Significance and Use
7.1 Accurate determination of thickness is important for identification purposes. Thickness is related to weight and must be known in order to calculate apparent density and the dielectric strength.
7.2 Thickness variation affects the quality of roll winding and is useful in judging the uniformity of mica paper particularly with respect to dielectric breakdown voltage, impregnation time, and thickness of the end product.
Scope
1.1 These methods cover procedures for sampling and testing untreated mica paper to be used as an electrical insulator or as a constituent of a composite material used for electrical insulating purposes.
1.2 The procedures2 appear in the following order:
ASTM
Method
Procedures
Sections
References
Apparent Density
12
…
Aqueous Extract Conductivity
32 and 33
D202
Conditioning
4
D685
Dielectric Strength
16 – 19
D149
Impregnation Time
20 – 24
D202
Moisture Content
26 – 28
D644
Roll Quality
25
…
Sampling
3
…
Tensile Strength
13 – 15
D828
Thickness
6 – 10
D374
Weight
11
D646
Weight Variability
29 – 31
…
1.3 The values stated in inch-pound units are to be regarded as the 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
