Siping (rubber) wear and extends the life of the tire. Both Bridgestone and Michelin sell snow tires that are siped at the factory, while Saf-Tee Siping and Grooving sells machines that can sipe most standard vehicle tires. Siping can also be done by hand. Siping tires may void the manufacturer's warranty. Claims that extended life is achieved by siping may only apply to certain environments, operating temperatures, and rubber compound builds. Siped soles are a characteristic feature of boat shoes. Siping (rubber) Siping is a process of cutting thin slits across a rubber surface to improve traction in wet or icy conditions.
Crumb rubber PAHs were found to be elevated as well. The levels of most of these compounds were higher than background but were below levels regulated in waterways for environmental protection. Crumb rubber Crumb rubber is recycled rubber produced from automotive and truck scrap tires. During the recycling process, steel and tire cord (fluff) are removed, leaving tire rubber with a granular consistency. Continued processing with a granulator or cracker mill, possibly with the aid of cryogenics or by mechanical means, reduces the size of the particles further. The particles are sized and classified based on various criteria including color (black only