ASTM D352-97(2003)

Standard Test Methods for Pasted Mica Used in Electrical Insulation

SIGNIFICANCE AND USE
This test determines the compressive creep under laboratory conditions or under conditions that may be encountered during manufacture of electrical equipment. It has special significance if the material to be tested is applied as commutator segment insulation. It serves as a measure under specified conditions of the ability of the material to resist deformation while under compressive load, during exposure to elevated temperature for a specified time. This test is suitable for acceptance tests and for manufacturing control.
SCOPE
1.1 These test methods cover the testing of bonded mica splittings and bonded mica paper to be used for commutator insulation, hot molding, heater plates, and other similar insulating purposes.
1.2 These test methods appear in the following sections:
Test SectionsCompressive Creep4-10 Dielectric Strength38-41 Mica or Binder Content19Molding Test31-36 Organic Binder20-24 Resistivity42-46  Silicone Binder25-.30  Stability Under Heat and Pressure 11-18
1.3 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. See 40.1 and 45.1 for specific hazard statements.
1.4 The values stated in inch-pound units are to be regarded as the standard.

General Information

• Status: Historical
• Publication Date: 09-Mar-2003
• ICS: 29.035.50 - Mica based materials
• Technical Committee: D09 - Electrical and Electronic Insulating Materials

Relations

• Replaces: ASTM D352-97 - Standard Test Methods for Pasted Mica Used in Electrical Insulation
• Effective Date: 10-Mar-2003
• Replaced By: ASTM D352-97(2008)e1 - Standard Test Methods for Pasted Mica Used in Electrical Insulation
• Effective Date: 01-May-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation:D352–97 (Reapproved 2003)
Standard Test Methods for
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Pasted Mica Used in Electrical Insulation
This standard is issued under the fixed designation D352; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.1 binder content, n, (of pasted mica)—the percent by
weight of binder relative to the original weight of a specimen
1.1 These test methods cover the testing of bonded mica
as determined by procedures specified herein.
splittings and bonded mica paper to be used for commutator
3.2.1.1 Discussion—Binder content includes any residual
insulation, hot molding, heater plates, and other similar insu-
solvent.Pastedmicamaterialsnotfullycured(suchasmolding
lating purposes.
and flexible plates) may contain appreciable quantities of
1.2 These test methods appear in the following sections:
solvent in the binder. This solvent is usually later removed
Test Sections
when the material is cured in the manufacture of electrical
Compressive Creep 4-10
equipment. In such cases, the binder content after cure is less
Dielectric Strength 38-41
Mica or Binder Content 19 (by the amount of solvent removed) than would be determined
Molding Test 31-36
by this method. To determine the binder content after cure of
Organic Binder 20-24
materialsthatarenotfullycured,butsubsequentlywillbe,itis
Resistivity 42-46
necessary, before initially weighing the specimen, to heat the
Silicone Binder 25-30
specimenforatimeandatatemperaturethatdependsuponthe
Stability Under Heat and Pressure 11-18
material from which the specimen is prepared.
1.3 This standard does not purport to address all of the
3.2.2 compressive creep, n—the change in thickness of a
safety concerns, if any, associated with its use. It is the
bondedmicaceousmaterialresultingfromexposuretoelevated
responsibility of the user of this standard to establish appro-
temperature for a specified time while a specimen is under a
priate safety and health practices and determine the applica-
specified compressive load.
bility of regulatory limitations prior to use. See 40.1 and 45.1
3.2.3 mica content, n, (of pasted mica)—the percent by
for specific hazard statements.
weight of mica relative to the original weight equal to 100%
1.4 The values stated in inch-pound units are to be regarded
minusthebindercontentasdeterminedbyproceduresspecified
as the standard.
herein.
2. Referenced Documents
COMPRESSIVE CREEP
2.1 ASTM Standards:
4. Significance and Use
D149 Test Method for Dielectric Breakdown Voltage and
Dielectric Strength of Solid Electrical Insulating Materials 4.1 This test determines the compressive creep under labo-
2
at Commercial Power Frequencies ratory conditions or under conditions that may be encountered
D257 Test Methods for DC Resistance or Conductance of during manufacture of electrical equipment. It has special
2
Insulating Materials significance if the material to be tested is applied as commu-
2
D1711 Terminology Relating to Electrical Insulation tatorsegmentinsulation.Itservesasameasureunderspecified
conditions of the ability of the material to resist deformation
3. Terminology
while under compressive load, during exposure to elevated
3.1 Definitions: temperature for a specified time. This test is suitable for
3.1.1 For definitions of terms relating to electrical insula-
acceptance tests and for manufacturing control.
tion, refer to Terminology D1711.
5. Apparatus
3.2 Definitions of Terms Specific to This Standard:
5.1 Hydraulic Press—Ahydraulicpresshavingtemperature
controlled, electrically heated platens, or a press with other
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These test methods are under the jurisdiction of ASTM Committee D09 on
provisions for heating the specimen and controlling the tem-
Electrical and Electronic Insulating Materials and are the direct responsibility of
perature. The platens shall be at least 4 by 4 in. (102 by 102
Subcommittee D09.19 on Dielectric Sheet and Roll Products.
Current edition approved March 10, 2003. Published April 2003. Originally
mm) in size. The press shall be capable of exerting a force of
approved in 1932. Last previous edition approved in 1997 as D352–97.
at least 4000 lb (18 kN). The apparatus shall be capable of
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Annual Book of ASTM Standards,Vol 10.01.
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D352–97 (2003)
be allowed to circulate in ducts provided in the platens. The rate of water
maintaining a specimen temperature of at least 200 6 5°C. It
flow, if used, should be adjusted to give a co
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