Hard Rubber/Metal Adhesion Assessment Using a Heavy Cylinder Rolling Test

Abstract

When an elastomer is put into contact with a rigid substrate, a certain adhesion, or adherence may develop at the interface. This effect is beneficial under some circumstances, such as in the case of a vehicle tyre in contact with a road surface. In other cases, adherence can cause problems. For example, when a water tap has been left closed for too long, the adhesional force of the rubber washer to metallic components can be superior to the cohesional strength of the elastomeric material and subsequent opening of the tap leads to the washer tearing. A high degree of adhesion may be apparent even at room temperature if the contact time and pressure are sufficient. Nevertheless, a necessary condition for long term adhesion is good initial or spontaneous contact. The present study considers this spontaneous adhesion between a steel substrate and two types of elastomer, both containing carbon-black. A heavy cylinder rolling test has been developed. Cylinder rolling tests have previously been used to study soft rubbers [1]. However, the elastomers employed in the present context are relatively hard and a high contact pressure is therefore necessary in order to ensure intimate steel-elastomer contact. This leads to the fact that the energy dissipated during rolling is related not only to the hysteretic effects accompanying adherend separation but also to losses invoked by the stress field in the elastomer beneath the heavy cylinder.