1、Designation: D4733 13D4733 17Standard 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 the case of revision, the year of last revision.
2、 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 solventless varnishes used primarily as electrical, mechanical, and environmental protection forelectrical
3、 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 electrical equipment. Thefollowing test methods are included
4、: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 15Dielectric Strength-Using Metal Panels 16Permittivity and D
5、issipation Factor 17Build 18Property Tests (Uncured): SectionDensity 7Flash Point 8Gel Time 9Monomer Content 10Rheological Properties (Non-Newtonian) 11Rotational Viscosity 12Performance Property Tests (cured):Bond Strength 13Coating Thickness 14Dielectric Strength 15Dielectric Strength-Using Metal
6、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, associated with its use. It is the
7、 responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations 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 IE
8、C 60455. Since both methods contain multiple test procedures, many procedures are technically equivalentwhile others differ significantly.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles
9、 for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.1 These test methods are under the jurisdiction ofASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct respo
10、nsibility of SubcommitteeD09.01 on Electrical Insulating Varnishes, Powders and Encapsulating CompoundsProducts.Current edition approved April 1, 2013Nov. 1, 2017. Published April 2013November 2017. Originally approved in 1987. Last previous edition approved in 20092013 asD4733 03 (2009).D4733 13. D
11、OI: 10.1520/D4733-13.10.1520/D4733-17.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 r
12、ecommends 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
13、 C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:2D93 Test Methods for Flash Point by Pensky-Martens Closed Cup TesterD115 Test Methods for Testing Solvent Containing Varnishes Used for Electrical InsulationD149 Test Method for Dielectric Breakdown Vol
14、tage 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 Test Method for Coke Residue of Creosote (Withdrawn 2006)3D374 Test Methods for
15、Thickness of Solid Electrical Insulation (Metric) D0374_D0374MD923 Practices for Sampling Electrical Insulating LiquidsD1475 Test Method for Density of Liquid Coatings, Inks, and Related ProductsD1711 Terminology Relating to Electrical InsulationD2196 Test Methods for Rheological Properties of Non-N
16、ewtonian Materials by Rotational ViscometerD2519 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 Method for Perc
17、ent 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 (Withdrawn 2012)
18、3E176 Terminology of Fire Standards2 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
19、of this historical standard is referenced on www.astm.org.D4733 1722.2 IEC StandardsIEC 60455 Resin Based Reactive CompundsCompounds 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 t
20、erms associated withfire 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
21、 material to thin upon 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 el
22、ectrical insulating varnishsolvent-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. Signific
23、ance and Use4.1 The test 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 t
24、he quality of the product 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 h
25、aving a specific gravity 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
26、Sample solventless varnishes 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 usin
27、g an aspirator-type sampling 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 M
28、ethod D923.5.2.3 Sample 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
29、 Non-Newtonian Viscosity: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 ma
30、terial specification, 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.TES
31、T METHODS7. Density7.1 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 millilit
32、re) at 70 to 77F (20 to 25C).D4733 1737.2 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), and
33、7.3.4 The mean, the range, 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 va
34、rnishes having a flash 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 itssurfac
35、e. The temperature at ignition is taken as the flash point.8.3 This standard is used to measure and describe the response of materials, products, or assemblies to heat and flame undercontrolled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessmen
36、t of the materials,products or assemblies under actual fire conditions.8.4 Fire testing is inherently 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 th
37、e materials of 8.1.2 in accordance with Test Method D3278.8.6 ReportReport information in accordance 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 eleva
38、ted temperatures.9.2 Significance and UseKnowledge of gel time is important for determining shelf 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,
39、9.4.2 The reactor or catalyst and quantity used shall be described if the reactor or catalyst is supplied in a separate package,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
40、 of the percent monomer having a vapor pressure exceeding 0.1 Torr (13Pa) at 77F (25C).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 also has the pot
41、ential to affect the physical andelectrical properties of the cured resin.10.3 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.11. Rheological P
42、roperties (Non-Newtonian)11.1 ScopeThis test method covers the determination 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 tr
43、eatment of the sample in order to determine this property.D4733 17411.3 ProcedureTest for thixotropy in accordance with Test Method D2196, Method B or C.11.4 ReportReport information as specified in Test Method D2196.12. BrookfieldRotational Viscosity12.1 ScopeThis test method covers the determinati
44、on of viscosity for liquids having flow properties approaching those of thenewtonian solutions.12.2 Apparatus:12.2.1 BrookfieldRotational 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
45、 and stirrer if necessary. Allow thespecimen to sit in the water bath at 77 6 2F until no bubbles are visible in the specimen.12.3.2 Make all measurements with the Brookfieldrotation viscometer at 77 6 2F (25 6 1.0C).12.4 ReportReport information as specified in Test Method D2196.12.5 Precision and
46、Bias:12.5.1 PrecisionSee Test Method D2196 for a statement of precision.12.5.2 BiasSee Test Method D2196 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 Significan
47、ce and UseValues obtained by flexural test can provide information with regard to the bond strength of aparticular 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 informa
48、tion in accordance with Test Method D2519.13.5 Precision and Bias:13.5.1 PrecisionSee Test Method D2519 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 wi
49、th a solventless varnish.14.1.2 The shear history of the varnish immediately preceding the test has the potential to have an appreciable effect on thecoating thickness obtained. This test method specifies the degree of shear of the sample and the rate of withdrawal of the specimenin 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
