Extrusion International 5-2026

30 Extrusion International 5/2026 What FTIR mapping reveals about blend homogeneity Infrared imaging exposes themor- phology of the blends. Micro-ATR Fourier transform infrared (FTIR) reads the polymer surface with spa- tial resolution, giving a map rather than one averaged spectrum. PA12 and polypropylene have distinct in- frared bands, so we calculate a local PA12-to-PP ratio at every point in a speci c measured area. Across more than 1,000 spectra per region, the reactive blend held a PA12-to-PP ratio range of 2.6 to 4.8. The non-reactive blend ran from 1 to 12. Same material, same recycled loading, very different homogeneity due to the interface stabilization during upcycling with PP-g-MAH. The PA12-to-PP ratio range shows how the morphol- ogy domain composition varies across the material. The non-reac- tive blend held near-pure PA do- mains and near-pure PP domains, whereas the reactive blend has a more homogeneous composition throughout the material. No single instrument settles it. Rheology showed a higher storage modulus and a longer linear visco- elastic region, both signs of a stable interface. When rheology, me- chanical data and infrared imaging agree, that agreement explains why the material performs and predicts how it behaves in a part. Why development belongs on a benchtop twin-screw extruder This takes equipment built for iteration. Recycled feedstock var- ies batch to batch, so development means running many formulations and in many combinations of pro- cess parameters, including screw con gurations. A commercial line cannot do that cheaply, since it needs a large charge of material to run and a screw-con guration change can take a week. A bench- top twin-screw system, like the Thermo Scienti c™ Process 11 Par - allel Twin-Screw Extruder, runs the same trials on a handful of material and changes screw design and con- ditions quickly. Developing on a full production line, before conditions and screw design are settled, generates more waste than it saves. Settle the pro- cess window and compatibilizer loading on the bench, then trans- fer the proven parameters to a larger line. Moving validation in-line with process Raman The same benchtop setup can carry a real-time monitor. An in-line process Raman analyzer, such as the Thermo Scienti c™ MarqMetrix™ All-In-One Process Raman Analyzer, tracks reaction progress inside the extruder. Raman gives the process- time view, and FTIR mapping gives the nal distribution, closing the gap between the barrel and the n - ished part. That shortens validation, one of the real barriers to adoption. Reactive extrusion upcycling will scale when the industry treats it as a materials engineering problemwith measurable, repeatable value, not as an environmental gesture. That means validating upcycled feed- stock as a material system, not cer- tifying a recycled-content percent- age. The mechanical properties get the attention, but the distribution, dispersion and stabilization behind the morphology is the real proof the material will perform in the eld. Author LucivanBarros, Ph.D., is a senior ap- plications scientist at Thermo Fisher Scienti c. He specializes in polymer processing, reactive extrusion, rheol- ogy, injection molding and material development. Barros has more than 10 years of experience developing and optimizing advanced polymer systems, including nanocomposites and polymer blends, across research, processing and application. He holds a Ph.D. in macromolecular science and engineering from Case Western Reserve University. Thermo Fisher Scienti c www.thermo sher.com EXTRUSION TECHNOLOGIES Lucivan Barros, Ph.D., Senior Applications Scientist, Thermo Fisher Scienti c Thermo Scienti c Process 11 Parallel Twin-Screw Extruder with water bath and VariCut pelletizer setup