  The double peeling of detachment of non-linear adhesive tapes from a flat
Poly(methylmethacrylate) (PMMA) surface has been investigated from both
experimental and theoretical point of view. Double peeling tests show that, as
the detachment process advances, the peeling angle stabilizes on a limiting
value {\theta}lim corresponding to a critical pull-off force Fc above which the
tape is completely detached from the substrate. This observed behavior is in
good agreement with results obtained following the new theory of multiple
peeling and taking into account the hardening-softening non-linear behavior of
the experimentally tested adhesive tapes and clarifies some aspects of the
experimental data. In particular, the theoretical model shows that the value of
the limiting peeling angle depends on the geometry of the adhesive tape as well
as on the stiffness properties and on the interfacial energy {\Delta}{\gamma}.
Finally, theoretical predictions confirm that solutions with a peeling angle
lower than {\theta}lim are unstable.
