Iden­ti­fy­ing black pla­s­tics, par­ti­cu­lar­ly tho­se fil­led with car­bon black, remains a signi­fi­cant chall­enge in the pla­s­tics recy­cling indus­try. On the one hand, car­bon black fil­led pla­s­tics are essen­ti­al in many appli­ca­ti­ons due to their uni­que pro­per­ties. On the other hand, the­se same pro­per­ties pose signi­fi­cant chal­lenges for recy­cling. Despi­te the gro­wing demand for recy­cled pla­s­tics, the pre­sence of car­bon black in the­se mate­ri­als com­pli­ca­tes the sort­ing pro­cess. Con­ven­tio­nal near-infrared (NIR) spec­tro­sco­py, wide­ly used in recy­cling faci­li­ties, strug­gles to accu­ra­te­ly iden­ti­fy black plastics.

This artic­le exami­nes why NIR strug­gles with black pla­s­tics, out­lines the mar­ket demand and regu­la­to­ry dri­vers, and pres­ents seve­ral alter­na­ti­ve solu­ti­ons to over­co­me this obs­ta­cle. We also intro­du­ce seve­ral com­mer­ci­al­ly available pro­ducts, compa­re their capa­bi­li­ties, and look at future trends in black pla­s­tic iden­ti­fi­ca­ti­on technology.

Why NIR Spectroscopy Fails with Black Plastics

NIR tech­no­lo­gy works by emit­ting infrared light and mea­su­ring how it reflects off mate­ri­als. Dif­fe­rent mate­ri­als reflect light at dif­fe­rent wave­lengths, allo­wing the spec­tro­me­ter to deter­mi­ne their com­po­si­ti­on. Howe­ver, car­bon black, a pig­ment not only used in black pla­s­tics, absorbs almost all NIR signal. This absorp­ti­on pre­vents NIR spec­tro­me­ters from cap­tu­ring the neces­sa­ry data to iden­ti­fy the pla­s­tic type, making the tech­no­lo­gy inef­fec­ti­ve for black plastics.

The auto­mo­ti­ve and elec­tro­nics indus­tries, in par­ti­cu­lar, use black pla­s­tics exten­si­ve­ly, making this a signi­fi­cant recy­cling chall­enge. With the rise of cir­cu­lar eco­no­my prin­ci­ples and incre­asing envi­ron­men­tal awa­re­ness, there’s gro­wing pres­su­re to find alter­na­ti­ve ways to sort black pla­s­tics effectively.

Mar­ket Demand and Eco­no­mics of Black Pla­s­tic Recycling

Despi­te the dif­fi­cul­ty in sort­ing black pla­s­tics, the demand for recy­cled pla­s­tics con­ti­nues to grow. Indus­tries are incre­asing­ly loo­king for sus­tainable mate­ri­als due to envi­ron­men­tal regu­la­ti­ons, con­su­mer pres­su­re, and cost-saving initia­ti­ves. Black pla­s­tics are often found in dura­ble goods, pack­a­ging, and various indus­tri­al appli­ca­ti­ons, but the chall­enge in recy­cling them increa­ses ope­ra­tio­nal cos­ts and impacts profitability.

As busi­nesses adopt Exten­ded Pro­du­cer Respon­si­bi­li­ty (EPR) regu­la­ti­ons and cir­cu­lar eco­no­my prac­ti­ces, fin­ding effi­ci­ent sort­ing tech­no­lo­gies will be essen­ti­al to capi­ta­li­ze on the gro­wing mar­ket for recy­cled black pla­s­tics. Indus­tries that hea­vi­ly use black pla­s­tics will need to invest in tech­no­lo­gies that meet both regu­la­to­ry requi­re­ments and con­su­mer expec­ta­ti­ons for sustainability.

Alternative Technologies for Black Plastic Identification

Seve­ral tech­no­lo­gies have emer­ged as alter­na­ti­ves to NIR for the iden­ti­fi­ca­ti­on of black pla­s­tics, each with its advan­ta­ges and limitations:

1. Mid-Infrared (MIR) Spectroscopy

  • How it works: MIR spec­tro­sco­py uses a dif­fe­rent por­ti­on of the infrared spec­trum than NIR, allo­wing it to pene­tra­te the sur­face and inter­act with the che­mi­cal bonds of the mate­ri­al. This makes MIR more effec­ti­ve at iden­ti­fy­ing mate­ri­als, inclu­ding some black plastics.
  • Pros: Capa­ble of iden­ti­fy­ing mate­ri­als that absorb NIR, inclu­ding many black plastics.
  • Cons: More expen­si­ve and less por­ta­ble than NIR-based sys­tems. Requi­res spe­cia­li­zed equip­ment and may have slower pro­ces­sing times.
  • Pro­ducts:
    • Bru­ker ALPHA II FTIR sys­tem is a powerful MIR solu­ti­on, offe­ring detail­ed ana­ly­sis and accu­ra­te iden­ti­fi­ca­ti­on. Pri­cing starts around €25,000, making it sui­ta­ble for labo­ra­to­ries and indus­tri­al applications.

2. Raman Spec­tro­sco­py

  • How it works: Raman spec­tro­sco­py iden­ti­fies mate­ri­als based on how they scat­ter light, rather than absor­bing it. It is high­ly effec­ti­ve for ana­ly­zing black pla­s­tics, as the pre­sence of car­bon black does not inter­fe­re with its abili­ty to detect che­mi­cal structures.
  • Pros: Unaf­fec­ted by car­bon black, pro­vi­ding accu­ra­te results for black plastics.
  • Cons: More expen­si­ve and slower than NIR; requi­res careful cali­bra­ti­on and maintenance.
  • Pro­ducts:
    • Bru­ker Raman Spec­tro­me­ter: The BRAVO is a por­ta­ble, easy-to-use Raman spec­tro­me­ter desi­gned for accu­ra­te mate­ri­al iden­ti­fi­ca­ti­on, inclu­ding black pla­s­tics. Pri­cing typi­cal­ly starts around €30,000.

3. X-Ray Fluo­re­s­cence (XRF)

  • How it works: XRF tech­no­lo­gy uses X-rays to deter­mi­ne the ele­men­tal com­po­si­ti­on of a mate­ri­al. Sin­ce it works on a fun­da­men­tal ele­men­tal level, car­bon black does not affect its abili­ty to iden­ti­fy black plastics.
  • Pros: Can dif­fe­ren­tia­te bet­ween a wide ran­ge of mate­ri­als, inclu­ding black pla­s­tics. Fast and accurate.
  • Cons: Expen­si­ve and typi­cal­ly used for metals, limi­ting its broa­der use in pla­s­tics recycling.
  • Pro­ducts:
    • Ther­mo Fisher Niton XL5: A high-end XRF ana­ly­zer sui­ta­ble for lar­­ge-sca­­le recy­cling faci­li­ties. Pri­ces typi­cal­ly start around €20,000.

4. Visu­al Sort­ing with AI and Machi­ne Learning

  • How it works: This method com­bi­nes visu­al ima­ging tech­no­lo­gy with AI to “learn” the cha­rac­te­ristics of black pla­s­tics. It sorts mate­ri­als based on color, tex­tu­re, and other visu­al data, making it a ver­sa­ti­le solution.
  • Pros: Fast and sca­lable, espe­ci­al­ly in lar­ge recy­cling plants. Con­ti­nu­al­ly impro­ves through machi­ne learning.
  • Cons: Less effec­ti­ve with com­plex mix­tures or when visu­al cha­rac­te­ristics alo­ne are insufficient.
  • Pro­ducts:
    • Max AI offers an advan­ced sys­tem desi­gned spe­ci­fi­cal­ly for sort­ing black pla­s­tics. Max-AI uses AI-enhan­­ced visu­al reco­gni­ti­on and high-speed sort­ing to hand­le com­plex pla­s­tic was­te streams. Pri­cing for lar­­ge-sca­­le instal­la­ti­ons typi­cal­ly starts at €300,000, depen­ding on the faci­li­ty size and throughput.

Future Trends in Black Plastic Sorting Technologies

The future of black pla­s­tic iden­ti­fi­ca­ti­on lies in the deve­lo­p­ment of hybrid tech­no­lo­gies that com­bi­ne mul­ti­ple methods to impro­ve accu­ra­cy and speed. AI-dri­­ven inno­va­tions are expec­ted to play a signi­fi­cant role in impro­ving the effi­ci­en­cy of recy­cling faci­li­ties. The­se sys­tems will levera­ge machi­ne lear­ning to hand­le more com­plex mate­ri­al streams, refi­ning their iden­ti­fi­ca­ti­on pro­ces­ses over time.

Ano­ther pro­mi­sing trend is the explo­ra­ti­on of new pig­ments for black pla­s­tics that are detec­ta­ble by NIR sys­tems. By chan­ging the way the­se mate­ri­als absorb light, manu­fac­tu­r­ers could eli­mi­na­te the iden­ti­fi­ca­ti­on chall­enge altogether.

1. “Over­co­ming Black Pla­s­tic Recy­cling Chall­enge with MWIR Hyper­spec­tral Ima­ging Technology”

This artic­le dis­cus­ses the limi­ta­ti­ons of Near-Infrared (NIR) tech­no­lo­gy in detec­ting black pla­s­tics and intro­du­ces Mid-Wave Infrared (MWIR) Hyper­spec­tral Ima­ging as an effec­ti­ve alter­na­ti­ve. It pro­vi­des insights into how MWIR HSI enables accu­ra­te, con­t­act-free, real-time opti­cal sort­ing of black pla­s­tics, signi­fi­cant­ly enhan­cing recy­cling effi­ci­en­cy. Spe­cim (our soft­ware suite also sup­ports spe­cim came­ras, inclu­ding the FX50).

2. “Black Pla­s­tics Recy­cling: Towards A Cir­cu­lar Economy”

This pie­ce explo­res recent tech­no­lo­gi­cal deve­lo­p­ments that have made it pos­si­ble to sort black pla­s­tics not only by color but also by poly­mer type. It high­lights the eco­no­mic value unlo­cked for recy­cling com­pa­nies through the­se advance­ments and dis­cus­ses the chal­lenges and solu­ti­ons in achie­ving a cir­cu­lar eco­no­my for black pla­s­tics. Recy­cling Inside

3. “Recy­cling: What’s Ahead in Advan­ced Sort­ing Technology”

This artic­le del­ves into the future of recy­cling tech­no­lo­gies, focu­sing on advan­ced sort­ing methods. It covers the deve­lo­p­ment of add-on laser sen­sors that enable the detec­tion of black pla­s­tics, com­bi­ning mul­ti­ple tech­no­lo­gies in one sort­ing machine—including NIR spec­tro­sco­py, laser, elec­tro­ma­gne­tic, and AI-based came­ra sen­sors. Pton­line

4. “Recent Deve­lo­p­ments in Tech­no­lo­gy for Sort­ing Pla­s­tic for Recycling”

This rese­arch paper exami­nes the sta­­te-of-the-art in the iden­ti­fi­ca­ti­on and sor­ta­ti­on of pla­s­tic, high­light­ing recent deve­lo­p­ments in the appli­ca­ti­on of machi­ne lear­ning and arti­fi­ci­al intel­li­gence in pla­s­tics recy­cling. It pro­vi­des a com­pre­hen­si­ve over­view of com­mer­cial equip­ment for sort­ing pla­s­tic recy­cl­ables and dis­cus­ses the chal­lenges and oppor­tu­ni­ties in the field. MDPI

5. “Black Pla­s­tic Was­te Clas­si­fi­ca­ti­on by Laser-Indu­­ced Fluorescence”

This stu­dy inves­ti­ga­tes the poten­ti­al of laser-indu­­ced fluo­re­s­cence (LIF) tech­ni­ques for the iden­ti­fi­ca­ti­on of black poly­mers within pla­s­tic was­te streams. It offers insights into buil­ding effi­ci­ent sort­ing stra­te­gies appli­ca­ble in recy­cling plants, addres­sing the chal­lenges posed by the low spec­tral reflec­tance of black pla­s­tics. Sprin­ger

6. “Pla­s­tic Was­te Recy­cling, Appli­ca­ti­ons, and Future Pro­s­pects for a Sus­tainable Environment”

This review artic­le exami­nes emer­ging stra­te­gies for pla­s­tic was­te manage­ment, inclu­ding the pro­duc­tion of high-value-added pro­ducts from pla­s­tic was­te. It dis­cus­ses the pres­sing need to uti­li­ze pla­s­tic was­te for a cir­cu­lar eco­no­my and explo­res modern tech­ni­ques for was­te manage­ment, pro­vi­ding a broa­der con­text for recy­cling chal­lenges and solu­ti­ons. MDPI

7. “NIR Detec­ta­ble Black Colo­rants for Pla­s­tics” – Heu­bach Group

This artic­le explo­res inno­va­ti­ve colo­rants deve­lo­ped by Heu­bach that enable Near-Infrared (NIR) detec­tion of black pla­s­tics, faci­li­ta­ting more effi­ci­ent recy­cling pro­ces­ses. It dis­cus­ses the chal­lenges asso­cia­ted with tra­di­tio­nal car­bon black pig­ments and pres­ents solu­ti­ons alig­ning with cir­cu­lar eco­no­my goals. Heu­bach

8. “Black Pla­s­tic Pack­a­ging Hub” – WRAP

WRAP’s hub pro­vi­des com­pre­hen­si­ve infor­ma­ti­on on the recy­cla­bi­li­ty of black pla­s­tic pack­a­ging. It addres­ses com­mon ques­ti­ons about car­bon black pig­ments, NIR detec­ta­ble alter­na­ti­ves, and offers gui­dance for indus­try stake­hol­ders aiming to impro­ve recy­cling rates. WRAP

9. “Quick­ly Sepa­ra­ting Black Pla­s­tic Pack­a­ging Accor­ding to Type” – LANXESS

This press release intro­du­ces LANXESS’s Bay­fer­rox 303 T pig­ment, desi­gned to enhan­ce the Near-Infrared (NIR) detec­ta­bi­li­ty of black pla­s­tics. The artic­le dis­cus­ses how this deve­lo­p­ment aids in the effi­ci­ent sort­ing and recy­cling of black pla­s­tic pack­a­ging. Lan­xess

10. “Why Is Black Pla­s­tic Pack­a­ging So Hard to Recy­cle?” – World Eco­no­mic Forum

This artic­le exami­nes the chal­lenges of recy­cling black pla­s­tic pack­a­ging, focu­sing on the limi­ta­ti­ons of cur­rent was­te sort­ing sys­tems in detec­ting black pig­ments. It also high­lights initia­ti­ves by major UK super­mar­kets to redu­ce the use of non-recy­clable black pla­s­tic. WEF

Conclusion: Choosing the Right Solution for Your Business

For busi­nesses in the pla­s­tics recy­cling indus­try, black pla­s­tics repre­sent a uni­que chall­enge. While NIR spec­tro­sco­py has limi­ta­ti­ons due to car­bon black’s light absorp­ti­on pro­per­ties, seve­ral alter­na­ti­ve tech­no­lo­gies offer effec­ti­ve solu­ti­ons, inclu­ding MIR, Raman, and XRF. The choice of tech­no­lo­gy depends on the sca­le of your ope­ra­ti­ons, bud­get, and spe­ci­fic mate­ri­al needs.

For smal­ler ope­ra­ti­ons, por­ta­ble solu­ti­ons like the Mobi­le Bru­ker Raman Spec­tro­me­ter Bra­vo offer fle­xi­bi­li­ty. For lar­­ge-sca­­le recy­cling plants, sys­tems like Max-AI pro­vi­de advan­ced AI-dri­­ven sort­ing capa­bi­li­ties, while the Ther­mo Fisher Niton XL5 offers a robust XRF-based option.

The Black Pla­s­tic Dilemma

We’­re often asked about alter­na­ti­ves to NIR for detec­ting black pla­s­tics. The truth is that while NIR spec­tro­me­ters like the tri­na­miX NIR solu­ti­on can’t iden­ti­fy black pla­s­tics, it remains your best opti­on for most other mate­ri­als. Its ease of use, por­ta­bi­li­ty and speed is a huge step for­ward for many orga­ni­sa­ti­ons loo­king for solu­ti­ons to stream­li­ne their pro­ces­ses and make mate­ri­al detec­tion know­ledge available to ever­yo­ne, whe­ther they work in QA, logi­stics, warehousing or purchasing.

This artic­le was to explo­re why NIR is still the best start­ing point for recy­clers and what opti­ons exist for black pla­s­tics. To learn more about the­se pro­ducts, visit:

About us – Solid Scanner

Let’s take respon­si­bi­li­ty and recy­cle more pla­s­tics – ask us for sui­ta­ble solu­ti­ons. Our port­fo­lio includes solu­ti­ons ran­ging from small, por­ta­ble solu­ti­ons to indi­vi­du­al solu­ti­ons based on hyper­spec­tral came­ra sys­tems for simp­le, auto­ma­ted iden­ti­fi­ca­ti­on of pla­s­tics in the sort­ing pro­cess and for inline pro­cess con­trol, e.g. for homogeneity.

About trinamiX – the sensor technology company

tri­na­miX GmbH, based in Lud­wigs­ha­fen, was foun­ded in 2015 as a whol­ly owned sub­si­dia­ry of BASF SE. As a start-up within the com­pa­ny, it is not only ope­ra­tio­nal­ly inde­pen­dent, but also has uni­que access to the exper­ti­se and expe­ri­ence of the enti­re BASF Group. Its patent-pen­­ding tech­no­lo­gies enable peo­p­le and machi­nes to cap­tu­re the hid­den and invi­si­ble world around them to make bet­ter decis­i­ons and increase safety.