The cushion gum is cured in an autoclave, to fix the tread to the casing. Before curing, a bladder is fitted inside the
tyre and a rubber envelope outside the tyre. Once inside the autoclave, differential pressure, usually steam, is
applied to the envelope, at about 85 psi, and the bladder, at about 110 psi. This ensures close adherence of the
tread to the casing. Curing may take three to four hours at a temperature of just under 100°C. The main hazards are
associated with pressure systems, and rubber fume from curing.