1、Designation: D 3056 05An American National StandardStandard Test Method forGel Time of Solventless Varnishes1This standard is issued under the fixed designation D 3056; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st 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 Department of Defense.1. Scope1.1 This test method covers the determinat
3、ion of the geltime of a solventless varnish mixed with a catalyst and exposedto elevated temperature.1.2 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 hea
4、lth practices and determine the applica-bility of regulatory limitations prior to use. For a specificprecaution statement, see Section 6.NOTE 1Although this standard and IEC 604552 differ in approach ordetail, data obtained using either are technically equivalent.2. Referenced Documents2.1 ASTM Stan
5、dards:2D 1711 Terminology Relating to Electrical Insulation2.2 IEC Standard:IEC 604552 Resin Based Reactive Compounds Used forElectrical Insulation Part 2: Methods of Test33. Terminology3.1 Definitions:3.1.1 gel time, nof solventless varnish, the time requiredat a specified temperature for a solvent
6、less varnish to betransformed from a liquid state to a gel as measured with asuitable gel time apparatus.3.1.2 See Terminology D 1711 for definitions of other termsrelating to electrical insulation.4. Significance and Use4.1 Gel time is important in determining batch uniformityand some processing ch
7、aracteristics. 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 nearest 0.01 g.5.4 Temperature Controller, capable of maintaining to 6 1C.5.5 Magnetic Stirrer, with a magnetized stirring bar coatedwit
8、h 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 de
9、scribed 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 100 C. Siliconeliquids must be used above 100 C but are suitabl
10、e for use atlower temperatures.NOTE 2The silicone liquid will be DC-200 or equivalent.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.1This test method is under th
11、e jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.01 on Electrical Insulating Varnishes, Powders, and Encapsu-lating Compounds.Current edition approved September 1, 2005. Published September 2005.Originally appro
12、ved in 1972. Last previous edition approved in 2000 asD 3056 00.2For 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 websi
13、te.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.4The 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., Ph
14、iladelphia, 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
15、Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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
16、 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, connec
17、t the glasstest rod to the meter, center and start the timer. The timer mustbe started within 10 s after the test tube is placed 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.
18、1 Report the following information:8.1.1 Identification of solventless varnish,8.1.2 Name and amount of catalyst used,8.1.3 Gel 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 labo
19、ratories which participated in the round robin forthis test method.59.2 BiasThis test method has no bias because the valuefor 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
20、 any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised 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
21、revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Y
22、our comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you 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 co
23、pyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual 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.
24、org (e-mail); or through the ASTM website(www.astm.org).5Supporting data are available fromASTM Headquarters. Request RR:D-9-1022TABLE 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 10.0D3056052
