Process for the elimination of the unconverted polymer-forming monomers from synthetic linear polyamides

Claim 1

A PROCESS FOR THE SEPARATION OF UNCONVERTED MONOMER FROM A HIGHLY VISCOUS MELT OF A POLYAMIDE CONTAINING THE SAME, SAID POLYAMIDE BEING FORMED FROM A MATERIAL SELECTED FROM THE CLASS CONSISTING OF 6-AMINOHEXANOIC ACID, CAPROLACTAM AND A MIXTURE OF A CONDENSATION PRODUCT OF ADIPIC ACID AND HEXAMETHYLENE DIAMINE WITH CAPROLACTAM, WHICH COMPRISES FORMING A HIGHLY VISCOUS MELT OF SAID POLYAMIDE COMPRISING SUBSTANTIALLY COMPLETELY POLYMERIZED MONOMER AND UNCONVERTED MONOMER, INTRODUCING A STRONG CURRENT OF SUPERHEATED STEAM MAINTAINED AT A TEMPERATURE OF BETWEEN 200*-300* C. INTO SAID MELT WHEREBY SAID STEAM IS CAUSED TO ENTER SAID MELT AND PASS THROUGH IT, SWEEPING WITH IT UNCONVERTED MONOMER, SEPARATING THE STEAM AND UNCONVERTED MONOMER CONTAINED THEREIN FROM THE MELT, CONVEYING SAID MELT SUBSTANTIALLY FREE OF MONOMER TO A DEGASSING ZONE AND ALLOWING SAID MELT TO QUIESCE IN SAID DEGASSING ZONE UNTIL MOST OF THE RESIDUAL STEAM BUBBLES ARE FREED FROM SAID MELT, SAID MELT REMAINING IN SAID DEGASSING ZONE AT MOST FOR ABOUT 30 MINUTES.