1、Designation:D404010Standard Test Method forRheological Properties of Paste Printing and Vehicles by theFalling-Rod Viscometer1This standard is issued under the fixed designation D4040;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,t
2、he 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.Scope*1.1 This test method covers the procedure for determiningthe falling-rod viscosity and degree of non-Newtonian beha
3、v-ior of printing inks,vehicles,and similar liquids that areessentially nonvolatile and unreactive under ordinary roomconditions.1.2 For printing inks,which are typically non-Newtonian,this test method is applicable in the apparent viscosity rangefrom about 10 to 300 P at a shear rate of 2500 s1.For
4、Newtonian liquids,the applicable viscosity range is about 10 to1000 P(1 P=0.1 Pas).1.3 This test method uses a falling-rod viscometer in whichshear conditions are altered by manually adding weight to therod.A fully automatic instrument is described in Test MethodD6606.1.4 This test method,as does Te
5、st Method D6606,basescalculations on the power law model of viscosity.ISO 12644covers not only the power law but also the Casson andBingham models.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 This standard does not pur
6、port 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.For specific hazardstatements,see Section 8.2.Re
7、ferenced Documents2.1 ASTM Standards:2D445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids(and Calculation of Dynamic Viscos-ity)D6606 Test Method for Viscosity and Yield of Vehicles andVarnishes by the Duke Viscometer2.2 Other Standards:ISO 12644 Graphic TechnologyDetermination
8、 of rheo-logical properties of paste inks and vehicles by the fallingrod viscometer3.Terminology3.1 Definitions:3.1.1 apparent viscosity,VD,nthe viscosity of a non-Newtonian fluid at a particular shear rate D.3.1.1.1 DiscussionAshear rate of 2500 s1has been founduseful for printing inks and is speci
9、fied in this test method.3.1.2 Newtonian,adjrefers to a liquid whose viscosity isconstant at all shear rates.3.1.3 non-Newtonian,adjrefers to a liquid whose viscos-ity varies with shear rate.3.1.3.1 DiscussionNon-Newtonain liquids may be eithershear-thinning(pseudoplastic)or shear-thickening(dilatan
10、t).Most printing inks are shear-thinning.3.1.4 shear rate,D,nvelocity gradient through thestressed liquid;the unit is 1/s or 1 s1.3.1.4.1 DiscussionIn the falling-rod viscometer,shear rateis inversely proportional to fall time F per unit distance L overwhich a unit thickness x of the liquid is stres
11、sed:D=L/xF.3.1.5 shear stress,S,nshearing force per unit area;theunit is 1 g/cms2(1 dyne/cm2).3.1.5.1 DiscussionIn the falling-rod viscometer,shearstress is proportional to total weight W per unit of shearing areaA times the gravitational constant g,in accordance with theequation:S=Wg/A.3.1.6 viscos
12、ity,V,nthe ratio of shear stress to shear rate.3.1.6.1 DiscussionThe viscosity of a liquid is a measureof the internal friction of the liquid in motion.The cgs unit ofviscosity is 1 g/cms(1 dynes/cm2)and is called a poise.TheSI unit is 1 Ns/cm2and is equal to 10 P.3.1.7 yield stress,So,nthe minimum
13、shear stress requiredto initiate motion in a non-Newtonian liquid.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applicationsand is the direct responsibility ofSubcommittee D01.56 on Printing Inks.Current edition approved Feb.1,2010.Publi
14、shed April 2010.Originallyapproved in 1981.Last previous edition approved in 2005 as D4040 05.DOI:10.1520/D4040-10.2For 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 st
15、andards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2 Definitions of Terms Specific to This Standard:3.2.1 Lehman yield value,
16、ncalculated yield stress basedon the Lehman chart.3.2.2 power law,na mathematical model that presumesthat the viscosity of a liquid varies with shear rate in accor-dance with a power function as follows:k 5SDN(1)where:k=a constant related to the viscosity of the liquid andN=a constant describing the rate at which shear stressvaries with shear rate.3.2.2.1 DiscussionThe value of N is precisely 1.0 for aNewtonian fluid,less than 1.0 for a shear-thinning liquid,andgreater than 1.0 for a shear-thick
