ASTMD5946-04

Designation:D 5946-04NTERNATIONALStandard Test Method forCorona-Treated Polymer Films Using Water Contact AngleMeasurements1This standard is issued under the fixed designation D5946;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.Scope*of a droplet using vanous projection or reflective devices and1.1 This test method covers measurement of the contactmeasuring the height and width on the substrate surface toangle of water droplets on corona-treated polymer film sur-calculate the contact angle as follows:faces.0=2·arc tan(H/R)(10)NorE 1-There is no similar or equivalent ISO standard.where:1.2 The values stated in SI units are to be regarded as the0 contact angle,standard.The values given in brackets are for information only.Hheight of a droplet's image,and1.3 This standard does not purport to address all of theRhalf its width.safety 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 618 Practice for Conditioning Plastics for TestingD 724 Test Method for Surface Wettability of Paper (Angle-of-Contact Method)E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 static contact angle,0 (degrees),n-the angle be-3.1.1.2 Discussion-Instrumentation is also available thattween the substrate surface and the tangent line drawn to theutilizes an image and directly determines the contact angledroplet surface at the three-phase point,when a liquid drop isbased on the calculation shown for Method(2)of U.S.Patentresting on a plane solid surface.No.5268.733.3.1.1.1 DiscussionContact angle values can be deter-3.1.1.3 Discussion-Method (1)may be biased due to themined as follows:(1)by analyzing an image of a droplet usingsubjective nature of visually fi nding a tangent to the dropletvarious projection or reflective devices and measuring theimage at the three-phase point;if Method (/is to be used,thecontact angle directly with a protractor by using tangentialbias of each operator's measurements shall be determined.alignment of a cursor line or the use of reference alignmentBecause Method (2)utilizes measured dimensions of theprocedures (Test Method D 724);or(2)by analyzing an imagedroplet,it would be expected to have less bias.Comparativeanalyses using these various procedures have not been con-ducted.Therefore,caution is recommended when comparingThis test method is under the jurisdiction ofASTM Committee D20 on Plasticsdata obtained from these different methods.and is the direct responsibility of Subcomm