1、Designation: D 2148 02e1An American National StandardStandard Test Methods forBondable Silicone Rubber Tapes Used for ElectricalInsulation1This standard is issued under the fixed designation D 2148; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEAdjunct references were corrected editorially in April 2006.1. Scope1.1 These test methods cove
3、r tests for bondable siliconerubber tapes which form a sealed structure either with theapplication of heat (and pressure if needed) or by the processof auto-adhesion (self-fusing).1.2 The methods appear in the following sections:Test Method SectionAdhesion 3-9Bond Strength 10-17Dielectric Breakdown
4、Voltage 18-25Hardness 40Length 32 and 33Thickness 26-31Width 35-391.3 The values stated in inch-pound units are to be regardedas the standard except for C.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of
5、this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For a specifichazard statement see 22.1.1.2. Referenced Documents2.1 ASTM Standards:2D 149 Test Method for Dielectric Breakdown Voltage andDielectric Strength
6、of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD 374 Test Methods for Thickness of Solid Electrical Insu-lationD 1000 Test Methods for Pressure-Sensitive Adhesive-Coated Tapes Used for Electrical and Electronic Applica-tionsD 1458 Test Methods for Fully Cured Silicone Rubber-
7、Coated Glass Fabric and Tapes for Electrical InsulationD 2240 Test Method for Rubber PropertyDurometerHardnessD 6054 Practice for Conditioning Electrical Insulating Ma-terials for Testing2.2 ASTM Adjuncts:Tack tester (one drawing)3ADHESION3. Scope3.1 This test method covers the determination of the
8、self-adhesion of unsupported, self-fusing silicone rubber rectangu-lar and taper-edge (Note 1) tape designed for use as electricalinsulation.NOTE 1Taper-edge tape includes such cross sections as triangular,lens, etc.4. Significance and Use4.1 Self-adhesion is a primary initial property since it affe
9、ctslayer-to-layer bonding. The integrity of the bond can signifi-cantly affect the electrical and physical performance of theinsulation system. Therefore, the degree of self-adhesion isdirectly related to apparatus performance.4.2 A high degree of self-adhesion is desirable for mostelectrical applic
10、ations. In this test, a short unwinding lengthindicates a high degree of self-adhesion.4.3 This test method has been found useful as a qualitycontrol test for lot acceptance.5. Apparatus5.1 Inclined Mandrel Tack Test FixtureA suggested fix-ture is shown in Fig. 1.3The mandrel shall consist of a58-in
11、.(15.9-mm) diameter aluminum rod mounted in low-friction1These 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 Insulating Materials.Current edition approved March 1
12、0, 2002. Published June 2002. Originallyapproved in 1963. Last previous edition approved in 1995 as D 2148 95.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the st
13、andards Document Summary page onthe ASTM website.3Available from ASTM International Headquarters. Order Adjunct No.ADJD2148. Original adjunct produced in 1965.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.bearings. Good alignment o
14、f bearings is necessary for accurateresults. When properly assembled, the mandrel shall turn freelywhen loaded with a 1-oz (30-g) weight suspended from acotton thread wound in a single layer at the center of themandrel.5.2 Weights, as specified in Section 7 and means forattachment.6. Test Specimen6.
15、1 A test specimen shall consist of two pieces of tape 12 to15 in. (300 to 380 mm) long. Divisions spaced 1 in. (25.4 mm)apart shall be marked off on one piece of tape. If tapes containan interliner, the interliner shall be removed just prior towrapping the mandrel. Dirt and other forms of contaminat
16、ionshall be avoided.7. Procedure7.1 WindingHalf lap the unmarked specimen perfectly onthe mandrel of the test fixture, using the suggested weight asshown in Table 1. These weights are not critical. However, theyare necessary to get intimate contact and conformability of thetape. To obtain perfect ha
17、lf lapping, tilt the tack tester at anappropriate angle as shown in Fig. 1. Wrap the tape on themandrel at a speed of approximately 18 in. (450 mm)/min.Using the winding procedure and weights just described, halflap the marked tape sample on the mandrel over the first pieceof tape. With the winding
18、weight attached, return the testfixture to a horizontal position and allow the tape to bond for1 min. Remove the winding weight from the tape and thehandle from the fixture and proceed with the unwinding test.7.2 UnwindingAfter the tape has bonded for 1 min, attacha load of 21 oz (600 g)/in. (25 mm)
19、 of the original tape width(Note 2).Attach the weight to the free end of the tape by meansof a bulldog paper clamp or other suitable device. Release theweight and record the length of tape unwound in 3 min.Although the original 1-in. dimensions will elongate due to theunwind weight, consider each di
20、vision as one unit. While thewinding weights are not critical, the use of proper unwindingweights is mandatory. Consistent and comparable results de-pend upon accurate width measurements and the use of theproper unwinding weight.NOTE 2Commercial tapes are usually made to a 6116-in. (61.59-mm) tolera
21、nce. Therefore a 600-g weight shall be used for tapes varyingin width from1516 to 1116 in. (23.8 to 27 mm); a 750-g weight shall beused for tapes varying in width from 1316 to 1516 in. (30.2 to 33.3 mm) anda 900-g weight shall be used for tapes varying in width from 1716 to 1916in. (36.5 to 39.7 mm)
22、. Tapes with widths outside these ranges shall betested in accordance with their width (determined to the nearest116 in.(1.59 mm). For example, a 118-in. (28.6 mm) wide tape shall be testedwith a 675-g weight. The unwinding weights shall be made to a toleranceof 6 2%.8. Report8.1 Report the followin
23、g information:8.1.1 Description of material, type of cross-section, tapewidth and thickness,8.1.2 Winding weight, in grams,8.1.3 Unwinding weight, in grams, and8.1.4 Length of unwind, to the nearest14 unit.9. Precision and Bias9.1 This test method has been in use for many years, but noinformation ha
24、s been presented to ASTM upon which to basea statement of precision. No activity has been planned todevelop such information.9.2 This test method has no bias because the value foradhesion is determined solely in terms of this test methoditself.BOND STRENGTH10. Terminology10.1 Definitions of Terms Sp
25、ecific to This Standard:10.1.1 bond strength, of unvulcanized and semivulcanizedsupported silicone rubber tapesthe strength of chemicallinkages achieved between successive layers of tape undercontrolled vulcanizing conditions.11. Significance and Use11.1 The bond strength is an indication of the phy
26、sicalintegrity that can be expected under end use conditions inwhich the insulating tapes are applied with an overlap.FIG. 1 Inclined Mandrel Tack Test FixtureTABLE 1 Suggested Winding Weights For 1-in. Wide TapesNOTE 1Winding weights are based on cross-sectional area and havebeen selected to produc
27、e approximately the same unit stress on allcross-sections. For tapes of dimensions not listed, use a winding weight ofapproximately 10.5 oz (300 g)/0.01 in.2(6.3 mm2)Tape Thickness, in. (mm)Weight, oz (g)Triangular Rectangular0.020 (0.51) 0.010 (0.25) 10.5 (300)0.030 (0.76) 0.015 (0.38) 15.8 (450)0.
28、040 (1.02) 0.020 (0.51) 21.0 (600)0.050 (1.27) 0.025 (0.64) 26.4 (750)0.060 (1.52) 0.030 (0.76) 31.7 (900)0.070 (1.78) . 37.0 (1050)0.080 (2.03) . 42.3 (1200)D214802e1212. Apparatus12.1 Bonding PressA platen press having the followingcharacteristics:12.1.1 A temperature range to 205C (400F).12.1.2 A
29、 thermostat that will allow a set temperature to bemaintained 69F (65C).12.1.3 A pressure regulator to allow setting and control ofthe platen pressure.12.1.4 A pressure indicator to show the pressure beingexerted between the platen faces.12.1.5 A timer to allow measurement of bonding time. It ispref
30、erred that a controller-type timer be used which will bothindicate bonding time and also cause the platen pressure to bereleased and the platens separated at the end of the bondingperiod.12.2 Temperature-Measuring Device(s) to indicate facetemperature of the platen(s).12.3 Silicone Rubber Pad, appro
31、ximately18 in. (3.20 mm)thick, 60 to 70 Shore A durometer hardness, larger in dimen-sion than the specimens to be tested. This is used as apressure-equalizing device, compensating for irregularities ineither the specimen or the platens.12.4 Polytetrafluoroethylene or suitable release film, threeshee
32、ts, approximately 2 to 4 mils (0.05 to 0.10 mm) thick. Onesheet is placed on each side of the specimens as a release sheet,the third sheet being used to separate the ends of the two testspecimens.12.5 Testing MachineA power-driven testing machine ofeither the cross head or dead-weight pendulum type.
33、 Themachine shall be equipped with a tension weighing devicehaving a maximum capacity of 50 lb (22.7 kg) graduated toread 0.1 lb (50 g) or less per scale division.13. Test Specimen13.1 The test specimen shall be selected to be representativeof the material to be tested. The size of sample shall besu
34、fficient to give six strips at least 1.25 to 1.5 in. (32 to 38 mm)wide and 6 in. (150 mm) long. Care should be taken to preventcontamination.14. Conditioning14.1 The specimen shall not be exposed to temperaturesabove 85F (30C) before bonding. The tests shall be con-ducted in the Standard Laboratory
35、Atmosphere as described inPractice D 6054.15. Procedure15.1 Cut the strips of material to 1.25 to 1.5 in. (32 to 38mm) wide and at least 6 in. (150 mm) long, the length beingmeasured in the warp or machine direction of the backing.15.2 Remove any interliner material.15.3 Superimpose one strip on ano
36、ther, front side to backside, to form a specimen.15.4 Separate the two strips at one end for a distance ofabout 1 in. (25 mm) and insert a strip of release film.15.5 Preheat the press to 177C (350F).15.6 Assemble the test specimens between two sheets ofrelease film. Place the assembly on the unheate
37、d siliconerubber pad and insert in the press.15.7 Close the press and apply 50 psi (345 kPa) pressure tothe specimens for 5 min.15.8 Release the pressure, remove the specimens, and allowthem to cool for at least 5 min.15.9 Remove the release film and trim the specimens to a1-in. (25-mm) width.15.10
38、Clamp one separated end in the upper jaw of thetesting machine; peel the other separated end back 180 deg andclamp it in the lower jaw.15.11 Adjust the testing machine to provide a jaw separationrate of 20 in. (500 mm) per min. If the pendulum-type machineis used, disengage the pawls during the test
39、. Record the averageobserved force for each specimen using the technique de-scribed for adhesion strength in Test Methods D 1000.16. Report16.1 Report the following information:16.1.1 Bond strength of each specimen and the average inpounds per inch or newtons per metre of width, and16.1.2 Bonding ti
40、me, pressure, and temperature used, ifother than as specified.17. Precision and Bias17.1 This test method has been in use for many years, but noinformation has been presented to ASTM upon which to basea statement of precision. No activity has been planned todevelop such information.17.2 This test me
41、thod has no bias because the value forbond strength is determined solely in terms of this test methoditself.DIELECTRIC BREAKDOWN VOLTAGE18. Scope18.1 This test method covers determination of the break-down voltage of unsupported bondable silicone rubber tapeswith tapered edges (Note 3) for use as el
42、ectrical insulation.18.2 The method to be used for rectangular cross sectiontapes is described in Test Methods D 1458.NOTE 3Tapes with tapered edges include such cross sections astriangular and lens-shaped.19. Significance and Use19.1 The level of dielectric breakdown voltage as deter-mined by this
43、test is one measure of the quality of both materialand fabrication methods used in producing the tape. Thisvoltage value should not be compared directly with the resultsof tests made on rectangular cross section tapes. For furtherdetails, refer to Test Method D 149.20. Apparatus20.1 Test Fixture, de
44、signed to support a removable mandrel18 in. (15.9 mm) in diameter and about (20 in.) (500 mm) inlength. This fixture may be a modification of the one describedin 5.1.20.2 Voltage Source, capable of applying alternating voltageand increasing it at the rate of 500 V/s. This equipment shallconform to t
45、he requirements of Test Method D 149.D214802e1321. Test Specimen21.1 The test specimen shall consist of lengths of bondabletape about 0.75 to 2 in. (19 to 50 mm) wide and of sufficientlength to cover the entire mandrel.21.2 Adjust the mandrel to such an angle as will provide ahalf-lapped tape on win
46、ding. Wrap the tape on the mandrel ata linear speed of 18 in.(450 mm)/min using the winding weightshown in Table 2.NOTE 4Winding weights are based on cross sectional area and havebeen selected to approximate the same unit stress for all cross sections.For tapes of dimensions other than listed, use a
47、 winding weight of about300 g/0.01 in.2(6.3 mm2).21.3 Apply foil electrodes 0.0005 to 0.002 in. (0.013 to0.050 mm) thick by 1 in. (25 mm) wide over the tapes,allowing approximately 4 in. (100 mm) between electrodes andfrom electrodes to the end of the mandrel (Note 5). Forexample, in evaluating 0.03
48、0-in. (0.75-mm) tapes, three elec-trodes shall be placed on a 20-in. (500-mm) long mandrel.Thicker tapes which require higher voltage to failure mayrequire more distance between electrodes in order to avoidflashover.NOTE 5Intimate contact between electrodes and tape surface isrequired for accurate r
49、esults. Hand-tightening the foil is ordinarilyadequate.22. Procedure22.1 Attach a high-voltage lead to one foil electrode andelectrically ground the mandrel. Increase the voltage starting atzero and at a rate of 500 V/s until breakdown occurs. Repeatthis procedure for all electrodes and record the breakdownvoltages. Obtain at least six breakdown values.22.1.1 WarningLethal voltages are a potential hazardduring the performance of this test. It is essential that the testapparatus, and all associated equipment electrically connectedto it, be properly
