DEVICE FOR underwater pelletizing THERMOPLASTIC PLASTIC STRANDS

摘要

The invention relates to an apparatus for underwater pelletizing of thermoplastic plastic strands with a flanged to the pelletizer end wall (10) of the pelletizer, with an axially slidably mounted shaft bearing (5), with a shaft bearing (5) and the end wall (10) penetrating a cutter head (2) carrying the blade shaft (1), which (4) is set into rotary motion by a shaft drive motor, and with a control unit for a pneumatic cylinder (9) for axial loading of the blade head (2) in dependence on a predetermined desired value for the contact pressure of the granulating (3) to a perforated plate. To achieve advantageous Anpressbedingungen for granulating is proposed that the shaft bearing (5) by a rack (7) is axially moved forward or backward by a pinion (8) engages in the rack (7) for transmitting a reset pulse, of the pneumatic cylinder (9) is transmitted to the pinion (8), and in that the pneumatic cylinder (9) via a proportional pneumatic valve (12) is controlled closed loop of the control unit.