Dye granulation method

1、 Wet granulation

Add the dye filter cake, auxiliary agent and adhesive into the blender for full mixing, and then enter the extruder granulator to extrude cylindrical particles with a length of 0.5~2mm through a sieve with a hole diameter of about 1mm. Then, it is dried at low temperature to obtain cylindrical particles. This method is applicable to the granulation of water-soluble dyes such as reactive dyes. The adhesives added in the formula mainly include sodium alginate, carboxymethyl cellulose, hydroxypropyl cellulose, sucrose, sodium acrylate, polyvinylpyrrolidone and other water-soluble polymer compounds. The amount of binder should not be too much, generally about 1%~5% of the dye amount.

2、 High-frequency granulation

High frequency granulation is to put materials into the granulator. The bottom of the granulator is equipped with paddle type stirring, and the side wall of the granulator is equipped with a stirring device that can generate high-frequency oscillation. The bottom can spray adhesive to powder materials. After stirring, the adhesive and dye are combined, and the side wall stirring device plays a strengthening role in granulation. The particles obtained by this method have good sphericity and uniform particles. The particle size can be changed by changing the shape of the mixing device and the vibration frequency.

3、 Melting granulation

Fully mix the dye with the auxiliaries. The commonly used auxiliaries are water-soluble compounds with a melting point of 50~200 ℃, such as urea, sugar and polyol, to form a melt. After the solution is formed, it is sent to a device that can be dispersed into droplets, such as a multi hole high-speed rotating centrifugal nozzle, for cooling and forming. The particles obtained by this method are solid particles with considerable mechanical strength, and the damage rate of particles caused by transportation and storage is small.

4、 Dry granulation

Dry granulation is to use fluidization technology to spray dry powder dye into the fluidized bed, and spray adhesive into the fluidized bed through the converted nozzle. The fluidized powder dye is fully contacted with the adhesive droplets and bonded together, and the particles are formed after low-temperature drying. This method can be used for continuous production. There are fixed dry powder granulation equipment abroad.

5、 Spray granulation

Spray granulation is a very widely used granulation method in many dye factories. spray Zari is used to make particles of dyes while drying, especially suitable for drying granulation of heat sensitive and low viscosity dyes. According to the equipment form, spray granulation can be divided into pressure type, centrifugal type, spray fluidization type, spray belt type and other forms. Different spray granulation methods lead to different product particles.