White Ink Composition Printing on Low-Absorbency Media
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Solution Overview
Problem
Existing ink jet printing methods face issues with insufficient filling of the white ink composition due to flocculation by flocculants, particularly on non-liquid-absorbent or less liquid-absorbent printing media such as flexible packaging films and sign/graphic films, leading to poor adhesion and peeling of the coating layers.
Innovation Solution
A printing method involving the application of a treatment liquid containing a flocculant, such as polyvalent metal salts or cationic compounds, to flocculate constituents of the ink composition, followed by a white ink composition comprising resin particles, enhancing adhesion and filling on non-liquid-absorbent or less liquid-absorbent printing media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a treatment liquid containing a flocculant is used to reduce bleeding, then bleeding is reduced, but the coating layer is not sufficiently filled with white ink composition
Solution Approach 1:
The patent extracts the harmful effect of excessive flocculation on white ink filling by separating the flocculation function (applied to color inks) from the white ink application. The treatment liquid with flocculant is applied only to regions where color inks are printed, excluding the white ink coating areas, thereby preventing white ink constituents from being flocculated while still achieving bleeding reduction in color regions.
Solution Approach 2:
The patent applies different treatments to different regions: the treatment liquid containing flocculant is applied locally only to color ink printing regions, while white ink coating regions receive no flocculant treatment. This local differentiation allows bleeding control in color areas without compromising the filling quality of white ink coating layers.
2Object-affected harmful factors
If flocculant is applied to ink composition, then bleeding is reduced, but adhesion and peeling of coating layers deteriorate
Solution Approach 1:
The patent extracts the flocculant from the white ink composition itself and applies it only as a treatment liquid on the printing medium in regions where color inks are printed. This separation ensures that white ink constituents are not exposed to flocculants, maintaining their adhesion properties while still achieving bleeding reduction in color regions through the treatment liquid.
Solution Approach 2:
The treatment liquid acts as an intermediary that carries the flocculant function to color ink regions without directly contacting white ink constituents. By applying the treatment liquid to the printing medium rather than mixing it with white ink, the patent mediates the bleeding control function while protecting white ink adhesion.
3Adaptability or versatility
If white ink composition is applied on non-liquid-absorbent printing media, then printing on flexible packaging films is enabled, but insufficient filling and poor adhesion occur
Solution Approach 1:
The patent converts the harmful effect of flocculation (which causes insufficient filling) into a beneficial selective application strategy. By applying flocculant only to color ink regions and excluding white ink regions, the patent turns the potential harm into a benefit where flocculation helps color ink stability without affecting white ink filling and adhesion on non-liquid-absorbent media.
Solution Approach 2:
The patent applies local quality control by differentiating the treatment between color ink regions (where flocculant is applied to reduce bleeding) and white ink regions (where no flocculant is applied to ensure proper filling and adhesion). This local differentiation enables successful printing on flexible packaging films by addressing the specific needs of each ink type on non-liquid-absorbent surfaces.
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 method ensures sufficient filling and adhesion of the white ink composition on non-liquid-absorbent or less liquid-absorbent printing media, resulting in high-quality images with improved rub fastness and gloss.
Implementation Method 1
a treatment liquid containing a flocculant suitable to flocculate at least one constituent of an ink composition
Data Source
AI summary
A printing method is provided. The printing method includes applying a treatment liquid containing a flocculant operable to flocculate at least one constituent of an ink composition onto a printing medium, and applying at least one ink composition including a white ink composition containing a white coloring material and resin particles onto the printing medium. The volume average particle size of the resin particles varies 50% or less when the white ink composition is mixed with the treatment liquid.