ASTM D2671-00

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation:D2671–00
Standard Test Methods for
Heat-Shrinkable Tubing for Electrical Use
This standard is issued under the fixed designation D 2671; 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 (e) 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 1—These test methods are similar, but not identical to, those in
1. Scope
IEC 60684–2 (see also Note 9).
1.1 These test methods cover the testing of heat-shrinkable
tubing used for electrical insulation. Materials used include
2. Referenced Documents
poly(vinyl chloride), polyolefins, fluorocarbon polymers, sili-
2.1 ASTM Standards:
cone rubber, and other plastic or elastomeric compounds.
D 149 Test Method for Dielectric Breakdown Voltage and
1.2 The values stated in inch-pound units are the standard
Dielectric Strength of Solid Electrical Insulating Materials
except for temperature, which shall be expressed in degrees
at Commercial Power Frequencies
Celsius. Values stated in parentheses are for information only.
D 257 Test Methods for D-C Resistance or Conductance of
1.3 The procedures appear in the following sections:
Insulating Materials
ASTM Method
D 412 Test Methods for Vulcanized Rubber and Thermo-
Procedure Sections Reference
plastic Rubbers and Thermoplastic Elastomers—Tension
Adhesive Peel Strength 98 to 104
Brittleness Temperature 40 D 746
D 570 Test Method for Water Absorption of Plastics
Color 55 to 56 D 1535
D 618 Practice for Conditioning Plastics and Electrical
Color Stability 57 to 62 D 1535
Insulating Materials for Testing
Conditioning 7 D 618
Copper Stability 93
D 746 Test Method for Brittleness Temperature of Plastics
Corrosion Testing 89 to 95 4
and Elastomers by Impact
Dielectric Breakdown 20 to 25 D 149
D 792 TestMethodsforDensityandSpecificGravity(Rela-
Dimensions 8 to 13 D 876
Flammability 68 to 72 D 876
tive Density) of Plastics by Displacement
Fluid Resistance 63 to 67
D 876 Test Methods for Nonrigid Vinyl Chloride Polymer
Fungus Resistance 104 to 108
Tubing Used for Electrical Insulation
Heat Resistance 49 to 54
Heat Shock 26 to 30
D 882 Test Methods for Tensile Properties of Thin Plastic
Low-Temperature Properties 36 to 43
Sheeting
Restricted Shrinkage 14 to 19
D 1535 Practice for Specifying Color by the Munsell Sys-
Selection of Test Specimens 6
Secant Modulus 81 to 84 D 882
tem
Storage Life 31 to 35
D 1711 Terminology Relating to Electrical Insulation
Specific Gravity 73 to 74 D 792
D 3418 Test Method for Transition Temperatures of Poly-
Stress Modulus 85 to 88 D 412
Tensile Strength and Ultimate Elongation 44 to 48 D 412
mers by Thermal Analysis
Thermal Endurance 96 to 97
E 176 Terminology of Fire Standards
Volume Resistivity 75 to 78 D 257
2.2 Other Documents:
Water Absorption 79 to 80 D 570
Melting Point 104 to 108 D 3418
MIL-STD 104 Limits for Electrical Insulation Color
IEC Publication 216 Guide for the Determination of
1.4 This is a fire-test-response standard.
Thermal Endurance Properties of Electrical Insulating
1.5 This standard does not purport to address all of the
Materials
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
Annual Book of ASTM Standards, Vol 10.01.
bility of regulatory limitations prior to use. For specific hazard
Annual Book of ASTM Standards, Vol 09.01.
statements, see Sections 5 and 68.2. 4
Annual Book of ASTM Standards, Vol 08.01.
Annual Book of ASTM Standards, Vol 06.01.
Annual Book of ASTM Standards, Vol 08.02.
1 7
These test methods are under the jurisdiction of ASTM Committee D09 on Annual Book of ASTM Standards, Vol 04.07.
Electrical and Electronic Insulating Materials and are the direct responsibility of AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
Subcommittee D09.07 on Flexible and Rigid Insulating Materials. Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Current edition approved Apr. 10, 2000. Published May 2000. Originally Available from American National Standards Institute, 11 W. 42nd St., 13th
published as D 2671 – 67 T. Last previous edition D 2671 – 99. Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2671–00
IECPublication60684 SpecificationforFlexibleInsulating 5. Hazards
Sleeving
5.1 Warning— Lethal voltages may be present during this
ISO 846 Plastics—Evaluation of theAction of Microorgan-
test. It is essential that the test apparatus, and all associated
isms
equipment that may be electrically connected to it, be properly
designed and installed for safe operation. Solidly ground all
3. Terminology
electrically conductive parts that any person might come in
contact with during the test. Provide means for use at the
3.1 Definitions:
completion of any test to ground any parts which: were at high
3.1.1 For definitions pertaining to electrical insulation, refer
voltage during the test; may have acquired an induced charge
to Terminology D 1711.
during the test; may retain a charge even after disconnection of
3.1.2 For definitions pertaining to fire standards, refer to
the voltage source. Thoroughly instruct all operators in the
Terminology E 176.
proper way to conduct tests safely. When making high voltage
3.1.3 heat-shrinkable tubing, n—tubing that will reduce in
tests, particularly in compressed gas or in oil, the energy
diameter from an expanded size to a predetermined size by the
released at breakdown may be suffıcient to result in fire,
application of heat.
explosion, or rupture of the test chamber. Design test equip-
3.2 Definitions of Terms Specific to This Standard:
ment, test chambers, and test specimens so as to minimize the
3.2.1 brittleness temperature, n—the temperature at which
possibility of such occurrences and to eliminate the possibility
50 % of the specimens fail when the specified number are
of personal injury. (See Section 23.)
tested using the apparatus and conditions specified.
5.2 Flammable Solvents:
3.2.2 concentricity, n—the ratio expressed in percent of the
5.2.1 Methylethylketoneisavolatile,flammablesolvent.It
minimum wall thickness to the maximum wall thickness.
should be handled in an area having good ventilation, such as
3.2.3 longitudinal change, n—the change in length, either a laboratory hood and away from sources of ignition. See
positive or negative, that occurs when the tubing is allowed to Section 100.
freely recover at the recommended recovery temperature,
6. Selection of Test Specimens
expressed as a percentage of the as supplied or expanded
length. 6.1 Select a sufficient number of pieces of tubing in such
manner as to be representative of the shipment.
3.2.4 low-temperature flexibility, n—the resistance to crack-
6.2 Cut specimens, free of kinks, from the sample selected
ing of tubing when wrapped around prescribed mandrels at
under 6.1. Cut perpendicular to the longitudinal axis of the
specified temperatures.
tubing and in such manner that the specimen has cleanly cut
3.2.5 restricted shrinkage, n—shrinkage of the tubing at a
square edges.
prescribed temperature over a specially designed mandrel
6.3 Unless otherwise stated, test specimens in the com-
whose smallest diameter is greater than the fully shrunk size
pletely shrunk condition.
andwhoselargestdiameterislessthantheexpandedsizeofthe
tubing.
7. Conditioning
3.2.6 storage-life, heat-shrinkable tubing, n—the length of
7.1 When specified, condition tubing in accordance with
time that the tubing will retain its specified expanded and
Practice D 618 using Procedure A, except use a conditioning
recovered dimensions under storage at a specified temperature.
time of 4 h. In cases where tests are performed on specimens
in the shrunk state, condition prior to testing, but after heat
4. Significance and Use
shrinking.
4.1 These test methods include most of the important tests
DIMENSIONS
used to characterize heat-shrinkable tubing. They are intended
primarily for, but not limited to, extruded heat-shrinkable
8. Significance and Use
tubing.
8.1 Inside Diameter—The inside diameter of tubing before
4.2 Variations in these test methods or alternate contempo-
and after heat-shrinking is an important factor in selecting
rary methods of measurement may be used to determine the
tubing of the proper size to slip easily over an object and to
values for the properties in this standard provided such
conform tightly after shrinkage.
methodsensurequalitylevelsandmeasurementaccuracyequal
8.2 Wall Thickness—Wall thickness measurements are use-
to or better than those prescribed herein. It is the responsibility
ful in providing design data and in calculating certain physical
of the organizations using alternate test methods to be able to
and electrical properties of the tubing.
demonstrate this condition. In cases of dispute, the methods
8.3 Concentricity—A thin wall area, due to variation in
specified herein shall be used.
processing, may lead to equipment failure. It is important,
NOTE 2—Provision for alternate methods is necessary because of (1)
therefore, both in extrusion of the tubing, and its expansion
the desire to simplify procedures for specific applications without altering
prior to shrinkage in end-use, that concentricity be held above
the result, and (2) the desire to eliminate redundant testing and use data
a specified limit to ensure proper performance of the tubing.
generated during manufacturing process control, including that generated
8.4 Length—The length, both before and after heat-
under Statistical Process Control (SPC) conditions, using equipment and
shrinking, is important in the determination of proper fit of the
methods other than those specified herein. An example would be the use
of laser micrometers or optical comparators to measure dimensions. tubing in end-use.
D2671–00
9. Apparatus
M 9 = minimum thickness, in. (mm).
11.4 Measuring Length:
9.1 Mandrels—A series of steel rods suitable for insertion
into the tubing including the tapered gages described under 11.4.1 Using the steel scale, measure the length to the
nearest ⁄32 in. or 1 mm.
Test Methods D 876, 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 65°C.
dance with 11.4.1 and 11.4.2, calculate the percent longitudinal
10. Test Specimens
change using the following equation:
10.1 Cut three straight lengths of expanded tubing, each 6
Percent longitudinal change 5 100 ~L8 2 L9!/L9 (2)
in. (150 mm) long, from the sample as directed in 6.2 for each
where:
test performed.
L8 = recovered length, in. (mm), and
11. Procedure
L9 = expanded length, in. (mm).
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
NOTE 3—Should the tubing specimens tend to adhere to the mandrels
the recovered state,
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-
11.1.2 Using a machinist’s micrometer, measure the outside
ered state,
diameter of the mandrel to the nearest 0.001 in. (0.02 mm).
12.1.5 Percentage longitudinal change of each specimen
Record this as the expanded inside diameter.
(after recovery) based on the expanded state length,
11.1.3 Place the specimen in an oven at the temperature
12.1.6 Concentricity of each specimen in the expanded and
specifiedassuitableforcompleteshrinkageforaperiodoftime
the recovered state, and
recommended for shrinkage. Make provision for positioning
12.1.7 Time and temperature used for shrinkage of the
the specimen horizontally in the oven so that recovery can be
tubing.
effected without restriction. If the tubing tends to become
sticky at the shrinkage temperature, specimens can be laid in
13. Precision and Bias
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
diameter.
of 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
number of tests, locate the points on the wall corresponding to
14. Significance and Use
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.
15. Apparatus
11.3 Calculating Concentricity—From measurements of
15.1 Mandrels—A series of mandrels having the dimen-
minimum and maximum wall thickness made in accordance
sions shown in Fig. 1 and Table 2. Care shall be taken that all
with 11.2.1 and 11.2.2, calculate the concentricity (C) of the
sharp edges are deburred.
expanded and reco
...