Operation points of dyeing process of high temperature and high pressure overflow jet dyeing machine

When dyeing, close the machine cover before heating up, and observe the running condition of the grey cloth in the machine from the glass sight hole at any time, and check whether there are abnormal sounds and phenomena in various parts of the machine. At 50～60℃, disperse dyes are dyed very slowly or hardly. When the temperature is above 80°C, the dyeing speed will increase. Therefore, the temperature rise between 80 and 130°C should not be too fast. Generally, graded heating and graded heat preservation are used to control the heating rate. This is especially important for Disperse Red 3B, Disperse Red Jade S-2GFL, and Disperse Scarlet S-BWFL, which are easy to cause color stains. When cooling down, the cooling rate should not be too fast to avoid defects such as wrinkle marks and chicken paw marks. Therefore, it is necessary to strictly control the cooling rate. Generally, the heating rate is based on the principle that the temperature change of the fabric does not exceed 1 to 1.5°C per revolution (referring to the main stage of temperature rise and fall). Generally, the dyeing bath ratio depends on the equipment model and structure, and should be 1:8～1:20. The principle of nozzle spray pressure control is: when the fabric is on the machine, the nozzle pressure can be larger, when it is running normally, the nozzle pressure can be smaller; the greater the thickness or weight of the fabric, the greater the nozzle pressure and the larger the nozzle diameter; generally The ratio of the diameter of the rope fabric to the diameter of the nozzle is 9:10. When cooling, it is strictly forbidden to inject cold water into the machine at high temperature to directly cool down.