Pulping

Fibers from virgin pulp, recovered paper or paper machine broke are pulped with water to form a suspension in the  “Pulping” process step. An optimal pulping technology can be selected, depending on the type of furnish, production output and the contaminant included in the furnish. Pulping systems for recovered paper not only break down the fiber material, but also remove large non-recyclable components (rejects). It is, therefore, important to balance the main pulping parameters such as stock consistency, temperature, mechanical attrition, dwell time and chemical additives so that trash components are not broken down unnecessarily and, thus, made more difficult to screen later in the process. Pulping of recovered paper also has to consider the various parameters for downstream ink removal if used for graphical paper products.