Ammonia Textile Dyeing with Humidity Control and Shrinkage Constraint
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Solution Overview
Problem
Industrial dyeing methods using liquid ammonia face challenges in achieving uniform dye fixation and color consistency due to non-homogeneous humidity distribution and irregular shrinkages in textiles, leading to suboptimal results when scaling up from small samples to large quantities.
Innovation Solution
A method and apparatus for dyeing textiles using an ammonia solution with dyes, where the textile material is pre-adjusted to a uniform humidity level, impregnated with the solution, and then constrained to prevent shrinkage, allowing for 80-100% pick-up and subsequent evaporation, followed by steaming to fix the dyes, and optionally washing to remove excess dye, ensuring uniform dye distribution and high yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If textile material is dyed with ammonia solution in industrial applications, then dyeing can be performed on large quantities of textiles, but non-homogeneous humidity distribution and irregular shrinkages cause non-uniform dyeing and insufficient dye fixation
Solution Approach 1:
The textile material is pre-treated to adjust humidity distribution to a predetermined value before dyeing. This preliminary action ensures that the fabric has uniform moisture content, which prevents non-homogeneous dye absorption and shrinkage during the subsequent ammonia solution treatment, thereby achieving uniform dyeing across the entire textile surface.
Solution Approach 2:
The invention controls and adjusts the humidity parameter of the textile material to a specific predetermined value before dyeing. By optimizing this physical parameter, the fabric becomes more receptive to the ammonia solution and dye, ensuring uniform penetration and fixation throughout the textile, thus resolving the non-uniformity issue while maintaining high productivity.
2Loss of substance
If liquid ammonia is used as solvent for dyes, then water consumption and auxiliary chemicals are eliminated, but the method cannot be applied industrially for dyeing big quantities of textiles
Solution Approach 1:
The textile material undergoes preliminary humidity adjustment before being subjected to the ammonia solution treatment. This pre-treatment step prepares the fabric to optimally receive the dye solution, ensuring uniform and efficient dye uptake, which enables the process to be scaled up for industrial production while maintaining the environmental benefits of reduced water and chemical usage.
Solution Approach 2:
By controlling the humidity parameter of the textile before dyeing, the invention optimizes the fabric's readiness to absorb the ammonia solution. This parameter control ensures that even large quantities of textiles can be processed efficiently with consistent results, thereby enabling industrial-scale application while preserving the advantages of minimal water and auxiliary chemical consumption.
3Manufacturing precision
If textile material is impregnated with liquid ammonia for extended periods, then cellulose conversion from type I to type III increases, but processing time increases
Solution Approach 1:
The invention adjusts the humidity parameter of the textile material to a predetermined optimal value before impregnation with liquid ammonia. This pre-optimization of the fabric's moisture content enhances its reactivity and accessibility to the ammonia solution, thereby accelerating the cellulose transformation process from type I to type III and reducing the required impregnation time while still achieving the desired structural changes.
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 ensures uniform dyeing, high dye fixation, reduced chemical and water usage, and zero pollution, with ammonia being recyclable, resulting in brilliant colors and improved fabric properties while preventing unwanted shrinkage and pollution.
Implementation Method 1
the small molecule of liquid ammonia does not only penetrate into the amorphous zones, but also into the crystalline zones of the cellulose, breaking the hydrogen bonds so that the fiber can swell entirely
Implementation Method 2
ammonia exerts a swelling effect on the cellulose fibers, with a crystalline orientation of the cellulose
Implementation Method 3
In the subsequent evaporation stage, with the creation of new hydrogen bonds, the cellulose which was originally type I transforms, in a certain percentage, into type III cellulose
Implementation Method 4
the textile material being kept mechanically constrained to prevent unwanted shrinkage
Implementation Method 5
squeezing out the excess ammonia solution from the textile material, still kept mechanically constrained, in order to obtain an adjustable pick-up of about 80 - 100%
Data Source
Figure 1
AI summary
Method for dyeing and simultaneously finishing textile material (14) with an ammonia solution (13) containing dyes dissolved therein. The method comprises the following steps: - preparing the ammonia solution (13) containing the dyes and sending this ammonia solution to a machine (11) for processing the textile material (14); - adjusting the percentage of water present in the textile material (14) before said textile material (14) enters into the processing machine (11) so that the overall percentage of water contained in the ammonia solution (13) and the percentage of water present in the textile fibers is at maximum 20% with respect to the total weight of the solution; - entry of the textile material (14) into the processing machine (11) through safety seals (15); - impregnating the textile material (14) with the ammonia solution (13) for at least a few seconds, the textile material (14) being kept mechanically constrained between at least an entrance tensioner element (19) and an exit tensioner element (23); - squeezing out the excess ammonia from the textile material (14), still kept mechanically constrained, in order to obtain an adjustable pick-up of about 80 - 100% with respect to the dry weight of the textile material (14); - evaporation of the ammonia from the textile material (14) inside the processing machine (11); - exit of the textile material (14), dyed and dried, from the processing machine (11) through safety seals (115).