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Krzysztof Wilczynski - One of the best experts on this subject based on the ideXlab platform.

  • Optimization for Starve Fed/Flood Fed Single Screw Extrusion of Polymeric Materials.
    Polymers, 2020
    Co-Authors: Andrzej Nastaj, Krzysztof Wilczynski
    Abstract:

    A novel computer optimization system for flood fed/starve fed Single Screw Extrusion of polymeric materials has been developed. This coupled system allows us to optimize Single Screw Extrusion both flood fed and starve fed. Optimization is based on process simulation which is performed using global Extrusion model GSEM (Global Screw Extrusion Model). The process is optimized with the use of GASEO (Genetic Algorithms Screw Extrusion Optimization) procedures which were developed using Genetic Algorithms. An example of optimization of Extrusion process parameters has been presented to maximize Extrusion output and minimize specific energy consumption. Optimization has been performed in a unique and original way in a coupled manner when both modes of feeding were allowed. The studies have shown that the optimal process is Extrusion with starving. In this case, the global objective function reached the highest value, and Extrusion throughput was relatively high and specific energy consumption was minimal.

  • global modeling of Single Screw Extrusion with slip effects
    International Polymer Processing, 2019
    Co-Authors: Adrian Lewandowski, Krzysztof Wilczynski
    Abstract:

    Abstract An extensive study is presented on the polymer melt flow with slip effects in a Single Screw Extrusion process. Fully three-dimensional non-Newtonian FEM computations are performed to desi...

  • computer modeling for Single Screw Extrusion of wood plastic composites
    Polymers, 2018
    Co-Authors: Krzysztof Wilczynski, Adrian Lewandowski, Kamila Buziak, Andrzej Nastaj
    Abstract:

    Experimental and theoretical studies have been performed on the Single-Screw Extrusion of wood–plastics composites. Experimental research has been carried out on the flow and melting of polypropylene (PP)-based composites with different wood flour (WF) content in the Single-Screw extruder. Based on these experimental observations, elementary models of the process phenomena have been proposed and a global model of the process has been developed. This global computer model includes the models of solid conveying, melting dependent on the wood flour content, melt flow in the Screw, and melt flow in the die. 3-D non-Newtonian finite element method (FEM) Screw pumping characteristics have been applied to model the melt flow in the metering section of the Screw. The model predicts the Extrusion output, pressure and temperature profiles, melting profile, and power consumption. The model has been validated experimentally. An effect of material slip on the extruder operation has been discussed including both slipping in the Screw/barrel surfaces and in the extruding die.

  • Computer Modeling for Single-Screw Extrusion of Wood⁻Plastic Composites.
    Polymers, 2018
    Co-Authors: Krzysztof Wilczynski, Adrian Lewandowski, Kamila Buziak, Andrzej Nastaj
    Abstract:

    Experimental and theoretical studies have been performed on the Single-Screw Extrusion of wood–plastics composites. Experimental research has been carried out on the flow and melting of polypropylene (PP)-based composites with different wood flour (WF) content in the Single-Screw extruder. Based on these experimental observations, elementary models of the process phenomena have been proposed and a global model of the process has been developed. This global computer model includes the models of solid conveying, melting dependent on the wood flour content, melt flow in the Screw, and melt flow in the die. 3-D non-Newtonian finite element method (FEM) Screw pumping characteristics have been applied to model the melt flow in the metering section of the Screw. The model predicts the Extrusion output, pressure and temperature profiles, melting profile, and power consumption. The model has been validated experimentally. An effect of material slip on the extruder operation has been discussed including both slipping in the Screw/barrel surfaces and in the extruding die.

  • A computer model for starve-fed Single-Screw Extrusion of polymer blends
    Advances in Polymer Technology, 2017
    Co-Authors: Krzysztof Wilczynski, Andrzej Nastaj, Krzysztof Wilczyński
    Abstract:

    A new computer model has been developed to simulate a starve-fed Single-Screw Extrusion process of polymer blends. This is a composite model, which is based on combining melt conveying models with new fusion models for polymer blends. The model is able to predict pressure and temperature profiles, filling of the Screw and rate of polyblend fusion. Computer calculations were executed for Extrusion of high-density polyethylene and polystyrene blend at various technological conditions, and fill factor, pressure, temperature, and fusion profiles were calculated. The results of simulation studies were verified by experiment.

Yih Mon Jaw - One of the best experts on this subject based on the ideXlab platform.

  • Starch transitions and their influence on flow pattern during Single-Screw Extrusion cooking of rice flour
    Food and Bioproducts Processing: Transactions of the Institution of of Chemical Engineers Part C, 1999
    Co-Authors: A. N.i. Yeh, Tsai Quen Wu, Yih Mon Jaw
    Abstract:

    The starch transitions and flow pattern of rice flour (40% moisture content) during Single-Screw Extrusion cooking at different temperatures have been investigated. In the first 21.5 cm of the extruder with a cooled barrel, the rice flour remained in powder form and moved easily. The flow of rice flour behaved as a plug flow reactor. At the end of the cooling zone, the swelling of starch granules resulted in a gradual increase in the degree of starch gelatinization which slowed down the flow of materials. Confirmed by the measurements of intrinsic viscosity and gel permeation chromatography (GPC), the degradation of starch molecules occurred simultaneously with the melting of starch granules in the heating zone. Increasing barrel temperature resulted in more starch degradation and longer residence time. The flow pattern was changed from a plug flow reactor to a continuous stirred tank reactor.

  • Modeling residence time distributions for Single Screw Extrusion process
    Journal of Food Engineering, 1998
    Co-Authors: A. I. Yeh, Yih Mon Jaw
    Abstract:

    The residence time distribution (RTD) of rice flour during Single-Screw Extrusion cooking at various operating conditions and Screw profiles has been measured and a model describing RTD has been developed. Increasing the feed rate caused rite reduction in residence time. High Screw speed resulted in short residence rime, but large dispersion number: The non-flight element yielded the longest residence, but smallest dispersion number among three sa ew elements rested. A mathematical model consisting of a plug flow reactor in series with a continuous stirred tank reactor cross-flowing with a dead volume fitted well the experimental data with correlation coefficients (r(2)) higher than 0.988. The analysis showed that P (fraction of plug flow reactor) varied from 0.38 to 0.65. A high Screw speed or fitting a mixing disc induced more mixing action and thus a low value of P. The use of the model with literature data demonstrated that the model was applicable to food and non-food Single-Screw Extrusion process. The applications of different models were also discussed. (C) 1998 Elsevier Science Limited. All rights reserved.

Andrzej Nastaj - One of the best experts on this subject based on the ideXlab platform.

  • Studies on Single-Screw Extrusion of wood-polymer composites with yield stress and slip effects
    PROCEEDINGS OF THE 35TH INTERNATIONAL CONFERENCE OF THE POLYMER PROCESSING SOCIETY (PPS-35), 2020
    Co-Authors: K. Wilczyński, Adrian Lewandowski, Kamila Buziak, Andrzej Nastaj
    Abstract:

    Studies on rheology and processing of wood-polymer composites are very limited in the literature [1]. These are pseudoplastic and viscoelastic materials that exhibit yield stress and wall slipping. Slip effects and flow with yield stress have been investigated numerically for Single Screw Extrusion using ANSYS-Polyflow software. Fully three-dimensional non-Newtonian analysis has been performed both in the extruder (slip on the Screw/barrel surfaces) and in the die. The model of Ostwald-de Waele has been used for flow modeling, the generalized law of Navier has been applied for a slip analysis, and Bingham law has been used for an analysis of the flow with yield stress. An effect of the parameters of these models on the flow in the extruder/die system has been studied. Screw pumping characteristics and die characteristics (i.e. flow rate vs. pressure gradient) have been computed and implemented into the recently developed [2] global model of the Single Screw Extrusion process of wood-polymer composites. This model allows to predict various process parameters, e.g. flow rate, pressure and temperature profiles, melting profile. The effect of slipping and yield stress on the extruder operation, i.e. location of the operating point on the Screw/die characteristics has been discussed.Studies on rheology and processing of wood-polymer composites are very limited in the literature [1]. These are pseudoplastic and viscoelastic materials that exhibit yield stress and wall slipping. Slip effects and flow with yield stress have been investigated numerically for Single Screw Extrusion using ANSYS-Polyflow software. Fully three-dimensional non-Newtonian analysis has been performed both in the extruder (slip on the Screw/barrel surfaces) and in the die. The model of Ostwald-de Waele has been used for flow modeling, the generalized law of Navier has been applied for a slip analysis, and Bingham law has been used for an analysis of the flow with yield stress. An effect of the parameters of these models on the flow in the extruder/die system has been studied. Screw pumping characteristics and die characteristics (i.e. flow rate vs. pressure gradient) have been computed and implemented into the recently developed [2] global model of the Single Screw Extrusion process of wood-polymer composites. Th...

  • Optimization for Starve Fed/Flood Fed Single Screw Extrusion of Polymeric Materials.
    Polymers, 2020
    Co-Authors: Andrzej Nastaj, Krzysztof Wilczynski
    Abstract:

    A novel computer optimization system for flood fed/starve fed Single Screw Extrusion of polymeric materials has been developed. This coupled system allows us to optimize Single Screw Extrusion both flood fed and starve fed. Optimization is based on process simulation which is performed using global Extrusion model GSEM (Global Screw Extrusion Model). The process is optimized with the use of GASEO (Genetic Algorithms Screw Extrusion Optimization) procedures which were developed using Genetic Algorithms. An example of optimization of Extrusion process parameters has been presented to maximize Extrusion output and minimize specific energy consumption. Optimization has been performed in a unique and original way in a coupled manner when both modes of feeding were allowed. The studies have shown that the optimal process is Extrusion with starving. In this case, the global objective function reached the highest value, and Extrusion throughput was relatively high and specific energy consumption was minimal.

  • computer modeling for Single Screw Extrusion of wood plastic composites
    Polymers, 2018
    Co-Authors: Krzysztof Wilczynski, Adrian Lewandowski, Kamila Buziak, Andrzej Nastaj
    Abstract:

    Experimental and theoretical studies have been performed on the Single-Screw Extrusion of wood–plastics composites. Experimental research has been carried out on the flow and melting of polypropylene (PP)-based composites with different wood flour (WF) content in the Single-Screw extruder. Based on these experimental observations, elementary models of the process phenomena have been proposed and a global model of the process has been developed. This global computer model includes the models of solid conveying, melting dependent on the wood flour content, melt flow in the Screw, and melt flow in the die. 3-D non-Newtonian finite element method (FEM) Screw pumping characteristics have been applied to model the melt flow in the metering section of the Screw. The model predicts the Extrusion output, pressure and temperature profiles, melting profile, and power consumption. The model has been validated experimentally. An effect of material slip on the extruder operation has been discussed including both slipping in the Screw/barrel surfaces and in the extruding die.

  • Computer Modeling for Single-Screw Extrusion of Wood⁻Plastic Composites.
    Polymers, 2018
    Co-Authors: Krzysztof Wilczynski, Adrian Lewandowski, Kamila Buziak, Andrzej Nastaj
    Abstract:

    Experimental and theoretical studies have been performed on the Single-Screw Extrusion of wood–plastics composites. Experimental research has been carried out on the flow and melting of polypropylene (PP)-based composites with different wood flour (WF) content in the Single-Screw extruder. Based on these experimental observations, elementary models of the process phenomena have been proposed and a global model of the process has been developed. This global computer model includes the models of solid conveying, melting dependent on the wood flour content, melt flow in the Screw, and melt flow in the die. 3-D non-Newtonian finite element method (FEM) Screw pumping characteristics have been applied to model the melt flow in the metering section of the Screw. The model predicts the Extrusion output, pressure and temperature profiles, melting profile, and power consumption. The model has been validated experimentally. An effect of material slip on the extruder operation has been discussed including both slipping in the Screw/barrel surfaces and in the extruding die.

  • Experimental and theoretical study on starve fed Single Screw Extrusion of polymer blends
    2017
    Co-Authors: K. Wilczyński, Andrzej Nastaj, Adrian Lewandowski, K. Wilczyński
    Abstract:

    An extensive experimental study has been performed for starve fed Single Screw Extrusion of polymer blends. Several materials have been used in the study: LDPE/PS, PP/PS, PP/PMMA, and HDPE/PS blends. “Screw Pulling-out Technique” has been used to study the melting mechanism and flow in the machine. CSM melting mechanism (contiguous solids melting) has been observed for flood fed Extrusion with an obvious presence of minor component inclusions. This mechanism has not been observed for starve fed Extrusion. A new melting mechanism for starve fed Extrusion of polymer blends has been proposed. This includes conductive melting in a partly filled region, and dispersed melting in a fully filled region, and takes into account the solid and molten phases of major and minor components. A forward/backward scheme of computation has been applied for global modeling of the Extrusion process of polymer blends. A modified global SSEM_SF computer model has been applied for simulation of experimental runs.

Adrian Lewandowski - One of the best experts on this subject based on the ideXlab platform.

  • Global Modeling for Single Screw Extrusion of Viscoplastics
    International Polymer Processing, 2020
    Co-Authors: Adrian Lewandowski, Krzysztof Wilczyński
    Abstract:

    Abstract An extensive modeling study is presented on viscoplastic flows in the Single Screw extruder. An effective modeling procedure is developed, and fully three-dimensional Non-Newtonian FEM com...

  • Studies on Single-Screw Extrusion of wood-polymer composites with yield stress and slip effects
    PROCEEDINGS OF THE 35TH INTERNATIONAL CONFERENCE OF THE POLYMER PROCESSING SOCIETY (PPS-35), 2020
    Co-Authors: K. Wilczyński, Adrian Lewandowski, Kamila Buziak, Andrzej Nastaj
    Abstract:

    Studies on rheology and processing of wood-polymer composites are very limited in the literature [1]. These are pseudoplastic and viscoelastic materials that exhibit yield stress and wall slipping. Slip effects and flow with yield stress have been investigated numerically for Single Screw Extrusion using ANSYS-Polyflow software. Fully three-dimensional non-Newtonian analysis has been performed both in the extruder (slip on the Screw/barrel surfaces) and in the die. The model of Ostwald-de Waele has been used for flow modeling, the generalized law of Navier has been applied for a slip analysis, and Bingham law has been used for an analysis of the flow with yield stress. An effect of the parameters of these models on the flow in the extruder/die system has been studied. Screw pumping characteristics and die characteristics (i.e. flow rate vs. pressure gradient) have been computed and implemented into the recently developed [2] global model of the Single Screw Extrusion process of wood-polymer composites. This model allows to predict various process parameters, e.g. flow rate, pressure and temperature profiles, melting profile. The effect of slipping and yield stress on the extruder operation, i.e. location of the operating point on the Screw/die characteristics has been discussed.Studies on rheology and processing of wood-polymer composites are very limited in the literature [1]. These are pseudoplastic and viscoelastic materials that exhibit yield stress and wall slipping. Slip effects and flow with yield stress have been investigated numerically for Single Screw Extrusion using ANSYS-Polyflow software. Fully three-dimensional non-Newtonian analysis has been performed both in the extruder (slip on the Screw/barrel surfaces) and in the die. The model of Ostwald-de Waele has been used for flow modeling, the generalized law of Navier has been applied for a slip analysis, and Bingham law has been used for an analysis of the flow with yield stress. An effect of the parameters of these models on the flow in the extruder/die system has been studied. Screw pumping characteristics and die characteristics (i.e. flow rate vs. pressure gradient) have been computed and implemented into the recently developed [2] global model of the Single Screw Extrusion process of wood-polymer composites. Th...

  • global modeling of Single Screw Extrusion with slip effects
    International Polymer Processing, 2019
    Co-Authors: Adrian Lewandowski, Krzysztof Wilczynski
    Abstract:

    Abstract An extensive study is presented on the polymer melt flow with slip effects in a Single Screw Extrusion process. Fully three-dimensional non-Newtonian FEM computations are performed to desi...

  • computer modeling for Single Screw Extrusion of wood plastic composites
    Polymers, 2018
    Co-Authors: Krzysztof Wilczynski, Adrian Lewandowski, Kamila Buziak, Andrzej Nastaj
    Abstract:

    Experimental and theoretical studies have been performed on the Single-Screw Extrusion of wood–plastics composites. Experimental research has been carried out on the flow and melting of polypropylene (PP)-based composites with different wood flour (WF) content in the Single-Screw extruder. Based on these experimental observations, elementary models of the process phenomena have been proposed and a global model of the process has been developed. This global computer model includes the models of solid conveying, melting dependent on the wood flour content, melt flow in the Screw, and melt flow in the die. 3-D non-Newtonian finite element method (FEM) Screw pumping characteristics have been applied to model the melt flow in the metering section of the Screw. The model predicts the Extrusion output, pressure and temperature profiles, melting profile, and power consumption. The model has been validated experimentally. An effect of material slip on the extruder operation has been discussed including both slipping in the Screw/barrel surfaces and in the extruding die.

  • Computer Modeling for Single-Screw Extrusion of Wood⁻Plastic Composites.
    Polymers, 2018
    Co-Authors: Krzysztof Wilczynski, Adrian Lewandowski, Kamila Buziak, Andrzej Nastaj
    Abstract:

    Experimental and theoretical studies have been performed on the Single-Screw Extrusion of wood–plastics composites. Experimental research has been carried out on the flow and melting of polypropylene (PP)-based composites with different wood flour (WF) content in the Single-Screw extruder. Based on these experimental observations, elementary models of the process phenomena have been proposed and a global model of the process has been developed. This global computer model includes the models of solid conveying, melting dependent on the wood flour content, melt flow in the Screw, and melt flow in the die. 3-D non-Newtonian finite element method (FEM) Screw pumping characteristics have been applied to model the melt flow in the metering section of the Screw. The model predicts the Extrusion output, pressure and temperature profiles, melting profile, and power consumption. The model has been validated experimentally. An effect of material slip on the extruder operation has been discussed including both slipping in the Screw/barrel surfaces and in the extruding die.

A. N.i. Yeh - One of the best experts on this subject based on the ideXlab platform.

  • Starch transitions and their influence on flow pattern during Single-Screw Extrusion cooking of rice flour
    Food and Bioproducts Processing: Transactions of the Institution of of Chemical Engineers Part C, 1999
    Co-Authors: A. N.i. Yeh, Tsai Quen Wu, Yih Mon Jaw
    Abstract:

    The starch transitions and flow pattern of rice flour (40% moisture content) during Single-Screw Extrusion cooking at different temperatures have been investigated. In the first 21.5 cm of the extruder with a cooled barrel, the rice flour remained in powder form and moved easily. The flow of rice flour behaved as a plug flow reactor. At the end of the cooling zone, the swelling of starch granules resulted in a gradual increase in the degree of starch gelatinization which slowed down the flow of materials. Confirmed by the measurements of intrinsic viscosity and gel permeation chromatography (GPC), the degradation of starch molecules occurred simultaneously with the melting of starch granules in the heating zone. Increasing barrel temperature resulted in more starch degradation and longer residence time. The flow pattern was changed from a plug flow reactor to a continuous stirred tank reactor.