Textile Dyeing Dyebath Using Borohydride-Bisulfite Reduction
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Solution Overview
Problem
Existing methods for dyeing textiles with reducible dyes using sodium bisulfite and sodium borohydride require harsh conditions of high pH and temperature, which are unsafe and detrimental to the textiles, and commercially, hydrosulfite is used under similar conditions, posing safety and efficiency concerns.
Innovation Solution
A method involving a dyebath composed of water, sodium bisulfite, sodium borohydride, and reducible dyes, with a pH range of 9 to 11, where dithionite ions are produced, allowing for efficient dye reduction at milder conditions, using sodium bisulfite and sodium borohydride in specific ratios, and optionally including additional hydroxide, to create a safer and more efficient dyeing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high pH and high temperature conditions are used for dyeing textiles with reducible dyes, then dye reduction efficiency is improved, but safety and textile quality deteriorate
Solution Approach 1:
The invention changes the chemical parameters of the dyebath by using a mixed reducing agent system (hydrosulfite and borohydride) that enables effective dye reduction at lower pH (9-11) and lower temperature (below 80°C) compared to conventional high pH-high temperature processes, thereby improving safety and textile quality while maintaining dye reduction efficiency
Solution Approach 2:
The invention employs a composite reducing agent system combining hydrosulfite and borohydride compounds in specific ratios (1:4 to 4:1 weight ratios). This composite approach leverages the complementary properties of both reducing agents to achieve effective dye reduction under milder conditions than either agent could achieve alone
2Ease of manufacture
If hydrosulfite is used for dye reduction under high pH conditions, then dyeing process is simplified, but chemical usage and safety risks increase
Solution Approach 1:
The invention optimizes the pH parameter range (9-11) and temperature parameters to enable effective dye reduction with reduced chemical consumption. The mixed reducing agent system achieves better utilization efficiency, reducing the total amount of chemical agents required compared to conventional single-agent high pH processes
Solution Approach 2:
By combining hydrosulfite and borohydride in a composite reducing agent system, the invention achieves synergistic effects that improve dye reduction efficiency per unit of chemical used, thereby reducing overall chemical consumption while maintaining process simplicity
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 method achieves efficient dye reduction at milder conditions, ensuring safer textile processing and maintaining colorfastness and washfastness of the dye, with results comparable to hydrosulfite-based dyeing but with reduced chemical usage and improved safety.
Implementation Method 1
reduction of the dyes with sodium bisulfite and sodium borohydride
Data Source
AI summary
A method for dyeing textiles with reducible dyes in the presence of borohydride and bisulfite.