1、Designation: D2148 13Standard Test Methods forBondable Silicone Rubber Tapes Used for ElectricalInsulation1This standard is issued under the fixed designation D2148; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 These test methods cover tests for bondable siliconerubber tapes which form a sealed structure either with theapplication
3、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 39Bond Strength 1017Dielectric Breakdown Voltage 1825Hardness 40Length 32 and 33Thickness 2631Width 35391.3 The values stated in inch-pound un
4、its are to be regardedas standard, except for C. The values in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is the
5、responsibility of the user of 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:2D149 Test Method for Dielectric Breakdown Vo
6、ltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD374 Test Methods for Thickness of Solid Electrical Insu-lation (Withdrawn 2013)3D1000 Test Methods for Pressure-Sensitive Adhesive-Coated Tapes Used for Electrical and Electronic Applica-tionsD1458 T
7、est Methods for Fully Cured Silicone Rubber-Coated Glass Fabric and Tapes for Electrical InsulationD2240 Test Method for Rubber PropertyDurometer Hard-nessD6054 Practice for Conditioning Electrical Insulating Mate-rials for Testing (Withdrawn 2012)32.2 ASTM Adjuncts:Tack tester (one drawing)4ADHESIO
8、N3. Scope3.1 This test method covers the determination of the 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 Us
9、e4.1 Self-adhesion is a primary initial property since it affectslayer-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
10、degree of self-adhesion is desirable for mostelectrical applications. 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 Fixture A suggested f
11、ix-ture is shown in Fig. 1.4The mandrel shall consist of a58-in.1These 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
12、 Nov. 1, 2013. Published November 2013. Originallyapproved in 1963. Last previous edition approved in 2008 as D2148 02 (2008)1.DOI: 10.1520/D2148-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStanda
13、rds volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from ASTM International Headquarters. Order Adjunct No.ADJD2148. Original adjunct produced in 1965.*A Summary of Chan
14、ges section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1(15.9-mm) diameter aluminum rod mounted in low-frictionbearings. Good alignment of bearings is necessary for accurateresults. When properly
15、 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 Specimen6.1 A test specimen shall consist of two pieces of tape 12 t
16、o15 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 contaminationshall be avoided.7. Procedure7.1 WindingHalf lap the un
17、marked 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 half lapping, tilt the tack tester at anappropriate angle as
18、 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 weight attached, return the testfixture to a horizontal po
19、sition 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) of the original tape width(Note 2).Attach the weight to t
20、he 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 division as one unit. While thewinding weights are not criti
21、cal, 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) tolerance. Therefore a 600-g weight shall be used for tapes vary
22、ingin 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 to1916 in. (36.5 to 39.7 mm). Tapes with widths outside these ranges shall betested in
23、 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 following information:8.1.1 Description of material, type of cross
24、-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 has been presented to ASTM upon which to basea statement of
25、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 Specific to This Standard:10.1.1 bond strength, of unvulcani
26、zed and semivulcanizedsupported silicone rubber tapesthe strength of chemicallinkages achieved between successive layers of tape undercontrolled vulcanizing conditions.FIG. 1 Inclined Mandrel Tack Test FixtureTABLE 1 Suggested Winding Weights For 1-in. Wide TapesNOTE 1Winding weights are based on cr
27、oss-sectional area and havebeen selected to produce 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
28、) 10.5 (300)0.030 (0.76) 0.015 (0.38) 15.8 (450)0.040 (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)D2148 13211. Significance and Use11.1 The bond strength is an indication of the physicalinte
29、grity that can be expected under end use conditions inwhich the insulating tapes are applied with an overlap.12. Apparatus12.1 Bonding PressA platen press having the followingcharacteristics:12.1.1 A temperature range to 205 C (400 F).12.1.2 A thermostat that will allow a set temperature to bemainta
30、ined 6 5C(6 9 F).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 ispreferred that a controller-type timer be used which will b
31、othindicate 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, approximately18 in. (3.20 mm)thick, 60 to 70 Shore A duromet
32、er 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, threesheets, approximately 2 to 4 mils (0.05 to 0.10 mm) thick.
33、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. Themachine shall be equipped with a tension weighing d
34、evicehaving 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 besufficient to give six strips at least 1.25 to 1.5 in. (3
35、2 to 38 mm)wide and 6 in. (150 mm) long. Care shall be taken to preventcontamination.14. Conditioning14.1 The specimen shall not be exposed to temperaturesabove 30 C (85 F) before bonding. The tests shall beconducted in the Standard LaboratoryAtmosphere as describedin Practice D6054.15. Procedure15.
36、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 another, front side to backside, to form a specimen.15.4 Sepa
37、rate 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 177 C (350 F).15.6 Assemble the test specimens between two sheets ofrelease film. Place the assembly on the unheated siliconerubber pad and insert in the press.15.7 Close
38、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 Clamp one separated end in the upper jaw of thetesting m
39、achine; 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. Record the averageobserved force for each specimen usi
40、ng the technique de-scribed for adhesion strength in Test Methods D1000.16. 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 time, pressure, and temperature used, ifother than as speci
41、fied.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 method has no bias because the value forbond strength is de
42、termined 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 electrical insulation.18.2 The method to be used for rectan
43、gular cross sectiontapes is described in Test Methods D1458.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 test is one measure of the quality of both materialand fab
44、rication methods used in producing the tape. It is notappropriate to make direct comparisons between this voltageD2148 133value and the results of tests made on rectangular cross sectiontapes. For further details, refer to Test Method D149.20. Apparatus20.1 Test Fixture, It shall be designed to supp
45、ort a remov-able mandrel18 in. (15.9 mm) in diameter and about (20 in.)(500 mm) in length. One example of the type of fixture is amodification of the one described in 5.1.20.2 Voltage Source, capable of applying alternating voltageand increasing it at the rate of 500 V/s. This equipment shallconform
46、 to the requirements of Test Method D149.21. 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 winding.
47、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 windi
48、ng 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. For example, inevaluating 0.030-in. (0.75-mm)
49、 tapes, three electrodes shall beplaced on a 20-in. (500-mm) long mandrel.21.3.1 If thicker tapes, which require higher voltage tofailure, are tested, they will often require more distancebetween electrodes in order to avoid flashover.21.3.2 Intimate contact between electrodes and tape surfaceis required for accurate results. Hand-tightening the foil isordinarily adequate.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 b
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