ASTM_D_1223_-_93_1998.pdf

Designation:D 1223 93(Reapproved 1998)An American National StandardStandard Test Method forSpecular Gloss of Paper and Paperboard at 751This standard is issued under the fixed designation D 1223;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 is for measuring the specular gloss ofpaper at 75(15 from the plane of paper).1.2 Although its chief application is to coated papers(1),2this test method may also be used for uncoated papers.1.3 This test method is not a measure of image-reflectingquality and should not be used for cast-coated,lacquered,highly varnished(2,3,4)or waxed papers(5),and high-glossink films(6).For these purposes,TAPPI T 653“Specular Glossof Paper and Paperboard at 20 Degrees”is preferred,althoughthe present method has been shown to be suitable for glossmeasurements of most other ink films on paper or paperboard.Here,differences in the color and the diffuse reflectances ofthese ink films have a negligible effect on measured gloss.Forexample,on comparing white and black surfaces which areotherwise identical,the white surface will measure less thanone gloss unit higher than the black.1.4 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:D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,or Related Products3D 685 Practice of Conditioning Paper and Paper Productsfor Testing32.2TAPPI Standard:T 1200 Interlaboratory evaluation of test methods to deter-mine TAPPI repeatability and reproducibility43.Significance and Use3.1 This test method is widely used as a partial measure ofthe surface quality and shiny appearance of coated paper.4.Apparatus4.1 Gloss Meter(see Fig.1).It consists of a source oflight,a lens giving a converging beam of rays incident on thetest specimen,a suction plate to hold the specimen flat,and alight detector to receive and measure certain of the raysreflected by the test specimen.These components are com-bined in a light tight housing that is matte black inside and isstructurally and optically stable during warming and at theoperating temperature.Details of the geometric,spectral,andphotometric characteristics of the instrument and of the speci-men holder are given in Annex A1.4.1.1 Area of Specimen IlluminatedThe area illuminatedis controlled by the dimensions of the aperture stop A-Aspecified in Fig.1.If the outline of this spot is projectedsharply onto the specimen,the illuminated area will berectangular,0.10d 6 0.01d wide and 0.05 6 0.005d times1/cos 75 long.When the value for d is 100 mm,theilluminated spot will have a width between 9.0 and 11.0 mm,and length between 17.4 and 21.3 mm,resulting in anilluminated area between 156 and 234 mm2.On the assumptionthat approximately 2000 mm2of paper or board should beevaluated to obtain a representative gloss value for the sample,10 separate sheets or 10 different areas on one sheet should bemeasured and averaged.NOTE1No minimum value for d is specified since none is requiredwhen a sufficient number of measurements is made so that the averageprovides a gloss value representative of 2000 mm2of sample.4.2 Gloss StandardsThe theoretical specular-gloss stan-dard is an ideal,completely reflecting,plane mirror having anassigned value of 384.4 gloss units.A flat,clean,and polishedsurface of black glass having a refractive index of 1.540 for theSodium D line may be shown by the Fresnel equation(7)tomeasure 100 gloss units on this scale.4.2.1 High-Gloss Working Standard,a clean plaque ofpolished black glass for which the 75 specular reflectance hasbeen computed from its refractive index as measured for thesodium D line.1This test method is under the jurisdiction of ASTM Committee D-6 on Paperand Paper Products and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved Oct.15,1993.Published December 1993.Originallypublished as D 1223 55T.Last previous edition D 1223 92.2The boldface numbers in parentheses refer to the list of references at the end ofthis test method.3Annual Book of ASTM Standards,Vol 15.09.4Available from the Technical Association of the Pulp and Paper Industry,Technology Park/Atlanta,P.O.Box 105113,Atlanta,GA 30348.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.4.2.2 Intermediate-Gloss Standards,having a reflected fluxdistribution comparable with that of the paper to be tested.Such standards may consist of ceramic tiles which are flatenough so that they do not