1、Designation:D 895 94Standard Test Method forWater Vapor Permeability of Packages1This standard is issued under the fixed designation D 895;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 parenthe
2、ses 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 determination of the watervapor permeability of finished packages when closed andsealed in the conventional manner.This test met
3、hod is intendedfor“shelf-size packages”which are shipped in outside contain-ers.1.2 This test method may be applied to the package aspacked,after one or more performance tests such as drop(TestMethod D 5276),drum(Method D 782),vibration(MethodD 999),after a series of tests simulating the shipping en
4、viron-ment(Practice D 4169),or after shipping tests have beencompleted,as required.1.3 Packages with body walls having the property of ab-sorbing water are not suitable for testing under this testmethod.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with it
5、s 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.1.5 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information o
6、nly.2.Referenced Documents2.1 ASTM Standards:D 782 Test Method for Shipping Containers in RevolvingHexagonal Drum2D 996 Terminology of Packaging and Distribution Environ-ments2D 999 Methods for Vibration Testing of Shipping Contain-ers2D 1251 Test Method for Water Vapor Permeability of Pack-ages by
7、Cycle Method2D 4169 Practice for Performance Testing of Shipping Con-tainers and Systems2D 5276 Test Method for Drop Test of Loaded Containers byFree Fall23.Terminology3.1 DefinitionsGeneral terms for packaging and distribu-tion environments are found in Terminology D 996.3.2 Definitions of Terms Sp
8、ecific to This Standard:3.2.1 water vapor permeabilityof a package,the rate atwhich water is transmitted into the package from the testatmosphere surrounding it while a desiccant is sealed within.4.Significance and Use4.1 This test method is normally used to:4.1.1 Evaluate materials and construction
9、s for a specifictype of package,4.1.2 Compare performance of different types of packages,4.1.3 Determine adequacy of protection for a specific prod-uct or application,and4.1.4 Maintain quality control.4.2 When this test method is conducted to determine thewater vapor permeability of the packages for
10、 research,devel-opment,manufacturing control,specification acceptance,etc.,a desiccant is used as the water-absorbing medium.4.3 When this test method is used to determine the suitabil-ity of the package with respect to water vapor resistance for aparticular product,the product is used instead of th
11、e desiccant.5.Apparatus5.1 Weighing BalanceA suitable laboratory balance sen-sitive to 1 mg or one ten-thousandth of the mass of thepackage,whichever is larger.5.2 Test ChamberA test room or cabinet provided withconditioned air which is continuously circulated around thespecimens under test.The cond
12、itions in the chamber shall be386 2C(100 6 4F)and 90 6 2%relative humidity or asotherwise specified.The conditions in the chamber shall besuch that no condensation occurs on the specimens.6.Materials6.1 DesiccantA desiccant shall be used that has a highaffinity for water vapor and a high drying effi
13、ciency;that is,having a low water vapor pressure even after absorbing a largeamount of water.NOTE1Asuitable desiccant is anhydrous calcium chloride(CaCl2)inthe form of small lumps that will pass a No.8(2.36-mm)sieve,and freeof fines that will pass a No.30(600-m)sieve.6.2 ProductWhen the test is made
14、 to determine thesuitability of a specific package for a particular product,thatproduct may be used inside the test specimen instead of thedesiccant,in which case the specimen shall be filled to normalcapacity.1This test method is under the jurisdiction of ASTM Committee D-10 onPackaging and is the
15、direct responsibility of Subcommittee D10.23 on NaturalEnvironment Test Methods.Current edition approved May 15,1994.Published July 1994.Originallypublished as D 895 47 T.Last previous edition D 895 79(1984).2Annual Book of ASTM Standards,Vol 15.09.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr
16、 Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMNOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.7.Test Specimens7.1 Test specimens shall be representative of the packagesbeing tested,and shall be closed and sealed in the normalmanner.7.2 Performance shall be based on tests of a sufficientnumber of representative specimens of a given
