ASTM D7812-16

5.1 The levels of tensile properties obtained when testing aramid paper are dependent on the age and history of the specimen and on the specific conditions used during the test. Among these conditions are rate of stretching, type of clamps, gauge length of specimen, temperature and humidity of the atmosphere, rate of airflow across the specimen, and temperature and moisture content of the specimen. Testing conditions accordingly are specified precisely to obtain reproducible test results on a specific sample.

5.2 Tensile strength is used in engineering calculations when designing various types of products.

5.3 Elongation of the paper is taken into consideration in the design and engineering of reinforced products because of its effect on uniformity of the finished product and its dimensional stability during service.

5.4 Stiffness is a measure of the resistance of the paper to extension as a force is applied.

5.5 Tensile Energy Absorption is dependent on the relationship of force to elongation. It is a measure of the ability of a textile structure to absorb mechanical energy. Tensile Energy Absorption is work-to-break per area.

5.6 It should be emphasized that, although the preceding parameters are related to the performance of the product, the actual configuration of the product is significant. Shape, size, and internal construction also can have appreciable effects on product performance. It is not possible, therefore, to evaluate the performance of the end product in terms of the reinforcing material alone.

5.7 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, test samples should be used that are as homogeneous as possible, that are drawn from the material from which the disparate test results were obtained, and that are randomly assigned in equal numbers to each laboratory for testing. Other materials with established test values may be used for this purpose. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results must be adjusted in consideration of the known bias.

1.1 This test method covers the tensile testing of aramid paper with thickness less than 1 mm. This test method includes testing procedures only and includes no specifications or tolerances.

1.2 The procedures given in this test method are for use with computer-controlled constant-rate-of-elongation tensile testing equipment.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.