Continuous polymerization of epsilon-caprolactam

Claim 1

IN A PROCESS FOR CONTINUOUS POLYMERIZATION OF ECAPROLACTAM INITIATED BY WATER UNDER SUPERATMOSPHERIC PRESSURES, THE IMPROVEMENT WHICH COMPRISES HEATING AND THEREBY POLYMERIZING EPSILON-CAPROLACTAM UNDER A WATER VAPOR PRESSURE OF ABOUT 2-10 ATMOSPHERES AT TEMPERATURE BETWEEN ABOUT 240*C. AND ABOUT 280*C. FOR A TIME OF ABOUT 1-5 HOURS THEREBY FORMING A POLY-CAPROAMIDE POLYMERIZATION REACTION MIXTURE, CONTAINING WATER; GIVING SAID POLYMERIZATION REACTION MIXTURE A FORM HAVING HIGH EXPOSED SURFACE AREA OF AT LEAST ABOUT 1 SQUARE INCH PER CUBIC INCH OF VOLUME IN CONTACT WITH AN ATMOSPHERE CAPABLE OF EVAPORATING WATER FROM SAID REACTION MIXTURE, AND MAINTAINING THE REACTION MIXTURE IN SUCH HIGH SURFACE AREA FORM FOR A TIME OF AT LEAST ABOUT 5 SECONDS THEREBY REMOVING WATER THEREFROM; THEREAFTER IN A POLYMERIZATION ZONE TRAVERSED SUBSEQUENTLY TO THE ZDNE CONTAINING THE HIGH SURFACE AREA FORM OF THE REACTION MIXTURE, SUPPLYING THE POLYCAPROAMIDE TO A POOL HAVING EXPOSED SURFACE AREA NOT ABOVE ABOUT 1 SQUARE INCH PER 3 CUBIC INCHES OF VOLUME WHICH POOL IS MAINTAINED IN PLUG FLOW AND WITH AN ATMOSPHERE, OVER SAID POOL, IN WHICH CONTROL IS MAINTAINED ON THE WATER VAPOR PARTIAL PRESSURES AND WITH RESIDENCE TIME IN ALL SUCH POOLS TOTALLING AT LEAST ABOUT 1 HOUR; WHEREBY SUBSEQUENTLY TO THE STAGE OF REMOVING WATER WHILE GIVING THE REACTION MIXTURE A HIGH SURFACE AREA FORM, THE FORMIC ACID RELATIVE VISCOSITY OF THE POLYMER IN THE REACTION MIXTURE INCREASES BY AT LEAST 10%.