|(Photo: Amerityre Corp.)|
Will Polyurethane Replace Rubber?
BOULDER CITY, NV (Jan. 2, 2006) - Rubber has ruled the automotive tire industry for more than a century. That may be about to change, with new patented technologies that, for highway and agricultural tires, may lead to the replacement of traditional rubber with Amerityre Corp.'s Elastothane tires.
Like petroleum, rubber has a limited and decreasing supply that has led to the search for alternative materials. During World War II, where most rubber producing areas were under the control of the Japanese, the U.S. government pushed for and tire makers responded with all-synthetic rubber tires, in the event they were needed. Between then and today, other technologies to replace rubber with an improved tire at a lower production cost were tried, including advanced polymers and even nanotechnology-based materials, but each innovation fell short of reaching the mark.
Persistence pays dividends
As one of the companies involved earlier with advanced polymer-based tires, Amerityre had been able to make polyurethane tires for bicycles and smaller outdoor use wheels that did make it to market. In the years since then, the company turned its focus to developing automobile tires, knowing a number of earlier problems needed to be faced and overcome.
These included meltdown under braking, traction (especially on wet surfaces), hydroplaning and heat (which could limit top end driving speed), to name a few. Craig Hooks, sales and marketing manager for Amerityre explained that unlike other tire manufacturers, the company researched the problems and used its expertise to overcome each of them, culminating in the development of a tire made from polyurethane elastomers.
To look at a cross-section of a Elastothane tire, it resembles a traditional rubber tire in that there are plies, beads and belts. That is where the similarities end. There is no rubber present. The manufacturing process can be described as being more like more like making reinforced concrete than rubber tires.
Reinforcement materials such as fibers or wires are used for plies, belts and beads, and are suspended inside a mold. Liquid polyurethane - blended from the mixing of two chemicals, polyol and diisocyanate - is then poured around the reinforcements. Through a spinning process, the blend surrounds and encapsulates them in one monolithic piece. Every finished tire has the exact round shape of the mold and is identical to the others.
|The ARCUS Prototype Elastothane tire.|
(Photo: Amerityre Corp.)
In April 2004, Amerytire's regular-sized Elastothane ARCUS prototype tire passed the U.S. Department of Transport's Federal Motor Vehicle Safety Standard (FMVSS) Rule 109 tests for heat, endurance and aging. Hooks added, "We not only passed the test, we did so with flying colors."
He also noted this was the first time a polyurethane tire had passed the rigorous testing. Compared to a control tire used - a run-flat tire used on Corvettes - the ARCUS ran an average of 56