Il metodo X-SETA (X-ray Spectral Emission combining Transmission and Absorption of continuous and line spectra) e’ stato messo a punto da ricercatori ENEA ed e’ oggetto di un brevetto PCT. Questa tecnica si basa su irraggiamento con raggi X di bassa energia (2-25 keV) e bassa potenza (2 W) di materiali plastici da identificare. Attraverso l’analisi di questi spettri si ricava la natura del polimero e la presenza di filler e di additivi (coloranti, fluidificanti, ritardanti di fiamma, ecc.), una volta che si e’ costruito il data base dei materiali che si vogliono riconoscere. Questa tecnica permette di discriminare plastiche nere (quindi non riflettenti), mentre le altre tecniche spettroscopiche non distruttive esistenti (NIR e Raman) non funzionano

X-SETA: una nuova tecnica in raggi X per discriminare plastiche nere

D. Pacella ENEA-Frascati

2

IL PROBLEMA DELLE PLASTICHE NERE…..

IDENII]YANDIHRIVEfu orpon &hils hov opti(o| spe(llosopy hin$ 0 {hntfir oplro0d to pl0sti6 reryding, olloving oper0tort

h olt.iondy ondt(orofdy somde nobtul oning inb fiei f0dffies. BY lAll ROBIRT9OII

n the U.S. alone in 2013, 33 million bns ofDlatrc wasEias senerarcd, maidy consisrintoT-conrainers and packaging, yet ontla9 percent was recycled. To help lift this

number md ensure qualiry 6are.ial for buye.s, itt essentialthe r€cycling industiy is propdly idenriq'ing the material ir

Mdy r€lding plahtl rely on rhe "dpdidcd recydei roidenrili plsncs in rhe q rem. Thi! d involk mdir ion,l r6Bcuch s a "fiq!lgr'or r "bun-dd-sniff r6t.' The 6oaIsr mdiseRnd:'-re polyolefitu 6;; od&Ga;F lad6 bakJ on wherh-d ile plrstic floats in . ware.-dete.gent sohrion. fhe burn-ad,snif merhod inwks rhe opmtor senins 6re to a mal Momt ofthe plaotic od sniffing the *olred frm6. Unfolluately, this 6led to nisidelrifierion ofthe plstic dd erablished a d.ngebusprotocol, c the fime Fon buning polln s 6 be qrdeb'roxic In additioD, th6e t6tr are only ideoiiryhg rhe bulk com-ponent ofthe mterial, but the pldric may, in reality, orsist ofmultiple mterials md addftlvei.

Not slrprisinglr $e pl6!i6 raycling indrstiJ. ha mad€ thechange to a more scielrific approach to plei.r idenrifierion md

22 PRU lAuslst2ot5

clEacEriation. Moy dab'tical $iencc t chnologis cd be aFplied to plartiq anallsis, iocluding the.md rnatsis dd chronatog-raph Howwe! in d industry requirins 6s sut$, dD* nerhodsffi not appopriate techniqug.

Another apprcach, called opti€l specnoscopy, n helpinSpldn6 rqclin3 compujc hsdle ruiffi;G;-6den y. mdiecbn"l.sier d*.r.p--, r" ,},ii re *ir liTiiF$;ior. r",the industryir futrc. In the follwirg *ctioro, redes wil g€t mundentanding of dre ditremt opdol sp<tuopis - R:m, NIRed FIIR- dd will be suid"d *'-'sh rh"

"d;r"6;d dF

tubge of sJ ,@hnolos/ * lppted rc pLsdc re.)ding.

Sampling in secondsMost appbpriate t€chniqus for rerycling ofplatio ac bascdon opti€l specrrcsopy, such s neu-inftued (NIR), Ramu orFourie. rnnsfom infrdd (FTIR) specrosopie. Thqe rechniques{e @p€ble olgiving on.lbivr io(ormadon on a sfple wirhin*,i. xr,,"",i.,r1:m* mT-am;*;-u-" ";"-;;;i .rdrse tectfologis in pldriG recyding. TLe insrmdts needed

IDENII]YANDIHRIVEfu orpon &hils hov opti(o| spe(llosopy hin$ 0 {hntfir oplro0d to pl0sti6 reryding, olloving oper0tort

h olt.iondy ondt(orofdy somde nobtul oning inb fiei f0dffies. BY lAll ROBIRT9OII

n the U.S. alone in 2013, 33 million bns ofDlatrc wasEias senerarcd, maidy consisrintoT-conrainers and packaging, yet ontla9 percent was recycled. To help lift this

number md ensure qualiry 6are.ial for buye.s, itt essentialthe r€cycling industiy is propdly idenriq'ing the material ir

Mdy r€lding plahtl rely on rhe "dpdidcd recydei roidenrili plsncs in rhe q rem. Thi! d involk mdir ion,l r6Bcuch s a "fiq!lgr'or r "bun-dd-sniff r6t.' The 6oaIsr mdiseRnd:'-re polyolefitu 6;; od&Ga;F lad6 bakJ on wherh-d ile plrstic floats in . ware.-dete.gent sohrion. fhe burn-ad,snif merhod inwks rhe opmtor senins 6re to a mal Momt ofthe plaotic od sniffing the *olred frm6. Unfolluately, this 6led to nisidelrifierion ofthe plstic dd erablished a d.ngebusprotocol, c the fime Fon buning polln s 6 be qrdeb'roxic In additioD, th6e t6tr are only ideoiiryhg rhe bulk com-ponent ofthe mterial, but the pldric may, in reality, orsist ofmultiple mterials md addftlvei.

Not slrprisinglr $e pl6!i6 raycling indrstiJ. ha mad€ thechange to a more scielrific approach to plei.r idenrifierion md

22 PRU lAuslst2ot5

clEacEriation. Moy dab'tical $iencc t chnologis cd be aFplied to plartiq anallsis, iocluding the.md rnatsis dd chronatog-raph Howwe! in d industry requirins 6s sut$, dD* nerhodsffi not appopriate techniqug.

Another apprcach, called opti€l specnoscopy, n helpinSpldn6 rqclin3 compujc hsdle ruiffi;G;-6den y. mdiecbn"l.sier d*.r.p--, r" ,},ii re *ir liTiiF$;ior. r",the industryir futrc. In the follwirg *ctioro, redes wil g€t mundentanding of dre ditremt opdol sp<tuopis - R:m, NIRed FIIR- dd will be suid"d *'-'sh rh"

"d;r"6;d dF

tubge of sJ ,@hnolos/ * lppted rc pLsdc re.)ding.

Sampling in secondsMost appbpriate t€chniqus for rerycling ofplatio ac bascdon opti€l specrrcsopy, such s neu-inftued (NIR), Ramu orFourie. rnnsfom infrdd (FTIR) specrosopie. Thqe rechniques{e @p€ble olgiving on.lbivr io(ormadon on a sfple wirhin*,i. xr,,"",i.,r1:m* mT-am;*;-u-" ";"-;;;i .rdrse tectfologis in pldriG recyding. TLe insrmdts needed

II

- "!-F

F R specrm, act,ture.ial s[E ftm hasharp ferures dlar de6!ethe finge.print for schseple Softwae for rhisqe of supling q?icalyprdid$ a s'mple Gsnrterh.€, ,llowing rheinstru$enr co be used b/dtr ope.aror aner very

approach, NIR, ha beenadopGd by muv Dlsdc---#rafos Mo e'rne. ue

build L\e rechiolosr inroautoh$ic plsdc sningequipneff. HddheldddiB operar€ in a poinr-and-shoor node similarro Lodheld Rdu in-sftuherrs. NIRspecrEde q?ic.tly colieaedover rhe spectral Bnge12000-4000.h-l usinga reflecrme apprcrchto n6uosr. TheGrrumdt iradiaresthe sople vith NIRlighr od masc$ i}!ediFcely reAefted |3dia-tion, genenring the NIRspatrom. NIR spectralt€tu6 are consideEblvbrcader md moe oxeElapped rhd their FTIRsp(th coun.erps andde dr6_!9!!info.h&riMich. A q?ical NIRspecnum (ofLDPE) is

Despire dre brcader

derlap, NIR is stiu apabte of idcnrit iqgdiFerent pldtic by @mpdisn asainsrspfttlal libhries. Howdea NIR is normallyo.Jy aprbre of idenriA,ins;-.6u1k-Dtffi . Il::-::::.-rF-_-_j#lll

ha bd confirmed ftough a mdbe. of.ewch eForls, indqding a Eut 4R Sus-tainabiliq', Inc. prcjeft dEr % tuqded by

and dsl is black pldric," the report shFd.

but the black sanple goenrcs a highly abso.bing specrun widr m spec$al fe, res.

Howfler FTIR is capable ofhesur,lJ/ inshtnrycotored nsrd pted6. hlhe/l srmPtins @chniqE adopEd for FnRI / neduements, ATR, lhe sdple beah only

Figure 3: Raman spectra of plastics

Fron top to bottom: PEI HDPE, PvC, pp and pS

Figure 4: NIR reflectance spectrum of LDPE

not dy addidves DEsenr. FTIRis the ori ii;,,riffi,q;6;I;". rd"."f -d;". I I

{ i

In the blackAlltiie oF(hse sp(u@Dic rcchniouesnaE ben adopEd tor t6r. rcutine tsin!

Drk-@lord smples Lead o very hishi!:9q!!!sr$S-$g{Ea.oi!lPrl1tu chat nrts the spectal featues ofrheplalic. A com Darison of rhe NIR soectr:

peerffq a few niffons into the smple,prftnting the high absorbda th{ mdi6the signars in Ramd dd NIR n6uremenrs. Sdda'd ATR n%uremens usinga didond dysl,l de op$le ofgeneEdnggood quali.n identifieble spcth even whenthe sdple ha trp to 25 to 30 percor a-bon black c filler, u shom in Figue 6.

ofpldiio. Howsd, rhetech qu6 d besqmied by (r sigqiEcmt sainpG;.fblack or hisb! colored pldti6. ftis fac.

remii6 one Ficdon of d1e rtdritlut specro*opy (fuqg4qlyj

24 PRU au9usi2015

oFwhite ad bhck LDPE smoles isiliii

Plastics Recycling Update USA, 2015

Figure 7:Figure 5:

NtR spectrc otwbite (top) antl bla.k(bottom) sarnples of LDPE

I1e spe.rra of the so harerialsoplesare vlrually idenrical and would be cureclyldendfied despite the heary arbor'blackloading ofth. {ir$ sanple. Al'R usins ad;amond crstal will hale poblcms ifthcblack "pla*i.'is a nuch softer n,rrerial suchas natunl or syntheri. rubbe!, bur rhcscmatedals do not no.mally fin<l rheifwayinro $e pla\ii6 leq'cling strcd. If neasuremcn$ on rhcsc matcrials are requiJed,then the dimond crrslal can be replacedwith a germnnm .ry$l $at is capable ofmeasuring carbon-black 6llcd stunplcs. ]}isis easil)' achieved.. a |omble nNiiuncnr.at!€r rhan a handheld.

A fu.the. adr"Drage of|TIR is attr ir capablc of idcnriE-iDg ni\tures ofmirerhls oraddi(iv.s wirhh plasri.s, suchas pla$icisers, fillds, nme retardds orcoatinss. This can bc uscful for checkinsthe purirr of smples ed ar help !rcvenidrc misusr ol comaninate<l or bannedmarerials iI rhe plastics r€ pro.esins. Theidcnrin.atio! ofnixtffrs hd been srearl].ennanced br dselopm€nr ofalgorithnx that{'illscarch

'he spectruh ofthe unknown

plsrjc agri$t stiectEl librries. deredingthe presence ofnrultiplc componen$ ln rhespecrrum nther dun ju$ rryi,rg ro 6nd rhcideniny ofthe bulk plaric alone. figurc 7shorvs rle resuir for an HDPEsample rliat$a conraminared wiih neady l0 pc.ccmPF. This .onlamiiarioD \r.s dctecredj$rprior ro the marcrial bcing rccyded x pureI lDPE.

Accepting l imitationsAs a sun!url, scioxihc jnstrunentaiionand nerhods are araildble tu ssisr io theplastic re.ading irdustrn Ranan, NIR .ndITIR rechniqu€s nav€ been adopred ard

F igure 6:

ffl fr spectra af ca tbo n-f illed poiystyrene(tap) and clear polystytene (baftam)

are applic$ie Io avas range ofmarerials ofvarying sik dd shape. Howwer, ifhighlycolored naterials *e often encountered,l'1IR is the onlr one ofthese technlquesrhar ll prove eFedive.

Andwharc we dpecr ftom rhis sFcein the fudr€? hsirumenrarion is becomingsmallerwirhotrr compromnes ro sp€ed mdpoformdc.. NlR has b€en incor!,rlall4into automdea pI!{[ ;rii,G.quipmcnr6ii iiilta;n;;ia; i6TEtk tEsnci.

-n- ' . . - ' . - - - ; .^ ',ne u.N. re. I . 'n8. .8anPlcurrenrlr lookins inro "NlR-dereciable"black plasdc packrgjng marc.jals, rcplacing

0_989415 HDPE 90.13019.8699

Mixture sear(h result showing acontaninatecl HDPE tanpte

carbon black as thc fillc Th.sc mlreriJsrnay Le adopted ir the future, bur tLere arenillions ofrcns of colorcd plasdcs.lrcadyin use rfi.tare i,r dangeroiending up inlodfills.

Dcv.lopmenr ol r!toh.red FTIRtechnologywould bchclplul, bur thcre arcsignin.anr L'driiers to E srntlng of dre

! planids to overcome to echieve rhis. for tiei i lnoment, the iadurrv rvllt have ro coniinue1119492! lle !l:!tlgrE!!!-q!g aas <+rrlliomelimitarions. PRU 1,,t,

IaD Robcr6on work s a scicnrisr inlhe soarcgic applicadoDs g!ou! wirhinrhc Ervironm.nral Healrh division rLPerlinElner, whl.l is bded in Yr.lthah,Mass. Hehas 35 years oferperienceworkiq in appliations relaring to in{iared,NIR and Rama{ instrunrcntadon.

tuprinte.l urh pdnissianfa,l |l6tics Re.r-clingupd^re, 24. Box 12270, ?oftldnd, OR97212 a270; (503) 233 1305, (503) 233-1 3 56 (fd): wtuu.phnicve.t,li"s.cotj.

Table 1: Comparison of optical spectroscopictechniques for plast ic recycl ing

NIR

ldentiiication ol <o6mon pla3tic (non-black)

!dentiJication ol commo. plastiG (bla<k) tr trldentilication of Grbon-f illed rubber materials tr trldentif i<atlon of additives/mixtures tr tr

trtr tr

*Uslng a germanium crystal

Figure 7:Figure 5:

NtR spectrc otwbite (top) antl bla.k(bottom) sarnples of LDPE

I1e spe.rra of the so harerialsoplesare vlrually idenrical and would be cureclyldendfied despite the heary arbor'blackloading ofth. {ir$ sanple. Al'R usins ad;amond crstal will hale poblcms ifthcblack "pla*i.'is a nuch softer n,rrerial suchas natunl or syntheri. rubbe!, bur rhcscmatedals do not no.mally fin<l rheifwayinro $e pla\ii6 leq'cling strcd. If neasuremcn$ on rhcsc matcrials are requiJed,then the dimond crrslal can be replacedwith a germnnm .ry$l $at is capable ofmeasuring carbon-black 6llcd stunplcs. ]}isis easil)' achieved.. a |omble nNiiuncnr.at!€r rhan a handheld.

A fu.the. adr"Drage of|TIR is attr ir capablc of idcnriE-iDg ni\tures ofmirerhls oraddi(iv.s wirhh plasri.s, suchas pla$icisers, fillds, nme retardds orcoatinss. This can bc uscful for checkinsthe purirr of smples ed ar help !rcvenidrc misusr ol comaninate<l or bannedmarerials iI rhe plastics r€ pro.esins. Theidcnrin.atio! ofnixtffrs hd been srearl].ennanced br dselopm€nr ofalgorithnx that{'illscarch

'he spectruh ofthe unknown

plsrjc agri$t stiectEl librries. deredingthe presence ofnrultiplc componen$ ln rhespecrrum nther dun ju$ rryi,rg ro 6nd rhcideniny ofthe bulk plaric alone. figurc 7shorvs rle resuir for an HDPEsample rliat$a conraminared wiih neady l0 pc.ccmPF. This .onlamiiarioD \r.s dctecredj$rprior ro the marcrial bcing rccyded x pureI lDPE.

Accepting l imitationsAs a sun!url, scioxihc jnstrunentaiionand nerhods are araildble tu ssisr io theplastic re.ading irdustrn Ranan, NIR .ndITIR rechniqu€s nav€ been adopred ard

F igure 6:

ffl fr spectra af ca tbo n-f illed poiystyrene(tap) and clear polystytene (baftam)

are applic$ie Io avas range ofmarerials ofvarying sik dd shape. Howwer, ifhighlycolored naterials *e often encountered,l'1IR is the onlr one ofthese technlquesrhar ll prove eFedive.

Andwharc we dpecr ftom rhis sFcein the fudr€? hsirumenrarion is becomingsmallerwirhotrr compromnes ro sp€ed mdpoformdc.. NlR has b€en incor!,rlall4into automdea pI!{[ ;rii,G.quipmcnr6ii iiilta;n;;ia; i6TEtk tEsnci.

-n- ' . . - ' . - - - ; .^ ',ne u.N. re. I . 'n8. .8anPlcurrenrlr lookins inro "NlR-dereciable"black plasdc packrgjng marc.jals, rcplacing

0_989415 HDPE 90.13019.8699

Mixture sear(h result showing acontaninatecl HDPE tanpte

carbon black as thc fillc Th.sc mlreriJsrnay Le adopted ir the future, bur tLere arenillions ofrcns of colorcd plasdcs.lrcadyin use rfi.tare i,r dangeroiending up inlodfills.

Dcv.lopmenr ol r!toh.red FTIRtechnologywould bchclplul, bur thcre arcsignin.anr L'driiers to E srntlng of dre

! planids to overcome to echieve rhis. for tiei i lnoment, the iadurrv rvllt have ro coniinue1119492! lle !l:!tlgrE!!!-q!g aas <+rrlliomelimitarions. PRU 1,,t,

IaD Robcr6on work s a scicnrisr inlhe soarcgic applicadoDs g!ou! wirhinrhc Ervironm.nral Healrh division rLPerlinElner, whl.l is bded in Yr.lthah,Mass. Hehas 35 years oferperienceworkiq in appliations relaring to in{iared,NIR and Rama{ instrunrcntadon.

tuprinte.l urh pdnissianfa,l |l6tics Re.r-clingupd^re, 24. Box 12270, ?oftldnd, OR97212 a270; (503) 233 1305, (503) 233-1 3 56 (fd): wtuu.phnicve.t,li"s.cotj.

Table 1: Comparison of optical spectroscopictechniques for plast ic recycl ing

NIR

ldentiiication ol <o6mon pla3tic (non-black)

!dentiJication ol commo. plastiG (bla<k) tr trldentilication of Grbon-f illed rubber materials tr trldentif i<atlon of additives/mixtures tr tr

trtr tr

*Uslng a germanium crystal

Non esiste ad oggi nessuna tecnica in raggi X per il riconoscimento di plastiche (la XRF e’ solo per i metalli o elementi pesanti) Le tecniche spettroscopiche NIR e Raman non funzionano con plastiche nere

Metodo X-SETA per discriminazione di plastiche nere

�  I raggi X non sono utilizzati per investigare materiali plastici, perche’ composti da atomi leggeri (C,H,O, N..) per i quali l’assorbimento fotoelettrico di raggi X e‘ debole. Conseguenza e’ che tutte le plastiche sono sostanzialmente indistinguibili

�  IDEE:

1 utilizzare anche lo scattering Compton (debole)

2 uso combinato di fluorescenza e di trasmissione

3 layout opportuno per realizzare l’idea fisica

Brevetto Italiano (Febbraio 2015)

PCT (Agosto 2016)

4

Strumento molto simile ad una pistola a raggi X Compatto, leggero (< 3 Kg), portatile

Plastiche RAEE campionate

Misura spot di 5-8 mm Plastiche con spessore costante sullo spot Durata della misura alcuni secondi

!"#$%&'()*+),(!$+"-()(*)&-&.+!+)SOFTWARE DI GESTIONE ED ANALISI

Con X-SETA abbiamo discriminato le seguenti famiglie:

PP, PE, PS, ABS, PC-ABS, PC/PA , PET, POM, PMMA PP+ talco PP+ carbonato calcio PP+ caolino PP+FV ABS+FV PC-ABS+FV PA+FV POM+FV PS+FR40, ABS+FR40, PC-ABS+FR40

7

Si sono poi effettuate le misure per 118 pezzi reali di scarto RAEE,

classificate in base alle specifiche stampate sul materiale plastico e/o

misurate con il sistema FTIR (trasmissione). Escludendo le famiglie i

cui pezzi erano insufficienti per avere una statistica, le valutazioni

sono state fatte su 104 di questi 118 pezzi.

I campioni non identificati sono 2 su 104, pari a circa 1.8%

Lo stesso hardware di una pistola a raggi X, ma fa molto di più…

9

Rivela: •  Coloranti (Ti, Fe, Cr) •  Filler (talco, Carb calcio, caolino, solfato di Ba..) •  Rinforzanti: fibra vetro •  Fluidificanti (Zn, Ca) •  Antifiamma (Br, fosfati, FR40..) •  Rivela anche elementi a basso Z (Si, P, Ca)

Limitazioni : •  Dipendenza dallo spessore •  Il polimero è riconosciuto, dopo la stima di tutti gli altri effetti •  Vi sono degenerazioni (PA/PC oppure ABS/SAN) •  Minore capacita’ di discriminazione PP e PE •  Deve essere istruito prima di poter riconoscere

E’ un sistema che riconosce cio’ che ha gia’ conosciuto. Deve essere quindi istruito, con opportuni database. Lavora tanto meglio quanto piu’ si limitano le famiglie

�  E’ stato messo a punto un prototipo di strumento da laboratorio

�  Una partnership tra ENEA (detentore del Know-how), la BMCR srl (mercato del riciclo delle plastiche) e XGLab srl (strumentazione raggi X) portera’ alla produzione e commercializzazione di questo strumento

�  Una versione veloce dovra’ essere sviluppata

PARTNERSHIP INDUSTRIALE

Siamo interessati a……….

�  conoscere meglio il mercato per questo strumento di laboratorio (compounders, recyclers…)

�  conoscere le esigenze specifiche per sviluppare database appropriati per lo strumento

�  Partnership per valorizzazione del mercato (strumento non esistente nel mercato)

�  Investitori per sviluppo di una versione veloce da integrare in un sistema automatico di selezione

GRAZIE