Method for the continuous extrusion of multiple small cross-section thermoplastic polymeric resinous foam profiles

Claim 1

A METHOD OF PREPARING MULTIPLE CONTINUOUS EXTRUDATES HAVING PREDETERMINED CROSS SECTION PROFILES, FROM THERMOPLASTIC POLYMERIC RESINOUS MATERIAL CONTAINING A BOWING AGENT, COMPRISING: A. FORCING SAID MATERIAL IN A MOLTEN CONDITION THROUGH A DIE HAVING A MULTIPLICITY OF ORIFICES INTO AN UNCONFIND ZONE OF LOWER PRESSURE, THEREBY PROVIDING A MULTIPLICITY OF EXTRUDATES IN A SOFTENED BUT UNEXPANDED CONDITION SO THAT PARTIAL EXPANSION OF EACH EXTRUDATE OCCURS IN THE UNCONFINED ZONE, B. PASSING EACH OF THE PARTIALLY EXPANDED EXTRUDATES THROUGH A CONFINED PASSAGE OF PREDETERMINED CONFIGURATION AND FORMED FROM COOLING WALL SURFACES MOVING WITH SAID EXTRUDATE TO SHAPE SAID EXTRUDATE INTO A PREDETEMINED CROSS SECTION PROFILE AND TO COOL THE SURFACE LAYERS OF SAID

Claim 2

A METHOD OF PREPARING MULTIPLE CONTINUOUS EXTRUDATES HAVING PREDETERMINED CROSS SECTION PROFILES, FROM THERMOPLASTIC POLYMERIC RESINOUS MATERIAL CONTAINING A BOWING AGENT, COMPRISING: A. FORCING SAID MATERIAL IN A MOLTEN CONDITION THROUGH A DIE HAVING A MULTIPLICITY OF ORIFICES INTO AN UNCONFIND ZONE OF LOWER PRESSURE, THEREBY PROVIDING A MULTIPLICITY OF EXTRUDATES IN A SOFTENED BUT UNEXPANDED CONDITION SO THAT PARTIAL EXPANSION OF EACH EXTRUDATE OCCURS IN THE UNCONFINED ZONE, B. PASSING EACH OF THE PARTIALLY EXPANDED EXTRUDATES THROUGH A CONFINED PASSAGE OF PREDETERMINED CONFIGURATION AND FORMED FROM COOLING WALL SURFACES MOVING WITH SAID EXTRUDATE TO SHAPE SAID EXTRUDATE INTO A PREDETEMINED CROSS SECTION PROFILE AND TO COOL THE SURFACE LAYERS OF SAID

Claim 3

A method of preparing multiple continuous extrudates having predetermined cross-section profiles, from thermoplastic polymeric resinous material containing a blowing agent, comprising: a. extruding said material in a molten condition through a die having a multiplicity of orifices into an unconfined zone of lower pressure to provide a multiplicity of extrudates in a softened but unexpanded condition; b. allowing each of said extrudates to partially expand in said unconfined zone; c. passing each of the partially expanded extrudates through a confined passage of predetermined configuration while cooling the surface layers of the extrudate to substantially solidify the surface layers of the material; said confined passage moving with said extrudate; d. bending the extrudates in an arc in one direction while further cooling one side of the extrudates; and e. bending the extrudates in a reverse arc while cooling the opposite side of extrudates.

Claim 4

A method of preparing multiple continuous extrudates having predetermined cross-section profiles, from thermoplastic polymeric resinous material containing a blowing agent, comprising: a. extruding said material in a molten condition through a die having a multiplicity of orifices into an unconfined zone of lower pressure to provide a multiplicity of extrudates in a softened but unexpanded condition; b. allowing each of said extrudates to partially expand in said unconfined zone; c. passing each of the partially expanded extrudates through a confined passage of predetermined configuration while cooling the surface layers of the extrudate to substantially solidify the surface layers of the material; said confined passage moving with said extrudate; d. bending the extrudates in an arc in one direction while further cooling one side of the extrudates; and e. bending the extrudates in a reverse arc while cooling the opposite side of extrudates.