ASTM D2370-16(R2021) pdf free download

ASTM D2370-16(R2021) pdf free download.Standard Test Method for Tensile Properties of Organic Coatings
6. Apparatus
6.1 Equipment for applying films of uniform thickness as described in Practices D823. 6.2 Micrometer Film Thickness Gage as described in Test Method D1005. 6.3 Tensile Tester ofthe constant rate ofjaw separation type, equipped with load cells having capacities of 1 to 50 N (0.2 to 10 lb), and equipped with computer with tester controlling software, or optionally an indicating device such as an elec- tronic constant speed chart recorder, a digital device that displays numerical values, or a printer that records the numeri- cal values. Tensile tester can also be equipped with a video- extensometer and environmental chamber, when higher accu- racy of test is required and testing is conducted at an elevated or low temperature. 6.4 Precision Specimen Cutter having a double blade with a foot to hold the sample in place 5 or other suitable sharp cutter blade.
10. Procedure
10.1 Select a mutually agreed upon gage length in the range of 25 to 125 mm (1 to 5 in.). 10.2 Prepare ten test specimens for each material to be evaluated. These specimens should not exhibit any nicks or flaws and should be inspected under 10× magnification for the presence of potential defects. Measure the thickness of each specimen to 60.1 µm (0.04 mil) with a micrometer in accordance with Test Method D1005, taking five measure- ments within the gage length area. If a video-extensometer is used, apply markings on the sample within the distance ofgage length selected. The markings on the sample must be readable by the instrument being used. These will vary between manu- facturer and models. The material and method of making the marks must not affect the characteristics of the sample. 10.3 Set the jaw separation of the tensile tester at the gage length selected. Place the test specimen in the grips of the testing machine, taking care to align the long axis of the specimen with an imaginary line joining the points of attach- ment of the grips to the machine. Tighten the grips evenly and firmly to the degree necessary to minimize slipping of the specimen during test. N OTE 1—Mounting is facilitated by the use of air activated jaws. Line-type jaws will minimize slippage and breakage. The application of pressure-sensitive cloth to the ends of the film can improve jaw grip. Special self-tightening grips designed to be used with thin films could also be used. 10.4 Select a mutually agreed upon rate ofelongation (strain rate) that is in the range of 5 to 100 % ⁄min. Set the crosshead speed of the tensile tester to provide this rate for the gage length chosen. N OTE 2—A rate of elongation should be selected that is optimum for testing the types of materials to be evaluated. For relatively brittle films, elongation rates of5 to 20 % are suggested. For relatively extensible films, elongation rates of 50 to 100 % are suggested. (Refer to Test Method D882 for relation of elongation rate to elongation at break.10.5 Elongate the test specimen until rupture of the film occurs and evaluate the stress-strain curve as follows: 10.5.1 Determine the specimen elongation from video- extensometer data or by measuring the increase in jaw sepa- ration from the point oforiginal load application to the point of rupture. 10.5.2 Measure the tensile pull in Newtons (lb) required to rupture the film. 10.5.3 If stiffness is desired, determine the tensile stress in MPa to elongate the film 1 % from the first point in the stress-strain curve where the slope becomes constant or allow the computer to calculate the appropriate tensile modulus. 10.6 Using the procedures in 10.1 – 10.5, run ten test specimens for each material under test.