ASTM D3377-04

Standard Test Method for Weight Loss of Solventless Varnishes

SCOPE
1.1 This test method covers the determination of the percent weight loss of cured solventless electrical varnishes when exposed to elevated temperatures for prescribed periods of time.
1.2 Results of this test method are based on 6-mm (1/4-in.) thick specimens and will not be applicable to specimens appreciably thinner or thicker than 6 mm.
1.3 The values stated in SI units are to be regarded as the standard.
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—This standard resembles IEC 60216-2 "Guide for the determination of thermal endurance properties of electrical insulating materials. Part 2: Choice of test criteria" in a number of ways, but is not consistently similar throughout. The data obtained using either standard will possibly be technically equivalent.

General Information

• Status: Historical
• Publication Date: 31-Aug-2004
• ICS: 29.035.60 - Varnished fabrics
• Technical Committee: D09 - Electrical and Electronic Insulating Materials
• Drafting Committee: D09.01 - Electrical Insulating Products

Relations

• Replaces: ASTM D3377-00 - Standard Test Method for Weight Loss of Solventless Varnishes
• Effective Date: 01-Sep-2004
• Replaced By: ASTM D3377-04(2009) - Standard Test Method for Weight Loss of Solventless Varnishes
• Effective Date: 01-Oct-2009

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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.
AnAmerican National Standard
Designation:D3377–04
Standard Test Method for
1
Weight Loss of Solventless Varnishes
This standard is issued under the fixed designation D3377; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope ance properties of electrical insulating materials. Part 2:
3
Choice of test criteria
1.1 This test method covers the determination of the percent
weight loss of cured solventless electrical varnishes when
3. Terminology
exposed to elevated temperatures for prescribed periods of
3.1 Definitions:
time.
3.1.1 varnish, n—electrical insulating, a liquid resin system
1
1.2 Results of this test method are based on 6-mm ( ⁄4-in.)
that is applied to and cured on electrical components providing
thick specimens and will not be applicable to specimens
electrical, mechanical, and environmental protection.
appreciably thinner or thicker than 6 mm.
3.1.1.1 Discussion—There are two types of electrical insu-
1.3 The values stated in SI units are to be regarded as the
lating varnish: solvent-containing and solventless.The solvent-
standard.
containing varnish is a solution, dispersion, or emulsion of a
1.4 This standard does not purport to address all of the
polymer or mixture of polymers in a volatile, nonreactable
safety concerns, if any, associated with its use. It is the
liquid. The solventless type is a liquid resin system free of
responsibility of the user of this standard to establish appro-
volatile, nonreactable solvents.
priate safety and health practices and determine the applica-
3.1.2 For definitions of other terms relating to electrical
bility of regulatory limitations prior to use.
insulation, see Terminology D1711.
NOTE 1—This standard resembles IEC 60216–2 “Guide for the deter-
mination of thermal endurance properties of electrical insulating materi-
4. Significance and Use
als. Part 2: Choice of test criteria” in a number of ways, but is not
4.1 The amount and composition of by-products produced
consistently similar throughout. The data obtained using either standard
by exposure of insulating varnishes to elevated temperatures
will possibly be technically equivalent.
can possibly:
2. Referenced Documents
4.1.1 Deteriorate other insulations in the system,
2
4.1.2 Cause cracking of insulation due to pressure, buildup
2.1 ASTM Standards:
in thick cross sections, or
D1711 Terminology Relating to Electrical Insulation
4.1.3 Corrode other parts in the assembly.
D5423 Specification for Forced-Convection Laboratory
4.2 Amount and rate of weight loss will possibly affect the
Ovens for Evaluation of Electrical Insulation
thermal rating of a varnish.
2.2 IEC Standard:
IEC 60216–2 Guide for the determination of thermal endur-
5. Apparatus
5.1 Metal Mold, consisting of two flat sheets 300 by 300 by
1 1
1
6 mm (12 by 12 by ⁄4 in.) separated by 6.4 6 0.5-mm ( ⁄4 6
This test method is under the jurisdiction of ASTM Committee D09 on
Electrical and Electronic Insulating Materials and is direct responsibility of
0.02-in.) thick spacers along three sides. The spacers also seal
Subcommittee D09.01 on Electrical Insulating Varnishes, Powders, and Encapsu-
the edges of the mold and the assembly is held together with
lating Compounds.
“C” clamps or bolts. Aluminum or polished steel plates are
Current edition approved Sept. 1, 2004. Published September 2004. Originally
approved in 1975. Last previous edition approved in 2000 as D3377 – 00. DOI: permissible.
10.1520/D3377-04.
5.2 Laboratory Balance, with accuracy of 6 1 mg.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute, 11 W. 42nd St., 13th
the ASTM website. Floor, New York, NY 10036.
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D3377–04
5.3 Forced-Convection Laboratory Oven, meeting require-
155 175 to 225
180 200 to 250
ments of Specification D5423, Type II for each test tempera-
200 220 to 275
ture.
220 250 to 300
1
5.4 Screening Platform, 6-mm ( ⁄4-in.) mesh, with 50-mm
Choose three temperatures within the above ranges at least
(2-in.) legs.
20 °C apart.
5.5 Mold Release.
6.14 Exposure Times:
NOTE 2—Fluorocarbon-type release agents are satisfactory.
Hours—24 48 72 96 168
5.6 Desiccator.
NOTE 4—If desired, longer exposure times are permitted.
6.15 After each test period, remove the specime
...