PMID- 35215711 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20220301 IS - 2073-4360 (Electronic) IS - 2073-4360 (Linking) VI - 14 IP - 4 DP - 2022 Feb 18 TI - Data-Driven Modelling of Polyethylene Recycling under High-Temperature Extrusion. LID - 10.3390/polym14040800 [doi] LID - 800 AB - Two main problems are studied in this article. The first one is the use of the extrusion process for controlled thermo-mechanical degradation of polyethylene for recycling applications. The second is the data-based modelling of such reactive extrusion processes. Polyethylenes (high density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE)) were extruded in a corotating twin-screw extruder under high temperatures (350 degrees C < T < 420 degrees C) for various process conditions (flow rate and screw rotation speed). These process conditions involved a decrease in the molecular weight due to degradation reactions. A numerical method based on the Carreau-Yasuda model was developed to predict the rheological behaviour (variation of the viscosity versus shear rate) from the in-line measurement of the die pressure. The results were successfully compared to the viscosity measured from offline measurement assuming the Cox-Merz law. Weight average molecular weights were estimated from the resulting zero-shear rate viscosity. Furthermore, the linear viscoelastic behaviours (Frequency dependence of the complex shear modulus) were also used to predict the molecular weight distributions of final products by an inverse rheological method. Size exclusion chromatography (SEC) was performed on five samples, and the resulting molecular weight distributions were compared to the values obtained with the two aforementioned techniques. The values of weight average molecular weights were similar for the three techniques. The complete molecular weight distributions obtained by inverse rheology were similar to the SEC ones for extruded HDPE samples, but some inaccuracies were observed for extruded UHMWPE samples. The Ludovic((R)) (SC-Consultants, Saint-Etienne, France) corotating twin-screw extrusion simulation software was used as a classical process simulation. However, as the rheo-kinetic laws of this process were unknown, the software could not predict all the flow characteristics successfully. Finally, machine learning techniques, able to operate in the low-data limit, were tested to build predicting models of the process outputs and material characteristics. Support Vector Machine Regression (SVR) and sparsed Proper Generalized Decomposition (sPGD) techniques were chosen to predict the process outputs successfully. These methods were also applied to material characteristics data, and both were found to be effective in predicting molecular weights. More precisely, the sPGD gave better results than the SVR for the zero-shear viscosity prediction. Stochastic methods were also tested on some of the data and showed promising results. FAU - Casteran, Fanny AU - Casteran F AUID- ORCID: 0000-0002-2600-5198 AD - Centre National de la Recherche Scientifique, Ingenierie des Materiaux Polymeres, Universite Claude Bernard Lyon 1, 15 Boulevard Andre Latarjet, 69622 Villeurbanne, France. FAU - Delage, Karim AU - Delage K AD - Centre National de la Recherche Scientifique, Ingenierie des Materiaux Polymeres, Universite Claude Bernard Lyon 1, 15 Boulevard Andre Latarjet, 69622 Villeurbanne, France. FAU - Hascoet, Nicolas AU - Hascoet N AD - ESI Group Chair@PIMM, Arts et Metiers Institute of Technology, 151 Boulevard de l'Hopital, 75013 Paris, France. FAU - Ammar, Amine AU - Ammar A AD - ESI Group Chair@LAMPA, Arts et Metiers Institute of Technology, 2 Boulevard du Ronceray, 49035 Angers, France. FAU - Chinesta, Francisco AU - Chinesta F AD - ESI Group Chair@PIMM, Arts et Metiers Institute of Technology, 151 Boulevard de l'Hopital, 75013 Paris, France. FAU - Cassagnau, Philippe AU - Cassagnau P AD - Centre National de la Recherche Scientifique, Ingenierie des Materiaux Polymeres, Universite Claude Bernard Lyon 1, 15 Boulevard Andre Latarjet, 69622 Villeurbanne, France. LA - eng PT - Journal Article DEP - 20220218 PL - Switzerland TA - Polymers (Basel) JT - Polymers JID - 101545357 PMC - PMC8877389 OTO - NOTNLM OT - artificial engineering OT - machine learning OT - polyethylene recycling OT - polymer extrusion COIS- The authors declare no conflict of interest. EDAT- 2022/02/27 06:00 MHDA- 2022/02/27 06:01 PMCR- 2022/02/18 CRDT- 2022/02/26 01:06 PHST- 2021/11/11 00:00 [received] PHST- 2022/02/10 00:00 [revised] PHST- 2022/02/15 00:00 [accepted] PHST- 2022/02/26 01:06 [entrez] PHST- 2022/02/27 06:00 [pubmed] PHST- 2022/02/27 06:01 [medline] PHST- 2022/02/18 00:00 [pmc-release] AID - polym14040800 [pii] AID - polymers-14-00800 [pii] AID - 10.3390/polym14040800 [doi] PST - epublish SO - Polymers (Basel). 2022 Feb 18;14(4):800. doi: 10.3390/polym14040800.