RELATIONSHIP BETWEEN THE COHESIVE STRENGTH AND THE TACK OF ELASTOMER .2. CONTACT TIME EFFECTS

The self-tack (also called autohesion or simply tack) of an elastomer is its ability to resist separation from another piece of the same elastomer compound with which it has been brought into contact for a short time under a light pressure. If the two contacted elastomeric layers are uncrosslinked, then the interface between them will eventually disappear and the strength of the junction (tack bond) will become identical to the cohesive strength of the material. The process has been referred to as 'healing'. In this paper, studies of the rate and temperature dependence of bond strength are extended to include tack bonds possessing varying degrees of healing. This was simply achieved by varying the contact time before measuring tack.