Comparison of the color of spandex dyed with neutral dye and ordinary weak acid dye Comparison of the color of spandex dyed with neutral dye and ordinary weak acid dye
Neutral black dyeing spandex can reach very deep black, the same color depth as the relative yarn nylon, which can well solve the problem of spandex in the dyeing of deep color white. When the dyed color is deeper, the color fastness of the fabric to washing will be reduced.
The use of spandex coloring agent
Spandex coloring agent is a kind of ester containing amino, and spandex structure is similar, so it can be well adsorbed on the surface of spandex, at the same time, this kind of auxiliary contains a large number of amino, for acid dyes dyeing spandex to provide dyeing seat, can be very good to improve spandex and nylon with the same color. This kind of additive is usually used in the same bath with dyeing, with the dosage of 0.5%~2.0% (omf), without increasing or changing the dyeing process, which is more convenient and the dyeing effect is better.
The effect of spandex coloring agent on acid dyeing of spandex
When dyeing nylon/spandex fabrics with acid dyes, spandex coloring agent AN was added, when the dosage of AN was 2 g/L, the color difference between nylon and spandex was small, basically reaching the same color, and AN basically had no effect on the dyeing fastness of the fabrics, and the dyeing fastness was above grade
Spinning additives
In the secondary polymerization can be added to make spandex differentiated additives, such as additives to increase the dyeing performance of spandex, is now commonly used is diethylamine, the dosage is controlled at 2% or less, with the increase in the dosage of additives, the number of amino groups on the spandex is also increased, acid dyes on spandex to increase the dyeing rate, dyeing depth of the enhancement of the mechanism is shown below:
CN103483478A discloses a dyeing aid which can enhance the dyeing property of spandex during spandex spinning, which is obtained by the self-polymerization reaction of diethylaminoethyl methacrylate under the action of an initiator, azodiisobutyronitrile.201410365359.9 discloses a dyeing aid which enhances the dyeing property of spandex, which is formed by combining 4,4-diphenylmethane diisocyanate and 2 ,4-diphenylmethane diisocyanate mixed in dimethyl acetamide, and N-methyldiethanolamine and N,N-dimethylethanolamine mixture is added and stirred under certain conditions, and the dyeing aid is produced with a polyurethane structure, and its dyeing aid effective ingredient mass fraction is high.
Domestic improvement of spandex dyeability is basically through the addition of additives, including Yantai dyeable spandex, Xiaoxing ordinary spandex have added a certain amount of dyeing additives. The dyeing performance of spandex has a certain improvement, the improvement effect
Dyeing additives on acid dyes dyeing spandex effect
Change the spinning process of spandex
The real dyeable spandex is by changing the spandex spinning raw materials and spinning process, increase the number of spandex terminal amino acid or tertiary amino acid, improve the amount of acid dyes dyeing spandex, to achieve the purpose of spandex dyeing dark color, the mechanism is shown below:
This method needs to change the termination of the traditional Toyo spinning stock polymerization and increase the quantity of spandex terminal amino group. The dyed fabrics have very good dyeability and excellent color fastness, and compared with the color fastness to washing (grade 3) of conventional spandex dyed fabrics, dyeable spandex can reach grade 4.
The dyeing process of the real dyeable spandex is the same as that of nylon, which is favorable for production. Now the products that really improve the dyeing performance of spandex from spinning raw material are Xiaoxing H550 series and Huafeng S2308.
Prospect
The dyeing depth of spandex is mainly improved by increasing the number of terminal amino groups of spandex to improve the dyeing rate of acid dyes. Adding coloring agent and spinning additives during spinning has a certain deepening effect on spandex dyeing, but the deepening is limited and there is the problem of low color fastness. The real dyeable spandex is by changing the spinning raw materials and spinning process, can be a large number of spandex to improve the number of terminal amino acid, to achieve the same color depth with nylon, is the real meaning of dyeable. Now only a few spandex enterprises can do, in the stage of technical confidentiality. Therefore, how to increase the number of amino groups of spandex to achieve the real sense of dyeable spandex is the fundamental solution to the problem of spandex dyeing deep color, but also the direction of future research.
