Case Study 2 - Dishwasher Stress Crack Resistance

The researchers wore out before Eastman Tritan™ copolyester did.​
Representative molded housewares parts were tested to assess dishwasher stress crack resistance. Handled drinking mugs with thick bases to give a luxurious, glasslike appearance were selected for testing.

Parts were molded from Eastman Tritan™ copolyester and a 12 melt flow PC resin, using midpoint conditions from manufacturer's recommendations. All mugs were washed in a residential dishwasher using a leading powdered detergent.

The images below show the effect of residential dishwashing cycles on molded parts: after 8 cycles, the polycarbonate mug was badly cracked; after 15 cycles, the base was breaking and almost completely separated from the polycarbonate mug. Meanwhile, whether it's 50 cycles or even 500 cycles, a mug molded of Eastman Tritan™ copolyester retains its clarity and integrity.

Polycarbonate - 8 cycles (cracking)

Polycarbonate - 15 cycles (breakage)

Tritan copolyester - 50 cycles (clear)