The production process of polypropylene masterbatch is divided into three steps: grinding of pigment, mixing of pigment (dispersant, carrier) and granulation.

First, the grinding of the paint
The grinding of the pigment has the following methods:

1. Polymer protection method: the polymer dissolved in the solvent, and paint together, so that about 75% of the pigment particles are high polymer encapsulated to prevent flocculation.

2. Fatty acid and its metal salt Master pigment preparation method: first 12-16 carbon atoms fatty acid metal salts and 12 to 26 carbon atoms fatty acids and insoluble pigment dispersed into fine particles. The mixture is then compacted and granulated.

3. Dry grinding: Liao of the introduction of Hoechst company's patent production methods.

4. Wet grinding (conversion method): such as Beijing Yanshan Petrochemical Company introduced the Ciba Geigy company's patent production methods. The method is to paint the pigment, polyethylene wax, acetic acid solution and water together in a gravel mill for 20 hours. The ground material is pumped into the rotor, the NaOH is adjusted to pH 8 by adding NaOH in the trench. Adding white oil, heating high-speed stirring, the pigment from the water phase to the oil phase, the formation of particles size 0.1 ~ 3mm. Rinse the pigment particles with water and dry.

Second, the material mixture
The mixing of the materials is by heating the material (pigment, dispersant, carrier, antioxidant, ultraviolet absorber, etc.) in a kneader. Common kneading machine has a closed mixer, drum mixer and so on. Pneumatic transport can also be used for solid-phase mixing.

Third, extrusion granulation
Extrusion granulation, often using screw extruder. With the extensive use of exhaust twin screw extruders, this type of machine is usually accompanied by a vacuum exhaust system and a quick changeover device to improve the dispersion of pigment and