Simple Identification Method of Dyes on Cellulose Fiber

There are many chemical methods to identify dyes, and the general procedures are more complicated, time-consuming and labor-intensive. Therefore, this article introduces a simple method for identifying the types of dyes on cellulose fibers in printed and dyed textiles.

Principle

According to the dyeing principle of dyes to textiles, the commonly applicable dye types for common textile fabric ingredients are as follows:

Acrylic fiber-cationic dye

Nylon and protein fiber-acid dye

Polyester and other chemical fibers-disperse dyes

Cellulose fiber-direct, vulcanized, activated, reduced, coating

For blended or interwoven textiles, the types of dyes are used according to their components. For example, for polyester and cotton blends, the polyester component is disperse dyes, and the cotton component is performed separately using the corresponding dye types mentioned above, such as disperse/ Reactivity, dispersion/reduction process, etc.

Sampling and pretreatment

The key steps to identify the types of dyes on cellulose fibers are sampling and sample pretreatment. When taking the sample, the part of the same dye should be taken. If the sample contains several shades, each shade should be taken. If fiber identification is required, the type of fiber should be confirmed according to the FZ/TO1057 standard. If there are impurities, grease, and slurry on the sample taken that affect the experiment, it must be treated with detergent in 60-70℃ hot water for 15 minutes, washed and dried. If it is known that the sample has been finished with resin, use the following methods respectively.

1) Urine-formaldehyde resin is treated with 1% hydrochloric acid at 70-80℃ for 15min, washed and dried.

2) Acrylic resin can be treated with 50-100 times Erke reflow for 2-3h, and then taken out for washing and drying.

3) The silicone resin can be treated with 5g/L soap and 5g/L sodium carbonate 90cI=15min, washed and dried.