Dispersion / Bleaching

Disperging is used in recovered fiber systems for reducing unwanted contaminants to a size not interfering with downstream processing. Disperging also has the task of dislodging and reducing residual ink particles from the recovered fibers. This is a precondition for efficient deinking in flotation cells. In recovered fiber systems for brown papers (OCC), disperging must also improves fiber strength  in addition to reducing unwanted contaminants. In bleaching systems, dispergers are used for intense mixing of the bleaching agents with the fibers.

Bleaching improves the optical characteristics of the stock. The brightness is increased with the penetration of chemical additives by bleaching the fibers and colour stripping as well as moving the colour spectrum.