Underwater pelletizers (UWP) in PA6 production

For many decades, polyamide 6 has been produced using continuous polymerization lines. The early design of pelletizing systems with a cooling bath and dry cut are sometimes still used even today.  Later, systems with automatic strand guidance and wet cut became the accepted pelltizing method. Now, for more than 10 years, underwater pelletizing systems have been used in PA6 polymeriziation lines. A detailed system comparison between underwater pelletizers (UWP) and the different types of strand pelletizers, serves to illustrate developing trends.