Heated die-plate for underwater die-face cutter for plastics - has thermal insulating channels filled with inert gas between die holes and between die-face and heating channels

摘要

Die plate for underwater dieface cutter for plastics granulates with channels for heating fluid between the die holes, in which between these and the cutting face, a further set of closed insulating channels is provided, filled with air or inert gas. - The isolating channels pref. run between each row of die holes and parallel to the die face. The isolating channels may have an oval cross-section, with the major axis in the plane of the die plate, with minimum wall thickness to the die holes for maximum axial insulation consistent with mechanical integrity. The diagrams show a rectilinear arrangement of die holes, which are axially stepped down in direction, in an overall annular area, with L-shaped heating channels orthogonally between them. These are connected to an outer circumferential channel, which may carry oil or steam. The isolating channels (which must follow similar paths) are preferably formed by spark erosion and are blocked at their outer ends.