Polymerization of plurality of aqueous solutions of polyamide-forming reactants witha continuously decreasing pressure

Claim 1

IN A PROCESS FOR THE MANUFACTURE OF SHAPED POLYAMIDE OBJECTS FROM A HIGH MOLECULAR WEIGHT LINEAR POLYAMIDE MADE BY CONDENSATION POLYMERIZING A MONOMER SELECTED FROM THE GROUP CONSISTING OF OMEGA-AMINO ALIPHATIC CARBOXYLIC ACID CONTAINING FROM 6 TO 12 CARBON ATOM AND POLYMETHYLENE DIAMMONIUM SALTS OF ALIPHATIC ALPHA-OMEGA-DICARBOXYLIC ACIDS CONTAINING FROM 8 TO 24 CARBON ATOMS; SAID PROCESS INVOLVING THE STEP OF NITRODUCING AN AQUEOUS SOLUTION OF THE MONOMER INTO THE ENTRY END OF A TUBE WHICH HAS AN INTERNAL DIAMETER WHICH DOES NOT EXCEED 2.5 CM. AND IS HEATED TO THE MONOMER POLYMERIZATION TEMPERATURE, WHEREBY THE MONOMER POLYMERIZES AND EVOLVES AT LEAST 90% OF THE TOTAL THEORETICAL WATER OF CHEMICAL CONDENSATION AS IT PASSES THROUGH THE TUBE, THE PRESSURE BEING AT LEAST 14 ATMOSPHERES AT THE ENTRY END OF SAID TUBE, CONTINUOUSLY DECREASING ALONG THE TUBE AND FALLING AT LEAST TO SUBSTANTIALLY ATMOSPHERIC PRESSURE AT THE EXIT END OF SAID TUBE WHILE ALWAYS PERMITTING THE EVOLUTION OF STEAM AND AT ANY POINT IN THE TUBE HAVING A VALUE CONSTITUTING A CONTINUOUS MONOTONIC SINGLE-VALUE FUNCTION OF THE DISTANCE OF SAID POINT ALONG THE TUBE, INTRODUCING THE POLYAMIDE PASSING OUT OF THE TUBE INTO A RESERVOIR VESSEL, HEATING THE POLYAMIDE IN THE VESSEL AND MELT-SPINNING THE POLYAMIDE INTO SHAPED OBJECTS, THE IMPROVEMENT COMPRISING UTILIZING, AS THE AQUEOUS SOLUTION OF THE MONOMER INTRODUCED INTO THE TUBE, A PLURALITY OF AQUEOUS SOLUTIONS OF THE MONOMER, WHEREIN THE SOLUTIONS DIFFER IN CONCENTRATION BY 5 TO 50% BY WEIGHT, CALCULATED ON THE SOLUTION, AND EACH OF THE SOLUTIONS HAS A CONCENTRATION OF FROM 0 TO ABOUT 70% BY WEIGHT OF MONOMER, AND WHEREIN THE TOTAL VOLUME OF SOLUTION FED TO THE TUBE IS ABOUT CONSTANT BUT THE RATE OF PRODUCTION OF POLYAMIDE IS VARIED BY VARYING THE PROPORTIONS IN WHICH THE MONOMER SOLUTIONS ARE INTRODUCED WHILE CONTINUOUSLY SUPPLYING MONOMER, WHEREBY THE MOLTEN POLYAMIDE LEVEL IN THE RESERVOIR VESSEL IS KEPT SUBSTANTIALLY CONSTANT.