Probing Critical Factors Behind Blister Formation and Adhesion Loss in Standard Atlas Cell Testing

Abstract Long-term performance of urethane-lined spools in oil sands service is often compromised by blister formation and liner delamination. These failures carry significant business implications, as liner loss can result in extended production downtime. This study investigates the critical failure mechanisms by subjecting a polyurethane (PU) liner to six modified Atlas Cell conditions over a 15-week period. The objective was to evaluate a cold-wall hypothesis, which attributes failure to temperature-dependent moisture solubility and precipitation at the urethane and steel interface during thermal cycling. All tests maintained an internal temperature of 50 °C, while external temperatures varied from constant (30 °C, - 30 °C) to cyclic (30 °C/-30 °C with intermediate steps of 0, 10, and 20 °C). Comparative results revealed that blistering correlated with high thermal gradients and was exacerbated by liner defects. Film thickness and weight increased across all tests, with greater changes under more severe thermal gradients. Adhesion loss varied with exposure conditions; high external temperatures and alternating cycles caused the most degradation. Notably, contrary to conventional expectations, the test with the highest thermal gradient exhibited the least adhesion loss, likely due to the pronounced cooling effect at the liner/steel interface.