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7ReasonstoReconsiderUltrasonicSealingforYourVFFSBaggingLineBillAurand,Sonics&Materials,Inc.
Inrecentyears,manycompanieshavebeguntoconsiderconvertingtheirVFFSbaggingmachinesfromheatsealingtoultrasonicsealingtechnology.Theideaofreducingfilmconsumptionbynarrowingthesealwidthisacommondrivertowardultrasonicsealing.Anotheristheunderstandingthatanoccasionallettuceleaforpieceofcheesethatgetscaughtinthesealareawillnolongerpresentaproblembecausetheultrasonicsystemwillsealrightthroughtheproduct.Whilethesearegoodreasonstoconsiderultrasonicsealing,amorethoroughevaluationrevealsevengreaterbenefits.Belowisalistofadvantagesthatshouldbeinvestigatedwhenconsideringtheswitchtoultrasonicsealingtechnology.1-ReducedfilmcostWithultrasonics,thesealthicknessistypicallyreducedto2mmorless.Inonelarge-scalestudy,crosssealthicknessreductionresultedinan11%filmsavingsaccordingtoalargeCPGinthesnackfoodmarket.Seeillustrationbelow(©EWI.Imageusedwithpermission)
• Inadditiontonarrowingtheseal,ultrasonictechnologycanprovideadditionalfilmsavingsby
allowingthesamevolumeofproducttobecontainedinasmallerpackage.Thesmallerbagismadepossiblebecauseheadspacecanbereducedwithoutconcernforproductinthesealarea.Theoverallbagsizecanpotentiallybereducedbyasmuchas20%,dependingupontheproductbeingpackaged.Insomecases,zeroheadspacepackagingispossible.
• Simpler,lesscostlyfilmstructurescanbeconsidered.Ultrasonicsealingcanbeusedwithoutasealantlayerinsomecases.Todate,evaluationofultrasonictechnologyhasprimarilybeendoneonfilmsdesignedforheatsealing.Whenfilmsuppliersbegindevelopingproductsspecificallyforultrasonictechnology,evengreatersavingswillberealized.
2-Lesswastedproduct
• Theabilitytosealthroughcontaminationmeanswasteisnolongergeneratedwheninternalproducthangsupinthesealarea.Notonlydoesthisenhancetheprocessatthebagger,itfurtherreduceswastedownstream.Faultysealscreatedwithheatsealingmaynotbediscovereduntiltheyhavedamageddozensofotherpackagesduringshipment.
• Feweroverallrejectsmeansmoreproductoutthedoor.Itisnotuncommonforultrasonicsealingtoseerejectratesaslowas1:100,000seals.Ofcoursethisvarieswithfilmtypeandproductbeingpackaged,butoncetheultrasonicprocessisoptimized,thereisnobetterwaytoguaranteehighqualityhermeticseals.
3-Enhancedthroughput
Ratherthansimplycomparingheatsealtimesversusultrasonicsealtimes,CPGsshouldconsidertotalproductivity.Sealtimealonedoesnotdictateoutput.Actualultrasonicsealtimesareusuallyverysimilartoheatsealingtimes.Theincreaseinproductivityisduetootherreasons.Alsofactorinthefollowing:• Higherthroughputduetoreducedconcernsoverproductinthesealarea.Becauseultrasonic
toolscansealthroughproductcontamination,lesstimeisrequiredtowaitforproducttofallclearofthesealjaws.Thereforethemachinecansafelybesettorunatafasterrate.
• Increasedmachinespeedsduetotheeliminationofhottackconcerns.Whenbaggingheavierproducts,residualheatinthesealscancausepackagefailuresunlessthemachineissloweddowntoallowthesealstocool.Ultrasonicsealingdoesnothavehottackissuesbecausethetoolsremaincoolandlessoverallheathasbeenappliedtothefilm.Ultrasonicsealsexhibitfullstrengthalmostimmediately.Seeillustrationbelow.
• Productivityisfurtherincreasedwithultrasonictechnologybecausetheprocessdoesnot
requireanywarmuptime.ThefirstbagofthedayfromanultrasonicVFFSsystemisperfect.Typicalheatsealjawscanrequireupto15minutesofwarmuptime.15minutes@80bagsperminute=1200additionalbagsproducedusingultrasonicseachtimethemachineisstartedup.
4-Improvedproductquality.
Whilethisshouldbeaprimarydriver,strangelytheproductqualityenhancementsarerarelyfullyevaluatedbyCPGs.Considerthefollowing:
• Ultrasonicsealsonaverageare‘tighter’andmorehermeticthanheatseals.Asaresultofbettersealquality,thereductioninOxygentransmissionratewithultrasonicsealingisdramatic.Nitrogen
Heatsealing Ultrasonicsealing
flushismaintainedformanymonthsversusafewweekswithheatsealing.Thisresultsinfresherproductswithmuchlongershelflife.Seeillustrationbelow(©EWI.Imageusedwithpermission)
• Further,whenultrasonictechnologyisusedonVFFSbaggers,hermeticsealsarecreatedevenwhenthefilmiscreased,makingtheentireprocessmuchmoreforgivingandproductive.
5-Enhancedsafetyandmaintenance
• BasedonanextendedstudydoneatalargeCPGfacility,maintenancepersonnelwerestronglyinfavorofultrasonicsealingoverheatbecausetherearenoissueswithburnswhenworkingwithultrasonicsystems.Oncepowereddown,itiscompletelysafetohandletheultrasonictools.
• Inaddition,heatsealingtoolscanbetimeconsumingtocleanduetotheinternalproductandfilmbecomingbakedonovertime.Becauseultrasonictoolsstaycool,theyaremucheasiertoclean.
6-Reducedenergyconsumption
• Heatsealingdrawssignificantelectricalcurrentduringtheentireshifttomaintainthesetsealtemperaturewithinthejaws.UltrasonictechnologyisanOn/Offprocess,meaningthesystemdrawsessentiallynoelectricityexceptduringtheactualprogrammedsealtime.Withsealtimesasfastas100milliseconds,itiseasytoseehowultrasonictechnologycanprovideenergysavings.
7–Ultrasonicsealingisan‘intelligent’process
• Intoday’smanufacturingworld,blindprocessescannolongerbetolerated.Withheatsealingtechnology,operatorshavenowayofknowingwhetheranyspecificbagwassealedproperlyorevenunderthesameconditionsasthenext.Ultrasonicsealingprovidesintelligencetotheprocessbyallowingparameterssuchassealtime,peakpowerdrawandtheactualenergydeliveredintoeachcrosssealtobemonitored.Thisdatacanthenbeusedtotracktheprocessorevendivertsuspectbagsfortesting.
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Wehopethelistabovewillgiveyouabetterunderstandingofwhatultrasonicsealingtechnologycanbringtoyourpackagingoperation.Clearly,ultrasonicscanofferfarmoretothebaggingprocessthanmerelynarrowingthesealthicknessorcuttingthroughanoccasionallettuceleaf.Unfortunately,manyoftheotherbenefitscanbedifficulttoquantifyuntiltheprocesshasbeeninuseforaperiodoftime.Withoutfullknowledgeofalloftheadvantagesofferedbyultrasonicsealing,manyCPGsmaketheirdecisionbasedononlythetangiblematerial.Thisfact,combinedwiththehistoricallyhighcostandcomplexityofintegratingultrasonicsexplainswhyultrasonicsealingisn’tcurrentlybeingusedbyeveryone.Thegoodnewsisthatimprovementsinultrasonicequipmenttechnologyaswellasrecentadvancesinapplicationsprovideevenmorereasonstoreinvestigatethisbeneficialprocess.
• Thecostofultrasonicequipmentisnotashighasyoumayhavebeenleadtobelieve.Completecomponentsystemscannowbedeliveredatafractionofthecostofwhatwastypicaljustafewyearsago.Infact,eventurnkeyultrasonicconversionsforusedbaggingequipmentarenowacosteffectiveoption.
• Beyondbeingmoreaffordable,itshouldbenotedthatthecomplexityofcurrentultrasonicsealingsystemsisnotwhatitwasinthepast.Today’smodernsingleconverterdriveultrasonicsystemsarefarsimpler,moreuserfriendlyandmorerobustthanoutdated‘twinstack’designs.
• Inaddition,recentbreakthroughsinsealbeadgeometrynowenableultrasonicsealingtobeusedingussetapplications.Strong,hermeticultrasonicsealsacrossthetransitionfrom4layersoffilmto2layersarenowpossible.ThisopensupthepossibilityforultrasonicstobeappliedinapplicationssuchasgussetbagcrosssealsandsidesealsforstanduppouchesproducedonVFFSmachinery.
Withsomuchtobegainedbyusingultrasonicsealing,andthetechnologicaladvancementsintoday’smodernultrasonicpackagingsystems,therearecompellingreasonstogiveultrasonicsealingasecond(andcloser)look.AbouttheauthorBillAurandisthePackagingTechnologyManagerforSonics&Materials,Inc.Hebeganhiscareerinultrasonicsin1985asanUltrasonicWeldingApplicationsEngineerimmediatelyfollowinghiscollegeeducation.SincethenBillhasheldvariousmanagementlevelpositionswithinseveralAmericanandEuropeanultrasonicequipmentmanufacturers.Throughouthiscareer,Mr.Aurandhasbeenresponsibleforprovidingeducationalseminarsonultrasonictechnologybothdomesticallyandinternationallyforinternalemployees,customers,UniversitystudentsandlocalSPEandSPIchapters.Bill’smarketemphasisshiftedfromrigidplasticpartassemblytoflexiblepackagingin2010asnewinnovationsinultrasonictechnologyallowedittobesuccessfullyappliedinapplicationsthathadpreviouslybeenavoided.In2013,BillwasaguestspeakeronRecentAdvancementsinUltrasonicFilmSealingattheANTECconventioninCincinnati,OH.BillwasalsoaguestpresenteronUnderstandingUltrasonicFilmSealing,ItsBenefitsandLimitationsattheGlobalPouchForumWest,2014.
Sonics & Materials, Inc., 53 Church Hill Road, Newtown, CT 06470, USA Phone: (203) 270-4600, Fax: (203) 270-4610, Toll Free in USA: (800) 745-1105
Email: [email protected] Web: www.sonics.com
Sonics and Sonics & Materials are registered in U.S. Patent and Trademark Office.