Printing on a textile
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Solution Overview
Problem
Current textile printing methods, primarily analog screen printing, face limitations in multi-color printing and washfastness, with digital inkjet printing requiring pre- and post-treatment processes for reactive inks and acid dyes, whereas pigmented inks often need post-treatment for washfastness, which can be inconvenient.
Innovation Solution
A thermal inkjet ink formulation using a styrene acrylic resin as a single dispersant and binder, with a high acid number and low molecular weight, is used to print on cotton fabrics without a post-treatment process, achieving washfastness and jettability by incorporating a pigment, co-solvent, anti-kogation agent, anti-decel agent, surfactant, biocide, and pH adjuster, along with water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reactive inks or acid dyes are used for digital inkjet printing on textiles, then color fastness can be achieved, but pre- and post-treatment processes are required which increase process complexity and time
Solution Approach 1:
The patent combines the binder resin and dispersant functions into a single styrene acrylic resin compound. This unified compound performs multiple functions simultaneously: it binds the pigment to the textile substrate and disperses the pigment particles in the ink vehicle, eliminating the need for separate binder and dispersant components and simplifying the overall ink formulation and application process
Solution Approach 2:
The styrene acrylic resin is pre-formulated with specific functional groups and molecular weight characteristics that enable it to provide both binding and dispersing capabilities in advance. The resin is prepared with acid numbers and molecular weights optimized beforehand to achieve washfastness without requiring additional post-treatment steps
2Productivity
If pigmented inks are used for digital inkjet printing on textiles, then the ink can be jetted effectively, but post-treatment processes are needed to achieve washfastness
Solution Approach 1:
The styrene acrylic resin compound serves multiple functions simultaneously: it acts as a binder to attach pigment to the textile, as a dispersant to maintain pigment stability in the ink vehicle, and as a washing fastness agent. This multi-functional approach eliminates the need for separate post-treatment processes that would otherwise be required to achieve washfastness
3Stability of the object's composition
If conventional binder resins are used in thermal inkjet inks, then pigment dispersion is achieved, but washfastness is insufficient without post-treatment curing
Solution Approach 1:
The patent specifies particular parameter ranges for the styrene acrylic resin including acid numbers of 50-200 mg KOH/g and weight average molecular weights of 5,000-50,000. These parameter changes optimize the resin's ability to provide both dispersion and washfastness properties, with the acid number controlling the resin's reactivity and bonding characteristics while the molecular weight affects film formation and durability
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 thermal inkjet ink provides excellent washfastness, measured by optical density stability and ΔE, and good jettability performance, eliminating the need for post-treatment processes while maintaining stability over time, even after multiple wash cycles.
Implementation Method 1
Current inkjet printing technology involves forcing the ink drops through small nozzles by thermal ejection, piezoelectric pressure or oscillation onto the surface of the media
Implementation Method 2
a binder resin, the binder resin being a styrene acrylic resin having an acid number greater than 100 mg KOH/g and a weight average molecular weight less than 50,000
Implementation Method 3
a single dispersant and binder resin, the single dispersant and binder resin being a styrene acrylic resin
Data Source
Figure 1~2
Figure 3
AI summary
In an example of a method for printing on a textile, a print is generated by thermal inkjet printing a thermal inkjet ink on a cotton fabric. The thermal inkjet ink consists of a pigment, a single dispersant and binder resin, a vehicle, and a balance of water. The single dispersant and binder resin is a styrene acrylic resin having an acid number greater than 100 mg KOH/g and a weight average molecular weight less than 50,000. The vehicle includes a co-solvent, an anti-kogation agent, a humectant, a surfactant, a biocide, or combinations thereof. The print is generated without a post-printing curing process.