Twin-screw Extruder Research Articles

High moisture extrusion of soybean protein isolate: Effect of β-glucan on physicochemical properties of extrudates

This study is focused on exploring the effect of twin-screw high-moisture extrusion technology on the physico-chemical properties of β-glucan-soybean protein isolate (SPI-BG) extrudates. Different proportions (0 %, 1 %, 2 %, 3 %, 4 %, 5 %) of oat β-glucan (BG) were added with soybean protein isolate (SPI) to prepare SPI-BG extrudates. Results showed that the addition of a high quantity of β-glucan (BG) decreased the elastic properties of soy protein isolate (SPI) extrudates and then increased. The strengthening of S1-S2-S3 interactions (hydrogen bonds, hydrophobic interactions, and disulfide bonds) was primarily responsible for this trend. Fourier transform infrared (FTIR) spectral analysis was conducted which revealed that BG did not significant affect random coil content of SPI. However, it was observed that α-helix content was increased significantly and the β-sheet content was decreased. An observation was noted in the value of enthalpy (ΔH) change that increased from 115.80 J/g to 159.68 J/g.

Twin-screw extrusion of short Kevlar fiber–reinforced nylon composite filaments with enhanced mechanical properties and morphology

Twin-screw extrusion of short Kevlar fiber–reinforced nylon composite filaments with enhanced mechanical properties and morphology

Synthesis, characterization, thermal and mechanical behavior of polypropylene hybrid composites embedded with CaCO<sub>3</sub> and graphene nano-platelets (GNPs) for structural applications

<abstract> <p>In this study, ultra-fine graphene nanoplatelets (GNPs) were employed as nanofillers to reinforce a polypropylene (PP) matrix. This was done in conjunction with a polypropylene grafted maleic anhydride (PP-MAH) compatibilizer and calcium carbonate (CaCO<sub>3</sub>), with the aim of improving the mechanical and thermal properties of the resulting hybrid composites. Formulations for the hybrid composites were fabricated by compounding the PP matrix with varying weight percentages of GNPs (x = 0.5, 1.0, 1.5, 2.0), 2 wt.% CaCO<sub>3</sub>, and 5 wt.% PP-MAH using a twin-screw extruder followed by injection molding. This research thoroughly investigates the mechanical and thermal characteristics. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) results confirm the successful development of hybrid composites. The thermal stability, crystallization temperature, melting temperature, tensile strength, flexural strength, and impact resistance were evaluated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), universal testing machine, and low-velocity impact tester, respectively. The results indicated a significant improvement in the tensile strength of the PP matrix with the addition of GNPs, with the highest enhancement observed at 1.5 wt.% GNP loading, where the tensile strength reached a maximum of 40.54 MPa. This improvement was attributed to the proper interconnection, bonding, and compounding of PP with GNPs, thus leading to an increase in the load transfer efficiency.</p> </abstract>

Effect of thermal-oxidative and mechanical degradation of recycled LDPE on foaming

In this study, we investigated the effect of recycling process on the molecular structure, viscoelasticity and foaming behavior of low density polyethylene (LDPE). A series of LDPE samples with different recycling process was prepared by multiple extrusion using a twin-screw extruder. The molecular weight distribution (MWD) was characterized by gel permeation chromatography (GPC). Wider MWD indicated the generation of higher molecular weight products. Small-amplitude oscillation rheology showed reduced loss factors, indicating that the chain entanglement was more difficult to relax. Moreover, nonlinear viscoelasticity was investigated using elongational rheology and molecular stress function (MSF) model. The results showed a steeper strain hardening exhibited in recycled LDPE. The correlated parameter β in the MSF model indicated that the recycling did not significantly change the branches regularity in LDPE, while the increasing [Formula: see text], the other correlated parameter, indicated that the chain entanglement was enhanced, which was corresponded to the improvement of high molecular weight component. The foaming results revealed that the recycled LDPE had finer cellular structure and higher nucleation density. Moreover, despite adding PP and active CaCO3 to simulate the impurities, the foamability loss of these mixed samples was well restricted and still valuable. Recycled LDPE is instead better than its corresponding virgin one in foaming performance, exhibiting the application potential for further developments.

Influence of graphene nanoplatelets (GNPs) and aluminum-carbon layered double hydroxides (Al-C LDH) in polypropylene matrix of hybrid composite structures on the microstructure and mechanical performances

<p>In this study, a polypropylene (PP) matrix was reinforced with ultra-fine graphene nanoplatelets (GNPs), aluminum-carbon layered double hydroxides (Al-C LDHs), and calcium carbonate (CaCO<sub>3</sub>) as hybrid reinforcements, along with polypropylene grafted maleic anhydride (PP-g-MA) compatibilizers to create a novel thermoplastic-based hybrid composite polymer. The hybrid composite consisted of varying weight percentages of GNPs (ranging from 0.5 to 2.0 wt% in increments of 0.5), 2wt% Al-C LDH, 2wt % CaCO<sub>3</sub>, and 5wt % PP-g-MA. The bulk samples were manufactured using twin-screw extrusion followed by vertical injection molding. The developed hybrid composites were characterized using high-resolution scanning electron microscopy (HRSEM) for microstructural analysis, X-ray diffraction (XRD) for phase identification, X-ray photoelectron spectroscopy (XPS) for compositional analysis, and Fourier-transform infrared spectroscopy (FTIR) for functional group identification. Thermogravimetric analysis (TGA) was performed to assess thermal stability, crystallization, and melting behavior. Mechanical tests, including tensile, compressive, and three-point bending, were conducted to evaluate mechanical properties, while a low-velocity impact test assessed impact resistance. The results showed that the hybrid composite with a PP matrix embedded with 1.5 wt% GNPs, 2 wt% Al-C LDH, and 2 wt% CaCO<sub>3</sub> exhibited improved mechanical properties, achieving an ultimate tensile strength of approximately 45 MPa. This enhancement is attributed to the effective interconnection, bonding, and cross-linking of the reinforcements with the PP matrix, facilitating efficient load transfer, which makes it suitable for structural applications.</p>

Influence of graphene nanoplatelets (GnPs) and titanium dioxide (TiO2) hybrid fillers on the mechanical, thermal, and morphological performance of polypropylene (PP) based hybrid composites

The main objective of the present study was to investigate the influence of graphene nanoplatelets (GnPs), Titanium dioxide (TiO2), and its hybrid filler on the mechanical, thermal, and morphological characteristics of polypropylene (PP) based hybrid composites for structural applications. The PP-based hybrid composites were prepared using a twin-screw extruder for different filler compositions and then molded into tensile specimens with a mini-jet injection molding setup. Tensile, thermal, and morphological analyses were performed to determine the hybrid capability of the PP-based composites. The results showed that the values of tensile modulus and tensile yield strength show significant improvement at about ∼24% and ∼17%, while the values of elongation at break show a slightly decreasing trend for the hybrid composites compared to PP composites. The thermal stability analysis shows that the higher the hybrid filler content, the higher the temperature. Further, the SEM micrographs for the hybrid fillers show good dispersion onto the PP matrix, which may increase the interfacial adhesion between PP and fillers, thus enhancing the mechanical and thermal properties of PP-based hybrid composites.

Physical characteristics of extrudate with treatment composition ratio of mixed corn grit-soybean flour and extruder barrel temperature

Yellow corn is one of the key component in the production of popular RTE snacks. However, corn’s nutritional quality is relatively low, necessitating the incorporation of additional ingredients such as soybean to enrich the protein content. This study primarily aims to explore the influence of soybean flour composition and temperature of barrel on the physical characteristics of extrudates to produce nutrition-rich snacks. The materials utilized in the experiment consisted of corn grit (mesh 24) and soybean flour (mesh 80). Extrudates were produced using SYSLG twin-screw extruder machine with a 10-15 kg/h production capacity. The study’s experimental design employed two factors: the composition factor of soybean flour (at 10%, 20%, and 30%) and the final temperature of the barrel (at 120°C, 130°C, and 140°C). The physical attributes of the extrudates were assessed based on the parameters such as expansion ratio, extrudate texture (hardness), moisture content, WAI, and WSI. The study findings revealed that increased soybean flour composition reduced the expansion properties and a more rigid material texture. On top of that, all extrudates exhibited moisture content of less than 4% (wb). The water absorption index decreased with higher soybean flour composition and barrel temperature, whereas the water solubility index showed an increasing trend. Among the tested conditions, the treatment with temperature of the barrel of 140°C and a soybean ratio of 20% demonstrated the best quality results.

Reactive processing-microstructure-mechanical performance correlations in biodegradable poly(lactic acid)/expanded graphite nanocomposites.

Reactive extrusion is a promising method to prepare biodegradable nanocomposites with enhanced modulus, strength and toughness. In this study, biodegradable extended nanocomposites based on poly(lactic acid) (PLA)/expanded graphite (EG) were prepared by melt-compounding using a co-rotating twin-screw extruder. Effects of EG loading, aspect ratio, delamination and dispersion state on the mechanical and thermo-mechanical properties of PLA/EG nanocomposites were investigated. Adding the largest EG (EGL) nanoplatelets, having the average particle size of 48.2 μm and aspect ratio of 19.5, to the PLA matrix enhanced the Young modulus, tensile strength, ultimate strain and tensile toughness of the extended PLA sample with benzoyl peroxide (BP) between 40-100%. The observed enhancements originated from restricted PLA molecular motions, assisted PLA crystallization and intensified BP activity in extending the PLA chains. In contrast, EG nanofiller (EGS), with the lowest aspect ratio and size, lowered the PLA relaxation time and accelerated the PLA crystallization. This type of EG showed the weakest reinforcing effect on PLA. For the EG type (EGM) with an intermediate size and aspect ratio, it was observed that the presence of the nanoparticles had a negligible effect on the PLA molecular dynamic and reduced the PLA crystallization rate. The highest impact strength was observed for the PLA/EGM nanocomposite at 1 phr loading.

Physical characteristics of extrudate from mixed corn grit – red bean flour with treatment of moisture content and extruder barrel temperature

Extruded snacks, typically derived from low-protein corn, can significantly benefit from the incorporation of red beans to boost their protein content and enhance overall nutritional value. In this study, the influence of feed moisture content and extruder barrel temperature on various physical attributes of the extruded products, including moisture content, particle density, bulk density, expansion ratio, and hardness, were examined. The snacks were produced using a SYSLG-IV twin-screw extruder with a throughput capacity of 10-15 kg/h. The ingredient composition remained consistent, consisting of a 20% red bean flour and 80% corn grit blend. Three moisture content levels (14%-18%) and three different extruder barrel temperature settings (120°C-140°C) were used as variables. The results demonstrated that both variables significantly impacted the physical properties of the extruded snacks. Specifically, an increase in feed moisture content or a decrease in barrel temperature led to higher moisture content (1.01%-1.82%), greater particle density (0.17 g/cm3-0.39 g/cm3), increased bulk density (0.12 g/cm3-0.32 g/cm3), greater hardness (8.34 N-32.18 N), and reduced expansion ratio (2.17-3.0).

Citrus waste fibres for natural cosmetic and bioplastic packaging

In this work new biocomposite materials from wasted citrus peels has been validated for a value-added packaging and novel cosmetic products. Specifically, extracted natural fibres and dehydrated pulp from citrus fruit were combined with polylactic acid and other additives as materials for the production of bio-based packaging jars and cosmetic products. For the composition of the packaging an orange powder (dehydrated wastes) was found to be the best performing, while orange comminute, which results from milling the orange peel, was most suitable for composition of the cosmetic formulations. Polylactic acid was compounded with citrus fibres by up to 25 wt.% by twin screw extrusion and processed via injection moulding, one of the most widespread processing technologies for producing rigid packaging containers. Composites were characterized, defining their mechanical, morphological and thermal properties. Validation of packaging thermostability performance was performed by Heat deflection temperature in compliance to ISO75 and VICAT softening temperature in accordance with ISO306. Compatibility tests of packaging demonstrators with newly formulated cosmetic products has been investigated as well. An accelerated compatibility test of the cosmetic jars with water and oil-based simulants was performed at ambient temperature, -5 °C, and at 45 °C. The results indicated that new cosmetic packaging are not consistent with water-based cosmetic formulations but are compatible with products based on natural oils. While the price of these products is generally higher than those using conventional plastics, they are competitive for premium cosmetic brands.

Determination of mechanical performance of boric acid filled polypropylene based polymer composites

Polypropylene (PP) polymer, which is one of the indispensable materials of our daily life and stands out with its lightness, low cost and chemical resistance properties in the industry, was used. In industrial applications where the properties of polymers without additives are not sufficient, composite materials are produced by adding some additives to the polymer. In this experimental study, the mechanical properties of composites produced by adding boric acid (BA) to PP polymer at 5 wt.% (PP/5BA), 10 wt.% (PP/10BA) and 15 wt.% (PP/15BA) ratios were investigated. the effect of both BA filler and optimum BA filler ratio on mechanical properties were investigated. In the production of PP/BA composites, granules were first produced in an industrial twin screw extruder. Then, PP/BA composite tensile and impact test specimens were moulded on a conventional injection moulding machine. As a result, it was observed that the tensile modulus, tensile and yield strength of the composite materials decreased with increasing boric acid filler content in PP polymer. Depending on the boric acid filler content, the tensile strength decreased by an average of 18.3% and the breaking strength decreased by 14.8%. The lowest tensile modulus was obtained with a value of 2713 MPa at 10wt.% boric acid filler addition. The impact strength increased slightly at 5 wt.% boric acid filler addition and decreased at 10wt.% and 15wt.% boric acid filler addition.

Aynı Yöne Dönen Çift Vidalı Ekstrüderli Tandem Bir Termoplastik Geri Dönüşüm Sisteminde Vida Yapılanmasının İncelenmesi

Polymers have rapidly replaced the utilization of glasses, ceramics, metals, and organic textiles due to their cost-effectiveness, lightweight nature, and enhanced functionality. Nevertheless, as a consequence of their chemical composition, polymers undergo a protracted degradation process in natural environments, resulting in a significant accumulation of plastic waste since their inception. This accumulation has now reached a critical threshold, posing a substantial risk to both human well-being and the preservation of natural ecosystems. In the recycling process of thermoplastic wastes, it is necessary to subject them to two rounds of melting in order to obtain compounds. This practice results in a reduction of the recycling numbers associated with thermoplastics, which possess a finite recycling lifespan, by 50%. The present work involved the construction of a tandem recycling process, wherein molten waste polymers were immediately introduced into a co-rotating twin screw extruder. In contrast to alternative approaches, a process-dependent screw configuration has been devised for the twin-screw system employed in the delivery of molten material. The product derived from 80% waste thermoplastic was thereafter compared to the original product as an outcome of the aforementioned procedure. Properties similar to those of pure Polypropylene were seen in some physical and chemical characteristics.

Mechanical and thermal properties of a newly developed sepiolite filler-filled rPET/PA11 thermoplastic nanocomposites

The study examined the impact of sepiolite filler-filled nanocomposites in a novel recycled polyethylene terephthalate (rPET)/polyamide (PA11)/joncryl® blend. Sepiolite filler significantly improved the mechanical and thermal properties of nanocomposites. A twin-screw extruder and injection moulding machines were employed to manufacture five different formulations of nanocomposites. The tensile strength (37.6 MPa) and Young's modulus (944.25 MPa) of the blend NCS-0 improved with the addition of 2 phr of sepiolite. The tensile strength and Young's modulus of nanocomposites (NCS-2) were recorded at 41.3 MPa and 974.25 MPa, respectively. The lowest sepiolite filler content (2 phr) had the maximum tensile strength among all other ratios. The flexural strength of NCS-2 was recorded at 47.3 MPa. The tensile and flexural modulus of nanocomposites were significantly enhanced by incorporating 2 phr of sepiolite. The impact strength of NCS-2 (252.98 MPa) was much higher than NCS-8. The addition of sepiolite filler increased the glass transition temperature (Tg) by 38 %. The onset of decomposition temperature (Tonset) of the blend (NCS-0) improved by 20–22° Celsius (oC). Overall, nanocomposites with 2 phr sepiolite demonstrated the ultimate mechanical and thermal properties. These results explored new ways of using rPET/PA11 compatibilized blend in the automotive industry.

Mechanical, thermal, and morphological properties of poly(lactic acid) (PLA)/ recycled tyre rubber waste compatibilised with chain extender

The accumulation of waste tires in our society is a pressing issue due to their short lifespan and increasing demand. This research delves into effective methods for recycling waste tires, with a particular focus on utilizing biopolymers. Polylactic acid (PLA), a completely biodegradable polymer, has gained popularity for its biocompatibility, biodegradability, mechanical strength, and ease of processing. To overcome its toughness and thermal stability limitations, PLA has been blended with commercial polymers, such as rubber. Furthermore, the incorporation of recycled tire waste into PLA has demonstrated the potential to enhance its durability and strength. Joncryl® ADR is used as a chain extender and reactive compatibilizer to enhance the chemical interactions in the binary blend. The samples were prepared using a twin-screw extruder with the temperature between 150 and 190 ºC and 60 rpm of screw speed. These blends are then analyzed using a range of characterization techniques, including Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), tensile testing, and notched Izod impact testing. The blends were then characterized by chemical changes, thermal transitions, and thermal degradation. it was found that the 90/10/0.6 (PLA/RW/ADR) nanocomposite exhibited maximum thermal degradation.

Evolution of the Microstructure of PP-LDHs Nanocomposites during Melt Compounding: A Simulation Approach.

In the context of polymer-based nanocomposites containing layered nanofillers, the achievement of good extents of dispersion and distribution of the embedded nanoparticles and, even more, the obtainment of intercalated and/or exfoliated structures through melt compounding still represents a persistent challenge, especially in the case of anionic layered double hydroxides (LDHs)-containing systems and non-polar polymeric matrices. In this work, a simulation approach is proposed to evaluate the influence of the processing conditions on the morphology of polypropylene (PP)-based nanocomposites containing organomodified LDHs. In particular, the effect of the screw rotation speed and the feed rate on the final microstructure of the materials formulated through melt compounding in a twin-screw extruder was assessed. The rheological and morphological characterizations demonstrated that a more homogeneous morphology was achieved when high levels of both exploited processing parameters are selected. The results coming from the simulation of the processing were used to establish some relationships between the flow parameters and the microstructure of the nanocomposites, demonstrating that low residence times coupled with high local shear rates are required to ensure the achievement of homogenous morphologies, likely involving the occurrence of intercalation phenomena.

Mikroenkapsulasi Oleoresin Bawang Putih Menggunakan Ekstruder Ulir Ganda

Garlic (Allium sativum) oleoresin is susceptible to damage such as easily volatile and oxidized. It also has low solubility in water. Microencapsulation process is expected to overcome the disadvantages. The aim of this study was to obtain garlic oleoresin microcapsules through twin-screw extrusion process. The study was done by determining the suited carrier, i.e. β-cyclodextrin, dextrin, or maltodextrin, to be used in the microencapsulation of garlic oleoresin, and determining the optimum garlic oleoresin microencapsulation parameters based on response surface methodology (RSM) using the suited carrier. β-cyclodextrin was found to be the suitable carrier for the garlic oleoresin microencapsulation process using a twin-screw extruder. The usage of maltodextrin and dextrin was not possible due to the high viscosity of the mass observed which led to blockage. The modeling obtained through the RSM showed that the combination of the components (carrier, oleoresin, and water) was not ideal for optimum solubility and surface oil. However, the parameters and optimum formula obtained had good experiment repeatability. The optimum garlic powder obtained through the extrusion process showed low surface oil as much as 2.20% and solubility as much as 33.80%. The microencapsulated product exhibited better quality characteristics than commercial K brand spray-dried garlic powder. The extruded powder had nearly four-fold lower aroma intensity prior to dilution, and nearly three-fold higher aroma intensity when diluted in 60°C water.

Effect of cooking time and conditions on the textural properties of meat analogues developed for stew-based dishes

The aim of this study was to produce meat analogues for stews and determine the effects of cooking conditions and ingredients on their textural properties. Pea protein isolate (PPI) matrices were extruded at water contents between 40 and 60% w/w using a twin-screw extruder equipped with a cooling die. The extruded matrices were cooked for 1–3 h in water at 95 °C. The textural properties of the extrudates were determined using Texture Profile Analysis (TPA) before and after freezing and at various time points during cooking. Freezing-thawing leads to a minor reduction (∼5–15%) of the hardness of extruded PPI as compared to freshly extruded samples. The samples extruded at a water content of 40% w/w maintained some texture even after cooking, with a reduction in hardness of 57% after 1 h and 95% after 3 h, while the samples extruded at water contents of 50% and 60% became very soft already after 1 h of cooking with a reduction in hardness of ∼90%. Cooking extruded PPI in salt (2% w/w), vinegar (pH = 5.0) and garlic (5% w/w) reduced the hardness after cooking, with the largest reduction observed for the samples cooked in salt (42–67%), compared to 0–43% for the samples cooked in vinegar and 14–39% for the samples cooked in garlic. The effect of these condiments on the hardness was observed to increase with the water content of the extrudates. Stews from five representative international cuisines were prepared with selected samples to explore the suitability of such texturized meat analogues as ingredients for traditional foods. This study demonstrates that the use of meat analogues can be broadened to different preparation methods and to dishes from diverse cultures.

Influence of Extruder Setup and Process Parameters on the Product Quality of Solid Polymer Electrolytes Using Melt Extrusion

All solid-state batteries (ASSBs) are the next generation battery technology, in which the classical liquid electrolyte is replaced by an ion-conducting solid electrolyte. Materials that are used as solid-state electrolytes are generally divided into three material classes: polymers, oxides and sulphides. Electrolyte materials for ASSBs have been extensively studied regarding their electrochemical performance and their stability towards the electrode materials. Nevertheless, the commercialization of ASSBs is still hindered by the material availability in case of oxide and sulphides and the knowledge of scaled production routes for all kinds of separators. Polymers are readily available on the global market. It is thus possible to focus more on the processing routes of polymer based solid electrolytes. The use of thermoplastics as matrix for solid electrolytes (SE) offers the prospect of facile upscaling of the process from lab-scale to industrial series production by the implementation of a solvent-free thermal extrusion process. A twin-screw extruder offers the possibility of continuously mixing the SE components to produce homogeneous polymer based SEs. With two feeding units, the addition of the components takes place separately. This eliminates the time-consuming premixing step to obtain a homogeneous mixture.Thermoplastic poly(ethylene oxide) (PEO) is one of the most investigated materials for polymer based SEs due to its capability to dissolve alkali salts like Lithium(bistrifluoromethanesulfonyl)imide (LiTFSI). The thermal process route of PEO and its effect on the polymeric properties are currently under investigation. Previous works from our research group show that the processability of PEO not only depends on the conductive salt (LiTFSI), but also on its molecular weight and applied process parameters. [1] With increasing molecular weight, PEO becomes more sensitive towards thermal and mechanical load that leads to chain scissoring and degradation even at small load. Hence, the use of low molecular weight PEO (Mw= 100.000 g mol-1) is preferable for the dry production of PEO based SEs.The aim of this work is to optimize the extrusion process using a co-rotating twin-screw extruder for the solvent free production of solid PEO/LiTFSI-electrolytes in a molar ratio of 20:1 (EO:Li). Here, we investigate the effects of several extruder set-ups on the mixing behaviour of PEO and LiTFSI. Therefore, type of dosing and screw design are varied. The screw can be designed with conveying, kneading and mixing elements. We compare the dry extrusion of a premixed PEO/LiTFSI (20:1) batch with dry extrusion of PEO/LiTFSI (20:1) using two feeding units, one for each component. Process parameters, such as pressure at the extruder die, actual screw speed, torque and barrel temperature are continuously measured during the production. Process temperature and screw speed are optimized to avoid degradation of PEO. PEO/LiTFSI-electrolytes are produced with a process temperature of 90 °C across the whole extruder barrel and with screw speeds of 5 – 15 rpm. The products are evaluated by their homogeneity and quality of the extruded electrolytes. Optical microscopy is used for macroscopic evaluation and the Li-salt distribution is checked with SEM/EDX. Conductivity and rheology measurements are performed to determine the lithium concentration within the electrolyte and loss of molecular weight, respectively. For the determination of the ionic conductivity, we examine electrochemical impedance spectroscopy (EIS). The characterization of the extruded electrolytes helps to find optimal process parameters for the production of polymer based SEs.

Process- Structure Property Correlations in Continuous Processing of High-Power Anode Electrode Pastes for Application in Lithium Ion Batteries

For efficient production of lithium ion batteries, the growing demands on the production process, particularly a reduction of processing costs which consist of process time, material and energy consumption, must be met. In this regard, the mixing process is of particular importance. Its quality significantly determines the properties of the produced electrode paste and consequently the quality of the subsequent process steps (coating, drying) and finally of the electrochemical performance, including longevity and fast-charging capability, of the fabricated electrodes and batteries [1,2]. Process parameters and equipment setup for the mixing process need to be optimized such that the electrode compounds including active material(s), binder(s) and conductive additive(s) are efficiently deagglomerated, homogenized and dispersed while the generation of particle agglomerates due to insufficient deagglomeration and particle fractures due to excessive energy input is prevented. The state-of-the-art process for electrode paste production is a batch-type process which offers high flexibility particularly beneficial in the field of academic research where novel materials are commonly only available in limited scales. With respect to upscaling and production on industrial scales, though, innovative continuous mixing processes represent a promising alternative since they allow for continuous production of electrode pastes with consistently high quality [3].Therefore, in this study an innovative continuous mixing process using a twin-screw extruder is investigated for graphite-based aqueous anode formulations for high-power applications.For systematic adaption of relevant properties of the electrode paste (e.g., viscosity and particle size distribution) in the extrusion process the kneading concentration is one of the key machine parameters. Varying the kneading concentration for different active materials, a clear correlation to the change in viscosity can be observed up to a certain reversal point where the opposite behavior and a change of the rheological behavior is identified. The underlying mechanism for the observed behavior and its impact on the material and battery cell level is revealed by elaborating further analysis (particle size analysis, scanning electron microscopy, X-ray diffraction, electrochemical cycling). Beyond that, it is also presented how process and product properties correlate and how monitoring the machine parameters can indicate the observed change of the characteristics of the electrode paste.Literature[1] Haarmann, Matthias, Wolfgang Haselrieder, and Arno Kwade. "Extrusion‐Based Processing of Cathodes: Influence of Solid Content on Suspension and Electrode Properties." Energy Technology 8.2 (2020): 1801169.[2] Bockholt, Henrike, et al. "The interaction of consecutive process steps in the manufacturing of lithium-ion battery electrodes with regard to structural and electrochemical properties." Journal of Power Sources 325 (2016): 140-151.[3] Haarmann, Matthias, Desiree Grießl, and Arno Kwade. "Continuous Processing of Cathode Slurry by Extrusion for Lithium‐Ion Batteries." Energy Technology (2021): 2100250.

Untargeted screening of NIAS and cyclic oligomers migrating from virgin and recycled polyethylene terephthalate (PET) food trays

Polyethylene terephthalate is considered one of the most used and approved recycled plastic polymer as food contact materials (FCM); however, the fundamental details arising from the recycled content of PET trays in relation to processing conditions or extent of recycling are not well understood. In the present work, the presence and migration of different series of PET cyclic oligomers from industrially recycled trays were investigated using official food simulant D1 at 40 °C for 10 days. The trays were produced in two different facilities, using different extrusion processing technology, namely single and twin-screw extruder. Tested food packaging trays were produced from different ratios of virgin (vPET) and recycled PET (rPET), varying from 0% up to 100% w/w content. Analysis of the trays using MALDI-TOF-MS revealed a decrease in the molecular weight distribution (Mw) in rPET compared to virgin PET plastic. Untargeted screening with UHPLC-QTOF-MS, revealed the presence and migration of several intentionally added substances (IAS) as well as non-intentionally added substances (NIAS). The results demonstrated differences of the cyclic oligomers migration into the selected food simulant, depending on the rPET/vPET ratios as well as among the applied extrusion technology applied. Following multivariate analysis, marker compounds found to be benzyl butyl phthalate (BBP), butyl lactate, dodecenamide, 2-methyl-1,3-dioxolane, PET 2nd series cyclic dimer as well as PET 1st series cyclic dimer can be considered as marker compounds.