Property profile of a laminated rubber bearing

Laminated rubber bearings consist of alternate layers of rubber and metal plates. During production, the time taken to mould the bearing is usually longer than the cure time of rubber as obtained from the rheometer test. A longer time is needed to allow the heat to reach the interior part of the bearing because of the poor conductivity of rubber. Prolonged exposure to heat may affect the physical properties of rubber. A study carried out on thick rubber bearings showed that prolonged exposure to heat during moulding created a property profile across the thickness of the bearing. Rubber properties such as modulus, tensile strength, elongation at break, hardness and compression set showed an improvement toward the interior parts of the bearing while the strength of rubber-to-metal bond did not show any significant difference. However, the variation in those properties did not make any significant changes to the compression and shear stiffness of the rubber bearing.