Journal articles: 'Twin-screw extrusion'

1

McGuire, P. A., S. Blackburn, and E. M. Holt. "Twin-Screw Extrusion Modelling." Advances in Science and Technology 45 (October 2006): 436–41. http://dx.doi.org/10.4028/www.scientific.net/ast.45.436.

Full text

Abstract:

A mathematical model has been derived to describe the pressure drop along the conveying and reverse sections of a partly full, fully intermeshing co-rotating twin-screw extruder. The model extends previous work on single screw extrusion, whereby the Benbow-Bridgwater model of paste rheology is combined with a force balance on a plug of paste. Experiments to verify the model have been carried out using a laboratory scale twin-screw extruder fitted with a hydraulic feeder and a modified barrel section allowing the collection of pressure data at numerous points along the extruder. Initial results suggested that the model was able to correctly predict the trends observed but underestimated the absolute values of the pressure. This was attributed to a change in the rheology of the paste due to viscous heating effects. Further experimental work was carried out to determine the relationship between the rheological parameters and temperature; this allowed a temperature correction to be made to the initial data after which the agreement with the predictions was greatly improved.

APA, Harvard, Vancouver, ISO, and other styles

2

Lewandowski, Adrian, and Krzysztof Wilczyński. "Modeling of Twin Screw Extrusion of Polymeric Materials." Polymers 14, no. 2 (2022): 274. http://dx.doi.org/10.3390/polym14020274.

Full text

Abstract:

An issue of modeling of twin-screw extrusion of polymeric materials is reviewed. The paper is written in honor of Prof. James L. White who was a pioneer in studying this issue. A global approach to process modeling is presented which includes solid polymer transport, polymer plasticating, and the flow of molten polymer. The methodology of CFD modeling of twin-screw extrusion is presented as well as the examples of this modeling which show the details of the process. Optimization and scaling of twin-screw extrusion are also covered. And finally, the future prospects of developments and research of twin screw extrusion is discussed.

APA, Harvard, Vancouver, ISO, and other styles

3

Nastaj, Andrzej, and Krzysztof Wilczyński. "Scaling-Up for the Counter-Rotating Twin Screw Extrusion of Polymers." Polymers 16, no. 19 (2024): 2720. http://dx.doi.org/10.3390/polym16192720.

Full text

Abstract:

A novel and original computer scaling-up system for the counter-rotating twin screw extrusion of polymers was developed. In the system, each scaling parameter (scaling criterion) may be considered as an objective function to be minimized for the single parameters or the functional relationships along the length of the screw. Scaling was based on the process simulation, which was performed using the comprehensive (or global) counter-rotating twin screw extrusion program called TSEM (Twin Screw Extrusion Model). The extrusion process was scaled by applying GASESTWIN (Genetic Algorithms Screw Extrusion Scaling) software developed for this purpose using genetic algorithms. Scaling up the extrusion process was carried out to enhance extrusion process throughput according to the scaling criteria specified by the single quantities of polymer melt temperature at the die exit and relative melting length, and by distributions along the screw length of the extrusion parameters of the polymer melt temperature and polymer plasticating. The global objective function had the lowest value for the selected extrusion parameters, which means the minimal differences between the values of the scaled-up processes and extrusion throughput was significantly increased. The solution to the problem of scaling the counter-rotating process presented in this paper complements the existing solutions for optimizing and scaling basic variants of the extrusion process, i.e., flood-fed and starve (metered)-fed single-screw extrusion, as well as co-rotating and counter-rotating twin-screw extrusion.

APA, Harvard, Vancouver, ISO, and other styles

4

Liu, Cheng-Ying, Shota Mikoshiba, Yutaka Kobayashi, et al. "Experimental Investigation and Numerical Simulation of a Self-Wiping Corotating Parallel Octa-Screw Extruder." Polymers 14, no. 6 (2022): 1201. http://dx.doi.org/10.3390/polym14061201.

Full text

Abstract:

An octa-screw extruder (OSE) is equipment for pelletizing, blending, and mixing polymers and composites. In this study, the degree of resin filling, residence time distribution (RTD) of molten resin, and temperature profile in the octa-screw extruder were evaluated both experimentally and numerically. An intermeshing corotating parallel octa-screw kneading extruder was used for the experiments. For the comparison study, the results obtained from this extruder were compared with the twin-screw extruder. High-density polyethylene was selected as the material for extrusion. Meanwhile, a numerical code, based on a 2.5 D finite element method derived from the Hele–Shaw flow model, was developed to simulate the octa-screw extrusion process. The empirical outcomes suggest that octa-screw extrusion exhibited a narrower RTD of the molten resin compared with the twin-screw extrusion, suggesting better extrudate quality. The octa-screw extrusion also showed a lower temperature profile than twin-screw extrusion. The results of the simulation were also found to be in good agreement with experimental measurements. Experimental and numerical investigations of an OSE enable detailed comprehension and visualization of resin distribution in the entire length of the OSE, thus providing advantages in terms of process optimization.

APA, Harvard, Vancouver, ISO, and other styles

5

Ji, Ho Suk, Geunyeop Park, and Hyun Wook Jung. "Rheological Properties and Melt Spinning Application of Controlled-Rheology Polypropylenes via Pilot-Scale Reactive Extrusion." Polymers 14, no. 15 (2022): 3226. http://dx.doi.org/10.3390/polym14153226.

Full text

Abstract:

Based on pilot-scale twin-screw reactive extrusion, the structural and rheological properties of controlled-rheology polypropylenes (CR-PPs) are investigated, where the effects of peroxide content and extrusion conditions such as screw configuration, extrusion temperature, and screw speed are prioritized. The active chain cleavage reaction by a small peroxide content of less than 600 ppm inside the extruder gradually increases the melt index and narrows the molecular weight distribution of CR-PPs, thereby affording favorable properties that are applicable to the fiber spinning process. The mechanical properties of CR-PPs are slightly degraded owing to the generation of unsaturated chain ends during the reactive extrusion, which suppresses crystal growth. Under all extrusion conditions, the chain scission and thermal degradation of polypropylene samples occur actively in the harsh twin-screw extruder compared with those in the mild twin-screw extruder. Finally, it is confirmed that CR-PPs can be suitably applied to the melt-spinning process for staple fiber production, thereby guaranteeing a more stable spinning process window against draw resonance instability.

APA, Harvard, Vancouver, ISO, and other styles

6

Sasimowski, Emil, and Łukasz Majewski. "Effect of the Intensive Plasticizing Zone Design on the Effectiveness of Corotating Twin-Screw Extrusion." Advances in Polymer Technology 2019 (April 16, 2019): 1–11. http://dx.doi.org/10.1155/2019/8518341.

Full text

Abstract:

The aim of this study was to investigate the effect of a new intensive plasticizing and mixing screw zone design on the effectiveness of the corotating twin-screw extrusion process for talc-filled polypropylene. The study determined the effect of the angle between the trilobe kneading elements forming the intensive plasticizing and mixing zone of the screws, the screw rotational speed, and the polypropylene/talc filling ratio on the characteristics of the extrusion process in a corotating twin-screw extruder EHP-2x20. The paper describes the experimental design and obtained results as well as the developed empirical models for selected variables of the extrusion process.

APA, Harvard, Vancouver, ISO, and other styles

7

Unlu, Emine, and James F. Faller. "RTD in twin-screw food extrusion." Journal of Food Engineering 53, no. 2 (2002): 115–31. http://dx.doi.org/10.1016/s0260-8774(01)00148-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

ISOBE, Seiichiro. "Extrusion Cooking with Twin Screw Extruder." Journal of the Society of Mechanical Engineers 92, no. 846 (1989): 435–37. http://dx.doi.org/10.1299/jsmemag.92.846_435.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Bur, Anthony J., and F. Mitchell Gallant. "Fluorescence monitoring of twin screw extrusion." Polymer Engineering and Science 31, no. 19 (1991): 1365–71. http://dx.doi.org/10.1002/pen.760311902.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Michaeli, W., A. Greefenstein, and U. Berghaus. "Twin-Screw extruders for reactive extrusion." Polymer Engineering and Science 35, no. 19 (1995): 1485–504. http://dx.doi.org/10.1002/pen.760351902.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Cassagnau, Philippe, Véronique Bounor-Legaré, and Bruno Vergnes. "Experimental and modelling aspects of the reactive extrusion process." Mechanics & Industry 20, no. 8 (2019): 803. http://dx.doi.org/10.1051/meca/2019052.

Full text

Abstract:

Reactive extrusion consists in using an extruder as a continuous chemical reactor. It is not a recent process, but it has been rapidly developed during the last thirty years and is more and more used today for the chemical modification of existing polymers. Among the various extrusion systems (single screw extruders, counter- and corotating twin-screw extruders, co-kneaders), the corotating twin-screw extruders are today the most widely used in reactive extrusion. After a presentation of the main advantages and drawbacks of the reactive extrusion, we will describe the way to control the process through on-line and in-line monitoring. Then, a modelling approach based on continuum mechanics will be presented, followed by an example of industrial applications of this particular process.

APA, Harvard, Vancouver, ISO, and other styles

12

Kaczor, Daniel, Krzysztof Bajer, Aneta Raszkowska-Kaczor, Grzegorz Domek, Piotr Madajski, and Pawel Szroeder. "The Influence of Multiple Extrusions on the Properties of High Filled Polylactide/Multiwall Carbon Nanotube Composites." Materials 15, no. 24 (2022): 8958. http://dx.doi.org/10.3390/ma15248958.

Full text

Abstract:

High filled polylactide/multiwall carbon nanotube composites were subjected to multiple extrusions using single-screw and twin-screw extruders. Samples of the processed composites were characterized by SEM, XRD, Raman, and FTIR spectroscopy. Thermal and rheological properties were investigated by DSC and MFR analyses. Subsequent extrusions resulted in decreased torque and process efficiency, which is a consequence of the viscosity reduction of PLA. Thermal and rheological properties of composites changed after each extrusion as well. As revealed by DSC analyses, cold crystallization temperature showed a tendency to decrease after each process, whereas cold crystallization enthalpy ΔHcc increased significantly. Melt flow rate, which is indicative of the polymer degradation, increased after each extrusion.

APA, Harvard, Vancouver, ISO, and other styles

13

Li, Xiao Ping, Zhi Sen Zhang, Hui Jin Xiao, Qiang Zeng, and Xiao An Zhang. "Corn-Rice Powder Extrusion Key Parameters in Twin-Screw Extrusion Process." Advanced Materials Research 815 (October 2013): 329–32. http://dx.doi.org/10.4028/www.scientific.net/amr.815.329.

Full text

Abstract:

To find the inner relations of extrusion key parameters, 2-factor and 3-level orthogonal experiments are carried out on the twin-screw extruder with the corn-rice powder as the materials. The factors are: screw rate and feed rate; the indices are: inner pressure, die outlet temperature and generator current. The results are analyzed by single index regression method, the results show that the screw rate has the significant influence on the variables of barrel inner pressure, die outlet temperature and generator current, while the feed rate only impact significantly on the barrel inner pressure and generator current. After the response analysis of the original variables, the desired experimental conditions are obtained. The parameters should be: screw rate=150rpm, feed rate=14rpm.

APA, Harvard, Vancouver, ISO, and other styles

14

Lewandowski, Adrian, and Krzysztof Wilczyński. "Computer modeling for polymer processing co-rotating twin screw extrusion – nonconventional screw configurations." Mechanik 90, no. 4 (2017): 282–87. http://dx.doi.org/10.17814/mechanik.2017.4.47.

Full text

Abstract:

Computer modeling of co-rotating twin screw extrusion with the use of nonconventional screw configurations has been presented. The polymer flow in the co-rotating twin screw extruder has been described. Some examples of three-dimensional, non-Newtonian modeling are shown. CFD generally oriented software ANSYS Polyflow has been used for modeling.

APA, Harvard, Vancouver, ISO, and other styles

15

Sikora, Janusz W., Volodymir Levytskyi, Volodymir Moravskyi, and Hendrik Gerlach. "Twin screw extrusion with Expancel foaming agent." Journal of Polymer Engineering 33, no. 6 (2013): 501–8. http://dx.doi.org/10.1515/polyeng-2013-0006.

Full text

Abstract:

Abstract Foam extrusion of polypropylene with a foaming agent, Expancel 950 MB 80 and 950 MB 120, was performed. The process was performed using a co-rotating twin screw extruder, with an 18 mm screw diameter and 24 L/D ratio. Dependences of polymer mass flow rate, extrudate foam rate, and polymer pressure on screw speed and foaming agent amount were determined and relevant conclusions were drawn.

APA, Harvard, Vancouver, ISO, and other styles

16

Cao, Ying Han, and Jin Nan Chen. "Effect of Wall Conditions on PVC-R Co-Rotating Conical Twin-Screw Extrusion." Advanced Materials Research 314-316 (August 2011): 419–27. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.419.

Full text

Abstract:

The effect of wall conditions on co-rotating conical twin-screw extrusion of rigid polyvinyl chloride (PVC-R) is studied. The relationship between the shear stress at the screw surface and the slip velocity of the flowing melt obeys Navier’s linear law. When the volumetric flow rate is 3.83×10-5 m3/s, the pressure difference between the entrance and exit of the metering section of co-rotating conical twin-screw extruder is calculated under different wall conditions by using the evolution technique in POLYFLOW. The 3D isothermal flow fields of PVC-R are also calculated. The results show that when the slip coefficient is smaller than 104 , the pressure difference is constant, corresponding to the full slip condition. When the slip coefficient is larger than 104 , with the slip coefficient decreasing, the pressure difference, and the gradients of velocity, pressure and shear rate decrease. The residual stress of the product is thus reduced. Therefore, increasing wall slip is good for the stability of polymer extrusion and the product quality. The dispersive and the distributive mixing of the twin-screw extruder under different slip conditions are also studied. Results show that when the slip coefficient is 107 , it is good for the co-rotating conical twin-screw PVC-R mixing extrusion.

APA, Harvard, Vancouver, ISO, and other styles

17

Hietala, Maiju, Jouko Niinimäki, and Kristiina Oksman. "The use of twin-screw extrusion in processing of wood: The effect of processing parameter and pretreatment." BioResources 6, no. 4 (2011): 4615–25. http://dx.doi.org/10.15376/biores.6.4.4615-4625.

Full text

Abstract:

In this study the effect of processing parameters on different types of wood raw material in extrusion was examined. The study consisted of two parts: the first part was to break and separate individual fibers from wood chips during the extrusion process; in the second part the effect of chemical pre-treatment and screw elements on wood raw material was evaluated. Statistical analysis was performed to evaluate the most important factors affecting wood particle size in extrusion. The statistical analysis showed that the screw speed is the main factor affecting wood fiber length in twin-screw extrusion of wood chips. This study showed that a twin-screw extruder can be used to separate individual fibers from wood chips, and the separated fibers have higher aspect ratios than the wood flour particles typically used in wood-polymer composites. When more fibrous and chemically softened wood raw material was used, fibers with even higher aspect ratios were obtained.

APA, Harvard, Vancouver, ISO, and other styles

18

Du, Bing, Yan Li Jiao, Zhi Qiang Huang, et al. "Ethanol Extraction of Flavonoids from Mungbean Skin after Twin-Screw Extrusion Process." Advanced Materials Research 393-395 (November 2011): 1203–11. http://dx.doi.org/10.4028/www.scientific.net/amr.393-395.1203.

Full text

Abstract:

In order to increase the extraction rate of flavonoids from mungbean skin, twin-screw extrusion process was used as a pretreatment method. After optimizing conditions of twin-screw extrusion process, effects on ethanol extracting flavonoids were studied. Results revealed that the best extrusion conditions were: screw speed at 268r/min, extrusion temperature at 115~120°C, feed moisture at 17% and feeding rate at 726g/min. Under these conditions, the optimum condition for ethanol extraction of flavonoids was: using 38% ethanol solution at a material-liquid ratio of 1:20 at 77.5 °C with 2.5 h. The average extraction rate of flavonoids from mungbean skin was 3.14%, comparing to rate of un-extruded material 2.07%, extraction rate raised by 51.5%. This pretreatment can destroy the density structure of mungbean skin which has great effect on the increase of extraction rate of flavonoids.

APA, Harvard, Vancouver, ISO, and other styles

19

Liu, Hua-Min, Ya-Nan Wei, Hao-Yang Li, An-Chi Wei, and Xue-De Wang. "Structural changes of polysaccharides isolated from corn bran by hydrothermal treatment after twin-screw extrusion." BioResources 15, no. 1 (2020): 1323–37. http://dx.doi.org/10.15376/biores.15.1.1323-1337.

Full text

Abstract:

The objective of this investigation was to elucidate the structural changes of the polysaccharides isolated by hydrothermal treatment of corn bran after twin-screw extrusion. The structures and antioxidant activities of the purified polysaccharides were investigated and compared by monosaccharide analysis, Fourier transform infrared (FT-IR), gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR). The results showed that the structures of the linkages and monosaccharide components of the purified polysaccharides were not affected strongly by the twin-screw extrusion pretreatment. However, the purified polysaccharides isolated from pretreated samples displayed significant differences in monosaccharide ratios, degree of branching/ linearity, and molecular weight. These physical changes may be related to the decrease of antioxidant activities of the polysaccharides. The present investigation contributes to the knowledge of how pretreatment by twin-screw extrusion affects the chemistry of corn bran polysaccharides. Results can be applied to improve the efficiency of hydrothermal extraction of polysaccharides from corn bran.

APA, Harvard, Vancouver, ISO, and other styles

20

Cao, Ying Han, and Jin Nan Chen. "Numerical Simulation of Effect of Slip Conditions on PVC Co-Rotating Twin-Screw Extrusion." Advanced Materials Research 189-193 (February 2011): 1946–54. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.1946.

Full text

Abstract:

The effect of wall conditions on the co-rotating parallel twin-screw extrusion of rigid polyvinyl chloride (RPVC) is studied. The relationship between the shear stress at the screw wall and the slip velocity of the flowing melt obeys Navier’s linear law. At zero pressure difference between the entrance and exit of the melting section of twin-screw extruder, the volumetric flow rate and 3D isothermal flow fields of RPVC are calculated under different wall slip conditions in the metering section of the twin-screw extruder by using the evolution technique in POLYFLOW. The results show that when the slip coefficient is smaller than 104Pa*s/m , the volumetric flow rate of the melt is constant, corresponding to the full slip condition. When the slip coefficient is larger than 104Pa*s/m , with the slip coefficient decreasing, the volumetric flow rate and viscosity increase, but the gradients of velocity, pressure, and shear rate decrease. The residual stress of the product is thus reduced. Therefore, increasing wall slip is good for the stability of polymer extrusion and the product quality. The dispersive and the distributive mixing of the twin-screw extruder under full slip and no slip conditions are also studied. Results show that the mixing performance under no-slip condition is better than under full-slip condition, but slip at the wall is good for the extrusion of heat-sensitive materials.

APA, Harvard, Vancouver, ISO, and other styles

21

Nastaj, Andrzej, and Krzysztof Wilczyński. "Optimization and Scale-Up for Polymer Extrusion." Polymers 13, no. 10 (2021): 1547. http://dx.doi.org/10.3390/polym13101547.

Full text

Abstract:

A review paper is presented on optimization and scale-up for polymer extrusion, both single screw and twin screw extrusion. Optimization consists in obtaining a multidimensional space of process output variables (response surface) on the basis of an appropriate set of input data and searching for extreme values in this space. Scaling consists in changing the scale of the process according to specific criteria, that is, changing the process while maintaining the scaling parameters at a level that is as close to the reference process parameters as possible. It consists in minimizing the differences between the parameters characterizing the reference process and the resulting process. This may be obtained by using optimization techniques leading to the minimization of discrepancies between the parameters of scaled processes. In the paper, it was stated that optimization and scale-up based on process simulation are more effective than those based on experimentation which is time consuming and expensive. The state-of-the-art on extrusion process modeling which is the basis of optimization and scale-up has been presented. Various optimization techniques have been discussed, and the Genetic Algorithms have been identified as powerful and very efficient. Optimization and scale-up based on the process simulation using Genetic Algorithms have been broadly reviewed and discussed. It was concluded that, up to date, there is a lack of optimization studies on the counter-rotating twin screw extrusion, although the global models of this process are known. There is also a lack of process simulation-based scaling-up studies, both on the counter-rotating twin screw extrusion and on the starve fed single screw extrusion. Finally, development perspectives in this field have been discussed.

APA, Harvard, Vancouver, ISO, and other styles

22

Talebizadeh, Alireza, and Pejman Rezayati-Charani. "Evaluation of pulp and paper making characteristics of rice stem fibers prepared by twin-screw extruder pulping." BioResources 5, no. 3 (2010): 1745–61. http://dx.doi.org/10.15376/biores.5.3.1745-1761.

Full text

Abstract:

Twin-screw extrusion pulping is a new approach to the manufacture of pulp for paper production, designed for non-wood feedstocks. In this research, the production of pulp from rice stem with a newly fabricated twin-screw extruder was investigated. Extrusion pulping of rice stem was conducted following a central composite design using a two-level factorial plan involving three process variables (pretreatment NaOH concentration: 0.4, 0.8, 1.2%; extrusion temperature: 40, 60, 80 o C; and extruder rotational speed: 55, 70, 85 rpm). Responses of pulp and handsheets properties to the process variables were analyzed using statistical software (MINITAB 15). As the results show, pulping of rice stem fiber can be done at a relatively short pretreatment time about 4 hours and a low NaOH concentration about 0.8% by twin-screw extruder with limit extrusion temperature of about 80 o C and extruder rotational speed about 85 rpm. The effect of pretreatment solvent, NaOH, is greatly enhanced by increases in the extrusion temperature. Analysis of the results revealed that this process has suitable potential to be used to obtain a pulp with yields approximately equivalent to neutral sulfite semichemical pulping at fixed kappa number, which is applicable for fluting paper and linerboard production.

APA, Harvard, Vancouver, ISO, and other styles

23

Schall, Christoph, Matthias Altepeter, Volker Schöppner, Sven Wanke, and Marina Kley. "Material-Preserving Extrusion of Polyamide on a Twin-Screw Extruder." Polymers 15, no. 4 (2023): 1033. http://dx.doi.org/10.3390/polym15041033.

Full text

Abstract:

In the context of plastics recycling, plastics are processed several times. With each new melting and extrusion the plastic is damaged, which can have a negative effect on product properties. To counteract material damage, special additives such as chain extenders can be used, which are intended to lead to post-polymerization during processing. A linear chain extension is important here, as branching and crosslinking can lead to uncontrolled changes in the plastic’s properties. To investigate the suitability of specialized linear chain extenders for polyamides, a polyamide-6 was processed several times and the molar mass distribution was evaluated after each extrusion cycle. Three series of tests were carried out. First, the plastic was regranulated five times without additives and twice with different concentrations of chain extenders on a twin-screw extruder. The results of the study show that not only can molar mass degradation be prevented with the appropriate additive, it is even possible to achieve a material buildup during processing. In our experiments, the polydispersity of the molar mass distribution remained nearly identical despite multiple extrusions. Thus, reactive extrusion makes it possible for the corresponding plastics to be processed several times without the molar mass decreasing. If a sufficiently pure material flow can be ensured during recycling, the number of possible reprocessings of the plastic can be significantly increased without the need to add virgin material.

APA, Harvard, Vancouver, ISO, and other styles

24

White, James L., Jongmin Keum, Hochul Jung, Kyunha Ban, and Sughun Bumm. "Corotating Twin-Screw Extrusion Reactive Extrusion-Devolatilization Model and Software." Polymer-Plastics Technology and Engineering 45, no. 4 (2006): 539–48. http://dx.doi.org/10.1080/03602550600554091.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Kaczor, Daniel, Krzysztof Bajer, Grzegorz Domek, Piotr Madajski, Aneta Raszkowska-Kaczor, and Paweł Szroeder. "Influence of Extruder Plasticizing Systems on the Selected Properties of PLA/Graphite Composite." Acta Mechanica et Automatica 16, no. 4 (2022): 316–24. http://dx.doi.org/10.2478/ama-2022-0038.

Full text

Abstract:

Abstract Twin-screw extrusion is a crucial method for the direct inserting of carbon micro- and nanomaterials into a polymer matrix using a dry procedure. The study aimed to determine the influence of the parameters of the twin-screw extruder plasticizing system on the dispersion homogeneity and distribution of graphite filler in the polylactide polymer matrix and overall quality of the composite. As a filler, a graphite micropowder with a 5 μm lateral size of platelets was used at concentration of 1 wt.%. Three configurations of screws with different mixing intensity and various types segments were considered in the extrusion experiments. Morphology and chemical structure of the obtained composites were examined using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR-ATR) and Raman spectroscopy. Differential scanning calorimetry (DSC) and melting flow rate measurements (MFR) were used to asses thermal and rheological properties of the composites. Samples of the polylactide/graphite composites were also subjected to mechanical tests. The results show that the selection of the mechanical parameters of twin-screw extruder plasticizing system plays a key role in the preparation of the homogeneous PLA/graphite composites. Incorrect selection of the screw geometry results in poor mixing quality and a significant deterioration of the mechanical and thermal properties of the composites. Optimised mixing and extrusion parameters can be the starting point for the design of efficient twin-screw extruder plasticizing system for fabrication of PLA composites with carbon nanotube and graphene fillers.

APA, Harvard, Vancouver, ISO, and other styles

26

Forster, Seth P., Erin Dippold, and Tiffany Chiang. "Twin-Screw Melt Granulation for Oral Solid Pharmaceutical Products." Pharmaceutics 13, no. 5 (2021): 665. http://dx.doi.org/10.3390/pharmaceutics13050665.

Full text

Abstract:

This article highlights the advantages of pharmaceutical continuous melt granulation by twin-screw extrusion. The different melt granulation process options and excipients are described and compared, and a case is made for expanded use of twin-screw melt granulation since it is a flexible and continuous process. Methods for binder selection are profiled with a focus on rheology and physical stability impacts. For twin-screw melt granulation, the mechanism of granulation and process impact on granule properties are described. Pharmaceutical applications of melt granulation ranging from immediate release of soluble and insoluble APIs, taste-masking, and sustained release formulation are reviewed, demonstrating the range of possibilities afforded by twin-screw melt granulation.

APA, Harvard, Vancouver, ISO, and other styles

27

Cassinath, Zen, Ming Xu Xia, Yan Huang, and Zhong Yun Fan. "Process Optimization and Microstructure Control for Twin Screw Rheo-Extrusion of an AZ91D Magnesium Alloy." Materials Science Forum 765 (July 2013): 439–43. http://dx.doi.org/10.4028/www.scientific.net/msf.765.439.

Full text

Abstract:

Twin screw rheo extrusion (TSRE) is a continuous semisolid forming process. The process takes advantage of the thixotropic properties of semisolid metal slurry and the high shear, controllable forward driving and self-sweeping capabilities of a counter rotating twin screw mechanism, offering a one-step melt-to-product forming technology with significant savings on energy consumption and manufacturing cost. The present work was carried out to investigate the feasibility of the process for processing light alloys using an AZ91D magnesium alloy and to obtain optimized operation conditions for microstructure control. A range of processing parameters was tested for slurry making, feeding and extrusion and their effect on microstructure development was examined. Experimental results showed that slurry with non-dendritic primary phase particles of various volume fractions, typical of semisolid microstructure, was obtained prior to extrusion. The particles were further refined during extrusion due to dynamic shearing applied by the twin screw mechanism under controlled thermal schemes and the final microstructure obtained after extrusion was dominated by uniformly distributed equiaxed, non-dendritic spherical grains and the average grain size was in the range of 35-80 mm, depending on processing parameters. This paper presents the performance of the TSRE process, focussing on process optimization and microstructure control. Mechanisms of microstructural refinement and particle morphology evolution are discussed.

APA, Harvard, Vancouver, ISO, and other styles

28

Takeuchi, Takumi, Panuwat Luengrojanakul, Hiroshi Ito, Sarawut Rimdusit, and Shinichi Shibata. "Effect of 9,9′-Bis(aryl)fluorene-modified nanocellulose, bamboo, and bagasse fibers on mechanical properties of various polymer composites." BioResources 20, no. 2 (2025): 4136–51. https://doi.org/10.15376/biores.20.2.4136-4151.

Full text

Abstract:

Impact-resistant automotive components were studied by evaluating the effects of single-screw and twin-screw extrusion on the mechanical properties of composites made from fluorene-modified nanocellulose (FCF) or bamboo fibers (30 wt%) combined with various polymers. Natural fiber composites were injection molded, and their mechanical properties were evaluated. Results showed that fluorene-modified nanocellulose exhibited improved dispersion when kneaded with polycarbonate and polyamide 6 using twin-screw extrusion, resulting in increases of over 5000 MPa in flexural modulus and over 40 MPa in maximum flexural stress compared to the base polymer. However, composites made with polyamide 66 and bamboo fibers required high injection molding temperatures exceeding 260 °C, which led to thermal degradation and reduced the fiber reinforcement effect on mechanical properties. The polypropylene showed weak interfacial compatibility with bamboo fibers, resulting in limited reinforcement effects in both single and twin-screw extrusion. The brittleness of the fibers did not significantly influence the elongation of the PP composite. Nonetheless, it exhibited less reduction in elongation compared to composites where bamboo or FCF was added to other polymers. Building on these results, flexural tests were conducted on composites combining high-impact polypropylene with natural fibers, demonstrating the potential for high-impact-resistant composite materials suitable for automotive applications.

APA, Harvard, Vancouver, ISO, and other styles

29

Egleston, Benjamin D., Michael C. Brand, Francesca Greenwell, et al. "Continuous and scalable synthesis of a porous organic cage by twin screw extrusion (TSE)." Chemical Science 11, no. 25 (2020): 6582–89. http://dx.doi.org/10.1039/d0sc01858a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Chevalier, Arthur, Philippe Evon, Florian Monlau, Virginie Vandenbossche, and Cecilia Sambusiti. "Twin-Screw Extrusion Mechanical Pretreatment for Enhancing Biomethane Production from Agro-Industrial, Agricultural and Catch Crop Biomasses." Waste 1, no. 2 (2023): 497–514. http://dx.doi.org/10.3390/waste1020030.

Full text

Abstract:

This study aimed to evaluate the effects of mechanical treatment through twin-screw extrusion for the enhancement of biomethane production. Four lignocellulosic biomasses (i.e., sweetcorn by-products, whole triticale, corn stover and wheat straw) were evaluated, and two different shear stress screw profiles were tested. Chemical composition, particle size reduction, tapped density and cellulose crystallinity were assessed to show the effect of extrusion pretreatment on substrate physico-chemical properties and their biochemical methane production (BMP) capacities. Both mechanical pretreatments allowed an increase in the proportion of particles with a diameter size less than 1 mm (from 3.7% to 72.7%). The most restrictive profile also allowed a significant solubilization of water soluble coumpounds, from 5.5% to 13%. This high-shear extrusion also revealed a reduction in cellulose crystallinity for corn stover (i.e., 8.6% reduction). Sweetcorn by-products revealed the highest BMP values (338–345 NmL/gVS), followed by corn stover (264–286 NmL/gVS), wheat straw (247–270 NmL/gVS) and whole triticale (233–247 NmL/gVS). However, no statistical improvement in maximal BMP production was provided by twin-screw extrusion. Nevertheless, BMP kinetic analysis proved that both extrusion pretreatments were able to increase the specific rate constant (from 13% to 56% for soft extrusion and from 66% to 107% for the high-shear one).

APA, Harvard, Vancouver, ISO, and other styles

31

Carvalho, Reyniel Ben, and Shreerang V. Joshi. "Solvent and catalyst free synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones by twin screw extrusion." Green Chemistry 21, no. 8 (2019): 1921–24. http://dx.doi.org/10.1039/c9gc00036d.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Wilczyński, Krzysztof, Andrzej Nastaj, Adrian Lewandowski, Krzysztof J. Wilczyński, and Kamila Buziak. "Fundamentals of Global Modeling for Polymer Extrusion." Polymers 11, no. 12 (2019): 2106. http://dx.doi.org/10.3390/polym11122106.

Full text

Abstract:

A review paper is presented on modeling for polymer extrusion for both single screw and twin-screw extrusion. An issue of global modeling is discussed, which includes modeling for solid conveying, melting, melt flow, and co-operation of the screw/die system. The classical approach to global modeling of the extrusion process, which is based on separate models for each section of the screw, i.e., solid transport section, melting and pre-melting sections, and the melt flow section is presented. In this case, the global model consists of the elementary models. A novel continuous concept of global modeling based on CFD (Computational Fluids Dynamics) computations is also presented, and a concept of using the DEM (Discrete Element Method) computation coupled with CFD computations is discussed.

APA, Harvard, Vancouver, ISO, and other styles

33

Göktürk, H., and K. Maki. "Twin screw extrusion of a metal particle dispersion." Journal of Applied Physics 79, no. 8 (1996): 4857. http://dx.doi.org/10.1063/1.362565.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Meyer, Marku S. "Risk and failure aspects in twin screw extrusion." Technology, Law and Insurance 5, no. 3-4 (2000): 147–53. http://dx.doi.org/10.1080/13599370010013549.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Purvis, Ian. "Baker Perkins: Twin-Screw Extrusion Creates Production Flexibility." Cereal Foods World 60, no. 3 (2015): 128–29. http://dx.doi.org/10.1094/cfw-60-3-0128.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

T. E. Lo, R. G. Moreira, and M. E. Castell-Perez. "MODELING PRODUCT QUALITY DURING TWIN-SCREW FOOD EXTRUSION." Transactions of the ASAE 41, no. 6 (1998): 1729–38. http://dx.doi.org/10.13031/2013.17316.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Ho, Thao Thi Thu, Kentaro Abe, Tanja Zimmermann, and Hiroyuki Yano. "Nanofibrillation of pulp fibers by twin-screw extrusion." Cellulose 22, no. 1 (2014): 421–33. http://dx.doi.org/10.1007/s10570-014-0518-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Shah, Ankur Harish, Shardul Bhusari, Ivan Djordjevic, and Terry W. J. Steele. "Twin screw extrusion of conductive citrate-based biomaterials." European Polymer Journal 110 (January 2019): 176–82. http://dx.doi.org/10.1016/j.eurpolymj.2018.08.010.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Kannadhason, S., Kurt A. Rosentrater, K. Muthukumarappan, and Michael L. Brown. "Twin Screw Extrusion of DDGS-Based Aquaculture Feeds." Journal of the World Aquaculture Society 41 (February 2010): 1–15. http://dx.doi.org/10.1111/j.1749-7345.2009.00328.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Rüppel, Annette, Susanne Wolff, Jan Philipp Oldemeier, Volker Schöppner, and Hans-Peter Heim. "Influence of Processing Glass-Fiber Filled Plastics on Different Twin-Screw Extruders and Varying Screw Designs on Fiber Length and Particle Distribution." Polymers 14, no. 15 (2022): 3113. http://dx.doi.org/10.3390/polym14153113.

Full text

Abstract:

Due to their valuable properties (low weight, and good thermal and mechanical properties), glass fiber reinforced thermoplastics are becoming increasingly important. Fiber-reinforced thermoplastics are mainly manufactured by injection molding and extrusion, whereby the extrusion compounding process is primarily used to produce fiber-filled granulates. Reproducible production of high-quality components requires a granulate in which the fiber length is even and high. However, the extrusion process leads to the fact that fiber breakages can occur during processing. To enable a significant quality enhancement, experimentally validated modeling is required. In this study, short glass fiber reinforced thermoplastics (polypropylene) were produced on two different twin-screw extruders. Therefore, the machine-specific process behavior is of major interest regarding its influence. First, the fiber length change after processing was determined by experimental investigations and then simulated with the SIGMA simulation software. By comparing the simulation and experimental tests, important insights could be gained and the effects on fiber lengths could be determined in advance. The resulting fiber lengths and distributions were different, not only for different screw configurations (SC), but also for the same screw configurations on different twin-screw extruders. This may have been due to manufacturer-specific tolerances.

APA, Harvard, Vancouver, ISO, and other styles

41

Kimmel, Vincent, Lorena Gräfe, Luca Grieser, et al. "Modeling Shear-Thinning Flow in Twin-Screw Extrusion Processes." Pharmaceutics 17, no. 3 (2025): 353. https://doi.org/10.3390/pharmaceutics17030353.

Full text

Abstract:

Background/Objective: Hot-melt extrusion has been established as a formulation strategy for various pharmaceutical applications. However, tailoring the screw configuration is a major challenge where 1D modeling is utilized. This usually requires specific screw parameters, which are rarely noted in the literature, especially when dealing with shear-thinning formulations. Methods: Therefore, a custom-made test rig was used to assess the behavior of various conveying and kneading elements using Newtonian silicon oil and shear-thinning silicon rubber. The pressure and the power were measured as a function of volume flow. A model was proposed characterizing the screw element behavior by six individual parameters A1, A2, A3, B1, B2, B3. Results: The experimental results regarding the behavior with respect to Newtonian fluids were in good agreement with the literature and were modeled in accordance with the Pawlowski approach. In terms of shear-thinning fluids, the influence of screw speed on pressure and power was quantified. An evaluation framework was proposed to assess this effect using two additional parameters. Based on a high number of repetitive measurements, a confidence interval for the individual screw parameters was determined that is suitable to highlight the differences between element types. Conclusions: Finally, geometrical screw parameters for Newtonian and shear-thinning flow were assessed and modeled, with three conveying and three kneading elements characterized.

APA, Harvard, Vancouver, ISO, and other styles

42

Zeng, Xian Kui, Shuai An, Chuan Sheng Wang, and Hui Guang Bian. "Research on Optimization of the Process Parameters of Bio-Packaging Materials by Response Surface Method." Key Engineering Materials 501 (January 2012): 279–82. http://dx.doi.org/10.4028/www.scientific.net/kem.501.279.

Full text

Abstract:

Response surface method was used to optimize the process parameters of bio-packaging materials, which is produced by twin-screw extruder, in order to get the best performance, increase production levels. In this article, we use the Design Expert software, Box-Behnken Design module, under the conduction that the mass fraction of starch, plant fiber, polyethylene were respectively 70%,10%,30%, and keep a plasticizer to 5%, We analysis and optimize the screw extrusion temperature, speed and filler content, The results showed that the optimum technology parameters for screw speed 101.81 r•min-1, extrusion temperature 118.24°Cand filler content is 5.0.

APA, Harvard, Vancouver, ISO, and other styles

43

Daurio, Dominick, Karthik Nagapudi, Lan Li, Peter Quan, and Fernando-Alvarez Nunez. "Application of twin screw extrusion to the manufacture of cocrystals: scale-up of AMG 517–sorbic acid cocrystal production." Faraday Discuss. 170 (2014): 235–49. http://dx.doi.org/10.1039/c3fd00153a.

Full text

Abstract:

The application of twin screw extrusion (TSE) in the scale-up of cocrystal production was investigated by using AMG 517–sorbic acid as a model system. Extrusion parameters that influenced conversion to the cocrystal such as temperature, feed rate and screw speed were investigated. Extent of conversion to the cocrystal was found to have a strong dependence on temperature and a moderate dependence on feed rate and screw speed. Cocrystals made by the TSE process were found to have superior mechanical properties than solution grown cocrystals. Additionally, moving to a TSE process eliminated the need for solvent.

APA, Harvard, Vancouver, ISO, and other styles

44

Pruthtikul, Rittirong, and Pitcha Liewchirakorn. "Preparation of Polypropylene Graft Maleic Anhydride (PP-g-MA) via Twin Screw Extrusion." Advanced Materials Research 93-94 (January 2010): 451–54. http://dx.doi.org/10.4028/www.scientific.net/amr.93-94.451.

Full text

Abstract:

Polypropylene (PP) samples grafted with Maleic Anhydride (MA) were prepared by reactive blending via co-rotating twin screw extrusion. The PP was functionalized in the presence of an optimized amount of precursor, Dicumyl Peroxide (DCP) and MA. The amounts of MA grafted on PP were checked by standard test method for acid number. Maleated PP as a compatibilizer with the highest acid number was added to PP/Polyamide 6 (PA6) and blended in the twin screw extrusion. It was found that the PP-g-MA enhanced tensile properties as well as the izod impact properties of notched samples of PP/PA6/PP-g-MA blends compared to neat polypropylene. The scanning electron microscope confirmed the good adhesion of PA6 on PP matrix.

APA, Harvard, Vancouver, ISO, and other styles

45

Jin Han, Yang, Trần Thị Thu Trà, and Lê Văn Việt Mẫn. "Co-extrusion of corn meal and polydextrose for making high fiber snack food: effects of extrusion screw speed on the product quality." Journal of Science and Technology Issue on Information and Communications Technology 17, no. 6 (2019): 10. http://dx.doi.org/10.31130/jst-ud2019-042e.

Full text

Abstract:

High fiber snack foods are attracting consumers’ attention due to their health benefits. In this research, corn meal and polydextrose are co-extruded with a twin-screw extruder and the screw speed is varied from 150 to 190 rpm. The objective of the research is to evaluate the effects of screw speed on the product quality. As the screw speed is increased, the expansion ratio and crispness of the fried extrudate are enhanced while the bulk density and hardness are reduced. Increase in screw speed results in increased water absorption index and water solubility index of the product. As the screw speed is increased, the mechanical energy of the extrusion process is also increased. The screw speed has significant correlation with the expansion index, bulk density and texture properties of the fried extrudate (p < 0.05).

APA, Harvard, Vancouver, ISO, and other styles

46

Fiedurek, Kacper, Paweł Szroeder, Marek Macko, Aneta Raszkowska-Kaczor, Marcin Borowicz, and Natalia Puszczykowska. "Introduction to Modelling the Correlation Between Grain Sizes of Feed Material and the Structure and Efficiency of the Process of Co-Rotating Twin-Screw Extrusion of Non-Flammable Composites with a Pla Matrix." Acta Mechanica et Automatica 16, no. 4 (2022): 301–8. http://dx.doi.org/10.2478/ama-2022-0036.

Full text

Abstract:

Abstract Co-rotating twin-screw extrusion is an energy consuming process that is generally not fully optimised to a specific polymer. From the point of view of the efficiency of the extrusion process, the starting material should be characterised by small grain sizes in comparison to the screw channel area, small surface area to volume ratio and small internal friction between the pellets. To develop a model describing the effect of polylactide (PLA) grain size on the extrusion efficiency, a series of experiments with a twin-screw extruder were carried out during which the energy consumption; torque on shafts and temperature of the melt on the extruder die were monitored. As feed material, both the neat PLA with different grain sizes and the PLA with expandable graphite fillers and phosphorous-based flame retardants were used. Morphology and dispersion quality of the composites were examined using scanning electron microscopy (SEM); flammability, smoke production, mass loss and heat release rates were tested using cone calorimetry; and melt flow rate was determine using a plastometer. Moreover, the thermal properties of the obtained composites were determined using differential scanning calorimetry (DSC). The results show that the choice of the starting material affects both the efficiency of the extrusion process and the flame retardancy properties of the composite materials.

APA, Harvard, Vancouver, ISO, and other styles

47

Okubo, Hikaru, Haruka Kaneyasu, Tetsuya Kimura, Patchiya Phanthong, and Shigeru Yao. "Effects of a Twin-Screw Extruder Equipped with a Molten Resin Reservoir on the Mechanical Properties and Microstructure of Recycled Waste Plastic Polyethylene Pellet Moldings." Polymers 13, no. 7 (2021): 1058. http://dx.doi.org/10.3390/polym13071058.

Full text

Abstract:

Each year, increasing amounts of plastic waste are generated, causing environmental pollution and resource loss. Recycling is a solution, but recycled plastics often have inferior mechanical properties to virgin plastics. However, studies have shown that holding polymers in the melt state before extrusion can restore the mechanical properties; thus, we propose a twin-screw extruder with a molten resin reservoir (MSR), a cavity between the screw zone and twin-screw extruder discharge, which retains molten polymer after mixing in the twin-screw zone, thus influencing the polymer properties. Re-extruded recycled polyethylene (RPE) pellets were produced, and the tensile properties and microstructure of virgin polyethylene (PE), unextruded RPE, and re-extruded RPE moldings prepared with and without the MSR were evaluated. Crucially, the elongation at break of the MSR-extruded RPE molding was seven times higher than that of the original RPE molding, and the Young’s modulus of the MSR-extruded RPE molding was comparable to that of the virgin PE molding. Both the MSR-extruded RPE and virgin PE moldings contained similar striped lamellae. Thus, MSR re-extrusion improved the mechanical performance of recycled polymers by optimizing the microstructure. The use of MSRs will facilitate the reuse of waste plastics as value-added materials having a wide range of industrial applications.

APA, Harvard, Vancouver, ISO, and other styles

48

Chen, Rong Yuan, Zan Huang, Wei Zou, Hai Chen Zhang, and Jin Ping Qu. "Preparation of Polypropylene/Sisal Fiber Composites and Study on the Fiber Orientation." Advanced Materials Research 989-994 (July 2014): 581–86. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.581.

Full text

Abstract:

The polypropylene/sisal fiber composites were prepared by twin screw extruder and vane extruder, respectively. The tensile test specimens perpendicular to the extrusion direction and parallel to the extrusion direction were prepared from the extruded composites, respectively. SEM observation showed that fiber orientation of sisal fiber in the composites was not obvious when the content of sisal fiber not more than 15wt%. When the content of sisal fiber was 15wt%, the ability to orientate of sisal fiber in the composite prepared by vane extruder was better than that of in the composite prepared by twin screw extruder, which the fiber orientation of sisal fiber was obvious along the extrusion direction in the composite. Tensile tests showed that the tensile properties of the composite parallel to the extrusion direction with 15wt% sisal fiber prepared by vane extruder were the best compared with other composites in this work. The results illustrated that the orientation of sisal fiber in the composites was beneficial to the improvement of the tensile properties of the composites.

APA, Harvard, Vancouver, ISO, and other styles

49

Bhattacharya, Suvendu. "Twin-screw extrusion of rice-green gram blend: Extrusion and extrudate characteristics." Journal of Food Engineering 32, no. 1 (1997): 83–99. http://dx.doi.org/10.1016/s0260-8774(97)00004-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Crawford, D. E., L. A. Wright, S. L. James, and A. P. Abbott. "Efficient continuous synthesis of high purity deep eutectic solvents by twin screw extrusion." Chemical Communications 52, no. 22 (2016): 4215–18. http://dx.doi.org/10.1039/c5cc09685e.

Full text

Abstract:

Mechanochemical synthesis has been applied to the rapid synthesis of Deep Eutectic Solvents (DESs), including Reline 200 (choline chloride : urea, 1 : 2), in a continuous flow methodology by Twin Screw Extrusion (TSE).

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Twin-screw extrusion'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles