A method and system for applying a sealing agent to a surface (2) of an inner cavity (3) of a pneumatic tyre; the method provides for detecting the weight of the pneumatic tyre (4) before and after the application of the sealing agent to the surface (2); calculating the difference between the quantity of sealing agent applied to the surface (2) and a reference quantity of sealing agent, storing said difference within a short-term memory buffer (24) and a long-term memory buffer (26); determining a short-term compensation factor (K.sub.ST) and a long-term compensation factor (K.sub.LT) and calculating a correction factor (K.sub.EA) using alternately the short-term compensation factor (K.sub.ST) or else the long-term compensation factor (K.sub.LT); and using said correction factor (K.sub.EA) to actuate an applicator device (7) during the subsequent step of applying the strip of sealing agent to the surface (2).

A method for forming a tire having a composite innerliner is described wherein the method includes the following steps: forming a coextruded strip of a first compound and a second compound, wherein the first compound may be an air impermeable compound, and the second compound is a cross linkable diene rubber compound, winding the coextruded strip onto a tire building drum while varying the ratio of the first compound to the second compound to form an inner liner layer of spirally wound coextruded strips.

One or more embodiments of the present invention provide a tire and method of forming a continuous encapsulated strip of sealant layer inside the tire. The strip of sealant layer has a varied mixture ratio of the sealant compound to the skin compound.

A method of selectively controlling the self-sealing ability of a tyre obtained by application of a sealing assembly on a drum and subsequent formation thereon of a precursor of a green tyre inclusive of liner and carcass, followed by shaping, curing and molding. The sealing assembly includes: a self-supporting thermoplastic film of polyamide or polyester and a layer of sealing material possessing viscoelasticity and stickiness features, which is associated with and supported by the self-supporting thermoplastic film. The sealing assembly is easily puncturable by a sharp-pointed element while it maintains such a deformability and stickiness that it helps in the transfer of the sealing material during ejection of the sharp-pointed element and limits the transferred material amount to such an extent that holes bigger than a predetermined value are not sealed.

The present invention relates to a self-sealing tyre for vehicle wheels comprising at least one carcass ply, a tread band applied in radially outer position to said carcass ply in a crown zone, optionally a liner applied in radially inner position to said carcass ply, a sealing composite applied in radially inner position to the liner and axially extended at least at a part of the crown portion of the tyre; wherein said sealing composite comprises a self-supporting thermoplastic film comprising at least 50% by weight with respect to the weight of the film itself of at least one or more polyolefins, wherein the at least one polyolefin has a fluidity index (MFI) of less than 4 gram per 10 minutes, and a sealing composition layer associated with and supported by said self-supporting thermoplastic film.

A method and system for applying a sealing agent to a surface (2) of an inner cavity (3) of a pneumatic tyre; the method provides for detecting the weight of the pneumatic tyre (4) before and after the application of the sealing agent to the surface (2); calculating the difference between the quantity of sealing agent applied to the surface (2) and a reference quantity of sealing agent, storing said difference within a short-term memory buffer (24) and a long-term memory buffer (26); determining a short-term compensation factor (K.sub.ST) and a long-term compensation factor (K.sub.LT) and calculating a correction factor (K.sub.EA) using alternately the short-term compensation factor (K.sub.ST) or else the long-term compensation factor (K.sub.LT); and using said correction factor (K.sub.EA) to actuate an applicator device (7) during the subsequent step of applying the strip of sealing agent to the surface (2).

A system is provided for applying a sealing agent to an surface of an internal cavity of a pneumatic tire. The system provides for detecting the weight of the pneumatic tire before and after the application of the sealing agent to the surface, calculating the difference between the quantity of sealing agent applied to the surface and a reference quantity of sealing agent; storing the difference within a short-term memory buffer and a long-term memory buffer; determining a short-term compensation factor and a long-term compensation factor and calculating a correction factor using alternatively the short-term compensation factor or else the long-term compensation factor; and using the correction factor to actuate an applicator device during the subsequent step of applying the strip of sealing agent to the surface.

A method of selectively controlling the self-sealing ability of a tire obtained by application of a sealing assembly on a drum and subsequent formation thereon of a precursor of a green tire inclusive of liner and carcass, followed by shaping, curing and molding. The sealing assembly includes: a self-supporting thermoplastic film of polyamide or polyester and a layer of sealing material possessing viscoelasticity and stickiness features, which is associated with and supported by the self-supporting thermoplastic film. The sealing assembly is easily puncturable by a sharp-pointed element while it maintains such a deformability and stickiness that it helps in the transfer of the sealing material during ejection of the sharp-pointed element and limits the transferred material amount to such an extent that holes bigger than a predetermined value are not sealed.

A method of selectively controlling the self-sealing ability of a tyre obtained by application of a sealing assembly on a drum and subsequent formation thereon of a precursor of a green tyre inclusive of liner and carcass, followed by shaping, curing and molding. The sealing assembly includes: a self-supporting thermoplastic film of polyamide or polyester and a layer of sealing material possessing viscoelasticity and stickiness features, which is associated with and supported by the self-supporting thermoplastic film. The sealing assembly is easily puncturable by a sharp-pointed element while it maintains such a deformability and stickiness that it helps in the transfer of the sealing material during ejection of the sharp-pointed element and limits the transferred material amount to such an extent that holes bigger than a predetermined value are not sealed.

A system is provided for applying a sealing agent to an surface of an internal cavity of a pneumatic tire. The system provides for detecting the weight of the pneumatic tire before and after the application of the sealing agent to the surface, calculating the difference between the quantity of sealing agent applied to the surface and a reference quantity of sealing agent; storing the difference within a short-term memory buffer and a long-term memory buffer; determining a short-term compensation factor and a long-term compensation factor and calculating a correction factor using alternatively the short-term compensation factor or else the long-term compensation factor; and using the correction factor to actuate an applicator device during the subsequent step of applying the strip of sealing agent to the surface.