ASTM_D_2979_-_16.pdf

Designation:D297916Standard Test Method forPressure-Sensitive Tack of Adhesives Using an InvertedProbe Machine1This standard is issued under the fixed designation D2979;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()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers measurement of the pressure-sensitive tack of adhesives.This test method is applicable tothose adhesives which form a bond of measurable strengthrapidly upon contact with another surface and which can beremoved from that surface cleanly,that is,without leaving aresidue visible to the eye.For such adhesives,tack may bemeasured as the force required to separate an adhesive and theadherend at the interface shortly after they have been broughtinto contact under a defined load of known duration at aspecified temperature.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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:2D907 Terminology of AdhesivesE4 Practices for Force Verification of Testing MachinesE171 Practice for Conditioning and Testing Flexible BarrierPackaging3.Terminology3.1 DefinitionsMany terms in this test method are definedin Terminology D907.4.Summary of Test Method4.1 This test method involves bringing the tip of a cleanedprobe of defined surface roughness into contact with theadhesive at a controlled rate,under a fixed pressure,for a shorttime,at a given temperature;and subsequently breaking thebond formed between the probe and adhesive,also at acontrolled rate.Tack is measured as the maximum forcerequired in breaking the adhesive bond.5.Significance and Use5.1 This test method provides a quantitative measure of thepressure-sensitive tack of the adhesive.5.2 The method is designed for the adhesive mass itself andis suitable for measuring the tack of pressure-sensitive adhe-sives for use on both rigid and flexible backings.5.3 This test method is suitable for quality control andresearch purposes.6.Apparatus6.1 ProbeA Type 304 stainless steel rod,5.0 mm(0.197 in.)in diameter,machined at one end of 90 to thelongitudinal axis.The tip is finished to a surface roughness ofnot more than 500 or less than 250 nm(20 to 10 in.)rms asmeasured by a surface-measuring device.3NOTE1When the adhesive is supported on flexible backings,or isgreater than 0.25 mm(0.010 in.)thick,a probe with a spherical crown of0.05 mm(0.002 in.)high,and with a 62.5-mm(2.5-in.)radius may beused.6.2 Pressure-Loading WeightAn annular ring whose in-side diameter is slightly larger than the probe diameter.Thering weight is such that the pressure applied to the sample is9.79 6 0.10 kPa(1.42 psi).NOTE2Contact pressures of 0.98,1.96,or 4.90 kPa(0.14,0.28 or0.71 psi)may be obtained by employing annuli of different weight.Theselower pressures as well as ones of 98 kPa(14.2 psi)or higher can be usedto show the effect of pressure directly when tack is pressure-dependent.6.3 Force GageA spring device with an indicator thatretains the maximum force reading until reset manually.The1This test method is under the jurisdiction of ASTM Committee D10 onPackaging and is the direct responsibility of Subcommittee D10.14 on Tape andLabels.Current edition approved Oct.1,2016.Published November 2016.Originallyapproved in 1971.Last previous edition approved in 2009 as D2979 01(2009).DOI:10.1520/D2979-16.2For 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.3An example of a suitable surface-measuring device is a Surfindicator manu-factured by Gould,Inc.,Gage and Control Div.,4601 Arden Dr.,El Monte,CA.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 spring characteristics is such that between 8.9 and 22.2 N(2and 5 lb)are required to extend it the permissible 2.5 mm(0.10in.).Mount the probe directly on the force gage.NOTE3Other force-measuring devices such as strain gage load cells,or devices with different force-deflection characteristics may be used incertain instances.Tack values obtained with these devices will differ inmagnitude but will be related to standard values obtained with thespecified gage.6.4 Testing MachineAmechanical system for bringing theadhesive into contact with the probe,automatically controllingthe dwell time during which the adhesive and probe are incontact under pressure,