Image forming method
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Solution Overview
Problem
Inkjet textile printing inks with high water-soluble organic solvent content face solubility issues and dye precipitation, leading to discharge defects in metal nozzle plates, especially in tapered nozzles, due to strong interactions between dyes and metal surfaces, causing ejection performance reduction and storage stability concerns.
Innovation Solution
Incorporating an adsorption inhibitor with a pKa value of 5.5 to 7.5, such as citric acid, in the inkjet textile printing ink to prevent dye adsorption on metal components, maintaining ink stability and preventing nozzle clogging, while using a metal flow channel member with tapered discharge holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the content of water-soluble organic solvent in textile printing ink is increased, then the ink can be used in inkjet textile printing, but the solubility of the dye decreases and the dye can easily precipitate
Solution Approach 1:
A metal chelating agent is introduced as an intermediary substance that binds to metal ions in the inkjet recording head through chelation. This prevents the metal ions from catalyzing dye decomposition and interacting with dye molecules to cause precipitation. The chelating agent acts as a mediator between the metal surface and dye molecules, eliminating the harmful metal-dye interaction while allowing the ink to maintain high water-soluble organic solvent content for inkjet textile printing application.
2Reliability
If textile printing dyes with cyclic or azo structure are used, then the dyeing performance is improved, but the dye strongly interacts with metal surfaces causing discharge defects
Solution Approach 1:
The metal chelating agent serves as an intermediary that preferentially binds to metal ions, forming stable chelate complexes. This prevents the dye molecules (with cyclic or azo structures) from directly interacting with metal surfaces. The chelating agent effectively mediates the interaction between dye and metal by providing an alternative binding pathway that eliminates the harmful adsorption and discharge defects.
Solution Approach 2:
The strong interaction tendency of cyclic or azo dyes with metal is converted from a harmful effect into a beneficial one. By introducing the chelating agent, the dye's affinity for metal is redirected toward the chelating agent itself, which forms stable but reversible chelate complexes. This converts the potentially harmful strong metal-dye interaction into a controlled chelation process that prevents precipitation and discharge defects.
3Manufacturing precision
If the discharge hole is tapered with smaller outlet diameter, then the ejection precision is improved, but the dye precipitate accumulates in the nozzle because cleaning is more difficult
Solution Approach 1:
The metal chelating agent performs preliminary protection by preventing dye precipitate formation before it can occur. By maintaining dye solubility and preventing precipitation through chelation of metal ions, the ink formulation ensures that no precipitate is generated to begin with. This preliminary preventive action eliminates the need for difficult cleaning operations in tapered nozzles, as there is no precipitate to remove.
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 ensures stable ejection performance and extended storage stability of the inkjet textile printing ink, reducing discharge defects and maintaining ink quality over time, even with metal nozzle plates, by inhibiting dye adsorption and decomposition.
Implementation Method 1
some specific acids can also function as adsorption inhibitors to inhibit the adsorption of a dye from a textile printing ink to the metal component of an inkjet recording head
Implementation Method 2
the inkjet textile printing ink comprises a dye, an adsorption inhibitor, a water-soluble organic solvent, and water
Data Source
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AI summary
Provided is an image forming method in which discharge defects such as displacements of ink dots and discharge failure are less likely to occur. The image forming method including discharging an inkjet textile printing ink from a plurality of ink discharge holes (317) provided in an inkjet recording head (200) is characterized in that the inkjet recording head (200) includes tapered ink discharge holes (317), ink pressurizing chambers (314), and a metal flow channel member (310) configured to connect the ink discharge holes (317) to the ink pressurizing chambers (314); the inkjet textile printing ink includes a dye, an adsorption inhibitor, a water-soluble organic solvent, and water; the inkjet textile printing ink contains 25% by weight to less than 70% by weight of the water-soluble organic solvent based on the total weight of the ink; and the adsorption inhibitor is an acid with a pKa of 5.5 to 7.5.