Pg.1of14VacuumInfusion-TheEquipmentandProcessofResinInfusionIntroductionTheVacuumInfusionProcess(VIP)isatechniquethatusesvacuumpressuretodriveresinintoalaminate.Materialsarelaiddryintothemoldandthevacuumisappliedbeforeresinisintroduced.Onceacompletevacuumisachieved,resinisliterallysuckedintothelaminateviacarefullyplacedtubing.Thisprocessisaidedbyanassortmentofsuppliesandmaterials.Inatypicalhandlay-up,reinforcementsarelaidintoamoldandmanuallywetoutusingbrushes,rollers,orthroughothermeans.Animprovementonthatmethodistouseavacuumbagtosuckexcessresinoutofthelaminate.Vacuumbagginggreatlyimprovesthefiber-to-resinratio,andresultsinastrongerandlighterproduct.Ifyouareunfamiliarwithvacuumbagging,werecommendreadingourbrochure,VacuumBaggingEquipmentandTechniquesforRoom-TempApplications,asVIPrequiresexperienceinthisareaandusesmanyofthesameprinciples.Vacuuminfusionbuildsupontheseprinciples,providingfurtherimprovementstothelaminationprocess.BenefitsofVacuumInfusionVacuuminfusionprovidesanumberofimprovementsovertraditionallyvacuumbaggedparts.Thesebenefitsinclude:?Betterfiber-to-resinratio?Lesswastedresin?Veryconsistentresinusage?Unlimitedset-uptime?CleanerVIPoffersabetterfiber-to-resinratiothanvacuumbagging.Atypicalhandlay-upusuallyresultsinexcessof100%fabricweightbyresin.Resinaloneisverybrittle,soanyexcesswillactuallyweakenthepart.Vacuumbaggingcanreducethisnumbersignificantly;however,itisstillnotidealandcanleadtoadditionalproblems.Whilevacuumbaggingcertainlyimprovesonthehandlay-up,thereisstillahandlay-upinvolved.Becauseofthis,thelaminatewillalwaysbegininanoversaturatedstate.Vacuumpressurewillremovemuchoftheexcessresin,buttheamountremovedstilldependsonavarietyofvariablesincludingreinforcement,resin,timefactors,andothers.Vacuuminfusiontakesadifferentapproach,inthatavacuumisdrawnwhilethematerialsarestilldry.Fromthatpoint,resinisinfusedusingvacuumpressure.Ratherthanstartingwithexcessanddrawingresinout,VIPstartswithnoneandpushesresinin.Ideally,anyexcessresinthatisintroducedwilleventuallybesuckedoutintothevacuumline.Asaresult,onlytheminimumamountofresinisintroduced.Thislowersweight,increasesstrength,andmaximizesthepropertiesoffiberandresin.PartsconstructedusingVIPcanapproachprepreglevelsofresincontent.DuetothenatureofVIP,resinusagebecomesverypredictable.Whileastandardlay-upvariesinresincontentduetothehumanvariable,VIPisremarkablyconsistent.Evenwhencreatingalargeproduct,resinusagewillbepredictablysimilaruponrepeatedattempts.Thisresultsinlesswastedresin,andmoreimportantly,lesswastedmoney.Pg.2of14Vacuuminfusionprovidesanothervaluablebenefit:time.Afrequentproblemthatcanariseinvacuumbaggingisthetimefactor.Manyresinshaveapot-lifeofabout30minutes,thoughtherearecertainlysome(suchasourSystem2000Epoxy)thatofferworktimesofupto2hours.Evenso,thattimelimitisextremelycriticalinvacuumbaggingapplications.Largeprojectscaneasilyapproachthe2hourmark,andevensmall,seeminglysimpleprojectscanquicklyturnfranticwhenapeskyleakinthevacuumsealcannotbefound.Also,dependingonwhenthebagisapplied,theamountofresinremovedcanvaryfromparttopart.Vacuuminfusion,however,offersunlimitedset-uptime.Becausethevacuumisappliedwhilereinforcementsarestilldry,thereisnoresinclocktoworkagainst.Afterthebagisapplied,leakscanbepatientlysoughtout.Ifsomethingisnotsittingproperly,simplyreleasevacuumandreadjust.Notimeconstraintsareintroduceduntilitisdecidedthatitistimetoinfusetheresin.Untilthatmoment,changescanbemadeagainandagain.Finally,vacuuminfusionisamuchcleanerprocess.Therearenobrushesorrollers,andthereforenosplashingorspattering.Noonewillberequiredtohoveroveranopenmold,saturatingalaminatebyhand,tryingnottodriponhimself.Inaddition,therearelessresinfumestocontendwith.Becausetheonlyfumesradiatefromtheresinreservoir,theyaresomewhatcontainable.VIPprovidesacleaner,safer,andfriendlierworkenvironment,thoughitisstillimportanttoworkinawellventilatedareaandweararespiratorandotherappropriatesafetyequipment.PotentialPitfallsLikeanylaminatingprocess,VIPisnotwithoutitsdrawbacks.Whenattemptinginfusionforthefirsttime,itisimportanttokeepthefollowingideasinmind.Complicatedset-upEasytoruinapartTrialanderrorThoughset-upistime-limitfree,itissomewhatmorecomplicated.Vacuumbaggingrequirestheplacementofonlythevacuumtubing.Vacuuminfusionrequiresnotonlyvacuumtubesbutresininletsaswell,nottomentionin-bagextensionsofthesetubes.Placementofthesevacuumandresinlinesvariesfromparttopart,andthereisnoonewaytosetthemup.Theseconsiderationsmustbeevaluatedpriortolay-up,orelsethepartcouldberuined.Thisleadsintothenextpitfall;itisveryeasytodestroyapart.Typically,onceinfusionbegins,thereislittlethatcanbedonetocorrectanyerrors.Forexample,ifaleakweretooccur,eventhesmallestamountofairintroducedcouldbepotentiallyfataltoapart.Itwouldprobablyresultinresinpooling,undersaturation,orevenacompletestoppageofresinflow.Thoughtherearecertainlysomecaseswhereproblemscanbecorrected,itshouldnotbeexpected.Thebestprotectionfromdisasteriscarefulplanning.Duetothecomplexityandeaseoferror,VIPshouldbeviewedasatrial-and-errorprocess.Thebestmindsettoha