Patent ID: 6210030
Filing Date: 2001-04-03
Classification: B01F,B29B,B29C,B29K

Abstract:
An apparatus for continuously reducing the viscosity of molten moldable polymeric material by shear vibration under extensional flow to cause disentanglement, said apparatus comprising:(a) at least one station treatment cavity defined by a gap composed of two closely separated surfaces in relative motion with each other at given speed and/or submitted to relative oscillations, with given frequency and amplitude, as to produce a shear deformation on a molten moldable material and a controlled variation of the gap dimension; at least one of said surfaces having on its contour a profile of rib means over which the molten moldable material moves, said treatment cavity comprising an inlet through which the molten moldable material can pass into and an outlet through which it can exit the treatment cavity; said treatment cavity geometry allowing the shear strain and the shear strain rate imposed on the passing molten moldable material to vary controllably;(b) at least one feeder for preparing a molten moldable material; said feeder including a means for expelling the molten moldable material through its outlet into the station treatment cavity;(c) at least one accumulator for collecting the treated molten moldable material before it is sent to either a pelletizer system or to a pumping station;(d) means for exerting a shear vibration of given frequency and amplitude coupled with fatigue extensional flow on the molten moldable material contained within the treatment cavity;(e) means for varying the amplitude of the shear vibration applied on the molten moldable material;(f) means for exerting a shear drag at given strain rate of the molten moldable material as it flows through from the inlet to the outlet of the treatment cavity;(g) said rib means exerting a variation of the shear strain rate of the molten moldable material as it flows through from the inlet to the outlet of the treatment cavity such that it produces extensional acceleration/deceleration of the flow;(h) means for continuously moving the molten moldable material located in the station treatment cavity from the inlet toward the outlet;(i) means for monitoring and controlling the temperature of the molten moldable material contained within the at least one feeder and the treatment cavity;(j) means for monitoring and controlling the pressure of the molten moldable material contained within the at least one feeder; and(k) a means for monitoring and controlling the torque exerted on the molten moldable material contained within the treatment cavity.