1、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 followin
2、g 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.This standard has been approved
3、 for use by agencies of the Department of Defense.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
4、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 simulatevary
5、ing 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 thes
6、afety 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 a
7、nd 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 Di
8、ctionary 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 perfec
9、t, 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 permanentlypla
10、ne 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. A brass block in the form ofa rectangular parallelepiped 1.25 in. in width by 1.75 in. i
11、nlength 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.
12、 (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
13、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 Subcommi
14、ttee 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
15、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
16、, 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.NOTE 1If the test temperature used is higher than the softening pointof the coating, material such as wax may soak into the
17、 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 chl
18、oride to obtain approximately 75 % relative humid-ity and cp potassium carbonate to obtain approximately 44 %relative humidity.9. Procedure9.1 Bring the apparatus, including the desiccator containingthe proper salt solution, and the pressure surfaces after assem-bly, to the test temperature by heati
19、ng it for at least1hinthetest oven which previously has been adjusted to the desiredtemperature. When the desiccator is warmed, momentarilyopen its lid or open the cover stopcock to equalize pressure fora few minutes and then close the lid until the specimens areready for insertion.9.2 Stack the con
20、ditioned test specimens and pressure mediaon the shelf of the desiccator in the following sequence:Bottom plate 4 by 4 in. (102 by 102 mm),Interleaving paper or foil,Four test specimens,Interleaving paper or foil,Four test specimens, andPressure block.Stack specimens having faces of different charac
21、ters so thatthe three possible surface combinationsface to face, face toback, and back to backare tested. In this case, stack the twosets of four test specimens in the following sequence:Interleaving paper or foil,One specimen, face up (face to face),One specimen, face down (face to face),One specim
22、en, face down (face to back),One specimen, face up (back to back),Interleaving paper or foil, andPressure block.A desiccator 6 in. (152 mm) in diameter will permit foursamples to be tested in duplicate at one time. Locate each stackin a quarter section of the bottom plate so that individual stacksdo
23、 not overlap and so that the test areas are completelysupported by the bottom plate.9.3 Place the desiccator containing the assembled test stacksin the oven. Let the lid of the desiccator remain partially openor leave stopcock open to relieve pressure for 15 min; thenclose. Leave the desiccator in t
24、he oven at the desired tempera-ture for 21 6 1h.9.4 Take the desiccator from the oven, carefully remove thepressure blocks from the test stacks, and remove each stackfrom the desiccator. Gently lay down the stacks of testspecimens in the room (preferably at 73F (23C) and 50 %relative humidity) and l
25、et stand for 30 min. Examine byslipping or peeling the sheets apart, and rate the specimens forblocking resistance as follows:Degree of Block-ing Resistance Description of BlockingNo blocking No adhesion or cohesion between contiguous surfaceswhich slide freely upon one another. Surfaces ofspecimens
26、 are not marred when sheets are separ-ated.Slight blocking Slight adhesion. Adjacent surfaces do not slide freely,and upon separation of the sheets the surfaces showan occasional evidence of slight marring.ConsiderableblockingAdhesion or cohesion of contiguous surfaces. Layersmay be separated with d
27、ifficulty. Surfaces will bedefinitely marred or partially destroyed upon sep-aration.10. Report10.1 The report shall include the following:10.1.1 Name and type of material,10.1.2 Test conditions usedtemperature, relative humid-ity, and pressure, and10.1.3 Degree of blocking resistance, including a b
28、riefdescription of blocking found. If dissimilar surfaces exist onthe test specimen, report the blocking of the three possiblesurface combinations.11. Precision and Bias11.1 A precision statement is not appropriate for this testmethod since the test is comparative in nature and the resultsare subjec
29、tive and not numerical.12. Keywords12.1 blocking; blocking resistance; packaging papers; pa-per; paperboardTABLE 1 Test ConditionsDry-Bulb Temperature, F (C)RelativeHumidity, %Pressure, psi (kPa)100 6 2(386 1) 75 0.5 (3.4)120 6 2(496 1) 75 0.5 (3.4)140 6 2(606 1) 75 0.5 (3.4)100 6 2(386 1) 44 0.5 (3
30、.4)120 6 2(496 1) 44 0.5 (3.4)140 6 2(606 1) 44 0.5 (3.4)D 918 99 (2003)2ASTM 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 determination of the validity o
31、f 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 reapproved or withdrawn. Your comments a
32、re 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 feel that your comments have not re
33、ceived 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 918 99 (2003)3
