High speed measurements of dry adhesion as related to the friction and abrasion of elastomers

Abstract

AbstractStudies of friction and abrasion of elastomers have indicated that static friction or adhesion may be one of the important parameters in the traction and wear obtained with automobile tires. In this case static friction is considered to exist where a point of contact, adhesive attachment, or an interlocking is made between the rolling tire and the road which is strong enough to hold and transfer energy from one surface to the other. To investigate the magnitude of adhesion between tire tread rubber and the road, a test was developed that would measure the dry adhesion of rubber to other materials at break‐away speeds above the recovery rate of the rubber. By using clean dry surfaces and break‐away speeds of 2000 in./min., adhesive values in the order of 100 psi were measured with butyl tread stocks against impact styrene or against a rough stone surface. Much lower values were obtained for SBR and natural rubber. The influence of surface contamination, break‐away velocity, and hysteresis was also studied. The equipment used and the procedures for these tests are described in this paper.