ASTM D2671-00(2007)e1

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An American National Standard
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Designation:D2671–00 (Reapproved 2007)
Standard Test Methods for
Heat-Shrinkable Tubing for Electrical Use
This standard is issued under the fixed designation D2671; 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 Department of Defense.
´ NOTE—Footnote 8 was deleted and the fire caveat in 68.2 was revised to meet Form and Style requirements editorially in
February 2007.
1. Scope responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 These test methods cover the testing of heat-shrinkable
bility of regulatory limitations prior to use. For specific hazard
tubing used for electrical insulation. Materials used include
statements, see Sections 5 and 68.2.
poly(vinyl chloride), polyolefins, fluorocarbon polymers, sili-
cone rubber, and other plastic or elastomeric compounds.
NOTE 1—These test methods are similar, but not identical to, those in
1.2 The values stated in inch-pound units are the standard
IEC 60684–2 (see also Note 9).
except for temperature, which shall be expressed in degrees
2. Referenced Documents
Celsius. Values stated in parentheses are for information only.
2.1 ASTM Standards:
1.3 The procedures appear in the following sections:
D149 Test Method for Dielectric Breakdown Voltage and
ASTM Method
Procedure Sections Reference
Dielectric Strength of Solid Electrical Insulating Materials
Adhesive Peel Strength 98-104
at Commercial Power Frequencies
Brittleness Temperature 40 D746
D257 Test Methods for DC Resistance or Conductance of
Color 55 and 56 D1535
Color Stability 57-62 D1535
Insulating Materials
Conditioning 7 D618
D412 Test Methods for Vulcanized Rubber and Thermo-
Copper Stability 93
plastic Elastomers—Tension
Corrosion Testing 89-95
Dielectric Breakdown 20-25 D149
D570 Test Method for Water Absorption of Plastics
Dimensions 8-13 D876
D618 Practice for Conditioning Plastics for Testing
Flammability 68-72 D876
D746 Test Method for Brittleness Temperature of Plastics
Fluid Resistance 63-67
Fungus Resistance 104-108
and Elastomers by Impact
Heat Resistance 49-54
D792 Test Methods for Density and Specific Gravity (Rela-
Heat Shock 26-30
tive Density) of Plastics by Displacement
Low-Temperature Properties 36-43
Restricted Shrinkage 14-19
D876 Test Methods for Nonrigid Vinyl Chloride Polymer
Selection of Test Specimens 6
Tubing Used for Electrical Insulation
Secant Modulus 81-84 D882
Storage Life 31-35 D882 Test Method for Tensile Properties of Thin Plastic
Specific Gravity 73 and 74 D792
Sheeting
Stress Modulus 85-88 D412
D1535 PracticeforSpecifyingColorbytheMunsellSystem
Tensile Strength and Ultimate Elongation 44-48 D412
D1711 Terminology Relating to Electrical Insulation
Thermal Endurance 96 and 97
Volume Resistivity 75-78 D257
D3418 Test Method for Transition Temperatures and En-
Water Absorption 79 and 80 D570
thalpies of Fusion and Crystallization of Polymers by
Melting Point 104-108 D3418
Differential Scanning Calorimetry
1.4 This is a fire-test-response standard.
E176 Terminology of Fire Standards
1.5 This standard does not purport to address all of the
2.2 Other Documents:
safety concerns, if any, associated with its use. It is the 3
MIL-STD 104 Limits for Electrical Insulation Color
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 D09.07 on Flexible and Rigid Insulating Materials. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Feb. 15, 2007. Published July 2007. Originally the ASTM website.
approved in 1967. Last previous edition approved in 2000 as D2671 – 00. DOI: AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
10.1520/D2671-00R07E01. Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D2671–00 (2007)
the result, and (2) the desire to eliminate redundant testing and use data
IEC Publication 216 Guide for the Determination of
generated during manufacturing process control, including that generated
Thermal Endurance Properties of Electrical Insulating
under Statistical Process Control (SPC) conditions, using equipment and
Materials
methods other than those specified herein. An example would be the use
IECPublication60684 SpecificationforFlexibleInsulating
of laser micrometers or optical comparators to measure dimensions.
Sleeving
ISO 846 Plastics—Evaluation of theAction of Microorgan- 5. Hazards
isms
5.1 Warning— Lethal voltages may be present during this
test. It is essential that the test apparatus, and all associated
3. Terminology
equipment that may be electrically connected to it, be properly
3.1 Definitions:
designed and installed for safe operation. Solidly ground all
3.1.1 For definitions pertaining to electrical insulation, refer
electrically conductive parts that any person might come in
to Terminology D1711.
contact with during the test. Provide means for use at the
3.1.2 For definitions pertaining to fire standards, refer to
completion of any test to ground any parts which: were at high
Terminology E176.
voltage during the test; may have acquired an induced charge
3.1.3 heat-shrinkable tubing, n—tubing that will reduce in
during the test; may retain a charge even after disconnection of
diameter from an expanded size to a predetermined size by the
the voltage source. Thoroughly instruct all operators in the
application of heat.
proper way to conduct tests safely. When making high voltage
3.2 Definitions of Terms Specific to This Standard:
tests, particularly in compressed gas or in oil, the energy
3.2.1 brittleness temperature, n—the temperature at which
released at breakdown may be suffıcient to result in fire,
50 % of the specimens fail when the specified number are
explosion, or rupture of the test chamber. Design test equip-
tested using the apparatus and conditions specified.
ment, test chambers, and test specimens so as to minimize the
3.2.2 concentricity, n—the ratio expressed in percent of the
possibility of such occurrences and to eliminate the possibility
minimum wall thickness to the maximum wall thickness.
of personal injury. (See Section 23.)
3.2.3 longitudinal change, n—the change in length, either
5.2 Flammable Solvents:
positive or negative, that occurs when the tubing is allowed to
5.2.1 Methylethylketoneisavolatile,flammablesolvent.It
freely recover at the recommended recovery temperature,
should be handled in an area having good ventilation, such as
expressed as a percentage of the as supplied or expanded
a laboratory hood and away from sources of ignition. See
length.
Section 100.
3.2.4 low-temperature flexibility, n—the resistance to crack-
ing of tubing when wrapped around prescribed mandrels at
6. Selection of Test Specimens
specified temperatures.
6.1 Select a sufficient number of pieces of tubing in such
3.2.5 restricted shrinkage, n—shrinkage of the tubing at a
manner as to be representative of the shipment.
prescribed temperature over a specially designed mandrel
6.2 Cut specimens, free of kinks, from the sample selected
whose smallest diameter is greater than the fully shrunk size
under 6.1. Cut perpendicular to the longitudinal axis of the
andwhoselargestdiameterislessthantheexpandedsizeofthe
tubing and in such manner that the specimen has cleanly cut
tubing.
square edges.
3.2.6 storage-life, heat-shrinkable tubing, n—the length of
6.3 Unless otherwise stated, test specimens in the com-
time that the tubing will retain its specified expanded and
pletely shrunk condition.
recovered dimensions under storage at a specified temperature.
7. Conditioning
4. Significance and Use
7.1 When specified, condition tubing in accordance with
4.1 These test methods include most of the important tests
Practice D618 using Procedure A, except use a conditioning
used to characterize heat-shrinkable tubing. They are intended
time of 4 h. In cases where tests are performed on specimens
primarily for, but not limited to, extruded heat-shrinkable
in the shrunk state, condition prior to testing, but after heat
tubing.
shrinking.
4.2 Variations in these test methods or alternate contempo-
rary methods of measurement may be used to determine the
DIMENSIONS
values for the properties in this standard provided such
methodsensurequalitylevelsandmeasurementaccuracyequal
8. Significance and Use
to or better than those prescribed herein. It is the responsibility
8.1 Inside Diameter—The inside diameter of tubing before
of the organizations using alternate test methods to be able to
and after heat-shrinking is an important factor in selecting
demonstrate this condition. In cases of dispute, the methods
tubing of the proper size to slip easily over an object and to
specified herein shall be used.
conform tightly after shrinkage.
NOTE 2—Provision for alternate methods is necessary because of (1)
8.2 Wall Thickness—Wall thickness measurements are use-
the desire to simplify procedures for specific applications without altering
ful in providing design data and in calculating certain physical
and electrical properties of the tubing.
8.3 Concentricity—A thin wall area, due to variation in
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. processing, may lead to equipment failure. It is important,
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D2671–00 (2007)
therefore, both in extrusion of the tubing, and its expansion with 11.2.1 and 11.2.2, calculate the concentricity (C) of the
prior to shrinkage in end-use, that concentricity be held above expanded and recovered tubing respectively, using the follow-
a specified limit to ensure proper performance of the tubing. ing equation:
8.4 Length—The length, both before and after heat-
C 5 100 ~M9/M8! (1)
shrinking, is important in the determination of proper fit of the
where:
tubing in end-use.
M8 = maximum thickness, in. (mm), and
M 9 = minimum thickness, in. (mm).
9. Apparatus
11.4 Measuring Length:
9.1 Mandrels—A series of steel rods suitable for insertion
11.4.1 Using the steel scale, measure the length to the
into the tubing including the tapered gages described under
nearest ⁄32 in. or 1 mm.
Test Methods D876, may be used.
11.4.2 Allow the specimens to recover under heat as de-
9.2 Micrometers, mandrel anvil and indicator set accurate to
scribed in 11.1.3 and 11.1.4. Measure the length after recovery.
at least 0.001 in. or 0.02 mm.
Record the length in the expanded and recovered state.
9.3 Steel Scale, graduated in ⁄64-in. or 0.5-mm divisions.
11.5 Calculating Longitudinal Change— From the mea-
9.4 Oven, forced-convection type, capable of maintaining
surements of expanded and recovered length made in accor-
temperature to within 6 5 °C.
dance with 11.4.1 and 11.4.2, calculate the percent longitudinal
change using the following equation:
10. Test Specimens
Percent longitudinal change 5 100 ~L8 2 L9!/L9 (2)
10.1 Cut three straight lengths of expanded tubing, each 6
in. (150 mm) long, from the sample as directed in 6.2 for each
where:
test performed.
L8 = recovered length, in. (mm), and
L9 = expanded length, in. (mm).
11. Procedure
11.1 Measuring Inside Diameter:
12. Report
11.1.1 Select a mandrel that will just fit into the specimen
12.1 Report the following information:
and insert the mandrel into the expanded tubing for a distance
12.1.1 Identification of the tubing,
of 1 in. (25 mm).
12.1.2 Inside diameter of the tubing in the expanded and in
the recovered state,
NOTE 3—Should the tubing specimens tend to adhere to the mandrels
during measurement of diameter, the mandrels may be coated with water 12.1.3 Maximum and minimum wall thickness for each
or talc as a lubricant. However, caution must be exercised not to force the
specimen in the expanded and in the recovered state,
tubing on the mandrel, thereby stretching the specimens.
12.1.4 Length of each specimen in the expanded and recov-
ered state,
11.1.2 Using a machinist’s micrometer, measure the outside
diameter of the mandrel to the nearest 0.001 in. (0.02 mm). 12.1.5 Percentage longitudinal change of each specimen
(after recovery) based on the expanded state length,
Record this as the expanded inside diameter.
11.1.3 Place the specimen in an oven at the temperature 12.1.6 Concentricity of each specimen in the expanded and
the recovered state, and
specifiedassuitableforcompleteshrinkageforaperiodoftime
recommended for shrinkage. Make provision for positioning 12.1.7 Time and temperature used for shrinkage of the
tubing.
the specimen horizontally in the oven so that recovery can be
effected without restriction. If the tubing tends to become
13. Precision and Bias
sticky at the shrinkage temperature, specimens can be laid in
trays that have been powdered slightly with talc.
13.1 The overall estimates of the precision within laborato-
11.1.4 At the end of the specified shrinkage time, remove
ries, (S ) j, and the precision between laboratories, (S )j, are
r r
the specimens from the oven and allow to cool to room
giveninTable1forfourselectedmaterials.Theseestimatesare
temperature. Measure the inside diameter as described in
based on a round robin of three specimens, each run in six
11.1.1 and 11.1.2, recording this as the recovered inside
laboratories. No bias statement can be made due to the lack of
diameter.
a standard reference material.
11.2 Measuring Wall Thickness:
11.2.1 Measure the wall thickness of the expanded (as RESTRICTED SHRINKAGE
supplied) tubing using a micrometer. By means of a sufficient
14. Significance and Use
number of tests, locate the points on the wall corresponding to
the minimum and the maximum wall thickness, and record
14.1 Thistestmethodcoversthedeterminationoftheability
these measurements to the nearest 0.001 in. (0.02 mm).
of heat-shrinkable tubing to be shrunk on a specially designed
11.2.2 Allow the specimens to recover under heat as de-
mandrel without splitting or cracking. A voltage proof test is
scribed in 11.1.3 and 11.1.4. Measure the wall thickness as
used to ascertain splitting or cracking.
described in 11.2.1 recording these as the recovered thick-
nesses.
11.3 Calculating Conc
...