Stock Prep/Refining

Stock preparation tanksOur pilot plant is fully equipped to perform all major areas of stock preparation, including size reduction, repulping, cleaning, screening, and refining.  We can take virtually any raw material – from wood, agricultural residuals, plant, or synthetic source – and produce a wide range of products.

Refining is a critical operation in which the inherent properties of the paper are developed. The PDC has three double-disc refiners (one 13-inch and two 20-inch), one  20″ single-disc refiner, and two conical refiners. All refiners are equipped with variable-speed motors. The refiner loop is connected to several tanks for refining studies in recirculation or single-pass mode. The refiners allow for a range of refining prior to papermaking as well as for a comparison of the benefits provided by each type of machine.

Pulp impurities arising from wood or external sources can be separated based on size, shape, specific gravity, and specific surface differences. Centrifugal cleaners are arranged to allow for performance evaluation under typical operating conditions and a pressure screen can remove oversized foreign bodies. Our Centri-sorter can be operated under a wide variety of conditions.

Stock Preparation Equipment

  • Hydrapulpers (2) –  pilot-scale
  • Stock tanks (5) – interconnected and agitated
  • Disc refiners – 13” DD,  20” SD, and (2) 20″/24″ DD
  • Conical refiners – PRO1 and Conflo
  • Ink removal cleaner
  • Combination cleaner
  • Forward & reverse flow cleaners
  • Centrifugal screen
  • Thickening screen


  • Refiner optimization
  • Series versus parallel refining configuration
  • Independent control of specific energy and intensity
  • Cleaner optimization

To begin working with us, visit our Working with the PDC page.