Magnetite Fe₃O₄ Toner Grade

Toner-grade magnetite must have a tightly controlled submicron particle size (0.15–0.25 µm d50) to achieve uniform distribution within the toner polymer matrix during melt-mixing, and to optimize optical density and magnetic response. Particles that are too large produce coarse toner images and uneven tribocharging; particles that are too small can cause agglomeration and poor dispersion in the binder resin.