ASTM_D_814_-_95_2014.pdf

Designation:D81495(Reapproved 2014)Standard Test Method forRubber PropertyVapor Transmission of Volatile Liquids1This standard is issued under the fixed designation D814;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of the rate ofvapor transmission of volatile liquids through a rubber sheet,disk,or diaphragm.1.2 The values stated in SI units are to be regarded as thestandard.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.Referenced Documents2.1 ASTM Standards:2D3767 Practice for RubberMeasurement of Dimensions3.Significance and Use3.1 The rate of transmission of a liquid through a rubbersheet,that acts as a barrier,is important in rubber diaphragmperformance and other similar industrial applications.Thistransmission is referred to as vapor transmission since theliquid diffuses through the rubber in a molecular sense andescapes into free atmosphere in vapor form.3.2 This test method is applicable only to the materials insheet form of moderate thickness and is principally useful forcomparing the relative vapor transmission of different liquidsin the same rubber or of the same liquid through differentrubbers.Comparisons should not be made in which bothdifferent rubbers and different liquids are used.4.Apparatus4.1 The test apparatus shall consist essentially of glassvapor transmission jars(4.2)for each liquid,on which the testspecimens are mounted,and a suitable rack for supporting thejars in an inverted position in such a way as to allow freecirculation of air over the surface of the specimen.Theapparatus shall be kept in a constant temperature cabinet orroom at 23 6 2C(73.4 6 3.6F).4.2 Vapor Transmission JarA glass jar of approximately236-cm3(12-pt)capacity with an opening of 60.3 6 0.4 mm(2.375 6 0.015 in.)in inside diameter and a wall 3.2 mm(0.125 in.)in thickness at the opening,which shall be groundflat without rounded edges to a smooth ground-glass finish atthe contact surface.The opening shall be equipped with a metalscrew ring clamp holding a smooth-edged,flat,sheet-metalring 55.6 6 0.4 mm(2.188 6 0.015 in.)in inside diameter andapproximately 68.3 mm(2.69 in.)in outside diameter.The ringclamp and ring serve as a clamping device for holding thespecimen against the ground-glass-edge of the jar with acircular specimen area 55.6 mm(2.188 in.)in diameterexposed to the air while permitting the screw clamp to betightened to form a leak-proof seal without subjecting thespecimen to torsional strain.When testing extensible materials,a circular disk of 16 to 20-mesh screen shall be placed insidethe screw ring clamp between it and the flat metal ring toprevent stretching of the specimen during the test.The screendisk may be soldered in place on top of the sheet metal ring ifdesired.NOTE1A suitable vapor transmission jar may be prepared from a12-pt Mason jar equipped with a Kerr-type screw cap,provided the edgeof the jar is properly ground and finished with fine emery and the cap iscut with smooth,flattened edges to form the required circular opening.4.3 Dial MicrometerThe dial micrometer shall conform tothe requirements of Method A of Practice D3767.4.4 BalanceThe balance shall be of suitable capacitycapable of weighing to 0.005 g.5.Test Specimen5.1 The test specimens shall consist of circular disks 68 mm(2.69 in.)in diameter,cut with a sharp-edged die from a sheetof the material being tested.The thickness of the sheet,whichshall not exceed 3.2 mm(0.125 in.),shall be measured usingthe dial micrometer described in 4.3.5.2 For evaluating the vapor transmission of a particularliquid with respect to a given rubber,three specimens havingthe same nominal thickness within a tolerance of 63%shallbe tested.The vapor transmission of the liquid shall be taken as1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.10 on Physical Testing.Current edition approved Nov.1,2014.Published December 2014.Originallyapproved in 1944.Last previous edition approved in 2010 as D814 95(2010).DOI:10.1520/D0814-95R14.2For 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 website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 the average of the values obtained from the two rubberspecimens giving the lowest results,p