to print characters or images thereon, in which the water-based ink includes a pigment (A), a polypropylene glycol (B), an organic solvent (C), a surfactant (D) and water; the polypropylene glycol (B) includes a polypropylene glycol (b-1) having a polymerization degree of not less than 5 and not more than 30, and a content of the polypropylene glycol (b-1) in the water-based ink is not less than 0.5% by mass and not more than 2% by mass; the organic solvent (C) includes at least a glycol ether, and the glycol ether has a viscosity of not more than 7.5 mPa•s as measured at 20°C; a content of a high-boiling organic solvent having a boiling point of not lower than 250°C in the water-based ink is not more than 5% by mass; and an amount of droplets of the water-based ink ejected upon printing the characters or images onto the printing medium is not more than 5 pL, and a printing speed used upon the printing is not less than 70 m/min in terms of a transportation speed of the printing medium, and [2] a water-based ink used in the ink-jet printing method.