A new standard being finalized by ASTM Committee G02 on Wear and Erosion measures the wear resistance, or “sliding wear” of plastics. Expected to be available this summer, the proposed Test Method for Ranking Resistance of Plastics to Sliding Wear Using Block-on-Ring Wear Test—Cumulative Wear Method, will apply to thousands of plastic components from plastic gears used in washing machines to the plastic casings holding cellular phone antennas.

Created by a task group of ASTM Subcommittee G02.40 on Non-Abrasive Wear, the standard utilizes a block-on-ring friction and wear tester that ranks plastics according to their sliding wear characteristics against metals or other solids. Any material that can be fabricated into, or applied to blocks and rings can be tested.

The potential material combinations are endless. As well as consumer appliances, the test method can be used for automotive and aerospace parts, or any plastic exposed to friction wear. “Gears, bearings, cam shafts, all those are plastic components that experience sliding wear,” says Brian Holtkamp, a mechanical engineer and director of Testing Services with Falex Corporation, Sugar Grove, Ill.

The task group of mechanical engineers, plastic industry professionals, and academics specializing in materials testing redesigned a former block-on-ring test that covered metals as well as plastics. “A longer test time was found to be necessary to produce consistent, repeatable wear data,” says Holtkamp, who co-chairs the task group with Ray Bayer, a tribology consultant from Vestal, N.Y. “The block-on-ring test geometry on the books for a number of years was written for both metals and plastics. We found out that the plastics responded differently.” The test can be run with different gaseous atmospheres and elevated temperatures, as desired, to simulate service conditions.

ASTM standards are available by calling Customer Service (610/832-9585), or through the Web site.

For further technical information, contact Brian Holtkamp, Falex Corporation, 1020 Airpark Dr., Sugar Grove, IL 60554 (630/556-3669), or co-chairman Raymond Bayer, 4609 Marshall Dr. W., Vestal NY 13850 (607/722-7916).

Committee G02 meets Nov. 15-17 in Orlando, Fla. For meeting or membership details, contact manager Timothy Brooke, ASTM (610/832-9729; fax: 610/832-9666). //

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