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 or black and white). The granulate is sized by passing through a screen, the size based on a dimension (1/4 inch) or mesh (holes per inch : 10, 20, etc.). Crumb rubber is often used in artificial turf as cushioning. 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 or black and white). The granulate is sized by passing through a screen, the size based on a dimension (1/4 inch) or mesh (holes per inch : 10, 20, etc.). Crumb rubber is often used in artificial turf as cushioning. The first synthetic grass was placed over concrete in 1964 and became known as “Chem Grass”. It was later named 'AstroTurf' when it was installed in the Houston Astrodome in 1966. Athletes did not like playing on these fields because it was dangerous. A new artificial turf system was developed in the early 2000s based on 'crumb rubber.' The black crumbs are small pieces of styrene-butadiene rubber made from grinding up old vehicle tires. The tire crumbs are poured in between the artificial grass blades, giving the artificial fields more cushion and support. This reduced major injuries compared to AstroTurf. Rubberized asphalt is the largest market for crumb rubber in the United States, consuming an estimated 220 million pounds (100 kt), or approximately 12 million tires annually. Crumb rubber is also used as ground cover under playground equipment, and as a surface material for running tracks and athletic fields. The following are common classifications of crumb rubber: