An efficient bleaching process is key.
Kraft pulping produces strong pulp that typically requires further processing — bleaching — to provide acceptable brightness. The bleaching process removes the lignin (source of colour) which remains after the digester cooking process. This process uses large quantities of expensive bleaching chemicals (usually ClO2) and presents raw material and waste disposal challenges. pH measurement in this area optimizes the efficiency of the bleaching process and lowers bleach consumption, discharge, and associated costs.