Foam Dyeing of Cationized Cellulosic Substrates With Less Water
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Solution Overview
Problem
Current dyeing processes for cellulosic materials, such as cotton, are inefficient in terms of energy usage, chemical consumption, and waste generation, with limited dye transfer efficiency and uniformity, and require extensive water and salt usage.
Innovation Solution
A method involving cationization of the cellulosic substrate followed by foam-based dye application using a foam generator and applicator head with a parabolic distribution chamber, eliminating the need for scouring steps and reducing water and energy consumption, where the cationized substrate is then steamed to enhance dye bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional piece dyeing, continuous dyeing, or yarn dyeing methods are used, then cellulosic materials can be dyed, but large amounts of energy, chemicals, and salt are required
Solution Approach 1:
The invention changes the physical state of the dye application from liquid to foam, and modifies the fiber surface charge through cationization. These parameter changes enable the dye to be applied more efficiently with reduced energy input, as the foam structure provides better dye retention and the cationized fiber surface enhances dye uptake, eliminating the need for extensive heating and chemical additives used in traditional methods.
Solution Approach 2:
The foam acts as an intermediary carrier between the dye solution and the fiber. The foam structure allows for controlled dye release and improved contact with the fiber surface, enabling more efficient dye transfer with reduced energy and chemical requirements compared to direct liquid dye application.
2Quantity of substance
If traditional dyeing processes are used, then color can be applied to cellulosic fabrics, but dye application uniformity is problematic
Solution Approach 1:
The invention changes the physical state of dye application from liquid to foam, which provides better distribution control. The foam structure ensures more uniform contact with the fiber surface, and the cationization process creates consistent positive charges throughout the fiber, leading to uniform dye uptake and eliminating the uneven dye application problems of traditional methods.
Solution Approach 2:
The cationization process modifies the local surface properties of the fiber by introducing positive charges at the fiber surface. This local modification creates uniform attraction sites for the dye molecules throughout the fabric, ensuring consistent and uniform dye distribution across the entire material.
3Quantity of substance
If traditional dyeing methods are used, then cellulosic materials can be dyed, but extensive water and salt usage creates waste water containing residual dyes, chemicals, and salts
Solution Approach 1:
The invention changes the dye application from liquid to foam form, which significantly reduces water consumption. The foam structure contains the dye in a minimal amount of liquid, and the cationized fiber surface ensures high dye uptake efficiency. This eliminates the need for extensive water rinsing and chemical neutralization steps, thereby preventing waste water pollution from residual dyes, chemicals, and salts.
Solution Approach 2:
The invention converts the traditionally harmful excess water and chemical usage into a beneficial foam structure that delivers dye efficiently with minimal liquid. The foam formulation and cationization process transform the waste-generating liquid dye bath into a concentrated, efficient delivery system that leaves no harmful residues.
4Quantity of substance
If traditional dyeing processes are used, then cellulosic substrates can be dyed, but a significant amount of chemicals and salts must be added to the dye bath
Solution Approach 1:
The invention changes the chemical state of the fiber surface through cationization, introducing positive charges that directly attract and bind the dye molecules. This chemical modification eliminates the need for adding salts and other chemicals to the dye bath, as the cationized fiber itself provides the necessary chemical environment for efficient dye uptake, thereby simplifying the overall process.
Solution Approach 2:
The foam acts as a chemical intermediary that delivers the dye in a pre-formulated, optimized state. The foam structure and cationized fiber work together as a coordinated system, eliminating the need for additional chemical additives and simplifying the process by removing the step of chemical formulation and adjustment.
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 significantly reduces dye usage, energy consumption, water usage, and waste generation, while improving dye uniformity and washfastness, and eliminates the need for salt and scouring steps, resulting in cost savings and enhanced colorfastness.
Implementation Method 1
a foam composition including at least one dye is applied to a cellulosic substrate... the foam composition is generated with a foam generator to which air and liquid dyestuff is fed
Implementation Method 2
a step of cationizing a cellulosic substrate followed by dyeing the substrate
Implementation Method 3
the freshly dyed cellulosic substrate is subjected to a steaming step in which the dyed cellulosic substrate is conveyed through a steamer unit such that the dyed cellulosic substrate is contacted with steam
Data Source
AI summary
The present invention is related to methods for dyeing a traveling cellulosic substrate. The methods include steps of cationizing a cellulosic substrate followed by applying foam including one or more dyes to the cationized cellulosic substrate.