hydrapulper

A hydrapulper is a high-shear pulping device used in paper recycling to defiber and disintegrate shredded or baled paper into a slurry of fibers. It is typically a sealed chamber equipped with a rotor and stator that creates strong turbulence when operated with water. Paper stock is fed into the chamber, where the rotor’s motion and the water flow mechanically separate fibers, loosen adhesives and coatings, and begin the removal of contaminants. The resulting pulp is then directed to screening, cleaning, and deinking stages as part of a recycling process.

Design and operation details vary, but most hydrapulpers rely on a controlled combination of mechanical shear and water flow. Some units operate at higher fiber solids (high-consistency pulpers) to reduce water use and increase throughput, while low-consistency pulpers use more water for gentler handling and improved separation of certain contaminants. The system often includes separation screens or subsequent cleaners to remove metal, plastics, and other debris before fiber processing advances to refining or papermaking stages.

Applications and use cases include pulping mixed paper streams, old corrugated containers (OCC), and other recovered papers in deinking and recycling lines. Hydrapulpers are valued for rapid defibration and compact footprint but require attention to wear on rotors and stators, screen fouling, and energy use. Proper feeding, control of slurry consistency, and downstream screening are important to optimize fiber yield and process efficiency.