1、Designation: F 1843 97 (Reapproved 2002)Standard Practice forSample Preparation of Transparent Plastic Films forSpecular Gloss Measurements, on Membrane SwitchOverlays1This standard is issued under the fixed designation F 1843; the number immediately following the designation indicates the year ofor
2、iginal adoption 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 practice covers the method of sample preparation,prior
3、to taking gloss measurements on a membrane switchoverlay.1.2 Typical applications include window display areas on agraphic overlay, and surface texture.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 thi
4、s standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 523 Test Method for Specular Gloss23. Terminology3.1 Definitions:3.1.1 membrane switch, na momentary switching devicein
5、 which at least one contact is on (or made of) a flexiblesubstrate.3.1.2 specular gloss, nthe degree to which a surfacesimulates a perfect mirror in its capacity to reflect incidentlight.3.1.3 overlay, nthe outer layer of a membrane switch onwhich the graphics are printed.4. Summary of Practice4.1 A
6、 water or alcohol droplet is placed on a black metalplate. The specimen to be measured is pressed down over thedroplet. Capillary action causes intimate contact betweenspecimen and plate, thereby eliminating second surface reflec-tion. Gloss readings may then be taken in accordance with TestMethod D
7、 523.5. Significance and Use5.1 Gloss measurements are used to qualify a raw materialor finished product.5.2 Sample preparation will effect the outcome of glossreadings. This practice will eliminate second surface reflection,and allow a more accurate gloss reading of the substrate.5.3 Materials whic
8、h require this preparation include thefollowing: clear or translucent substrates, colored transparentsubstrates, and areas printed with clear, translucent, or trans-parent colored coatings.6. Apparatus6.1 Gloss Meter, in accordance with Test Method D 523.6.2 Black Iodized Aluminum Test Plate3, This
9、plate is to bea hard, flat, smooth, matte black, nonporous surface. Glossreadings should be between 4 to 12 gloss units, when measuredwith a 60 gloss meter. Plate size should be sufficient to allowthe specimen to be laid flat for readings, typically 12 by 12 in.(304.8 by 304.8 mm). Material thicknes
10、s to be 0.062 in. ( 1.57mm) or thicker.6.3 Distilled Water,orIsopropyl Alcohol.6.4 Eye Dropper.6.5 Hand Held Brayer (rubber roller).7. Procedure7.1 Verify the specimen and plate are clean, dry, and free ofcontamination.7.2 Use the eyedropper to place a few drops of distilledwater or isopropyl alcoho
11、l in the center of the black plate.7.3 Position the specimen over the droplet(s), with the siderequiring a gloss reading facing up.7.4 Slowly press the specimen down onto the plate.7.5 Smooth out the specimen using a brayer. The measure-ment area of the specimen will appear darker, which is anindica
12、tion of intimate contact.1This practice is under the jurisdiction of ASTM Committee F01 on Electronicsand is the direct responsibility of Subcommittee F01.18 on Membrane Switches.Current edition approved Dec. 10, 1997. Published February 1998.2Annual Book of ASTM Standards, Vol 06.01.3A black anodiz
13、ed aluminum plate with the designation “AAM21C22A43-DYED BLACK, ALUMINUM ALLOY 6061 -T6 matte etch” is suitable for thispurpose.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.6 The measurement area should be large enough to covert
14、he sample port of the gloss meter.7.7 Ensure there are no air bubbles within the measurementarea. Air entrapment will prevent intimate contact of specimento plate, which will appear as lighter areas. If this occurs,remove the specimen from the plate and repeat 7.1 to 7.6.7.8 Gloss readings may be ta
15、ken in accordance with TestMethod D 523.8. Keywords8.1 gloss; membrane switch; plastics, translucent; plastics,transparentASTM 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 expre
16、ssly 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 must be reviewed every five years andif not revised
17、, 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 theresponsible technical committee, which you may a
18、ttend. 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 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).F 1843 97 (2002)2
