Method for expanding polymer bit-pieces

Claim 1

A METHOD OF EXPANDING BIT-PIECE OF AN EXPANDABLE THERMOPLASTIC ORGANIC POLYMER IMPREGNATED WITH AN EXPANSION AGENT, WHICH METHOD COMPRISES A. PROVIDING AN ELONGATED TANK HAVING A FEED INPUT END AND A PRODUCT DISCHARGE END AND SUBSTANTIALLY FREE OF SPECIFIC MEANS TO DISINTEGRATE AGGLOMERATES OF EXPANDING AND/OR EXPANDED BIT-PIECE; B. MAINTAINING SAID TANK PARTIALLY FILLED WITH AN AQUEOUS BATH; C. MAINTAINING SAID BATH UNDER ATMOSPHERIC PRESSURE AND AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 160* TO ABOUT 212*F. OR SLIGHTLY HIGHER, SAID TEMPERATURE BEING SUFFICIENT TO CAUSE THE EXPANSION AGENT IN SAID BIT-PIECES TO EXPAND THEREIN AND THEREBY EXPAND SAID BIT-PIECES; D. FEEDING SAID BIT-PIECE THROUGH SAID FEED INPUT END OF SAID TANK INTO SAID BATH AT A FLOW RATE WITHIN THE RANGE OF FROM ABOUT 2.6 TO ABOUT 21LB/HR/CU.FT. OF SAID TANK SO THAT SAID BIT-PIECE ARE IMMERSED IN AND HEATED BY SAID BATH TO CAUSE EXPANSION OF SAID BIT-PIECE AND REDUCTION OF THE BULK DENSITY THEREOF TO LESS THAN THAT OF SAID BATH; E. ALLOWING SAID SO-EXPANDING BIT-PIECE HAVING A BULK DENSITY LESS THAN THAT OF SAID AQUEOUS BATH TO FLOAT ALONG THE SURFACE OF SAID BATH, AND AT THE SAME TIME PROPELLING THE SO-EXPANDING BIT-PIECE TOWARD THE DISCHARGE END OF SAID TANK AT SUCH A RATE THAT SAID EXPANDING BIT-PIECE ARE HEATED BY SAID BATH FOR A TIME SUFFICIENT FOR THEM TO ATTAIN THE SELECTED EXTEND OF EXPANSION WHEN THEY ARE AT THE DISCHARGE END OF SAID TANK, WHEREBY SAID BIT-PIECE FLOAT FREELY WITHOUT INCLUSION OF SPECIFIC MEANS TO DISINTEGRATE AGGLOMERATES AND REMAIN DISCRETE AND SUBSTANTIALLY FREE OF AGGLOMERATES THEREOF AS THEY REACH SAID DISCHARGE END; AND F. DISCHARGING THE THUS EXPANDED BIT-PIECE SUBSTANTIALLY FREE OF AGGLOMERATES THEREOF FROM SAID DISCHARGE END.

Claim 2

A METHOD OF EXPANDING BIT-PIECE OF AN EXPANDABLE THERMOPLASTIC ORGANIC POLYMER IMPREGNATED WITH AN EXPANSION AGENT, WHICH METHOD COMPRISES A. PROVIDING AN ELONGATED TANK HAVING A FEED INPUT END AND A PRODUCT DISCHARGE END AND SUBSTANTIALLY FREE OF SPECIFIC MEANS TO DISINTEGRATE AGGLOMERATES OF EXPANDING AND/OR EXPANDED BIT-PIECE; B. MAINTAINING SAID TANK PARTIALLY FILLED WITH AN AQUEOUS BATH; C. MAINTAINING SAID BATH UNDER ATMOSPHERIC PRESSURE AND AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 160* TO ABOUT 212*F. OR SLIGHTLY HIGHER, SAID TEMPERATURE BEING SUFFICIENT TO CAUSE THE EXPANSION AGENT IN SAID BIT-PIECES TO EXPAND THEREIN AND THEREBY EXPAND SAID BIT-PIECES; D. FEEDING SAID BIT-PIECE THROUGH SAID FEED INPUT END OF SAID TANK INTO SAID BATH AT A FLOW RATE WITHIN THE RANGE OF FROM ABOUT 2.6 TO ABOUT 21LB/HR/CU.FT. OF SAID TANK SO THAT SAID BIT-PIECE ARE IMMERSED IN AND HEATED BY SAID BATH TO CAUSE EXPANSION OF SAID BIT-PIECE AND REDUCTION OF THE BULK DENSITY THEREOF TO LESS THAN THAT OF SAID BATH; E. ALLOWING SAID SO-EXPANDING BIT-PIECE HAVING A BULK DENSITY LESS THAN THAT OF SAID AQUEOUS BATH TO FLOAT ALONG THE SURFACE OF SAID BATH, AND AT THE SAME TIME PROPELLING THE SO-EXPANDING BIT-PIECE TOWARD THE DISCHARGE END OF SAID TANK AT SUCH A RATE THAT SAID EXPANDING BIT-PIECE ARE HEATED BY SAID BATH FOR A TIME SUFFICIENT FOR THEM TO ATTAIN THE SELECTED EXTEND OF EXPANSION WHEN THEY ARE AT THE DISCHARGE END OF SAID TANK, WHEREBY SAID BIT-PIECE FLOAT FREELY WITHOUT INCLUSION OF SPECIFIC MEANS TO DISINTEGRATE AGGLOMERATES AND REMAIN DISCRETE AND SUBSTANTIALLY FREE OF AGGLOMERATES THEREOF AS THEY REACH SAID DISCHARGE END; AND F. DISCHARGING THE THUS EXPANDED BIT-PIECE SUBSTANTIALLY FREE OF AGGLOMERATES THEREOF FROM SAID DISCHARGE END.