Method for the extrusion of plastics

Claim 1

A METHOD FOR EXTRUDING PLASTIC MATERIAL WHICH COMPRISES: (A) PROVIDING AN EXTRUDER HAVING A DIE PLATE DEFINING AN ORIFICE, A RESERVOIR FOR A PLASTIC FEED STOCK MATERIAL AND A RECIPROCATING PISTON-TYPE PULSATOR POSITIONED IN SAID RESERVOIR, THE PISTON OF SAID PULSATOR HAVING A FLAT FACE AND BEING PARALLEL TO THE DIE PLATE OF SAID EXTRUDER AND CENTERED WITH RESPECT TO THE CENTER AXIS OF THE ORIFICE IN SAID DIE PLATE OF SAID EXTRUDER, SAID PISTON BEING MAINTAINED AT CLOSE POSITION SUCH THAT THE DISTANCE BETWEEN THE FACE OF SAID PISTON AND SAID DIE PLATE IS OF THE SAME ORDER OF MAGNITUDE AS THE AMPLITUDE OF SAID PULSATING PISTON, (B) INTRODUCING INTO SAID RESERVOIR A FEEDSTOCK SUPPLY OF A LIQUID, FLOWABLE, VISCOUS PLASTIC, (C) MAINTANING SAID PLASTIC FEED STOCK SUPPLY IN SAID RESERVOIR AS A VISCOUS LIQUID AT SUBSTANTIALLY ATMOSPHERIC PRESSURE, SAID LIQUID PLASTIC FEED STOCK ALSO BEING IN CONTACT WITH THE DIE PLATE OF SAID EXTRUDER, (D) ACCELERATING THE FACE OF SAID PISTON THROUGH THE BODY OF SAID VISCOUS, LIQUID MATERIAL IN THE RESERVOIR OF SAID EXTRUDER THEREBY SUBJECTING ONLY THAT VOLUME OF SAID LIQUID PLASTIC MATERIAL DIRECTLY BETWEEN THE FLAT FACE OF SAID PISTON AND SAID DIE PLATE TO RAPID, RECIPROCATING LINEAR PRESSURE PULSES OF AT LEAST 1 PULSE PER SECOND AND OF AMPLITUDE OF FROM ABOUT 0.005 TO ABOUT 0.100 INCH FROM SAID PULSATING PISTON THEREBY INDUCING CORRESPONDING LARGE MOMENTARY HIGH PRESSURE FORCES IN SAID VOLUME OF SAID LIQUID PLASTIC DIRECTLY BETWEEN THE FLAT FACE OF SAID PISTON AND SAID DIE PLATE WHILE MAINTAINING THE REMAINDER OF SAID LIQUID FEED STOCK SUPPLY IN SAID RESERVOIR AT SUBSTANTIALLY ATMOSPHERIC PRESSURE, SAID HIGH PRESSURE FORCE IN SAID LIQUID BALANCING THE FORCE REQUIRED TO ACCELERATE THE FACE OF THE PISTON AGAINST THE RESISTANCE OF SAID VISCOUS LIQUID PLASTIC, SAID FORCE BEING SUFFICIENT TO PROVIDE FLOW IN SAID VISCOUS LIQUID PLASTIC, (E) BEARING SAID FORCE REQUIRED TO PRODUCE SAID VISCOUS FLOW IN SAID VOLUME OF LIQUID DIRECTLY BETWEEN THE FLAT FACE OF SAID PISTON AND SAID DIE PLATE BY A PORTION OF DIE PLATE DIRECTLY IN LINE WITH THE ACCELERATING PISTON FACE THEREBY INDUCING VISCOUS FLOW IN SAID VOLUME OF SAID LIQUID PLASTIC FEED STOCK SUBJECTED TO SAID INDUCED HIGH PRESSURE FORCESM (F) FLOWING SAID VOLUME OF VISCOUS LIQUID DIRECTLY BETWEEN THE FLAT FACE OF SAID PISTON AND SAID DIE PLATE SUBSTANTIALLY UNIDIRECTIONALLY TOWARD THE ORIFICE OF SAID DIE PLATE, (G9) FORCING SAID LIQUID PLASTIC FEED STOCK THROUGH SAID DIE ORIFICE IN A SUBSTANTIALLY CONTINUOUS MANNER BY ACTION OF SAID INDUCED HIGH PRESSURE FORCES ON SAID VOLUME OF LIQUID SUBJECTED TO SAID PRESSURE PULSES, AND (H) RECOVERING A FORMED EXTRUDED PRODUCT.

Claim 2

A METHOD FOR EXTRUDING PLASTIC MATERIAL WHICH COMPRISES: (A) PROVIDING AN EXTRUDER HAVING A DIE PLATE DEFINING AN ORIFICE, A RESERVOIR FOR A PLASTIC FEED STOCK MATERIAL AND A RECIPROCATING PISTON-TYPE PULSATOR POSITIONED IN SAID RESERVOIR, THE PISTON OF SAID PULSATOR HAVING A FLAT FACE AND BEING PARALLEL TO THE DIE PLATE OF SAID EXTRUDER AND CENTERED WITH RESPECT TO THE CENTER AXIS OF THE ORIFICE IN SAID DIE PLATE OF SAID EXTRUDER, SAID PISTON BEING MAINTAINED AT CLOSE POSITION SUCH THAT THE DISTANCE BETWEEN THE FACE OF SAID PISTON AND SAID DIE PLATE IS OF THE SAME ORDER OF MAGNITUDE AS THE AMPLITUDE OF SAID PULSATING PISTON, (B) INTRODUCING INTO SAID RESERVOIR A FEEDSTOCK SUPPLY OF A LIQUID, FLOWABLE, VISCOUS PLASTIC, (C) MAINTANING SAID PLASTIC FEED STOCK SUPPLY IN SAID RESERVOIR AS A VISCOUS LIQUID AT SUBSTANTIALLY ATMOSPHERIC PRESSURE, SAID LIQUID PLASTIC FEED STOCK ALSO BEING IN CONTACT WITH THE DIE PLATE OF SAID EXTRUDER, (D) ACCELERATING THE FACE OF SAID PISTON THROUGH THE BODY OF SAID VISCOUS, LIQUID MATERIAL IN THE RESERVOIR OF SAID EXTRUDER THEREBY SUBJECTING ONLY THAT VOLUME OF SAID LIQUID PLASTIC MATERIAL DIRECTLY BETWEEN THE FLAT FACE OF SAID PISTON AND SAID DIE PLATE TO RAPID, RECIPROCATING LINEAR PRESSURE PULSES OF AT LEAST 1 PULSE PER SECOND AND OF AMPLITUDE OF FROM ABOUT 0.005 TO ABOUT 0.100 INCH FROM SAID PULSATING PISTON THEREBY INDUCING CORRESPONDING LARGE MOMENTARY HIGH PRESSURE FORCES IN SAID VOLUME OF SAID LIQUID PLASTIC DIRECTLY BETWEEN THE FLAT FACE OF SAID PISTON AND SAID DIE PLATE WHILE MAINTAINING THE REMAINDER OF SAID LIQUID FEED STOCK SUPPLY IN SAID RESERVOIR AT SUBSTANTIALLY ATMOSPHERIC PRESSURE, SAID HIGH PRESSURE FORCE IN SAID LIQUID BALANCING THE FORCE REQUIRED TO ACCELERATE THE FACE OF THE PISTON AGAINST THE RESISTANCE OF SAID VISCOUS LIQUID PLASTIC, SAID FORCE BEING SUFFICIENT TO PROVIDE FLOW IN SAID VISCOUS LIQUID PLASTIC, (E) BEARING SAID FORCE REQUIRED TO PRODUCE SAID VISCOUS FLOW IN SAID VOLUME OF LIQUID DIRECTLY BETWEEN THE FLAT FACE OF SAID PISTON AND SAID DIE PLATE BY A PORTION OF DIE PLATE DIRECTLY IN LINE WITH THE ACCELERATING PISTON FACE THEREBY INDUCING VISCOUS FLOW IN SAID VOLUME OF SAID LIQUID PLASTIC FEED STOCK SUBJECTED TO SAID INDUCED HIGH PRESSURE FORCESM (F) FLOWING SAID VOLUME OF VISCOUS LIQUID DIRECTLY BETWEEN THE FLAT FACE OF SAID PISTON AND SAID DIE PLATE SUBSTANTIALLY UNIDIRECTIONALLY TOWARD THE ORIFICE OF SAID DIE PLATE, (G9) FORCING SAID LIQUID PLASTIC FEED STOCK THROUGH SAID DIE ORIFICE IN A SUBSTANTIALLY CONTINUOUS MANNER BY ACTION OF SAID INDUCED HIGH PRESSURE FORCES ON SAID VOLUME OF LIQUID SUBJECTED TO SAID PRESSURE PULSES, AND (H) RECOVERING A FORMED EXTRUDED PRODUCT.