How to choose the chemical fiber dyestuff?

Dyestuff selection is an important part of process design, which not only affects the quality of dyed products but also directly relates to the product cost and economic efficiency. The selection of the dyestuff category should be based on fiber materials, color characteristics, fastness requirements, processing costs, equipment conditions, environmental requirements, and other factors. The dyeing process should be determined according to the type of dyestuff, production batch, equipment conditions, production costs, and other factors, and take into account the actual factory.

According to the nature of fiber raw materials

The raw material of the fabric is the most basic basis for the selection of dyestuff.

Blended or interwoven fabrics should be selected according to the composition and content of the fibers and the appropriate dyestuff and process, as far as possible to choose two common dyestuffs for fibers, so that the dyeing method and process are relatively simple.

If there is no suitable, two types of dyestuff can be selected to dye two different fibers but should consider the process adaptability of the two types of dyestuff.

Such as polyester and cotton blended products can choose soluble reduction dyes, and paint dyeing, can also choose to disperse / reactive, disperse / reductive dyes dyeing. For brocade/cotton interweaves, we can choose reactive dyeing, disperse/reactive, or weak acid/reactive dyeing.

According to the customer's sample request

Sample requirements generally include color difference, vividness, fastness to dyeing, product usage, etc. For certain fiber products, there are often many dyestuffs available, but not all of them can meet the customer's requirements.

For example, some dyestuffs can only dye a specific color; some dyestuffs may be suitable for dyeing deep and strong colors, while others are only suitable for dyeing light colors; some dyestuffs have good fastness, while others have poor fastness, etc.

This requires a good understanding of the application properties of each type of dyestuff, including their chromatography, vividness, dye fastness, price, etc., and then selecting the most suitable dyestuff according to the customer's requirements for color and fastness, etc.

According to the basic conditions of process implementation

Once the dyestuff variety has been selected, the dyeing process is basically determined. Therefore, when selecting dyestuffs, process designers must consider the implementation conditions of the process, such as the adaptability of equipment to the process, the technical skills of operators, and the production management level, to ensure that the selected dyestuff and process can be implemented smoothly. For example, the continuous rolling machines in some factories are not suitable for dyeing sulfide dyestuff (long wet steam is required after dipping and rolling the dye solution), soluble reduction dyestuff (acid color development dipping and rolling tanks need to be corrosion-resistant), and some factories do not have high-pressure confinement equipment, so they cannot implement high-temperature and high-pressure dyeing process for dispersing dyestuff.

According to the production cost

The main factors affecting production costs are the raw material costs of dyes and auxiliaries, the energy consumption during the dyeing process, and the management costs. The principle of dyestuff selection is to choose the dyestuff with low price, low energy consumption, easy operation, and low pollution as much as possible under the premise of meeting the customer's requirements for color and fastness of the product, which will help to reduce the production cost.