Black masterbatch is a kind of masterbatch, but its status is somewhat different from other masterbatch. Black masterbatch is the most commonly used color masterbatch in plastic processing, and it is also the largest consumption one. Black masterbatch is a plastic colorant that is well dispersed with a high proportion of pigments or additives and thermoplastic resin. The selected resin has a good wetting and dispersing effect on the colorant, and has good compatibility with the material to be colored Properties, namely: pigment + carrier + additive = masterbatch.
Black masterbatch is widely used in plastic processing industries, such as injection molding, extrusion molding and blow molding. In real life, it is widely used in the injection molding of automotive plastic parts, the extrusion molding of plastic pipes, and the production of agricultural mulch and geotechnical materials.
(1) Ink method: As the name suggests, it is a production method that uses ink color paste in the production of masterbatch, that is, through three-roll grinding, the surface of the pigment is coated with a low-molecular protective layer. The ground fine color paste is mixed with the carrier resin, and then plasticized by a two-roll plastic mill (also called a two-roll mill), and finally pelletized by a single-screw or twin-screw extruder.
(2) Washing method: the pigment, water and dispersant are sand-milled to make the pigment particles smaller than 1μm, and the pigment is transferred into the oil phase by the phase transfer method, and then dried to obtain the masterbatch. An organic solvent and a corresponding solvent recovery device are required for phase inversion.
(3) Kneading method: After blending the pigment and the oily carrier, the pigment is washed away from the water phase into the oil phase through kneading by using the characteristics of the pigment's lipophilicity. At the same time, the oily carrier coats the surface of the pigment to stabilize the dispersion of the pigment and prevent the pigment from agglomerating.