Seal strength evaluation of flexible plastic films by machine testing and human peeling

The seal strength of flexible packaging indicates both functional performance and the ease of opening. This research aims to compare the seal peeling mechanisms evaluated by human participants and standard machine tests. The tests were conducted on flexible films used for typical packaging applications, LDPE, LLDPE and Nylon/LLDPE. Human peeling was simulated through the use of novel force measurement equipment. The results showed that the maximum machine peel force set by standard test methods was generally lower than the human peel force for most sealing temperatures. In all film types no significant difference was shown between genders although for people over 65 years peel force was generally lower than for the younger cohort. The results also indicated that peeling speed of human participants was normally higher than the peeling speed set according to the machine test standard.