Delamination is a process in which the tyre, for various possible reasons, separates into its component parts. Running for a considerable time in an underinflated or overloaded condition is the single largest cause of tyre delamination. The most commonly seen examples of delamination are the tread sections of broken lorry tyres found discarded on the sides of British motorways after a blow-out.
These eyesores are usually initially caused by the tyre suffering a slow deflation over time. When pressure continues to drop, the pressue of air inside the tyre becomes insufficient for the loads and stresses placed upon it. Heat then builds up within the stressed tyre walls, leading to delamination which in turn causes the tyre to break, with potentially fatal consequences.