ASTM_D_3056_-_14.pdf

Designation:D305614Standard Test Method forGel Time of Solventless Varnishes1This standard is issued under the fixed designation D3056;the number immediately following the designation indicates the 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()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This test method covers the determination of the geltime of a solventless varnish mixed with a catalyst,if required,and exposed to elevated temperature.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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 safety and health practices and determine the applica-bility of regulatory limitations prior to use.For a specificprecaution statement,see Section 6.NOTE1Although this standard and IEC 604552 differ in approach ordetail,data obtained using either are technically equivalent.2.Referenced Documents2.1 ASTM Standards:2D1711 Terminology Relating to Electrical Insulation2.2 IEC Standard:3IEC 604552 Resin Based Reactive Compounds Used forElectrical InsulationPart 2:Methods of Test3.Terminology3.1 Definitions:3.1.1 gel time,nof solventless varnish,the time requiredat a specified temperature for a solventless varnish to betransformed from a liquid state to a gel as measured with asuitable gel time apparatus.3.1.2 See Terminology D1711 for definitions of other termsrelating to electrical insulation.4.Significance and Use4.1 Gel time is important in determining batch uniformityand some processing characteristics.It is indicative of pot lifeand shelf life.5.Apparatus5.1 Gel Time Apparatus.45.2 Power Supply,110 V ac variable.5.3 Balance,with accuracy to the nearest 0.01 g.5.4 Temperature Controller,capable of maintaining to61C.5.5 Magnetic Stirrer,with a magnetized stirring bar coatedwith a tetrafluoroethylene.6.Safety Precautions6.1 It is unsafe to use varnish at temperatures above theflash point without adequate ventilation,especially if thepossibility exists that flames or sparks are present.Storevarnish in sealed containers.7.Procedure7.1 Set up the gel time apparatus as described in theinstruction manual supplied by the manufacturer.7.2 Fill the bath with water or a silicone liquid to completelyimmerse the test specimen of solventless varnish when the testtube is placed in the bath.Water is useful up to 100C.Siliconeliquids must be used above 100C but are suitable for use atlower temperatures.NOTE2The silicone liquid will be DC-200 or equivalent.1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.01 on Electrical Insulating Varnishes,Powders and Encapsulat-ing Compounds.Current edition approved Nov.1,2014.Published November 2014.Originallyapproved in 1972.Last previous edition approved in 2010 as D3056 05(2010).DOI:10.1520/D3056-14.2For 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 standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.4The sole source of supply of the apparatus known to the committee at this timeis Sunshine Gel Time Meter,Catalog No.22,manufactured by Sunshine ScientificInstruments,1810 Grant Ave.,Philadelphia,PA 19115.If you are aware ofalternative suppliers,please provide this information to ASTM InternationalHeadquarters.Your comments will receive careful consideration at a meeting of theresponsible technical committee,4which you may attend.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.3 Place the bath on the magnetic stirrer,and insert thestirring bar into the bath.Connect the heating coil to thetemperature controller.Start the cold water on the bath con-denser.7.4 Adjust the bath to the desired temperature.7.5 If the varnish requires the addition of catalyst,weigh100 6 1 g of solventless varnish into a 150-mL beaker andrecord the mass to the nearest 0.01 g.7.6 Weigh the desired amount of catalyst to an accuracy of61%into the 100 g of solventless varnish and mix thoroughly.7.7 Weigh 9.5 to 10.5 g of catalyzed solventless varnish intoa 16 by 150-mm test tube.7.8 Insert the glass test rod from the gel time apparatus inthe test tube.7.9 Quickly place the test tube in the bath,connect the glasstest rod to the meter,center and start the timer.The tim