ASTM_D_724_-_99_2003.pdf

Designation:D 724 99(Reapproved 2003)An American National StandardStandard Test Method forSurface Wettability of Paper(Angle-of-Contact Method)1This standard is issued under the fixed designation D 724;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 measures the angle of contact when adrop of liquid is applied to the surface of a specimen of paper.1.2 The measurement of both the initial angle of contact andthe angle of contact after a defined elapsed period of time maybe measured.1.3 A standard liquid(ink)for making measurements isdescribed.1.4 Other liquids including printing inks,writing inks,adhesives,oils,and coating materials may be used uponagreement of those involved in the testing being done.1.5 Two types of apparatus for measuring the contact angleusing the procedure in this test method are described.Addi-tional instruments that can perform the procedure in this testmethod may also provide equivalent results.A different proce-dure using an automated instrument for measuring angle ofcontact will be found in Test Method D 57251.6 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.7 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,or Related ProductsD 685 Practice for Conditioning Paper and Paper Productsfor TestingD 5725 Test Method for Surface Wettability and Absor-bency of Sheeted Materials Using an Automated ContactAngle TesterE 122 Practice for Choice of Sample Size to Estimate aMeasure of Quality for a Lot or Process2.2TAPPI Standard:TAPPI Test Method T 458 Surface wettability of paper(angle of contact method)33.Significance and Use3.1 This test method is useful in measuring the interactionof paper with liquids in a variety of applications.3.2 When using the standard ink described in this testmethod,the contact angle measured initially is often consid-ered a measure of the ruling quality of the paper.3.3 When using the same standard ink,the change in contactangle between the times specified in this test method,5 and 60s,is often considered a measure of writing quality of the paperwhen an aqueous ink is used.3.4 In many applications,a contact angle between 90 and100 degrees,when a paper is tested with the standard ink,indicates that the paper will be suitable for general activitieswhere water-based inks are used.3.5 When this test method is used with specific non-standard inks of interest,or non-aqueous liquids,the users mustagree in advance the data to be collected and how the data willbe used.3.6 Additional suggestions for more specific use of this testmethod will be found in Section 10.4.Apparatus4.1 Drop Projection InstrumentAn instrument capable ofprojecting the image of a drop of liquid on the surface of paperonto a screen so that the angle of a line tangent with the dropat the paper surface can be measured.The general concept isshown in Fig.1 and shall consist of the following:NOTE1While the projection instrument illustrated and described isantiquated,it describes the concept of the measuring procedure.Instru-ments are available in a more convenient form that serve the samepurpose,that is projecting the image of the drop on a screen.4.1.1 Angle Measuring DeviceA protractor or similardevice for measurement of contact angle.4.1.2 Filter,used to reduce the heat on the specimen anddrop.1This 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 Feb.10,1999.Published May 1999.Originallypublished as D 724 43.Last previous edition D 724 94.2For 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,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.4.1.3 LampA ventilated lamp house containing a lightsource.4.1.4 MicroscopeA microscope draw tube suitable forprojecting the image of the drop on a screen with an enlarge-ment of 25 to 30 times.4.1.5 ScreenA frosted glass screen on which the drop isprojected is required.4.1.6