Method for blow molding thermoplastic

Claim 1

A METHOD OF FORMING A BOTTLE FOR POLYMER OF A 1-OLEFIN BY BLOW MOLDING WHICH COMPRISES EXTRUDING THE MOLTEN POLYMER IN THE SHAPE OF A PARISON ABOUT AN AXIALLY DISPOSED MANDREL, CLOSING A NECK-FORMING MOLD ABOUT A PORTION OF SAID PARISON PASSING OVER SAID MANDREL THEREBY PRESSING SAID PORTION BETWEEN SAID NECK-FORMING MOLD AND SAID MANDREL, COOLING SAID PORTION TO SET SAME INTO THE SHAPE FORMED BETWEEN SAID MOLD AND MANDREL, ADVANCING SAID NECK MOLD AND PARISON PORTION BEYOND SAID MANDREL, PRESS TOGETHER THE WALLS OF SAID PARISON AT A POINT SPACED FROM SAID NECK MOLD WHILE THE POLYMER AT SAID POINT IS STILL IN A HOT, SEALABLE CONDITION THEREBY FORMING A SEAL BETWEEN ADJACENT PARISON SECTIONS, COOLING THE POLYMER IN THE PARISON SECTION BETWEEN SAID NECK MOLD AND SAID SEAL BELOW THE CRYSTALLINE FREEZING POINT OF SAID POLYMER, REHEATING THE COOLED POLYMER IN SAID SECTION TO WITHIN A FEW DEGREES BELOW THE CRYSTALLINE MELTING POINT OF SAID POLYMER, ENCLOSING THE THUS REHEATED PARISON SECTION WITHIN A BOTTLE MOLD, INTRODUCING THROUGH THE WALL OF SAID PARISON FLUID PRESSURE THEREBY INFLATING SAID SECOND WITH INTERNAL FLUID PRESSURE AGAINST THE WALLS OF SAID BOTTLE MOLD WHILE THE POLYMER IS STILL IN ITS REHEATED CONDITION, COOLING THE POLYMER IN SAID SECTION TO SET THE ORIENRATION PRODUCED ON INFLATION, AND EJECTING THE ORIENTED PLASTIC BOTTLE FROM SAID BOTTLE MOLD.

Claim 2

A METHOD OF FORMING A BOTTLE FOR POLYMER OF A 1-OLEFIN BY BLOW MOLDING WHICH COMPRISES EXTRUDING THE MOLTEN POLYMER IN THE SHAPE OF A PARISON ABOUT AN AXIALLY DISPOSED MANDREL, CLOSING A NECK-FORMING MOLD ABOUT A PORTION OF SAID PARISON PASSING OVER SAID MANDREL THEREBY PRESSING SAID PORTION BETWEEN SAID NECK-FORMING MOLD AND SAID MANDREL, COOLING SAID PORTION TO SET SAME INTO THE SHAPE FORMED BETWEEN SAID MOLD AND MANDREL, ADVANCING SAID NECK MOLD AND PARISON PORTION BEYOND SAID MANDREL, PRESS TOGETHER THE WALLS OF SAID PARISON AT A POINT SPACED FROM SAID NECK MOLD WHILE THE POLYMER AT SAID POINT IS STILL IN A HOT, SEALABLE CONDITION THEREBY FORMING A SEAL BETWEEN ADJACENT PARISON SECTIONS, COOLING THE POLYMER IN THE PARISON SECTION BETWEEN SAID NECK MOLD AND SAID SEAL BELOW THE CRYSTALLINE FREEZING POINT OF SAID POLYMER, REHEATING THE COOLED POLYMER IN SAID SECTION TO WITHIN A FEW DEGREES BELOW THE CRYSTALLINE MELTING POINT OF SAID POLYMER, ENCLOSING THE THUS REHEATED PARISON SECTION WITHIN A BOTTLE MOLD, INTRODUCING THROUGH THE WALL OF SAID PARISON FLUID PRESSURE THEREBY INFLATING SAID SECOND WITH INTERNAL FLUID PRESSURE AGAINST THE WALLS OF SAID BOTTLE MOLD WHILE THE POLYMER IS STILL IN ITS REHEATED CONDITION, COOLING THE POLYMER IN SAID SECTION TO SET THE ORIENRATION PRODUCED ON INFLATION, AND EJECTING THE ORIENTED PLASTIC BOTTLE FROM SAID BOTTLE MOLD.