ASTM D3394-16(2022)

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.
Designation: D3394 − 16 (Reapproved 2022)
Standard Test Methods for
Sampling and Testing Electrical Insulating Board
This standard is issued under the fixed designation D3394; 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 establish appropriate safety, health, and environmental prac-
tices and determine the applicability of regulatory limitations
1.1 These test methods cover the sampling and testing of
prior to use.
electrical insulating boards. These boards are porous, usually
1.7 This international standard was developed in accor-
fibrous sheets used for dielectric and structural purposes in
dance with internationally recognized principles on standard-
electrical apparatus.
ization established in the Decision on Principles for the
1.2 These test methods are not intended for testing vulca-
Development of International Standards, Guides and Recom-
nized fibre or molded laminated sheets.
mendations issued by the World Trade Organization Technical
1.3 These test methods are applicable to board materials Barriers to Trade (TBT) Committee.
having a nominal thickness of at least 0.030 in. (0.76 mm).
2. Referenced Documents
NOTE 1—For materials thinner than 0.030 in. (0.76 mm) see Test
2.1 ASTM Standards:
Methods D202.
D149 Test Method for Dielectric Breakdown Voltage and
1.4 The test methods appear in the following sections:
DielectricStrengthofSolidElectricalInsulatingMaterials
ASTM Method
at Commercial Power Frequencies
Sections Reference
D202 Test Methods for Sampling and Testing Untreated
Apparent Density 18–23
Aqueous Extract Characteristics 36 – 42 D202
Paper Used for Electrical Insulation
Ash Content 43–46 T 413
D374 Test Methods for Thickness of Solid Electrical Insu-
Compatibility with Dielectric 47 – 52 D664, D877, D924,
lation (Metric) D0374_D0374M
Liquids D971, D974, D1169,
D1500, D1816,
D586 Test Method for Ash and Organic Matter Content of
D3455, D3487
Degradable Erosion Control Products
Compressibility 79–85
D644 Test Method for Moisture Content of Paper and
Conditioning 11 D685
Degree of Polymerization 86 – 89 D4243
Paperboard by Oven Drying (Withdrawn 2010)
Dielectric Strength in Air 53 – 59 D149
D664 Test Method for Acid Number of Petroleum Products
Dielectric Strength in Oil 60 – 65 D149, D2413, D3426
by Potentiometric Titration
Dimensions of Sheets 12–17
Moisture Content 31 – 35 D644
D685 Practice for Conditioning Paper and Paper Products
Oil Absorption 72–78
for Testing
Reports 10
D877 Test Method for Dielectric Breakdown Voltage of
Sampling 6 – 9 D3636
Shrinkage 24 – 30 D644
Insulating Liquids Using Disk Electrodes
Tensile Properties 66 – 71 D202
D924 Test Method for Dissipation Factor (or Power Factor)
1.5 The values stated in inch-pound units are to be regarded
and Relative Permittivity (Dielectric Constant) of Electri-
as standard. The values given in parentheses are mathematical
cal Insulating Liquids
conversions to SI units that are provided for information only
D971 Test Method for Interfacial Tension of Insulating
and are not considered standard.
Liquids Against Water by the Ring Method
1.6 This standard does not purport to address all of the D974 Test Method for Acid and Base Number by Color-
Indicator Titration
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to consult and D1169 Test Method for Specific Resistance (Resistivity) of
Electrical Insulating Liquids
1 2
These test methods are under the jurisdiction of ASTM Committee D09 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Electrical and Electronic Insulating Materials and are the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D09.01 on Electrical Insulating Products. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved May 1, 2022. Published May 2022. Originally the ASTM website.
approved in 1975. Last previous edition approved in 2016 as D3394 – 16. DOI: The last approved version of this historical standard is referenced on
10.1520/D3394-16R22. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3394 − 16 (2022)
D1500 Test Method forASTM Color of Petroleum Products 7. Terminology
(ASTM Color Scale)
7.1 Definitions of Terms Specific to This Standard:
D1816 Test Method for Dielectric Breakdown Voltage of
7.1.1 The descriptions of terms used in this test method,
Insulating Liquids Using VDE Electrodes
with the exception of the definition of “unit of product,” are in
D2413 Practice for Preparation of Insulating Paper and
accordance with Practice D3636.
Board Impregnated with a Liquid Dielectric
7.1.2 unit of product, n—an entity of electrical insulating
D2865 Practice for Calibration of Standards and Equipment
board on which one or more quality characteristics is deter-
for Electrical Insulating Materials Testing
mined. A unit of product is a sheet, pallet, box, carton, case,
D3426 Test Method for Dielectric Breakdown Voltage and
package, or bundle. The unit of product is established by the
DielectricStrengthofSolidElectricalInsulatingMaterials
customer and is or is not the same as the unit of purchase,
Using Impulse Waves
supply, production, or shipment.
D3455 Test Methods for Compatibility of Construction Ma-
terial with Electrical Insulating Oil of Petroleum Origin 8. Establishing Acceptable Quality Levels (AQLs)
D3487 Specification for Mineral Insulating Oil Used in
8.1 Acceptable quality levels (AQLs) for each major and
Electrical Apparatus
minor property (as defined in Practice D3636) shall be as
D3636 Practice for Sampling and Judging Quality of Solid
mutually agreed upon between the purchaser and the seller. In
Electrical Insulating Materials
addition, if group AQLs are established for given groups of
D4243 Test Method for Measurement ofAverage Viscomet-
propertiesandthesetooshallbemutuallyagreeduponbetween
ric Degree of Polymerization of New andAged Electrical
the purchaser and the seller.
Papers and Boards
E29 Practice for Using Significant Digits in Test Data to 9. Selection of Sample and Identification of Lot Sample
Determine Conformance with Specifications
9.1 Samples shall be in accordance with Practice D3636,
2.2 TAPPI Standard:
with the exception of those paragraphs pertaining specifically
T 413 Determination of Ash in Paper
to rolls, pads, or bobbins.
9.2 Mark each unit of the sample so that it is identifiable at
3. Terminology
any time by the seller and the purchaser.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 electrical insulating board, n—a sheet structure, usu-
REPORTS
ally composed of cellulosic fibers, utilized for dielectric or
10. Report
structural purposes or both in a variety of electrical apparatus.
Board is herein arbitrarily differentiated from paper in that it is
10.1 At the completion of all tests record the results in a test
at least 0.030 in. (0.76 mm) thick and is manufactured only in
report that includes the following:
sheets of limited length. Other names for these products are
10.1.1 Identification (of the board sampled and tested) by
pressboard, transformer board, fuller board, and press pan.
lot number, type, grade, and so forth),
10.1.2 Dates of testing,
4. Summary of Test Methods
10.1.3 Locationofthetestinglaboratoryandthenameofthe
4.1 This standard is a compilation of test methods for
person responsible for testing,
electrical insulating board. Provisions are included for
10.1.4 Remarks indicating the method used and any devia-
sampling, testing, and judging acceptability of a given quantity tion from the standard,
of board.
10.1.5 Testresultsasspecifiedintheindividualmethod,and
10.1.6 Specification limits for each property measured for
5. Reagents
the board being tested.
5.1 Reagents shall conform to the requirements set forth in
10.2 Report the results as calculated or observed values
Test Methods D202.
rounded to the nearest unit in the last right-hand place of
figures used in the material specification to express the limiting
SAMPLING
value (see Practice E29).
6. Scope
CONDITIONING
6.1 This test method covers the determination of lot accept-
11. Conditioning
ability of electrical insulating board. It is designed for the
purpose of determining acceptability of all or that portion of a
11.1 Conditionsamplesandspecimenscutfromthesamples
shipment to a customer identified by a manufacturer’s lot
(with the exception of samples taken for moisture determina-
number. It is not intended to cover internal board mill quality
tion or as otherwise specified) in a circulating-air atmosphere
control plans. The method is intended for use in conjunction
maintained at 50 % 6 2 % relative humidity and a temperature
with product specifications for electrical insulating board.
of 23 °C 6 2 °C, using procedures as specified in Practice
D685.
11.2 For referee purposes, the conditioning specified in 11.1
Available from TechnicalAssociation of the Pulp and Paper Industry (TAPPI),
15 Technology Parkway South, Norcross, GA 30092, http://www.tappi.org. will give most consistent results. However, for routine testing
D3394 − 16 (2022)
under factory or other non-standard atmospheric conditions, if 16.1.4 Variation in thickness, reported as the difference
the board has a moisture content within the range from 5 % to between the highest and the lowest thickness value obtained in
7 % as determined in Sections31–34, there will be only slight 15.3.
variations from properties as determined after conditioning
17. Precision and Bias
specified above.
17.1 The precision and bias of this test method are not
DIMENSIONS OF SHEETS
known.
APPARENT DENSITY
12. Apparatus
12.1 Scale—A scale of suitable length graduated such that
18. Scope
lengths, widths, and diagonals can be directly read to within
18.1 This test method is used for determination of apparent
half of the allowable tolerance for these dimensions. The scale
density of insulating board, using measurements of dimensions
shallbeproperlycalibratedinaccordancewithPracticeD2865.
and weight made after appropriate conditioning.
12.2 Thickness-Measuring Device—Machinist micrometer
18.2 Procedures are given for determining either the “wet-
with ratchet as specified in Test Methods D374.
wet” or the “dry-dry” density.
13. Sampling 19. Significance and Use
13.1 Sample in accordance with Sections6–9. 19.1 Apparent density affects the dielectric and physical
characteristics of insulating board and is a factor in the
14. Test Specimens economics of its use in apparatus. This test is useful for
specification, design, and quality control purposes.
14.1 Specimens for determination of length, width, and
squareness of sheets shall be whole sheets. For thickness
20. Apparatus
determinations, use a whole sheet or, if desired, a portion of a
20.1 ScaleorCalipers,graduatedinunitsoflength,withthe
whole sheet will serve as a specimen. If a portion is selected as
smallest graduation equal to, or less than, 0.25 % of the
a specimen for thickness determination, that portion shall be
smallest dimension to be measured, calibrated in accordance
representative of the full width (cross-grain direction) of the
with Practice D2865.
sheet.
20.2 Balance, graduated in units of weight, with the small-
14.2 Determine the dimensions as received, provided the
est graduation equal to, or less than, 0.25 % of the specimen
moisture content is in the specification range for the material
weight, calibrated in accordance with Recommended Practice
being tested (see 11.2).
D2865.
20.3 Thickness-Measuring Device, conforming to the re-
15. Procedure
quirements of Test Methods D374, Method A.
15.1 Measure the length and the width of each specimen to
20.4 Oven, conforming to the requirements of Test Method
the nearest appropriate unit. Make at least two measurements
in each direction. D644.
15.2 Measure each of the two diagonals of each specimen.
21. Procedure
15.3 Measure the thickness in accordance with Test Meth-
21.1 From each unit of product in the sample obtained in
ods D374, Method A. Make at least five thickness determina-
accordance with Sections 6 through 9, prepare at least two
tions across the sheet.
rectangular specimens having an area of at least 75 in. (0.05
m ) each.
NOTE 2—Points of measurement are selected to include the areas most
likely to be the extremes.
21.2 Procedure A: Wet-Wet Density—Condition the speci-
mens in accordance with Section 11.
16. Report
21.3 Procedure B: Dry-Dry Density—Dry the specimens to
16.1 The report shall conform to Section 10 and shall
constant weight in an oven at 105 °C 6 3 °C, in accordance
include the following:
with Test Method D644. Cool to room temperature, using a
16.1.1 Sheet size, reported as the average of the measure-
desiccator or other means to prevent reabsorption of moisture.
ments in each direction.
Exposure to the open air while making the measurements
16.1.2 Squareness of the sheet, reported as the quotient of
specified in 21.4 shall be sufficiently brief that there will not be
the shorter diagonal divided by the longer diagonal (for
aweightincreaseofmorethan0.1 %oftheoven-dryweightof
convenience, squareness is expressed as a percent).
the specimens.
NOTE 3—This method of calculating squareness assumes that the sheet
21.4 Measurethewidth,length,andthicknessinaccordance
closely approximates a parallelogram in shape. If measurements of width
with Section 15 to determine the weight of each specimen.
orlengthvaryatdifferentpoints,itispossiblethatahighsquarenessvalue
is calculated from measurements on a sheet that differs significantly from
21.5 From the dimensions and weight of each specimen,
being rectangular.
calculate the apparent density and report the results in units of
16.1.3 Average thickness, and grams per cubic centimetre, calculated as follows:
D3394 − 16 (2022)
weight 3factor 28. Calculation
Apparent density, g/cm 5 (1)
volume
28.1 From the average dimensions before and after drying
Weight Units Volume Units Factor
in each of the three directions, calculate the linear shrinkage in
gcm 1
3 each of the three directions as a percentage of the respective
gin. 0.0610
lb in. 27.68 initial dimensions.
29. Report
22. Report
29.1 The report shall be in accordance with Section 10, and
22.1 The report shall be in accordance with Section 10, and
shall include the average shrinkage for each specimen in the
include the individual results for the apparent density of each
grain direction, the cross direction, and the thickness.
specimen.
30. Precision and Bias
23. Precision and Bias
30.1 The precision and bias of this test method are not
23.1 The precision and bias of this test method are not
known.
known.
MOISTURE CONTENT
SHRINKAGE
31. Significance and Use
24. Significance and Use
31.1 Moisture content of electrical insulating board is im-
24.1 The dimensions of electrical insulating boards will
portant for economic and technical reasons. Many physical and
change as a function of moisture content, which varies with
dimensional characteristics of board are affected by moisture
changes in the ambient relative humidity or as a result of heat
content and moisture content history. This test is useful for
or vacuum used in drying operations.The suitability of a board
specification and quality control use. (For a more complete
for some particular applications is affected by the magnitude
treatise on the significance of moisture content, see STP 60 B
and direction of these dimensional changes.
Paper and Paperboard—Characteristics, Nomenclature, and
24.2 The dimensional changes resulting from oven drying
Significance of Tests. )
of specimens that have been conditioned under specified
32. Procedure
humidityconditionsareusedinthismethodasameasureofthe
shrinkage characteristics. This method is useful for design 32.1 From a sample obtained in accordance with Sections 6
–9 take carefully protected specimens and determine the
purposes, for specifications, and for some special control
purposes. moisture content in accordance with Test Method D644. Take
specimens from the test units and place immediately in a
25. Test Specimens
moisture-proof container, transport to a laboratory, and weigh
immediately prior to oven drying.
25.1 Cut square or rectangular pieces having dimensions of
at least 3 in. (76 mm) in the plane of the sheet.The dimensions
33. Calculation
intheplaneofthesheetaredeterminedbymeasuringeitherthe
33.1 Calculate the moisture content of the board as follows:
overall distances between smoothly finished edges, or the
distances between benchmarks on one face of the specimen.
Moisture content,% (2)
The optimum size of the test specimen will be determined by
5 ~weight loss on drying 3100/original weight!
the method used for measuring the dimensions, and by the size
of the conditioning chamber available.
34. Report
34.1 The report shall be in accordance with Section 10, and
26. Conditioning
shall include the high, low, and average moisture content of the
26.1 Unless otherwise specified, condition the specimens to
lot of board.
equilibrium with a standard atmosphere as specified in Section
11. 35. Precision and Bias
35.1 The precision and bias of this test method are not
27. Procedure
known.
27.1 Measure the dimensions of the specimens in the grain
direction, the cross direction, and the thickness, in accordance AQUEOUS EXTRACT CHARACTERISTICS
with Sections12–16. Make the measurements in the atmo-
36. Summary of Test Method
sphere in which conditioning was performed, or within 3 min
36.1 Procedures are specified for the preparation of aqueous
of removal from that atmosphere.
extracts and for determination of their characteristics, includ-
27.2 Dry the specimens to constant weight at 105 °C, and
ing conductivity, pH, free acidity and alkalinity, and soluble
cool to room temperature in accordance with Test Method
chloride content.
D644.
27.3 Measure the dimensions of the specimens in accor-
Available from ASTM Headquarters, 100 Barr Harbor Drive, PO Box C700,
dance with 27.1. West Conshohocken, PA 19428–2959.
D3394 − 16 (2022)
37. Significance and Use 43.3 This method is suitable for control testing, research,
and specification purposes.
37.1 It is possible that water-soluble extractives, such as
ionizable acids, bases, salts, or combinations thereof will
44. Procedure
degrade insulating qualities of board. It is possible excessive
44.1 Take test specimens from samples gathered in accor-
quantities will lower the insulation resistance and cause corro-
dance with Sections 6 to 9. Test two specimens from each test
sion or degradation of the board under electric stress. Many of
unit.
these impurities can be detected and their amounts estimated
44.2 Determine the ash content in accordance with TAPPI
from measurements of conductivity, pH, free acidity or
alkalinity, and chloride content of aqueous extracts of the Method T 413, except use 575 °C 6 25 °C for the ashing
temperature.
board.
38. Apparatus
45. Report
38.1 The apparatus shall be as specified in Test Methods 45.1 The report shall be in accordance with Section 10, and
D202 for the corresponding tests.
with the Report Section of Test Method D586.
39. Test Specimens
46. Precision and Bias
39.1 In preparing specimens for the tests in 40.1 – 40.3, cut
46.1 For the precision and bias of this method see TAPPI
the board into pieces as small as possible, consistent with
T 413.
minimal handling and exposure. In the case of specimens from
COMPATIBILITY WITH DIELECTRIC LIQUIDS
thick, high-density boards, extend the maceration time to 10
min if needed to pulp the specimen completely.
47. Scope
40. Procedure
47.1 This test method detects the presence of extractable
contaminating substances in electrical insulating board by the
40.1 Acidity-Alkalinity-pH—Test in accordance with Test
measurement of changes in selected properties of a liquid after
Methods D202.
contact with the board under specified condition.
40.2 Conductivity—Test in accordance with Test Methods
47.2 This method also provides for measurement of the
D202.
effect of the liquid on the board by observation of changes in
40.3 Chloride Content—Test in accordance with Method A
board properties after exposure to the liquid under specified
of Test Methods D202, except before refluxing, macerate the
conditions.
specimen for 5 min, using the same apparatus and procedure
used to prepare aqueous extracts for pH measurements (40.1).
48. Significance and Use
48.1 Liquid-filled electrical apparatus uses refined mineral
41. Report
oil or other liquids which are adversely affected by contami-
41.1 The report shall be in accordance with Section 10 and
nants in boards. This method is useful for determining the
shall include the following:
effect of liquids upon board properties and the effect of board
41.1.1 Test procedure used, and
contaminants upon liquid properties. The method is useful for
41.1.2 Results of each test, including results of tests on
comparison of materials, for routine control, and for specifi-
blanks.
cation purposes.
42. Precision and Bias
48.2 It is not intended that this method be used as a measure
42.1 The precision and bias of the test for acidity-alkalinity- of the thermal capability of the board, the liquid, or the
pH, and of conductivity are not known. combination thereof. The specified time and temperature are
selected so that the test is a measure of the soluble contami-
42.2 For
...