The development of denim clothing in my country has been for decades. Although it started late, it has developed quite rapidly. At present, denim clothing has basically entered a mature stage. With the development of the times, denim clothing is also constantly moving forward. At present, my country’s denim clothing production bases are mainly distributed in coastal areas and are gradually developing towards the central and western regions.
Currently, my country’s denim clothing is mainly yarn-dyed. Yarn is mainly dyed with a combined size dyeing machine, and some are dyed with a rope dyeing machine or a ring dyeing machine. The current development trend is towards rope dyeing. The reason is that the fastness of rope dyeing is better than that of starch dyeing. Let’s discuss the shade of dyeing.
Dyeing of denim yarn mainly uses indigo, sulfur dyes and vat dyes. There are mutual colors, and there are also those that use only one dye. There are various color combinations, and the development of craftsmanship has also reached a mature stage. But in recent years, many dyeing factories have encountered a very troublesome problem, which is the problem of color and light. Many dyeing factory masters say that the color of the boards brought by customers is cyan, but the color produced by themselves is reddish. Most of the popular colors currently on the market are cyan. Many masters try their best to adjust the desired color light. In fact, there are mainly the following aspects that affect the color and shading:
The shading problem of the dye itself
At present, there are quite a few dye manufacturers, both domestic and foreign. The quality of denim production is also unstable. The quality of the products produced by different manufacturers is different. Different batches produced by the same dyeing factory often produce different shades. In order to ensure the stability of the dyeing shade, before using the dye, the dyeing factory must conduct laboratory tests on each batch of newly purchased dyes and compare them with the previous ones to ensure that the shade is not far different and the quality is stable.
Auxiliary formulation issues
Dye auxiliary dosage It also has a great impact on color and light. For example, for indigo, caustic soda and insurance powder are generally used as reducing agents. The dosage of caustic soda and insurance powder has a great influence on the color of the dyed indigo. When the dosage of caustic soda is too large, the resulting color will be reddish; when the dosage of caustic soda is small, the resulting color will be cyan. The same goes for sulfur dyes and vat dyes.
When the amount of alkali is too large, the color light will tend to be red. Therefore, the dosage of additives must be strictly controlled when formulating. But the auxiliary should not be too small, because once the auxiliary is reduced, the color fastness of the dyed color will be very poor. The color light is “sub”. In addition, the quality of additives, like dyes, is also unstable. Each batch must be tested for quality when purchased, so as to ensure the stability of the color and light.
Some additives will also have the effect of changing the color and light
For example, some color fixing agents will produce a bluish light effect when added. Therefore, when choosing additives, you must understand their functions and effects clearly.
The influence of finishing
In fact, this reason cannot be said to be dyeing Affects the color light, because this is the impact on the color of the fabric after weaving and finishing. Generally, after weaving the cloth, if the cloth is mercerized, the color will turn red after mercerization. The alkali concentration and washing water during mercerization have a greater impact on the color and light. The alkali concentration is large and the color is reddish.
To sum up, there are actually many reasons that affect color and light, so we must slowly summarize them during production and operate Attention should be paid to adjusting the color and light according to the customer’s request. Make sure the color light is as close as possible to the customer’s board. In addition, there is another problem, that is, it is often difficult for many masters to distinguish between light and cyan. Generally, the light color does not look so red, but it looks cyan, and the dark color looks reddish. Especially indigo, obviously. Therefore, you must clearly distinguish the difference between light and green when making judgments. </p
