Patent ID: 6216880
Filing Date: 2001-04-17
Classification: B01D,B29C

Abstract:
A continuous filter device for separating a particulate material from a stream of a flowable plastic material to be filtered , having the particulate material entrained therein, the filter device comprising:a body member having inlet and outlet ports, and a flow path for the plastic material which extends between said inlet and outlet ports;a filter assembly extending transverse to the flow path creating a first channel portion upstream of the filter assembly, and a second channel portion downstream of the filter assembly, said filter assembly comprising a continuous filter band slidably movable with respect to a perforated back plate;a clamping means for sealingly clamping peripheral edges of a filtering area of the filter band against the back plate, said clamping means comprising a reciprocal valve member, said valve member comprising a piston member located in the second channel portion downstream of the filter band with a front face arranged parallel to the filter band, said piston member having a portion of the flow path extending thereinto and from a first end on a side of the valve member towards a second end at the front face of the piston member; anddrive means to reciprocate the piston member between an advanced position in which the peripheral edges of the filtering area of the filter band are clamped to seal against the back-plate, and in which the portion of the flow path in the piston member is connected to a port, and a retracted position in which the portion of the flow path in the piston member is disconnected from the port, and which retracted position disengages the filter band from the back-plate to allow sliding of the filter band.