Method of adjusting choke gap of plastic extruder apparatus

A method of extruding a thermoplastic material employing an extrusion die apparatus having an inner and outer die lip and a first and second end, which forms at said first end a die gap for the extrusion of said material, and forms a generally axial thermoplastic flow passageway from said second to said first end, the flow passageway having a choke gap with a cross sectional area, and which method comprises:

• a) adjusting said choke gap cross sectional area at a plurality of sections about the periphery of said choke gap by slidable, axial movement of a choke ring means within a slot having a selected clearance, said choke ring comprised of castellation elements with holes therein, the choke ring means adapted to move axially between a choke gap non-restrictive position and a choke gap restrictive position;
• and
• b) adjusting said choke ring means by employing a plurality of radially positioned, spaced apart, eccentric, threaded bolts having one end extending into the holes of the castellation elements to adjust axially and to flex said choke ring means in said choke gap by threadable movement of said bolts.

A method of extruding a thermoplastic material employing an extrusion die apparatus having an inner and outer die lip and a first and second end, which forms at said first end a die gap for the extrusion of said material, and forms a generally axial thermoplastic flow passageway from said second to said first end, the flow passageway having a choke gap with a cross sectional area, and which method comprises:

• adjusting said choke gap cross sectional area at a plurality of sections about the periphery of said choke gap, by slidable, axial movement of a choke ring means having a face section and a rear section and a plurality of spaced apart castellation elements at the rear section and axially moving said choke ring means within a slot having a selected clearance and adjacent said choke gap by axially moving said face section of said choke ring means between a choke gap non-restrictive position and a choke gap restrictive position and flexing said face section in said slot by moving said castellation elements.