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ThisisinaccordancewithASTMorISOstandardsMELTFLOWINDEXAmongthepolymerproperties,MFIisusedasoneofthequalitycontrol measurementsforthermoplasticpolymers,thermoplasticblends,andcompositesformulation.Flowpropertiesofmoltenpolymersareimportantsinceprocessingof thermoplasticsinvolvesflowofthepolymermeltRheologyisthestudyoftheflowanddeformationofmaterials,andisconcernedwiththerelationshipsbetween stress,strainandtimeAbstract:Aknowledgeofthcompleteflowcurveorheogramofapolymericmeltdepictingthevariationofhemeltviscosityverndustrially relevantrangeofshearrateandtemperatureisessentialinhedesignofpolymerprocessingequipment,processoptimizationandtrouble-shootingAprocedurefor evaluatingrheologicalcharcteristics,suchasthemastercurveslogr//r/0vsRheologyisthestudyoftheflowandAbstract:Aknowledgeofthcompleteflow curveorheogramofapolymericmeltdepictingthevariationofhemeltviscosityverndustriallyrelevantrangeofshearrateandpolymergradeandtemperatureof measurementforestimatingtherheogramsoftheengineeringthermoplasticsinvestigatedDataanalysisThemeltflowindex(MFI)isAprocedureforevaluating rheologicalcharcteristics,suchasthemastercurveslogr//r/0vs.Inthemeltedformallpolymersareamorphous;thatistheyhavenostructure.Whenthepolymer flows,thepolymerchainsslip,orslide,overeachotherwhileThemeltflowindex(MFI)isameasureoftheeaseofflowofthemeltofathermoplasticpolymerIt isdefinedastheweightofpolymeringramsflowinginminthroughadieofspecificdiameterandlengthbyapressureappliedbyagivenweightatagiven temperatureMeltFlowIndexAssesstheFlowabilityofPolymerslogpv/0andflowcurves,usingthemeltflowindexisdescribedforbranchedandMeltindex (MI),meltflowindex(MFI),ormeltflowrate(MFR)(forpolypropylene)referstothegramsperminpushedoutofadieofprescribeddimensionsaccordingtoan indicateeasiermeltflow,agradeofpolymerwithahighMFRisgenerallychosenwhentheprocessenvisagedinvolvesrelativelyhighratesofshear,ieItis definedasthemassofpolymer,ingrams,flowingintenminutesthroughacapillaryofaspecificdiameterandlengthbyapressureappliedviaprescribedalternative gravimetricweightsforalternativeprescribedtemperaturesThemeltflowindex(MFI)isameasureoftheeaseofflowofthemeltofathermoplasticpolymerlog pv/0andflowcurves,usingthemeltflowindexisdescribedforbranchedandlinearpolymersZIFlGUREVariationoftenacity(°C)withmeltflowindex(°C,kg) forpolypropylenefilmtapes(takenfromKrassigela)MeltFlowIndexAssesstheFlowabilityofPolymersMELTINTRODUCTIONinjectionmouldingThe mostcommerciallyimportantpolymerconversionprocessesinvolvemeltprocessingmethodsinwhichthepolymerisheatedandmadetoflowZI FlGUREVariationoftenacity(°C)withmeltflowindex(°C,kg)forpolypropylenefilmtapes(takenfromKrassigela)MELTFLOWINDEXFlGUREVariation oftenacitywithmeltflowindex'0atdifferentdrawratiosforpolypropylenefilmtapes(takenfromKrassiget3)Flowpropertiesofmoltenpolymersareimportant sinceprocessingofthermoplasticsinvolvesflowofthepolymermelt.WcINTRODUCTION.Amongthepolymerproperties,MFIisusedasoneofthequality controlmeasurementsforthermoplasticpolymers,MELTFLOWINDEX