Keratin-Based De-Inkable Inks for Recyclable Printed Substrates
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Solution Overview
Problem
Existing dye-based inks require harsh chemical treatments for de-inking, leading to environmental contamination and hinder recyclability of substrates like textiles, papers, and plastics.
Innovation Solution
A printing ink composition comprising keratin-based pigments with an average particle size of no more than 3000 nm, milled to partially unravel the helical structure, allowing easy de-inking with mild alkaline pH water solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dye-based inks are used for printing substrates, then colorfastness and lightfastness are achieved, but harsh chemical treatments are required for de-inking leading to environmental contamination
Solution Approach 1:
The patent changes the chemical composition parameters by replacing conventional dyes with keratin-based pigments derived from renewable sources. This parameter change allows the ink to maintain colorfastness while becoming soluble in mild alkaline conditions, eliminating the need for harsh de-inking chemicals and resolving the environmental contamination issue
Solution Approach 2:
The patent enables easy recovery and recycling of substrates by making the ink removable under mild conditions. The keratin-based pigment can be discarded from the substrate using simple aqueous alkaline solutions, allowing substrate reuse without the need for harsh chemical treatments that cause environmental contamination
2Reliability
If dye-based inks are used for printing substrates, then colorfastness is achieved, but recyclability of substrates is hindered
Solution Approach 1:
The patent changes the solubility parameter of the ink by using keratin-based pigments that are soluble in mild alkaline conditions. This allows the ink to remain fast on the substrate during normal use but become removable under specific alkaline conditions, enabling substrate recyclability while maintaining colorfastness
Solution Approach 2:
The patent creates a dynamic system where the ink's binding to the substrate is reversible. The keratin-based pigment binds under neutral conditions but releases under alkaline conditions, allowing the substrate to be recycled while maintaining colorfastness during normal handling and washing
3Ease of operation
If keratin-based pigments are milled to reduce particle size, then inkjet printing suitability is achieved, but production complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-milling the keratin-based pigments to the required nanoparticle size before ink formulation. This preliminary size reduction ensures compatibility with inkjet printing systems while allowing for standardized production processes that manage complexity through upfront preparation
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 keratin-based inks provide superior lightfastness and colorfastness, enabling easy de-inking and recyclability of substrates without harsh chemicals, with a high bio-renewable content.
Implementation Method 1
the one or more keratin-based pigment(s) has an average particle size of no more than 3000 nm... suitable for inkjet printing
Implementation Method 2
substrates that have been printed with the ink according to the invention can typically be de-inked using mild alkaline pH water solutions
Data Source
AI summary
The present invention relates to a printing ink composition comprising one or more keratin-based pigment(s) and water, wherein the one or more keratin-based pigment(s) has an average particle size of no more than 3000 nm.