Tire and vehicle makers could have an industry-approved tire aging standard and testing protocol by year-end 2006, thanks to the efforts of an American Society for Testing and Materials (ASTM) working group.
Working closely with the National Highway Traffic Safety Administration (NHTSA)-which will have the task of writing the standard-the ASTM task group is focused on defining optimal test conditions by year-end. And it hopes to have an industry-approved standard by year-end 2006, said June Satterfield, chairman of the group and industry standards/government regulations manager for Michelin North America Inc.
``ASTM believes the results of this project may aid NHTSA in writing a tire aging standard,'' Ms. Satterfield said. The task group's goal is not to set a baseline performance standard for aged tire durability, she added, but ``the organization that uses the standard is free to establish the pass/fail criteria it deems appropriate.''
The body-Tire Aged Durability Task Group within Committee F-09 of the ASTM-has 31 members representing 19 different organizations and every major stakeholder in the issue, including a NHTSA representative who sits in as an observer at its meetings, Ms. Satterfield said.
The committee's priority is to develop a laboratory test that artificially ages tires-particularly the belt wedge-that leads to the point of belt separation. However, it is taking care to avoid specific pitfalls.
``We don't want to create parasitic test failures, such as tread chunking, that don't occur in the field,'' she said. ``We don't want a test that fails a tire in a way that doesn't occur in the real world. We don't want to disproportionately age other parts of the tire, such as the bead area, which may become overbrittle with accelerated aging.''
Two different groups-a peer data subcommittee and the independent laboratory the task group hired-analyzed the data the task group generated, Ms. Satterfield said. After finalizing the data analysis, the group will move on to identifying significant statistical trends, such as which variables influence changes in material properties.
Ford Motor Co., a member of the task group, is making its independent field data on tire aging available to the group, and other organizations may do so as well, she said.
The ASTM test group's efforts are devoted entirely to tires on the road, Ms. Satterfield said. It does not consider the effects of aging on spare tires or on tires stored in warehouses or tire dealerships.