1、Designation: D 1458 01 (Reapproved 2007)An American National StandardStandard Test Methods forFully Cured Silicone Rubber-Coated Glass Fabric and Tapesfor Electrical Insulation1This standard is issued under the fixed designation D 1458; the number immediately following the designation indicates the
2、year oforiginal adoption or, in the case 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.This standard has been approved for use by agencies of the Depa
3、rtment of Defense.1. Scope1.1 These test methods cover procedures for testing fullycured silicone rubber-coated glass fabric and tapes to be usedfor electrical insulation.1.2 The procedures appear in the following order:Procedure SectionsASTMReferencesBreaking Strength 7 D 828Breaking Strength After
4、 Creasing 8 .Conditioning 5 .Dielectric Breakdown Voltage 9 D 149, D 295,D 6054Dielectric Proof-Voltage 10 D 1389Dissipation Factor and Relative Permittivity 11 D 150Sampling 4 .Thermal Endurance 15 D 1830Thickness 6 D 374Thread Count 14 .Volume Resistivity 12 D 257Weight 13 .1.3 The values stated i
5、n inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.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 this standard to establish appro-priate safet
6、y and health practices and determine the applica-bility of regulatory limitations prior to use. See 9.5.1 for aspecific warning statement.2. Referenced Documents2.1 ASTM Standards:2D 149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Co
7、mmercial Power FrequenciesD 150 Test Methods for AC Loss Characteristics and Per-mittivity (Dielectric Constant) of Solid Electrical Insula-tionD 202 Test Methods for Sampling and Testing UntreatedPaper Used for Electrical InsulationD 257 Test Methods for DC Resistance or Conductance ofInsulating Ma
8、terialsD 295 Test Methods for Varnished Cotton Fabrics Used forElectrical InsulationD 374 Test Methods for Thickness of Solid Electrical Insu-lationD 828 Test Method for Tensile Properties of Paper andPaperboard Using Constant-Rate-of-Elongation ApparatusD 1389 Test Method for Proof-Voltage Testing
9、of ThinSolid Electrical Insulating MaterialsD 1711 Terminology Relating to Electrical InsulationD 1830 Test Method for Thermal Endurance of FlexibleSheet Materials Used for Electrical Insulation by theCurved Electrode MethodD 5032 Practice for Maintaining Constant Relative Humid-ity by Means of Aque
10、ous Glycerin SolutionsD 6054 Practice for Conditioning Electrical Insulating Ma-terials for TestingE 104 Practice for Maintaining Constant Relative Humidityby Means of Aqueous Solutions3. Terminology3.1 DefinitionsFor definitions of terms used in these testmethods, see Terminology D 1711.4. Sampling
11、4.1 Sample shipments of material as specified below, andwhere possible take only one sample from any package.4.1.1 FabricOver 3 in. (75 mm) in width.4.1.1.1 RollsSelect one roll from each ten rolls or fractionthereof in a shipment of full-width fabric. Cut off not less thantwo turns of fabric from e
12、ach roll selected from sampling, andselect sample material for the preparation of test specimensfrom the remaining layers of the roll.1These test methods are under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and are the direct responsibility ofSubcommittee
13、 D09.07 on Flexible and Rigid Insulating Materials.Current edition approved May 1, 2007. Published June 2007. Originallyapproved in 1957. Last previous edition approved in 2001 as D 1458 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servi
14、ceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.1.2 SheetsSelect one sheet from each 50 sheets orfra
15、ction thereof in a shipment of sheeted fabric. Remove notless than six sheets from the outer layers of each package ofsheets selected from sampling, and then select sample materialfor the preparation of test specimens from the remainingsheets.4.1.2 Tapes and Strips3 in. (75 mm) and less in width.4.1
16、.2.1 TapesCut off not less than six turns of tape fromeach roll selected for sampling, and then select sample materialfor the preparation of test specimens from the remaining layersof the roll. Select rolls of tape in accordance with the followingschedule:Number of Rolls in ShipmentMinimum Number of
17、 SampleRollsOver 10 000 1 per 10005001 to 10 000 102001 to 5000 5Less than 2000 24.1.2.2 StripsSelect three strips from each 100 strips orfraction thereof in a shipment of strips. Remove not less thansix strips from the outer layers of each package of stripsselected for sampling, and then select sam
18、ple material for thepreparation of test specimens from the remaining strips.4.2 Prepare the test specimens from samples selected asspecified in 4.1, and as provided for in the individual testmethods.5. Conditioning5.1 Significance and UseThe properties of the materialdescribed in these test methods
19、are affected by the temperatureand moisture content of the material to a greater or lesserextent, depending on the specific property.5.2 ConditioningUnless otherwise specified in the indi-vidual test method, condition test specimens as described in5.2.1 or 5.2.2, and in matters of dispute, consider
20、5.2.1 as thereferee method.5.2.1 Condition the test specimens for 48 h in the StandardLaboratory Atmosphere of 50 6 2 % relative humidity at atemperature of 23 6 1 C (73.4 6 1.8 F), and conduct the testsunder these conditions.5.2.2 Condition the test specimens for 48 h in the StandardLaboratory Atmo
21、sphere of 50 6 2 % relative humidity at atemperature of 23 6 1 C (73.4 6 1.8 F), and conduct the testsimmediately upon removal of the specimens from the condi-tioning room or chamber.6. Thickness6.1 Significance and Use:6.1.1 The importance of space factor in the design ofelectrical equipment makes
22、proper determination of thicknessessential.6.1.2 Some properties, such as dielectric strength and di-electric breakdown, vary with the thickness of the material, andcertain properties, such as thermal conductivity and dielectricconstant, cannot be determined without a knowledge of thick-ness.6.2 Tes
23、t SpecimensCut specimens prepared from fabricsamples 1 in. (25 mm) wide across the entire width of thefabric, while specimens prepared from tape and strip samplesshall be the width of the sample and 36 in. (910 mm) long.Where the specimen is 36 in. or longer (full-width fabric 36 in.or more in width
24、, or where the length of a strip is 36 in. orlonger), only one specimen will be required unless otherwisespecified. Where the specimen is less than 36 in. (full-widthfabric less than 36 in. wide, or strips less than 36 in. long), asmany specimens as are needed to obtain the equivalent 36 in.linear m
25、easure will be required.6.3 ConditioningIt is not necessary to condition the speci-mens for this test. Conduct tests at the Standard LaboratoryTemperature of 23 6 1 C (73.4 6 1.8 F).6.4 ProcedureMake ten measurements, equally spacedalong 36 in. (910 mm) of the specimen or specimens inaccordance with
26、 Method C of Test Methods D 374 modified asfollows:6.4.1 Allow the presser foot to remain on the test specimenfor 2 s, at the end of which read the dial gage.6.4.2 Use a presser foot 0.250 in. (6.35 mm) in diameter,and an anvil surface upon which the specimen rests at least 2in. (51 mm) in diameter.
27、 The force exerted on the specimenshall be 3 ozf (85 g).6.4.3 Method C is not considered interchangeable withMethod A.6.5 ReportReport the average, maximum, and minimumthickness to the nearest 0.0001 in. (0.003 mm).7. Breaking Strength7.1 Significance and UseThe breaking strength of fin-ished fabric
28、 or tape is of importance as a measure of the tensionit will withstand without failure while being applied in service.7.2 ApparatusUse a power-driven tensile testing machinemeeting the requirements specified for Tensile Properties inTest Methods D 202, except that the means for determiningelongation
29、 and for recording applied load and elongation arenot required. The machine shall be equipped with specimen-gripping devices as described in 7.2.1 or 7.2.2.7.2.1 Provide two flat-jawed clamps, in which case crocuscloth will be required for holding specimens between the jaws,or7.2.2 Provide two gripp
30、ing devices of the drum type asdescribed in Fig. 1, in which case pins as indicated will berequired for securing specimens on the cylinders.7.3 Test SpecimensThe test specimen shall be of sufficientlength to provide positive gripping in the jaws with a separa-tion of approximately 6 in. (150 mm). In
31、 the case of theflat-jawed clamps, this will require a minimum specimenlength of 8 in. (200 mm) and a desirable length of 10 in. (250mm). Where drum-type gripping devices are used, a specimenno less than 20 in. (500 mm) long will be required. Prepare thespecimens from each sample as follows:7.3.1 Fa
32、bricsCut five specimens, 1 in. (25.4 mm) wide(Note 1), with sides parallel to the warp threads, and cut fivespecimens of similar width with sides perpendicular to thewarp threads (Note 2).NOTE 1Where specimens 1 in. (25.4 mm) in width have ultimatebreaking loads exceeding the capacity of the machine
33、, it is permissible toreduce the width of the specimen to not less than 0.5 in. (13 mm).NOTE 2Frequently the fill threads of glass fabrics used to manufac-ture silicone rubber-coated glass fabrics do not run in a straight line andD 1458 01 (2007)2are not perpendicular to the warp threads. Breaking s
34、trength fromspecimens cut perpendicular to the warp threads may, therefore, be highlyvariable.7.3.2 Tapes and StripsCut five specimens, 1 in. (25.4 mm)wide (see Note 2), from each sample. Where tapes or strips aremanufactured in widths less than 1 in. (25.4 mm), use thespecimen width as manufactured
35、.7.4 ConditioningIt is not necessary to condition speci-mens for this test. Conduct tests at the Standard LaboratoryTemperature of 23 6 1 C (73.4 6 1.8 F).7.5 Procedure:7.5.1 Clamp the ends of the specimen in the jaws betweentwo pieces of crocus cloth, the abrasive side of the cloth facingthe metal
36、jaws. Carefully align the specimen so that thebreaking force is parallel to the length of the specimen betweenthe jaws. Adjust the clearance between jaws to 6 in. (150 mm).7.5.2 Alternatively, loop the specimen around a binding pinof suitable diameter so that the specimen fits neither too tightlynor
37、 too loosely in the hole provided. Insert the loopedspecimen and pin in the hole provided in the drum-typegripping device. Carefully align the specimen so that thebreaking force will be parallel to the length of the specimen.Adjust the clearance between jaws to 6 in. (150 mm).7.5.3 Adjust the speed
38、of the machine in accordance withthe requirements for Tensile Properties in Test Methods D 202.7.5.4 Disregard values for breaks in or at the jaws. In thesecases, continue tests so that there are five reportable breakingstrength values per sample.7.6 Report:7.6.1 Report the average, maximum, and min
39、imum break-ing strength in pounds per inch of width (or kilograms permillimetre of width), together with the width and nominalthickness.7.6.2 In the case of fabrics, report the breaking strength inthe warp and fill directions separately.7.7 Precision and Bias:7.7.1 The precision (repeatability withi
40、n a single laboratory)of this test method has been demonstrated to be approximately17 %, expressed as a coefficient of variation of a series ofreplicate measurements on different specimens of the samesample.7.7.2 This test method has no bias because the value forbreaking strength is determined solel
41、y in terms of this testmethod itself.8. Breaking Strength After Creasing8.1 Significance and UseCreasing of silicone rubber-coated glass fabric is accompanied by breaking of some of theglass fibers at the crease and a consequent reduction inbreaking strength. The extent of this damage is related to
42、thethickness and weave of the glass fabric and the nature andthickness of the silicone rubber coating. The creasing simulatesto a degree the pinching action resulting from several succes-sive layers of tape moving relative to one another while inconfined position, such as in cables.8.2 Apparatus:8.2
43、.1 Use a metal weight adjustable between 2.25 and 4.50lbf (10 and 20 N). Mount it suitably through guides over ametal horizontal plane so that the weight may be lowered at auniform speed perpendicular to the horizontal plane. Thebottom of the weight shall be parallel to the top surface of thehorizon
44、tal plane at all times. The creasing surface of the weightis a rectangle of such dimensions that the side which isperpendicular to the crease made on the specimen is 1.5 in. (40mm). Suitable apparatus is shown in Fig. 2.8.2.2 Provide suitable means for lowering the weight at auniform rate of 12 in.
45、(300 mm)/min and of raising the weightat the end of a 2-s dwell. This may be accomplished byutilizing the breaking strength machine, described in 7.2,incombination with a system of pulleys. It may also be achievedby using a motor fitted with reducing gears and a cam, or byother devices that accompli
46、sh the purpose.8.3 Test SpecimensPrepare ten specimens as described in7.3 except that specimens shall be taken from samples of tapeor rolls of fabric only. In the case of fabric, cut the specimensin the warp direction only.8.4 Conditioning:8.4.1 It is usually not necessary to condition specimens for
47、this test. When specimens are not especially conditioned, testthem at the Standard Laboratory Temperature of 23 6 1C(73.4 6 1.8 F).8.4.2 Where it is desired to obtain the greatest degree ofreproducibility, condition specimens in accordance with 5.2.8.5 Procedure:8.5.1 Adjust the weight so that the s
48、pecimens are creased bya load of 4.5 lbf (20 N)/in. of width.8.5.2 Fold the specimen without creasing, and insert thelooped end under the weight so that the crease will be formedFIG. 1 Drum-Type Gripping DevicesD 1458 01 (2007)3under the center of the weight. Lower the weight at a uniformrate of 12
49、in. (300 mm)/min to crease the specimen.8.5.3 Allow the creased specimen to support the weight fora period of 2 s, at the end of which period lift the weight fromthe specimen.8.5.4 Determine the breaking strength of the creased speci-men in accordance with 7.5.8.6 ReportReport the following information:8.6.1 Average, maximum, and minimum breaking strengthsafter creasing, in kilograms per millimetre of width (orpounds-force per inch of width), unless otherwise specified,8.6.2 Width and nominal thickness of the specimens, and8.6.3 Conditioning of spe
