What are the characteristics of disperse dyes?

Lifting power

Let's first look at the lifting power of disperse dyes, which is one of the important properties of disperse dyes. The lifting power is good, indicating that there is a good deep dyeing property. So what is the effect on dyeing? In fact, the lifting power of different varieties is very different. If you want to dye deep and dense colors, then the lifting power of the dye must be very high. However, in terms of actual production, the lifting power of the dye is directly linked to the concentration of the dye, which is the final color depth of the finished product. The change of this color density can be determined by experience. Of course, it is a better method to accurately determine the color depth value with the aid of an instrument.

Covering power

Let's take a look at the covering power of dyes. The covering power of disperse dyes on poor quality polyester is called covering power.

For example, under the same dyeing conditions, dyeing with various disperse dyes will appear in a variety of situations, with differences in each color profile, which means that the coverage of the dyes is very different. Covering power can be rated according to the gray standard, with serious color difference being level 1, and no color difference being level 5.

We can test the dyeing performance of polyester filaments. On the contrary, disperse dyes with poor coverage can be used to detect the quality of polyester fibers, and the fiber manufacturing process is unstable.

Dispersion stability

The dispersion stability of disperse dyes, disperse dyes will form very fine particles after being poured into water. However, the particle sizes of high-quality dye particles are very close, and a particle size distribution curve can be used for statistics. If the particle size distribution of the dye is not uniform, the dispersibility is also very unstable. If the particle size greatly exceeds the average value, then the phenomenon of recrystallization of the tiny particles will occur. When the number of recrystallized particles continues to increase, the dye will continue to precipitate, which will slowly deposit on the walls of the dyeing machine or on the fibers.

PH sensitivity

We all know the pH value, but do you know the sensitivity of the pH value? There are many kinds of disperse dyes, and the color spectrum is very wide. Dyes with different pH values will have different dyeing results, which will affect the depth of the color or the consequences of discoloration. The most stable state of disperse dyes is in a weak acid state, which is about pH 5. As a commercial dye, there are various pH values, some are neutral, and some are weakly alkaline. Before dyeing, the necessary step is to adjust the pH value with acetic acid. However, during the dyeing process, the pH value will rise at any time, and some weak acid must be added to keep the dye in a weak acid state.

Compatibility

What is compatibility? In the mass production of dyes, in order to reproduce the performance, we usually require the dyeing performance of the three primary color dyes to be similar, and the color difference of the dyes of the previous and subsequent batches should be kept consistent. It is necessary to keep the color difference between batches within a certain range, which is a problem of dye compatibility, which is also called compatibility. The compatibility of disperse dyes is also related to the depth of dyeing. The temperature of the dye should not be too high, generally not more than 80 degrees Celsius. Excessive temperature will affect the compatibility of dyes.