Polyurethane Compounds Outperform Rubber

Polyurethane tyre manufacturer, Amerityre, has claimed that its products out perform “comparable rubber compounds” when it comes to heat aging and Ozone resistance. The claim follows testing at an independent laboratory in accordance with ASTM test standards. Amerityre explains that it tested its products for these attributes in anticipation of NHTSA standardised testing, including an “oven-aging test” due to take effect in July 2007.

Amerityre reports that the tested polyurethane material demonstrated a nominal increase in hardness of zero to 2 per cent after 70 hours of testing at high temperature (100 degrees Celcius). Tests on comparable rubber compounds showed increases in hardness ranging from 12 per cent to 20 per cent. In ozone testing [50pphm ozone, under ASTM D1149], Amerityre reports that the polyurethane material had no cracking after 144 hours, while the rubber compounds showed initial cracking as soon as 30 hours. Increased hardness and cracking are both indicators of potential performance degradation.

According to Richard Steinke, Amerityre’s president and CEO, the test results demonstrate that the use of Amerityre’s polyurethane materials could be a very effective solution in helping tyre manufacturers combat the effects of heat aging and ozone exposure on tyres. Mr Steinke believes that the use of Amerityre’s polyurethane materials can be expected to produce a tyre that is more consistent during its lifetime.

Amerityre has developed proprietary compounds and patented manufacturing processes for the production of polyurethane passenger car tyres. The results of the Amerityre polyurethane material testing are significant in that they demonstrate that Amerityre polyurethane compounds show minimal changes in physical properties as a result of extended exposure to heat and ozone. How the tyres fair in terms of other attributes, and most importantly customer perception, remains to be seen.