Method for making blown rubber

Claim 1

A METHOD OF CONTINUOUSLY PRODUCING BLOWN RUBBER PRODUCTS COVERED AT LEAST IN PART BY A THIN SHEET OF NONBLWON RUBBER COMPRISING IN COMBINATION THE STEPS OF PREPARING TWO RUBBER STOCKS, A FIRST OF SAID RUBBER STOCKS CONTAINING A CHEMICAL BLOWING AGENT CAPABLE OF DECOMPOSING TO LIBERATE GAS AT ELEVATED TEMPERATURES AND CONTAINING AN ACCELERATOR, SAID STOCKS BEING SO COMPOUNDED AND SAID TEMPERATURES BEING SO SELECTED THAT BLOWING OF SAID FIRST STOCK OCCURS AND THEREAFTER VULCANIZATION OF SAID STOCKS OCCURS WHILE SAID STOCKS ARE AT SAID ELEVATED TEMPERATURE, CONTINUOUSLY EXTRUDING SAID FIRST STOCK CONTAINING SAID BLOWING AGENT THROUGH A DIE AND CONTINOUSLY AND CONCURRENTLY EXTRUDING THE OTHER STOCK OVER AT LEAST PART OF THE PERIPHERY OF SAID FIRST STOK AND THEN CONTINUOUSLY SUBJECTING BOTH STOCK WHILE CONFINED IN AN ELONGATED TUBE HAVING THE FINAL CROSS-SECTIONAL SHAPE OF THE PRODUCT TO HEAT TO CAUSE BLOWING OF SAID FIRST STOCK IN A LINEAR DIRECTION AND THEREAFTER TO CAUSE VULCANIZATION OF BOTH STOCKS WHILE CONTINOUSLY MAINTAINING A UNIFLRM ARATE OF EMERGENCE OF SAID STOCKS FROM SAID ENLONGATED TUBE IN ORDER TO STABILIZE THE DEGREE OF BLOWING OF THE FIRST STOCK AND TO MAINTAIN THE STOCKS UNDER A DEFINITE PRESSURE DURING BLOQING AND VULCANIZATION.

Claim 2

A METHOD OF CONTINUOUSLY PRODUCING BLOWN RUBBER PRODUCTS COVERED AT LEAST IN PART BY A THIN SHEET OF NONBLWON RUBBER COMPRISING IN COMBINATION THE STEPS OF PREPARING TWO RUBBER STOCKS, A FIRST OF SAID RUBBER STOCKS CONTAINING A CHEMICAL BLOWING AGENT CAPABLE OF DECOMPOSING TO LIBERATE GAS AT ELEVATED TEMPERATURES AND CONTAINING AN ACCELERATOR, SAID STOCKS BEING SO COMPOUNDED AND SAID TEMPERATURES BEING SO SELECTED THAT BLOWING OF SAID FIRST STOCK OCCURS AND THEREAFTER VULCANIZATION OF SAID STOCKS OCCURS WHILE SAID STOCKS ARE AT SAID ELEVATED TEMPERATURE, CONTINUOUSLY EXTRUDING SAID FIRST STOCK CONTAINING SAID BLOWING AGENT THROUGH A DIE AND CONTINOUSLY AND CONCURRENTLY EXTRUDING THE OTHER STOCK OVER AT LEAST PART OF THE PERIPHERY OF SAID FIRST STOK AND THEN CONTINUOUSLY SUBJECTING BOTH STOCK WHILE CONFINED IN AN ELONGATED TUBE HAVING THE FINAL CROSS-SECTIONAL SHAPE OF THE PRODUCT TO HEAT TO CAUSE BLOWING OF SAID FIRST STOCK IN A LINEAR DIRECTION AND THEREAFTER TO CAUSE VULCANIZATION OF BOTH STOCKS WHILE CONTINOUSLY MAINTAINING A UNIFLRM ARATE OF EMERGENCE OF SAID STOCKS FROM SAID ENLONGATED TUBE IN ORDER TO STABILIZE THE DEGREE OF BLOWING OF THE FIRST STOCK AND TO MAINTAIN THE STOCKS UNDER A DEFINITE PRESSURE DURING BLOQING AND VULCANIZATION.