TAMPA, FLA. - High performance polyurethanes founded on a Du-Pont Co. isocyanate have helped reduce replacement costs for one of the tallest roller coasters in the world and may help manufacturers serving high-wear markets, DuPont officials said. Hylene para-phenylene diisocyanate can be used in cast urethanes and thermoplastic elastomers for a variety of products, including mining equipment, amusement park wheels, rollers and other small specialty parts, said Carol Lyell, DuPont product manager for specialty diisocyanates.
Lyell discussed PPDI with urethane makers at DuPont's booth during the April 15 poster session at the Polyurethane Manufactur-ers Association's anniversary meeting in Tampa.
``We had a lot of interest,'' she said. ``We were able to talk to folks who didn't realize [PPDI] was fully commercial'' now.
DuPont is using the 225-foot tall Desperado roller coaster at Buffalo Bill's Resort & Casino in Primadonna, Nev., as an example of Hylene's benefits.
The coaster puts its wheels to the test with speeds up to 80 mph, twists and turns, severe desert conditions and temperatures as high as 130§ F, according to DuPont of Wilmington, Del.
That was too much for its old urethane wheels, which wore out in as little as 150 hours of use, according to the amusement park. The PPDI urethane doubled the roller coaster's wheel life and saves about $20,000 a season on wheel costs, not including the labor for wheel changes, the park said.
The urethane is made from Uniroyal Chemical Co.'s Adiprene PPDI prepolymer, part of a line of prepolymers based on DuPont's Hylene. Uremet Co. of Santa Ana, Calif., produces the wheels for the Desperado and has made PPDI urethane wheels for at least four major amusement parks.
DuPont currently has an annual capacity for 600,000 pounds of Hylene at a small plant in Deepwater, N.J., that was built in 1994. Uniroyal currently is the chief user of the chemical in prepolymers, but DuPont also sells to other suppliers, Lyell said.
Jeffrey Brown, a DuPont senior technical service consultant who also worked the company's booth at the PMA meeting, said PPDI's results are ``reasonably dramatic'' and its capabilities at high temperatures eventually may take urethane product makers under the automobile hood.
PPDI is more expensive, but ``it will add a lot of value to the urethane industry,'' he said.