Lignin-Based Textile Dyeing Method for Waste Utilization and Fastness
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Solution Overview
Problem
The textile industry faces challenges in utilizing lignin as a dye stuff for textiles, as it has not been employed effectively as a colorant despite its availability and beneficial properties, leading to lignin being considered waste in paper and bio-fuel industries.
Innovation Solution
A method involving an aqueous solution with lignin at 10-30% weight is used to dye cellulosic fibers, where the fabric is passed through a dye bath multiple times to achieve 90-100% lignin pickup, followed by drying, potentially incorporating binders, softeners, and pretreatments to enhance dyeing and properties like bacteriostatic and anti-fungal effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If lignin is used as a dye stuff for textiles, then waste utilization is improved and environmental sustainability is enhanced, but the textile industry lacks established processes and expertise for effective lignin dyeing
Solution Approach 1:
The patent applies parameter changes by optimizing the lignin concentration in the dye bath (10-30% by weight) and controlling the dyeing process parameters such as temperature, time, and number of dips. This transforms the previously ineffective lignin waste into an effective dyeing agent by adjusting the concentration and process conditions to achieve 90-100% lignin pickup on fabric.
Solution Approach 2:
The patent uses binders as an intermediary substance to facilitate the bonding between lignin and fabric. The binders help transfer and fix the lignin dye onto the textile fibers, overcoming the lack of established dyeing processes and making the waste lignin effectively usable for textile coloring.
2Productivity
If high concentration of lignin (10-30% by weight) is used in dye bath, then dyeing efficiency and lignin pickup (90-100%) are improved, but the complexity of dye bath formulation and process control increases
Solution Approach 1:
The patent achieves high dyeing efficiency by optimizing key parameters: lignin concentration (10-30% by weight), number of dips (multiple passes), and process temperature. These parameter changes enable 90-100% lignin pickup while maintaining manageable process complexity through systematic optimization.
Solution Approach 2:
The patent employs periodic action by using multiple dips of the fabric through the dye bath rather than a single prolonged exposure. This periodic immersion approach improves dyeing efficiency and ensures thorough lignin pickup while simplifying the overall process control compared to continuous processing.
3Reliability
If multiple dips through dye bath are performed, then lignin pickup reaches 90-100% and color fastness is improved, but the processing time and number of operations increase
Solution Approach 1:
The patent uses periodic action through multiple short dips of the fabric through the dye bath, which achieves superior lignin pickup (90-100%) and wash fastness. This periodic approach is more efficient than a single long-duration treatment, as it allows better penetration and fixation of lignin across multiple passes.
Solution Approach 2:
The patent applies preliminary action by preparing the fabric through pre-treatment steps before the actual dyeing process. This includes washing to remove sizing and impurities, and optional cationic or anionic pretreatment to enhance lignin uptake, thereby improving final color fastness and reducing the time needed during the dyeing stage itself.
4Manufacturing precision
If fabric is pre-treated with cationic or anionic agents, then lignin uptake and dyeing uniformity are improved, but the number of process steps and chemical usage increases
Solution Approach 1:
The patent applies preliminary action through fabric pre-treatment with cationic or anionic agents before dyeing. This pre-treatment modifies the fabric surface to enhance lignin uptake and ensure uniform dyeing across the entire fabric. The preliminary preparation step creates optimal conditions for subsequent lignin application, improving manufacturing precision.
Solution Approach 2:
The patent uses parameter changes by adjusting the fabric's surface properties through chemical pretreatment. By modifying the fabric's electrical charge and surface chemistry with cationic or anionic agents, the patent optimizes the interaction between fabric and lignin, achieving uniform dyeing distribution and high lignin pickup efficiency.
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 method produces lignin-dyed fabrics with good wash fastness and bacteriostatic/anti-fungal properties, suitable for various cellulosic fibers, demonstrating lignin's potential as a renewable and effective textile dye.
Implementation Method 1
passing a fabric through the first dye bath such that the fabric picks up lignin to dye the fabric
Implementation Method 2
drying the dyed fabric after passing the dyed fabric through the second dye bath
Data Source
AI summary
Dye baths including an aqueous solution including lignin in a range of 10% to 30% by weight of the aqueous solution are described. In addition, methods of dyeing fibers, yarns, textiles, or garments with an aqueous solution including 10% to 30% lignin by weight is disclosed. Further, methods of dyeing a fabric including preparing a first dye bath including an aqueous solution having lignin in a range of 10% to 30% by weight of the aqueous solution and passing a fabric through the first dye bath such that the fabric pics up lignin to dye the fabric is disclosed.