Slip-Stick Dynamics in Butyl Pressure-Sensitive Adhesive/Silicone Release-Liner Systems: Mean Apparent Separation Force and Peak Counting for Application-Specific Release-Liner Screening

This study evaluated how silicone release liners come away from butyl hot-melt pressure-sensitive adhesive (HMPSA) sealants. An application-specific integration peel test was conducted based on FINAT FTM 10 geometry. It kept the 180° geometry, the 300 mm/min crosshead speed, and the cN/25 mm reporting convention, but used 90 mm butyl-sealant strips in place of a standard reference adhesive tape. The reported values are therefore apparent/effective separation forces for the tested liner–butyl constructions, not standard FINAT datasheet release-force values. Three double-sided silicone-coated PET liners (Rossella, Dolpap, Crosil 42) and seven commercial butyl sealants (C1E, U2E, C1EN, T1E, T2E, T1EN, T2EN) were tested on both liner sides. Two descriptors summarized each force–displacement trace: the mean apparent separation force and an operational slip-stick peak count based on positive residual-force excursions. Most combinations stayed below about 18 cN/25 mm. An increase was observed for T1EN, and a much larger one for Rossella/U2E. In both cases, high, diffuse stress was accompanied by volumetric deformations, fibrillation, and unstable detachment, rather than clean detachment at the phase boundary. Dolpap was the most stable and the most symmetric. Crosil 42 stayed in the low-force range but showed a few material-specific side differences. Taken together, the mean force and the peak count form a reproducible relative screen for selecting actual liner–butyl pairs, one that complements rather than replaces standard release-liner datasheet testing.