ASTM_D_7395_-_07_2012.pdf

Designation:D739507(Reapproved 2012)Standard Test Method forCone/Plate Viscosity at a 500 s-1Shear Rate1This standard is issued under the fixed designation D7395;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 determination of the viscos-ity of paints and related products using a cone/plate viscometerat a shear rate of 500 s-1.1.2 Viscosity values obtained by this method may be used asan alternative to results from No.4 Ford cup measurements.The values from this method do not replicate Ford cup results,but can be used for quality control,producer-user specifica-tions and viscosity reduction in the same manner that Ford cupsare used.1.3 If viscosity at a higher shear rate is needed,Test MethodD4287,which describes viscosity measurement at 10 000 to 12000 s-1may be used.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:2D3925 Practice for Sampling Liquid Paints and RelatedPigmented CoatingsD4287 Test Method for High-Shear Viscosity Using a Cone/Plate Viscometer3.Summary of Test Method3.1 The material to be tested is placed between the cone andplate of a cone/plate viscometer set at 25C,a solvent trap islowered,and the specimen is subjected to a shear rate of 500 s-1while the viscosity is measured.4.Significance and Use4.1 This test has been used to measure viscosities ofautomotive topcoats in place of No.4 Ford cup measurementsand has provided an equivalent ability to evaluate whether thepaint meets specifications and is sprayable.4.2 The method could be considered as an alternative to No.4 Ford cup and other efflux cup measurements for otherproducts as well.4.3 The type of viscometer described in this method givesbetter temperature control than Ford and other efflux cups andis expected to give better precision.4.4 This test method is suitable for all paints and relatedmaterials whether they are Newtonian in behavior or not.5.Apparatus5.1 Cone/Plate Type Viscometer with cone/speed combina-tion producing a shear rate of 500 s-1and fitted with a solventtrap that covers the cone.For automotive topcoats,the viscom-eter must provide a viscosity measurement range that includes20 to 200 cP(=mPa.s)at the above-mentioned shear rate.ABrookfield CAP1000+or CAP2000+with a#10 cone at 100rpm shaft speed has worked well.6.Reagents and Materials6.1 Water or SolventIf the viscometer allows manualzeroing,this should be done in accordance with the manufac-turers directions.Zeroing procedures that require liquids maybe satisfied with water or a low-viscosity solvent such asxylene or mineral spirits.6.2 Mineral OilsOne to three standard mineral oils withknown viscosities(certified by an approved laboratory)lyingbetween 10 and 90%full scale to be used for calibrating theinstrument.If a single oil is used,its viscosity should be similarto that of the materials being tested.NOTE1Silicone oils should be avoided because of their tendency tocontaminate instruments,containers and other equipment.7.Sampling7.1 Take a representative sample of the product to be testedin accordance with Practice D3925.If the sample has a1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.24 on Physical Properties of Liquid Paints&Paint Materials.Current edition approved Feb.1,2012.Published February 2012.Originallyapproved in 2007.Last previous edition approved in 2007 as D7395-07.DOI:10.1520/D7395-07R12.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 tendency to settle or separate on standing,then it must bestirred or shaken until homogeneous before a test specimen istaken from it.However,it is appropriate to directly test asample that has been under constant circulation and shear in apaint system.The specimen must be free of any foreign matteror air bubbles,and its volume must be sufficient to cover theportion of the viscometer plate under the cone when the latteris brought into contact with the plate.8.Preparation of Apparatus8.1 The viscometer must be zeroed on a daily basis o