Tritan Copolyester Material from Eastman

Apparently barrel size was the issue - shot size was too small and material is degrading in the barrel. Tritan is sensitive to that as are most polymers but maybe more so.

Eastman Tritan(tm) Copolyester is a very tough material, with similar impact properties to PC. With any polyester (or polycarbonate for that matter) material, drying is important. You must use a properly sized dessicant dryer in good working order (dew point of minimum -30 °C, providing at least 3.5-4 cubic meters per hour of air per kg of material processed). Polymer should be dried at 88 °C for a minimum of 4 hours to provide a moisture level of 0.03% or lower. As with any material, melt temperatures should be measured to ensure the material doesn't degrade - avoid melt temperatures above 290°C for any extended period, and keep shot size at least 40% of machine capacity (and more preferably above 60%) to minimize residence time. Mold temperatures of 60-70°C will help minimize residual stress, though this is less of a problem with Tritan than with polycarbonate. Gate sizes should be similar to PC, and it sounds like your parts are filling adequately. Finally, following design guidelines for Tritan(tm) is helpful in ensuring that tough, impact resistant parts are produced. Eastman Chemical can provide expert design and processing assistance if necessary to assure design and processing guidelines are followed.

Are you dry enough?

brent