Pad-steam cationization of textiles
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Solution Overview
Problem
Traditional dyeing processes for cotton-based textiles require significant water, energy, and chemicals, and result in less dye uptake due to the neutral charge of cotton fibers, leading to inefficient coloration and increased waste production.
Innovation Solution
A method and system for cationizing cotton textiles using an aqueous solution with an alkali metal hydroxide and a halogenated cationizing agent capable of generating two epoxide groups, followed by steam treatment at temperatures between 100°C and 110°C for a short duration, minimizing waste and energy consumption while enhancing dye association.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional salt and alkali treatment is used to associate dye with cotton fiber, then dye uptake is improved, but water consumption and chemical usage increase significantly
Solution Approach 1:
The invention changes the surface charge parameter of cotton fiber from neutral/negative to positive through cationization treatment. This parameter change allows direct electrostatic attraction between the positively charged fiber surface and negatively charged dye molecules, eliminating the need for salt and alkali chemicals traditionally used to facilitate dye association.
Solution Approach 2:
The invention extracts and eliminates the need for salt and alkali chemicals from the dyeing process by directly modifying the cotton fiber surface charge. The cationization process removes the dependency on these auxiliary chemicals, simplifying the dyeing formulation and reducing chemical consumption.
2Loss of substance
If batch treatment with base and cationizing agent at low temperature is used to minimize waste product formation, then reaction efficiency is improved, but processing time becomes excessively long
Solution Approach 1:
The invention utilizes the phase transition from liquid to vapor by introducing steam into the treatment system. The steam provides both heat and a controlled atmosphere that accelerates the cationization reaction while minimizing hydrolysis of the epoxide group. This phase change enables the process to achieve rapid reaction rates without excessive waste product formation.
Solution Approach 2:
The invention changes the temperature parameter from low temperature batch treatment to elevated temperature steam treatment. This parameter change, combined with the steam atmosphere, dramatically reduces processing time from hours to minutes while maintaining low waste product formation through the controlled reaction environment.
3Productivity
If steam treatment at high temperature is used to accelerate cationization reaction, then processing speed is improved, but energy consumption increases
Solution Approach 1:
The invention uses steam (a gas phase medium) to transfer energy and facilitate the cationization reaction. The steam atmosphere provides efficient heat transfer and creates a controlled reaction environment that accelerates the process while the condensation of steam releases latent heat that can be utilized, improving energy efficiency compared to conventional heating methods.
4Quantity of substance
If cationic reagents are used to modify cotton fibers and provide permanent positive charge, then dye association is improved, but chemical usage increases
Solution Approach 1:
The invention changes the surface charge parameter of cotton fiber from neutral/negative to positive through cationization treatment. This parameter change allows direct electrostatic attraction between the positively charged fiber surface and negatively charged dye molecules, eliminating the need for salt and alkali chemicals traditionally used to facilitate dye association.
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 process achieves efficient cationization of cotton textiles with improved dye uptake and color fastness, reducing chemical and water usage, and enabling the production of textiles with bright, bold, and long-lasting colors.
Implementation Method 1
The textile is then treated in an environment with steam at a temperature(s) that is greater than 100° C. but less than 110° C. for a period of time in the range of 1 min to 10 min to react the cationizing agent with the textile.
Implementation Method 2
the epoxide group of this compound can react with a deprotonated hydroxyl group of cellulose, thereby covalently linking the cationic ammonium chloride group to the cellulose backbone through an ther linkage.
Implementation Method 3
there is a competing reaction with water molecules which results in the epoxide group of EPTAC being hydrolyzed, and generating 2,3-dihydroxypropyl trimethyl ammonium chloride (2,3-DHTAC), which is a waste product.
Data Source
AI summary
Described are methods and systems for cationizing and dyeing a natural fiber-containing textile. The method includes a step of steam treating a textile padded with a base and cationizing agent in a defined temperature range (greater than 100° C. to less than 110° C.) and for a defined time period (1 min to 10 min). The cationizing agent in the presence of the base is capable of generating two epoxide groups. The cationization step in the presence of steam using the halogenated catonization agent of the invention facilitates improved dyeing.