Peeling of cord-rubber composites having relatively thick adherend.

Abstract

For thin film peeling such as pressure sensitive adhesive tape, peel strength(P/b) is mainly dependent on peel angle. However, the peel strength is also dependent on ply thickness as well as peel angle for a relatively thick multiplied specimen like a tire.In this study, peel test was conducted to find out the effects of thickness of specimen and peel angle on peel stength using two types (symmetric and asymmetric) of specimen having the relatively thick adherend. Peel angle of the specimen during peel test depended on the its thickness in symmetric pad specimen. The peel strength varied with the value of ρ/(ρ+ts) using a general peel theory, where ρ and ts were curvature radius and thickness of the specimen, respectively. In case of asymmetric pad specimen, the peel strength decreased with increasing thickness of one side of the specimen. From the plot of peel strength and thickness (or peel angle) for a certain asymmetric specimen, we can compare with the peel strengths between the different tire constructions having same ply components by measuring each peel angle.On the other hand, fracture energy and y-intercept were also measured on the plot of initial peel strength versus l/(ρ/(ρ+ts)-cosθ). This fracture energy was a constant value not affecting by change of peel angle, and can be also used as a representative value of fracture properties for a cord- rubber composite. The y-intercept meant the difference between initial peel strength and peel strength obtained during continuous peeling process. Finally, to evaluate fracture energy at the continuous peeling process, a new holder which makes a peel angle constant during a peel test needs to be designed.