Masterbatch is a granule in which a pigment or an additive is dispersed in concentrated form within a carrier polymer. It is mixed into the main raw material at a set ratio and disperses into the melt in the extruder. This allows clean, metered feeding instead of working directly with powder pigment.
Colour masterbatch gives the film colour or opacity. Additive masterbatches are used for functions such as slip, antistatic effect and ultraviolet resistance. It is important for the carrier polymer to be compatible with the main raw material; for polyethylene film, a polyethylene-based masterbatch is usually chosen. The mixing ratio is set according to the desired effect and the producer’s recommendation.