Mini-Encyclopedia of Papermaking Wet-End Chemistry
Additives and Ingredients, their Composition, Functions, Strategies for Use


Composition: The major component of "white pitch" sometimes observed in paper machine systems is latex binder from recycled coated broke. This can include styrene-butadiene resin (SBR), acrylic resins, and polyvinylacetate latex components. It also can contain the associated coating pigments, including clay, plastic pigments, calcium carbonate, and titanium dioxide. White pitch problems are often made more difficult due to mixing with wood resins, defoamer components, and other tacky materials in the furnish.

Function: White pitch can cause reduced papermaking efficiency due to felt filling and down-time required to clean up equipment.



Coated broke treatment   Schematic explanation of why treatment of coated broke with a highly cationic polyelectrolyte can decrease pitch deposit problems


