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Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

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Page 1: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Fabricating and forming sheet

Durability, Sustainability, Flexibility

Page 2: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Contents

Fabricating and forming sheet 1

Generalhealthandsafetyprecautions 1

Storingandhandling 1

Cleaning 2

Sawing,routing,andlasercutting 2

Tipsforcutting 3

Drilling 5

Shearing,punching,anddiecutting 5

Bonding,fastening,andwelding 7

Tipsforbonding 11

Forming 12

Tipsforthermoforming 15

Decorating 16

Summaryoffabricatingandforming 18

Note: Conversion of metric/U.S. customary values may have been rounded off and therefore may not be exact.

Page 3: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Fabricating and forming sheet

EastmanSpectar™copolyester14471,alsoknownasPETG,

isaplasticresinspecificallydesignedforthicksheet

applications.ItisproducedinpelletformbyEastman

ChemicalCompany,andconvertedintosheetbyvarious

commercialextruders.

General health and safety precautionsSafetyAlwaysexercisegood,safeshoppracticeswhenfabricating

orformingsheetofEastmanSpectar™copolyesterand

otherplasticmaterials.Heatgeneratedduringsawing,

machining,finishing,andthermoformingoperationscan

burnunprotectedskin.Flyingparticlesandcontactwith

chemicalsandvaporsarealsoareasofconcern.Besureto

adherestrictlytoallinstructionsinMaterialSafetyData

Sheets(MSDS)providedbyequipmentandmaterial

suppliers.Inaddition,keeptoolssharpandingood

workingorderforsafeoperationandhigh-qualitywork.

VentilationItisalwaysgoodshoppracticetoworkinawell-ventilated

area,particularlywhensolventbonding,cementing,orlaser

cutting.Providelocalizedexhaustventingintheworkarea.

Protective equipment Alwaysuseappropriatesafetyequipment(goggles,gloves,

hearingprotection,etc.)whenhandlingplasticsheetand

operatingshopequipment.

Storing and handling Sheet stockHeavy-gaugeplasticsheetisgenerallyshippedincorrugated

cases,onpallets,orascontinuousrolls.Storelargesheet

flatwithmaskingintact.Sheetstoredonedgeinstorage

racksshouldhaveasupported,slightlyangledbackboard

(A-frame)topreventsheetfromwarping.Besurestorage

areasareclean,dry,cool,andwell-ventilated.Whenpossible,

rotateinventoriesonafirst-in/first-out(FIFO)basis.

MaskingSheetofEastmanSpectar™copolyesterisprotectedwith

amaskofpolyethylenefilm.Wheneverpossible,leavethe

maskingintactduringfabrication.Useolderstockfirst.

Also,avoidanyunsupportedoverhangofthesheetduring

storage.

Removeanymaskingadhesiveresidueonthesheetwith

aclean,softclothdampenedwitha50:50mixtureof

isopropylalcoholandwater.Ifthesheethasastaticcharge

afterremovingthemasking,wipethesheetwithaclean

clothslightlydampenedwithwatertohelpremovethe

charge.

Handling formed partsFormedpartswillcontinuetocoolaftertheyareremoved

fromthemold.Topreventdeformation,itisimportantto

providepropersupportduringcooling.Also,avoidany

unsupportedoverhangoftheflatsheetorformedparts.

Topreventdishing(becomingconcave),supportpartsalong

theiredges,facedown,untilcompletelycooled.Donot

nest-stackformedparts.

General handling and storage recommendations•Weargloveswhenhandlinglargesheetstopreventcuts.

•Keepmaskinginplaceforaslongaspossible.

•Keeptabletopscleantoavoidscratchingthesheet.

•Storesheetsflat,asdelivered,topreventwarpage.If

verticalstorageisnecessary,itisbesttostorethesheet

andformedpartsataslightanglewithfullsupport

underneath.

•Supportlarge,formedpanelsbytheiredges,facedown,

whilecooling.

•Storematerialindoorsinadry,cool,well-ventilatedarea.

•UsetheFIFOmethodtorotateinventory.

•Donotuseaknifeorscrapertoremovemasking.

•Donotstoreplasticsheetnearradiators,steampipes,or

indirectsunlight.

1

Page 4: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

CleaningDust and dirtRemovedustanddirtfromsheetofEastmanSpectar™

copolyesterwithasoftcottonclothandasolutionofmild

soaporliquiddetergentinwater.A50:50solutionof

isopropylalcoholandwateralsoworkswell.Remove

greaseandresiduefromtapeorpapermaskingwith

naphthafollowedbyawaterwash.Alwaysuseasoft,

dampclothandblotdry.Rubbingwithadryclothcan

scratchthematerialandcreateastaticcharge.Neveruse

scrapersorsqueegeesonSpectarsheet.Seeadditional

cleaninginstructionsonpage16.

Do NotUse a squeegee.Use strong solvents.Rub with a dry cloth.

Sawing, routing, and laser cuttingGeneral recommendationsIfpossible,leavetheoriginalmaskingonthesheetduring

cuttingoperations.Inaddition,coverworkingsurfaceswith

asoft,cleanclothtopreventscratching.

Usesharp,cleanblades,holdingthesheetsecurelyinplace.

Bringthebladetofullspeedbeforestartingthecutand

usecompressedairtocoolthebladeandremovechips.

Wearpropersafetyequipmentincludingsafetyglasses,

gloves,andprotectiveclothingasrequiredbyapplicable

regulations.

Saw and cutter typesMostsawscommonlyusedforwoodormetalshould

satisfactorilycutsheetofEastmanSpectar™copolyester.

Theseincludecircularsaws,bandsaws,sabersaws,jigsaws,

hacksaws,orhandsaws.However,circularsawsandband

sawsusuallyproducesmoother,cleaner,fastercuts.

Routingisalsoacommontechnique.

Forthehighestqualitycut,useatriple-chipstylecarbide-

tippedbladecommonlyusedforplastics.SeveralSpectar

sheetscanbestackedandcuttogetherbutonlyifthe

stackisheldsecurelytopreventmovementfromsheetto

sheet.Otherwise,chippingandirregularcutsmayresult.

Useaslowandconsistentfeedrate.

Blade characteristics Circular saws

•Numberofteeth—2to4teethper25mm(perinch).

•Bladethickness—2.5mm(3⁄#@in.)forsinglesheetsin

thicknessesof1to10mm(0.040to0.375in.);3-mm

(l-in.)bladeshouldbeusedforcuttingthickersheet.

•Bladetoothrakeangle—0°–5°.

•Depthofcut—forbestresults,allowthebladeto

protrudethroughthepiecebynomorethan3mm

(lin.).Thiswillminimizethechanceofcreatinga

chippededge.

•Forcircularsaws,thefollowingbladespeedsare

recommended.

Blade diameter, mm (in.) Blade speed, rpm

100(3.5–4)Trimmingsaw,usewoodcombinationblade

10,000

180(7d) 5,000

200(8) 4,300

250(10) 3,400

300(12) 2,900

350(14) 2,500

Band saws

•Numberofteeth—8to14teethper25mm(perinch)

forgeneralcutting;18to24per25mm(perinch)fora

smoother,cleaneredge.

•Bladewidth—forintricatecutsandtighterturns,

6to10mm(dtomin.)issuggested.Forstraightcuts,

largerturns,12to25mm(ato1in.)issuggested.

•Bladespeed—approximately760mm(2,500ft)

perminute.

Saber saws and jigsaws

Alwaysholdyourworksecurelyinplace.Thisisespecially

importantwhenusingasabersaworjigsaw.Excessive

vibrationcancausecrackingand/orpossibleinjury.

•Abladewith6to10teethper25mm(perinch)works

wellwiththeorbitalactionsettingatzero.

•Ascroll-typebladewith12to20teethper25mm

(perinch)canbeusedtoachieveagoodedgefinishon

intricatecuts.

2

Page 5: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Handsaws and hacksaws

AlthoughnotcommonlyusedonsheetofEastman

Spectar™copolyester,handsawsandhacksawscanwork

satisfactorilyifusedcarefullyandwithlittlepressure.Use

sharpbladesthatrangefrom6to18teethper25mm

(perinch),dependingonthedesiredfinish.Asalways,

securelysupportthesheettoavoidflexing.

Routers

Routingwithsharp,two-flute,carbide-tippedstraight

cuttersproducesverysmoothedges.Twistedtwo-fluted

cuttersworkexceptionallywell.Alsospiral-cutrouterbits

havebeenfoundtoworksuccessfully,dependingonthe

application.Itisespeciallyusefulfortrimmingedgesofflat

orformedparts,orpartstoolargeorirregularinshapeto

cutwithabandsaw.Portable,overarm,andsmalltable

routersworkequallywell.

•Userouterspeedsof18,000–32,000rpmtoproduce

good,cleanedges.

•Feedthesheetintotherouterslowlytoavoidexcessive

frictionalheating,shattering,orchipping.

•Useasuitablejigtosupportthesheetduringrouting.

•Usecompressedairtocoolthebitandtoaidinchip

removal.

Laser cutting

EastmanSpectar™copolyestercanbelasercutusingthe

sameequipmentasthatusedforcuttingacrylic.Typically

lowerpowersettingsandslowercuttingratesarerequired

whencuttingSpectarsheetvs.acrylicsheet.Itisalso

recommendedthatacuttingtablewithgoodvacuum

ventilationbeutilizedtoremovetheby-productscreated

duringthecuttingprocess.ThisappliesforbothSpectar

andacrylicsheet.

Eastmaniscurrentlyworkingwithlaserequipmentto

betterunderstandthelasercuttingsystemwhenworking

withSpectarsheet.PleasecontactEastmantechnical

serviceforfurtherupdates.

Tips for cutting Eastman’srecommendationsarebasedonexperience

workingwithsheetofEastmanSpectar™copolyester.They

canbeusedasastartingpointorasguidelinesforcutting

theseproducts.

•Usetoolsdesignedforplastic.

•Usesharpblades:Jigsawsshouldbeequippedwitha

scroll-typebladefordetailworkandacoarse-toothed

bladeforbetterchipremovalonheavierwork.Forcircular

saws,acarbide-tipped,triple-chiptoothpatternis

recommended.

•Holdsheetfirmlywhilecuttingtominimizevibration,

especiallyforthinnergauges(<120mil).

•Keepfeedrateslowandconstantwhencutting.

•Donotreversethenaturalcurveofthematerialwhen

cuttingsheetfromrollstock.Thisoverstressesthesheet

andcancausefractures.

3

Router speeds of 18,000–32,000 rpm should produce good, clean edges.

Page 6: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Operation Type of equipment Recommendations

Trimming

Routerbitsd-inchminimum,single-ordouble-flutedup-spiralbitsarerecommended,3–4flutedforlargerbits(i.e.,Onsrud#52-624).

Routerblades4-Wingcarbidetip,slottingcutter(i.e.,WhitesidePart#6700B),>20Krpm,slow/medcutspeed

Jigsaw Recommend10teeth/inchforsmoothestcut

Bandsaw Recommendminimumof6teeth/inch

Circularsaw(3.5–4-diameter)

Carbide,triple-chiptoothcutrecommendedifcanfind,otherwiseuseawoodcombinationblade(i.e.,Makita),2mm-rake,>10Krpm.

Circularsaw,7-diameter 60-toothcarbide-tippedblade,triple-chiptoothcutifpossible

Roto-ziptypeZB10bitforsmalltrim(<=0.150-sheet),Onsrud#52-624for(>=0.150-sheet)

KettsawBlade#157-66,2.5,80teeth,rateofcutwilldeterminequalityofcut,keepsharpbladetopreventmeltingplastic

Drilling Drillbits Thosenormallyrecommendedforplastics

Recommendations for cutting sheet of Eastman Spectar™ copolyester

Problem Possible cause Possible solution

Roughorchippededges

HighfeedrateSheetvibrationBladeprotrusionBrokenteethBladetoocoarse

Reducefeedrate.Securesheetfirmly.Limittomaximumof3mm(l in.).Replaceblade.Usemoreteeth/in.(mm).

CrackingBladeandfencenotparallelSheetvibrationFeedratetoohigh

Realignbladeandfence.Securesheetfirmly.Reducefeedrate.

SurfacescratchingNomaskingDirtyworksurfaceJigs/fixturesarenicked,burred

Ifpossible,leavemaskingintact.Cleanworksurface.File,sand,orpolishtoremoveburrs.

Bladegumsup

DullbladeInconsistentfeedrateFeedratetooslowImproperblade

Sharpenorreplaceblade.Usesteady,evenfeedrate.Increasefeedrate.Usebladespecified.

Dustbuildup

DullbladeCloggedbladeStaticchargeonsheetMaskingremoved

Sharpenorreplaceblade.Cleanorreplaceblade.Wipewithdampcloth.Leavemaskinginplace.

4

Troubleshooting guide for cutting sheet of Eastman Spectar™ copolyester

Page 7: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Knife edge Hollow groundapproximately

Sheet thickness up to2.5 mm (0.100 in.)

5

DrillingDrills and bitsSheetofEastmanSpectar™copolyestercanbereadily

drilled,usingastandarddrillpressorhandhelddrillwith

sharp,cleandrillbits.Drillbitsdesignedforusewithplastic

arerecommended.Bitsdesignedforusewithpolycarbonate

havebeenfoundtoworkwellwithSpectarsheet.Standard

drillbitscan,onoccasion,beusedbutmayhavetobe

groundtoreducethedepthorangleofcut.Aswithany

plasticsheetproduct,itisimportanttokeepvibrationto

aminimumtopreventchippingorcracking.Holdthework

securelyinplacewhendrillingbutavoidexcessive

clampingpressure.

Drilling procedureOptimumbitspeed,feedrate,andappliedpressurewill

dependonholesizeandsheetthickness.Drillspeedsupto

1,750rpmarebestforsmallerholes,whilespeedsaslow

as350rpmcanworkforlargerholes.Usewateror

compressedairtominimizeheatbuildupwhendrilling

sheetsthickerthan4.8mm(0.187in.),stackedsheets,

orverylargeholes.

Whendrillingholesthatwillpenetratethesecondsurface,

backupthepiecewithwoodtocushionthedrillbitasit

passesthroughthesheet.Movethedrillbitinandoutto

removeplasticshards.

Avoidtoppingadrilledholeorusingself-toppingscrews.

Summary•Usesharpdrillbitsdesignedforplastic.

•Usejustenoughclampingpressuretopreventvibration.

•Usealoadspreadertodistributeclamppressureevenly.

•Usecompressedairtopreventoverheating,especiallyif

sheetismorethan4.8-mm(0.187-in.)thick.

Shearing, punching, and die cuttingGeneral recommendationsSheetofEastmanSpectar™copolyesterisatoughbut

ductilematerialandcanbesheared,punched,anddiecut

whenpropertoolsandtechniquesareused.Ashearcut

yieldsastraightedge,whilepunchesanddiescanbeused

toproduceholesofalmostanydesiredshape.

ShearingApowershearcanbeusedtocutsheetinthicknesses

upto2.5mm(0.100in.).Forthickersheet,sawingis

recommended.Toachievesmoothcuts,maintaina

blade-to-bedknifeclearanceofapproximately0.025mm

(0.001in.).Thefollowingdiagramshowsatypical

shearingassembly.

Thickness, mm (in.) Sheet shear strength, MPa (psi)

2(0.080) 57.6(8,354)

3(0.118) 56.5(8,195)

Shear strength requirements (ASTMD732,shearstrengthdeterminationmethod)

Shear strengthThefollowingtableshowsshearstrengthrequirementsfor

cuttingvariousthicknessesofsheetofEastmanSpectar™

copolyester.

Page 8: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

PunchingWhenaparticularlysharporsmoothcutisnotrequired,a

punchcanbeused.Hand-operatedpunchesareusefulfor

smallholes,butlargerholesmayrequireapower-operated

punch.Heatingthesheettoapproximately38°C(100°F)

willminimizethepossibilityofcrackingorchipping;

however,allowforholeshrinkageduetocooling.We

recommendsawing,drilling,androutinginsteadof

punchingsheetthickerthan2.5mm(0.100in.).

Die cuttingCut0.8-to2.5-mm(0.030-to0.100-in.)thicksheetof

EastmanSpectar™copolyesterwithsteelruledies.These

areusually12.5-mm(a-in.)deepandaremountedina

properlyshapedslotcutintoawoodenblock(seethe

followingdiagram).Whilerelativelyinexpensive,steelrule

diesmustbesharpenedorreplacedfairlyoftentoremain

effective.

Apply pressure

Knive edge

Hollow ground

approximately 30°

Cut 0.8- to 2.5-mm(0.030- to 0.100-in.)thick sheet of Eastman Spectar™ copolyester with steel rule dies.

Die press capacityAdiepressmusthaveadequatepowertoachievethe

desiredcut.Usetheshearstrengthsshownonpage5

withthefollowingformulatocalculatetherequired

presscapacity.

F=SXPXT

CF=Requiredpresscapacityintons

S=SheetshearstrengthinMPa(psi)

P=Perimeterofcutinmm(inches)

T=Thicknessofsheetinmm(inches)

C=8,896N/ton(2,000lb/ton)

Example

A3-mm(0.118-in.)thicksheetofEastmanSpectar™

copolyesterrequiresashearstrengthof56.5MPa

(8,195psi).Thepresstonnagerequiredtodiecutasheet

measuring381-mm(15-in.)squareiscalculatedinthe

followingequation.Theperimetermeasurementis

calculatedbymultiplying381mm(15in.)X4because

theshapeissquare.

F=(56.5MPa)(3mm)(1,524mm)=29ton

8,896N/ton

SI units

NOTE:Theactualcuttingforcerequiredtocutthroughathickersheetincreaseswithaddedsheetthickness.Shearstrength(psi)iscalculatedbydividingthecuttingforcebytheshearedarea.

F=(8,195psi)(60in.)(0.118in.)=29ton

2,000lb/ton

U.S. customary units

However,assheetthicknessincreases,theshearedarea

(sheetthicknessXcutlength/perimeter)overwhichthe

cuttingforceisdistributedincreasesatagreaterratethan

themagnitudeoftherequiredcuttingforce,thuscausing

theshearstrengthvaluestodecreasewithincreasing

thickness.

6

Page 9: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Die designDesignsfor2steel-rulecuttingedgesthatworkequally

wellwithsheetsupto2.5-mm(0.100-in.)thickareshown

below.Steelhardnessshouldbe45to55RockwellC,

dependingonthedegreeofbendingrequiredinfabrication.

0.030�

30°15°

10°

0.012� 0.045�

30°

30°

0.020�

Die cutting procedureAdjustthepresstomakeacompletecutinasinglestroke

withoutdamagingthedie.Shimthedieasnecessaryto

ensurethatallareascutuniformlythroughthesheetof

EastmanSpectar™copolyester.Toensurethattheentire

dieislevelandtrue

•TapeKraftorcarbonpaper,150-to200-mm

(0.006-to0.008-in.)thick,totheplate.

•Lowerdietomarkanimprintofthecuttingpattern.

•Shimlowruleareas.

•Makeatestcut.

•Alternatecutting/shimminguntilafull,uniformcutis

obtained.

•Positiontestpartsconsistently.

•Keepcuttingdiesassharpaspossible.

Topreventcontactbetweenthedieandthepressbed,use

asteelcuttingplate0.5-to3-mm(0.020-to0.118-in.)

thickwithaRockwellChardnessof30to35.

Bonding, fastening, and welding Bonding methodsSolventbondingisgenerallypreferredwhenthe

componentstobejoinedaremadefromsheetofEastman

Spectar™copolyester.However,adhesives,mechanical

fastening,orplasticweldingmaybeneededwhenjoining

dissimilarmaterialsorconsiderationssuchaspartsize,

bondflexibility,orbondappearanceprevail.Recommended

adhesivesincludecyanoacrylates,two-partacrylics,

two-partpolyurethanes,andtwo-partepoxies.

Solvent bondingTheexcellentchemicalresistanceofsheetofEastman

Spectar™copolyesterallowsitsuseincertainapplications

whereotherplasticmaterialsmightbeunsuitable.This

featuremustbetakenintoaccountwhenchoosinga

solventforanoptimumbond.Useofapropersolvent,

goodtechnique,andcuretimeshouldresultinaclear,

haze-freejointthatisstronganddurable.Whetherusing

thecapillaryactiontechniquecommonlyemployedfor

smallerpartsandbondsoffairlyshortlengthorsome

othermethod,thepartsmustfittogetherwellwithout

forcing—leaving no visible gaps. Forthebestbonding

results,allowthesolventtofullypenetratetheedgesto

bebonded.

Solvent selectionThereareseveraloptionsforbondingsheetofEastman

Spectar™copolyestertoitself.Theseincludecommercial

productsaswellascustomblendsofMEKandmethylene

chloride.Youmayalsoconsultthesheetextruderoryour

distributorforadditionalsolventagentssuitableforuse

withSpectarsheet.

7

Page 10: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

No gaps

Good

Shows gaps

Bad

Corner joint

Lap joint

MEK,afast-actingsolvent,givesquickersetupwithmore

likelihoodoffreeze-off(settingupbeforethejointisfilled).

Methylenechloride,ontheotherhand,isaslowersolvent

andoffersmoreworktimewithlesspotentialforfreeze-

off.Insomelocations,a50:50mixofmethylenechloride

andMEKisusedasastartingpointtoformulatecustom

solventblends.Asmallamountofaceticacidcanbeadded

whenbondinginhumidenvironments.

Somewater-thinformulasdesignedforbondingacrylics

canalsobeusedtobondsheetofEastmanSpectar™

copolyestertoitselfiftheyareusedwithcare.Weld-On™3

andWeld-On™4,availablefromIPSCorporation,aretwo

suchformulas.Hazingmay,however,occasionallybe

observed.

Donotusethickcementsintendedforusewithother

plastics;theyaregenerallyincompatiblewithSpectar

sheet.

•Useneedle-typeapplicator.

•Applysolventevenlyalongentirelength.

•Applyfrominsideforcornerjoints.

•Applyfrombothsidesforlapjoints.

Problem Possible cause Possible solution

Solventfreeze-off

UseofimpropersolventSwitchtoasystemdesignedforsheetofEastmanSpectar™copolyester.

Solventtooactive Dilutemixturewithaslowersolvent.

Applicationtechnique Reevaluatetechnique.

Hazy/cloudyjoints

Useoftoomuchsolvent Uselesssolvent.

Poorpartfit Improvepartfit.

Solventpooling Checklevelingofparttoreducepooling.

Oldsolventmixture Addfreshsolvent.

Weakjoints

UseofimpropersolventSwitchtoasystemdesignedforSpectarsheet.

Applicationtechnique Reevaluatetechnique.

Poorpartpreparation Preparepartproperly.

Voidsappearaspartcures

Useoftoomuchsolvent Uselesssolvent.

Poorpartfit Reshapepartstoimprovefit.

Solventpooling Checklevelingofpartsassolventisapplied.

PartshiftsduringsetupIncreaseclampingpressureand/oruseajigtoholdpartsinplacewhilebondsetsup.

Overlyroughsurface Lightlysandsurface.

8

Troubleshooting guide for solvent bonding

Page 11: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Adhesive bondingWhenjoiningdissimilarmaterials,solventbondsare

rarelystronganddurable,sotheuseofadhesivesisoften

recommendedforthispurpose.Theadhesiveselected

mustbecompatiblewitheachmaterialinvolved.

Ifthematerialsbeingjoinedexpandandcontractat

differentrates,aflexiblebondmayberequired.Takethis

intoaccountwhenselectingtheadhesiveformulation.If

expansionandcontractionareamajorconcern,consider

theuseofmechanicalfastening.

Adhesive characteristicsAvarietyofadhesivesareavailableforjoiningdissimilar

plasticmaterials.Asaresult,itisdifficulttomakegeneral

observations.Unlikesolvents,whichevaporate,an

adhesivelayerremainsafunctionalpartofthefinished

assembly.Hence,theperformanceandappearanceofthe

finishedpartmaydependprimarilyonthecharacteristics

oftheadhesivelayer.

Forexample,theselectionofabrittleadhesive,orone

thatcontainsaggressivechemicals,maylowertheimpact

strengthofsheetofEastmanSpectar™copolyester.Several

characteristicstoconsiderwhenselectinganadhesiveare

•Chemicalcompatibilitywiththepartsbeingjoined

•Aestheticsofthefinishedjoint

•Expansion/contractionwithtemperaturechanges

•Brittleness/rigidity/flexibility

•Weatherability,ifrequired

•Durability/servicelife

•Adhesivestrength(adhesiontotheplastic)

•Cohesivestrength(resistancetointernaltearing)

•End-userequirements

•Suitabilityforfoodcontact

Adhesive-bonding procedureJoinedsurfacesmustfitwellwithoutforcingandhaveno

visiblegaps.Thesurfacestobebondedshouldbesmooth

butnotpolished.Sandthesurfacestobejoinedwitha

120-gritorfinerpaper.Diamond-wheelpolishers,jointer/

planers,orothermechanicaldevicescanproduceexcellent

results.However,softpolishingwheelsorflamepolishing

arenotrecommendedasthesecanroundtheedges,

causinggapsandimproperfit.

Adhesive shrinkageSomeadhesiveswithavolatilecomponentmayshrink

whilecuring.Tocompensateforthis,cutthejointonan

angle,providingspaceforthejointtobeslightlyoverfilled.

Consultyouradhesivesuppliers’literatureforspecific

informationonshrinkage.

Angle to provide space for the joint to be slightly overfilled to compensate for shrinkage.

Overfill to allow for shrinkage.

9

Page 12: Fabricating and forming sheet - · PDF fileFabricating and forming sheet ... These include circular saws, band saws, saber saws, jigsaws, hacksaws, or handsaws. However, circular saws

Tips on adhesive bonding•UseanadhesivesystemtobondsheetofEastman

Spectar™copolyestertoothermaterialssuchasacrylic

orpolycarbonate.

–ForbondingsheetmadewithSpectartoitself,use

Weld-On™58,Weld-On™55,Weld-On™42,

Scotch-Weld™DP-100,Durabond™105CL,LightCure

3104,LightCure3105,UltraLight-Weld™3072,or

PlasticWelderII.

–ForbondingsheetofSpectartosheetofacrylic,use

Weld-On™42,Durabond™105CL,LightCure3104,Light

Cure3105,UltraLight-Weld™3094,UltraLight-Weld™

3072,orPlasticWelderII.

–ForbondingSpectarsheettopolycarbonatesheet,use

Weld-On™58,Weld-On™55,Durabond™105CL,Light

Cure3104,LightCure3105,UltraLight-Weld™3094,

UltraLight-Weld™3072,orPlasticWelderII.

•Usethefollowingprocedure

–Startwithaflatsurface.

–Preparethesheetproperly

•Removeallforeignparticles.

•Wipesurfacewitha50:50mixtureofisopropyl

alcoholandwater.

•Allowsurfacestodrythoroughlybeforebonding.

•Sandingwithfine-gritsandpapertolightlyroughen

thesurfacestobebondedmayimprovebond

strength.

-Applythetwo-componentsystemtoonesurface.

-Placethetwosurfacesindesiredbondedposition.

-Filljointscompletelywithadhesivesothatnovoids

remain.

-Useajigorfixturetosecurelyholdpartsbeing

bondedtogetherwhilecuring.

-Followmanufacturer’srecommendationsforproper

pressureandtimeneededfortheadhesivetocure.

-Alwaysuseproperventilation.

Mechanical fasteningBecauseofitsoutstandingtoughness,sheetofEastman

Spectar™copolyesteradaptstomechanicalfasteningmore

readilythansomeothermaterials.Thismethodisuseful

whenassemblingorinstallinglargeorheavyparts,or

whenasuitablesolventoradhesivesystemisnotavailable.

Usescrewsdesignedspecificallyforplastics.Ifbolting

partstogether,allowforthermalexpansionand

contractionbydrillingoversizedholes.Makesurethe

holeshavesmoothedges.Useofwashersissuggested

whenboltingforbetterloaddistribution.

Usemetalinsertsiffrequentassembly/reassemblyis

involved.Insertsarenotrecommendedwherethermal

expansionandcontractionmayoccur.

Donotoverlytightenscrewsoruseself-tappingscrews.

Plastic weldingAlwayspredrilltheopeningfortherivetlargeenoughto

allowforexpansionandcontractionoftheplasticsheet.

Useofmetalrivetsisnotrecommendedwhenmechanically

fasteninganyplasticsheet,butifitisnecessarytouse

metalrivetstofastenEastmanSpectar™copolyester,use

rivetsthatarespecificallydesignedforplastics.They

shouldhavelargefasteningheadstodistributethestress

loadonthe“rivethead”side.Also,theuseofawasher

onthe“nonrivethead”sideisrequiredtodistributethe

stressloadthatwillbeinducedwhenusingtightening

metalrivets.Whenusingplasticrivets,alsoallowfor

expansionandcontractionofthesheet.Plasticrivetsare

recommended.

Technologyhasbeendevelopedthatallowsplasticsheet

fabricatorstoobtainclear,strongbondsbyweldingwitha

rodofSpectarsheetmaterial.Thetechnologycanbeused

tobondSpectarsheettoitselfortootherplasticsheet

materials.

Likemetalwelding,particularlywire-feedwelding,plastic

extrusionweldingproducesastrong,uniformbondon

plasticsheetorotherplasticapplications.

10

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Therearemanyadvantagesofplasticweldingthatcan

beeasilyrealizedwhenworkingwithSpectarsheet.

Advantagesinclude

•Nomessyorenvironmentallyunsafegluesorsolvents

•Clear,yettoughbonds

•Quickfabrication—nodryingtimerequired

•Watertight,long-lastingjoints

•Diversefasteningmethodforavarietyofapplications

•Better,strongerdesigns

•Suppliersofcopolyesterrods

–K-MacPlastics

3821ClayAvenue,SW

Wyoming,MI49548

Tel:(616)406-0671

www.k-mac-plastics.com

–NewImagePlastics

2411S.LocustStreet

CanalFulton,OH44614

Tel:(330)854-3010

www.plasticweldingrod.com

Tips for bondingThebondingrecommendationsoutlinedherearebasedon

experienceworkingwithEastmanSpectar™copolyesterin

Eastman’sTechnicalServicelaboratoriesinKingsport,

Tennessee.Theycanbeusedasastartingpointoras

guidelinesindeterminingoptimumbondingconditions.

•Startwithaclean,flatsurface.

•Preparethesheetproperly.Removeallforeign

particles.

–Wipesurfacewitha50:50mixtureofisopropyl

alcoholandwater.

–Allowtodrythoroughlybeforebonding.

Bonding sheet of Spectar™ copolyester to itself•Useanappropriatesolventoradhesive.

–Usesolventssuchasmethylenechloride,

cyclohexanone,tetrahydrofuran,Weld-On™3,

Weld-On™4,CasewaySC125,MC-Bond,oratwo-

componentadhesivesuchasWeld-On™58.

Using solvents•Besurethatsurfacestobebondedaresmoothandmate

well.Edgebondsshouldbefinishedusingajointeror

router.

•Applysolventtothejointedgewithahollowneedle.

Solventwillwickintothejointbycapillaryaction.

•Useminimumamountofsolventtowetsurfacesto

bebonded.

•Useajigtoholdpartsinplacepriortobonding.

•Greentimeistypically60–90sec.

Using a two-component adhesive system•Applythetwo-componentsystemtoonesurface.

•Uselightpressuretoholdthesurfacesbeing

bondedtogether.

•Followmanufacturers’instructionsfordetails.

Bonding sheet of Spectar™ copolyester to other materials such as acrylic or polycarbonate•Useanadhesivesystemratherthanasolvent-based

system.

•UseWeld-On™58orWeld-On™42.

•Whenusingadhesives,sandingwithfine-gritsandpaper

tolightlyroughenthesurfacestobebondedmay

improvebondstrength.

•Applythetwo-componentsystemtoonesurface.

•Followmanufacturers’recommendationsfortheproper

pressureandtimeneededfortheadhesivetocure.

•Eastmanhasfoundthaturethane-basedadhesives

workbest.

•Donotusetoomuchsolventorallowsolventtopoolon

theplastic.

•Donotusemethylethylketone,cyclohexanone,orTHF

foredgebonds.

11

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Problem Possible cause Possible remedies

Poorbondappearance

VoidsduetoroughsurfacesNeedsmootheredges.Startwithjointededges.Addrouteredge.

Whiteningduetosolventinducedcrystallization

Minimizeamountofsolventused(avoidsolventpooling).Tryusing“dip”method.Switchtoadhesives.

Whitening/bubblesduetohighhumidity

Fabricateinanareawithlowrelativehumidity.Usesolventswithaslowerevaporationrate.

PartsmovedbeforebondsetsUseajig,clamp,orfixturetoholdthepartsfixeduntilthebondhassetup.

Solventbondstrength

Wrongsolvents Userecommendedsolvent.

ExcessivesurfaceroughnessStartwithajointed/routededge.Ifnecessary,addmethylenechloridetosolventmixturetohelpdissolveroughness.

AAMManufacturingInc.1755HubbardDriveBatavia,IL60510Tel: (800)272-0595Fax:(630)406-9622

IPSCorporation455W.VictoriaStreetCompton,CA90220Tel:(310)898-3300

Polysciences,Inc.400ValleyRoadWarrington,PA18976Tel:(800)523-2575

For additional information on the adhesives and solvents discussed, contact

FormingForming methodsSheetofEastmanSpectar™copolyesterisuniquelysuited

toavarietyofformingoperations,offeringacombination

offeaturesunmatchedbyacrylicorpolycarbonate.The

sheetcanbeformedwithoutpredrying,formsatlower

temperatures,heatsandcoolsrapidly,releaseseasilyfrom

themold,andprocesseswithimpressiveconsistency,all

translatingintomajorlabor,energy,andcapitalsavings.

Deepdrawsandintricatepartdefinitionareroutine,using

simplevacuumpressure.Themostcommonthermoforming

techniquesincludelinebending,freeforming,and

vacuumforming.

Thermoforming ovenSheetofEastmanSpectar™copolyestermaybeheated

usingsingle-ordouble-sidedradiantheatorconvection

ovens.Whilesingle-sideheatingiscommon,itcanheat

thesheetunevenly.However,Spectarsheetwillformwell

usingone-sidedheatatgauges≤0.177mil.Formorecritical

applicationssuchasdistortionscreen-printing,complex

shapes,orverydeepdraws,usedouble-sidedradiantheat

withzonecontrolifpossible.

Vacuum formingLinebendingandfreeforminglimitthevarietyofshapes

thatcanbeproducedfromsheetofEastmanSpectar™

copolyester.Thereis,however,virtuallynolimittothe

varietyofshapesthatcanbeachievedthroughvacuum

forming.Inthisprocess,heatthesheetandthenposition

overamaleorfemalemold.Evacuatetheairbetweenthe

sheetandthemoldsurface.Holdthevacuumwhilethe

partcools,thenreleasethevacuumandremovethepart

fromthemold.Positivepressure,oracombinationof

positiveandnegativepressure,canbeused.Spectarsheet

canbethermoformedonvirtuallyanyhorizontal

thermoformingequipment.

12

Troubleshooting guide for bonding sheet of Eastman Spectar™ copolyester

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Free formingFreeformingisagoodtechniquetoproducedomes,

bubbles,andothersymmetricalshapes.Achievingsome

shapesmaybeassimpleasallowingthesheettosaginthe

oven,withoutpressure,toadesireddepth,atwhichpoint

thepartisremovedtocool.Heatthesheet,thenseal

againsttheopeningofapressureboxandapplyair

pressuretoforcethesheetintothedesiredshape.Hold

pressureconstantwhilethepartcools.Theshapeofthe

openingandthequantityofairforcedintothebox

determinetheshape.Ineithercase,theformedpart

exhibitsanexcellentfinishbecausetheheatedsheet

nevermakescontactwithamoldsurface.Anotheroption

involvesusingavacuumboxthatgivessimilarresults.

Air inAir out

Hold pressure constantwhile the part cools.

Line bendingTolinebend,heatthesheetononesideto100°to120°C

(212°to250°F)alongastraightline.Bendtothedesired

angleandholdinplaceuntiltheparthascooledandthe

newshapeisset.Ajigisusefulforholdingthepartinplace

duringcooling,althoughitmaybepossibletoholdthepart

inthedesiredpositionbyhand.

Cold bendingColdbendingcanbeusedtoproducesimpleshapes

fromsheetofEastmanSpectar™copolyester.When

brakeforming,themaximumamountofbendwilldepend

onsheetthicknessandrateofdeflection.Coldbending

sheetmorethan2.5-mm(0.100-in.)thickwilllikelycause

highstresslevels,whichmayleadtopartfailure.When

coldbending,usethegeneralrecommendationof

radiusequals100Xthicknessofsheet.

Forming temperatureSheetofEastmanSpectar™copolyesterwillformatlower

temperaturesandoverawiderrangeoftemperaturesthan

acrylicorpolycarbonate.Typicaloventemperaturesof

200°to260°C(400°to500°F)producecorresponding

sheettemperaturesof135°to155°C(275°to310°F),

measuredfromthetopofthesheet(intopheatonly

oven).Toomuchheatcanresultinexcessivesag,which

mayleadtowebbingorbridgingwhenvacuumisapplied.

Monitorsheettemperatureswithaninfraredthermometer

orobservethedegreeofsag.Ifthesheethasbeenstored

forlongperiodsunderconditionsofhighhumidity,selecta

formingtemperatureonthelowerendoftherange.

Ageneralguidetoformingtemperaturefollows.

Factor Temperature range

Deepdraws Higherend

Moderatedraws Lowerend

Largeparts Lowerend

Highmoisture Lowerend

Complexdetail Higherend

Part removalReducethepossibilityofwarpingbyallowingformedparts

tocoolto50°C(120°F)orlowerbeforeremovingthem

fromthemold.Theywillcontinuetocoolafterremoval,

sopropersupportisrequiredtopreventdeformation.This

isespeciallytrueforlarge,heavyparts.Topreventdishing

(concaveshape),largepartsshouldbesupportedalong

theiredges,facedown,untilcompletelycooled.Donot

nestformedpartssincethiscancauseblockingand

scratching.Largepartsshouldbefullysupportedwhen

beingtransportedtopreventexcessiveflexing.

13

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MoldsMold materials

Commonlyusedmoldmaterialsincludewood,vacuum

board(mediumdensityfiberboard),pressurelaminates

(forflatsurfaces),plasters,aluminum-filledepoxies,

automobilebodyputties,fiberglass,andaluminum.Molds

madefromwoodorvacuumboardareinexpensiveand

easytofabricateintothedesiredshapewithcommon

woodworkingtools.Limitationsofwoodenmoldsinclude

durability,slowerpartcooling,andlesscontrolover

surfacetexture.

Mold finish

FormedsheetofEastmanSpectar™copolyesterprovides

anexcellentreproductionofthemoldsurface.Forthis

reason,vacuumholesshouldbenomorethan0.4mm

(0.015in.)indiameter.Keepthemoldsurfacecleanduring

formingoperation(evendustmarkscanbepickedupinthe

surfaceoftheformedpart).Asmooth,cleanmoldsurface

producesasmooth,cleanformedpart.Ontheotherhand,

usinguniquemoldfinishesoffersawiderangeof

customizeddesignpossibilities.

Mold design

FormedsheetofEastmanSpectar™copolyestertypically

hasverygoodreleasecharacteristics.Formostmalemolds,

aminimumdraftangleof5to7degreesensureseasypart

removal.Large-scaleproductionrunsmayjustifythe

productionofaprototypemoldtodetermineoptimum

draftangles,shrinkage,andothermolddesignfeatures.

PartsformedfromSpectarsheetwilltypicallyshrink

about0.5%.

Sharpedgesandcornersonmoldsshouldbeavoided.A

minimuminternalcornerradiusequaltotheinitialsheet

thicknessisrequired.AlthoughformedsheetofSpectar

typicallyhasverygoodreleasecharacteristics,the

complexityofthemoldhasasignificanteffect.

Thickness control

Thewallthicknessofvacuum-formedpartsvarieswith

thinnerareasoccurringatthepointsofdeepestdrawor

greateststretch.Forexample,ifapanconfigurationis

drawnintoafemalemold,thethinnerareaswilloccur

atthecorners,orface,oftheformedpart.Material

distributioncanbeoptimizedthroughmolddesign,the

useofplugassist,orbillowing,dependingonthespecific

designofthepart.

Predecorated sheetSinceitformsatlowertemperatures,sheetofEastman

Spectar™copolyestermaybeusedwithlessconcernabout

overheatingpreappliedinksorvinylfilms.Insomecases,

partshavebeenformedwiththedecoratedsurfacein

contactwiththemoldwithnoadverseeffects.The

compatibilityofSpectarsheetwithvinylcanallowthicker

gaugesheettobeusedthanwithpolycarbonatewithout

thefearofdamagingthevinyl.Thesefactorsmake

predecorationandsubsequentformingasnap!Another

factorinpredecoratingSpectarsheetisitsevenmaterial

distributionduringtheformingprocess,leavinglesschance

forink,paint,orvinylthinning.

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Problem Possible cause Possible solution

Webbingorbridging

Sheettoohot Decreaseheatingtimeortemperature.

ComplexshapeUsefemalemoldand/orprestretchsheetwithplugorpressureassist.

Bubblesinformedsheet Sheettoohot Reduceformingtemperature.

Surfacedefectsonpart

Oversizedvacuumholes Usesmallerholes.

RoughmoldsurfaceSand/polishmold.

Usealuminummold.

Dirtymold Cleanmold.

Releasedifficulties Insufficientdraft Increasedraftangleorusefemalemold.

PoormaterialdistributionFormingtechnique Tryplug,bubble,orvacuumassist.

Unevenheat Adjustheatzones.

Unevensag Unevenheat Adjustheatzones.

Poordetail

Vacuumreleasedtoosoon Holdvacuumlonger.

Vacuumappliedtooslowly Applyvacuumsooner.

Sheettoocold Increaseheatingtimeortemperature.

Warpedparts Insufficientcooling Allowpartstocoollongerinmold.

Tips for thermoformingEastman’sthermoformingrecommendationsarebasedon

experienceworkingwithsheetofEastmanSpectar™copolyester

initsTechnicalServicelaboratoriesinKingsport,Tennessee.

Theycanbeusedasastartingpointorasguidelinesin

determiningoptimumsheetthermoformingconditions.

•Useaminimumdraftangleof5°inmalemoldsforeasy

partrelease.

•Keepmoldsveryclean.Removedustwithadampclothand

blowitoffwithpressurizedair.

•Useloweroventemperatures(200°–250°C[400°–480°F])

thanusedforacrylicandpolycarbonate.

•Usealowermoldtemperaturethanusedforacrylicor

polycarbonate.Forlong-termproduction,atemperature-

controlledmoldisrecommendedbutnotrequired.

•Heatthesheetto135°–155°C(275°–310°F).The

optimumis150°C(300°F)usingatopheaterovenand

measuredfromtopofsheet.Applyheatonthesidethat

willbeoutsidethebend.

–Highertemperaturesfordeep-drawnpartsand

highdetail

–Lowertemperaturesforlargepartsandshallowdraws

•Useamountofsagasasheet-heatingcontrol.

•Useavacuumof508mm(20in.)Hgorgreater.

•Removethepartatlowertemperatures(50°C[<120°F])

topreventpartwarpage.Whenusingamalemold,the

partshouldberemovedassoonaspossibleandthen

placedbackontothemold.Thishelpspreventthepart

fromstickingtothemoldandhelpspreventpartwarpage

asitcontinuestocool.

•Forhighlydetailedmolds,alightdustingwithtalcum

powderhelpstheparttoreleasemoreeasilyandwill

extendthelifeofthemoldaswell.

•Alwaysallowgenerousradiioninternalcorners(≥initial

sheetthickness).

•Donotdrythesheetbeforethermoforming—not

necessary.

•Donotusetoocoldamold(25°C[<60°F])toprevent

nonuniformstretchingandpartwarpage.

•Donotusetoohotamold(60°C[>122°F])toprevent

warpingorsticking.

•Donotoverheatthesheet(165°C[>330°F])toprevent

excessivesagging.

15

Troubleshooting guide for thermoforming sheet of Eastman Spectar™ copolyester

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DecoratingThereareliterallyhundredsofcommerciallyavailableinks

andpaintsthatcanbeusedtodecoratesheetextruded

fromEastmanSpectar™copolyester.Whenchoosinginkor

paint,considerationshouldbegiventothefitness-for-use

requirementsofdecoratedparts.Forexample,willthe

decoratedpartbesubjectedtoconsumerabuseorwillit

encounterlittleornoabuse,suchasadecoratedsign.The

followinginformationofferssomegeneralguidance

regardingthedecorationofSpectarsheet.

General informationWhetheryouwanttoscreen-print,spraypaint,oruseany

othermethodtodecorateafabricatedsheetofEastman

Spectar™copolyester,thecorrectinkorpaintformulation

mustbechosenthatallowsthefullydecoratedpartto

meetitsintendedfitness-for-userequirements.Sheet

extrudedfromSpectarinherentlyexhibitsexcellent

chemicalresistance.Goodchemicalresistanceisgenerally

consideredadesiredcharacteristic;however,itisalsoone

ofthereasonsthatinkorpaintadhesiontothesurfacecan

sometimesbemarginal.Theproperchoiceofsolvent,in

combinationwiththeresinbackboneoftheinkorpaint,is

animportantconcernandshouldbeevaluatedbytheink

manufacturerusingtheScotch™tapeadhesionmethod.

Anotherinherentpropertyofthesheetisitstoughness.

Thispropertycanbecompromisedbyimproperly

decoratingthesheet.Thewrongsolventsystemand/ora

rigidfilm-forminginkorpaintsystemcannegatively

affectthetoughnessofthedecoratedpart.

Followingtheserecommendations,alertingyourink

suppliertotheseconcerns,andknowingthefitness-for-use

requirementsofthefullydecoratedpartwillminimize

theseconcerns.

CleaningBeforeanypieceofplasticcanbedecorated,itneedstobe

cleanedandstaticbuildupremoved.Thisiseasilydoneto

sheetofEastmanSpectar™copolyesterusinga50:50

mixtureofisopropylalcoholandwater.Aswithpaintsor

inks,therearemanycommercialsolutionsthatcanbeused

tocleanandremovestaticfromplasticsheet.Itshould

notbeassumedthatthesesolutionscanbeusedon

Spectarsheet.Eastmanencouragestheuseofthese

mixturesONLYaftertestinginaninconspicuousarea.

Applythecommercialmixtureaccordingtothe

manufacturer’sinstructionsandinspecttheareafor

visualcrazingand/orhazingofthesheetsurface.

Printing inks and substratesThermoplasticsubstratesareimpervious,ornonporous,

andnormallyrequirespecificinkformulationsforquicker

dryingandbetteradhesion.Solvent-andwater-basedinks,

aswellasultravioletandelectron-beamcurableinks,are

availableformostplasticprintingprocesses.Enamel,

epoxy,acrylic,polyester,andpolyurethane-basedinks

arecommonlyusedforpolymers.

Surface tensionsForbetterwetting,thesurfacetensionsoftheinks

shouldbelowerthanthatoftheplasticsbeingprinted.

Water-basedinkstypicallyhavehighersurfacetensions

thansolvent-basedinks.Water-basedinkscanbeadjusted

withalcoholtolowertheirsurfacetensionforimproved

wettingandadhesion.Workwithexperiencedink

suppliers—itiseasiertoadjusttheinkthanthesubstrate.

CoronasurfacetreatmentscanbeappliedtoEastman

Spectar™copolyester.Thetreatmentincreasessurface

tensionandsurfacepolarityresultinginimproved

adhesion.

Static controlStaticcontrolisanimportantissuewhenprintingon

thermoplasticsubstrates.Excessstaticmaycauseblocking

insheetfedoperations.Inconsistentinklaydownininkjet,

laser,andsimilarprintingtechniquesmayalsobe

attributedtostaticcharge.Groundingtheequipment

andsubstrate,usingstaticeliminatorbars,andforced

deionizedairblownontothesubstratehaveprovento

alleviatetheseproblems.

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Choosing inks or paintsBeforechoosinganink/painting/decorationtechnique,

theend-userequirementsneedtobewellunderstood

andconveyedtotheprinter,inkmanufacturer,paint

formulator,etc.Manycommerciallyavailableinksand

paintscanbeusedtodecoratesheetofEastmanSpectar™

copolyester.Thesolventschosentoformulatemostinksor

paintsdonotdecreasethephysicalpropertiesofthesheet.

Generally,thechosenresinintheinkorpaintformulation

willcompromisethephysicalpropertiesofthesheettoa

greaterextentthanthesolventsintheformulation.There

arealwaysadhesionconcernswithanyinkorpaintafter

thecoatingisappliedtoaplasticsubstrate.Itisextremely

importantthatadhesionbetestedafterthechosenink

orpainthasbeenappliedAND is fully cured!Eastman

recommendstestingforadhesionafterthesamplescan

bephysicallyhandledandhavebeencuredinanovenfor

48hoursat50°C.UsuallytheScotch™tapeadhesiontestis

performed(ASTMD3359-B).Thisisdonebyetchinga

“checkerboard”patternonthedecoratedsheetand

attemptingtoremovethepaintorinkintheetchedarea

withtape.ThetestcallsforScotch™610tapetobeused

andabrisk,steadypullshouldbeperformed.Thedriedink

orpaintfilmshouldbehardtoremovebythismethod.

WorkatEastmanhasshownthatthe“flexibility”ofthe

driedfilm,whetheritisinkorpaint,isanimportant

characteristicforadhesionandretentionofsheettoughness.

Driedinkorpaintfilmsthatremainflexibleathighandlow

temperaturesseemtoadherebettertothesheetandhelp

maintainsheettoughnessbetterthan“rigid”film-forming

inkorpaintsystems.Thisisonlyimportantifthefitness-

for-userequirementsofthedecoratedsheetrequirethe

decoratedparttobesubjectedtoabuseorroughhandling.

Arigidfilm-forminginksystem,whenappliedtoSpectar

sheet,shouldbeexpectedtobehaveinamorebrittle

mannerthanaflexiblefilm-forminginksystem.Ifthefully

decoratedfitness-for-usesheetofEastmanSpectar™

copolyesterisapoint-of-purchasedisplaywhereimpact

isn’tamajorconcern,mostanyinkwillmeettheneedsof

thisapplication.Inthiscase,adhesiontoSpectarsheetwill

betheonlyconsideration.

Testing ink or paint•Coatorprintsamplesofthechoseninkorpaintonsheet

ofEastmanSpectar™copolyester.(Includeafloodcoat

ifnecessary.)

•Cureordrythepreparedsamplespertheink

manufacturer’srecommendations.

•Checkadhesion(ASTMD3359-B)beforeandafteraging

inanovenat50°C(122°F)for48hours.

•Checktheimpactofagedsamplesatroomtemperature

and210°C(410°F)usingASTMD3763.

Spray paintingConventionalspray-paintingtechniquesareoftenusedto

decoratelargepanels.Therearecommercialspraypaints

availableforsheetofEastmanSpectar™copolyester.

Whenselectingpaint,carefullyconsiderfitness-for-use

requirementssuchasdryfilmadhesionandimpact

strengthretention.Obtainmoredetailedinformation

aboutthesecharacteristicsfromthepaintsupplier.

Dry film adhesionSheetofEastmanSpectar™copolyestergenerallyexhibits

excellentchemicalresistancecomparedwithotherplastic

sheetmaterials.Asaresult,somesolvent-basedpaints

designedforusewithpolycarbonateoracrylicmaynotbe

sufficientlyactivetoprovidegoodadhesiontoSpectar

sheet.Generally,paintthatproducesaflexible,toughdry

film,suchassomepolyurethanes,hasbetteradhesionthan

oneyieldingarigid,brittlefilm.Contactyourpaintsupplier

fordetails.

Impact strengthTheexcellentimpactstrengthofsheetofEastman

Spectar™copolyesteraccountsforitsuseinahostof

demandingapplications.Itisimportantthatsuch

fitness-for-userequirementsbeclearlycommunicatedto

thepaintsupplier.Contactyourinkorpaintsuppliersfor

recommendationsonwhattousewithPETG.

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Spray maskingConventionalspray-maskingmaterialsworkwellwith

sheetofEastmanSpectar™copolyester.Comparedwith

acrylicorpolycarbonate,itmaybeeasiertocutawaythe

maskingsincepartsformedfromSpectarsheetusually

exhibitcrisperformingdetailtoguidetheknife.When

cuttingthemasking,useasharpknifeandminimum

pressuretoavoidcuttingintotheplasticsheet,asthis

maynotchthesheet,reducingitsimpactresistance.

PrintingManyprintingprocessescanbeusedwithsheetof

EastmanSpectar™copolyester.Theprocessdepends

largelyontheconfiguration,productionvolume,and

fitness-for-userequirementsofthefinishedpart.Specially

formulatedinksareavailabletomeetthespecific

requirementsforagivenenduse.Consultyourinksupplier

todeterminethebestchoiceofinksandapplication

techniques.

Hot stampingCopy,trademarks,andotherdesignelementsmaybe

transferredtoflat,smoothsurfacesonsheetofEastman

Spectar™copolyesterbyhotstamping.Eastmanhasfound

dietemperaturesof149°to204°C(300°to400°F)anda

1to2seconddwelltimeat0.62MPa(90psi)agood

startingplace.Additionalinformationonhotstamping

canbeobtainedfromfoilmanufacturers.

Vinyl decoratingBenefitsofvinyldecoratingsheetofEastmanSpectar™

copolyesterincludeuniformcolordistributionandcorrect

colormatches.Also,vinylcanbeappliedtofirstand

secondsurfacespriortoforming.

Summary of fabricating and forming Eastman’srecommendationsarebasedonexperience

workingwithsheetofEastmanSpectar™copolyester.

Sheet storage and handling•Storesheetatroomtemperatureinadryarea,not

directlyexposedtosunlightorheat.

•Makecertainthemaskingfilmisnotremovedpriorto

use,asnormaldustanddirtwillbeattractedtothe

sheetbecauseofstaticelectricity.Themaskingwill

alsopreventscuffingandscratching.

•Topreventwarpage,thesheetshouldideallybestored

flat,asdelivered.Ifverticalstorageisnecessary,itisbest

tostoreataslightanglewithsupportunderneath.

Fabricating•Mosttoolssuitedforplasticsarebest,buttoolsfor

woodormetalmaybeused.

•Cold bending—Coldbrakebendingcanbeusedto

producesimpleshapes.Themostattractivebendsare

obtainedwith thicknesses less than 3.0 mm (l in.).The

radiusofcoldbendsshouldbenolessthan100times

theinitialsheetthickness.

•Hot bending—Anelectricstripheaterwithoptimum

sheettemperatureof107°C(225°F)maybeused.

•Sawing—Circular,bandandsabersaws,jigsaws,and

handsawsaresuitable.Triple-chipbladesofferthebest

performanceforcircularsaws.

•Drilling—Drillbitsdesignedforplasticsaresuggested.

•Shearing—Canbecutusingasheetmetalshearwith

sharpblades.Typically,shearcuttinglessthan16.5-mm

(l-in.)gaugeyieldsthebestvisualresults.Qualityof

theshearededgedependsontheshearingmachine’s

tolerances,cuttingcapacity,andblade“rake”angle.

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Apply heat gradually using a gentle sweeping motion.

•Punching—Canbepunchcutwithbestvisualresults

at gauges less than l in. (3.0 mm).Qualitydependson

thepunchingmachine’stolerances,cuttingcapacity,and

blade“rake”angle.

•Routing—Toobtainthebestroutingresults,usetwo-

flutetwistedcutters.

•Common heat guncanbeusedtoeliminatescratches.

Caremustbetakentoavoidwarping.Practiceon

noncriticalareasfirst.Lightsurfacescratchescaneasily

beremovedfromsheetofEastmanSpectar™copolyester

byapplyingheatfromahand-heldtorch(typicallybutane

oroxygen/hydrogen)oranelectricheatgun.Toremove

shallowscratches,itisbesttoapplyheatevenlywith

severalpasseslengthwiseoverthescratch.Toavoid

overheatingordamagingthesheet,careshouldbetaken

tonotfocustheheatinaconstantposition.Thoughthis

techniqueworksforlightsurfacescratches,deep

scratchesorgougesinthematerial’ssurfacearenot

suitableforrepairbythismethod.

•SheetofEastmanSpectar™copolyestermaybe

–Mechanical polished—Edgefinishingusing

mechanicalpolishers1isbestdonebystartingwithas

flatanedgeaspossible(suchasfromjointingorrouting

aftersawing—sawededgesaredifficulttofinish

becauseoftheroughness)andthenusingfairlylight

pressureonthepartandaconstantfeedrateacross

thepolishingsurface.

–Flame polished—Forbestresults,usea cooler

flame (butane or propane)afterthesawededgehas

beendeburred,jointed,routed,and/ordiamondedge

polished.Polishingisbestwhenusingauniformrateof

movementandisverytechniquedependent.Flame

treatmentcanembrittlethesheetedge.

–Solvent polished—Usemethylethylketone(MEK)or

methylenechloride.Avoidspilloverandpoortechnique.

ThisismoredifficultwithsheetofEastmanSpectar™

copolyesterthanwithacrylicsheet.

–Hot stamping and heat transfer printingaregood

decoratingmethods.Variousfoilsandtransferdecals

havebeenusedsuccessfully.

Thermoforming•No need to drythesheetbeforethermoforming.

•Readilyformablebyconventionaltechniques,including

traditionalvacuumforming,bending(coldorhot),anda

varietyofplug-assist,pressure,bubble,andsnap-back

methods.

–Uselower oven temperatures 200°–260°C

(400°–500°F)thanusedforPMMAandPC.

–Uselower mold temperatures <50°C(<120°F)than

usedforPMMAandPC.

–Sheettemperaturesof135°–155°C(275°–310°F)are

recommendedwithanoptimumtemperaturebeing

150°C(300°F).

–Useplug-assistmethodsfordeep-drawmolds.

•Useamoderatedraftangle(>3°–5°)onmoldstoaid

releaseofthefinalpart.

–Removethepartatlowertemperatures(lessthan65°C

[150°F])topreventpartwarpage.

Bonding•Solvent—Forsolventbondsthatareclear,long-lasting,

strong,tough,andbubble-free,usecommercialproducts

suchasCasewaySC125,MC-Bond,andWeld-On™3

and4.

•Don’t usetheregularsolventsystemsdesignedfor

polycarbonateoracrylic.

• Adhesives—Startwithaflatsurface.Foradhesive

bonding,preparethesheetproperly

–Lightlysandwithfine-gritsandpapertoimprove

adhesion.

–Wipethesurfacewitha50:50mixtureofisopropyl

alcoholandwater.

–Allowtodrythoroughlybeforebonding.

–SuggestedadhesivesincludeWeld-On™40,

Weld-On™42,andWeld-On™58.

1Diamond polishers are available from Mutronic (Tel: [0049] 8362/930900) or Edge Finisher Corp. (Tel: [1] 203-796-7923).

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Decorating sheet of Eastman Spectar™ copolyester•Spray painting—Whenselectingpaint,carefullyconsider

fitness-for-userequirementssuchasdryfilmadhesion

andimpactstrengthretention.Obtainmoredetailed

informationaboutthesecharacteristicsfromthepaint

supplier.

• Dry film adhesion—Avoidsolvent-basedpaints

designedforusewithpolycarbonateoracrylic.Generally,

apaintthatproducesaflexible,tough,dryfilmhasbetter

adhesionthanoneyieldingrigid,brittlefilm.Contactyour

paintsupplierfordetails.

• Spray masking—Conventionalspray-maskingmaterials

workwellwithsheetofEastmanSpectar™copolyester.

Whencuttingthemasking,useasharpknifeand

minimumpressuretoavoidcuttingintotheplastic

sheet,asthismaynotchthesheet,reducingitsimpact

resistance.

• Printing—Manyprintingprocessescanbeusedwith

sheetofEastmanSpectar™copolyester.Theprocess

dependslargelyontheconfiguration,productionvolume,

andfitness-for-userequirementsofthefinishedpart.

Speciallyformulatedinksareavailabletomeetthe

specificrequirementsforagivenenduse.Consultyour

inksuppliertodeterminethebestchoiceofinksand

applicationtechniques.

• Vinyl decorating—Benefitsofvinyldecoratingsheet

ofEastmanSpectar™copolyesterincludeuniformcolor

distributionandcorrectcolormatches.Also,vinylcanbe

appliedtothefirstandsecondsurfacespriortoforming.

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Eastman Chemical CompanyCorporate HeadquartersP.O. Box 431Kingsport, TN 37662-5280 U.S.A.

Telephone:U.S.A. and Canada, 800-EASTMAN (800-327-8626)Other Locations, (1) 423-229-2000Fax: (1) 423-229-1193

Eastman Chemical Latin America9155 South Dadeland Blvd.Suite 1116Miami, FL 33156 U.S.A.

Telephone: (1) 305-671-2800Fax: (1) 305-671-2805

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Telephone: (31) 10 2402 111Fax: (31) 10 2402 100

Eastman (Shanghai) Chemical Commercial Company, Ltd. Jingan Branch1206, CITIC SquareNo. 1168 Nanjing Road (W)Shanghai 200041, P.R. China

Telephone: (86) 21 6120-8700Fax: (86) 21 5213-5255

Eastman Chemical Japan Ltd.MetLife Aoyama Building 5F2-11-16 Minami AoyamaMinato-ku, Tokyo 107-0062 Japan

Telephone: (81) 3-3475-9510Fax: (81) 3-3475-9515

Eastman Chemical Asia Pacific Pte. Ltd.#05-04 Winsland House3 Killiney RoadSingapore 239519

Telephone: (65) 6831-3100Fax: (65) 6732-4930

www.eastman.com

Material Safety Data Sheets providing safety precautions

that should be observed when handling and storing Eastman

products are available online or by request. You should obtain

and review the available material safety information before

handling any of these products. If any materials mentioned

are not Eastman products, appropriate industrial hygiene and

other safety precautions recommended by their manufacturers

should be observed.

Neither Eastman Chemical Company nor its marketing affiliates

shall be responsible for the use of this information or of any

product, method, or apparatus mentioned, and you must make

your own determination of its suitability and completeness for

your own use, for the protection of the environment, and for the

health and safety of your employees and purchasers of your

products. NO WARRANTY IS MADE OF THE MERCHANTABILITY

OR FITNESS OF ANY PRODUCT, AND NOTHING HEREIN WAIVES

ANY OF THE SELLER’S CONDITIONS OF SALE.

Eastman and Spectar are trademarks of

Eastman Chemical Company.

All other brands are the property of their respective owners.

© Eastman Chemical Company, 2011.

TRS-236A 5/11Printed in U.S.A.