A dynamically vulcanized alloy containing an elastomer and a thermoplastic resin is prepared by a process wherein supercritical fluid is injected into the thermoplastic elastomeric material as the material is mixed in an extruder. The material is mixed under conditions such that the thermoplastic elastomeric material is dynamically vulcanized wherein the elastomer forms a discontinuous dispersed of small particles in a continuous phase of the thermoplastic resin. The DVA material may then be directly formed into film or sheets by the use of at least one set of rolls located adjacent to the extruder outlet.