1、Designation: D 814 95 (Reapproved 2005)Standard Test Method forRubber PropertyVapor Transmission of Volatile Liquids1This standard is issued under the fixed designation D 814; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the yea
2、r 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 measurement of the rate ofvapor transmission of volatile liquids through a rubber sh
3、eet,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 practi
4、ces and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 3767 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 rub
5、ber 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 fo
6、rm 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
7、 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
8、 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 gro
9、undflat 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.
10、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 t
11、o 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 ifd
12、esired.NOTE 1A 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 Micromet
13、erThe dial micrometer shall conform tothe requirements of Method A of Practice D 3767.4.4 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
14、 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 nomin
15、al thickness within a tolerance of 63 % shallbe tested. The vapor transmission of the liquid shall be taken asthe average of the values obtained from the two rubberspecimens giving the lowest results, providing these checkwithin 620 % of the average so determined.1This test method is under the juris
16、diction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.10 on Physical Testing.Current edition approved May 1, 2005. Published May 2005. Originallyapproved in 1944. Last previous edition approved in 2000 as D 814 95 (2000).2For referenced ASTM standards, visit the
17、 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 Conshohocken, PA 19428-2959, U
18、nited States.6. Procedure6.1 With the vapor transmission jar in an upright position,place 200 cm3of the test liquid in it, after which fit the testspecimen over the mouth of the jar, place the ring and wirescreen in position, and screw down the screw ring clamplightly. Hold the assembly in the const
19、ant temperature cabinetor room at 23 6 2C (73.4 6 3.6F) with the test disk lightlyin place until temperature equilibrium is obtained. Then screwdown the ring tightly and allow the assembly to stand in anupright position for 2 h. Make a tare assembly using a duplicatejar and a test specimen of the sa
20、me size but without theaddition of the test liquid. Place suitable weighting materialsuch as lead shot in the tare jar to bring its mass to approxi-mately that of the assembled jar and contents. Condition thetare jar at the test temperature, seal it, and handle throughoutthe test in a manner similar
21、 to that used for the test jar. Placethe test jar on a balance of suitable capacity capable ofweighing to 0.005 g, and counterbalance it against the tare jar,adding weights as required for equilibrium. Take the originalmass of the test assembly as that of the tare corrected for theadded weights and
22、record to the nearest 0.005 g.6.2 After weighing, invert each test jar assembly and placeon the rack, supporting each in such a way that the entire innersurface of the specimen remains in contact with the liquidthroughout the test. If the rack is located in a conditioningcabinet, take care to remove
23、 diffused vapors from the chamberand to assure free circulation of fresh air by means of a fan orother suitable device. Twenty-four hours after inverting the jar,again weigh it against the tare jar. Any excessive loss of massindicates that leakage due to improper seal is occurring.Remove such test a
24、ssemblies and replace them by newassemblies properly prepared. Return the test assembly to therack and reweigh against the tare after periods of 120 6 2 h and192 6 2 h from the initial inversion. Consider the difference inmass between those obtained at 120 h (5 days) and at 192 h (8days) divided by
25、3 as the average mass of liquid lost per 24 h.NOTE 2In this test, the specimens are allowed to remain in contactwith the liquid for 5 days before starting measurement of the loss in orderto permit the rate of diffusion of the liquid to become uniform.7. Calculation7.1 Express the vapor transmission
26、rate (VTR) of each testliquid with respect to the rubber employed and calculate asfollows:Vapor transmission rate VTR!, mg/sm2! 5 4.773 average mass in grams of liquid lost per 24 h (1)8. Report8.1 The report shall include the following:8.1.1 Identification of the test rubber,8.1.2 Thickness of the
27、test rubber to the nearest 0.025 mm(0.001 in.),8.1.3 Identification of the test liquid, and8.1.4 Vapor transmission rate (VTR) of the liquid, expressedin milligrams per second per square metre of wetted area.9. Precision9.1 Due to a lack of laboratories willing to participate inround-robin testing,
28、no precision data are available for this testmethod.10. Keywords10.1 vapor transmission; volatile liquidsASTM 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
29、 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, either reapprov
30、ed 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 attend. If you fee
31、l 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).D 814 95 (2005)2
