ASTM D4325-20

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: D4325 − 13 D4325 − 20
Standard Test Methods for
Nonmetallic Semi-Conducting and Electrically Insulating
Rubber Tapes
This standard is issued under the fixed designation D4325; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 These test methods cover the methods and procedures for testing electrically insulating and semi-nonmetallic conducting
semi-conducting rubber tapes designed for splicing, terminating, and sheath repair of electrical wire and cable.
1.2 The test methods appear in the following sections:
Section
Referenced Documents 2
Conditioning 5 – 6
Dielectric Strength 35 – 40
Dimensions 11 – 16
Dissipation Factor 22 – 26
Elongation 17 – 21
Heat Exposure 46 – 49
Fusion 7 – 10
Ozone Resistance 41 – 45
Permittivity 22 – 26
Sample Requirements 4
Tensile Strength 17 – 21
Volume Resistivity 27 – 34
Ultraviolet and Weather Resistance 50 – 54
Section
Referenced Documents 2
Conditioning 5-6
Dielectric Strength 35 – 40
Dimensions 11 – 16
Dissipation Factor 22 – 26
Elongation 17 – 21
Heat Exposure 46 – 49
Fusion 7 – 10
Ozone Resistance 41 – 45
Permittivity 22 – 26
Sample Requirements 4
Tensile Strength 17 – 21
Volume Resistivity 27 – 34
Ultraviolet and Weather Resistance 50 – 54
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 Flexible and Rigid Electrical Insulating Materials.
Current edition approved Nov. 1, 2013Aug. 1, 2020. Published December 2013September 2020. Originally approved in 1997. Last previous edition approved in 20082013
as D4325 – 08.D4325 – 13. DOI: 10.1520/D4325-13.10.1520/D4325-20.
*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
D4325 − 20
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to
inch-pound units that are provided for information only and are not considered standard.
NOTE 1—There is no IEC equivalent to these methods.
1.4 Unless otherwise stated, measurements are made on tapes from which the removable separator has been removed.
1.5 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. For specific precaution statementswarning statement see 43.1.
1.6 This is a fire-test response standard.
1.6 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
D150 Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation
D257 Test Methods for DC Resistance or Conductance of Insulating Materials
D374D374/D374M Test Methods for Thickness of Solid Electrical Insulation (Metric) D0374_D0374M
D412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension
D470 Test Methods for Crosslinked Insulations and Jackets for Wire and Cable
D750 Practice for Rubber Deterioration Using Artificial Weathering Apparatus
D4388 Specification for Nonmetallic Semi-Conducting and Electrically Insulating Rubber Tapes
D4496 Test Method for D-C Resistance or Conductance of Moderately Conductive Materials
E591 Practice for Safety and Health Requirements Relating to Occupational Exposure to Ozone (Withdrawn 1990)
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 fusion, n—that property of rubber tape which causes adjacent layers of tape to become bonded (amalgamated) or adhered
together when the tape is stretched and wound upon itself in layers.
SAMPLING
4. Sample and Specimen Requirements
4.1 Unless otherwise required by the detailed product specifications, take the rubber tapes at random from each shipment as
follows:
Number of Rolls Number of Sample
in Shipment Rolls
50 to 200 2
201 to 500 3
501 to 1000 4
1001 to 5000 5
4.2 For shipments in excess of 5000 rolls, take one additional roll for each additional 1000 rolls or fraction thereof.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Withdrawn. The last approved version of this historical standard is referenced on www.astm.org.
D4325 − 20
4.3 A shipment consists of material shipped or intended for shipment to a customer and covered by one bill of lading.
4.4 Test each sample roll in conformance to all requirements of the specification.
4.5 All test methods in this standard are intended to produce a single value for a single roll. Any reference to averaging of
measurements refers to test averaging on a single roll and not to the average of all sample rolls.
4.6 Remove and discard at least 610 mm (24 in.) of the outer layer of each roll before taking test specimens.
4.7 Remove the test specimen from the roll at a slow, uniform rate without jerking.
CONDITIONING
5. Significance and Use
5.1 The physical and electrical properties, including break strength, elongation, dielectric strength, dissipation factor, permittivity,
fusion, etc., will vary with temperature and moisture content. Control the temperature and moisture content of the sample for these
test methods to yield consistent and reproducible results.
6. Procedure
6.1 For referee purposes, subject the rolls to standard atmospheric conditions of 23 6 2 °C (73.4 6 3.6 °F) and 50 6 2 % relative
humidity for a minimum period of 16 h before specimens are removed for test.
6.2 Unless otherwise specified, condition all test specimens for a period of 1 h and conduct the tests in a standard laboratory
atmosphere at 23 6 2 °C (73.4 6 3.6 °F) and 50 6 2 % relative humidity.
FUSION
7. Significance and Use
7.1 Fusion is responsible for holding the tape in place to form a permanent compressive force about a conductor or insulator in
actual application.
8. Apparatus
8.1 Winding Fixture—The winding fixture is designed to hold a metal rod at each end and is fitted with a crank or other device
to rotate the rod to allow the specimen to be wound thereon. Attach the fixture to a rigid support with the rod held in a horizontal
position.
8.2 Rods—Any suitable metal of 3-mm 3 mm (0.125-in.) diameter and a minimum of 229 mm (9.0 in.) in length. Rods shall be
cleaned with a suitable solvent such as acetone to remove residual oils and surface contamination.
8.3 Rule, graduated in inches, 762-mm 762 mm (30-in.) minimum length.
8.4 Rule, graduated in 0.4 mm ( ⁄64 in.).
8.5 Razor Blades.
8.6 Board, with 3-mm 3 mm (0.125-in.) diameter holes spaced about 50 mm (2 in.) apart on its surface to provide a base for
supporting the rods in a near-vertical position.
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9. Procedure
9.1 Prepare three specimens by cutting three strips of tape 280 mm (11 in.) in length from the sample roll selected and conditioned
in accordance with Sections 4 – 6. Prepare and wind specimens in a manner that prevents oils or other contaminants from getting
on the bonding surface of the tape.
9.2 Mount the rod horizontally in the winding fixture.
9.3 Attach the strip of tape near one end of the rod by winding the strip upon itself using 25 mm (1 in.) of the tape. Place the
762-mm 762 mm (30-in.) rule next to the 254-mm 254 mm (10-in.) tape strip. Stretch the tape strip to the desired length
corresponding to percent elongation as specified in the product specification (Specification D4388, Table 1).
9.4 Move the tape to the proper angle and rotate the rod so that the tape is wrapped on the rod with a one-half lap for a length
of 178 mm (7.0 in.). Maintain enough hand pressure at the end of the tape strip as it is wound around the mandrel to ensure that
it does not retract from its original elongation during the winding process. Care must be taken to avoid using so much hand pressure
as to further stretch the tape as it is wound.
9.5 Change the angle of the tape and repeat the procedure in 9.4 winding back toward the start of the first wrap so that the second
one-half overlap wrap is wound over the first wrap to provide a four layer build-up of tape.
9.6 After the final wrap, maintain constant pressure on the tape strip and score the tape with a new razor blade at the top of the
rod, parallel to the rod. Break the tape on the score line, removing the tab. Remove the test specimen from the fixture and roll the
specimen so formed between the palm of the hands for 5 to 10 s, being sure to roll up or down the entire length of the specimen.
This completes the preparation of the test specimen.
9.7 Insert the wrapped specimen in the holes in the base of the board and allow them to condition at 23.0 6 2 °C (73.4 6 3.6
°F) and 50 6 2 % relative humidity for 24 h. At the end of this period, if there is any flagging (end-lifting) of the tape, measure
the length of the flag to the nearest 0.4 mm ( ⁄64 in.), taking care not to cause additional unwrapping in the measuring operation
Record the maximum, minimum and average length of the flag.
10. Report
10.1 Report the following information:
10.1.1 Identification of the tape tested, and
10.1.2 Pass or fail depending on the requirements outlined in the product specification (see Specification D4388).
DIMENSIONS—LENGTH, WIDTH, AND THICKNESS AND THICKNESS
11. Significance and Use
11.1 Measurements of length, width, and thickness are necessary to ensure a customer is receiving the correct quantity of tape.
The thickness measurement is of particular value in controlling uniformity and providing design criteria, as well as being used in
the measurement of physical and electrical properties.
12. Apparatus
12.1 Steel Rule, capable of measuring to the nearest 0.4 mm ( ⁄64 in.).
12.2 Thickness Gage—Gauge—A dead weight dial micrometer as prescribed in Method C of Test Methods D374D374/D374M,
with the following modifications:
12.2.1 A micrometer with graduations to 0.01 mm (0.001 in).(0.001 in.).
D4325 − 20
12.2.2 A micrometer with a presser foot 6.35 6 0.25 mm (0.25 6 0.01 in.) in diameter exerting a total force of 2.50 6 0.03 N
(10.0 6 0.1 oz) force.
12.2.3 Calibrate the gagegauge for the actual load exerted by the presser foot.
13. Test Specimen
13.1 Select and condition the tape and specimen in accordance with Sections 4 – 6.
14. Procedure
14.1 Length Determination—Unwind the tape and separator from the roll, place it on a hard smooth surface, and measure the
length to the nearest 0.4 mm ( ⁄64 in.).
14.2 Thickness—Place the insulation surface against the anvil of the gagegauge with the separator side up holding the sample in
a manner such that it is smooth, yet not under tension. Lower the presser foot onto the tape in accordance with Test Methods
D374D374/D374M, allowing it to rest upon the tape for 2 s, and observe the reading on the dial. Take five measurements uniformly
distributed over the length of the tape specimen. Report the average thickness to the nearest 0.005 mm (0.0002 in.).(0.0002 in.).
14.3 Width—Place the test specimen, after conditioning, on a hard smooth surface. Measure the width perpendicular to the edge
with the steel scale to the nearest 0.40 mm ( ⁄64 in.).
15. Report
15.1 Report the following information:
15.1.1 Identification of the tape tested, and
15.1.2 Report the thickness, length, and width measured in accordance with the procedures outlined above.
16. Precision and Bias
16.1 Precision—This test method has been in use for many years, but no information has been presented to ASTM International
upon which to base a statement of precision. No activity has been planned to develop such information.
16.2 Bias—This test method has no bias because the values are determined solely in terms of this test method itself.
TENSILE STRENGTH AND ELONGATION
17. Significance and Use
17.1 The tensile strength of the tape is an important measure of uniformity, quality, and ability to withstand stress in service.
17.2 The elongation of a tape is important as a measure of uniformity and quality and provides a rough indication of how much
a workman will be able to stretch the tape in use for splicing, terminating, and repairing of wires and cables.
18. Test Specimen
18.1 The test sample consists of a single layer of tape that is approximately 610 mm (24 in.) long, with the removable separator
removed. Select and condition in accordance with Sections 4 – 6.
19. Procedure
19.1 Perform the tests for tensile strength and elongation in accordance with Test Methods D412, with the following exceptions:
D4325 − 20
19.1.1 Cut five test specimens from a single ply of tape (rubber and separator) that is free from visible defects using the ASTM
standard die, as shown in Fig. 1 (Die A) of Test Methods D412, except that the ends of the specimen cut from a 19-mm 19 mm
(0.75-in.) tape need not be full width. Place bench marks on the specimens as directed in Test Methods D412.
19.1.2 Measure the thickness in accordance with 14.2, removing the separator where it is not an integral part of the tape. Record
the appropriate thickness.
19.1.3 Where jaw breaks occur, discard the results and retest.
20. Report
20.1 Report the following information:
20.1.1 Average breaking strength expressed in MPa (psi), and
20.1.2 Average percent elongation.
21. Precision and Bias
21.1 See precision and bias statements of Test Methods D412 for general discussion of precision and bias of this test.
21.2 Precision—This test method has been in use for many years, but no information has been presented to ASTM International
upon which to base a statement of precision. No activity has been planned to develop such information.
21.3 Bias—This test method has no bias because the values for tensile strength and elongation are determined solely in terms of
this test method itself.
DISSIPATION FACTOR AND PERMITTIVITY
22. Significance and Use
22.1 The dissipation factor and permittivity of an electrically insulating rubber tape are properties of the material which are
important when it is used as high-voltage insulation.
22.2 Measurements of dissipation factor and permittivity are nondestructive tests that are helpful in determining the product
uniformity, moisture absorption, and changes in composition.
23. Conditioning
23.1 Unless otherwise specified, use the following condition
...