流变学及方法论ppt课件

1A SEMINAR PRESENTED BY:Robert McGregor,Sales&Marketing Manager RHEOLOGY and METHODOLOGYISO 9001:2000 CERTIFIEDA SEMINAR PRESENTED BY:RHEOLOG12Engineering Laboratories,Inc.Middleboro,MA U.S.A.Engineering Laboratories,Inc.23ISO 9000 Certified Since 1993BROOKFIELD QUALITYProducts Conform to CEOver 200 employees involved in:-Engineering-Design-Manufacturing-Assembly-Quality Control-Technical SupportFamily/Employee OwnedISO 9000 Certified Since 1993B34INTRODUCTIONINTRODUCTION45解释流变学的基本原理和它们与粘度测量的关解释流变学的基本原理和它们与粘度测量的关系系对不同的仪器解决粘度测量问题提出实践的方对不同的仪器解决粘度测量问题提出实践的方法法概括出一些用来找出粘度数据与材料行为的相概括出一些用来找出粘度数据与材料行为的相关性的实践方法关性的实践方法目标目标解释流变学的基本原理和它们与粘度测量的关系目标56流变学是描述材料如何改变它们形状的科学流变学是描述材料如何改变它们形状的科学,对于液对于液体和半固体体和半固体,通常称为通常称为“流动行为流动行为”.粘度是流变学的一部分粘度是流变学的一部分,它被用来量化材料改变形状它被用来量化材料改变形状的阻力的阻力.流变学和粘度流变学和粘度流变学是描述材料如何改变它们形状的科学,对于液体和半固体,通67正确的解释粘度数据可以降低不合格率正确的解释粘度数据可以降低不合格率,同时使生产同时使生产和配方开发成本降到最低和配方开发成本降到最低.通过合适的粘度测量通过合适的粘度测量(单独单独的粘度测量或与其它方法结合的粘度测量或与其它方法结合)使得产品质量的一致使得产品质量的一致性得到了保证性得到了保证.为什么要测量粘度为什么要测量粘度?正确的解释粘度数据可以降低不合格率,同时使生产和配方开发成本78Material characterization or“finger-printing”Standard testing methods to check for differences between batchesIndirect way of measuring qualityProduct formulationQuality controlProcess controlDesign,optimization and operation of process equipment粘度测量数据的应用粘度测量数据的应用Material characterization or“89流变学简介流变学简介流变学简介910流体模型流体模型Stationary PlateMoveable PlateA=Area cm2A=Area cm2X=DistanceF=Force(dynes)V=Velocity流体模型Stationary PlateMoveable P1011剪切率剪切率(流动梯度流动梯度)假定假定:板的长度远大于板的间距。板的长度远大于板的间距。剪切率(流动梯度)假定:板的长度远大于板的间距。1112Reciprocal SecondInverse Secondsec-1 or s-1 or 1 sec剪切率术语剪切率术语Reciprocal SecondInverse Secon1213流变学及方法论ppt课件1314F(dynes)A(cm2)剪切力剪切力F(dynes)A(cm2)剪切力1415牛顿将粘度定义为所加应力与流动梯度的比例。流动牛顿将粘度定义为所加应力与流动梯度的比例。流动梯度是所加应力的结果。梯度是所加应力的结果。粘度方程粘度方程牛顿将粘度定义为所加应力与流动梯度的比例。流动梯度是所加应力1516National Institute of Science&Technology(NIST)将水的粘度定义为在将水的粘度定义为在20C 时用毛细管时用毛细管粘度计为粘度计为1.0019 cP。水的粘度水的粘度National Institute of Science 1617Glass100,000,000,000,000,000,000,000 cPBitumen1,000,000,000,000 cPPolymer Melt1,000,000 cPHoney10,000 cPGlycerol1,000 cPOlive Oil100 cPBaby Oil10 cPWater1 cPAir0.01 cP典型液体的大概粘度值典型液体的大概粘度值Glass100,000,000,000,000,000,1718剪切力剪切力(力力/单位单位)面积面积t=(dynes/cm2)剪切率剪切率(速度梯度速度梯度)V(cm/sec)X(cm)粘度粘度(剪切力剪切力/剪切率剪切率)h=方程方程VX(sec-1)=t(dynes/cm2)(sec-1)剪切力(力/单位)面积方程V(sec-1)=t(dyne18191 Poise(P)=1 dyne/cm2sec-11 Poise=100 centipoise1 Pascal second=1000 centipoise粘度单位粘度单位1 Poise(P)=1dyne/cm2粘度单位1920考虑考虑剪切率是流体中的速度梯度剪切率是流体中的速度梯度(流体在管、搅拌釜中流体在管、搅拌釜中流动流动,或沿倾斜表面向下滚动时的速度剖面分布图或沿倾斜表面向下滚动时的速度剖面分布图).流体中的剪切力来自于加在体系上的力流体中的剪切力来自于加在体系上的力(输入泵或输入泵或搅拌器的扭矩搅拌器的扭矩,刮刀的刮的行为刮刀的刮的行为,或储油罐的重力牵或储油罐的重力牵引力引力).在线应用在线应用考虑剪切率是流体中的速度梯度(流体在管、搅拌釜中流动,2021运动粘度运动粘度StokesCentistokes(mm2/sec)绝对粘度绝对粘度PoiseCentipoise(mPas)表观粘度表观粘度PoiseCentipoise(mPas)粘度的分类粘度的分类运动粘度绝对粘度表观粘度粘度的分类2122动态或旋转粘度动态或旋转粘度SI UnitsmPas“Millipascal seconds”CommoncP(Centipoise)Conversion1 cP=1 mPas运动粘度运动粘度SI Unitsmm2/sCommoncSt“Centistokes”Conversion1 mm2/s=1 cSt只需将运动粘度乘上重力就可以得到动态粘度只需将运动粘度乘上重力就可以得到动态粘度:cStx SG=cPmm2/s x SG=mPas这个关系式仅对牛顿流体成立。这个关系式仅对牛顿流体成立。国际标准和美国标准国际标准和美国标准动态或旋转粘度运动粘度只需将运动粘度乘上重力就可以得到动态粘2223根据牛顿法则，流体的粘度是恒定的，随着剪切率的根据牛顿法则，流体的粘度是恒定的，随着剪切率的变化，剪切力也随之成比例的变化来保持粘度的恒定变化，剪切力也随之成比例的变化来保持粘度的恒定常见的这种流体有常见的这种流体有:水水丙三醇丙三醇矿物油矿物油溶剂溶剂多数的流体并不遵从牛顿法则，因此，流体可以分为两多数的流体并不遵从牛顿法则，因此，流体可以分为两类类:牛顿流体牛顿流体非牛顿流体非牛顿流体牛顿法则牛顿法则根据牛顿法则，流体的粘度是恒定的，随着剪切率的变化，剪切力也2324此种流体在给定温度下一个很大的剪切率范围内有一个此种流体在给定温度下一个很大的剪切率范围内有一个固定的粘度，粘度与测量时的剪切率无关固定的粘度，粘度与测量时的剪切率无关.如果你在测量一个流体的粘度时发现在不同剪切率下其如果你在测量一个流体的粘度时发现在不同剪切率下其粘度是相同的粘度是相同的,则此材料在所测量的剪切率范围内是牛顿则此材料在所测量的剪切率范围内是牛顿流体流体.牛顿流体的流动牛顿流体的流动牛顿流体的流动2425流动曲线流动曲线流动曲线2526流体的行为可以通过剪切应力流体的行为可以通过剪切应力/剪切应率的图来表征。剪切应率的图来表征。流动曲线或流动曲线或“流变图流变图”可以提供以下直观的信息：流动可以提供以下直观的信息：流动的开始（屈服应力）、剪切应率的影响、剪切时间的影的开始（屈服应力）、剪切应率的影响、剪切时间的影响以及搅动或运动后的恢复。响以及搅动或运动后的恢复。流动曲线流动曲线流体的行为可以通过剪切应力/剪切应率的图来表征。流动曲线2627.液体的液体的 剪切应力剪切应力 和和 剪切剪切应率应率 的关系可以在图中的关系可以在图中直观的表示，图中直观的表示，图中Y轴为轴为t t，X轴为轴为 g g。这个图就。这个图就称为称为“流动曲线流动曲线”.流动曲线流动曲线.液体的 剪切应力 和 剪切应率 的关系可以在图中直观的表示2728牛顿流体的行为牛顿流体的行为 牛顿流体的行为2829对于对于非牛顿非牛顿 流体，粘度取决于测量时的剪切行为（剪流体，粘度取决于测量时的剪切行为（剪切应率或剪切应力）。切应率或剪切应力）。非牛顿流体非牛顿流体 的流动可以分为以下两类：的流动可以分为以下两类：时间不相关的流动时间不相关的流动时间相关的流动时间相关的流动时间相关性是指流体在剪切作用下受时间的影响。时间相关性是指流体在剪切作用下受时间的影响。非牛顿流体的流动非牛顿流体的流动对于非牛顿 流体，粘度取决于测量时的剪切行为（剪切应率或剪切2930非牛顿流体非牛顿流体,时间不相关行为时间不相关行为 非牛顿流体,时间不相关行为3031非牛顿流体非牛顿流体,时间不相关行为时间不相关行为 非牛顿流体,时间不相关行为3132非牛顿流体非牛顿流体,时间不相关行为时间不相关行为 非牛顿流体,时间不相关行为3233非牛顿流体非牛顿流体,时间相关行为时间相关行为触变性触变性 可以用来表明产品可以用来表明产品内部结构的破坏。内部结构的破坏。非牛顿流体,时间相关行为3334迟滞回环迟滞回环的面积可以表征的面积可以表征 触变性触变性的程度。的程度。非牛顿流体非牛顿流体,时间相关行为时间相关行为迟滞回环的面积可以表征 触变性的程度。非牛顿流体,时间相3435非牛顿流体非牛顿流体,时间相关行为时间相关行为非牛顿流体,时间相关行为3536非牛顿流体非牛顿流体,时间相关行为时间相关行为非牛顿流体,时间相关行为 3637需要了解的事实需要了解的事实所需测量的基本量有所需测量的基本量有:S S剪切应力剪切应力S S剪切应率剪切应率S S时间时间流动特性中的时间相关性经常会与剪切相关性混淆流动特性中的时间相关性经常会与剪切相关性混淆表征粘度最好的方法是定量描述在表征粘度最好的方法是定量描述在“已知条件已知条件”下下流动过程的变稀或变稠的程度流动过程的变稀或变稠的程度。流动现象的综述流动现象的综述需要了解的事实流动现象的综述3738描述非牛顿流体行为的四种术语的关系描述非牛顿流体行为的四种术语的关系描述非牛顿流体行为的四种术语的关系3839影响粘度的其它因素影响粘度的其它因素影响粘度的其它因素3940液体的粘度在一定程度上会随温度而变化液体的粘度在一定程度上会随温度而变化.除了一些特例外，大部分的液体都有负的粘度温除了一些特例外，大部分的液体都有负的粘度温度系数。对水而言，此系数为度系数。对水而言，此系数为-.08%/C，对于高，对于高粘度油则此系数可以高达粘度油则此系数可以高达-10%/C.粘度粘度VS.温度温度液体的粘度在一定程度上会随温度而变化.粘度VS.温度4041粘度粘度 VS.温度的分布图温度的分布图粘度 VS.温度的分布图4142压力压力 会压缩流体，从而增加分子间的阻力。会压缩流体，从而增加分子间的阻力。增大增大压力压力会增加粘度会增加粘度。粘度粘度 VS.压力压力压力的变化会引起压力的变化会引起:溶解气体，产生了气泡溶解气体，产生了气泡溶解气体，改变了大小和分布溶解气体，改变了大小和分布产生紊流产生紊流压力 会压缩流体，从而增加分子间的阻力。增大压力会增加粘度 4243流体在粘度测量前的情况会影响所得到的数据。流体在粘度测量前的情况会影响所得到的数据。粘度为时间相关性（触变性或震凝性）的材料在进行粘度为时间相关性（触变性或震凝性）的材料在进行粘度测量前的处理必须是仔细的和一致性的。测量时粘度测量前的处理必须是仔细的和一致性的。测量时的粘度将取决于此材料是如何被灌注、搅拌或混合的。的粘度将取决于此材料是如何被灌注、搅拌或混合的。材料的预处理材料的预处理流体在粘度测量前的情况会影响所得到的数据。材料的预处理4344粘度计的类型粘度计的类型粘度计的类型4445WAYS TO MEASURE VISCOSITYViscometry is basic to the solution of many problems in research,development,process engineering and quality control.The laws of physics related to viscosity analysis have long been established.There are still many instruments or methods in use which over-simplify these laws in the solution of viscosity problems.Misleading data and erroneous conclusions about material behavior can result.WAYS TO MEASURE VISCOSITYVisco4546An instrument used to measure viscosity senses resistance to fluid movement.The method for sensing may involve a direct measure of:Force(Torque)Displacement(Amplitude)Time(Frequency)Pressure DropSENSING PARAMETERSAn instrument used to measure 4647Moving Fluid MethodSEfflux CupsSCapillary TubesSRampsSensing ParameterSTimeSTime&Pressure DropSTime&DisplacementMoving Element MethodSLinearly MovingSVibrating ElementSRotating ElementVISCOSITY MEASUREMENT DEVICESSTimeSFrequency&AmplitudeSTorque,Displacement,TimeMoving Fluid MethodSensing Par4748MOVING FLUID-TIME BASEDMOVING FLUID-TIME BASED4849Single point measurementDensity is a factorShear rate changes as cup emptiesCannot evaluate flow propertiesEFFLUX CUP ISSUESSingle point measurementEFFLUX4950Efflux VesselEtched LinesReceiving VesselCAPILLARY TUBETUBEMOVING FLUID-TIME BASEDEfflux VesselReceiving VesselC5051Single point measurementDensity is a factorPrimarily used for low viscosity Newtonian fluidsClean upBreakageCAPILLARY ISSUESSingle point measurementCAPILL5152MOVING FLUID-TIME BASEDMOVING FLUID-TIME BASED5253Single point measurementShear rate changes as fluid flows down rampTemperature may vary due to lack of controlCannot evaluate flow propertiesRAMP ISSUESSingle point measurementRAMP I5354Efflux Cup ViscometerInexpensive but gives relative data only.Glass Capillary Tube ViscometerAn accurate test,but used for very thin liquids primarily.Ramp ViscometerInexpensive but gives relative data only.SUMMARYMOVING FLUID METHODSEfflux Cup ViscometerSUMMARYM5455OR.LINEAR MOVING ELEMENTOR.LINEAR MOVING ELEMENT5556LINEAR MOVING ELEMENTLINEAR MOVING ELEMENT5657Single point measurementDensity is a factorShear rate changes until element reaches steady-state velocityCannot evaluate flow propertiesLINEAR MOVINGELEMENT ISSUESSingle point measurementLINEAR5758Change in amplitude or frequency of oscillation is measured.VIBRATING ELEMENTChange in amplitude or frequen5859Single point measurementVibrational viscometers sense a thin layer of fluid at the surface of the sensor.The sensor is driven at a fixed frequency or amplitude and the power input is measured.Since the vibrating probe accelerates the fluid,power input is proportional to the product of viscosity and density.Cannot evaluate flow propertiesVIBRATING ELEMENT ISSUESSingle point measurementVIBRAT5960ROTATING ELEMENTROTATING ELEMENT6061lThe fluid is sheared between two surfaces,the rotating spindle and the chamber wall.lShear Rate is the rotational speed divided by the gap distance.lShear Stress is determined by measuring torque on the spindle.lViscosity can be precisely calculated.lVariable speed element can evaluate flow properties.ROTATING ELEMENT ISSUESThe fluid is sheared between t6162Linear Moving Element ViscometerViscosity is proportional to time.A very repeatable method,but cannot characterize flow properties.Vibrating Element ViscometerViscosity is proportional to oscillating amplitude or frequency.It gives fast test results,but the flow behavior cannot be measured.Rotating ElementViscosity is mathematically defined in absolute units by preset speed and measured torque.This provides accurate characterization of flow behavior.SUMMARYMOVING ELEMENT METHODSLinear Moving Element Viscomet6263THE BROOKFIELD VISCOMETER:PRINCIPLE OFOPERATIONTHE BROOKFIELD VISCOMETER:PRI6364BROOKFIELD DIAL READING VISCOMETERBROOKFIELD DIAL READING VISCOM6465VISCOMETER DIALVISCOMETER DIAL6566STANDARD BROOKFIELDTORQUE RANGESSFour Model Series:Dial&Digital(dyne-cm)LVRVHAHB673.77,18714,37457,496SOptional Torque Ranges Available:2.5XLV1/4XRV2XHA2XHB5XLV1/2XRV2.5XHA2.5XHB5XHBSComparison Between RV and HA With No.4 Spindle at 10 RPM,Fluid of 20,000 cP#4 RV 10 RPM%=50Torque=3594 Dyne-cm#4 HA 10 RPM%=25Torque=3594 Dyne-cmSTANDARD BROOKFIELDTORQUE RAN6667PIVOT SUPPORT ASSEMBLYSHAFT&BEARINGPIVOT SUPPORT ASSEMBLYSHAFT&6768BROOKFIELD VISCOMETER ROTATIONAL SPEEDSDial(and Digital DV-I and DV-II)LVF4 Speeds 6,12,30,60 RPMLVT8 Speeds 0.3,0.6,1.5,3,6,12,30,60 RPMRVF4 Speeds 2,4,10,20 RPMRVT/HAT/HBT8 Speeds 0.5,1.0,2.5,5,10,20,50,100 RPMDigital DV-I+and DV-II+18 Speeds 0.3,0.6,1.5,3,6,12,30,60 RPM0.5,1,2,2.5,4,5,10,20,50,100 RPMProgrammable DV-II+and DV-III/DV-III+DV-II+54 Speeds 0.01-200 RPM DV-III/DV-III+2,600 Speeds 0.01 to 250 RPM BROOKFIELD VISCOMETER ROTATION6869Instrument accuracy is 1%of maximum viscosity that can be measured with a specific spindle/speed combination.Max viscosity is also called“Full Scale Range”(FSR).Example:LVT Viscometer,LV-3 spindle,guard leg attached,600 ml beaker,30 RPM rotational speed.4,000 cP is the maximum viscosity that can be measured.40 cP=1%of the maximum viscosity or FSRBROOKFIELD MEASUREMENT ACCURACYInstrument accuracy is 1%of6970Push the Push the AUTORANGEAUTORANGE button on a digital viscometer button on a digital viscometer to find maximum viscosity.Calculate the 1%value.to find maximum viscosity.Calculate the 1%value.Factor on Brookfield Factor Finder=1%of max Factor on Brookfield Factor Finder=1%of max viscosityviscosityTable in Table in“More Solutions to Sticky Problems”“More Solutions to Sticky Problems”Formula in Operator ManualFormula in Operator ManualACCURACY CALCULATION SHORTCUTSPush the AUTORANGE button on a7071CALIBRATIONCALIBRATION71721%of the viscosity specified on the labelExample:Fluid 1,000 has actual viscosity 980 cP at 25C 9.8 cP=1%of 980 cPVISCOSITY STANDARD FLUID ACCURACY1%of the viscosity specified7273Requires both the 1%accuracy error calculation for the Viscometer and the viscosity standard fluid.ALLOWABLE ERROR FOR CALIBRATION CHECKRequires both the 1%accurac7374RV-5 with 5,120 cP Fluid rpmfactorminmaxcPcP%reading+/-FSRtorquecP 10400400040,00012.95160451RV-5 with 5,120 cP Fluid rpmf7475RV-5 with 5,120 cP Fluid rpmfactorminmaxcPcP%reading+/-FSRtorquecP 20200200020,00025.75140251 10400400040,00012.95160451RV-5 with 5,120 cP Fluid rpmf7576RV-5 with 5,120 cP Fluid rpmfactorminmaxcPcP%reading+/-FSRtorquecP50808008,00064.25136131 6200200020,00025.15000251 3400400040,00012.34920451RV-5 with 5,120 cP Fluid rpmf7677SPINDLE GEOMETRYSPINDLE GEOMETRY7778DISC SPINDLESDISC SPINDLES7879CYLINDRICAL SPINDLESCYLINDRICAL SPINDLES7980Side length to diameter ratios of at least 2.5 to 1Shear rate depends on rotational speed and distance to chamber/container wallSample sizes are generally 100 ml or greaterApplications include:S S LiquidsS S Semi-solidsCYLINDRICAL SPINDLESSide length to diameter ratios8081COAXIAL CYLINDER GEOMETRYCOAXIAL CYLINDER GEOMETRY8182Coaxial cylinder geometryOriginally designed to measure small samples of precious materials.Shear rate range of 0.022 to 330 sec-1Viscosity range from 1.2 cP(mPas)to 1 x 108 cP(mPas)Temperature to 100CSample sizes from 2 mL to 16 mLApplications include:S S Casson viscosity of chocolate S S Thick film ink S S Shampoo S S Paint S S Printing Ink VarnishSMALL SAMPLE ADAPTERCoaxial cylinder geometryOrig8283Coaxial cylinder geometryOriginally designed to measure hot melt adhesives and wax coating material.Specified by ASTM D3236Shear rate range of 0.022 to 330 sec-1 Viscosity range from 1.2 cP(mPas)to 400 x 106 cP(mPas)Sample sizes from 8 mL to 13 mLTemperature to 300CApplications include:S S Hot Melt Adhesives S S Coating Materials S S Asphalt/Pitch/Carbon Fines S S Candy Base S S Cable CompoundsTHERMOSELCoaxial cylinder geometryOrig8384lCoaxial cylinder geometryDesigned to expand the lower measurement range of viscometerslShear rate range of 0.12 to 306 sec-1lViscosity range from 1cP(mPas)to 2,000 cP(mPas)lTemperature to 100ClSample size:S Closed Tube 16 mLSOpen Tube vessel immersionlApplications include:SOilsSSlurriesS Polymer in solventSInk Jet inksU.L.ADAPTERCoaxial cylinder geometryDesi8485Helical flow patternOriginally designed for use with T-Bar spindles for measuring fluids that have slow flow rates and exhibit“channeling”.Shear rate ranges are not definedViscosity/consistency ranges to 800 x 106 cP(mPas)Temperature to 300CSample sizes 100 mL and largerApplications include:S S Pastes S S Creams S S Gels S S Putty S S Mayonnaise S S MasticHELIPATH STANDHelical flow patternOriginall8586HELIPATH STAND DATAHELIPATH STAND DATA8687Screw-type spindle pumps fluid through annular gapOriginally designed to measure solder pasteShear rate range of 0.07 to 166 sec-1Viscosity range up to 9 x 106 cPS SLow range is a function of fluid pumpabilitySample sizes 100 ml and largerApplications include:S S Solder Pastes S S Screen Print Inks S S Pie Filling S S Gels S S CreamsSPIRAL ADAPTERScrew-type spindle pumps flui8788Wells-BrookfieldWells-BrookfieldCAPCAPSample size 2 mLSample size 1 mLShear rates from 0.2 sec-1 to 1,875 sec-1Shear rates from 165 sec-1 to 26,600 sec-1CONE/PLATEOriginally designed to measure bloodWells-BrookfieldCAPSample size8889CONE/PLATEWells-BrookfieldWells-BrookfieldCAPCAPCONE/PLATEWells-BrookfieldCAP8990Wells-BrookfieldWells-BrookfieldTemperature to 100CViscosity ranges from 0.17 cP(mPas)to 2.5 x 106 cP(mPas)Applications include:S Blood and plasmaS Biological fluidS SlurriesS DispersionsS Coating formulationsCAPCAPTemperature 5-200CViscosity ranges from 10 cP to 150,000 cPApplications include:S PaintsS CoatingsS InksS Resins and PolymersS AdhesivesCONE/PLATEWells-BrookfieldCAPCONE/PLATE9091Brookfields most sophisticated instrument is appropriate for materials where controlled stress measurements are required.Also provides controlled shear rate capability.R/S RHEOMETERBrookfields most sophisticate9192Originally designed for materials where both controlled stress and controlled rate measurements are required.Cone/PlateCone/PlateTemperature-20C-250CViscosity ranges from 100 cP-1.6 x 106 cP(mPas)Plate/PlatePlate/PlateTemperature-20C-250CViscosity ranges from 100cP-9.9 x 106 cP(mPas)R/S RHEOMETER Applications include:S SPetrochemicals S SCosmetics&DetergentsS SPolymers S SCoatings,Inks,PaintsS SFoods S SChemicals S SPharmaceuticalsOriginally designed for materi9293VANE SPINDLESMinimal disruption of sample during spindle immersionKeeps particles in suspension during testing cycleViscosity data includes complete flow curve analysisProvides information on yield behavior at low rotational speedsOriginally designed for paste-like materials,gels and fluids where suspended solids migrate away from the measurement surface of standard spindles.VANE SPINDLESOriginally design9394ROTATING PADDLEASTM METHOD D562ROTATING PADDLEASTM METHOD D59495VISCOSITY DATA ANALYSISVISCOSITY DATA ANALYSIS9596TEST DATATEST DATA9697MULTIPLE FLOW CURVE PLOTSMULTIPLE FLOW CURVE PLOTS9798SAMPLE VISCOSITY DATAFROM LABORATORY TESTSSAMPLE VISCOSITY DATAFROM LAB9899SAMPLE VISCOSITY DATA FROM LABORATORY TESTSSAMPLE VISCOSITY DATA FROM LAB99100流变学及方法论ppt课件100101SHEAR RATE RANGE&PRACTICAL APPLICATIONSSHEAR RATE RANGE&PRACTICAL A101102Estimate the velocity of the paint brush=50 cm/secEstimate the thickness of the layer of paint being applied=y=0.01 cmCalculate shear rate=50 cm/sec .01cm=5,000 sec-1Example:Shear rate of applying paint with a brush:vySHEAR RATE RANGE&PRACTICAL APPLICATIONSExample:vySHEAR RATE RANGE&102103For example:The paint industry sets targets for viscosity vs.shear rate to achieve optimum application performance.PRACTICAL APPLICATIONFor example:The paint indust103104Math models are used to convert viscosity data into a straight line plot on log-log axes.This simplified graph of viscosity data is useful in characterizing yield values and shear sensitivity of the test sample.MATHEMATICAL MODELSMath models are used to conver104105“g g”as the free variable in these equations denotes the shear rate.t t is,of course,the shear stress.Often other even more complicated equations have also been tried,but they are rarely used for practical applications.Any equation can only give an acceptable approximation of the real flow curve within certain shear rate ranges.Extrapolation beyond these limits can lead to very erroneous conclusions.TYPICAL MATH MODELS“g”as the free variable in th105106MATH MODELING EXAMPLESMATH MODELING EXAMPLES106107How to Improve QC MethodologyHow to Improve QC Methodology107108Good product quality can be related to rheological properties.Once the correlation has been established using flow curve evaluation,the desired product may be manufactured consistently within clearly defined QC limits.This will probably require running more than just a single paint viscosity test.APPLIED VISCOMETRY CAN ENHANCE PRODUCT QUALITYGood product quality can be re108109sensory feeling of creaminess and/or smoothnessSoupsyield stressviscosityswallowingsaggingPaints,Varnishes,CoatingsPolymerization ReactionsChocolate EnrobingEXAMPLES of INDUSTRIAL PRODUCTS AND THEIR QUALITY CHARACTERISTICS PRODUCTPRIMARY QUALITYCHARACTERISTICCHARACTERISTICRELATEDRHEOLOGICALPROPERTYretention of decorationyield stressviscositythixotropyyield stressviscositythixotropyend-point of reactionviscositybrushing,sprayinglevelingsensory feeling of creaminess 109110CURRENT TEST METHODCURRENT TEST METHOD110111IMPROVED TEST METHODIMPROVED TEST METHOD111112ADVANCED TEST METHODADVANCED TEST METHOD112113MORE ADVANCED TEST METHODMORE ADVANCED TEST METHOD113114REASONS FORON-LINE VISCOSITY MEASUREMENTREASONS FORON-LINE VISCOSITY 114115MANUAL VISCOSITY CONTROLQC LAB VISCOMETERMANUAL VISCOSITY CONTROLQC LA115116RELIABLE VISCOSITY CONTROLON-LINE VISCOMETERRELIABLE VISCOSITY CONTROLON-116117HOW TO GO ON-LINEHOW TO GO ON-LINE117118ON-LINE PROCESS vs.LABORATORY MEASUREMENTRequirement:Laboratory and on-line viscometers must both analyze samples under similar conditionsNote:Poor correlation between laboratory and on-line viscometers often results from taking samples at different points or time in the process.ON-LINE PROCESS vs.LABORATORY118119LOCATION OF A LABORATORY SAMPLING POINTLOCATION OF A LABORATORY SAMPL119120IDEAL PROCESS VISCOMETER REQUIREMENTSReadily installed on existing equipment.Easily and effectively cleaned.Durable,requiring minimum maintenance.Capable of measuring under controlled conditions of defined shear rate.IDEAL PROCESS VISCOMETER REQUI120121TYPES OF PROCESS VISCOMETERSTYPES OF PROCESS VISCOMETERS121122Versatile,direct mounting ins