Ways of the complete ambient grinding process Essay

The complete ambient grinding process is usually accomplished with open mills, granulators, extruders, or hammer mills. All grinding take place at room temperature also referred to as ambient conditions. The actual particle reduction is accomplished by a tearing, ripping, or smashing action. This creates a particle with a rough surface, perhaps described as spongy.
Ambient grinding can be accomplished in two ways granulation or cracker mills. In an ambient system, the rubber, tires or other feedstock remain at room temperature as they enter the cracker mill or granulator.Ambient grinding is conducive to any size particle, including whole tires. It can be accomplished in two ways granulation or cracker mills. In an ambient system, the rubber, tires or other feedstock remain at room temperature as they enter the cracker mill or granulator.
Ambient grinding is a multistep processing technology that uses a series of machines (usually three) to separate the rubber, metal, and fabric components of the tire. Whether using granulation equipment or cracker mills, the first processing step typically reduces the original feedstock to small chips. The second machine in the series will grind the chips to separate the rubber from the metal and fabric. Then a finishing mill will grind the material to the required product specification. After each processing step, the material is classified by sifting screens that return oversize pieces to the granulator or mill for further processing. Magnets are used throughout the processing stages to remove wire and other metal contaminants. In the final stage, fabric is removed by air separators.Rubber particles produced in the granulation process generally have a cut surface shape and rough texture, with similar dimensions on the cut edges. Uses for the crumb rubber or granulate produced in this process include safety and cushioning surfaces for playgrounds, horse arenas and walking/jogging paths.
Cracker mills  primary, secondary or finishing mills are all very similar and operate on basically the same principle they use two large rotating rollers with serrations cut in one or both of them. The roll configurations are what make them different. These rollers operate facetoface in close tolerance at different speeds. Product size is controlled by the clearance between the rollers. Cracker mills are low speed machines operating at about 3050 RPM. The rubber usually passes through two to three mills to achieve various particle size reductions and further liberate the steel and fiber components.
These mills do not have screens built into the mill and as such the mill itself does not control the final particle. A standalone screening system will separate sized particles from oversize granules following the mill and recirculate the oversize products. The crumb rubber particles produced by the cracker mill are typically long and narrow in shape and have a high surface area.
Crumb or ground rubber produced in this process is used in the manufacture of numerous rubber products. These include mats for domestic, commercial, recreational, industrial and agricultural use rubber wheels for carts and lawnmowers insulation products lumber and other construction products.