Tire release agents.
A tire begins its long, hard life as "green tire." It is first assembled in the factory by a tire building machine from steel rings and prefabricated rubber component containing fillers, cords and steel belt. A cross-ply green tire is cylindrical in shape and a radial-ply tire has a pre-cambered form.
Before the green tire can become a fully fledged member of the mile-eating tire family, it has to undergo a crucial step, i.e., vulcanization in a curing press, which also doubles as a mold.
To give it its tread, the still-tacky green tire has to be forced to conform to the tread pattern in the mold. This is accomplished by inserting a heated bladder into the tire and expanding it with live steam. The hot bladder also supplies, from the inside, some of the heat required for complete vulcanization. The tire is heated simultaneously from inside and outside at temperature of 190[degrees]C. After about ten minutes, it is fully cured and, after being allowed to cool briefly, is removed from the mold.
To prevent the tacky green tire from bonding to the bladder during curing, silicone release agent is applied to the tire inside or the bladder beforehand. And to ensure that the cured tire is also ejected cleanly from the curing press, a release agent is often applied to the outside of the green tire as well.
The tire release agent, as a water-based dispersion, is sprayed in a very fine mist onto the inside of the tire by a machine.
The band-ply lubricant contains a silicone that is said to feature extremely good release, lubrication and heat resistance.
Circle 8 on card
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|Title Annotation:||Case Studies|
|Date:||Jun 22, 2004|
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