1、Designation: F 2357 04Standard Test Method forDetermining the Abrasion Resistance of Inks and Coatingson Membrane Switches Using the Norman Tool “RCA”Abrader1,2This standard is issued under the fixed designation F 2357; the number immediately following the designation indicates the year oforiginal a
2、doption or, in the case of revision, 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 describes the procedure for subjectinginks or coati
3、ngs on membrane switches to an abrasive mediumat a specified force.1.2 Within certain limitations, as described in this docu-ment, this test method is applicable for materials including, butnot limited to: printed or coated polyester, polycarbonate, andsilicone rubber. The samples can be either flat
4、 or contoured.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.2
5、. Referenced Documents2.1 ASTM Standards:3F 2112 Terminology for Membrane Switches3. Terminology3.1 Definitions:3.1.1 final breakthroughthe number of cycles until com-plete removal of the first surface ink or coating being tested.3.1.2 membrane switcha momentary switching device inwhich at least one
6、 contact is on, or made of, a flexiblesubstrate.3.1.3 wear limitin testing membrane switches, the numberof cycles until an underlying layer of different color may beseen through the first layer (not applicable for transparentcoatings).4. Significance and Use4.1 Membrane Switch keys are subjected to
7、repeated actua-tions, usually by a human finger. They are also subjected toother conditions (for example, wiping, cleaning, rubbing)during handling, end-use, shipment, or storage that may causeabrasion damage. The result may be a significant removal ofthe coatings, text or decorative inks.4.2 This t
8、est method is applicable to a wide range ofmaterials. The main criterion is that the abrasion processproduces visible wear or breakthrough in the surface beingtested.4.3 The amount of abrasion damage to a surface is depen-dent on numerous variables. This test method provides a wayof comparing relati
9、ve abrasion resistance of inks and coatings.In no way do the results provide a correlation value of thenumber of human finger touches before coating failure. It onlyprovides a means to compare results of tests performed usingthe same equipment, abrasive materials and loading conditions.4.4 The test
10、method can be used for quality control pur-poses, as a research and development tool, to evaluate materialcombinations for a given application, or for the comparison ofmaterials with relatively similar properties.5. Interferences5.1 Inconsistent wear can occur which will compromise theresults. Cauti
11、on is necessary to ensure the mounting methoddoes not deflect the specimen, which may influence the wearcharacteristics.5.2 Contoured surfaces can be tested but results may bemore difficult to duplicate and some equipment is not designedto test non-flat surfaces.5.3 Whenever possible, a smooth surfa
12、ce is preferred. Extracare should be taken when evaluating a non-uniform surface(that is, rough surface), and for the user to recognize potentialvariations between specimens.6. Apparatus6.1 Machine capable of providing cyclic or continuousabrasion to a test specimen under controlled loading condi-ti
13、ons.6.2 Suggested Sources:1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.18 on MembraneSwitches.Current edition approved March 1, 2004. Published April 2004.2The Norman Tool “RCA” Abrader is covered by a patent. In
14、terested parties areinvited to submit information regarding the identification of an alternative(s) to thispatented item to the ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee, whichyou may attend.3For referenced AS
15、TM 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
16、ocken, PA 19428-2959, United States.6.2.1 Norman Tool RCA Abrader.46.3 Specimen Mounting Fixture or Holder, a suitable deviceof sufficient strength and rigidity used to secure the specimenso that it is held rigidly and perpendicular to the load duringtesting.6.4 Abrasive Media, commonly available fr
17、om NormanTool.6.4.1 0.6875 in. wide Paper, most applications.6.4.2 0.25 in. wide Polyester Tape, recommended for speci-mens with concave surfaces and fine graphic details.7. Conditioning7.1 Abrasive Media and Specimen ConditioningUnlessotherwise agreed upon between purchaser and seller, conditionthe
18、 specimens for at least 24 h at 23 6 2C (73.4 6 3.6F) and50 6 10 % relative humidity.7.2 Test ConditionsConduct tests in the standard labora-tory atmosphere of 23 6 2C and 50 6 10 % relative humidity.8. Pre-Test Setup8.1 Mount the test specimen on the mounting fixture. Thisholding device should firm
19、ly hold the test specimen in a fixedposition, without distortion, in a perpendicular position relativeto the force probe.8.2 Cleaning of SpecimenSpecimens shall be cleaned insuch a way that the surface is free from grit, grease, fingerprintsor other contaminates.8.2.1 Use a clean lint-free piece of
20、absorbent material andeither reagent grades of n-heptane or isopropyl alcohol.8.2.2 Lightly wipe the surface of the test area with amoistened piece of cleaning material.8.2.3 Allow the surface to air dry completely (minimum twohours).8.2.4 Inspect the test area to ensure no visual damage hasbeen cau
21、sed by the cleaning process.8.3 Inspect for residue and quality of ink or coating in areaof test.8.4 Install specified abrasive material.8.5 Adjust applied force to specified value.9. Procedure9.1 Align specimen targeted test point to the applied forceprobe.9.2 Adjust force to be applied to 175 g (o
22、r otherwisespecified).9.3 Gently lower the abradant onto the specimen.9.4 Start the abrasion process.9.5 Subject the test specimen to abrasion for the specifiednumber of cycles; or until sought after visual change has beendetected. Wear Limit is determined when an underlying layerof different color
23、may be seen through the first layer (notapplicable for transparent coatings). In determining the extentof wear, periodically interrupt the instrument at intervals forexamination of the test specimen. Final Breakthrough, notwear, on a first surface printed line constitutes a failureregardless of size
24、.NOTE 1Caution: When the test is stopped prior to achieving final endpoint, it is recommended the specimen not be moved. Doing so maypresent problems in aligning the wear path for additional testing.9.6 Periodically remove any loose abrading that remains onthe test specimen, by light brushing or com
25、pressed air.10. Report10.1 Report the following information:10.1.1 Model number and description of Abrasion Testerused,10.1.2 Abrasive material,10.1.3 Force applied to specimen,10.1.4 Number of cycles to wear limit (not applicable fortransparent coatings),10.1.5 Number of cycles to final breakthroug
26、h,10.1.6 Temperature and humidity,10.1.7 Identity of specimen, describing the material orcoating,10.1.8 Method of cleaning, if applicable, and10.1.9 Visual evaluation of test specimen and include pho-tos of target test area, if possible.11. Precision and Bias11.1 Precision and bias have not been det
27、ermined at thistime, but will be developed by the subcommittee F01.18.12. Keywords12.1 abrasion; breakthrough; coatings; inks; membraneswitch; Norman Tool; RCA; Taber; wearASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
28、in 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 revision at any time by the responsible technical committee and m
29、ust 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 will receive careful consideration at a meeting of t
30、heresponsible 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 ASTM International, 100 Barr Harbor Drive, PO Box C7
31、00, 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).4Available from Norman Tool Co., 15415 Old State Road, Evansville, IN 47725;812-867-3496.F2357042
