Significance and Use
The electrical properties of resin-coated glass fabrics are affected by their temperature and moisture content. For this reason it is necessary to control these properties for a specified time immediately prior to testing in order to attain reasonably good reproducibility of test values. The time of exposure to the conditioning atmosphere must be long enough to permit the test specimen to reach a relatively stable value. Usually the moisture content of these materials has little effect on the mechanical properties.
Scope
1.1 These test methods cover procedures for the testing of resin-coated glass fabrics and glass fabric tapes (Note 1) to be used as electrical insulation.
Note 1—Methods of testing varnished cloths and tapes are given in Methods D295.
1.2 The warp threads in fabrics are the threads that are parallel with the length dimension as manufactured.
1.3 The procedures appear as follows:
Procedure
Section ASTM Test
Method Reference
Breaking Strength 22-28 D828
Conditioning 6-8 …
Dielectric Breakdown Voltage and Di-
electric Strength 29-38 D149, D295
Dissipation Factor and Relative Permit-
tivity 52-60 D150, E104, D5032
Effect of Elevated Temperature 39-45 D1830
Resistance to Oil 46-51 D3487
Sampling 3-5 …
Thermal Endurance 68 D1830
Thickness 16-21 D374
Thread Count 12-15 …
Weight 9-11 …
Weight Loss at Elevated Temperature 61-67 D5423
1.4 The values stated in inch-pound units are to be regarded as the standard. The values in parentheses are for information only.
1.5 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. Specific warning statement are given in 35.1.1 and 58.1.