The Relation between Tack of Uncured Rubber Compound and Elastic Contact
Asahiro AHAGON
Mitsuhiro IWATA
R & D Center, The Yokohama Rubber Co., Ltd., Kanagawa, Japan
Nippon Gomu Kyokaishi,(2004),77(11),382-387 Original Paper in Japanese

Dependence of tack on contact force, contact time and surface roughness was studied using a Br-IIR compound. The results suggested that the tack of the uncured rubber compound was determined by bond forming and bond destruction processes.
The observed tack values were examined by means of the Hertz's elastic contact theory. Tack was found proportional to , W and G(t) being the contact force and the time dependent shear modulus of the material to account for the contact time dependence, in accordance with the theory. This indicated that the true contact area during bond formation was the major factor determining the tack, and that the contact time dependence was caused by the creep taking place at the pairs of contacting surface protrusions. Given the effectiveness of the theory to evaluate the true contact area, the effect of surface roughness was examined. An extra contribution to tack, in addition to that determining the contact area, from the number of the surface protrusions appeared to exist. It was considered attributable to viscous dissipation upon mechanically detaching the bond.

(Received on December 10, 2003)
(Accepted on September 27, 2004)

Tack, Elastic contact, Surface roughness