Inhomogeneity in cast or calendared sheets not only gives an unacceptable appearance but also can result in a significant degradation of mechanical properties.
The two basic sources for black spots either originate in the material or are introduced during processing. The polymer can also contain formulation defects that char instead of melting, becoming a dark speck surrounded by a gel.
When choosing a black masterbatch for cast or calendered sheet it is critical to choose a finely dispersed product with carefully controlled additives. This ensures easy processing, optimum optical properties (sheet smoothness, sheen and shine) together with good mechanical properties.
The Hubron range of black masterbatches and conductive compounds is used in a wide variety of food packaging, automotive and constructive applications.