A Towing Device for Estimating Road Wear

Abstract

Abstract The towing device was designed to provide a rapid screening test that might be applied to measure the wear resistance of small quantities of experimental polymers. The reproducibility of the test has been found to depend to a large degree upon the care was taken to design measuring equipment that would provide a good estimate of this value. The nature of the road surface will produce a change in the rate of wear and, with certain polymers, excessive cutting has been encountered that affected the reproducibility of the measurement. This difficulty may be avoided by selecting a smoother road surface and longer test runs may be employed without increasing the duration of the test beyond 6 hours. A towing device has been developed that allows the wear resistance of a small quantity of polymer to be evaluated by towing a test wheel at a slight angle over the surface of a road at normal tire loads and speeds. Data from road wear tests of tires of various sizes showed that a log-log plot of the volume loss per unit width of tread of the experimental against the control vulcanizate gave a single correlation. The volume loss of the control vulcanizate may be taken as a measure of the severity of the test. Tests using the towing device at various angles of tow gave data that showed a correlation of wear values similar to that found in road tests. The towing device provides an adequate method for screening the wear qualities of small quantities of experimental polymer.