ASTM D411-98(2003)
(Test Method)Standard Test Methods for Shellac Used for Electrical Insulation
Standard Test Methods for Shellac Used for Electrical Insulation
SIGNIFICANCE AND USE
Polymerization time provides a measure of time during which shellac retains its plasticity and flow properties at the specified temperature before gelling or polymerizing to the tough rubbery insoluble form. This test is important in determining the quality of different lots, useful shelf-life, batch uniformity, and processing characteristics of shellac.
SCOPE
1.1 These test methods cover tests for shellac in the dry button or powder form to be used for electrical insulating purposes. Typically, shellac is used as a bonding agent for mica splittings and reconstituted mica paper products, or as a coating or adhesive for other material.
1.2 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.
Note 1—There is no similar or equivalent IEC standard.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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An American National Standard
Designation:D411–98 (Reapproved 2003)
Standard Test Methods for
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Shellac Used for Electrical Insulation
This standard is issued under the fixed designation D 411; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4.3 Insoluble Matter,
4.4 Iodine Number,
1.1 These test methods cover tests for shellac in the dry
4.5 Moisture Content,
button or powder form to be used for electrical insulating
4.6 Wax,
purposes.Typically,shellacisusedasabondingagentformica
4.7 Ash, and
splittingsandreconstitutedmicapaperproducts,orasacoating
4.8 Orpiment (Native arsenic trisulfide).
or adhesive for other material.
1.2 This standard does not purport to address all of the
POLYMERIZATION TIME
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety and health practices and determine the applica-
5.1 Polymerization time provides a measure of time during
bility of regulatory limitations prior to use.
which shellac retains its plasticity and flow properties at the
NOTE 1—There is no similar or equivalent IEC standard. specified temperature before gelling or polymerizing to the
tough rubbery insoluble form. This test is important in deter-
2. Referenced Documents
mining the quality of different lots, useful shelf-life, batch
2
2.1 ASTM Standards: uniformity, and processing characteristics of shellac.
D 29 Test Methods for Sampling and Testing Lac Resins
6. Apparatus
D 1711 Terminology Relating to Electrical Insulation
D 5032 Practice for Maintaining Constant Relative Humid- 6.1 Test Tubes and Wire Rack—Two 18-mm outside diam-
ity by Means of Aqueous Glycerine Solutions eter glass test tubes, supported by a wire rack to a depth of 100
D 6054 Practice for Conditioning Electrical Insulating Ma- mm when placed in an oil bath. The test tubes must be
terials for Testing supported and maintained in a vertical position. The rack shall
E 104 Practice for Maintaining Constant Relative Humidity be constructed so as to permit free circulation of oil around the
by Means of Aqueous Solutions test tubes.
6.2 Oil Bath—The oil bath shall be constructed with heat-
3. Terminology
ers, temperature control, and means of circulation to maintain
3.1 Definitions: For definitions of terms used in this stan-
the oil or other liquid at a temperature of 150 6 1°C at all
dard, refer to Terminology D 1711. points within the bath. The oil or other liquid used shall be
appropriate for the design of the bath and for safety at the test
4. General Tests
temperature.Thebathshallbeequippedwithathermometer,or
4.1 Each of the following tests shall be made in accordance
other indicator or recorder, to indicate the oil temperature
with the procedures described in Test Methods D 29:
within 61°C.
4.2 Sampling,
6.3 Glass Rod—Asmoothglassrodabout3mmindiameter
and approximately 200 mm long. The end of the glass rod
which is to be immersed in the shellac shall be fire polished to
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These methods are under the jurisdiction of ASTM Committee D09 on
a smooth round end.
Electrical and Electronic Insulating Materials and are the direct responsibility of
Subcommittee D09.01 on Electrical Insulating Varnishes, Powders, and Encapsu-
NOTE 2—A smooth glass rod about 5 mm in diameter and approxi-
lating Compounds.
mately 200 mm long with an indicator mark at the top to indicate
Current edition approved Nov. 10, 1998. Published January 1999. Originally
movement may be used. Flatten slightly the diameter of the glass rod for
approved in 1935. Last previous edition approved in 1998 as D 411 – 98.
2 approximately 3 mm length at the end which is immersed in the shellac.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
The purpose of the flattened rod is to provide a more positive feel of the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
twist back and rubbery character at the end point. If this alternative is
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. used, it must be specified in the report.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D411–98 (2003)
6.4 Timer, for indicating elapsed time in minutes and 12.2 This test method has no bias, because the test values
seconds. are defined solely in terms of this method.
7. Test Specimens
FLOW TEST
7.1 For each test specimen use 4.00 6 0.01 g of shellac,
13. Summary of Test Method
...
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