1、Designation: D4733 03 (Reapproved 2009)D4733 13 An American National StandardStandard Test Methods forSolventless Electrical Insulating Varnishes1This standard is issued under the fixed designation D4733; the number immediately following the designation indicates the year oforiginal adoption or, in
2、the case of revision, the year 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.1. Scope Scope*1.1 These test methods cover solventless varnishes used primarily as electrical,
3、mechanical, and environmental protection forelectrical equipment.1.2 These test methods are used on solventless varnishes that are applied by dipping (at atmospheric pressure conditions orunder vacuum or other certain pressure), spraying, or brushing for the purpose of impregnating or sealing electr
4、ical equipment. Thefollowing test methods are included:Property Tests (Uncured): SectionDensity 7Flash Point 8Gel Time 9Monomer Content 10Rheological Properties (Non-Newtonian) 11Brookfield Viscosity 12Performance Property Tests (cured):Bond Strength 13Coating Thickness 14Dielectric Strength 15Diele
5、ctric Strength-Using Metal Panels 16Permittivity and Dissipation Factor 17Build 181.3 The values stated in inch-pound units are to be regarded as the standard. The values in parentheses are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associa
6、ted with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. Specific hazard statements are given in 8.3, 15.5.1, and 15.5.2.NOTE 1This test method is related to IEC
7、60455. Since both methods contain multiple test procedures, many procedures are technically equivalentwhile others differ significantly.2. Referenced Documents2.1 ASTM Standards:2D93 Test Methods for Flash Point by Pensky-Martens Closed Cup TesterD115 Test Methods for Testing Solvent Containing Varn
8、ishes Used for Electrical InsulationD149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials atCommercial Power FrequenciesD150 Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical InsulationD168
9、 Test Method for Coke Residue of Creosote (Withdrawn 2006)3D374 Test Methods for Thickness of Solid Electrical Insulation (Withdrawn 2013)3D923 Practices for Sampling Electrical Insulating LiquidsD1475 Test Method For Density of Liquid Coatings, Inks, and Related ProductsD1711 Terminology Relating t
10、o Electrical InsulationD2196 Test Methods for Rheological Properties of Non-Newtonian Materials by Rotational (Brookfield type) Viscometer1 These test methods are under the jurisdiction ofASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of Subcomm
11、itteeD09.01 on Electrical Insulating Varnishes, Powders and Encapsulating Compounds.Current edition approved Oct. 1, 2009April 1, 2013. Published February 2010April 2013. Originally approved in 1987. Last previous edition approved in 20032009 asD4733 03.D4733 03 (2009). DOI: 10.1520/D4733-03R09.10.1
12、520/D4733-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. ForAnnual Book ofASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical sta
13、ndard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM rec
14、ommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C
15、700, West Conshohocken, PA 19428-2959. United States1D2519 Test Method for Bond Strength of Electrical Insulating Varnishes by the Helical Coil TestD3056 Test Method for Gel Time of Solventless VarnishesD3278 Test Methods for Flash Point of Liquids by Small Scale Closed-Cup ApparatusD3312 Test Metho
16、d for Percent Reactive Monomer in Solventless VarnishesD3487 Specification for Mineral Insulating Oil Used in Electrical ApparatusD3636 Practice for Sampling and Judging Quality of Solid Electrical Insulating MaterialsD6054 Practice for Conditioning Electrical Insulating Materials for Testing (Withd
17、rawn 2012)3E176 Terminology of Fire StandardsD4733 1322.2 IEC StandardsIEC 60455 Resin Based Reactive Compunds Used for Electrical Insulation3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in these test methods, refer to Terminology D1711. For definitions of terms associated withfi
18、re issues, refer to Terminology E176.3.1.2 gel time, nof solventless varnish, the time required at a specified temperature for a solventless varnish to be transformedfrom a liquid state to a gel as measured with a suitable gel time apparatus.3.1.3 thixotropy, nthe property of a material to thin upon
19、 isothermal agitation and to thicken upon subsequent rest.3.1.4 varnish, electrical insulating, na liquid resin system that is applied to and cured on electrical components providingelectrical, mechanical, and environmental protection.3.1.4.1 DiscussionThere are two types of electrical insulating va
20、rnishsolvent-containing and solventless. The solvent-containing varnish issolution, dispersion, or emulsion of a polymer or a mixture of polymers in a volatile, nonreactable liquid. The solventless type isa liquid resin system free of volatile, nonreactable solvents.4. Significance and Use4.1 The te
21、st methods referenced in these test methods are useful for control purposes during the manufacture and use ofsolventless varnishes.5. Sampling5.1 Accurate sampling, whether of the complete contents or only parts thereof, is extremely important from the standpoint ofevaluating the quality of the prod
22、uct sampled. In most cases, the detection of contaminants that are not ordinarily disperseduniformly through the liquid being sampled such as water or solid particles, necessitates taking samples at specific locations wherethe contaminants are likely to be found. For a liquid having a specific gravi
23、ty less than one, water and other impurities are mostlikely to be found on the bottom; whereas in the case of liquids having a specific gravity greater than one, these impurities are mostlikely to be found on the surface.5.2 Sampling Fluids Exhibiting Newtonian Viscosity:5.2.1 Sample solventless var
24、nishes having an approximate viscosity of 25 cP (0.025 Pas) or less at 100F (37.8C) using thesampling device shown in Fig. 1 of Test Method D923. However, if the temperature of the material is below room temperatureor if the humidity is above 75 % relative humidity, sample using an aspirator-type sa
25、mpling device as shown in Fig. 2 of TestMethod D923.5.2.2 Sample solventless varnishes having a viscosity from 25 to 650 cP (0.025 to 0.65 Pas) at 100F (37.8C) and wherecontact with the atmosphere must be avoided, use a pressure-type sampling device as shown in Fig. 3 of Test Method D923.5.2.3 Sampl
26、e solventless varnishes having a viscosity above 650 cP at 100F at 73 6 10F (23 6 5C). Open the container andmix slowly so as not to entrap air. When the material is homogeneous, take samples from two or three places on the surface andmix together.5.3 Sampling Fluids Exhibiting Non-Newtonian Viscosi
27、ty:5.3.1 Sample solventless varnishes exhibiting non-Newtonian viscosity in accordance with 5.2.3.5.4 Use sample containers and sampling procedures in accordance with Test Method D923.5.5 When a sampling method is needed to determine whether a lot meets the requirements of a material specification,
28、usePractice D3636 as a guide.6. Conditioning6.1 Condition test specimens at standard laboratory condition as specified in Practice D6054.6.2 Deaerate specimens to be used for property evaluation before curing using the vacuum technique recommended by thevarnish manufacturer.TEST METHODS7. Density7.1
29、 ScopeThis test method covers the measurement of the density using a pycnometer. It is particularly applicable where thefluid has too high a viscosity for other methods of testing density. In this test method the density will be expressed as pounds pergallon (grams per millilitre) at 70 to 77F (20 t
30、o 25C).D4733 1337.2 ProcedureTest for density in accordance with Test Method D1475.7.3 ReportReport the following information:7.3.1 Identification of the test sample,7.3.2 The test temperature to the nearest 0.2F (0.1C),7.3.3 Density to the nearest 0.01 lb/gal (0.001 g/mL), and7.3.4 The mean, the ra
31、nge, and the number of replicate determinations.8. Flash Point8.1 ScopeThis test method covers the determination of the flash point of solventless varnishes. There are two types ofmaterials involved:8.1.1 Those varnishes having a flash point above 230F (110C), and8.1.2 Those varnishes having a flash
32、 point below 230F (110C).8.2 Summary of Test MethodA specified amount of sample is added to the instrument. The temperature of the material isincreased at a constant rate until a small flame ignites the vapor of the specimen in the tester and propagates a flame across itssurface. The temperature at
33、ignition is taken as the flash point.8.3 This test method should be used to measure and describe the response of materials, products, or assemblies to heat andflame under controlled conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products,or assem
34、blies under actual fire conditions. However, results of this test may be used as elements of a fire hazard assessment ora fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of aparticular end use. This standard is used to measure
35、and describe the response of materials, products, or assemblies to heat andflame under controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment ofthe materials, products or assemblies under actual fire conditions.8.4 Fire testing is inher
36、ently hazardous. Adequate safeguards for personnel and property shall be employed in conducting thesetests.8.5 Procedure:8.5.1 Test the materials of 8.1.1 in accordance with Test Methods D93.8.5.2 Test the materials of 8.1.2 in accordance with Test Method D3278.8.6 ReportReport information in accord
37、ance with the report section of the test method used.9. Gel Time9.1 ScopeThis test method covers the determination of gel time of a solventless varnish mixed with a reactor or catalyst andexposed to elevated temperatures.9.2 Significance and UseKnowledge of gel time is important for determining shel
38、f life, batch uniformity, and processingcharacteristics.9.3 ProcedureTest for gel time in accordance with Test Method D3056.9.4 ReportReport the following information:9.4.1 Identification of the material,9.4.2 The reactor or catalyst and quantity used shouldshall be stateddescribed if the reactor or
39、 catalyst is supplied in a separatepackage,9.4.3 Gel time to the nearest 0.1 min,9.4.4 Temperature of the bath, and9.4.5 Liquid used in the bath.10. Monomer Content10.1 ScopeThis test method covers the determination of the percent monomer having a vapor pressure exceeding 0.1 Torr (13Pa) at 77F (25C
40、).10.2 Significance and UseThe percent of reactive monomer in a solventless varnish will affect the viscosity, handling, andprocessing properties of the uncured resin. The amount of reactive monomer may also also has the potential to affect the physicaland electrical properties of the cured resin.10
41、.3 ProcedureTest for the monomer content in accordance with Test Method D3312.10.4 ReportReport the following information:10.4.1 Identification of the solventless varnish, and10.4.2 Percent reactive monomer.D4733 13411. Rheological Properties (Non-Newtonian)11.1 ScopeThis test method covers the dete
42、rmination of the rheological properties of solventless varnishes that arenon-newtonian in character.11.2 Significance and UseThis test method is used to test solventless varnishes that are thixotropic in nature and requirespecific treatment of the sample in order to determine this property.11.3 Proc
43、edureTest for thixotropy in accordance with Test Method D2196, Method B or C.11.4 ReportReport information as specified in Test Method D2196.12. Brookfield Viscosity12.1 ScopeThis test method covers the determination of viscosity for liquids having flow properties approaching those of thenewtonian s
44、olutions.12.2 Apparatus:12.2.1 Brookfield Viscometer.12.2.2 Thermometer.12.2.3 Water Bath.12.2.4 Stirrer.12.3 Procedure:12.3.1 Bring the specimen to a temperature of 77 6 2F (25 6 1.0C) using a water bath and stirrer if necessary. Allow thespecimen to sit in the water bath at 77 6 2F until no bubble
45、s are visible in the specimen.12.3.2 Make all measurements with the Brookfield viscometer at 77 6 2F (25 6 1.0C).12.4 ReportReport information as specified in Test Method D2196.12.5 Precision and Bias:12.5.1 PrecisionSee Test Method D2196 for a statement of precision.12.5.2 BiasSee Test Method D2196
46、 for a statement of bias.13. Bond Strength13.1 ScopeThis test method covers the determination of the bond strength of an electrical insulating varnish when applied toa helical coil.13.2 Significance and UseValues obtained by flexural test can provide information with regard to the bond strength of a
47、particular varnish in combination with a particular wire when measured under the prescribed conditions.13.3 ProcedurePerform the test in accordance with Test Method D2519.13.4 ReportReport information in accordance with Test Method D2519.13.5 Precision and Bias:13.5.1 PrecisionSee Test Method D2519
48、for a statement of bias.13.5.2 BiasSee Test Method D2519 for a statement of bias.14. Coating Thickness14.1 Scope:14.1.1 This test method is used to determine the thickness of a coating obtained with a solventless varnish.14.1.2 The shear history of the varnish immediately preceding the test may has
49、the potential to have an appreciable effect onthe coating thickness obtained. This test method specifies the degree of shear of the sample and the rate of withdrawal of thespecimen in order to arrive at a reproducible buildup on a test specimen.14.2 Apparatus:14.2.1 Device, capable of withdrawing a specimen at approximately 4 in./min (100 mm/min).14.2.2 Water Bath, or conditioned room controlled to a temperature of 75 6 2F (24 6 1C).14.2.3 Thermometer, with a range of 32 to 212F (0 to 100C).14.2.4 Test Panel, cons
