Developments to Watch
ULTRASOUND SMOOTHES THE WAY FOR RECYCLING TIRES
Avraam I. Isayev wants to rid the landscape of used tires with an ultrasound make-over. Instead of breaking down tires with harsh solvents, the University of Akron professor strips them of nylon cord and steel belts and then treats them with high-pitched sound waves, heat, and pressure to quickly break their strong chemical bonds. Once the rubber is fluid, it can be shaped into other products or mixed with new rubber. Gaskets, hoses, and belts made of expensive, rubber-like compounds--which cost $10 to $20 a pound to buy new--also can be recycled. Isayev predicts his method will be cheaper in the long run because it doesn't use solvents, which are expensive to handle and dispose of.
Isayev says the system's capacity, now five pounds of rubber an hour, will be cranked up to 100 within a year--enough to handle small items, such as gaskets. Recycling tires will require a capacity of 5,000 or more pounds an hour, which will take longer to develop. National Feedscrew & Machining Industries in Massillon, Ohio, is funding the research and has a license to produce the equipment and recycle tires. EDITED BY RUTH COXETER