Factors affecting dyeing with high temperature and high pressure dyeing machine

1. Temperature

Temperature is the key factor of high temperature and high pressure dyeing machine. Increasing the temperature can increase the dye uptake of disperse dyes by%. However, when the temperature is above 130 ℃, the dye uptake of most disperse dyes will no longer increase significantly. High temperature will cause hydrolysis of polyester ester bond, which will reduce the elasticity and strength of the fiber, and the color light is poor. Therefore, high temperature and high pressure dyeing is generally limited to no more than 145 degrees. Generally, the dyeing temperature is controlled between 125-130 degrees. At this temperature, dyeing not only has good levelness and high color yield, but also the pH value of the dyeing bath is controlled within the weak acid range of 5-6. Most disperse dyes are quite stable, so the color is very bright. In order to make the dye adsorbed by polyester evenly, the heating rate must be strictly controlled. When the temperature rises to the specified temperature, the dye shall be kept warm for a period of time to ensure that the dye is fully diffused and penetrated. The heat preservation dyeing time is generally 30-60 minutes, light color can be shorter, dark color can be longer. After dyeing, the temperature should not be lowered too fast, otherwise it will affect the hand feel and cause creases.

2. PH value

Many disperse dyes will hydrolyze under high temperature and alkaline conditions, so high temperature and high pressure dyeing bath is suitable for controlling acidic conditions,

3. Application of additives

In high temperature and high pressure dyeing, in order to make the dye Disperse stably in the dyeing bath, and to obtain the leveling effect, an appropriate amount of dispersant and leveling agent can be added to the dyeing bath.