Ageing of Rubber parts: Ageing often results in a change in physical parameters such as tensile strength and hardness. Ageing is divided into these two categories: • shelf-ageing • atmospheric ageing.

Shelf-ageing is basically oxidative degradation. Apart from the obvious influence of oxygen, the catalytic effects of heat, light, internal and external stresses or strains and pro-oxidant metals should be considered.As opposed to shelf-ageing, atmospheric ageing is characterized by the attack of ozone on the rubber.