With 26 members in three countries, the Pico Abrasion Task Group of ASTM Committee D11 on Rubber has collaborated over the past 18 months to revise the pico abrasion method, D 2228, Test Method for Rubber Property—Abrasion Resistance Pico Abrader. Key revisions being balloted this month are new ingredients and specifications for cutting knives.

In June in Norfolk, Va., the task group agreed on viable changes to the popular test method which was developed in 1988.

New calibration compound ingredients have been introduced. “Certain ingredients, formerly available from NIST and other sources are now available through ASTM as IRMs [industry reference materials] and from new suppliers,” said task group chairman Michael Kent Warner, the Special Projects manager with CCSi, Inc., Akron, Ohio. These standardized ingredients, such as process oils and carbon blacks, are available for compounding rubber and other materials and are now included in the revised ‘Table A1.1 Formulas for Calibration Compounds.’”

In the Pico Abrader test, rubber specimens are scraped with knives to determine their resistance to abrasion, Warner explained. On the issue of cutting knives, testing was conducted by the task group on used, resharpened, and new blades. “The current specification on the knife edge calls out 10–12µ,” he said, noting that in the testing performed by the task group, “the resharpened blades were 15µ and the new were 5µ [and] the results were remarkably similar! This led to a discussion about opening up the knife edge specification to 10µ ± 5µ. The rationale being that this would reduce the manufacturing/resharpening cost. Also, since the method states that the blades can be used until they reach 20µ, the tightness of the spec is probably unnecessary as that is the purpose of employing the calibration compounds to begin with.” Part of Subcommittee D11.15 on Degradation Tests, the task group decided to verify the dimensions through interlaboratory test programs employing new, resharpened, and used blades.

For further technical information, contact Michael Kent Warner, CCSi, Inc., Seattle, Washington (phone: 360/697-6993). Committee D11 meets Dec. 3-6, Dallas, Texas. For meeting or membership details, contact Tim Brooke, manager, ASTM Technical Committee Operations (phone: 610/ 832-9729). //

Copyright 2001, ASTM