1、Designation: D3056 05 (Reapproved 2010)D3056 14Standard 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 re
2、vision. 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 Scope*1.1 This test method covers the dete
3、rmination of the gel time of a solventless varnish mixed with a catalyst catalyst, if required,and exposed to elevated temperature.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to addre
4、ss all of the safety concerns, if any, associated 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. For a specific precaution statement, see Section 6.NOTE 1Al
5、though this standard and IEC 604552 differ in approach or detail, 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 for Electrical Insula
6、tion Part InsulationPart 2: Methods of Test3. Terminology3.1 Definitions:3.1.1 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.3.1.2 See Terminology
7、D1711 for definitions of other terms relating to electrical insulation.4. Significance and Use4.1 Gel time is important in determining batch uniformity and some processing characteristics. It is indicative of pot life andshelf life.5. Apparatus5.1 Gel Time ApparatusApparatus.4.5.2 Power Supply, 110
8、V ac variable.5.3 Balance, with accuracy to the nearest 0.01 g.5.4 Temperature Controller, capable of maintaining to 6 1 C.61C.5.5 Magnetic Stirrer, with a magnetized stirring bar coated with a tetrafluoroethylene.1 This test method is under the jurisdiction of ASTM Committee D09 on Electrical and E
9、lectronic Insulating Materials and is the direct responsibility of SubcommitteeD09.01 on Electrical Insulating Varnishes, Powders and Encapsulating Compounds.Current edition approved May 1, 2010Nov. 1, 2014. Published September 2010November 2014. Originally approved in 1972. Last previous edition ap
10、proved in 20052010as D3056D3056 05 (2010).05. DOI: 10.1520/D3056-05R10.10.1520/D3056-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summar
11、y page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 The sole source of supply of the apparatus known to the committee at this time is Sunshine Gel Time Meter, Catalog No. 22, manufactured by Sun
12、shine ScientificInstruments, 1810 Grant Ave., Philadelphia, PA 19115. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Yourcomments will receive careful consideration at a meeting of the responsible technical committee,4 which you may att
13、end.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 recommends that users consult prior
14、 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 C700, West Conshohocken, PA 19428
15、-2959. United States16. Safety Precautions6.1 It is unsafe to use varnish at temperatures above the flash point without adequate ventilation, especially if the possibilityexists that flames or sparks are present. Store varnish in sealed containers.7. Procedure7.1 Set up the gel time apparatus as des
16、cribed in the instruction manual supplied by the manufacturer.7.2 Fill the bath with water or a silicone liquid to completely immerse the test specimen of solventless varnish when the testtube is placed in the bath. Water is useful up to 100 C. 100C. Silicone liquids must be used above 100 C 100C bu
17、t are suitablefor use at lower temperatures.NOTE 2The silicone liquid will be DC-200 or equivalent.7.3 Place the bath on the magnetic stirrer, and insert the stirring bar into the bath. Connect the heating coil to the temperaturecontroller. Start the cold water on the bath condenser.7.4 Adjust the b
18、ath to the desired temperature.7.5 If the varnish requires the addition of catalyst, weigh 100 6 1 g of solventless varnish into a 150-mL beaker and record themass to the nearest 0.01 g.7.6 Weigh the desired amount of catalyst to an accuracy of 61 % into the 100 g of solventless varnish and mix thor
19、oughly.7.7 Weigh 9.5 to 10.5 g of catalyzed solventless varnish into a 16 by 150-mm test tube.7.8 Insert the glass test rod from the gel time apparatus in the test tube.7.9 Quickly place the test tube in the bath, connect the glass test rod to the meter, center and start the timer. The timer mustbe
20、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 the meter indicates completion of test. The meter will shut off whenthe specimen has gelled.8. Report8.1 Report the following information:8.1.1 Identification of solventless varnish
21、,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 Precision Precision The data in Table 1 are the combined results of five laboratories which participated in the roundrobin for this test method
22、.59.2 BiasThis test method has no bias because the value for gel time is defined solely in terms of this test method.10. Keywords10.1 gel time; solventless varnish; varnish5 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D09-10
23、22.TABLE 1 Round-Robin Test ResultsNOTE 1Testing was done using an unsaturated polyester varnish in200-cP silicone oil at 100 C.100C.colwidth=“1.25in“/COLSPECCatalyst Gel Time,Avg, Min InterlaboratoryStandard DeviationTertiary butyl perbenzoate, 1 % 17.5 2.8Dicumyl peroxide, 1 % 78.4 10.0D3056 142SU
24、MMARY OF CHANGESCommittee D09 has identified the location of selected changes to this standard since the last issue (D3056 05(2010) that may impact the use of this standard. (Approved Nov. 1, 2014.)(1) Revised subsection 1.1.ASTM International takes no position respecting the validity of any patent
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26、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. Your comments
27、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 copyrighted by
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