Printing Ink Opacity Sequencing for Color Gamut
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Solution Overview
Problem
Existing printing methods on machine-coated substrates face a trade-off between achieving high print quality and maintaining an optimal color gamut, with the use of reaction liquids often leading to decreased color gamut despite improved print quality.
Innovation Solution
A method involving a substrate treated with a reaction liquid containing a coagulation agent, where ink compositions with dispersed colorants are applied in a sequence based on the opacity of the ink layers after coagulation, forming secondary particles that optimize color gamut while maintaining high print quality and light-fastness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a reaction liquid is used to improve print quality on machine coated substrates, then print quality is improved, but color gamut decreases
Solution Approach 1:
The invention changes the parameter of ink layer opacity by controlling the coagulation process of pigment particles. By adjusting the opacity of each ink layer through coagulation agent concentration and ink formulation, the printing sequence is optimized to print inks in order of decreasing opacity, which maintains color gamut while improving print quality on machine coated substrates
Solution Approach 2:
The reaction liquid is applied to the substrate before printing to pre-condition the surface. This preliminary action modifies the substrate surface properties to control ink spreading and coagulation, thereby improving print quality without the negative effects of post-printing treatment
2Manufacturing precision
If ink compositions are printed in sequence based on dynamic surface tension to prevent inter color bleeding, then print quality is improved, but color gamut is not optimal
Solution Approach 1:
The invention changes the sequencing parameter from dynamic surface tension to ink layer opacity. By measuring and comparing the opacity of each ink layer after coagulation, the printing sequence is optimized to print inks in order of decreasing opacity (highest opacity first), which simultaneously improves print quality and maintains optimal color gamut
3Manufacturing precision
If layers are printed in order of index of refraction to improve print quality, then print quality is improved, but color gamut deteriorates
Solution Approach 1:
The invention replaces the index of refraction parameter with opacity parameter for determining printing sequence. By evaluating the opacity of each ink layer after coagulation rather than relying on index of refraction, the system achieves both improved print quality and maintained color gamut
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 approach allows for improved color gamut and print quality, particularly on machine-coated substrates, by selecting a color sequence based on ink properties post-coagulation, reducing mottling effects, and ensuring high light-fastness.
Implementation Method 1
wherein upon contact with the coagulation agent, the primary particles present in the first ink layer and in the second ink layer agglomerate such that secondary particles are formed in the first ink layer and in the second ink layer respectively
Data Source
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AI summary
The present invention relates to a method of printing comprising the steps of : a. providing a substrate, a reaction liquid comprising a coagulation agent and an ink set comprising a first ink composition comprising a first colorant and a second ink composition comprising a second colorant, different from the first colorant, wherein both the first colorant and the second colorant are dispersed as primary particles in the first ink composition and the second ink composition, respectively; b. applying the reaction liquid to a first surface of the substrate; c. printing a first layer of the first ink composition and a second ink layer of the second ink composition on the first surface of the substrate, wherein upon contact with the coagulation agent, the primary particles present in the first ink layer and in the second ink layer agglomerate such that secondary particles are formed in the first ink layer and in the second ink layer respectively, wherein the first ink layer obtains a first opacity and the second ink layer obtains a second opacity, wherein the ink layer obtaining the highest opacity is printed first. With such a method, the color gamut of an ink set comprising inks having a high light-fastness can be significantly improved. The invention further pertains to printed matter, printed with a method according to the present invention.