ASTM_D_918_-_99_2003.pdf

Designation:D 918 99(Reapproved 2003)An American National StandardTechnical Association of Pulp and Paper IndustryStandard Method T 477 m-47Standard Test Method forBlocking Resistance of Paper and Paperboard1This standard is issued under the fixed designation D 918;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the block-ing resistance of flexible types of packaging materials,includ-ing paper,and the impregnated,coated or laminated,or coatedand laminated,combinations of paper with metallic foils andsynthetic films that may be produced therefrom,but is appli-cable to papers in general,whenever a tendency to block isimportant.The test method provides a range of standardconditions of temperature and relative humidity at constantpressure for a specified time which is designed to simulatevarying climatic conditions that may be encountered in themanufacture,storage,transportation,or use of the materials.1.2 The values stated in inch-pound units are to be regardedas the standard.The values in parentheses are for informationonly.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:2D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,and Related ProductsD 685 Practice for Conditioning Paper and Paper Productsfor TestingD 1968 Terminology Relating to Paper and Paper Products3.Terminology3.1 Definitions:Definitions shall be in accordance withTerminology D 1968 and the Dictionary of Paper.34.Apparatus4.1 OvenA constant-temperature oven that can be main-tained at selected temperatures between 100 and 140F(38 and67C)within 62F(1C).4.2 DesiccatorA desiccator,for use as humidity chamber,having a minimum diameter of 6 in.(152 mm).Ground-glassedges should be perfect,clean,and freshly lubricated withstopcock grease.A vacuum type is preferred with pressure-relieving stopcock in the cover.4.3 BedplatesFour 4 by 4-in.(102 by 102 mm)pieces ofplate glass or corrosion-resistant metal having flat uppersurfaces.4.4 Pressure BlocksFour blocks having permanentlyplane rectangular bottom surfaces 1.25 by 1.75 in.(32 by 44mm).Each pressure block shall weigh,or be loaded to weigh,17.5 6 0.2 oz(496 6 6 g)to yield a pressure of 0.5 psi(3.4kPa)on the underlying specimens.Abrass block in the form ofa rectangular parallelepiped 1.25 in.in width by 1.75 in.inlength by 1.625 in.(41.27 mm)in height will meet therequirements without loading.4.5 Interleaving MaterialInterleaving material of whitebond paper or metal foil.5.Sampling5.1 The material shall be sampled in accordance withPractice D 585.6.Test Specimens6.1 Eight test specimens 1.25 by 1.75 in.(32 by 44 mm)shall be cut from each sample for each set of test conditionsused.The specimens shall be cut from the sample in such a wayas to be representative.7.Conditioning7.1 The specimens shall be conditioned before testing inaccordance with Practice D 685.8.Test Conditions8.1 One or more of the sets of conditions given in Table 1shall be used.Selection of the proper conditions will dependupon the type of material tested and the actual conditions that1This test method is under the jurisdiction of ASTM Committee D06 on Paperand Paper Products and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved Dec.10,1999.Published January 2000.Originallyissued 1947.Replaces D918 47 T.Last previous edition D 918 81(1993)e1.2For 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.3Available from the Technical Association of the Pulp and Paper Industry,Box105113,Atlanta,GA 30348.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.are liable to arise during storage and use of the material.In anycase,the temperature selected shall be below the softeningpoint of the coating.NOTE1If the test temperature used is higher than the softening pointof the coating,material such as wax may soak into the base sheet and thusgive no adhesion.8.2 The desired relative humidity shall be obtained by usinga saturated salt solution of the proper salt in distilled water inthe presence of an excess of the solid phase.The solution shallbe placed in the base of the desiccator for this test,using cpsodium chloride to obtain approximately 75%relative humid-ity and cp potassium c