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ID:57383684
大小:860.50 KB
页数:21页
时间:2020-08-14
《Natural-Latex天然胶乳-胶乳英文ppt-橡胶课件.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、NaturalLatexControlandIndustrialProceduresEmilyLiuMaterialScienceNaturalLatexA.IntroductionB.ControlProceduresIntroductionCentrifugedlatexisprocessedintofinalarticlesbydipping,extruding,andcoating.Differentarticleshavedifferentphysicalandchemicalrequirements,whichmeansthatthelatexusedintheirmanufac
2、turemustbemodifiedbytheadditionofagreatvarietyofsubstancesthatgiveeach"formulation"itsuniquecharacteristics.Thesecharacteristicsarewell-specifiedandmustbecarefullycontrolled.ExampleofaControlSheetforLATZLatexAnexampleofacontrolsheetforthetypeofnaturalrubberlatexthatiscommonlyusedinmakingsurgicalglo
3、vesisgivenintheTable1.ThepurposeofthisPPT:Weexplainbrieflyhowsomeofthesecharacteristicsarecontrolled.ControlProcedures3456DryRubberContent(DRC)SurfaceTensionpHMeasurementMechanicalStabilityKOHNumberTotalSolidContent(TSC)Viscosity271ControlProcedures1.DeterminationoftheTotalSolidContent(TSC)ofLatexA
4、ddyourtitleinhereTheTSCoflatexisobtainedbydryingasampleoftheliquidlatextobeassayedandweighingtheresidue.Thevalueobtainedisthesumofthedryrubbercontentplusthesolidnonrubbercontents,whichincludestheprotein.Latexthatisusedintheproductionofgloves,catheters,andsoonhasaTSCof60~62%.TheDRCoflatexisobtainedb
5、ycoagulatingtherubberinthesampleoflatextobeassayedwithaceticacid,thendrying,washingandweighingtheresultingmassofrubber.ThedifferencebetweentheTRCandtheDRCisameasureoftheofnaturallatex.ThedifferencebetweentheTRCandtheDRCisameasureofthetotalnonrubbercontentsofthelatex.Theselatterconstituentsareprinci
6、pallylatexproteins,lipids,andmineralsalts.InthecaseofHAandLATZlatexes,thosearecommonlyusedintheproductionofgloves,thenonrubberconstituentsmakeupbetween1%and2%ofnaturallatex.2.DeterminationoftheDryRubberContent(DRC)ofLatex3.MeasurementofSurfaceTensionDeterminationofthesurfacetensionoflatexisaveryuse
7、fulmeasure,assurfacetensionisafunctionof:1.Theamountofsoapaddedtostabilizethelatex;2.Thenaturalsoapsformedafterconcentrationfromfattyacidsinthelipidphaseofthelatex;3.Themineralsalts(mg/Na)thatarepresentinth
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