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GuidePaperboard
Paperboard Guide
Contents 2
Introduction 3
1. Information about Stora Enso and Consumer Boards 4
1.1 StoraEnsoinbrief 5 1.2 StoraEnsoConsumerBoards 6 1.3 Sustainabilityinpackaging 7
2. Paperboard making and paperboard grades 8
2.1 Paperboardmaking 9 2.2 Paperboardgrades 11
3. Barrier coating 15
4. Paperboard handling recommendations 18
5. Printing methods 19
5.1 Offsetprinting 21 5.2 Gravureprinting 22 5.3 Flexoprinting 23 5.4 Inks 24 5.5 Digitalprinting 25 5.6 Practicalprintinginstructions 26
6. Converting and Finishing 28
6.1 Varnishing 29 6.2 Embossing 31 6.3 Hot-foilstamping 31 6.4 Die-cuttingandcreasing 32 6.5 Glueing 34 6.6 Lamination 35
7. End uses 36
7.1 Graphical 39 7.2 Beverageandmultipack 40 7.3 Chocolateandconfectionery 41 7.4 Cigarette 42 7.5 Cosmeticsandluxury 43 7.6 Detergentsandhousehold 44 7.7 Food 45 7.8 Pharmaceutical 46 7.9 FoodService 47 7.10 Liquid 47
8. Stora Enso Consumer Boards production and service facilities 48
8.1 Paperboardmills 49 8.2 Extrusioncoatingplants 51 8.3 Partnerservices 52
9. Testing methods 53
10. Glossary 57
Contents
3 Paperboard Guide
Creatinginnovativepackagesandbril-
liantgraphicalproductsfromadvanced
paperboardmaterialsisbothascience
andanart.Asaruleofthumb,thesky
isthelimitastotheimplementationof
artisticdesignsordemandingprint-
ingandfinishingeffects.However,the
moreweknowaboutthebehaviourof
paperboardinvariousrefiningprocesses
andindividualenduseenvironments,
thebettertheresult.
ThisPaperboardGuidehasbeen
compiledtothatveryend–toserve
ourpartnersandtheircustomerswith
accurateinformationthathelpsmake
excellenceoutoftheordinary.
Asischaracteristicofeducational
material,alotofthesubjectmatter
dealswithconcepts,definitions,ab-
breviationsandprinciples.Inaddition
toexplainingthebasicvocabulary,the
Guidepresentsanoverallpictureofthe
paper-boardworldandclarifiessomeof
thekeyissuesrelatedtoit.
Introduction
Welcome to the enchanting world of paperboard.
PasiAhokasVP,GraphicalBoards
<< Contents
Information
andConsumerBoards
aboutStoraEnso
Stora Enso Consumer Boards 4<< Contents
StoraEnso’ssalestotalledEUR13.2billionin2005.TheGrouphassome46000employeesinmorethan40countriesonfivecontinents.StoraEnsohasanannualproductioncapacityof16.9milliontonnesofpaperandboardand7.7millioncubicmetresofsawnwoodproducts,including3.3millioncubicmetresofvalue-addedproducts.StoraEnso’ssharesarelistedinHelsinki,Stockholm,andNewYork.
StoraEnsoservesitsmainlybusiness-to-businesscustom-ersthroughitsownglobalsalesandmarketingnetwork.Aglobalpresenceprovideslocalcustomerservice.Customersincludepublishers,printinghouses,andmer-chants,aswellasthepackaging,joinery,andconstruc-tionindustries–andaremainlyconcentratedinEurope,NorthAmerica,andAsia.AsStoraEnsomovesintothefuture,theGroupisfocusingonexpandingitsopera-tionsinnewgrowthmarketsinChina,SouthAmerica,andRussia. TheGrouphasproductionfacilitiesinEurope,NorthandSouthAmerica,andAsia.Modernproduc-tioncapacity,combinedwithefficientrawmaterialandenergysourcingandefficientprocesses,ensureexcellentcontinuityofproduction.
StoraEnsoiscommittedtosustainability–economic,environmental,andsocialresponsibilityunderpinsourthinkingandourapproachtoeveryaspectofdoingbusi-ness.TheGroupbuildsaccountabilityintoitsoperationsbybeingtransparentandengaginginopendialoguewithitsstakeholders.Group-widetargetsandcleargovernanceareusedtomonitorandmeasurehowwellStoraEnsoperformsintermsofsustainability.
1.1 Stora Enso in brief
Information
andConsumerBoards
aboutStoraEnso
StoraEnsoisanintegratedpaper,
packaging,andforestproductscompany,
producingpublicationandfinepaper,
packagingboard,andwoodproducts
–allareasinwhichtheGroupisaglobal
marketleader.
5 Stora Enso in Brief
committed to
sustainability
<< Contents
1.2 Stora Enso Consumer Boards– providing packaging solutions worldwide
Fibre-basedmaterialsenjoyastrongandwell-deservedstatusinthepackagingworld.Paperboardissmoothandstrong,lightandbright,versatileandcost-effective.Agenerousprintingsurfaceandsuperbprintqualitymakespaperboardcartonsidealinformationcarriersandbrandbuilders.Reliabilityinhigh-speedfillinglinessavesmoneyandminimizesproductiondowntime.Renew-ablefibresalsomakeaparticularlywell-foundedchoiceenvironmentally.
Theultimatechallenge,however,liesinusingthefullpotentialofthematerialintelligentlyandinnovativelytocreatesolutionsandconceptsthatwillhaveacom-petitiveedge–inproductprotection,materialsavings,productionandlogisticscosts,tradepreference,con-
sumeracceptance,shelfpresenceorrecyclingefficiency.Suchsolutionsdonotmaterializeoutofthinair.Theystemfromactiveinteractionwiththewholepackagingcommunity.AndthatiswheretheofferingofStoraEnsoConsumerBoardsreallycomesintoitsown.Weproduceawideselectionofpaperboardsineverycategoryandprovidethelargestvarietyofpolymercoat-ings.Wehavestrongandmodernpulpandboardmillsthat,togetherwithoursalesstaffandServiceCentrefa-cilities,ensureconsistentquality,fastserviceandreliabledeliveries.Butevenmorethanthat,wearecommittedtoverticalinnovationinthewaywecooperatewithourpartnersacrosstheboardtopromotetheefficiencyandsustainabilityoffibre-basedpackaging.
Information
andConsumerBoards
aboutStoraEnso
Liquid FreshLiquid Ambient
Stora Enso Consumer Boards 6
Stora Enso Consumer Boards
<< Contents
Information
and Consumer Boards
about Stora Enso
1.3 Sustainability in packaging
Sustainable development in packaging means solutions that satisfy present needs in an optimal way without compromising the ability of future generations to meet their own needs. Fibre-based boards provide a powerful means of achieving those goals throughout the pack-age’s life-cycle. Here are some of the basic issues:
Wood, a renewable and recyclable resource, is the main raw material in our packaging boards. We apply the prin-ciples of environmental and social responsibility for wood procurement and sustainable forest management.
Paperboard is produced at an integrated mill, using mainly renewable energy derived from the wood in the pulping process.
Versatile and light paperboard packages prevent product loss by effectively protecting packed materials against
physical damage, contamination and light. Product in-formation can be printed directly onto the surface of the paperboard, so no extra labels are needed.
Space-saving designs are particularly economical in transportation. Efficient logistics reduce fuel consump-tion and emissions to the atmosphere.
Paperboard packaging is a valuable resource in itself, with many potential uses. Packaging boards are made from fibres with good strength properties and can be recycled for a number of paper and paperboard grades. In the case of polymer-coated boards, the plastic fraction can be used for energy production, replacing fossil fuels, or can be recycled when appropriate.
For a more detailed presentation of sustainability in pack-aging, view the multimedia.
7 Sustainability in Packaging << Contents
Paperboard
paperboardgrades
makingand
Paperboard making and paperboard grades 8<< Contents
Paperboard
paperboardgrades
makingand
2.1 Paperboard Making
Thebasicprinciplesofpaperandpaperboardmakinghavenotchangedformorethantwothousandyears.Fibresgainedfromtimberareevenlydistributedinwater.Multiplelayersoffurnishareapplied,oneaftertheother,onawire.Thewaterisdrainedfromthepulpand
thelayersareformedintoastrongfibremat.Asmoothsurfaceisachievedbycoatingandcalendering.TheexcellentqualityofStoraEnsopaperboardsistheresultofadvancedtechnologyandtheuseofhigh-qualityrawmaterials.
Raw Materials used for Paperboard Production
Chemical PulpWoodchipsarecookedwithappropri-atechemicalsinanaqueoussolutionathightemperatureandpressure.Theobjectiveistodissolvetheligninandseparatethefibresintact.Thepulpcanbeusedunbleachedorbleachedtothebrightnessneeded.
HardwoodPulpmadeofdeciduousbroad-leavedtreessuchasbirch,oak,beech,aspenoreucalyptus.Characteristicaretheshortfibres.
SoftwoodPulpproducedofpine,spruce,orotherconifers.Thefibresarelong.
Watermeansoftrans-portandsolvent.
PigmentsNaturalcoatingpigmentsandfillers.GroundCalsiumCarbonate(GCC)andKaolinClay.
LatexWaterdispersionoforganicbinderforthecoatingpigment.
Components Coating Colourrheologymodifiers
Sizing Agentssuchasnaturalresinorsyntheticsizesareaddedtoincreasestrengthanddecreaseabsorbance.
Wet-end Additivesand Retention Aide.g.starchandaluminiumsulphate.
Secondary fibresaregainedfromsortedrecoveredpaperorboardbypurifyingandsometimesdeinkingandbleaching.
CTMP (Chemi Thermo Mechanical Pulp)Woodchipsareimpregnatedwithappropriatechemicalsandheatedbeforeseparatingthefibresbyamechanicalrefiningprocess.Thepulpisbleachedandwashedinseveralsteps.
GroundwoodLogsofdebarkedsoftwoodarepressedagainstarotatinggrindingstonewhilewaterisaddedinordertoseparatethefibres.
Mechanical Pulp
9 Paperboard making and paperboard grades << Contents
Paperboard
paperboardgrades
makingand
Paperboard ProductionThepicturebelowillustratesonetypicalexampleofpaperboardmachinelay-out.
Wire Section Press Section Pre-Drying Section
Wire Section:Thewebisformedinthewiresectionbypumpingamixtureofwaterandpulpfromtheheadboxesontothewire.Thewatercontentisover99%,whichiswhythispartofapaperboardmachineisalsoknownasthewetend.Thewaterisdrainedoffandthefibresbondtogether.Theindividuallayersoffibrearecouched.Anevenfibreformationisvitaltoensureoptimumstrength,surfacesmoothnessanduniformity.Afterthewiresectionwatercontentis80%.
Press Section:Inthepresssection,waterisremovedfromthewetwebbymechanicalcompressioninthenipsformedbytworolls.Theremovedwaterisreceivedbyafelt.Afterpresssectionwatercontentisapproximately60%.
Pre-Drying Section:Thepaperboardwebisfurtherdriedbyaseriesofsteam-heateddryingcylinders.
Pre-Drying Section
Glazing Cylinder
Post-Drying Section 1 Coating Section
Post-Drying Section 2Shoe Calender
Glazing Cylinder:ThetopsideofthewebcanbesmoothedbycontactwithaYankeecylinderhavingahighlypolishedsurfaceorwithsocalledshoecalender.Noteverypaperboardmachinehastheseoptions.
Post-Drying Section 1 and 2:Additionalreductionofmoisturecontent.
Coating Section:Dependingonthequalityrequired,thewebcanbecoatedwithone,twoorthreecoatingstationsperside.
Reeler Section Winding Paperboard Reel
Gloss Calender
Calendering: Thesmoothingcalenderfurtherregulatesthesurfacequality.Dependingonthegrade,thesurfaceisadditionallycalend-eredwiththehotsurfaceoftheglosscalender.
Winding:Thefinishedpaperboardiswounduptoajumboreelwhichisthenrewoundintonarrowerreelsandaccordingtocustomerrequirements,eithersenttocustomersinreelsorcutintosheets.
Paperboard making and paperboard grades 10
Extrusion coatingForsomeend-usespaperboardcanbeextrusioncoated.Extrusioncoatingisaseparateprocessafterthepaper-boardproduction.Formoreinformationonthebarriercoatingoptionsseechapter3.0.
<< Contents
Paperboard
paperboardgrades
makingand
2.2 Paperboard Grades
Agreatvarietyofgradesarecommerciallyavailableandthetermsusedtodescribethemvaryfrommarkettomarket.Belowthegradecategoriesarebasedonfibregradesandproductiontechnology.Eachgrademaybetailoredformanyendusesandforindividualcustomerneeds.
Paperandpaperboardaremadewiththesamebasetechnology.Paperprovidesmainlytheprintingsurface,paperboardbothprintingsurface,stiffness,strengthandotherpropertiesnecessaryinpackagingandgraphicenduses.Usuallybasisweight,caliperandstiffnessarehigherthanthoseofpaperandalsomostofthepaperboardgradesaremultiplyproducts.
FBB (Folding Boxboard)
Alayerorlayersmadeofmechanicalpulpisbetweenlayersofchemicalpulp.Mechanicalpulpmaybestone-groundwood(GW),pressurizedgroundwood(PGW),thermomechanicalpulp(TMP)orchemi-ther-momechanicalpulp(CTMP).Thetoplayerisbleachedchemicalpulpandthereverselayercanbebleachedorunbleachedchemicalpulp.Thetopandreversesidemaybecoatedwithmineralorsyntheticpigments.
SBS (Solid Bleached Sulphate)
Paperboardentirelymadeofbleachedchemicalpulp.Thetopsideandreversemaybecoatedwithmineralorsyntheticpigments.
SUB (Solid Unbleached Board) / SUS (Solid Unbleached
Sulphate)
Paperboardmademainlyofunbleachedchemicalpulp.Toachieveawhitesurface,itmaybecoatedwithminer-alorsyntheticpigments,sometimesincombinationwithalayerofbleachedfibresunderthislayer.SomeCTMPorrecycledfibresmaypartlyreplacetheunbleachedsulphatepulp.
Double/triplecoating
Bleachedchemicalpulp
Bleachedmechanicalpulp
Bleachedchemicalpulp
(Coating)
Double/triplecoating
Bleachedchemicalpulp
Bleachedchemicalpulp
Bleachedchemicalpulp
Single/doublecoating
Double/triplecoating
Bleachedorunbleachedchemicalpulp
Unbleachedchemicalpulp(mixedwithCTMP/recycledfibres)
Unbleachedchemicalpulp(mixedwithCTMP/recycledfibres)
(Coating)
11 Paperboard making and paperboard grades << Contents
Paperboard
paperboardgrades
makingand
Paperboard making and paperboard grades 12
WLC (White Lined Chipboard)
Multi-layerpaperboardcomprisingatleastonemid-dlelayerofmainlyrecoveredfibres.Thetoplayerisbleachedvirginchemicalpulporwhiterecoveredpulps.Betweenthetoplayerandthemiddlelayer(s)therecanbealayerofchemical,mechanicalordeinkedrecycledfibres.Thereverselayercanbemadefromselectedrecy-cledfibresorbleachedand/orunbleachedvirginfibres.Thetopandreversesidemaybecoatedwithmineralorsyntheticpigments.
LPB (Liquid Packaging Board)
LiquidPackagingBoards(LPB)areusedforthepackag-ingofliquidfoods,suchasmilkorjuice.ThebaseboardmaybeeithercoatedoruncoatedFBB,SBSorSUB.Thepaperboardisplasticcoated–oftenwithPE(Poly-ethylene),high-barrier-orfoil-laminatedforlong-lifebeverages.
Two-sidedPEcoating
PECoating
Board
PECoating
PEcoating
Board
Barrierlayer
PEcoating
Double/triplecoating
Bleachedchemicalpulp/whiterecoveredpulps
Recoveredpaperorpaperboardbrown/grey
Bleachedchemicalpulp/
anyofthepulpsabove
(Coating)
<< Contents
13 Paperboard making and paperboard grades
Definition (DIN 19303) Type Description Pulp Stock
uncoated coated
AZ SBS Cast-coatedsolidbleachedboardwithwhiteback Fullybleachedchemicalpulp
AC1 FBB Cast-coatedfoldingboxboardwithwhiteback Chemicalandmechanicalpulp
AC2 FBB Cast-coatedfoldingboxboardwithcreamback Chemicalandmechanicalpulp
UZ GZ SBS Solidbleachedboard Fullybleachedchemicalpulp
GN1 SUS/SUB/CNK Solidunbleachedboardwithwhiteback Unbleachedchemicalpulp
GN4 SUS Solidunbleachedboardwithbrownback Unbleachedchemicalpulp
UC1 GC1 FBB FoldingBoxboardwithwhiteback Chemicalandmechanicalpulp
UC2 GC2 FBB FoldingBoxboardwithcreamback Chemicalandmechanicalpulp
UT1 GT1 WLC Whitelinedchipboardwithwhiteback Secondaryfibres
UT2 GT2 WLC Whitelinedchipboardwithcreamback Secondaryfibres
UT4 GT4 WLC Whitelinedchipboardwithbrownback Secondaryfibres
UD1 GD1 WLC Whitelinedchipboardhighbulk≥1,45cm3/g Secondaryfibres
UD2 GD2 WLC Whitelinedchipboardhighbulk<1,45cm3/g,>1,3cm3/g Secondaryfibres
UD3 GD3 WLC Whitelinedchipboardhighbulk≤1,3cm3/g Secondaryfibres
Overview of Paperboard Nomenclature
AccordingtoDIN19303,anypaperboardcanbedescribedbyacombinedcodeoftwolettersortwolettersandonefigure.
The first letter describes the type of surface treatment:
A=cast-coated G=pigment-coated U=uncoated
The second letter stands for the main furnish:
Z=bleachedchemicalpulp N=unbleachedchemicalpulp C=mechanicalpulp T= secondary-fibrepulpwithwhite, creamorbrownreverse D=secondary-fibrepulpwithgreyreverse
Except for the D grades the figure defines the colour
of the reverse side:
1=white 2=cream 3=brown
For the D grades, the figure describes the bulk
of the paperboard:
1=≥1.45cm3/g 2=<1.45cm3/g,>1.3cm3/g 3=≤1.3cm3/g
Paperboard
paperboardgrades
makingand
<< Contents
BarrierCoating
Barrier Coating 14<< Contents
BarrierCoating
3. Barrier Coating – Optimal Packaging Solutions using Barrier Coatings
StoraEnso’sbarriercoatingrangeisthewidestonthemarket,offeringsolutionsforpracticallyallpackagingneeds.Theroleofcoatinginthepackagingboardsistoproducethedesiredbarrierpropertiesforthepack-age,resultinginsuperiorproductqualityandprolongedshelf-life.Creativeuseofdifferentcoatings,togetherwithindividualmatchingofthemostsuitablebaseboardsforthepurpose,optimizespackageperformance,ensureshighvisualquality,savesmaterials,simplifiesconvertingandpackaging,andreduceswaste.
Barriercoatingstypicallyformatightfilmonthepaper-boardinordertoprovidethedesiredbarrierandotherfunctions.Generally,barriercoatinginpackagingboardsreferstotheuseofpolymersasextremelythinlayersonthebaseboard.Thesepolymersgiveexcellentproductprotectionpropertiesplussubstantialeconomicalandecologicalbenefits.Polymercoatingsproduceeffectivebarriersforawidevarietyofproducts,includingperish-ablefoodstuffs.
Themainpurposeofcoatingistoprotecttheproductfromtheundesirableeffectsofsuchfactorsaslight,oxy-gen,humidity,andmicrobes.Dependingontheapplica-tion,coatingfunctionsalsoincludeimprovedgrease-proofness,heatresistanceorpeelability,orenhancedprintingandfinishingproperties.
Application of coating polymers
Extrusionisthemostcommonlyusedbarriercoatingtechnologyforpolymerssuchas:
• PE(polyethylene),PP(polypropylene) andotherpolyolefins
• EVOH(ethylenevinylalcohol)andPA(polyamide) ashigh-barriermultilayercoatings
• specialpolymerssuchasPET(polyethylenetereph- thalate)andPBT(polybutyleneterephthalate).
Polymerscanalsobeappliedaswaterdispersionsbyusingtraditionalpigmentcoatingmethods.Anewgrouprapidlygaininggroundconsistsofbiopolymerstailoredforfullbiodegradability.
Structure of polymers e.g. polyethylene:
Polyolefin coatings
PolyolefinbarrierssuchasPE-LD,PE-HDandPPpolymersgivegoodhumidityprotection.Forheatresistance,PPcoatingissuperiorcomparedtothePEgrades.
Typicaluses:PEcoatedpackagesandcupsforbeverages,frozenfood,icecreamandyoghurt;PPcoatedpackages,traysandplatesforpreparedorsemi-preparedfoodssuitableformicrowaveheating;PE-HDcoatedpackagesformoisture-sensitivedryfoods.
15 Barrier Coating << Contents
Polyolefin coatings:
High-barrier coatings
PatentedEnsobarrhigh-barriercoatingsconsistofmulti-layerEVOHand/orPApolymerstructures.Theyprovideexcellentlight,oxygen,humidityandaromaprotection.EnsobarrSilvergradehasanadditionalsilver-colouredlayertoprovidemaximumprotectionagainstlight.Thehigh-barriercoatedboardsarealsogreaseproof.
Typicaluses:variousdelicatefoods,includingchocolate,cerealsanddairyproducts;dryfoods,suchascandy,savouryandprocessedsnacks,coffeeandtea,milkandcocoapowders;liquidproductssuchasjuices,softdrinks,greentea,water,soupsanddesserts,aswellaslight-sensitivebeveragessuchaswinesandlongshelf-lifejuices;non-foodproductssuchasliquiddetergentsandfabricsofteners.
High-barrier coatings:
Special Polymer Coatings
Specialcoatingscanperformbothbarrierandotherfunctions.TypicalexamplesarePETcoatingsthatprovideheatresistancetogetherwithexcellentgreasebarrierfea-turesandgoodWVTR(WaterVapourTransmissionRate)properties.PBTpolymersaresimilartoPETintheirfunc-tions,butenhancedwithexcellentreleaseproperties.
Typicaluses:Oven-usabletraysandreheatableproductpackages,andnon-sticktraysforbakeryproducts.
Special barrier coatings:
Biopolymer Coatings
Biodegradablecoatingsaretailor-madepolymersprovid-inghumidityandoxygenbarriersaswellassealability.Thecoatingcanbecompostedintohumusinorganicrecycling.
Biopolymer coatings:
BarrierCoating
Light
Oxygen
HumidityHeat,peelability
Grease
3
2
1
0
Light
Oxygen
HumidityHeat,peelability
Grease
3
2
1
0
Light
Oxygen
HumidityHeat,peelability
Grease
3
2
1
0
Light
Oxygen
HumidityHeat,peelability
Grease
3
2
1
0
Barrier Coating 16
Performance:1.Moderate2.Good3.Excellent
<< Contents
Paperboard
Recommendations
Handling
Paperboard Handling Recommendations 17<< Contents
Paperboard
Recommendations
Handling
4. Paperboard Handling Recommendations
Duetotheirstructure,allboardsare‘living’material.Anunwrappedsheetofpaperboardreactswiththeairveryquickly.Beforeprinting,youmustmakesurethattheinternalrelativehumidityandtemperatureofthesheetsareinbalancewiththeconditionsofthepressroom.Largedifferencesintheseparameterscanleadtoprob-lemssuchascurlingofthesheetsandslowinkdrying.
Makesurethatthepaperboardisacclimatizedtowhereitisgoingtobeprinted.Thenecessarytimeforsettlingcanbefoundonourpalletlabels.
Example:Ifthesize(volume)ofthepalletis1m3(1mx1mx1m)andthetemperaturedifferencebe-tweenthepalletandthepressroomis20°C,thesettlingtimeneedstobe46hoursinthepressroom.
Forpaperboard,theidealhumidityofboththeware-houseandthepressroomis50-55%relativehumidityandtheidealtemperature20-23°C.
Increasedrelativehumiditycancausedryingandrub-resistanceproblemsintheprintedsurface.Anotherpossiblereasonforslowdryingmaybeashortageoftheoxygenthatisneededforinkpolymerization.
Removethewrappingjustbeforeprinting.Thiswillensureevenandsmoothsettlingofthepallet.Thewrap-pingalsoprotectsthesheetsfromdirtanddamage.
pallet m3 Difference in temperature between the press room and pallet
5°C 10°C 15°C 20°C 25°C 30°0.3 7h 14h 21h 31h 43h 60h0.4 7h 17h 26h 36h 41h 64h0.6 9h 20h 31h 42h 55h 76h0.7 11h 21h 31h 44h 58h 79h1 12h 23h 33h 46h 62h 87h2 13h 24h 35h 49h 66h 90h
18 Paperboard Handling Recommendations << Contents
PrintingMethods
Printing Methods 19<< Contents
PrintingMethods
5. Printing Methods
Thefinalprintqualityisinfluencedbymanyvariables,suchaspaperboardproperties,printingpressandproc-essparameters,andinkproperties.Foroptimalresults,itisimportanttounderstandtheinteractionbetweenvitalpaperboardpropertiesandthechosenprintingprocess.
Thischapterdescribesthemostcommonprintingmeth-ods,althoughtheinformationbelowfocusesmainly
onthesheet-fedoffsetprocess,whichisthedominantprintingtechniqueforpaperboards.Theinformationwillfacilitatetheprocessingofourpaperboardsandenhancethequalityoftheprintwork.Moreover,theseguidelinesmayserveasatokenofourongoingendeavourstoaddourmanufacturingexperiencetotheexpertiseoftheprintingandconvertingindustries.
20 Printing Methods << Contents
Thedominantprintingmethodisoffset,whichisdividedintothreedifferentprocesses:
•sheet-fed(sheets)SFO forpaperandpaperboard •heatsetweboffset(reels)HSWO forpaperand low-grammagepaperboard •coldsetweboffset(reels)CSWO fornewsprint
Offsetprintingisbasedonphysicochemicalreactionsbetweentheink,fountainsolution,printingplateandblanket.
Theprintingplateismadeofaluminium.Theplateischemicallytreatedsothatimageareasacceptgreasyink(oleophilic)andarewater-repellent.Thenon-printingareasarehydrophilic,meaningthattheyrepelinkbutacceptfountainsolution.
Theaveragethicknessoftheinklayercarriedbytheplateis2-3µmandthatofthewaterlayer1-2µm.
Theinkistransferredfromtheprintingplatetotheprint-ingblanket,thenontothesurfaceofthepaperboard.
Thestructureoftheprintingblanketisatextureof2-4layerscoveredwithrubberlayers.Theblankethasdiffer-enthardnesslevels(70-85ShoreD),theharderblanketsbeingmoredurableandmeantforhigherprintingspeeds.Byusingasoftblanket,bettercontactwiththepaperboardcanbeachieved.Theblanketisnotallowedtoreactwithinksolventsduringtheprintingprocess.
Theprintingblankettransferstheprintingimagefromtheprintingplatetothesurfaceoftheprintingmaterial.
Theoffsetinksareverytackyandrequirehighsurfacestrengthintheprintmaterial.Thesheet-fedinksdrybyabsorptionandoxidation,heatsetinksbyevaporation(aidedbydryers).UV(Ultraviolet)offsetinksneedUVlighttodrybypolymerization.
Theinkingunittransfersaneveninklayertotheprintingplate,makestheinkfluidandflexibleandkeepsitatthecorrecttemperature.
Thefountainsolutionformsathinwaterlayeronnon-printingareasoftheprintingplate.ThepH,hard-nessandconductivityareimportantpropertiesforthe
fountainsolution.ThepHshouldbebetween4.8and5.3,hardnessbetween7and15°dHandconductivity50-200mS/mtoachievethebestprintingresult.
Sheet-fed offset printing unit
Waterless offset (dry offset)
Inwaterlessoffsetprinting,nowaterisinvolvedintheprintingprocess.
Inthedryoffset(waterlessoffset)process,moretackyinksareusedandspecialprintingplatestreatedwithsiliconeareneeded.Thesiliconematerialoftheprintingplatehasaverylowsurfaceenergyandmakesupthenon-printingareaoftheplate.Thismaterialwillresisttheink,providedtheink’sviscosityissuchthatithasagreateraffinityforitselfthanitdoesforthesilicone.
5.1 Offset printing
PrintingMethods
-dotsareuniformlycoveredwithink-edgesareragged
Printing Methods 21
Impressioncylinder/roller
Offsetblanketcylinder
Paper
Lithoplatecylinder
Waterrollers
Water
Inkrollers
<< Contents
-brokenshapeofdots-missingdots
-donutshapeddots
Temperaturecontrolofprintinginksisveryimportant.Thetemperatureshouldbestable.Theoptimumtem-peraturerangefordryoffsetinksisnarrowerthanforconventionaloffsetinks.Ifthetemperatureistoolow,theviscosityoftheinkincreases,resultinginpoorfluid-ity/rheologyoftheinkandinferiorinktransfer.Inprintedareas,thisresultsinpicking,ghosting,mottling(uneven-ness),lowprintedglossandproblemsresultingfrompoorinktransfer.Ifthetemperatureistoohigh,theinkviscositydecreases,causingsomeoftheinktobetrans-ferredtotheunprintedareasoftheprintingplate,result-ingindoublingproblems(dyetoning:weakerghostdotsnexttotruedotswhosepositionisoutofregister).
Theoperatingtemperaturerangesfordryoffsetinksare26-35°Cforblack,24-31°Cforcyan,22-28°Cforma-gentaand20-29°Cforyellow.Theexacttemperaturesdependonthemanufactureroftheinkandtheambientconditions.
WaterlessoffsetprintingisenvironmentallyfriendlierduetotheabsenceofwastewaterandresiduesfromIPA(isopropylalcohol)oradditives.
5.2 Gravure printingGravureisusedforlongprintrunsonpaperboard,mag-azinepaperandplasticfilms,andforsecurityprinting.
Theprintinginkistransferredfromtheprintingcylindercellstothesurfaceoftheprintingmaterial.
Gravure printing
Themetallicprintingcylinderandsoftrubberbackingrollformtheprintingnip.Thepressureattheprintingnipishightoensureoptimalinktransfer.
Themostimportantrequirementfortheprintmate-rialissmoothnesstoensuregoodcontactbetweenthepaperboard,theinkandtheprintingcylinder.Becauseofthehighpressureattheprintingnip,thecompressibilityofthepaperboardisalsoimportant.
Theprintinginkissolvent-orwater-basedwithaverylowviscositylevel.Theinksdrybyevaporationinthedryingunit.
PrintingMethods
Imageelementsareequallyspacedbutdifferinareaandvolume(variabledepthandvariablearea)
Impressioncylinder/roller
Blade
Inkfountain
Gravurecylinder
Gravurecylinder
Impressioncylinder/roller
22 Printing Methods << Contents
PrintingMethods
Theprintinginkistransferredbyananiloxrolltotheprintingplate.Thesurfaceoftheaniloxrollisfullofsmall,engravedcellsandextrainkiswipedawaybyusinganoscillatingdoctorbladeorachamberdoctorblade.
Theprintingplateismadeofphotopolymerorrubber.Theupliftingpartsoftheprintingplatetransfertheinkfromtheplatetotheprintingmaterial.
Thesoftprintingplateandhardsteelbackingrollformtheprintingnip.Thepressureattheprintingnipshouldbeverylight(“kiss”).
Theflexoinksarewater-orsolvent-basedwithaverylowviscositylevel.UVinkscanalsobeused.
Water-andsolvent-basedinksdrybyevaporationinadryingunitthatnormallyfollowseachprintingunit.UVinksneedUVlighttodrybypolymerization.
Thesurfaceenergyplaysanimportantroleinflexoprinting.Thesurfaceenergyshouldincreaseinprintingorder(lowerforinkthanforprintingmaterial)toensureoptimalinktransferandadhesion.
Flexoprintingismainlyusedforprintingonflexiblepackaging,labels,paperboardandflutingboard,plasticbagsandnewsprint.
-inkispressedtoedges-shadowintheedgeoftext
Flexo printing
Impressioncylinder(hard)
Printingplate(soft)
Elasticprintingplatewithraisedimageelements
Printingsubstrate
Aniloxroller
Inksupply(Chambereddoctorbladesystem)
InkedupimageelementCellsoftheaniloxrollerfilledwithink
5.3 Flexo printing
Printing Methods 23<< Contents
The main components in a printing ink are:
• Pigmentthatcreatesthecolourandcolour strengthandgivestheinkitsopticalproperties • Binderthatbindsthepigmentsintotheprinting materialandaffectsinkdryingandinkgloss • Solventthatadjustsinkviscosityandhasanef- fectoninksettinganddrying.Thesolventdissolves thebinder • Additives(dryer,wax,antiskinningagent,anti- foamingagentandsurfactants/flexo,gravure)
Sheet-fedoffsetinksdrybyoxidation+absorptionandheatsetoffsetinksdrybyevaporation.
OffsetUVinksdrybypolymerization.TheinkcontainsphotoinitiatorsthatabsorbUVemission.Theinkmono-merhastoreactwithUVemission.Dryingprogressesthroughtheinklayerfromtoptobottomandisdepend-entoninklayerthicknessandinktype(darkorlightinkshade).
OffsetUVinksareslightlytackierthantheconventionalinks,whichmeansthatthepaperboardneedsahigherdegreeofpickingresistance.NoodourortaintproblemsnormallyoccurwithUVinksifthedryingcapacityandtimeareoptimal.TheUV-printedsurfaceisnowreadyforfurtherprocessing.
Flexoandgravureinkscanbesolvent-orwater-basedandbothinksdrybyevaporation.
Metallic inks for offset
Theamountofmetalpigmentinsilverinksis25-30%andingoldmetallicinksupto50%.Themetalsusedingoldinksarecopperandzinc.Thegoldcolourshade(copperredtogreenishyellow)isdependentontheproportionsofcopperandzinc.Aluminiumisusedinsilverinks.
Theplatymetalpigmentsareproducedusingtheballmillprocess(goldandsilver)orthefoilprocess(silver).Theparticlesizeofthemetallicpigmentislargerthanthatofconventionalinkpigments.
Allmetallicinkshavegoodcoverage.Themetallicinkdriesthroughabsorptionandoxidation.Thesettingof
theinkdoesnotdifferfromconventionalinks.Whenmetallicinksareused,thefountainsolutioncanbethesamekindasforconventionalinks.
Theadhesionofmetallicinkstotheprintedbaseisweakerduetothelowerbinderamountandhigherpig-mentamountintheink.However,theseareknownfactswhenusingmetallicinks,andanyproblemsarecausedbytheinks,notbythepaperboardtobeprinted.
Ifthebaseboardisveryroughorhasveryhighporos-ity,itshouldbesealedbeforeprintingwithmetallicinks.Thetechniqueknownasunderprintingcanalsobeused.Underprintingwithyellow,redororangeinkcanbeusedundergoldink,andcyaninkundersilverinks.Theshadeoftheinkwillremainunchangedandtherub-offresistancewillbeimproved.
Thebestpaperboardgradeformetallicprintingispro-ducedinneutraloralkaliprocessestoavoidinkshadedifferences.Printingwithmetallicinksisbestdoneinthelastprintingunit.
Therubresistanceofmetallicinksislowerthanwithconventionalinksbutcanbeimprovedbyvarnishingtheprintedsurface.
A typical procedure when using metallicinks is as follows:
• metallicink+varnish • sealingofbaseboard+metallicink+varnish (whenthebaseboardisveryrough) • underprintingofbaseboard+metallicink+ varnish(shadeofinkandrub-resistance willbebetter)
Theadhesionofvarnishtothesurfaceofthemetallicinklayerispoor,partlybecausetheinklayerisslippery.Themetallicinkshouldnotcontainwax–oratanyrateaslittleaspossible.Theinklayershouldbethoroughlydrybeforevarnishing,toimproveadhesion.Theamountofvarnishusedshouldalsobeaslowaspossible.
Thebestvarnishingprocessforametallicinklayeris:metallicink+water-basedvarnish+UVvarnish.
5.4 Inks
PrintingMethods
24 Printing Methods << Contents
PrintingMethods
5.5 Digital Printing
Traditional and Digital Production Printing Technologies
Page description file
Ripping (Raster Image Processing)
Film processing
Plate making Plate/master manufacturing
Printing using a non-variable master
Offset, Gravure, Flexo
ElectrophotographyInkjet
ElectrocoagulationIonography
Magnetography
Computer to film Computer to plate/master Computer to plate
on pressComputer to press
Digital Printing
Adigitalprintingsystemcanbedefinedasasystemthatprintsimagesdirectlyfromrippedinformationwithoutastaticmaster,sothateveryconsecutiveprintcanbedifferent.Untilrecently,electrophotographywastheonlytechnologyusedinproduction-typecolourdigitalprint-ingmachines,butnewsolutionsforproduction-speeddigitalcolourprintingarebeingdeveloped,basedontechnologiessuchasink-jetandelectrocoagulation.
Digitalprintingisgraduallyenteringthefieldofcon-sumergoodspackaging.Promisingnewtechnologiesarebeingdiscoveredandexistingtechnologiesarebeingrefined.Here,twoofthemostcommondigitalprint-ingmethodsarediscussedbrieflyandsomecommentsaregivenregardingthespecialrequirementsforeachmethod.
Electrophotography
Paperboardgradesworksatisfactorilyinavarietyofsheet-orweb-fedelectrophotographicproductionma-chines.Eitherdirectorindirectdrytoner,oralternativelyindirectliquidtoner,canbeused.MachinesuppliersinthedrytonercategoryarePunchGraphix(Xeikon),Xer-ox(DocuColor,iGen3)ande.g.Kodak(NexPress),andintheliquidtonercategory,Hewlett-Packard(Indigo).
Ingeneral,itcanbesaidthatpaperboardrunsbetterindrytonermachinesinwhicheitherindirectorsingle-stepdirecttonertransferisusedandthepathfortheboardinsidetheprintingmachineisasstraightaspossible.Mostproductionprintingmachinesareincludedinthiscategory.Moreproblemscanarisewithsomehome,smallofficeornetworkprintersinwhichtoneristrans-ferredtotheboardinseveralseparatestepsandthepathfortheboardisnotasstraight.Inthiscategory,compat-ibilityshouldbeevaluatedineachseparatecase.
FortheHPIndigopress(liquidtoner),theboardsurfaceneedstobetreatedwithprimerpriortoprinting.Thetreatmentcanbeappliedwithaflexographiccoat-ingorprintingunitorwithanoffsetprintingmachine.Theprimersolutionshouldbeusedasreceived.Thetreatmentlastsfor2-3months.Excessivelyhighprimerconcentrationsreducethedurabilityandimpairliquidtonercompatibility,whichmaycauseyellowing.
Inkjet
PaperboardsarehighlysuitableforprintingwithUVinkjetinksandforone-colourinkjetprinting(black).Thecompatibilitywithotherinkjetinksdependsontheinkcompositionandshouldbeevaluatedcasebycase.
Printing Methods 25
Oneclassificationofthetraditionalanddigitalproductionprintingtechnologies.
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5.6 Practical printing instructions
PrintingMethods
Choose the right inkChoosingtherighttypeofinkisimportant.Thefollow-ingcriteriamustbetakenintoconsideration:
• desiredprintgloss • processing/convertingoftheproduct • dryingtimeoftheink • desiredscuffresistance • numberofcolourunits • possibilityofIR/UVdrying • tack • specialfeaturesrequiredfromthejob (odour/taintetc.) • subsequentUVvarnishing
Certainpropertiesoftheinkdependoneachother.Themostimportantoftheseareprintgloss,settingspeed,scuffresistanceandageinginthepress.Thesepropertiesarecloselyinterrelated.Forinstance,ifahigh-glossinkischosen,moretimehastobereservedfordrying.Formoredetailedinformation,itisbesttocontacttheinksupplier.
Amount of fountain solution during printing
Theentireoffsetprocessisbasedonthebalancebe-tweeninkandwater.However,asmuchas30%ofthefountainsolutionmayemulsifyintotheinkinnormalprintingcircumstances.
Thereisnobenefittousinganexcessiveamountoffoun-tainsolutioninthepress.Itquicklyaffectsthequalityoftheendproduct,causing,forexample,dryingproblems,printglossreductionandweakercolours.Whentheamountoffountainsolutionisincreasedduringprint-ing,italsoincreasestheamountofwateronthesurfaceofthepaperboard,eitherintheinkorontheunprintedareas.Thecorrectfountainsolutionlevelexistsonthepresswhenthereistheminimumpossibleamountofwaterontheplatestoachieveanoptimumprintingresult(adequateinkfilm)andwhenthefountainsolu-tionpHiscorrect,i.e.4.8-5.3.Undertheseconditions,thepaperboarddoesnotabsorbanexcessoffountainsolution,fromeitherunprintedorprintedsurfaces.
Furthermore,thisensuresquickinkdrying,thedesiredprintglossandthecorrectcolourbalanceontheprintedsurface.
Amount of inkInkdensityisoneofthemostimportantfeaturesmeas-uredfromtheprintedsurface.Rememberthatprintcontrastisreducedifexcessiveinkiscarried.Inkfilmthicknessalsohasaninfluenceontheinkdryingtimeandontheriskofset-off.Duringprinting,thecontrastofeachcolourshouldbemaximizedbyattainingtheopti-maldensitylevel.Thesmallertheamountofinkneededtoachievemaximumcontrast,thefinerthescreenthatcanbeusedinreproduction,resultinginthesharpestpossibleimageinthefinalproduct.
Drying of the ink
Dryingofstandardsheetfedoffsetcoloursisaffectedbyachemicalreaction.Ifyouwanttospeedupdrying,theprintedsheetscanbeacclimatizedbyturningthem,eithermanuallyorusingapileturner.
The reason for a drying problem may be:
• toohighhumidityinthepressroom • temperaturechangesinthepressroom • tooshortasettlingtimeofpalletsbeforeprinting (thematerialiscoldormoist) • unsuitableinkorinkseriesforthepaperboard beingused • excessiveamountofwaterorink • fountainsolutiontooacid • IR(infrared)dryertemperaturetoohigh
ThedryingofUVinksstartswithinafractionofasecondduetopolymerization.Thesheetsarereadyforfurtherprocessingimmediatelyafterprinting.
26 Printing Methods << Contents
PrintingMethods
Grain direction (Machine direction)
Thedirectioninwhichmostfiberslayinafinishedsheetofpaperboardisreferredtoasgrain.Fibersflowparalleltothedirectioninwhichthepaperboardtravelsontheboardmachineduringmanufacture.
Theenduseoftheproductmustbetakenintoconsider-ationwhenchoosingthegraindirection.Itisimportanttoknowhowtheendproductwillbeusedandwhatrequirementsarerelatedtoitsfunction.Forexample,thedirectionofascoreorfoldortherequiredsturdinessoftheendproductshoulddeterminethegraindirectionwhenthesheetsareordered.
Anotherimportantfactorforchoosinggraindirectionistheprintingpress.Almostwithoutexception,therun-nabilityofthepaperboardisbetterifprintedwiththegraindirectionparalleltothecylinders.Thepaperboardismoreflexibleinthesharpcurvesofthepressandproblemscanbeavoidedevenathighspeeds.Thisfac-torbecomesevenmoreimportantwhenthegrammageofthepaperboardishigher.
Moisture
Rememberalsothatthemoistureappliedinthepressincreasesthedimensionsofthesheet.Becauseofthestructureofthepaperboard,thefibresgenerallyexpandmoreindiameterthaninlength.Itisobviousthatifthegraindirectionofthesheetisthesameasthedirectionofprint,aregisterproblemcanoccur.Thelikelihoodofthisproblemoccurringisgreateriflargeformatsaretobeprintedwithaverypreciseregister.Toavoidsuchproblems,theorientationofthesheetshouldbeplannedbytakingintoconsiderationboththeendproductandtheprintingpress.
Printing Methods 27<< Contents
Converting
Converting and Finishing 28
andFinishing
<< Contents
6. Converting and Finishing
Paperboardpackagingoffersmarketersand
theirdesignersanincomparablecreative
medium.Thisisimportantwhenitcomes
tocommunication,positioningandbranding.
Astrongconstructionacceptsattention-
grabbingembossingwithoutcracksorbreaks
andapolishedfinishmeldswithfoilsand
hologramsforvibrancyanddepth.Theskillful
useoftheseprintingenhancementsin
paperboarddesignhelpstoattractconsumers
andoftenaddsvaluetotheproducts.
6.1. Varnishing
Varnishingimprovesthevisualappearanceoftheprintedsurface.Varnishesmaybemattorglossy.Spot-varnish-ingcanalsobeusedtohighlightcertainareasandmakethemmoreprominent.
Thevarnishshouldberesistanttomechanicalrubbingandsolvents.Aglossyvarnishlowersthefrictioncoef-ficient(COF)ofthepaperboardwhichshouldbehighenoughinordertosecuregoodrunnabilityofthepa-perboardinthefollowingconvertingprocess.NormallywhenhavingmattvarnishtheCOFlevelishigh.
Thefinalglosslevelofthevarnishedsurfaceisdepen-dentonpaperboardproperties,thethicknessofthevarnishlayerandthechemistryofthevarnishused.Iftheporesinthecoatinglayeraresmall,thevarnishhasdifficultypenetratingintothecoatinglayerandtendstoremainonthesurface.
Ifthesurfaceisveryrough,twovarnishlayersareneeded;thefirstoneclosesthesurfaceandthesecondonesmoothesouttheroughness.
Solventsinthevarnishshouldnotreactwiththecoatingbinderortheinkbinder,sincesuchareactionmayresultinsofteningofthevarnishedlayer.
Yellowingofthevarnishedlayercanbepreventedbychoosingtherightbindersystemforthevarnish.Varnish-ingwillimprovetherub-resistanceoftheprintedsurface.Varnishingcanbecarriedoutbyusinganinkunit(offsetvarnish),onlinevarnishunit(flexounitforwater-basedvarnish)oraseparatevarnishunit.Glueingshouldbecarriedoutonunvarnishedareas.
On-line varnishing can be divided into three main methods:
Offset varnish • composedlikeoffsetinks,butwithoutpigment • 1-2g/m2asdry • approximately75%solidcontent • chemicaldrying(oxidation)
Water-based varnish • approximately40-50%solidsacryldispersion • 2-5g/m2asdry • physicaldrying(IR,air=>evaporation+ penetration)
UV varnish • driesbyUVradiation • 3-8g/m2asdry • virtuallytheentirecoatingsubstancepolymerizes intoasolidfilm
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The advantages and disadvantages of each method are as follows:
+processedlikeink,+easytodospotvarnishing,+goodmoistureprotection
-slowdrying,-thinlayer,-riskofyellowing,-requirespowdering,-lowgloss,-odourandtasteproblemsmayoccur
Offset varnish
+goodgloss
+verygoodabrasionresistance
+fastdrying
+littleornoset-offpowderneeded
+highpilingstability
+noyellowing
+neutralodour
(dependentondryingconditions)
- spotapplicationmorecomplicated
- riskofsheetstretchorshrinkagewithlower
grammagesduetothehighwatercontent
- smearingbecauseoftoohighvarnishamount
ortooeffectivedryingpower
Water-based varnish
+processedlikeink
+easytodospotvarnishing
+goodmoistureprotection
-slowdrying
-thinlayer
-riskofyellowing
-requirespowdering
-lowgloss
-odourandtaintproblemsmayoccur
Offset varnish
+ thehighestgloss
+ veryhardandresistant
+ instantlydry
+ noset-offpowderneeded
+ veryhighabrasionresistance
- highcostofvarnishandenergy
- nottotallyodourless
(dependentondryingconditions)
- difficulttoprocessonlinewithconventional
inks(->adhesionproblems)
- yellowingofvarnishovertime(canbeavoided
byusingwaterbasedvarnishasprimerand
increasingtheviscosityofUVvarnish)
- varnishmayirritateeyesandskin
UV varnish
IfUVcoatingisappliedoverconventionaloffsetinks,theinksurfacemustbeabsolutelydrybeforecoating,and/orthe
inksmustbecarefullyselected.Otherwise,theresultmaybealowercoatingglossorflakingofthecoatedsurface.
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6.2 Embossing
Embossingisdonetoemphasizeprintedareaorprintimpressionorevenunprintedsurface.
Required paperboard properties,if all other properties are the same, then
• chemicalfibreisbetterthanmechanicalfibre • longfibresarebetterthanshortfibres • highermoistureisabenefit(inhibitscracking) • thickpaperboardisbetterthanthin • strengthproperties,especiallyburstingstrength, areimportant • thecoatingshouldbeflexibletoavoidcracking • multi-layerboardsarebetterthansingle-layer boards
Althoughabulkypaperboardmightseemeasiertoemboss,theaimisusuallytoachieveacertainheightsothattheembossingismorepronounced.Abulkypaper-boardwillrespondinamorespongyway.High-densityboardsgivemorepronouncedembossing(atthesametoolheight).
Theembossingmachinemustbecorrectlyadjustedforthepaperboardgradetobeprocessed.
Hot-foilisatechniqueusingverythinaluminiumfoilinavarietyofmetalliccolours,suchasred,blue,silverorgold.Themetallicfoilis(loosely)fixedtoacarrierfilm.Atoolbearingtheimagetobehot-foiledstrikesthisweb.Throughheatandpressure,theimageistransferredtothepaperboard.
Careshouldbetakenwhenapplyinghot-foilstampingonvarnishedpaperboard.Forbestresultsthefoilneedstoadherestronglytothesubstrate.Thepresenceofanykindofdebrisordirtwillhaveanegativeinfluenceontheendresult.Theprintingandcoatingthereforeneedtobeflawlessandadherestronglytothepaperboard.
31 Converting and Finishing
6.3 Hot-foil Stamping
Convertingand Finishing
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6.4 Die-cutting and creasing
Introduction
Characteristicsdifferbetweendifferenttypesofpaper-boards,suchassolidbleachedpaperboard(SBS),foldingboxboard(FBB)orwhitelinedchipboard(WLC).Allgradescanbecutandcreased,buttoobtainthebestresultforeachapplicationitisimportanttofine-tunethetreatment.Theoperatingwindowofdie-cuttingandcreasingvariesaccordingtothetypeofpaperboardanditsindividualproperties.
Itistrueofallpaperboardtypesthatresultsdifferdependingonthegraindirection,moisturecontent,thickness,andtheamountandtypeofsurfacetreatment(pigment,plastic,foil,etc.).Moisturecontentandthick-nessarethemostimportantfactors.Toollifewillalsobeaffectedbythepaperboardtypechosen.
Forcuttingandcreasing,therearebasicallytwometh-odsinuse:RotaryorFlat-bed.Thesedifferentmethodsplacedifferentdemandsonthepaperboard.Themaindifferencebetweenthemis:
- In rotary cutting, the knife does not meet the “anvil.” There is a gap of some 5 microns.
- In flat-bed cutting, the knife should just touch the counter plate for best results.
Inaddition,flat-bedcuttingcanbeperformedeitherin-lineoroff-line.Allofthesevariableswilltosomeextentplacedifferentdemandsonthepaperboard.Forrotarycutting,thewebmuststicktogether,ratherthanfallapart,untiltheblanksenterthesplitter/collector/stacker.Atthesametime,cleancutsaredesired.Thiscanbeachievedbyusingspeciallyadaptedqualities,butspeedofthedie-cuttingequipmentisofcoursealsoimportant.
Inoff-lineflat-bedcutting,almosttheoppositecouldbesaidtobetrue.Whilecleancutsarestilldesired,thepaperboardshouldseparateeasilyinthepuncher.Thefollowingdescriptionmainlyfocusesonflat-bedcutting.
Die-cutting
Agoodcutshouldbecleanandfreefromloosefibresandparticles.
Themostimportantstrengthpropertiesofthepaper-boardaretearandtensilestrength.Thesepropertiesdifferbetweendifferentpaperboardtypesandthedie-cuttingprocesshastobeadjustedaccordingtothoseproperties.
Thecorrectmoisturecontentisessentialforbothrun-nabilityandqualityduringthedie-cuttingprocess.Toohighalevelwillmakethepaperboardstronger,tougherandmoredifficulttocut.Toolowamoisturelevelwillmakethepaperboardmorebrittleanddifficulttotrans-fer,andmaycausedusting.Difficultiesincuttingmaybecausedbythepaperboardthickness,moisturevariationortoolwearandadjustments.Itisimportanttocontroltheclimatetokeepthemoisturecontentunchanged.Controlledclimatehelpstoachieveapreciseregisterbetweentheworkstages.
Ifthecuttingknivesaresharpandmeetthecounterdiecorrectly,thecuttingoccursasdesired.Aproblemmayoccurifthesheetmovesduringtheprocess.Thisisoftenduetoincorrectrubberingandresultsinflakingandpre-maturetearingofthebacklayerofthepaperboard.Thisisobservableasatornareanexttothecut.Damagewillalsooccurtotheknifeifitpressestooheavilyagainstthemetalplate.Theknifewearsandbecomesblunt,leadingtodustandhairy-cutedges.
Plastic-coatedorlaminatedproductswithanextratoughlayer(forinstancePET)shouldpreferablybedie-cutfromtheplastic-coatedside.
Creasing
Acreaseformswhenpaperboardispressedintoagroovewitharule.Thiscausesaplasticdeformationinthepa-perboard,allowingthepaperboardtofoldeasilywithoutcracking.Agoodcreaseissufficientlydeepandnarrowtoenableprecisefolding.Themainfactorforsettingtheadjustmentsisthethicknessofthepaperboard.Thetypeofthepaperboardisalsoimportant.Obviouslythepres-sureofthedie-cutteralsoaffectsthecreasing.
Converting and Finishing 32
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Duringcreasing,thepaperboardisweakenedinwell-de-finedfoldinglines,whichthenactashingesforfoldingpackagingandgraphicalproducts.Creasingiscarriedoutbyusingathinstripofsteelwitharoundsmoothedgeandanaccuratelycutgrooveinathinhardmate-rialknownasthecounterplate.Thecreasingrulepushesthepaperboardintothegrooveofthecounterplate,locatedunderthepaperboard,creatingapermanentcrease.
Agood,functionalfoldoccurswhenthepaperboarddelaminatesinthecreaseintoasmanythin,undamagedlayersaspossible.Plybondstrengthmustbeacompro-mise,sothatdelaminationoccurseasilyinacreasewhilethestructureholdstogetherinotherareas.
Thickerboardsrequireawiderruleandgroove.Bulkyboardsareeasytocrease.Creasingrequiresaflexiblecoatingandstrongsurfacelayers.Thefibrecomposi-tionandnumberoflayersareimportant.Amultilayerstructureincreasingisdesirable.Becausethickmaterialcannotfoldwithoutbreakingthestructure,thefibrelayersdelaminateinacrease.Thebondingbetweenthelayersweakensincreasing,causingthemtoloosenfromeachothermoreeasilyinfolding.
Thecreasabilitypropertiesdependonthefibreorienta-tion.Acreaseinthemachinedirectionusuallyhasworsefoldingproperties,becausethestiffnessislowerinthecross-fibredirection.Stablemoisturecontentisimpor-tant,becausedrypaperboardcancrackmoreeasily,whilemoistpaperboardhasalowerstiffness,resultingindifficultieswithdelamination.
Thecreasingpropertiescanalsobeanalyzedbymakinga“creasingwindow.”Atlaboratoryscale,theMarbachequipmentisusedbychangingthegroovewidthanddepth,blade/rulewidthandthepenetrationofthecreas-ingruleintothegroove.Thebendingforcesofcreasesaremeasured.Thecreasesshouldhavecertainstiffnessafterbending–inMD(machinedirection),45-60%andinCD(crossdirection),55-65%.
Avisualjudgmentofcreasesisalsomade.Ifthepaper-boardhasalargeoperatingwindow,thecreasabilityisgood.
Ingeneral,plasticsurfacelayersimprovethecreasability,becausetheyhaveverygoodelongationbeforetheybreakandtendtoreducetheriskofsurfacecrackinginthecreases,comparedwithplainpaperboard.
a=creasinggroovewidthb=creasinggroovedepthc=boardthicknessd=creasingruletipthicknesse=creasingruleheightf= thicknessofgroovebottom
creasingcounterpart
creasingplate
c
d
e
a
f
b
Creasing
33 Converting and Finishing
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6.5 Glueing
Sideseamorpointglueingisoftenthefinaloperationinthecarton-makingprocess.
Themostcommongluetypesusedforpackagingpur-posesarewaterbaseddispersionandhot-meltglues.Set-tingofthegluesproceedsbychemicalreaction,coolingdownorreductionofsolvent.
Thegluecanbeappliedusingagluewheel/diskoranozzlesystem.Water-basedgluesareappliedusingbothsystems,whilehot-meltglueisappliedbynozzles.
Whenthedelamination(breakdownoftheseam)occursinthefibrelayer,theseamisacceptableassumingthein-ternalstrengthofthepaperboardisonacceptablelevel.Ifitbreaksinthecoatinglayer,theremaybeaproblemduringuse.Delaminationinthegluelayerisatheoreticalpossibility.
Thesmoothnessandporosityofthepaperboardsurfacehaveaneffectonthemechanicaladhesionoftheglue.Theglueshouldbeanchoredtothepaperboardsurface.Theabsorptionofthetopandreverselayersmustnotbetoodifferentsincethiswouldresultinpenetrationofthegluemostlytothehighlyabsorbentside.Thegluemustwetthesurfacesproperly.Forprintedandvarnishedsur-faces,theseamareasareoftendevoidofinkandvarnishtoassistadhesion.Itisimportanttocorrectlyadjusttheglueingmachinesettingstothemostsuitableopentime,compressiontimeandforce.
Normallythegluesarewater-baseddispersionsofpoly-vinylacetate(PVAc).Themostimportantparametersforglueabilityarethepaperboardandthegluetype.Surfaceenergyandsmoothnessplayanimportantrole.Thesurfaceenergyofthepaperboardsurfacemustbehigherthanthatofthegluetoensuregoodadhesion.
Withplastic-coatedsurfaces,thecoronatreatmentisusedtoincreasethesurfaceenergyofthesurface.Thelowerlimitforsurfaceenergyofthepaperboardsurfaceseemstobe38mN/m–anythinglowermaycauseproblems.
Theamountofglueappliedisdependentonthepaper-boardandgluetypes–varyingwiththeglue’sviscosityforexample–aswellasontheapplicationsystem(diskornozzle).
Thegluedriesasthewaterpenetratesintothepaper-boardsurface.Penetrationisdependentonthemoistureandporosityofthepaperboardsurface.Aportionoftheglueitselfshouldalsopenetrateintothepaperboard.Therecommendedpenetrationdepthis1-3timesthefibrediameter.
Hot-meltgluesareusedtogluematerialswithalowporositylevel(plasticcoatingsandmetalliclaminates)orinprocessesthatrequireshortsettingtimeoftheglue(e.g.in-lineglueinginpackagingmachines).Hot-meltgluecontainsresin(affectingadhesion),wax(creatingasuitablerheologyforthemeltedglue)andpolymer(forcohesion).Hot-meltglueismeltedandappliedtothesurfaceatatemperatureof120-200°C.Whenglueingplastic-coatedboard,thegluemustbesohotthatitwillmelttheplastictosomedegree.Careshouldbetakenwhenusinghot-meltgluesincoldsurroundingsorundercoldconditions.
Converting and Finishing 34
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6.6 Lamination
Itistosomedegreeincorrecttotalkaboutlaminationasacomponentoffinishing.Paperboardisoftenboughtbyaconverterandlaminated,thensoldtoaprinter.Ifthisisthecase,therearebasicallytwomainapplicationsforlamination.Bothofthemtypicallyinvolvepaperboardinreels:
• Laminationofpolypropylene,aluminiumfoilor metallizedpolyesterfilmontoapaperboard • Laminationofoneormoreboardstoacore-web ofpaperboard,foamorsimilar
Theideaofthefirstprocessisoftentogivealuxuriouslookafterprintingonthepack.Theotherapplicationismoretypicallyintendedtoproduceadisplaypaperboardforadvertisingpurposes.Inthissecondlaminationproc-ess,twoormorewebsaregluedandpressedtogethertoobtainapaperboardgradewithahighergrammagelevel.Asdescribedabove,acentrelayerofsometypeisoftenincludedtogiveathickproduct.
The lamination may be:
• waxlamination (moltenwaxisappliedtothepaperboardsurface) • gluelamination (twoormorewebsaregluedtogether) -wetlamination -drylamination -solventlesslamination • extrusionlamination • hotmelt
Waxorresin-modifiedwaxisusedasahot-meltadhesiveinwaxlamination.Thewaxisheated,appliedtothesurfaceandcooled. Inwetlamination,oneofthewebsmustbeporoustoensureabsorptionofthesolvent,whiletheotherwebmaybeporousmaterial,aluminiumfoilorplasticweb.
Indrylamination,thegluelayerisdriedafterapplica-tion.Drylaminationcanbecarriedoutbyhotlamina-tion.Thedriedgluelayerisstickyathightemperaturesafteremergingfromadryingunit.Extrusionandhot-meltlaminationarehotlaminationprocesses.
Nosolventsandnodryingareusedinsolventlesslami-nation.Theadhesivesare100%solidmaterials,usedinsingle-componentortwo-componentsystems.
Theglueinwetlaminationisnormallywater-basedPVAcglue(solidcontentabout50%).Thegluedriesthroughabsorptionofthewaterbythepaperboardsurface.Nodryingunitisneeded.
Itisrecommendedthatthepaperboardbesheet-cuton-linejustafterthelaminationtoavoidcurlingproblems.
Itisalsoimportantthatthewebstobegluedtogetherhavesimilarcaliperandgrammageprofiles.Smooth-nessofthepaperboardisoftenveryimportantintheseprocesses.Otherfactors,suchastheglue,willalsoaffecttheendresult,butasmoothpaperboardhasahigherchanceofdeliveringthedesiredresult.
Thepaperboardsurfacemustbesufficientlyabsorbenttoensurethepenetrationofthegluesolvent.
Paperboardcanalsobegluedontoamedium(otherpaperboard,foam,etc.)assheets.Thisisnormallydoneafterprintingandtheprocessisknownaspastingorpaper-lining.Inotherwords,theprocessisdifferentbuttheendresultmaylooksimilar.
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Enduses
End uses 36<< Contents
Enduses
7. End uses
StoraEnsoConsumerBoardsisthemarketleaderinitsfield.Weproduceawideselectionofpremiumboardsineverycategoryandprovidethelargestvarietyofbarriercoatings.
Top-qualitymaterialsandinnovativesolutionsopti-mizetheperformanceofeachindividualpackageinitsparticularuserenvironmentandmarketingsituation.ConsumerBoards’offeringisbasedonend-useorientedbusinesscompetence,backedupbyinnovationandlo-gisticssupportthroughourInnoCentrefacilityandotherpartnerservices.
Forthebrandowner,designer,converterorprinter,thesuperiorityofpaperboardassuchisnottheheartofthematter.Thepackagingrequirementsforluxurycosmeticsarequiteunlikethoseforoven-to-tablefrozenfoods.Itisaquestionoffindingthecombinationofpaperboardproperties,gradeandgrammagethatwilloptimizetheperformanceofeachindividualpackage,whethertherequirementsaresuperiorstiffness,creasability,odourandtaintneutrality,ageingresistanceorsuperiorhotfoilstamping.
Product NamesBeverage &Multipack
Chocolate &Confectionery Cigarette
Cosmetics & Luxury
Detergent & Household
Aurocard
Chromocard
CKB
CosmocartT
Cupforma
Ensocard
Ensocoat
Ensogloss
Koppargloss
Kopparprint
Kopparwhite
Microliner
Natura
Neocart
Performa
Printocart
Tambrite
Tamfold
Tamwhite
Trayforma
TriplexBlanco
TriplexGris
TriplexMadera
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Understandingthecustomer’sbusinessismorethanaubiquitousbusinessphrase.Itisthemostimportantsinglecatalystbehindinnovativepackagingsolutionsandproactivepartnerservice.Therefore,theorganiza-tionofStoraEnsoConsumerBoardsisbasedontheBusi-nessSegmentManagementprinciple,whichcombinesproductionefficiencyandproductstreamliningwithend-user-drivenbusinessconcepts.
Allourcustomersareservedbydedicatedteams.ThemajorendusesservedbyStoraEnsoConsumerBoardsarepresentedbelow.Byclickingonaspecificproductinthetable,youcandownloadthelatestproductspecifica-tions(requiresinternetconnection).YoucanalsoaccessthesameinformationbygoingdirectlytoConsumerBoards’websiteatwww.storaenso.com/consumerboards.
Product Names Food Food Service Graphical Liquid Media Pharmaceutical
Aurocard
Chromocard
CKB
CosmocartT
Cupforma
Ensocard
Ensocoat
Ensogloss
Koppargloss
Kopparprint
Kopparwhite
Microliner
Natura
Neocart
Performa
Printocart
Tambrite
Tamfold
Tamwhite
Trayforma
TriplexBlanco
TriplexGris
TriplexMadera
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7.1 Graphical
Workingwiththegraphicalindustryisauniqueexperi-ence.Youenteranenvironmentwheretheprinter’sex-actingprofessionalismismatchedonlybythedesigner’sboundlessimaginationincreatingevernewsolutionstocapturetheinterestandacceptanceofthetargetaudi-ence.
More strength and durabilityStoraEnso’sgraphicalboardsaremadebycombiningvariouspulpsintomultilayerconstructionsinordertoutilizethebestpropertiesofindividualpulps.Thistech-nologygivestheboardstheirsturdyandrigidstructure,unattainableincorrespondingwood-freecoatedpapers.Asaresult,ourgraphicalboardshavepreciselytherightstrengthandstiffnessforoptimalperformanceduringtheprintingandsubsequentfinishingstages.Sturdyboardsalsogivesuperiordurabilityinfinaluse.
Thisexcellentperformanceisfullycompatiblewithim-provedeconomy.Comparedwithalternativesolutions,StoraEnsoGraphicalBoardsproducesafinalproductwithconsiderablylesstotalweight,resultinginmoreproductsfromlessrawmaterial.
Smooth and efficient finishingOurgraphicalboardsarefullycompatiblewiththemate-rialrequirementsofvariousfinishingmethods.Theyaresuitedtovarnishingtreatments,aswellasdie-cutting,embossingandcreasing.
Wide spectrum of paperboard optionsStoraEnsooffersacomprehensiverangeofproductsforthegraphicalindustry,fromWLC(white-linedchip-board)throughFBB(foldingboxboards)andadvancedmultilayerCTMP(chemi-thermomechanicalpulp)boardstoSBS(solidbleachedsulphate)boards.Whatevertheapplication,thereisanoptimalchoiceavailable,de-signedforthebestinsmoothnessandbrightness,print-abilityandrunnability,andconsistenthighqualityfrombatchtobatch.
Applications
End uses of Stora Enso Graphical Boards
• Coversformagazines,books,brochures, annualreports,maps,notepads,andmanuals
• Cards:greetingcards,postcards,collectingcards, recipecards
• Media:audioandvideoCD/DVDpacks,display boards,ticketsandtags,calendars,folders
BackedupbyServiceCentreswithhighsheetingcapacityandavailableviaanactivenetworkofspecializedmer-chants,StoraEnsographicalboardsarefullyequippedtomeetthedemandsoftoday’sfast-movingandrapidlydevelopinggraphicalindustry.
Formoreinformation,visitourdedicatedsiteatwww.storaenso.com/graphical.
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7.2 Beverage and Multipack
Packaging BeveragesThebasicfunctionsofpackaging–toprotect,distrib-ute,inform,attractandsell–alsoapplytobeverageproducts.However,theworldofbeveragesisuniqueinitsabundanceandvarietyofproducts,withthemostex-clusiveliquorbrands,backedbyhundredsofyearsofhis-tory,coexistingwithfashionablesportstonicslaunchedonlyyesterday.Paperboardcartonsinbeveragespackag-ingofferauniquecombinationofbrilliantimagingqual-ity,functionality,versatilityandcost-effectiveness.
ApplicationsStoraEnso’sbeverageandmultipackboardsareusedforsecondarypackaginginvariousconstructionsandset-ups,ofwhichthemainstreamvariantsare:
• Solidcartonsmadeofhigh-caliperpaperboard • Laminatedcombinationsusingtoplinersand stiffeners • Litholaminationtoasingle/doubleface corrugatedbase
Foilormetallizedfilmlaminationisemployedinalargeportionofapplications,especiallyforpremiumbrands.
Beverage cartonsTypicalproductgroupsforsingle-packcartonsarewhis-ky,spirits,liqueurs,wineandchampagne.Inindividualapplications,elaborategraphicsandfinishingtreatments(embossing,hotfoilstamping,spotvarnishing,etc.)oftenplayamajorrole.
Solidcartonsareusedforallprincipalproductgroupsofalcoholicbeverages,whilelaminatedandlitholaminatedcartonsarepredominantlyusedforcognacs,cham-pagnesandwines.
Bag-in-boxapplicationscontainingupto3litersofwinehavequicklycapturedalargeshareofsales,especiallyinthelowandmedium-pricedcategories.Thebasicconstructionhasgreatpotentialforfurtherrefinementandnewdesigns.
MultipacksBeermultipackshavefirmlyestablishedthemselvesasjustthetooltoattractsupermarketbuyersandsecuremaximumturnoverfromminimumspace.That,how-ever,isnotthewholepicture.Adaptabletoindividualneeds,distributionmethodsandmarketingstrategies,multipacksworkforamultitudeofproductsandmar-kets.Theeye-catchingpackislightandstrong,andeasytobuy,carry,openandrecycle.
Thesuitabilityofpaperboardforinnovativeconstructionsandnovelpackagingconceptsisamajormarketingas-set,evidentinsuchbestsellersasmultipacksforbeerandliquorandingeniousbag-in-boxwinepackages.
Agenerousprintingareaandexcellentfull-colourqualitymakepaperboardcartonsbothaglobalbrandingtoolandasuperbvehicleforcommunication,abletocreateenhancedshelfpresenceandlong-termcustomerloyalty.Moreimportantstill,paperboardcartonsofferawealthofoptionsforpromotionalusesandsegmentation,localizationandtestingpurposes.
Thecrucialfactoristoknowwhatpaperboardpackagingcandoandhowtoinitiatetheinnovativeprocess.
TolearnmoreabouthowStoraEnsodoesthis,accessthePartnerServicessectionatourwebsite.
Tofindclearanswerstoahostofindustry-specificpack-agingissuesvisitwww.storaenso.com/beverage.
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41 End uses
7.3 Chocolate and Confectionery
Aboxofassortedchocolatesismorethanaverypracticalcontainer.Itisasignal,apromise,apersonalmessage.Nowonder,then,thatthepackageismadeoffibre-basedpaperboard–amaterialthatcombinesrationalfunctionalitywithseductivecharm.
ApplicationsPackagingsolutionsbasedonStoraEnso’schocolateandconfectionerypackagingboardscomeinavarietyofinnovativeforms,designsandsizes,madepossiblebythematerial’suniversalapplicabilitytoawholerangeofconverting,printing,finishingandfillingmethodsandtechniques,aswellasanumberofadvancedbarriercoatingoptions.Everyindividualpackagingprojectsetsitsowndemands.Asaruleofthumb,paperboardpropertiesthatplayacrucialpartintheselectionprocessinclude:
• organolepticperformanceformaximumsafety andusersatisfaction • opticalpropertiesandprintqualityforoptimum shelfpresenceandbranddifferentiation • convertibilityandrunnabilityfortrouble-free production • per-unitcost-efficiencyforprofitablepackagingof relativelylow-pricedproducts.
Odour and Taint PerformanceThesensoricsafetyofStoraEnsopackagingboardsrestsonfourpillars:
• purityofthebaseboards • barrierpropertiesofproprietarypolymercoatings • trackrecordovermanyyears • in-housetesting,researchanddevelopment
Purity, Cleanliness, Homogenous Quality ThecoresegmentofStoraEnsochocolateandconfec-tioneryboardscomprisesSBSbrandsproducedfrompurepulp,aswellasarangeofboardswithCTMPaddedforextrastrengthandyieldandthetraditionalFBBgrades.ThechoiceisextendedbytheWLCrangemadeofrecycledfibres,elaboratelyrefinedandtestedforuseindemandingfoodpackagingapplications.
Polymer CoatingsStoraEnsobaseboardscoatedwithproprietarybarriersubstancessuchasPE,PETandHighBarrierpolymerspreservetheoriginalflavouroftheproductandprovideprotectionagainstundesirableeffectscausedbylight,oxygen,humidityorgrease.
Matchingthemostsuitablebaseboardwiththeproperbarriercoatingisaperfectwayofmaintainingsuperiorproductqualityandprolongingshelf-life.
Forconsultationontheplanningandimplementationofyourownpackagingprojects,pleasecontactus.Also,ourdedicatedInternetsiteoffersacomprehensiveviewofpackagingbasedoninnovativeuseoffibre-basedmaterials.Formoreinformationvisitwww.storaenso.com/chocolate.
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7.4 Cigarette
StoraEnsoCigaretteBoardsoffersawideandcost-effec-tiverangeoftobacco-packagingsolutions.Theprod-uctofferingincludesFBB(FoldingBoxboard),CTMP(chemi-thermomechanicalpulp)andSBS(SolidBleachedSulphate)optionstomeetallneeds.Thewideselectionprovidestherightboardchooiceforthedesiredposition-ingofanindividualcigarettebrand.
Just-in-timedeliveriestoprintersaresecuredbyfourhighlyefficientmillsinthreecountries.TheservicesarebackedupbyvariousR&Dprojectswhichsupportbrandownersandprinterstocreatesuperiorproductdesignsandapplications.
Findinganoptimalboardmaterialisfacilitatedwhenalloftheoptionscanbeobtainedfromasinglesource–amajorbenefittocustomers.Astrongpartnershipbetweenbrandowners,printersandStoraEnsoenablesthemostcost-efficientsolutionstobefoundandappliedinallareasofthevaluechain.
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43 Enduses
7.5CosmeticsandLuxury
Finding an optimal carton material for packaging cos-metics and perfumes is a demanding task where general rules of thumb are not easy to find. However, some of the key points are listed below for easy reference in order to ensure that the package fulfils its major functions – protecting the contents throughout the supply chain, attracting potential customers and building distinctive brand images.
StrengthandstructureformaximumprotectionAbility to withstand mechanical stress – vibrations, impacts, blows and bumps – is an absolute necessity for cosmetics cartons. The inner structure of the material must be such that the various layers of the paperboard do not become delaminated under any circumstances. For perfume cartons, on which solid printing, heavy tints and colourful graphics are often used, the paperboard’s structure must provide excellent smoothness as well as superior cracking resistance at the fold.
HighwhitenessforsuperbvisualimageHigh whiteness ensures good contrast in printing – im-perative for top-quality results. Furthermore, whiteness associates strongly with desired product features such as purity and cleanliness. If the package design employs large unprinted areas, high whiteness of the paperboard becomes all the more important.
A significant feature relating to whiteness is the paper-board’s ability to withstand UV radiation without yellow-ing. This is a vital consideration, especially if the carton is to be exposed to sunlight for extended periods.
FullchoiceofprintingandfinishingoptionsThe quality of the carton must mirror or even enhance the quality of the contents. Printing techniques should include offset, flexo and gravure. Suitability for digital printing is also rapidly gaining weight.
More important still is the possibility to use a whole range of finishing treatments and special effects, such as pearlescent pigment printing, satin UV varnish, glossy hot-foil stamping, positive blind embossing, or laser cutting. Depending on the design, the visual appearance of the paperboard’s reverse side and its printability can also be decisive factors, taking into consideration that on cosmetics cartons there is usually a need for a lot of product information.
OdourneutralityThe carton must be very neutral in its organoleptic prop-erties to ensure that, even after extended storage, no undesired odours will be emitted from the paperboard. Only the desired fragrances, those of the product itself, must be there for the consumer to enjoy.
For more information visit our dedicated site at www.storaenso.com/cosmetics.
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7.6 Detergents and Household
Packagingsolutionsmustservemanyends.Theproductontheshelfmustbehighlyvisibleandrepresentativeandalsocommunicatehighquality.Atthesametime,itisimportanttoproduceecologicallysoundpackagingwithoutsacrificingsuchvitalfunctionsasproductsafetyanduserconvenience.Paperboardisuniqueinitsabilitytosatisfytheseconflictingrequirements.Paperboardcartonsarelightweightandstrong,functional,eye-catchingandascost-efficientinproductionastheyareinrecycling.
StoraEnsoistheworld’sleadingproducerofpackagingpaperboardanddeveloperofnewpackagingconcepts.Ourproductrangeissecondtonone.Atoneendoftheproductspectrumarethehouseholdproductpackag-ingboards,whichcanbefoldedintoanendlessvarietyofshapes.Attheotherarethedetergentpackagingboards,whosekeydevelopmentprincipleisusersafety.Inbetweenthetwoextremesisawiderangeofprod-ucts,varyingintherawmaterials,strengths,mechanicalproperties,bleachingdegreesandsurfacefinishesused.
Allhouseholdpackagingboardsareavailablewithap-propriatepolymercoatings.MaterialoptionsalsoincludeLumiLabelflexiblepackagingpapersaswellascorru-gatedpackaging.
Forconsultationonthechoiceofmaterialorotherpack-agingissues,pleasecontactus.
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45 End uses
7.7 Food
Thereisnosubstituteforfibre-basedpaperboardasthebestmaterialforimaginative,excitingandfunctionalfoodpackaging.Paperboardissmoothandstrong,lightandbright,versatileandcost-efficient.Itlendsitselfper-fectlytoalltheshapes,sizes,designsandconstructionsthatdifferentproductsandmarketsituationscallfor.Thematerialisalsoidealtousewithmetaldetectorsandothersafetymeasures.
ApplicationsPackagingsolutionsbasedonStoraEnsofoodpackagingboardscoveramultitudeofforms,designesandsizesinallmajorproductsegments:
• Chilled Foods: Vegetablesandsalads,meatand fish,processedfood,puddingsanddressings,etc.
• Frozen foods:Readymeals,fishandseafood,ice cream,bakeryproducts,etc. • Dry foods: Biscuits,cereals,candy,drinkpowders, teas,snacksandchips,spices,etc.
• Pet foods:Wet/drycatfoodsanddogfoods,etc.
Forprimarypackagingpurposes,vitalfactorsintheselectionofthepaperboardinclude: - Organolepticperformanceofthebaseboard/poly- mercoatingcombination - Opticalproperties(brightness,printability,smooth- ness,ageingresistance) - Convertibilityandrunnability(creasability,flatness, no-dustingperformance) - Strengthinrelationtothesizeandweightofthe contents(bendingstiffness,tearresistance, glueability)
Insecondarypackaging,cost-effectiveness,sourcereductioncapacity,stiffnessand,especiallyinthecaseofpromotionalpacks,suitabilityfordigitalprintingarepropertiesthatusuallyplayamoreprominentrole.However,everyprojecthasitsownspecificdemands.Forconsultationonyourspecificpackagingtasks,pleasefeelfreetocontactus.
The essential companion: barrier coatingsInfoodpackaging,preservingthefreshnessandpalat-abilityofeventhemostdelicatefoodsisanabsolutemust.Afullrangeofpolymercoatingsmakesitpossibletocreatecups,traysandcartonswhichperformoptimal-lyinspecificenvironmentsforspecificproducts.Ingen-iouscombinationsofbaseboardandcoatingcreateafullspectrumofeffectivebarriersagainstmoisture,oxygen,light,greaseorheat.
Readmoreaboutthefoodsectorandthemanyoptionsforpackagingfoodsatourspecialsite:www.storaenso.com/food.
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7.8 Pharmaceutical
Therangeofpharmaceuticalproductsisenormous,fromthemostpotentprescriptiondrugstoordinaryover-the-countermedicines.Accordingly,theroleofpackagingrangesfromensuringproductsafetyandpatientcompli-ancetoprovidingaversatiletoolforcommunicationandbrandbuilding.
ApplicationsStoraEnso’spharmaceuticalboardsareusedincartonsforallformsofprimarypackaging–aluminiumandcom-positeblisters,glassandplasticbottles,rigidandcollaps-ibletubes,andpouches.Ingeneral,cartonsforprescrip-tionmedicines(antibiotics,cardiacs,potentpainkillers,etc.)usefewercoloursandmoresubdueddesigns,whileOTC(overthecounter)products(vitaminsandmicronu-trients,painkillers,coldmedicinesandskincreamsetc.)investinattentionvalue,attractivedesignsandelaboratefinishing.
Sheetoffsetwithwater-basedvarnishisthedominantprintingmethod.
Basicvariabledata(lotnumber,use-bydate)isimprintedduringthepackingprocess,usingstamping,flexo,inkjetorlasertechniques.
NarrowWebflexoprintingwithinlineconvertingmaybeacost-efficientalternativeforsmallorderlotsandisalreadyappliedbyseveralconvertingcompanies.
Digitallyprintedcartonsarebeginningtogaingroundasaviablemarketingandtestingoption.
Thechoiceofpaperboardmaterialmustbemadeindi-viduallyineachcase.Typicalvariablesinclude:
• opticalproperties(brightness,printability, ageingresistance) • strength(bendingstiffness,tearresistance, glueability) • runnabililityinpackaginglines(creasability, flatness,no-dustingperformance,lasercodability) • qualityandhygieneconsiderations (materialconsistency,purity,cleanlinessand homogeneity,odourandtaintneutrality) • technicalsuitabilitytocase-specifictechnologies (digitalprinting,etc.).
Theapplicablegrammageisdeterminedbysuchfactorsasboxdimensions(biggersizesneedstifferpaperboardinordertoperformwellinthepackingprocess)andtheweightofthecontents(improvedcompressionresist-anceisneededforcartonscontainingheavyproducts,suchasliquidsinglassbottles).
Visitourwebsite,www.storaenso.com/pharmatolearnmoreaboutthepharmaceuticalpackagingmarkets,innovativepackagingconceptsandthechoiceofpaper-boardforindividualapplications.
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7.9 Food Service
Convenience for Food Service StoraEnsooffersafullrangeofadvancedmaterialsandintegratedsolutionsforthefoodservicemarketthatca-tertothemanydifferentneedsoftoday’sactiveconsum-ers,whetheritiseat-on-the-gooroven-to-tablemeal.
FoodServiceproductsderivetheirstrengthfromauniquematerialthatcombinesspecially-developedbase-boardsandproprietarypolymercoatingstocreatethebestqualityintermsofpurity,functionality,printabilityandconvertibility.
Formoreinformation,visitourdedicatedsiteatwww.storaenso.com/cupforma.
7.10 Liquid
Fluid Solutions, Full ProtectionTheoverridingrequirementforliquidpackagingistokeepthecontentsfreshandhygienic,unchangedand
untaintedfortheentirelifeoftheproduct.Thecartonmustalsobeattractive,buildbrandimageandboostsales.Inadditionitmustcomplywithtoday´sbestenvi-ronmentalpractices.
Readmoreaboutliquidpackagingatourspecialsitewww.storaenso.com/liquid.
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Servicefacilities
ConsumerBoardsProductionand
Stora Enso Consumer Boards Production and Service facilities 48<< Contents
StoraEnso
Servicefacilities
ConsumerBoardsProductionand
8. Stora Enso Production and Service facilities
StoraEnsoConsumerBoards’productsaremanufacturedinFinland,Germany,SpainandSweden.Thetotalan-nualcapacityofthesixmodernandwell-managedmillsiscloseto2.6milliontonnesofSBS,FBB,CTMP,SUB
andWLCgrades.ExtrusioncoatingplantsinFinlandandSwedencomplementtheproductionofbaseboardswithcomprehensivefacilitiesformoistureandoxygenbarriercoatings.
8.1 Paperboard Mills
Baienfurt Mill, Germany
BaienfurtMillproducespackagingboardsforavarietyofgeneralpackagingapplicationsservingcustomersinpharma-ceutical,cosmetics,confectionery,cigaretteandothermajorindustries.Inaddition,theBaienfurtofferingincludesaselec-tionofgraphicalboards.
Annualcapacity:205000tonsofFBB*Machines: BM3,machinewidth476cm
Barcelona Mill, Spain
BarcelonaMillproducesWLCboardsbasedonrecycledfibres.Theproductsofthemillserveagreatvarietyofmarketsfromfood,confectionery,detergentandpharmapackagingtobookcoversandlabellingapplications.
Annualcapacity: 170000tonsofWLCcoatedonbothsides*Machines: BM1,machinewidth400cm
Fors Mill, Sweden
ForsMillproducesfullycoatedfoldingboxboardsforvari-ousmarketsegmentsincludingchocolate,confectioneryandcigarettepackaging.
Annualcapacity: 380000tonsofFBBandCTMPboards*Machines: BM2,machinewidth372cm BM3,machinewidth543cm
49 Stora Enso Consumer Boards Production and Service facilities *)in2006 << Contents
Imatra Mills, Finland
PaperboardproductionatImatraMillscomprisesliquidpack-agingboardsforallpackagingsystems,cupstockandotherfoodserviceboards,packagingboardsforthecosmetics,food,confectioneryandcigaretteindustriesaswellasaselectionofgraphicalboards.
Annualcapacity: 930000tonsofSBS,LPBandCTMPboards* 280000tonsofpolymercoatedboards*Machines: BM1,machinewidth440cm BM2,machinewidth560cm BM4,machinewidth630cm BM5,machinewidth490cmCoatingmachines:PE2,machinewidth230cm PE3,machinewidth230cm PE5,machinewidth280cm
Ingerois Mill, Finland
IngeroisPaperboardMilloffershigh-bulkfoldingboxboardsforfood,healthcare,pharmaceutical,liquorandhouseholdindustries.
Annualcapacity: 205000tonsofFBB*Machines: BM4,machinewidth458cm
*)in2006 Stora Enso Consumer Boards Production and Service facilities 50
StoraEnso
Servicefacilities
ConsumerBoardsProductionand
Skoghall Mill, Sweden
SkoghallMillisalarge-scaleproducerofliquidpackagingboardsandthemultilayerkraftbackCKBconcept.
Annualcapacity: 745000tonsofLPB,FBB,WTLand CKBboards*Machines: KM7,machinewidth540cm KM8,machinewidth810cm
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8.2 Extrusion Coating Plants
Forshaga Mill, Sweden
ForshagaMillproducesarangeofbarrierpolymercoatingsincludingfoilandfilmapplicationonbaseboards.Typicalendusesincludeliquidcartons,foodpackaging,lunchboxes,noodlecupsandothercartonpackaging.
Annualcapacity: 140000tonsofmultilayerpolymercoated packagingboards*Coatingmachines: BL922,machinewidth200cm BL923,machinewidth200cm
Karhula Mill, Finland
KarhulaMillisspecialisedinco-extrusiontechnologycombin-ingdifferentpolymerstoproducepolymercoatedboardsforliquidandfoodpackagingapplications.
Annualcapacity: 45000tonsofmultilayerpolymercoated packagingboards*Coatingmachine: PE4,machinewidth201cm
51 Stora Enso Consumer Boards Production and Service facilities *)in2006
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Servicefacilities
ConsumerBoardsProductionand
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8.3 Partner Services
LocationofStoraEnsoServiceCentres
StoraEnsoConsumerBoards’partnerservicesfocusonpromotinginnovativenessandenhancingtheefficiencyandprofitabilityoffibre-basedpackaging,thusaddingpermanentvaluetoourcooperationwiththepackagingcommunity.
ServiceCentres for reliability and maximum efficiencyThemissionofStoraEnsoServiceCentresistomeetcustomers’individualmaterialneedswithmaximumef-ficiency,flexibilityandreliability.MajorEuropeanmarketsaresuppliedwithpromptdeliveriesofpremiumboardsandgradescomingfromvariousStoraEnsomills.TheServiceCentresarelocatedinthemiddleofmainmarketareasandequippedwithhigh-performancesheetingmachinery.
Basedonamassivesheetingcapacityof80tonnesperday, ServiceCentre BaienfurtinGermanyofferstheconceptof2-5servicing.Thismeansex-milldeliveriesofboardsfromBaienfurtandotherEuropeanmillswithintwoworkingdaysfromstandardsheetstocksandwithinfiveworkingdaysfromreelstocks.
ServiceCentre Cartiberia inSpainservescustomersinthegeneralpackagingandgraphicalindustrieswithboardsfromtheBarcelona,Ingerois,SkoghallandImatramills.TheServiceCentrehasastandarddeliverytimeofthreetofivedaysex-factory.
OtherServiceCentres areinoperationinGermany,Swe-denandtheUK.
InnoCentreInnoCentrepresentsanewinterfacetothefutureoffibre-basedpackaging.Onthestrengthofmajorinvest-mentsmadeinpeople,machineryandequipment,InnoCentrefunctionsasavehicleforverticalinnovation,proactivelytestingnewtechnologyanddevisinginnova-tivepackagingconcepts.Theresultsofthedevelopmentworkcantakemanyforms,includingimprovedlogisticssolutionsandnovelpackagingbusinessmodels.TheservicesofInnoCentreareavailabletoallourpartnersinthepackagingvaluechain.
PartnerWebPartnerWebisStoraEnso’sdedicatedonlinereal-timesoftwaresystemformanagingthesupplychain.Theso-lutionemploysanordinaryInternetinterfacetoaccessacustomer-specificapplicationthatletstheusertrackandmanagetheentireorder-to-deliveryprocess.PartnerWebisuseddailybyanincreasingnumberofourkeypart-nersforimprovedoperationalefficiencyanddrasticallyreducedroutinework.PartnerWebalsosupportsdirectsystemintegrationpossibilitiesutilizingPapiNetXMLmessaging.
Formoreinformationvisitourdedicatedsiteatwww.storaenso.com/partnerservices.
OSKARSHAMN
LUMIPAPER
CARTIBERIA
LÜBECK
BAIENFURT
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ConsumerBoardsProductionand
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TestingMethods
Testing Methods 53<< Contents
TestingMethods
9. Testing Methods
Thischapterdescribesthetestingmethods
usedfordifferenttypesofpaperboards.These
measurementsaremadeinordertoguaran-
teetheconsistent,highqualityofour
products.Inthemillenvironment,testingis
conductedusingonline,autolineandmanual
laboratorymeasurements.
Themostimportantroutinequalitycon-
troltestsofdifferentproductsaredescribedin
thischapter.
Testing standards and calibration
ThetestsapplytoISO,SCANandTAPPIstandardmethods.Ifstandardsarenotavailable,themill’sownmethods,ormethodsdevelopedincooperationwithcustomers,areusedtopredictthepropertiesoftheproduct.Testingisperformedusingmoderndevicesandmostofthetestsaremadeinstandardconditions.Thestandardconditionsare:23°Ctemperatureand50%relativehumidityaccordingtothestandardISO187(SCAN-P2:75).
Testing methods
Online testing
Onlinetestingisusedtomeasurethemostimportantpropertiesofthepaperboard.Themeasuringheadoftheprocesscomputermeasuresbasisweight,caliperandmoisturecontinuouslyfromeverymachinereel.Theonlinemeasurementprovidesdatathroughouttheentiremachinereelandenablesthemachinepersonneltocontrolthebasicpropertiesofthepaperboardsimultane-ously.
Themachinepersonnelchecktheentiremachinereelvisuallyateveryreelchange.Theyalsocheckimpurities,colourandformationfromthecross-profilesample.Theonlinemeasurementproperties–grammage,caliper,moistureandbrightness–arealsocalibratedortestedinthelaboratory.
Automated laboratory testing
Thereareautomatedlaboratoryteststations(laterreferredasAutoline)inthepaperboardlaboratories.Thesetestingdevicescanbeequippedwithinstrumentssuchas:
• Two-sidedgloss • Caliper(thickness) • Two-sidedsmoothness(PPS) • Two-sidedroughness(Bendtsen) • Porosity(Bendtsen) • Burststrength(Mullen) • Basisweight • TSO(TensileStiffnessOrientation)
TheAutolinemeasuringdevicesmeasureandmove30cm-widecross-profilesamplesautomatically.Theresultsaresavedinthecomputerandtransferredautomaticallytoaquality-datahandlingsystem.
Manual laboratory testing
Sheetsacrossthemachinereelaredeliveredtothelaboratoryformanualtestingbythemachineperson-nel.Thesizeofasinglesheetis30cmx30cmandthenumberofsheetsdependsonthewidthofthepaper-boardmachine.Testingisperformedsevendaysaweekinthreeshifts.
EverymachinereelistestedaccordingtotheproceduresdescribedintheISO9001system.Someoftheproper-tiesaretestedacrossthewebinmanypositionsandsomeinonepositiononly.Inqualitycontrol,mostofthetestsareperformedimmediatelyafterproduction,withoutairconditioning.
54 Testing Methods << Contents
TestingMethods
General properties
Grammage Unit:g/m2 ISO536:1995
Grammageisdeterminedbyweighingaknownareaofasample.ThegrammageismeasuredbothonlineandbyAutoline.
Thickness Unit:µm ISO534:1988 SCAN-P7:96
Thicknessisdefinedasthedistancebetweenthetwooutersurfacesofasinglesheetmeasuredat100kPapressureandovera200mm2testarea.Inadditiontotheonlinetesting,thicknessismeasuredbyAutoline.
Moisture Unit:% ISO287:1985
Moistureismeasuredbytheonlinetesting.Themois-turecontentisalsocheckeddailyinthelaboratorywithameasuringdevicethatusesmicrowavestodeterminethemoisturelevel.Inadditiontothesemeasurements,weeklycalibrationisperformedbydeterminingthelossofweightofsamplesdriedatatemperatureof105°C.
Physical strength properties
Stiffness (L&W) Unit:mN ISO2493:92 SCAN-P29:95
Stiffnessisdeterminedbymeasuringthebendingforcerequiredtodeflectasamplefromitsoriginalpositionwhenoneendofthesamplehasbeenanchored.Stiff-nesscanbemeasuredasbendingstiffnessDIN5°,bend-ingmomentTaberorbendingresistanceL&W15°.Forexample,intheL&Wbendingresistancetest,thebend-ingdistanceis50mmforpaperboardand10mmforpaper.Testingisconductedinbothmachineandcrossdirectionsbyastiffnesstester.TaberstiffnessismeasuredaccordingtotheTAPPI489standard.
Surface properties
Roughness (Bendtsen) Unit:ml/min ISO8791-2:1990
Roughnessisdefinedastheflowofairwhichleaksbe-tweenthesurfaceofasampleandametalringpressedagainstthesurfaceunderspecifiedconditions.Rough-nessismeasuredonbothsidesofthesheetandthetestiscarriedoutbyAutoline.
Smoothness (PPS) Unit:µm ISO8791-4/1992
IntheParkerPrintSurface(PPS)smoothnesstest,smoothnessisdefinedastheaveragedistancebetweenthepaperboardsurfaceandametallicringpressedagainstthesampleunderspecifiedconditions.Airflowsinsidethemetalring.Theairleakagebetweenthemetalringandthesampleismeasuredbyaflowmeter,whichconvertsthevaluetoµm.ThePPSsmoothnesstestingmethodprovidesmoreinformationaboutmicro-scaleroughnessthantheBendtsenmethod.
Porosity (Bendtsen) Unit:ml/min SCAN-P60:87 ISO5636-3:1992
Porosity(ml/min)isdeterminedbymeasuringtheamountofairthatflowsthroughagivenareaofthesample.
Testing Methods 55<< Contents
Optical properties
InEurope,theISOstandardisnormallyusedtomea-surebrightness.WhenthebrightnessisexpressedasISObrightness,C/2lightmustbeusedforthemea-surements.SinceC/2lightdoesnottakeintoaccounttheeffectsofOBA(opticalbrightener)anddyes,thismeasurementgiveslowerbrightnessvaluescomparedtomeasurementsusingD65light.D65brightnesstakesintoaccounttheeffectsofbothOBAanddyes.
TheCIEwhitenessmeasurementusesawiderwave-lengthandcorrespondsmorecloselytohowhumaneyesrecognizethewhiteness.
TAPPIbrightness,measuredwithGEequipment,isusedintheUS.
Brightness D65/10 Unit:% SCAN-P3:93
Brightness C/2° Unit:% ISO2470:99 (ISO–Brightness)
CIE Whiteness D65/10 ISO11475,SCAN-P66:93
L*a*b* D65/10 SCAN-P72
L*a*b* C/2 ISO5631
Opacity Unit:% ISO2471
Brightness(%)isdefinedastheintrinsicreflectancefactormeasuredataneffectivewavelengthof457nm.Formeasuringbrightness,D65/10°illuminationwithadefinedamountofUVlightisnormallyused.
Althoughtwosheetsmayhavethesamebrightness,therecanbealargedifferenceinvisualperception.Vis-ualdifferencescanbeestimatedfromdifferencesintheL*a*b*colourcoordinatesintheCIELABcolourspace.L*isthescaleforthewhitenessimpression,rangingfrom0(black)to100(white).a*measuresshadesinthered/greenarea.Positivea*indicatesred,whileanegativea*valueindicatesagreenshade.b*measuresshadesintheyellow/bluearea.Positiveb*indicatesyellow,whileanegativeb*valueindicatesabluishshade.
CIELAB colour space
TheL&WElrephomethodmeasuresbrightness,colourproperties,fluorescenceandmanyotheropticalproper-tiesbyusingdifferentlightsandangles.
Theamountofopticalbrighteningagentsisalsodeter-minedbycalculatingthedifferencebetweenbrightnessD65/10unfilteredandbrightnessD65/10witha420nmcut-offfilter.
Gloss (Hunter) Unit:% TAPPIT480om-99 ISO8254-1:1999
Thesurfaceglossofthecoatedpaperboardorpaperisdeterminedasthereflectanceoflightfromthesheetsurface.Thelightstrikesthesurfaceatanangleof75°andthereflectionisrecordedbyaphotoelectriccell.Theresultisexpressedasthepercentageoflightreflected.TheglossismeasuredbytheHunterGlossTesterintheAutolineandiscalibratedwithatestpieceofknownreflectivity.
TestingMethods
56 Testing Methods << Contents
Glossary
Glossary 57<< Contents
Technical Glossaryabsorbency: abilityofapaperboardtotakeupandretainaliquidwithwhichitisincontact
blade coating: mostwidelyusedcoatingmethod,inwhichexcesscoatingmaterialisscrapedoffbyablade
bleaching: removaland/ormodificationofcolouredcomponentsinpulptoimprovebrightness,carriedoutin
oneormoreconsecutivestages
broke: paperboarddiscardedduringmanufactureorconverting;usuallyrepulped
bulk, specific volume: reciprocalofpaperboarddensity,alsoknownasspecificvolume
calendering: operationcarriedoutbymeansofacalenderonthe,atleastpartially,driedpaperorpaperboard,
withtheaimofimprovingthefinish,theprocesspermittingsomecontrolofthethicknessofthe
paperboard
caliper, thickness: thicknessofpaperboard
chemical pulp: pulpproducedbyusingcookingchemicalswhichdissolvelignin,theglueinthewood,
toreleasethecellulosefibres
chemi-thermomechanical
pulp, CTMP: chemi-thermomechanicalpulp;pulpproducedbyrefiningchemicallyimpregnated,
preheatedwoodchips
China clay, kaolin: mineralusedinpaperboardmaking,asbothfillerandcoatingpigment
CIE whiteness: degreeofwhitenessmeasuredaccordingtorecommendationsoftheCIE
(CommissionInternationaledel’Eclairage)
CKB,
Coated Kraft Back Boards: paperboardconsistingofeitherbleachedchemicalpulporamineral-coatedtoplayerorboth,an
unbleachedbackandamiddlelayerofunbleachedchemicaland/ormechanicalpulp;usedfor
packagingfoodandnon-foodproducts
coating: processbywhichpaperboardiscoatedwithanagenttoimproveitsbrightnessand/orprinting
propertiesoritsbarrierproperties;layerofextrudedplasticonpaperboardprovidesbarrier
propertiesorgoodprintabilityforthesubstrate;layerofpigmentsandbindingmaterials,suchas
latexes,improvesprintabilityofpaperboard
CTMP, see: chemi-thermomechanicalpulp
deinked pulp, DIP: recoveredpaperpulpwhichhasbeende-inkedthroughchemicalormechanicalprocessing
digital printing machine: printingmachinethatprintsdirectlyfromacomputerdatafileontopaperboard,usingthesame
imagetransfertechniquesasareusedincopiersandprinters;oftenincludesbindingoperation
DIP, see: deinkedpulp
FBB, Folding Boxboard: multi-layerpaperboard,oftenmineral-coated,withanouterlayerofsulphate(kraft)pulpandmiddle
layerofmechanicalpulp(groundwood,pressuregroundwoodorTMP;intopgradesCTMPpulpmay
alsobeapplied);usedprimarilyforconsumercartonsforpackagingofdryormoistfoods,cigarettes
andotherconsumerproducts;alsousedinthegraphicalindustryforcataloguecovers,postcardsand
folders,etc.
Folding Boxboard, see: FBB
filler: substance(oftenwhitepigment)addedtothefurnishinordertoimprovepaperboardproperties
fully bleached pulp: pulpthathasbeenbleachedtothehighestbrightnessattainable
furnish: mixtureofpulpsandfillerswhichisprocessedbythepaperboardmachinetomakepaperboard
gloss finish: shinyandhighlyreflectivesurfacequalityofpaperboardobtainedbyglosscalendering
grade: classificationofpaperboardsdifferentiatedfromeachotheronthebasisoftheircontent,appearance,
manufacturinghistory,and/ortheirenduse
grammage, gsm: massofpaperboarddividedbyarea,typicallyexpressedasg/m2;oneofthebasicunitstospecify
apaperboardgrade
10. Glossary
Glossary
58 Glossary << Contents
gravure printing, rotogravure: printingprocesswheretheimageisengraved(electronicallyorchemically)intheformof
cellsinthesurfaceofametalcylinder
groundwood pulp, mechanical pulp: mechanicalpulpmanufacturedbygrindingwood,againstagrindstoneforexample
gsm, see: grammage
hardwood: woodfromadeciduousbroad-leavedtree(suchasbirch,oak,beech,aspenoreucalyptus)
asdistinguishedfromthatofconifers
ISO brightness,
diffuse blue reflectance factor: intrinsicreflectancefactorataneffectivewavelengthof457nm;measureforthebright
nessofpaperboard
kaolin, China clay: mineralusedinpaperboardmaking,asbothfillerandcoatingpigment
laminated: productoverlaidwithalayerofplasticfoilorveneer
lignin: polymerwhichbindsthefibresinthewoodtogetherandgivesthemstiffness
long fibre pulp: pulpproducedfromsoftwood(softwoodpulp)
matt finish: mattcalenderedsurfaceresultinginadullfinishtothesurfaceofpaperboardand
havingadiffusereflection;oppositeofglossfinish
mc, see: moisturecontent
mechanical pulp, groundwood pulp: mechanicalpulpmanufacturedbygrindingpaperboard,againstagrindstoneforexample
moisture content, mc: weightofwatercontainedinwood,expressedasapercentageoftheweightoftheoven-
drypaperboard
offset press: printingpressusinganoffsetmethod,wherebytheimageistransferredfromtheplate
cylinderontopaperboardviaablanket,plateorimpressioncylinder
opacity: propertyofpaperboardthatpreventsshow-throughofprinting,theoppositeof
transparency
optical characteristics: characteristicsoftheappearanceofpaperboard,themostimportantofwhichare
shade,brightness,opacityandgloss
permeability: abilityofasurfaceorcoatingofpaperboardtoallowpassageofagas,liquidorvapour
permeance, porosity: combinedvolumeofthepores,capillariesandothervoidsbetweenthefibresandfillersin
apaperboard
plastic coating and laminating: coatingofpaperboardbypolymers,typicallypolyethylene,and/orlaminatingwith
othermaterials,typicallyaluminiumfoil,plasticfilmorotherpaperboard
plate: anymaterialusedtomakeaprintedimpressionbyletterpress,gravureorlithography
porosity, see: permeance
press: setsofopposingparallelrollsinapaperboardmachinethroughwhichthepaperboardweb
passesduringmanufactureandbetweenwhichitissubjectedtopressure,atthesametime
increasingthedrynessofthepaperboard
primary fibre, virgin fibre: woodfibreneverbeforeusedtomakepulporpaperboard
printability: functionandinteractionofpaperboardwithothercomponents,e.g.theinkintheprinting
process;subjectiveassessmentjudgedfromtheprintingresultandcoveringallthepaper-
boardpropertiesthatinfluencetheresultsofprintinganimage.Compare:runnability
recovered paper: Usedpaperandboardseparatelycollectedforre-useasfibrerawmaterialinpaperand
paperboardmanufacture
reel-fed web offset printing: printingonacontinuousrollofpaperboardinaprintingpresswhichusesacurved
printingplatemountedontheplatecylinder(HSWO)
rotogravure, gravure printing: printingprocessinwhichtheimageisengraved(electronicallyorchemically)intheform
ofcellsinthesurfaceofametalcylinder
roughness: degreeofroughnessofthesurfaceofpaperboard;oppositeofsmoothness
Glossary
Glossary 59<< Contents
runnability: featurecoveringallthepaperboardpropertiesthatcreateatrouble-freerunthrougha
paperboardmachineorprintingpress(alsohowwellcartonsrunonanautomatic
packagingline);seeprintability
SBS, Solid Bleached Sulphate Board: paperboardconsistingofoneorseverallayersofbleachedchemicalpulp,oftenalso
pigmentcoated,usedinthegraphicalindustryandforvariousconsumercartonsfor
packagingdryormoistfoodproductsandinthenon-foodsector,typicallyforcigarette
andluxurygoodscartons
sheet-fed offset printing: offsetprintingwhereindividualpiecesofpaperboardarefedintothepress
short fibre pulp: pulpproducedfromhardwood(hardwoodpulp;e.g.birch,oak,beech,aspen,eucalyptus)
sizing: processwhereasizingagent(e.g.starch,ASA)isaddedtothepaperboardtoincrease
strengthanddecreaseabsorbance
smoothness: degreeofevennessandregularityofthesurfaceofapaperboardsheet;oppositeof
roughness
softwood: woodofpine,spruce,orotherconifers;withtheadvantageofhavinglongfibreswhich
enhancethestrengthofpaperboard
Solid Bleached Sulphate Board, see: SBS
specific volume, bulk: reciprocalofpaperboarddensity,alsoknownasspecificvolume
SUB (Solid Unbleached Board): paperboardusedforfoodandnon-foodcartons,consistingofableachedchemicalpulp
oramineral-coatedtoplayerorboth,anunbleachedbackandunbleachedchemical
and/ormechanicalpulpmiddlelayers
sulphate pulp, kraft pulp: chemicalpulpproducedbycookingwoodchipsinanalkalinesolutionofsodiumhydroxide
andsodiumsulphide
tearing resistance: mechanicalpropertyofpaperboard,forceneededtotearpaperboard
thickness, caliper: thicknessofpaperboard
TMP, thermomechanical pulp: mechanicalpulpproducedbythepressurizedpre-steamingofwoodchipspriortodefibra-
tioninarefiner
web fed offset printing, web offset: offsetprintingonarollofanysubstratethatpassescontinuouslythroughaprintingpress
White Lined Chipboard, WLC: paperboardmademainlyorwhollyfromrecoveredfibres,oftenmineral-coated,and
usedforconsumercartonsfordryfoodandnon-foodproductsaswellasgraphical
enduses
virgin fibre, primary fibre: woodfibreneverbeforeusedtomakepulporpaperboard
WLC, see: WhiteLinedChipboard
Glossary
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