Abstract:
In a process for manufacturing, moulding and curing tires for vehicle wheels without a vulcanization bladder, many drawbacks can result from a direct contact between the green tire and the fluid under pressure admitted in order to create the necessary pressing of the elastomer material against the vulcanization mould walls. In accordance with the present invention, said drawbacks are avoided by including in the tire manufacturing process a step of treating the inner surface of the green tire in order to prevent the permeation of the fluid under pressure into the inside of the tire structure. Said treatment can be carried out by associating at least one layer of prevulcanized elastomer material with the inner surface of the green tire.
Abstract:
A tire for vehicles includes a tread having a vulcanized polymeric base including at least one reinforcing filler dispersed in the polymeric base; an amount of extractable residue of at least one vulcanization accelerator, containing at least one carbon atom bound to at least two sulfur atoms, from 0.5% to 1.8% by weight based on a total weight of the tread; an amount of at least one activator, expressed as equivalents of zinc oxide, not higher than 2% by weight based on the total weight of the tread; and an amount of combined sulfur lower than 2.5% by weight based on the total weight of the tread. A tread for vehicle tires, a vulcanizable rubber composition for the manufacture of such a tread, and a vulcanizing system, all related to the tire for vehicles, are also disclosed.