Plastic Stress Test Protocols
Polycarbonate stress cracking
| Polysulfone | Stress Level (PSI) |
| 1) Cellosolve (2-Ethoxyethanol) | >1200 |
| 2) 1,1,1 Trichloroethane | 600 |
| 3) Ethyl Acetate | 200 |
Completely immerse or dab component in critical area for one minute. Observe for cracking.
Steps to test for a specific range; Start with the least aggressive chemical (#1) and proceed through each until cracking occurs.
| Polycarbonate Stress Level (PSI) | Stress Level (PSI) |
| 1) 10% Ethyl Acetate in Methanol | >2500 |
| 2) 20% Ethyl Acetate in Methanol | 1800 |
| 3) 30% Ethyl Acetate in Methanol | 1100 |
| 4) 40% Ethyl Acetate in Methanol | 700 |
| 5) 50% Ethyl Acetate in Methanol | 600 |
Immerse part in bath for 3 minutes. Dry and check for cracks within 1 minute. When no cracks are visible the appropriate stress level has not been reached.
| Ultem® | Stress Level (PSI) |
| Chemical: | 1,1,2-Trichloroethane @ Room Temperature |
| Time to craze Stress Level (PSI) | Stress Level (PSI) |
| ¼ minute | 1200 |
| ½ minute | 1000 |
| 1 minute | 800 |
| 3 minutes | 650 |
| 5 minutes | 600 |