Factors affecting adhesion of natural rubber-to-brass plated steel wire

The wide use of wire-reinforced rubber products such as conveyor belts, hose and radial ply tyres has reawakened interest in the parameters affecting the adhesion of rubber to brass plated steel wire. My research work is an attempt to improve and explain the rubber to metal bonding technology; it is concerned with the effect of rubber compounding ingredients as well as wire surface factors on adhesion. This work pertains to show the role played by two of the recently introduced and widely used bonding systems namely (i) Hexamethylene tetramine-resorcinol system and (ii) the Triazine system (Vulcabond SW)* on the adhesion of the rubber to brass plated steel wire. Different carbon blacks, as well as different accelerators and silica are shown to have a great influence on the amount of rubber adhesion to brass plated steel wire. The state of the wire plating as well as the contamination of its surface affects bonding and these parameters were studied using the scanning electron microscope. XPS techniques are employed to explain the role of some accelerators in the mechanism of bonding rubber to brass plated steel wire. A relationship has been found to exist between bind strength and rubber fracture properties. Because of the widespread use of radial tyres in the automobile industry and in every field in which heavy types of tyres are used, this research considers in detail the phenomena of fatigue and pressure at various temperatures on bond life. Also wire ageing is considered to be very important and to effect the bond between the rubber and the brass plated steel. * Trade name of Vulnax International Ltd.