Technology to Separate Rubber Crumb From Fiber

Tests at a research laboratory and field evaluation at a commercial tire recycling facility demonstrated thereliability and economic value of a new machine to separate the waste fluff produced by tire recycling plants into marketableproducts such as crumb rubber and fiber. Two new fluff recycling machines were designed, constructed, patented, and testedin the lab (prototype and improved), and one (prototype) was tested in a commercial plant. Processing the fluff from severalrecycling plants with the prototype machine yielded from 34% to 87% crumb and from 1% to 26% fiber. The crumb was mostly300 microns or smaller. The quantity of un-ground rubber in the fluff ranged from 2% to 64% and greatly impacted the amountof recoverable crumb and fiber. Field tests at a commercial tire recycling facility were successful and the prototype machineyielded 70% crumb, 13% clean fiber, 9% partially cleaned fiber, 5% large pieces of un-ground rubber, and 3% cyclone waste.Evaluation of the improved machine with fluff from five recycling plants produced 40% to 67% crumb, mostly 300 micronsor smaller. The highly variable raw material yielded from 1% to 21% clean fiber, 9% to 30% rough fiber, and 3% to 48%un-ground rubber. Economic evaluation for three tire recycling plants that processed between 2 and 5 million tires annuallyindicated that their gross income could be increased from $0.67 to $1.94 million per year depending on the quantity of tiresprocessed and the landfill costs. The machines process about 1490 kg/h/m (1000 lb/h/ft) of width and cost about $100,000.