White Wall Grinder
Tire White Wall Grinder
While rarely produced anymore, white wall tires and those with raised white letters used to be very popular. A tire white wall grinder was used to remove the black layer of rubber over the white layer as part of the manufacturing process. In essence, to reveal the white layer behind the black.
This sketch shows a QB3 proportional valve inflating the tire and maintaing the ideal pressure throughout the grinding process. A second QB3 is controlling pressure to the cylinder that is applying force to the tire. The force must be precise and consistent, or the grinder will remove too much and ruin the tire.
The QB3 is able to repond quickly because it offers high forward and reverse flow rates. This keeps the grinder at the exact force required to remove the specific layer.