ASTM_D_7271_-_06_2012.pdf

Designation:D727106(Reapproved 2012)Standard Test Method forViscoelastic Properties of Paste Ink Vehicle Using anOscillatory Rheometer1This standard is issued under the fixed designation D7271;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 the procedure for determiningthe viscoelastic properties of printing ink vehicles by measur-ing the G,G”,and tan delta using a controlled strain cone andplate oscillatory rheometer.1.2 This test method provides the flexibility of using severaldifferent types of rheometers to determine viscoelastic proper-ties in ink vehicles.1.3 This test method is not intended for systems that arevolatile at procedure temperatures as evaporation may occureffectively changing the percent solids before testing is finishedand significantly altering the rheology.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 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:2E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions:33.1.1 frequency sweep test,nmost rheometers have pro-grams specific for their instrument.3.1.1.1 DiscussionThe user provides a specified geometry,frequency range,strain%or oscillatory stress and temperatureof the test.This test will produce the data required for thismethod.3.1.2 G,nthe elastic(storage)modulus obtained from anoscillatory test represents the energy stored during each fre-quency cycle,where the stress is divided by the correspondinglinear elastic strain.3.1.3 G”,nthe viscous(loss)modulus obtained from anoscillatory test represents the amount of energy lost duringeach frequency cycle or the imaginary part of the complexmodulus(for shear).3.1.4 geometry,nthe cone used in the test.3.1.5 shear strain,nrelative deformation in shear;termoften abbreviated to shear.3.1.6 shear stress,nthe component of stress parallel to(tangential to)the area considered.3.1.7 strain,nthe measurement of deformation relative toa reference configuration.3.1.8 tan delta(d),nthe ratio of G”(viscous modulus)toG(elastic modulus).3.1.9 viscoelasticity,nthe phenomena exhibited by a liq-uid when energy is applied and once the force is released,theliquid recovers towards its original state by means of storedenergy.4.Summary of Test Method4.1 Apply the ink vehicle to the plate of a rheometer.4.2 Select the geometry(cone)and set to the required gap tothe plate.4.3 Remove the excess vehicle with the ink spatula.4.4 Set the required temperature,strain or stress and fre-quency range for the frequency sweep.(Most rheometers havea test sequence that can be pre-prepared.)4.5 Allow five minutes for temperature calibration and thevehicle to relax to its lowest energy state.NOTE1Do not run a pre-shear sequence as this may affect results.4.6 Start the frequency sweep test.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.37 on Ink VehiclesCurrent edition approved June 1,2012.Published August 2012.Originallyapproved in 2006.Last previous edition approved in 2006 as D7271 06.DOI:10.1520/D7271-06R12.2For 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.3Many of the definitions came wholly or in part from“An Introduction toRheology,”H.A.Barnes,J.F.Hutton,and K.Walters,Elesevier,1989.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Significance and Use5.1 This test method has found acceptance in the litho-graphic ink industry in predicting rheological behavior of avehicle under press conditions caused by extrusion,shear-thinning rollers and dot gain recovery.5.2 This test method is restricted within the torque limita-tions and strain resolution of the rheometer used.5.3 Results may not be reproducible if the vehicle is nothomogenous.6.Apparatus6.1 Oscillatory Rheometer,capable of over 400 Newtons offorce,running at the required frequency range,and controllingstrain in the 5 to 10%range,as well as computer and softwarecapable of running this test.6.2 Cone,preferably two cm and 2(if the viscosity of thevehicle is too high for this geometry,other geometries may beused by agreem