METHOD FOR GAS VULCANIZATION OF RUBBER TIRE

摘要

PURPOSE:To prevent the lowering of the heat transfer of a vulcanizing apparatus and to reduce the temp. difference between the upper and lower parts of a tire by intermittently injecting high pressure inert gas in the vulcanizing apparatus to hold the vulcanizing pressure in the vulcanizing apparatus to a definite range and stirring the steam in the vulcanizing apparatus. CONSTITUTION:The steam in a bladder 6 supplies heat to a tire 2 during vulcanization to become condensed water 1 and this condensed water 1 is accumulated in the lower side wall part 3 of the tire 2. Since the specific gravity of high temp. steam 4 is lower than that of supplied nitrogen gas 5, said steam gathers to the upper part of the bladder 6. When the vulcanizing pressure in the bladder 6 lowers to a certain degree to reach a prescribed value or less in this state, this pressure drop is detected by a pressure switch 7 and an air operation type cut-off valve 8 is opened to send the high pressure nitrogen gas 5 into the bladder 6. When the vulcanizing pressure in the bladder 6 becomes the prescribed value, this pressure rise is detected by the pressure switch 7 and the air operation type cut-off valve 8 is closed to hold the vulcanizing pressure to a definite range. As mentioned above, by stirring the steam in the bladder 6 by intermittently injecting the high pressure nitrogen gas 5 in the bladder 6, the temp. difference between the upper and lower parts of the rubber tire 2 at the time of vulcanization can be reduced.