1、Designation:D 2043 94(Reapproved 2002)An American National StandardStandard Test Method forSilver Tarnishing by Paper1This standard is issued under the fixed designation D 2043;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、 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 qualitative identification ofthe presence or absence of materials in paper that will tarni
3、shor stain silver which comes in contact with the paper.This testmethod is chiefly intended for testing tissue papers that are indirect contact with silver.The test results indicate the type oftarnish or stain and the relative distribution of the materialscausing such tarnishing or staining.NOTE1The
4、 main material in paper causing silver to tarnish or stain isreducible sulfur,which may be determined in accordance with TestMethod D 984.1.2 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 est
5、ablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,and Related Product2D 984 Test Methods for Reducible S
6、ulfur in Paper2D 1193 Specification for Reagent Water33.Summary of Test Method3.1 A specimen of the sample is saturated with water andplaced between two polished silver plates.The specimen isallowed to dry in contact with the plates at a temperature of70C for at least 3 h.At the end of the drying pe
7、riod,the platesare examined for evidence of tarnish or stain.3.2 Water repellent or parchmentized papers and metal-coated papers will require certain modifications of the testprocedure.In most cases,they may be tested without wettingthe test specimen and by prolonging the time in contact withthe sil
8、ver to at least 24 h.3.3 The principles involved in this test method are alsosuggested for use where wrapping paper is to be tested for itsstaining or corrosion properties with respect to other metals,such as steel,copper,nickel,etc.In such cases,plates or formsof the particular metal or alloy in qu
9、estion shall be used inplace of silver plates.Other modifications may be required fora specific purpose.For example,in the case of a metal thatwould rust,such as steel,the paper obviously could not bewetted;it would be necessary instead to heat in an atmosphereof high humidity.3.4 Modifications to a
10、ccommodate paperboard are alsopossible.One such modification is described in the Appendix.4.Significance and Use4.1 This test method covers the determination of the pres-ence or absence of materials that will tarnish or stain silver inpaper used for wrapping silverware.Freedom from tarnishingsilver
11、is an important end user requirement of such papers.4.2 Possible modifications to other metals have specializedapplications in metal plating,graphic arts,and related areas.5.Apparatus5.1 Metal Surface,4solid silver or silver plated brass flatplates,approximately 15 by 15 cm(6 by 6 in.).Two plates ar
12、eneeded for each test and are probably sufficient for occasionaltests of paper.Several sets are necessary where frequent testingis desired.5.1.1 Solid Silver Plates,approximately 15 by 15 cm(6 by6 in.).5.1.2 Metal PlatesFlat plates approximately 15 by 15 cm(6 by 6 in.)from commercial rolled sheet br
13、ass 0.25 in.(6.35mm)thick.One face of each plate should be buffed smooth andas free as possible from tool marks,then plated with pure silverto a thickness of about 0.125 mm,buffed again,and plated withanother 0.125 mm of silver.In this way,a smooth continuouslayer of pure silver about 0.25 mm thick
14、will be obtained thatcan be cleaned and polished repeatedly.It is advisable to checkthe amount of silver by weighing the brass plates before andafter plating.A layer of silver 0.25 mm thick should weigh1This test method is under the jurisdiction of ASTM Committee D06 on Paperand Paper Products and i
15、s the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved April 15,1994.Published June 1994.Originallypublished as D 2043 64 T.Discontinued 1981 and reinstated 1990.2Annual Book of ASTM Standards,Vol 15.09.3Annual Book of ASTM Standards,Vol 11.01.4The metal surface r
16、equired is not a stock item in many laboratory supplyorganizations,however the solid silver plates in 5.1.1 may be obtained upon orderfrom some dealers in fine and precious metals.One such source is Hagstoz&Son,709 Sampson St.,Philadelphia,PA 19106,who can supply the plates in 5.1.1 inseveral thicknesses.There are other similar sources.The plates in 5.1.2 can beobtained by purchasing the brass plates as described and having them plated withsilver to the specification in 5.1.2 by a commercial sil
