Extrusion machines and methods for tubing and sheeting

Claim 1

IN APPARATUS FOR PRODUCING FLATTENED TUBING AND SHEETING, INCLUDING AN EXTRUDER AND DIE FOR EXTRUDING HEATED SYNTHETIC RESINOUS THERMOPLASTIC SEAMLESS TUBING IN NON-SELF-SUSTAINING CONDITION, CONDUITS IN SAID DIE SAID CONDUITS OPENING INTO SUCH TUBING WHEN EXTRUDED TO CIRCULATE A SUPPORTING FLUID THEREIN SAID CONDUITS BEING SPACED FROM THE WALLS OF THE DIE, A TEMPERATURE MODIFYING HOLLOW FORMER SUPPORTED BY SAID DIE WITHIN AND IN CONTACT WITH TUBING WHEN EXTRUDED, CONDUITS PASSING THROUGH THE DIE TO SAID TEMPERATURE MODIFYING FORMER TO CIRCULATE A TEMPERATURE-MODIFYING FLUID IN SAID FORMER, SAID LAST NAMED CONDUITS BEING SPACED FROM WALLS OF THE DIE, A SPREADER ON THE AFTER-BAFFLE SET FORTH HEREINAFTER WHICH SPREADER EXTENDS IN A DIRECTION OPPOSITE TO THAT OF THE DIE TO COLLAPSE EXTRUDED TUBING TO FLATTENED TUBING FOR WIND-UP, AND A WIND-UP ROLL FOR WINDING UP THE FLATTENED TUBING ON THE WIND-UP ROLL WHILE PERMITTING SLIPPAGE, THE IMPROVEMENTS WHICH INCLUDE THE FORMER SURFACE OVER WHICH SUCH TUBING FLOWS IN CHANGING DIRECTION OF FLOW BEING ARCUATE, THE SURFACES OF THE MODIFYING FORMER IN CONTACT WITH TUBING EXTRUDED IN NON-SELF-SUSTAINING CONDITION BEING ROUGHENED TO REDUCE SUBSTANTIALLY ADHESION OF EXTRUDED TUBING TO FORMER, A BAFFLE WITHIN THE FORMER TO REDUCE THE SIZE OF THE TEMPERATURE-MODIFYING CHAMBER WITHIN THE FORMER, AND AN AFTER-BAFFLE SUPPORTED FROM THE FORMER WITHIN EXTRUDED TUBING BEYOND THE FORMER AT A POINT WHERE TUBING EXTRUDED IS IN SELF-SUSTAINING CONDITION, SAID AFTER-BAFFLE BEING OF A SIZE AND CONTOUR EQUAL OF THAT OF TUBING ON THE FORMER TO SEAL SUCH TUBING BEYOND SAID AFTER-BAFFLE.