SECTION II
Testing with the Taber Abraser
SIGNIFICANCE AND USE
The Taber Rotary Platform Abraser is commonly
used to provide comparative data regarding the
abrasion resistance of a material.
It is important to recognize there may be several
factors that contribute to wear performance of
materials in actual use. Before predictions can
be drawn from laboratory tests, actual end-use
trials should be conducted. This helps establish
the relationship between the laboratory abrasion
test and actual wear in the intended end-use.
The consideration of additional factors is often
necessary in the calculation of predicted
durability from specific abrasion data. While
“abrasion resistance” (often stated in terms of
the number of cycles to produce a specified
degree or amount of abrasion) and “durability”
(defined as the ability to withstand deterioration
or wearing out in use, including the effects of
abrasion) are frequently related, the relationship
typically varies with different end uses.
Accelerated abrasion tests compress the life
span of a product into a much shorter duration in
a controlled and monitored environment. While
the test may not represent the actual conditions
materials are exposed to, lab tests can duplicate
many real world conditions, making it much
easier to reproduce the test. In addition, there is
greater flexibility with the methodology, costs are
significantly less, and you are able to test more
samples.
TESTING PROCEDURES
As you start your testing, use of these guidelines
should assist you in developing a test procedure
that will yield reproducible test results, accurate
within the variations of quality inherent in the
material itself.
Establishing a Test Procedure
The purpose of this section is to outline all the
elements of a typical test procedure from
analysis of the testing problem to final evaluation
of results. Knowledge of the mere mechanics of
testing, the preparation and mounting of
specimens, and the setup and operation of the
Abraser is presumed. That phase of testing has
been treated in detail in other sections of this
manual. Where it is appropriate, reference will
be made to those sections.
To aid in the establishment of test procedures,
the following recommendations are offered. It is
important to recognize that these
recommendations may not apply to all variations
of materials and that modifications may be
required in performing a practical abrasion test.
They should not be construed as fixed test
specifications.
Analyzing the Test Problem
– The value of the
Taber Abraser in research and control programs
depends to a considerable extent on the
operator’s knowledge of the test problem; the
service requirements and the desired wear
characteristics of the material examined.
Analyzing this problem before embarking on a
test series may save time and material. As
nearly as possible, the test should reproduce the
wear experience of the specimen in actual use.
The Test Environment
– An environmentally
controlled test room is strongly recommended
where reproducible precision results are
required. Both heat and moisture affect the
abrasion resistance of most materials,
particularly organic materials. Abrasion
research projects are usually carried out in an
atmosphere maintained at 21 - 24°C
(70 – 75°F)
temperature and 50 percent relative humidity.
Without exception, samples to be tested should
be conditioned in the test atmosphere for at
least 24 hours – organic materials preferably for
48 hours or more. When research is conducted
to determine wear life under changing
atmospheric conditions, as in automobile and
aircraft materials, the atmosphere of the
laboratory is controlled accordingly.
NOTE:
If an environmentally controlled test
laboratory is not available, test specimens should be
conditioned and tested with a minimum lapse of time.
U
WARNING:
When it is necessary to interrupt a
test of organic material for several hours, or
overnight, the sample should be discarded and a
new test begun. In the course of a few hours the
weight of a sample may change by moisture