1、Designation: D 5638 05An American National StandardStandard Test Method forChemical Resistance of Electrical Insulating Varnishes1This standard is issued under the fixed designation D 5638; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev
2、ision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the mechanical performance ofinsulating varnishes after exposure to variou
3、s chemicals.1.2 The values stated in SI units are the standard.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 applic
4、a-bility of regulatory limitations prior to use. See 7.1.NOTE 1There is no IEC/ISO equivalent.2. Referenced Documents2.1 ASTM Standards:2D 2519 Test Method for Bond Strength of Electrical Insu-lating Varnishes by the Helical Coil Test3. Terminology3.1 See Test Method D 2519.4. Summary of Test Method
5、4.1 Flexural strength tests are made on varnish-treatedhelical coils to determine the force required to break the coilunder specified conditions both before and after exposure toliquid chemicals.5. Significance and Use5.1 This test method is useful for the evaluation of insulat-ing varnish performan
6、ce in chemical exposure.6. Apparatus6.1 Tensile Testing MachineSee Test Method D 2519.6.2 Test FixtureSee Test Method D 2519.6.3 Chemical ContainersSealable 1000 mL containers ofsuitable material and design for containing the chemicals to beused.7. Safety Precautions7.1 It is unsafe to use varnish a
7、t temperatures above theflash point without adequate ventilation, especially if thepossibility exists that flames or sparks are present. Storevarnish in sealed containers.8. Test Specimen8.1 Prepare a minimum of five test specimens for eachchemical solution to be tested and five to determine uncondi
8、tioned bond strength in accordance with Test Method D 2519using a wire mutually agreed upon by supplier and user.9. Procedure9.1 Condition a minimum of five test specimens in eachchemical. Chemicals, test temperature and conditioning timeare mutually agreed upon by supplier and user.9.2 Test specim
9、ens both conditioned and unconditioned asdescribed in Test Method D 2519 at standard laboratoryconditions. Test conditioned specimens within 15 min ofremoval from container to minimize any change in bondstrength after exposure. Rinse conditioned specimens withwater and pat dry when water soluble che
10、micals were used forconditioning. Otherwise wipe specimens to remove excesschemical.10. Report10.1 Report the following information:10.1.1 Description of varnish,10.1.2 Identification of wire used,10.1.3 Cure time and temperature and number of dips usedto prepare the coils,10.1.4 Average bond streng
11、th in newtons (pounds-force) ofunconditioned coils,10.1.5 Average bond strength in newtons (pounds-force) ofconditioned coils,10.1.6 Description of chemical, exposure temperature, andexposure time to which the specimens were subjected, and10.1.7 Percent retention of bond strength after conditioningp
12、er the formula below.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 Encapsu-lating Compounds.Current edition approved September
13、1, 2005. Published September 2005.Originally approved in 1994. Last previous edition approved in 2000 D 5638 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
14、standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Percent Retained Bond Strength5Average Bond Strength conditionedAverage Bond Strength unconditioned3 10011. Precision and Bias11.1 Pre
15、cisionNo information has been presented toASTM upon which to base a statement of precision. Noactivity has been planned to develop such information.11.2 BiasThis test method has no bias because the valuefor chemical resistance is determined solely in terms of this testmethod.12. Keywords12.1 bond st
16、rength; chemical resistance; helical coils;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 advised that determination of the validity of any such patent right
17、s, 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 reapproved or withdrawn. Your comments are invited either for r
18、evision 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 you feel that your comments have not received a fair hearing y
19、ou 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. 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.org (e-mail); or through the ASTM website(www.astm.org).D5638052
