Tire with double layer innerliner

A method of making a pneumatic tire, comprising:

• assembling a first green innerliner layer on a green tire carcass and a second green innerliner layer on the first green innerliner layer to form a green tire assembly, wherein the second green innerliner layer comprises a second rubber compound and a nitrogen-releasing foaming agent dispersed therein, and wherein the first green innerliner layer comprises a first rubber compound without a foaming agent therein;
• placing the green tire assembly in a curing mold with the second green innerliner layer furthest from the mold surface;
• expanding a curing bladder against the second green innerliner layer to press the green tire assembly into the mold surface while applying a vulcanization temperature in the mold, wherein nitrogen gas is released upon decomposition of the foaming agent in the green second innerliner layer to form a cured tire assembly comprising a non-foamed first innerliner layer adjacent the tire carcass and a foamed second innerliner layer at an innermost surface of the tire;
• deflating the curing bladder and stripping the curing bladder from the foamed second innerliner layer;
• and
• thereafter, forming an open-cell structure in the innermost surface of the foamed second innerliner layer by physically altering the innermost surface by one of cutting the innermost surface with a knife to open a cellular structure of the foamed second innerliner layer or perforating the innermost surface with a laser, to form a plurality of open cavities, wherein the physically altering forms the plurality of open cavities with a mean diameter of about 50-250 μm.

A method of making a pneumatic tire, comprising:

• assembling a first green innerliner layer on a green tire carcass and a second green innerliner layer on the first green innerliner layer to form a green tire assembly, wherein the second green innerliner layer comprises a second rubber compound and a nitrogen-releasing foaming agent dispersed therein, and wherein the first green innerliner layer comprises a first rubber compound without a foaming agent therein;
• placing the green tire assembly in a curing mold with the second green innerliner layer furthest from the mold surface;
• expanding a curing bladder against the second green innerliner layer to press the green tire assembly into the mold surface while applying a vulcanization temperature in the mold, wherein nitrogen gas is released upon decomposition of the foaming agent in the green second innerliner layer to form a cured tire assembly comprising a non-foamed first innerliner layer adjacent the tire carcass and a foamed second innerliner layer at an innermost surface of the tire;
• deflating the curing bladder and stripping the curing bladder from the foamed second innerliner layer;
• and
• thereafter, forming an open-cell structure in the innermost surface of the foamed second innerliner layer by physically altering the innermost surface by scanning the innermost surface with a pulsed laser, to perforate the innermost surface thereby forming a plurality of open cavities with a mean diameter of about 50-250 μm.