ASTM D619-21

Standard Test Methods for Vulcanized Fibre Used for Electrical Insulation

ABSTRACT
These test methods details the standard procedures for testing certain properties of vulcanized fibre sheets, tubes, and rods of such grades as can be used for electrical insulation. Arc resistance, ash content, bond strength (ply adhesion), bursting strength, compressive strength, conditioning, density, dielectric strength, dimensional measurements, flammability, flexural strength, silica content, tearing strength, tensile strength, thickness (for sheets), resistance to impact, Rockwell hardness, volatile matter content, water absorption, and zinc chloride content are among the properties that these test methods shall be able to examine.
SCOPE
1.1 These test methods cover the procedures for testing vulcanized fibre sheets, rolls, tubes, and rods of such grades as can be used for electrical insulation.  
1.2 The procedures appear in the following sections:    
Procedure  
Section  
Arc Resistance  
23  
Ash  
6  
Bond Strength (Ply Adhesion)  
16  
Bursting Strength  
14  
Compressive Strength  
12, 25, 30  
Conditioning  
4  
Density  
17, 26, 32  
Dielectric Strength  
18, 27  
Dimensional Measurements  
28, 33  
Flammability  
22  
Flexural Strength  
13, 31  
Silica  
7  
Tearing Strength  
11  
Tensile Strength  
10, 24, 29  
Thickness (Sheets)  
20  
Resistance to Impact  
15  
Rockwell Hardness  
19  
Volatile Matter  
8  
Water Absorption  
5  
Zinc Chloride  
9  
1.3 The values stated in inch-pound units are to be regarded as the standard. The SI values given in parentheses are for information only.  
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. Specific hazard statements are given in 7.3, 22.1, and 22.2.
Note 1: The test methods described herein are similar technically to those described in IEC Publication 60667-2. Not all of the tests in this document are included in IEC 60667-2, and the procedures in the two publications are not completely identical; but it is expected that comparable results will be obtained from most of the procedures. Conduct comparative tests if necessary before directly comparing results of tests using the different procedures.  
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.

General Information

• Status: Published
• Publication Date: 31-Dec-2020
• ICS: 29.035.10 - Paper and board insulating materials
• Technical Committee: D09 - Electrical and Electronic Insulating Materials
• Drafting Committee: D09.07 - Electrical Insulating Materials

Relations

• Refers: ASTM D1711-24 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Mar-2024
• Refers: ASTM D689-17(2024) - Standard Test Method for Internal Tearing Resistance of Paper
• Effective Date: 01-Mar-2024
• Refers: ASTM D149-20 - Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies
• Effective Date: 01-Jan-2020
• Refers: ASTM D710-19 - Standard Specification for Vulcanized Fibre Sheets, Rolls, Rods, and Tubes Used for Electrical Insulation
• Effective Date: 01-Nov-2019
• Refers: ASTM D229-19 - Standard Test Methods for Rigid Sheet and Plate Materials Used for Electrical Insulation
• Effective Date: 01-Mar-2019
• Refers: ASTM D828-16 - Standard Test Method for Tensile Properties of Paper and Paperboard Using Constant-Rate-of-Elongation Apparatus
• Effective Date: 01-Nov-2016
• Refers: ASTM D1711-15 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Nov-2015
• Refers: ASTM D1711-14a - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Nov-2014
• Refers: ASTM D1711-14 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-May-2014
• Refers: ASTM D348-13 - Standard Test Methods for Rigid Tubes Used for Electrical Insulation (Withdrawn 2020)
• Effective Date: 01-Nov-2013
• Refers: ASTM D349-13 - Standard Test Methods for Laminated Round Rods Used for Electrical Insulation (Withdrawn 2020)
• Effective Date: 01-Nov-2013
• Refers: ASTM D710-13 - Standard Specification for Vulcanized Fibre Sheets, Rods, and Tubes Used for Electrical Insulation
• Effective Date: 01-Nov-2013
• Refers: ASTM D1711-13 - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Nov-2013
• Refers: ASTM D668-12 - Standard Test Methods of Measuring Dimensions of Rigid Rods and Tubes Used for Electrical Insulation (Withdrawn 2020)
• Effective Date: 01-Nov-2012
• Refers: ASTM D1711-11a - Standard Terminology Relating to Electrical Insulation
• Effective Date: 01-Aug-2011

Overview

ASTM D619-21: Standard Test Methods for Vulcanized Fibre Used for Electrical Insulation is a comprehensive international standard developed by ASTM International. It establishes standardized procedures for testing vulcanized fibre sheets, rolls, tubes, and rods, focusing on those grades suitable for electrical insulation applications. The standard addresses a wide array of physical, chemical, and electrical test methods, ensuring the consistent evaluation of material quality, safety, and performance in electrical insulation systems.

Key Topics

ASTM D619-21 includes methods for assessing the following critical properties of vulcanized fibre electrical insulation materials:

• Arc resistance – Evaluates the resistance to high-voltage, low-current arc exposure.
• Ash content – Measures inorganic residue, indicating material purity.
• Bond strength (ply adhesion) – Assesses the strength of laminated plies to prevent delamination.
• Bursting strength – Determines resistance to rupture under pressure.
• Compressive strength – Measures material behavior under compressive load.
• Conditioning – Defines sample preparation to ensure reproducible results.
• Density – Evaluates material economics and quality uniformity.
• Dielectric strength – Critical for electrical insulation, measuring resistance to electrical breakdown.
• Dimensional measurements – Verifies conformity to tolerances.
• Flammability – Assesses ignition resistance and burning rate.
• Flexural strength – Measures resistance to bending forces.
• Silica content – Checks process efficiency and material composition.
• Tearing strength – Determines suitability for processing and mechanical reliability.
• Tensile strength – Evaluates the material’s ability to withstand tension.
• Thickness (for sheets) – Essential for electrical and mechanical property calculations.
• Resistance to impact – Measures durability in shock or stress environments.
• Rockwell hardness – Indicates resistance to indentation and processing quality.
• Volatile matter content – Assesses moisture and other volatiles affecting performance.
• Water absorption – Evaluates hydroscopic behavior and effect on insulation capability.
• Zinc chloride content – Monitors manufacturing process quality.

Applications

ASTM D619-21 is widely applied in industries that utilize vulcanized fibre for electrical insulation. Typical real-world applications include:

• Electrical and electronic device manufacturing – Ensuring components such as sheets, tubes, and rods meet stringent insulation standards.
• Quality assurance and incoming inspection – Verifying material conformance for reliable performance in transformers, switchgear, and electric motors.
• Research and development – Providing baseline data for material innovation and comparative analyses.
• Product design and engineering – Supplying essential physical and electrical property data for calculating performance and safety margins.

By following ASTM D619-21, organizations can:

• Guarantee the material's insulation performance and fire safety.
• Maintain process consistency by regularly checking physical and chemical properties.
• Align with international best practices for quality and conformity assessment.

Related Standards

Users of ASTM D619-21 may also reference the following related standards:

• ASTM D710 – Specification for Vulcanized Fibre Sheets, Rolls, Rods, and Tubes Used for Electrical Insulation
• ASTM D149 – Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials
• ASTM D229 – Rigid Sheet and Plate Materials Used for Electrical Insulation
• ASTM D256 – Izod Pendulum Impact Resistance of Plastics
• ASTM D495 – High-Voltage, Low-Current, Dry Arc Resistance of Solid Electrical Insulation
• IEC 60667-2 – Specification for Vulcanized Fibre for Electrical Purposes - Methods of Test

Following ASTM D619-21 helps organizations achieve compliance, quality control, and optimal performance for vulcanized fibre used in electrical insulation systems, supporting both regulatory and operational excellence in manufacturing and product deployment.

Standards Content (Sample)

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: D619 − 21
Standard Test Methods for
Vulcanized Fibre Used for Electrical Insulation
This standard is issued under the fixed designation D619; 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* 1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 These test methods cover the procedures for testing
ization established in the Decision on Principles for the
vulcanized fibre sheets, rolls, tubes, and rods of such grades as
Development of International Standards, Guides and Recom-
can be used for electrical insulation.
mendations issued by the World Trade Organization Technical
1.2 The procedures appear in the following sections:
Barriers to Trade (TBT) Committee.
Procedure Section
Arc Resistance 23
2. Referenced Documents
Ash 6
Bond Strength (Ply Adhesion) 16
2.1 ASTM Standards:
Bursting Strength 14
D149 Test Method for Dielectric Breakdown Voltage and
Compressive Strength 12, 25, 30
Conditioning 4 DielectricStrengthofSolidElectricalInsulatingMaterials
Density 17, 26, 32
at Commercial Power Frequencies
Dielectric Strength 18, 27
D202 Test Methods for Sampling and Testing Untreated
Dimensional Measurements 28, 33
Flammability 22
Paper Used for Electrical Insulation
Flexural Strength 13, 31
D229 Test Methods for Rigid Sheet and Plate Materials
Silica 7
Used for Electrical Insulation
Tearing Strength 11
Tensile Strength 10, 24, 29
D256 Test Methods for Determining the Izod Pendulum
Thickness (Sheets) 20
Impact Resistance of Plastics
Resistance to Impact 15
D348 Test Methods for Rigid Tubes Used for Electrical
Rockwell Hardness 19
Volatile Matter 8
Insulation (Withdrawn 2020)
Water Absorption 5
D349 Test Methods for Laminated Round Rods Used for
Zinc Chloride 9
Electrical Insulation (Withdrawn 2020)
1.3 The values stated in inch-pound units are to be regarded
D374 Test Methods for Thickness of Solid Electrical Insu-
as the standard. The SI values given in parentheses are for
lation (Metric) D0374_D0374M
information only.
D495 Test Method for High-Voltage, Low-Current, DryArc
1.4 This standard does not purport to address all of the
Resistance of Solid Electrical Insulation
safety concerns, if any, associated with its use. It is the
D570 Test Method for Water Absorption of Plastics
responsibility of the user of this standard to establish appro-
D668 TestMethodsofMeasuringDimensionsofRigidRods
priate safety, health, and environmental practices and deter-
and Tubes Used for Electrical Insulation (Withdrawn
mine the applicability of regulatory limitations prior to use.
2020)
Specific hazard statements are given in 7.3, 22.1, and 22.2.
D689 Test Method for Internal Tearing Resistance of Paper
D695 Test Method for Compressive Properties of Rigid
NOTE 1—The test methods described herein are similar technically to
Plastics
those described in IEC Publication 60667-2. Not all of the tests in this
document are included in IEC 60667-2, and the procedures in the two D710 Specification for Vulcanized Fibre Sheets, Rolls,
publications are not completely identical; but it is expected that compa-
Rods, and Tubes Used for Electrical Insulation
rable results will be obtained from most of the procedures. Conduct
D785 Test Method for Rockwell Hardness of Plastics and
comparative tests if necessary before directly comparing results of tests
Electrical Insulating Materials
using the different procedures.
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 [e-mail]. For Annual Book of ASTM
Subcommittee D09.07 on Electrical Insulating Materials Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Jan. 1, 2021. Published February 2021. Originally the ASTM website.
approved in 1941. Last previous edition approved in 2014 as D619 – 14. DOI: The last approved version of this historical standard is referenced on
10.1520/D0619-21. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D619 − 21
D792 Test Methods for Density and Specific Gravity (Rela- thisdirectionmaybedesignatedasthecross-machinedirection
tive Density) of Plastics by Displacement or the weft direction. It is also known as cross direction.
D828 Test Method for Tensile Properties of Paper and
3.2.5 edgewise loading, v—mechanical force applied in the
PaperboardUsingConstant-Rate-of-ElongationApparatus
plane of the original sheet or plate.
D952 Test Method for Bond or Cohesive Strength of Sheet
3.2.6 flatwise loading, v—mechanical force applied normal
Plastics and Electrical Insulating Materials
to the surfaces of the original sheet or plate.
D1711 Terminology Relating to Electrical Insulation
D6054 Practice for Conditioning Electrical Insulating Mate-
3 4. Conditioning
rials for Testing (Withdrawn 2012)
4.1 Vulcanized fibre shall be conditioned for mechanical
2.2 IEC Standard:
tests in accordance with Practice D6054, using ProcedureAfor
IEC 60667-2 Specification for Vulcanized Fibre for Electri-
conditioning material 0.045 in. (1.14 mm) and under in
cal Purposes–Part 2: Methods of Test
thickness, and Procedure B for conditioning material over
0.045 in. in thickness. In case of dispute in tests of materials
3. Terminology
over 0.045 in. in thickness, the material shall be exposed for
3.1 Definitions:
48 hatstandardlaboratoryatmospherepriortoconditioningby
3.1.1 For definitions of terms used in this standard refer to
Procedure B.
Terminology D1711.
4.2 Vulcanized fibre shall be conditioned for electrical tests
3.2 Definitions of Terms Specific to This Standard:
in accordance with Practice D6054, using ProcedureA. In case
3.2.1 In referring to the cutting of specimens and the
of dispute, a referee test shall be used in which the time of
application of the load, the following definitions of terms
exposure to standard laboratory atmosphere is increased to a
apply.These definitions of terms correspond to normal practice
minimum period of seven days for all thicknesses.
in the paper industry.
4.2.1 The following are the typical reasons to undertake
3.2.2 vulcanized fibre, n—a material made from chemically
conditioning of specimens: (1) for the purpose of bringing the
gelatinized cellulosic paper or board using zinc chloride as the
material into equilibrium with normal or average room condi-
gelatinizing agent.
tions of 23 °C and 50 % relative humidity, (2) to obtain
3.2.2.1 Discussion—The zinc chloride is subsequently re-
reproducible results regardless of the previous history of
moved by leaching. The resulting product, after being dried
exposure, or (3) to subject the material to various conditions of
and finished by calendering, is a material of partially regener-
temperatureorhumidityinordertopredictitsservicebehavior.
ated cellulose in which the fibrous structure is retained in
4.2.2 It is possible that the conditioning of Procedure B
varying degrees depending on the grade of paper used and on
prescribedinPracticeD6054toobtainreproducibleresultswill
the processing conditions. Material up to about 2.54 mm in
give physical values somewhat higher or somewhat lower than
thickness is produced by bonding multiple layers of paper (or
the values at equilibrium under normal conditions, depending
board) after chemical treatment. Vulcanized fibre thicker than
upon the test. This procedure for conditioning is used because
2.54 mm is typically produced by laminating multiple plies of
of the relatively short time required.To bring the material to an
vulcanized fibre together. Vulcanized fibre does not contain
equilibrium condition in a controlled humidity would require a
vulcanized rubber or sulfur as the name might imply. Thin
long period of time which might extend over many months, for
vulcanized fibre has sometimes been termed “fish paper.” For
example, for thicknesses over 25 mm.The exact length of time
more detail on vulcanized fibre refer to Specification D710.
would depend upon such factors as thickness, grade, and
3.2.3 lengthwise (LW), adj—the direction of the sheet which
previous history of the specimens, and it would be too long for
is strongest in flexure.
ordinary commercial test purposes. It is probably possible to
3.2.3.1 Discussion—This is also known as the machine
reducethetimeofexposureforsomeverythinsizesofmaterial
direction. It is the lengthwise direction in which the paper is
conditionedinaccordancewithProcedureA,butsufficientdata
formed and travels on the paper machine, wire, or cylinder.
on the various thicknesses are not yet available to permit a
Since making paper (which form the plies of vulcanized fibre)
decision to be made.
is a directional process, vulcanized fibre’s properties differ
significantly between machine direction and cross direction.
METHODS APPLICABLE TO SHEETS, TUBES, AND
For some materials, including the raw materials used for the
RODS
manufacture of materials considered herein, this direction may
be designated as the warp direction.
5. Water Absorption
3.2.4 crosswise (CW), adj—the direction of the sheet which
5.1 Significance and Use—This test method is a guide for
is at 90° to the lengthwise direction, and which is normally the
the proportion of water absorbed in vulcanized fibre sheets,
weakest direction in flexure.
rolls, tubes, and rods and to the effects thereof on certain
3.2.4.1 Discussion—For some materials, including the raw
electrical and mechanical properties. It also is useful in
materials used for manufacture of materials considered herein,
determining the uniformity of quality in these materials.
5.2 Procedure—Determine water absorption in accordance
with Test Method D570 on specimens dried in an oven for 1 h
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. at 105 to 110 °C prior to immersion in water.
D619 − 21
6. Ash 7.5 Precision and Bias:
7.5.1 This test method has been used for many years, but no
6.1 Significance and Use—This test method provides a
information has been presented to ASTM upon which to base
procedure for determining the amount of ash of a dried
a precision statement. No activity has been planned to develop
specimen, something potentially useful in determining the
such information.
continuity of quality.
7.5.2 This test method has no bias because the value for
6.2 Test Specimen—The test specimen shall consist of 2 to 5
percentage of silica is determined solely in terms of this test
g of vulcanized fibre in the form of finely divided particles,
method itself.
such as millings or filings.
8. Volatile Matter
6.3 Procedure—Dry the test specimen for2hat105to110
8.1 Significance and Use—The presence of high levels of
°C and weigh. Then ignite the specimen to constant weight in
volatile matter has the potential to be detrimental to the use of
a crucible and reweigh. Calculate the percentage of ash, based
vulcanized fibre sheets, rolls, tubes, and rods in some electrical
on the weight of the dried specimen.
applications. It is possible that data on volatile content will be
6.4 Report—Report the following information:
helpful to determine the suitability for a particular application
6.4.1 Identification of the material, and
and to determine the continuity of quality.
6.4.2 The percentage by weight of ash.
8.2 Purpose—This test method is intended for the rapid
6.5 Precision and Bias:
determination of the amount of moisture and other volatile
6.5.1 This test method has been used for many years, but no
matter in vulcanized fibre of all grades and thicknesses.
information has been presented to ASTM upon which to base
8.3 Test Specimens—Prepare the test specimen which con-
a precision statement. No activity has been planned to develop
sists of the minimum number of pieces of fibre required to give
such information.
a total weight of at least 1 g, as follows:
6.5.2 This test method has no bias because the value for
8.3.1 Sheets—For sheets less than ⁄16 in. (1.59 mm) in
percentage of ash is determined solely in terms of this test
thickness, the pieces for the test specimen shall be 75 by
method itself.
25 mm by the thickness of the sheet; for sheets ⁄16 in. and over
in thickness, the pieces for the test specimen shall be 75 by
7. Silica
3 mm by the thickness of the sheet. The pieces shall be
7.1 Significance and Use—This test method is useful in
band-sawed or sheared from the sample so as to produce
determiningthecontinuityofqualityofvulcanizedfibresheets,
smooth edges free of cracks. The sawed faces shall be sanded
rolls, tubes, and rods and in providing a means of evaluating
orfiledtoremoveanyprotrudingsectionsthatmightbebroken
changes in the leaching medium and the efficiency of the
offduringthetest.Thesampleshallbesawedslowlysothatthe
leaching process.
fibre is not heated appreciably. The thickness of the specimens
shall be measured to the nearest 0.001 in. (0.025 mm) in the
7.2 Test Specimen—The test specimen shall consist of
direction perpendicular to the natural faces of the original
approximately3gof vulcanized fibre in the form of finely
sample.
divided particles, such as millings or filings.
8.3.2 Tubes—For tubes less than ⁄16 in. (1.59 mm) in wall
7.3 Procedure—Dry the test specimen for1hat105to110
thickness, the pieces for the test specimen shall be 25 mm
°C. Transfer the dried specimen to a crucible and slowly ignite
lengths. For tubes ⁄16 in. and over in wall thickness, the pieces
it to constant weight. Wet the ash with distilled water and
for the test specimen shall be 3 mm lengths slowly cut with a
transfer to a heat-resistant glass beaker. Add about 75 mL of
band saw.
HCl (sp gr 1.19) and cover the beaker with a watchglass.
8.3.3 Rods—For rods less than ⁄16 in. (4.76 mm) in
Evaporate the contents of the beaker to dryness. To the residue
diameter, the pieces for the test specimen shall consist of
slowly add 10 mL of HCl (sp gr 1.19) followed by 75 mL of
continuous lengths. For rods ⁄16 in. and over in diameter, the
distilled water. Filter the mixture through ashless filter paper
pieces for the test specimen shall be 3 mm lengths slowly cut
and wash with cold water, then with warm water, until the
with a band saw.
filtrate is free of chlorides. Ignite the filter paper to constant
8.4 Procedure—Test three specimens, each consisting of
weight in a weighed platinum crucible. Then add 4 mL of HF
one or more pieces of fibre as required, individually. Weigh
(48to60 %)andapplyheatuntilallwhitefumesaredrivenoff.
eachspecimentothenearest1mg,andplaceitinamechanical
Cool and weigh the crucible. The difference between this
convection oven maintained at a temperature of 135 62°C
weight and the previous one indicates silicon present as silica.
and heated for the period prescribed in the following table.
The results shall be expressed as a percentage of the weight of
Specimens less than ⁄32 in. (0.80 mm) in thickness shall be
the dried specimen. (Warning—Both hydrochloric acid (HCl)
weighed (but not heated) in a weighing bottle.
and hydrofluoric acid (HF) are corrosive and toxic. Take care
Size Heating Period, h
to avoid spillage and contact with the skin. Evaporate solutions
Sheets Under ⁄16 in. (1.59 mm), in thickness 2
of these acids in a well-ventilated fume hood.)
⁄16 and over in thickness 4
Tubes Under ⁄16 in. in wall thickness 2
7.4 Report—Report the following information:
⁄16 in. and over in wall thickness 4
7.4.1 Identification of the material, and
Rods Under ⁄16 in. (4.76 mm) in diameter 2
⁄16 in. and over in diameter 4
7.4.2 The percentage by weight of silica.
D619 − 21
8.4.1 Remove the specimens from the oven, cool in a METHODS APPLICABLE TO SHEETS
desiccator, and weigh to the nearest 1 mg. The difference
NOTE 2—In addition to the test methods for sheets and rolls covered in
between the original weight and the final weight of the
the following Sections 10–23, inclusive, the methods described in
specimens shall be considered as the volatile matter content.
Sections5–9 are also applicable to sheet and roll materials.Any mention
of sheets also refers to vulcanized fibre in rolls
8.5 Calculation—Calculatethepercentageofvolatilematter
content of the specimen as follows:
10. Tensile Strength
Volatile matter, % 5 @~W 2 W !/W # 3100 (1)
1 2 2
10.1 Significance and Use—Tensile strength is of impor-
tance as a measurement of uniformity and quality of the
where:
material. It also serves to indicate its ability to withstand stress
W = original weight of specimen, and
in application and service.
W = final weight of specimen.
10.2 For sheets 0.030 in. (0.762 mm) and under in
8.6 Report—Report the following information:
thickness,determinethetensilestrengthinaccordancewiththe
8.6.1 Color and dimensions of the specimen, and
procedure described in Test Method D828.
8.6.2 Percentage of volatile matter.
10.3 For sheets over 0.030 in. (0.762 mm) in thickness,
8.7 Precision and Bias:
determinethetensilestrengthinaccordancewiththeprocedure
8.7.1 This test method has been used for man
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D619 − 14 D619 − 21 An American National Standard
Standard Test Methods for
Vulcanized Fibre Used for Electrical Insulation
This standard is issued under the fixed designation D619; 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*
1.1 These test methods cover the procedures for testing vulcanized fibre sheets, rolls, tubes, and rods of such grades as can be used
for electrical insulation.
1.2 The procedures appear in the following sections:
Procedure Section
Arc Resistance 23
Ash 6
Bond Strength (Ply Adhesion) 16
Bursting Strength 14
Compressive Strength 12, 25, 30
Conditioning 4
Density 17, 26, 32
Dielectric Strength 18, 27
Dimensional Measurements 28, 33
Flammability 22
Flexural Strength 13, 31
Silica 7
Tearing Strength 11
Tensile Strength 10, 24, 29
Thickness (Sheets) 20
Resistance to Impact 15
Rockwell Hardness 19
Volatile Matter 8
Water Absorption 5
Zinc Chloride 9
Procedure Section
Arc resistance 23
Ash 6
Bond strength (ply adhesion) 16
Bursting strength 14
Compressive strength 12, 25, 30
Conditioning 4
Density 17, 26, 32
Dielectric strength 18, 27
Dimensional measurements 28, 33
Flammability 22
Flexural strength 13, 31
Silica 7
Tearing strength 11
Tensile strength 10, 24, 29
These test methods are under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and are the direct responsibility of Subcommittee
D09.07 on Electrical Insulating Materials
Current edition approved Nov. 1, 2014Jan. 1, 2021. Published December 2014February 2021. Originally approved in 1941. Last previous edition approved in 20042014
as D619 – 99 (2004)D619 – 14. which was withdrawn January 2013 and reinstated in November 2014. DOI: 10.1520/D0619-14.DOI: 10.1520/D0619-21.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D619 − 21
Thickness (sheets) 20
Resistance to impact 15
Rockwell hardness 19
Volatile matter 8
Water absorption 5
Zinc chloride 9
1.3 The values stated in inch-pound units are to be regarded as the standard. The SI values given in parentheses are for information
only.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. Specific hazard statements are given in 7.3, 22.1, and 22.2.
NOTE 1—The test methods described herein are similar technically to those described in IEC Publication 60667-2. Not all of the tests in this document
are included in IEC 60667-2, and the procedures in the two publications are not completely identical; but it is expected that comparable results will be
obtained from most of the procedures. Conduct comparative tests if necessary before directly comparing results of tests using the different procedures.
NOTE 1—The test methods described herein are similar technically to those described in IEC Publication 60667-2. Not all of the tests in this document
are included in IEC 60667-2, and the procedures in the two publications are not completely identical; but it is expected that comparable results will be
obtained from most of the procedures. Conduct comparative tests if necessary before directly comparing results of tests using the different procedures.
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.
2. Referenced Documents
2.1 ASTM Standards:
D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at
Commercial Power Frequencies
D202 Test Methods for Sampling and Testing Untreated Paper Used for Electrical Insulation
D229 Test Methods for Rigid Sheet and Plate Materials Used for Electrical Insulation
D256 Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics
D348 Test Methods for Rigid Tubes Used for Electrical Insulation (Withdrawn 2020)
D349 Test Methods for Laminated Round Rods Used for Electrical Insulation (Withdrawn 2020)
D374 Test Methods for Thickness of Solid Electrical Insulation (Metric) D0374_D0374M
D495 Test Method for High-Voltage, Low-Current, Dry Arc Resistance of Solid Electrical Insulation
D570 Test Method for Water Absorption of Plastics
D668 Test Methods of Measuring Dimensions of Rigid Rods and Tubes Used for Electrical Insulation (Withdrawn 2020)
D689 Test Method for Internal Tearing Resistance of Paper
D695 Test Method for Compressive Properties of Rigid Plastics
D710 Specification for Vulcanized Fibre Sheets, Rolls, Rods, and Tubes Used for Electrical Insulation
D785 Test Method for Rockwell Hardness of Plastics and Electrical Insulating Materials
D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
D828 Test Method for Tensile Properties of Paper and Paperboard Using Constant-Rate-of-Elongation Apparatus
D952 Test Method for Bond or Cohesive Strength of Sheet Plastics and Electrical Insulating Materials
D1711 Terminology Relating to Electrical Insulation
D6054 Practice for Conditioning Electrical Insulating Materials for Testing (Withdrawn 2012)
2.2 IEC Standard:
IEC 60667-2 Specification for Vulcanized Fibre for Electrical Purposes–Part 2: Methods of Test
3. Terminology
3.1 Definitions—For definitions of terms used in this standard refer to Terminology D1711.
3.1 Definitions:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from American National Standards Institute, 11 W. 42nd St., 13thInstitute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.10036, http://www.ansi.org.
D619 − 21
3.1.1 For definitions of terms used in this standard refer to Terminology D1711.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 In referring to the cutting of specimens and the application of the load, the following definitions of terms apply. These
definitions of terms correspond to normal practice in the paper industry.
3.2.2 vulcanized fibre, n—a material made from chemically gelatinized cellulosic paper or board using zinc chloride as the
gelatinizing agent.
3.2.2.1 Discussion—
The zinc chloride is subsequently removed by leaching. The resulting product, after being dried and finished by calendering, is a
material of partially regenerated cellulose in which the fibrous structure is retained in varying degrees depending on the grade of
paper used and on the processing conditions. Material up to about 3.2 mm2.54 mm in thickness is produced by bonding multiple
layers of paper (or board) after chemical treatment. Vulcanized fibre thicker than 3.2 mm2.54 mm is typically produced by
laminating multiple plies of vulcanized fibre together. Vulcanized fibre does not contain vulcanized rubber or sulfur as the name
might imply. Thin vulcanized fibre has sometimes been termed “fish paper.” For more detail on vulcanized fibre refer to
Specification D710.
3.2.3 lengthwise (LW), adj—the direction of the sheet which is strongest in flexure.
3.2.3.1 Discussion—
This is also known as the machine direction. It is the lengthwise direction in which the paper is formed and travels on the paper
machine, wire, or cylinder. Since making paper (which form the plies of vulcanized fibre) is a directional process, vulcanized
fibre’s properties differ significantly between machine direction and cross direction. For some materials, including the raw
materials used for the manufacture of materials considered herein, this direction may be designated as the warp direction.
3.2.4 crosswise (CW), adj—the direction of the sheet which is at 90° to the lengthwise direction, and which is normally the weakest
direction in flexure.
3.2.4.1 Discussion—
For some materials, including the raw materials used for manufacture of materials considered herein, this direction may be
designated as the cross-machine direction or the weft direction. It is also known as cross direction.
3.2.5 edgewise loading, v—mechanical force applied in the plane of the original sheet or plate.
3.2.6 flatwise loading, v—mechanical force applied normal to the surfaces of the original sheet or plate.
4. Conditioning
4.1 Vulcanized fibre shall be conditioned for mechanical tests in accordance with Practice D6054, using Procedure A for
conditioning material 0.045 in. (1.14 mm) and under in thickness, and Procedure B for conditioning material over 0.045 in. in
thickness. In case of dispute in tests of materials over 0.045 in. in thickness, the material shall be exposed for 48 h at standard
laboratory atmosphere prior to conditioning by Procedure B.
4.2 Vulcanized fibre shall be conditioned for electrical tests in accordance with Practice D6054, using Procedure A. In case of
dispute, a referee test shall be used in which the time of exposure to standard laboratory atmosphere is increased to a minimum
period of seven days for all thicknesses.
4.2.1 The following are the typical reasons to undertake conditioning of specimens: (1) for the purpose of bringing the material
into equilibrium with normal or average room conditions of 23°C 23 °C and 50%50 % relative humidity, (2) to obtain reproducible
results regardless of the previous history of exposure, or (3) to subject the material to various conditions of temperature or humidity
in order to predict its service behavior.
4.2.2 It is possible that the conditioning of Procedure B prescribed in Practice D6054 to obtain reproducible results will give
physical values somewhat higher or somewhat lower than the values at equilibrium under normal conditions, depending upon the
test. This procedure for conditioning is used because of the relatively short time required. To bring the material to an equilibrium
condition in a controlled humidity would require a long period of time which might extend over many months, for example, for
thicknesses over 25 mm. The exact length of time would depend upon such factors as thickness, grade, and previous history of
the specimens, and it would be too long for ordinary commercial test purposes. It is probably possible to reduce the time of
D619 − 21
exposure for some very thin sizes of material conditioned in accordance with Procedure A, but sufficient data on the various
thicknesses are not yet available to permit a decision to be made.
METHODS APPLICABLE TO SHEETS, TUBES, AND RODS
5. Water Absorption
5.1 Significance and Use—This test method is a guide for the proportion of water absorbed in vulcanized fibre sheets, rolls, tubes,
and rods and to the effects thereof on certain electrical and mechanical properties. It also is useful in determining the uniformity
of quality in these materials.
5.2 Procedure—Determine water absorption in accordance with Test Method D570 on specimens dried in an oven for 1 h at 105
to 110°C 110 °C prior to immersion in water.
6. Ash
6.1 Significance and Use—This test method provides a procedure for determining the amount of ash of a dried specimen,
something potentially useful in determining the continuity of quality.
6.2 Test Specimen—The test specimen shall consist of 2 to 5 g of vulcanized fibre in the form of finely divided particles, such as
millings or filings.
6.3 Procedure—Dry the test specimen for 2 h at 105 to 110°C 110 °C and weigh. Then ignite the specimen to constant weight
in a crucible and reweigh. Calculate the percentage of ash, based on the weight of the dried specimen.
6.4 Report—Report the following information:
6.4.1 Identification of the material, and
6.4.2 The percentage by weight of ash.
6.5 Precision and Bias:
6.5.1 This test method has been used for many years, but no information has been presented to ASTM upon which to base a
precision statement. No activity has been planned to develop such information.
6.5.2 This test method has no bias because the value for percentage of ash is determined solely in terms of this test method itself.
7. Silica
7.1 Significance and Use—This test method is useful in determining the continuity of quality of vulcanized fibre sheets, rolls,
tubes, and rods and in providing a means of evaluating changes in the leaching medium and the efficiency of the leaching process.
7.2 Test Specimen—The test specimen shall consist of approximately 3 g of vulcanized fibre in the form of finely divided particles,
such as millings or filings.
7.3 Procedure—Dry the test specimen for 1 h at 105 to 110°C. 110 °C. Transfer the dried specimen to a crucible and slowly ignite
it to constant weight. Wet the ash with distilled water and transfer to a heat-resistant glass beaker. Add about 75 mL of HCl (sp
gr 1.19) and cover the beaker with a watchglass. Evaporate the contents of the beaker to dryness. To the residue slowly add 10
mL of HCl (sp gr 1.19) followed by 75 mL of distilled water. Filter the mixture through ashless filter paper and wash with cold
water, then with warm water, until the filtrate is free of chlorides. Ignite the filter paper to constant weight in a weighed platinum
crucible. Then add 4 mL of HF (48 to 60 %) and apply heat until all white fumes are driven off. Cool and weigh the crucible. The
difference between this weight and the previous one indicates silicon present as silica. The results shall be expressed as a
percentage of the weight of the dried specimen. (Warning—Both hydrochloric acid (HCl) and hydrofluoric acid (HF) are corrosive
and toxic. Take care to avoid spillage and contact with the skin. Evaporate solutions of these acids in a well-ventilated fume hood.)
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7.4 Report—Report the following information:
7.4.1 Identification of the material, and
7.4.2 The percentage by weight of silica.
7.5 Precision and Bias:
7.5.1 This test method has been used for many years, but no information has been presented to ASTM upon which to base a
precision statement. No activity has been planned to develop such information.
7.5.2 This test method has no bias because the value for percentage of silica is determined solely in terms of this test method itself.
8. Volatile Matter
8.1 Significance and Use—The presence of high levels of volatile matter has the potential to be detrimental to the use of vulcanized
fibre sheets, rolls, tubes, and rods in some electrical applications. It is possible that data on volatile content will be helpful to
determine the suitability for a particular application and to determine the continuity of quality.
8.2 Purpose—This test method is intended for the rapid determination of the amount of moisture and other volatile matter in
vulcanized fibre of all grades and thicknesses.
8.3 Test Specimens—Prepare the test specimen which consists of the minimum number of pieces of fibre required to give a total
weight of at least 1 g, as follows:
8.3.1 Sheets—For sheets less than ⁄16 in. (1.59 mm) in thickness, the pieces for the test specimen shall be 75 by 25 mm 25 mm
by the thickness of the sheet; for sheets ⁄16 in. and over in thickness, the pieces for the test specimen shall be 75 by 3 mm 3 mm
by the thickness of the sheet. The pieces shall be band-sawed or sheared from the sample so as to produce smooth edges free of
cracks. The sawed faces shall be sanded or filed to remove any protruding sections that might be broken off during the test. The
sample shall be sawed slowly so that the fibre is not heated appreciably. The thickness of the specimens shall be measured to the
nearest 0.001 in. (0.025 mm) in the direction perpendicular to the natural faces of the original sample.
8.3.2 Tubes—For tubes less than ⁄16 in. (1.59 mm) in wall thickness, the pieces for the test specimen shall be 25-mm 25 mm
lengths. For tubes ⁄16 in. and over in wall thickness, the pieces for the test specimen shall be 3-mm 3 mm lengths slowly cut with
a band saw.
8.3.3 Rods—For rods less than ⁄16 in. (4.76 mm) in diameter, the pieces for the test specimen shall consist of continuous lengths.
For rods ⁄16 in. and over in diameter, the pieces for the test specimen shall be 3-mm 3 mm lengths slowly cut with a band saw.
8.4 Procedure—Test three specimens, each consisting of one or more pieces of fibre as required, individually. Weigh each
specimen to the nearest 1 mg, and place it in a mechanical convection oven maintained at a temperature of 135 6 2°C 2 °C and
heated for the period prescribed in the following table. Specimens less than ⁄32 in. (0.80 mm) in thickness shall be weighed (but
not heated) in a weighing bottle.
Size Heating Period, h
Sheets Under ⁄16 in. (1.59 mm), in thickness 2
⁄16 and over in thickness 4
Tubes Under ⁄16 in. in wall thickness 2
⁄16 in. and over in wall thickness 4
Rods Under ⁄16 in. (4.76 mm) in diameter 2
⁄16 in. and over in diameter 4
Heating
Size
Period, h
Sheets Under ⁄16 in. (1.59 mm), in thickness 2
⁄16 and over in thickness 4
Tubes Under ⁄16 in. in wall thickness 2
⁄16 in. and over in wall thickness 4
Rods Under ⁄16 in. (4.76 mm) in diameter 2
⁄16 in. and over in diameter 4
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8.4.1 Remove the specimens from the oven, cool in a desiccator, and weigh to the nearest 1 mg. The difference between the
original weight and the final weight of the specimens shall be considered as the volatile matter content.
8.5 Calculation—Calculate the percentage of volatile matter content of the specimen as follows:
Volatile matter, %5 @~W 2 W !/W # 3100 (1)
1 2 2
where:
W = original weight of specimen, and
W = final weight of specimen.
8.6 Report—Report the following information:
8.6.1 Color and dimensions of the specimen, and
8.6.2 Percentage of volatile matter.
8.7 Precision and Bias:
8.7.1 This test method has been used for many years, but no information has been presented to ASTM upon which to base a
precision statement. No activity has been planned to develop such information.
8.7.2 This test method has no bias because the value for percentage of volatile matter is determined solely in term
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