Process for removing the solvent from an elastomeric polymer solution

A process for removing the solvent from an elastomeric polymer solution which contains at least 8% by weight of elastomeric polymer, said elastomeric polymer solution undergoing a preprocessing step in order to remove a large part of said solvent, thereafter said elastomeric polymer solution being fed into a main extruder which has a screw mechanism provided therein so that said elastomeric polymer solution is moved forward in said main extruder in order to remove remaining said solvent via at least one vapor removal vent of said main extruder, the improvement comprising that said preprocessing step includes the steps of:

• (a) introducing a heating fluid and said elastomeric polymer solution into a static mixer in order to mix completely said heating fluid and said elastomeric polymer solution and heat rapidly and homogeneously said elastomeric polymer solution to a temperature of between 60.degree. C. and 250.degree. C.;
• (b) spraying the mixture of said heating fluid and said elastomeric polymer solution under a depressurization atmosphere in order to vaporize said heating fluid and said solvent out of said mixture and form a vaporized heating fluid, a vaporized solvent and a powdered elastomeric polymer;
• (c) introducing said vaporized heating fluid, said vaporized solvent and said powdered elastomeric polymer into a fluid-solid separation chamber which has a pair of intermeshing twin extruding screws mounted therein;
• and
• (d) extruding said powdered elastomeric polymer into said main extruder via a polymer outlet of said fluid-solid separation chamber by means of said intermeshing twin extruding screws while removing said vaporized heating fluid and said vaporized solvent via a vapor outlet of said fluid-solid separation chamber.