Defibrator
The defibrator is a pulping refiner that consists of a rotating plate (rotator) and a static plate (stator), each with radial grooves that get smaller as they get closer to the circumference. Woodchips are fed into the centre and get broken down as the centrifugal force pushes them toward the outside of the plates where the grooves are finer to produce wood fibre. The defibrator is used in the process of making medium-density_fibreboard.
History
In 1931 the Swedish engineer Arne Asplund filed a patent on a method to defibrate woodchips. As opposed to the Masonite-method, the defibrator-method (also known as the Asplund-method) uses pressurised steam to soften the woodchips, then grinding discs to pull the wood fibres apart. This grinding unit is what Asplund called the defibrator. It became the key product of his company, Defibrator AB. The Defibrator trademark is now held by the Metso Corporation.