1、Designation: D3056 05 (Reapproved 2010)An American National StandardStandard 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
2、, 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 Department of Defense.1. Scope1.1 This test method covers
3、 the determination of the geltime of a solventless varnish mixed with a catalyst and exposedto 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 thesafe
4、ty 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.NOTE 1Although this stan
5、dard 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 Insulation Part 2: Metho
6、ds 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 term
7、srelating 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 Apparatus4.5.2 Power Supply, 110 V ac variable.5.3 Balance, with accuracy to the
8、 nearest 0.01 g.5.4 Temperature Controller, capable of maintaining to 6 1C.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 thepo
9、ssibility 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 solventle
10、ss varnish when the testtube is placed in the bath. Water is useful up to 100 C. Siliconeliquids must be used above 100 C but are suitable for use atlower temperatures.NOTE 2The silicone liquid will be DC-200 or equivalent.1This test method is under the jurisdiction of ASTM Committee D09 onElectrica
11、l and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.01 on Electrical Insulating Varnishes, Powders and Encapsulat-ing Compounds.Current edition approved May 1, 2010. Published September 2010. Originallyapproved in 1972. Last previous edition approved in 2005 as
12、D305605. DOI:10.1520/D3056-05R10.2For 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 Nat
13、ional 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,
14、 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO B
15、ox C700, West Conshohocken, PA 19428-2959, United States.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
16、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
17、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 timer mustbe started within 10 s after the test tube is plac
18、ed in the bath.7.10 Allow the test specimen to remain in the bath until themeter indicates completion of test. The meter will shut offwhen the specimen has gelled.8. Report8.1 Report the following information:8.1.1 Identification of solventless varnish,8.1.2 Name and amount of catalyst used,8.1.3 Ge
19、l time to the nearest 0.1 min, and8.1.4 Temperature of the bath and the liquid used.9. Precision and Bias9.1 PrecisionThe data in Table 1 are the combined resultsof five laboratories which participated in the round robin forthis test method.59.2 BiasThis test method has no bias because the valuefor
20、gel time is defined solely in terms of this test method.10. Keywords10.1 gel time; solventless varnish; varnishASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advise
21、d that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either re
22、approved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If y
23、ou feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individua
24、l reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from
25、the ASTM website (www.astm.org/COPYRIGHT/).5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D09-1022.TABLE 1 Round-Robin Test ResultsNOTE 1Testing was done using an unsaturated polyester varnish in200-cP silicone oil at 100 C.Catalyst Gel Time, Avg, MinInterlaboratory Stan-dard DeviationTertiary butyl perbenzoate, 1 % 17.5 2.8Dicumyl peroxide, 1 % 78.4 10.0D3056 05 (2010)2
