1、Designation: D2671 09An American National StandardStandard Test Methods forHeat-Shrinkable Tubing for Electrical Use1This standard is issued under the fixed designation D2671; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript 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.1. Scope*1.1 These test methods cover the te
3、sting of heat-shrinkabletubing used for electrical insulation. Materials used includepoly(vinyl chloride), polyolefins, fluorocarbon polymers, sili-cone rubber, and other plastic or elastomeric compounds.1.2 The values stated in inch-pound units are to be regardedas standard, except for temperature,
4、 which shall be expressedin degrees Celsius. The values given in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard.1.3 The procedures appear in the following sections:Procedure SectionsASTM MethodReferenceAdhesive Peel Strength
5、98-104Brittleness Temperature 40 D746Color 55 and 56 D1535Color Stability 57-62 D1535Conditioning 7 D618Copper Stability 93Corrosion Testing 89-95Dielectric Breakdown 20-25 D149Dimensions 8-13 D876Flammability 68-72 D876Fluid Resistance 63-67Fungus Resistance 104-108Heat Resistance 49-54Heat Shock 2
6、6-30Low-Temperature Properties 36-43Restricted Shrinkage 14-19Selection of Test Specimens 6Secant Modulus 81-84 D882Storage Life 31-35Specific Gravity 73 and 74 D792Stress Modulus 85-88 D412Tensile Strength and Ultimate Elongation 44-48 D412Thermal Endurance 96 and 97Volume Resistivity 75-78 D257Wat
7、er Absorption 79 and 80 D570Melting Point 104-108 D34181.4 This is a fire-test-response standard.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health
8、practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see Sections 5 and 68.2.NOTE 1These test methods are similar, but not identical to, those inIEC 606842 (see also Note 9).2. Referenced Documents2.1 ASTM Standards:2D149 Test Method for D
9、ielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD257 Test Methods for DC Resistance or Conductance ofInsulating MaterialsD412 Test Methods for Vulcanized Rubber and Thermo-plastic ElastomersTensionD570 Test Method for Water Ab
10、sorption of PlasticsD618 Practice for Conditioning Plastics for TestingD746 Test Method for Brittleness Temperature of Plasticsand Elastomers by ImpactD792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD876 Test Methods for Nonrigid Vinyl Chloride Polym
11、erTubing Used for Electrical InsulationD882 Test Method for Tensile Properties of Thin PlasticSheetingD1535 Practice for Specifying Color by the Munsell SystemD1711 Terminology Relating to Electrical InsulationD3418 Test Method for Transition Temperatures and En-thalpies of Fusion and Crystallizatio
12、n of Polymers byDifferential Scanning CalorimetryE176 Terminology of Fire Standards2.2 Other Documents:1These test methods are under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and are the direct responsibility ofSubcommittee D09.07 on Flexible and Rigid I
13、nsulating Materials.Current edition approved Oct. 1, 2009. Published November 2009. Originallyapproved in 1967. Last previous edition approved in 2007 as D2671 00(2007)1.DOI: 10.1520/D2671-09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser
14、viceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*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, Un
15、ited States.MIL-STD 104 Limits for Electrical Insulation Color3IEC Publication 216 Guide for the Determination ofThermal Endurance Properties of Electrical InsulatingMaterials4IEC Publication 60684 Specification for Flexible InsulatingSleeving4ISO 846 PlasticsEvaluation of the Action of Microorgan-i
16、sms43. Terminology3.1 Definitions:3.1.1 For definitions pertaining to electrical insulation, referto Terminology D1711.3.1.2 For definitions pertaining to fire standards, refer toTerminology E176.3.1.3 heat-shrinkable tubing, ntubing that will reduce indiameter from an expanded size to a predetermin
17、ed size by theapplication of heat.3.2 Definitions of Terms Specific to This Standard:3.2.1 brittleness temperature, nthe temperature at which50 % of the specimens fail when the specified number aretested using the apparatus and conditions specified.3.2.2 concentricity, nthe ratio expressed in percen
18、t of theminimum wall thickness to the maximum wall thickness.3.2.3 longitudinal change, nthe change in length, eitherpositive or negative, that occurs when the tubing is allowed tofreely recover at the recommended recovery temperature,expressed as a percentage of the as supplied or expandedlength.3.
19、2.4 low-temperature flexibility, nthe resistance to crack-ing of tubing when wrapped around prescribed mandrels atspecified temperatures.3.2.5 restricted shrinkage, nshrinkage of the tubing at aprescribed temperature over a specially designed mandrelwhose smallest diameter is greater than the fully
20、shrunk sizeand whose largest diameter is less than the expanded size of thetubing.3.2.6 storage-life, heat-shrinkable tubing, nthe length oftime that the tubing will retain its specified expanded andrecovered dimensions under storage at a specified temperature.4. Significance and Use4.1 These test m
21、ethods include most of the important testsused to characterize heat-shrinkable tubing. They are intendedprimarily for, but not limited to, extruded heat-shrinkabletubing.4.2 Variations in these test methods or alternate contempo-rary methods of measurement may be used to determine thevalues for the
22、properties in this standard provided suchmethods ensure quality levels and measurement accuracy equalto or better than those prescribed herein. It is the responsibilityof the organizations using alternate test methods to be able todemonstrate this condition. In cases of dispute, the methodsspecified
23、 herein shall be used.NOTE 2Provision for alternate methods is necessary because of (1)the desire to simplify procedures for specific applications without alteringthe result, and (2) the desire to eliminate redundant testing and use datagenerated during manufacturing process control, including that
24、generatedunder Statistical Process Control (SPC) conditions, using equipment andmethods other than those specified herein. An example would be the useof laser micrometers or optical comparators to measure dimensions.5. Hazards5.1 Warning Lethal voltages may be present during thistest. It is essentia
25、l that the test apparatus, and all associatedequipment that may be electrically connected to it, be properlydesigned and installed for safe operation. Solidly ground allelectrically conductive parts that any person might come incontact with during the test. Provide means for use at thecompletion of
26、any test to ground any parts which: were at highvoltage during the test; may have acquired an induced chargeduring the test; may retain a charge even after disconnection ofthe voltage source. Thoroughly instruct all operators in theproper way to conduct tests safely. When making high voltagetests, p
27、articularly in compressed gas or in oil, the energyreleased at breakdown may be suffcient to result in fire,explosion, or rupture of the test chamber. Design test equip-ment, test chambers, and test specimens so as to minimize thepossibility of such occurrences and to eliminate the possibilityof per
28、sonal injury. (See Section 23.)5.2 Flammable Solvents:5.2.1 Methyl ethyl ketone is a volatile, flammable solvent. Itshould be handled in an area having good ventilation, such asa laboratory hood and away from sources of ignition. SeeSection 100.6. Selection of Test Specimens6.1 Select a sufficient n
29、umber of pieces of tubing in suchmanner as to be representative of the shipment.6.2 Cut specimens, free of kinks, from the sample selectedunder 6.1. Cut perpendicular to the longitudinal axis of thetubing and in such manner that the specimen has cleanly cutsquare edges.6.3 Unless otherwise stated, t
30、est specimens in the com-pletely shrunk condition.7. Conditioning7.1 When specified, condition tubing in accordance withPractice D618 using Procedure A, except use a conditioningtime of 4 h. In cases where tests are performed on specimensin the shrunk state, condition prior to testing, but after hea
31、tshrinking.DIMENSIONS8. Significance and Use8.1 Inside DiameterThe inside diameter of tubing beforeand after heat-shrinking is an important factor in selectingtubing of the proper size to slip easily over an object and toconform tightly after shrinkage.8.2 Wall ThicknessWall thickness measurements a
32、re use-ful in providing design data and in calculating certain physicaland electrical properties of the tubing.3Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.4Available from American National Standards Institute (ANS
33、I), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.D2671 0928.3 ConcentricityA thin wall area, due to variation inprocessing, may lead to equipment failure. It is important,therefore, both in extrusion of the tubing, and its expansionprior to shrinkage in end-use, that concentricit
34、y be held abovea specified limit to ensure proper performance of the tubing.8.4 LengthThe length, both before and after heat-shrinking, is important in the determination of proper fit of thetubing in end-use.9. Apparatus9.1 MandrelsA series of steel rods suitable for insertioninto the tubing includi
35、ng the tapered gages described underTest Methods D876, may be used.9.2 Micrometers, mandrel anvil and indicator set accurate toat least 0.001 in. or 0.02 mm.9.3 Steel Scale, graduated in164-in. or 0.5-mm divisions.9.4 Oven, forced-convection type, capable of maintainingtemperature to within 6 5 C.10
36、. Test Specimens10.1 Cut three straight lengths of expanded tubing, each 6in. (150 mm) long, from the sample as directed in 6.2 for eachtest performed.11. Procedure11.1 Measuring Inside Diameter:11.1.1 Select a mandrel that will just fit into the specimenand insert the mandrel into the expanded tubi
37、ng for a distanceof 1 in. (25 mm).NOTE 3Should the tubing specimens tend to adhere to the mandrelsduring measurement of diameter, the mandrels may be coated with wateror talc as a lubricant. However, caution must be exercised not to force thetubing on the mandrel, thereby stretching the specimens.11
38、.1.2 Using a machinists micrometer, measure the outsidediameter of the mandrel to the nearest 0.001 in. (0.02 mm).Record this as the expanded inside diameter.11.1.3 Place the specimen in an oven at the temperaturespecified as suitable for complete shrinkage for a period of timerecommended for shrink
39、age. Make provision for positioningthe specimen horizontally in the oven so that recovery can beeffected without restriction. If the tubing tends to becomesticky at the shrinkage temperature, specimens can be laid intrays that have been powdered slightly with talc.11.1.4 At the end of the specified
40、shrinkage time, removethe specimens from the oven and allow to cool to roomtemperature. Measure the inside diameter as described in11.1.1 and 11.1.2, recording this as the recovered insidediameter.11.2 Measuring Wall Thickness:11.2.1 Measure the wall thickness of the expanded (assupplied) tubing usi
41、ng a micrometer. By means of a sufficientnumber of tests, locate the points on the wall corresponding tothe minimum and the maximum wall thickness, and recordthese measurements to the nearest 0.001 in. (0.02 mm).11.2.2 Allow the specimens to recover under heat as de-scribed in 11.1.3 and 11.1.4. Mea
42、sure the wall thickness asdescribed in 11.2.1 recording these as the recovered thick-nesses.11.3 Calculating ConcentricityFrom measurements ofminimum and maximum wall thickness made in accordancewith 11.2.1 and 11.2.2, calculate the concentricity (C) of theexpanded and recovered tubing respectively,
43、 using the follow-ing equation:C 5 100 M9/M8! (1)where:M8 = maximum thickness, in. (mm), andM 9 = minimum thickness, in. (mm).11.4 Measuring Length:11.4.1 Using the steel scale, measure the length to thenearest132 in. or 1 mm.11.4.2 Allow the specimens to recover under heat as de-scribed in 11.1.3 a
44、nd 11.1.4. Measure the length after recovery.Record the length in the expanded and recovered state.11.5 Calculating Longitudinal Change From the mea-surements of expanded and recovered length made in accor-dance with 11.4.1 and 11.4.2, calculate the percent longitudinalchange using the following equ
45、ation:Percent longitudinal change 5 100 L8 2 L9!/L9 (2)where:L8 = recovered length, in. (mm), andL9 = expanded length, in. (mm).12. Report12.1 Report the following information:12.1.1 Identification of the tubing,12.1.2 Inside diameter of the tubing in the expanded and inthe recovered state,12.1.3 Ma
46、ximum and minimum wall thickness for eachspecimen in the expanded and in the recovered state,12.1.4 Length of each specimen in the expanded and recov-ered state,12.1.5 Percentage longitudinal change of each specimen(after recovery) based on the expanded state length,12.1.6 Concentricity of each spec
47、imen in the expanded andthe recovered state, and12.1.7 Time and temperature used for shrinkage of thetubing.13. Precision and Bias13.1 The overall estimates of the precision within laborato-ries, (Sr) j, and the precision between laboratories, (Sr)j, aregiven in Table 1 for four selected materials.
48、These estimates arebased on a round robin of three specimens, each run in sixlaboratories.5No bias statement can be made due to the lack ofa standard reference material.RESTRICTED SHRINKAGE14. Significance and Use14.1 This test method covers the determination of the abilityof heat-shrinkable tubing
49、to be shrunk on a specially designed5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D09-1017.D2671 093mandrel without splitting or cracking. A voltage proof test isused to ascertain splitting or cracking.15. Apparatus15.1 MandrelsA series of mandrels having the dimen-sions shown in Fig. 1 and Table 2. Care shall be taken that allsharp edges are deburred.15.2 Oven, forced-convection type, capable of maintainingtemperature to within 6 5 C as described in 9.4.16. Test Specimens16.
