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E. C. Brown - One of the best experts on this subject based on the ideXlab platform.
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the effect of materials process settings and screw geometry on energy consumption and Melt Temperature in single screw extrusion
Applied Energy, 2016Co-Authors: Chamil Abeykoon, E. C. Brown, Adrian L. Kelly, Philip D. CoatesAbstract:Polymer extrusion is an energy intensive production process and process energy efficiency has become a key concern in the current industry with the pressure of reducing the global carbon footprint. Here, knowledge of the pattern of energy usage and losses of each component in the plant is highly useful in the process energy optimization. Moreover, it is essential to maintain the Melt quality while improving the energy efficiency in polymer processing. In this work, an investigation was made on the total energy consumption, drive motor energy consumption, power factor and the Melt Temperature profile across the die Melt flow (as an indication of the Melt thermal quality) of an industrial scale extruder with three different screw geometries, three polymer types and wide range of processing conditions (altogether 135 different processing situations were observed). This aims to widen the knowledge on process energy and thermal behaviors while exploring possible correlation/s between energy demand and Melt quality (in terms of Melt Temperature fluctuations across the Melt flow). The results showed that the level and fluctuations of the extruder’s power factor is particularly dependent upon the material being processed. Moreover, it seems that there is a relation between the level of energy demand of the heaters and the level of Melt Temperature fluctuations. While the extruder specific energy consumption decreases with increasing screw speed, specific energy consumption of the drive motor may have either increasing or decreasing behavior. Overall, this study provides new insights in a wide range on process energy demand and Melt thermal quality in polymer extrusion. Moreover, further research is recommended to establish strong correlation/s between process energy consumption and Melt thermal quality which should help to enhance process control and hence the product quality in single screw polymer extrusion.
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infrared Melt Temperature measurement of single screw extrusion
Polymer Engineering and Science, 2015Co-Authors: Javier Verasorroche, Adrian L. Kelly, E. C. Brown, Philip D. CoatesAbstract:An infrared Temperature sensor has been used to provide real time quantification of the thermal homogeneity of polymer extrusion. The non-intrusive sensor was located in the barrel of a single screw extruder, positioned such that it provided a measurement of Melt Temperature in the channel of the metering section of the extruder screw. The rapid response of the technique enabled Melt Temperature within the extruder screw channel to be monitored in real time, allowing quantification of the thermal stability of the extrusion process. Two polyethylenes were used in experiments with three extruder screw geometries at a range of screw speeds. Data generated by the infrared sensor was found to be highly sensitive to thermal fluctuations relating to the Melting performance of the extruder screw. Comparisons made with an intrusive thermocouple grid sensor located in the extruder die suggested that the infrared technique was able to provide a similar level of information without disturbing the process flow. This application on infrared thermometry could prove highly useful for industrial extrusion process monitoring and optimization. POLYM. ENG. SCI., 55:1059–1066, 2015. © 2014 The Authors. Polymer Engineering & Science published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers
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a review and evaluation of Melt Temperature sensors for polymer extrusion
Sensors and Actuators A-physical, 2012Co-Authors: Chamil Abeykoon, Adrian L. Kelly, Peter Martin, E. C. BrownAbstract:Abstract Melt Temperature is one of the key variables in polymer extrusion which determines process thermal stability and hence Melt quality. Therefore, Melt Temperature is commonly measured in polymer processing and point/bulk Melt Temperature measurement methods are widely used in the present industry. Some thermal profile measurement methods have also been attempted in research. This study presents a review of Melt Temperature measurements in polymer extrusion in research and industry, and describes the results of an experimental evaluation carried out to explore the performance of five Melt Temperature measurement techniques. In addition, an investigation was carried out on the fully developed Melt Temperature profile of a cylindrical rod die. Moreover, the existing challenges and possible future applications for extrusion thermal monitoring are discussed. The results confirmed that Melt Temperature varied significantly at different radial locations within the die. Point/bulk Melt Temperature measurements were found to provide relatively limited information on process thermal quality close to the die wall. Hence, information provided by these sensors is less representative of actual thermal conditions as they are unable to capture thermal information from the whole Melt flow cross-section. Therefore, the importance of the development of industrially compatible thermal profile measurement techniques is emphasised.
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Melt Temperature field measurements in extrusion using thermocouple meshes
Plastics Rubber and Composites, 2008Co-Authors: Adrian L. Kelly, E. C. Brown, K. Howell, Philip D. CoatesAbstract:AbstractThermocouple grids have been shown to provide a unique insight into Melt Temperature fields and their time dependent behaviour in extruders. These systems have been extended from single axis designs to larger arrays for more detailed Temperature measurements. Nine junction (3 × 3) arrays have provided a map of the Temperature profile across the Melt, and the technique has been used to assess the effect of extrusion conditions such as polymer type, screw geometry and Melt pressure. The data are proving invaluable for extruder screw design and to inform more accurate computer modelling of polymer Melt flows. Single axis grids have also been applied to twin screw compounding extrusion, and the results showed a significant amount of shear heating with the hottest points being along the centre line of the two screws.
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The effect of screw geometry on Melt Temperature profile in single screw extrusion.
Polymer Engineering and Science, 2006Co-Authors: Adrian L. Kelly, E. C. Brown, Philip D. CoatesAbstract:Experimental observations of Melt Temperature profiles and Melting performance of extruder screws are reported. A novel Temperature sensor consisting of a grid of thermocouple junctions was used to take multiple Temperature readings in real time across Melt flow in a single screw extruder. Melt pressure in the die and power consumption were also monitored. Three extruder screws at a range of screw speeds were examined for a commercial grade of low density polyethylene. Results showed Melt Temperature fields at low throughputs to be relatively independent of screw geometry with a flat-shaped Temperature profile dominated by conduction. At high throughputs, Melting performance and measured Temperature fields were highly dependent upon screw geometry. A barrier-flighted screw with Maddock mixer achieved significantly better Melting than single flighted screws. Low Temperature “shoulder” regions were observed in the Temperature profiles of single-flighted screws at high throughput, due to late Melting of the solid bed. Stability of the Melt flow was also dependent upon screw geometry and the barrier-flighted screw achieving flow with lower variation in Melt pressure and Temperature. Dimensionless numbers were used to analyze the relative importance of conduction, convection, and viscous shear to the state of the Melt at a range of extrusion conditions. Polym. Eng. Sci. 46:1706–1714, 2006. © 2006 Society of Plastics Engineers
Adrian L. Kelly - One of the best experts on this subject based on the ideXlab platform.
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the effect of materials process settings and screw geometry on energy consumption and Melt Temperature in single screw extrusion
Applied Energy, 2016Co-Authors: Chamil Abeykoon, E. C. Brown, Adrian L. Kelly, Philip D. CoatesAbstract:Polymer extrusion is an energy intensive production process and process energy efficiency has become a key concern in the current industry with the pressure of reducing the global carbon footprint. Here, knowledge of the pattern of energy usage and losses of each component in the plant is highly useful in the process energy optimization. Moreover, it is essential to maintain the Melt quality while improving the energy efficiency in polymer processing. In this work, an investigation was made on the total energy consumption, drive motor energy consumption, power factor and the Melt Temperature profile across the die Melt flow (as an indication of the Melt thermal quality) of an industrial scale extruder with three different screw geometries, three polymer types and wide range of processing conditions (altogether 135 different processing situations were observed). This aims to widen the knowledge on process energy and thermal behaviors while exploring possible correlation/s between energy demand and Melt quality (in terms of Melt Temperature fluctuations across the Melt flow). The results showed that the level and fluctuations of the extruder’s power factor is particularly dependent upon the material being processed. Moreover, it seems that there is a relation between the level of energy demand of the heaters and the level of Melt Temperature fluctuations. While the extruder specific energy consumption decreases with increasing screw speed, specific energy consumption of the drive motor may have either increasing or decreasing behavior. Overall, this study provides new insights in a wide range on process energy demand and Melt thermal quality in polymer extrusion. Moreover, further research is recommended to establish strong correlation/s between process energy consumption and Melt thermal quality which should help to enhance process control and hence the product quality in single screw polymer extrusion.
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infrared Melt Temperature measurement of single screw extrusion
Polymer Engineering and Science, 2015Co-Authors: Javier Verasorroche, Adrian L. Kelly, E. C. Brown, Philip D. CoatesAbstract:An infrared Temperature sensor has been used to provide real time quantification of the thermal homogeneity of polymer extrusion. The non-intrusive sensor was located in the barrel of a single screw extruder, positioned such that it provided a measurement of Melt Temperature in the channel of the metering section of the extruder screw. The rapid response of the technique enabled Melt Temperature within the extruder screw channel to be monitored in real time, allowing quantification of the thermal stability of the extrusion process. Two polyethylenes were used in experiments with three extruder screw geometries at a range of screw speeds. Data generated by the infrared sensor was found to be highly sensitive to thermal fluctuations relating to the Melting performance of the extruder screw. Comparisons made with an intrusive thermocouple grid sensor located in the extruder die suggested that the infrared technique was able to provide a similar level of information without disturbing the process flow. This application on infrared thermometry could prove highly useful for industrial extrusion process monitoring and optimization. POLYM. ENG. SCI., 55:1059–1066, 2015. © 2014 The Authors. Polymer Engineering & Science published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers
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Dynamic modelling of die Melt Temperature profile in polymer extrusion: Effects of process settings, screw geometry and material
Applied Mathematical Modelling, 2014Co-Authors: Chamil Abeykoon, Peter Martin, Adrian L. KellyAbstract:Abstract Extrusion is one of the major methods for processing polymeric materials and the thermal homogeneity of the process output is a major concern for manufacture of high quality extruded products. Therefore, accurate process thermal monitoring and control are important for product quality control. However, most industrial extruders use single point thermocouples for the Temperature monitoring/control although their measurements are highly affected by the barrel metal wall Temperature. Currently, no industrially established thermal profile measurement technique is available. Furthermore, it has been shown that the Melt Temperature changes considerably with the die radial position and hence point/bulk measurements are not sufficient for monitoring and control of the Temperature across the Melt flow. The majority of process thermal control methods are based on linear models which are not capable of dealing with process nonlinearities. In this work, the die Melt Temperature profile of a single screw extruder was monitored by a thermocouple mesh technique. The data obtained was used to develop a novel approach of modelling the extruder die Melt Temperature profile under dynamic conditions (i.e. for predicting the die Melt Temperature profile in real-time). These newly proposed models were in good agreement with the measured unseen data. They were then used to explore the effects of process settings, material and screw geometry on the die Melt Temperature profile. The results showed that the process thermal homogeneity was affected in a complex manner by changing the process settings, screw geometry and material.
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CDC - Dynamic modelling of die Melt Temperature profile in polymer extrusion
52nd IEEE Conference on Decision and Control, 2013Co-Authors: Chamil Abeykoon, Adrian L. Kelly, Peter MartinAbstract:The extrusion process is one of the main methods of processing polymeric materials and thermal homogeneity of the process output presents a major challenge for high quality extruded products. Therefore, accurate process thermal monitoring and control are highly desirable. However, most of the industrial extruders use conventional single point thermocouples for thermal monitoring although their measurements are highly affected by barrel metal wall Temperature. Moreover, it has been shown that the Melt Temperature changes considerably with the die radial position and point based measurements are not sufficient to determine the actual process thermal stability and hence to control the thermal homogeneity of Melt output. Conversely, the majority of process thermal control methods are based on linear models and are not capable of dealing with process nonlinearities. In this work, a die Melt Temperature profile was monitored by a thermocouple mesh technique and the data obtained was used to formulate a new nonlinear dynamic model to predict the die Melt Temperature profile in a single screw extruder. The model is in good agreement with the measured data and offers a promising thermal monitoring technique which can be used in real-time for a thermal profile based control framework in polymer extrusion.
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a review and evaluation of Melt Temperature sensors for polymer extrusion
Sensors and Actuators A-physical, 2012Co-Authors: Chamil Abeykoon, Adrian L. Kelly, Peter Martin, E. C. BrownAbstract:Abstract Melt Temperature is one of the key variables in polymer extrusion which determines process thermal stability and hence Melt quality. Therefore, Melt Temperature is commonly measured in polymer processing and point/bulk Melt Temperature measurement methods are widely used in the present industry. Some thermal profile measurement methods have also been attempted in research. This study presents a review of Melt Temperature measurements in polymer extrusion in research and industry, and describes the results of an experimental evaluation carried out to explore the performance of five Melt Temperature measurement techniques. In addition, an investigation was carried out on the fully developed Melt Temperature profile of a cylindrical rod die. Moreover, the existing challenges and possible future applications for extrusion thermal monitoring are discussed. The results confirmed that Melt Temperature varied significantly at different radial locations within the die. Point/bulk Melt Temperature measurements were found to provide relatively limited information on process thermal quality close to the die wall. Hence, information provided by these sensors is less representative of actual thermal conditions as they are unable to capture thermal information from the whole Melt flow cross-section. Therefore, the importance of the development of industrially compatible thermal profile measurement techniques is emphasised.
Chamil Abeykoon - One of the best experts on this subject based on the ideXlab platform.
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the effect of materials process settings and screw geometry on energy consumption and Melt Temperature in single screw extrusion
Applied Energy, 2016Co-Authors: Chamil Abeykoon, E. C. Brown, Adrian L. Kelly, Philip D. CoatesAbstract:Polymer extrusion is an energy intensive production process and process energy efficiency has become a key concern in the current industry with the pressure of reducing the global carbon footprint. Here, knowledge of the pattern of energy usage and losses of each component in the plant is highly useful in the process energy optimization. Moreover, it is essential to maintain the Melt quality while improving the energy efficiency in polymer processing. In this work, an investigation was made on the total energy consumption, drive motor energy consumption, power factor and the Melt Temperature profile across the die Melt flow (as an indication of the Melt thermal quality) of an industrial scale extruder with three different screw geometries, three polymer types and wide range of processing conditions (altogether 135 different processing situations were observed). This aims to widen the knowledge on process energy and thermal behaviors while exploring possible correlation/s between energy demand and Melt quality (in terms of Melt Temperature fluctuations across the Melt flow). The results showed that the level and fluctuations of the extruder’s power factor is particularly dependent upon the material being processed. Moreover, it seems that there is a relation between the level of energy demand of the heaters and the level of Melt Temperature fluctuations. While the extruder specific energy consumption decreases with increasing screw speed, specific energy consumption of the drive motor may have either increasing or decreasing behavior. Overall, this study provides new insights in a wide range on process energy demand and Melt thermal quality in polymer extrusion. Moreover, further research is recommended to establish strong correlation/s between process energy consumption and Melt thermal quality which should help to enhance process control and hence the product quality in single screw polymer extrusion.
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ECC - Soft sensing of Melt Temperature in polymer extrusion
2016 European Control Conference (ECC), 2016Co-Authors: Chamil AbeykoonAbstract:Precise monitoring techniques are invaluable to any process for diagnosing its operational health, safety concerns and also for achieving good process control. In polymer extrusion, it is quite difficult to visually observe the Melt inside barrel during the process operation and hence the level of control of the process operational quality is highly dependent upon the process monitoring techniques. Currently, a number of physical sensing devices are widely available in industry for monitoring of parameters such as Melt Temperature, Melt pressure, screw speed and so forth. However, there are some limitations to use physical sensors in process measurements due to several constraints such as their access requirements, disruptive effects on the Melt flow, fragility, complexity, etc. Thus, the application of soft sensing techniques should be highly useful for improved process monitoring and hence for advanced process control. In this work, a general discussion is made on the soft sensors and soft sensing applications in polymer extrusion. Then, a soft sensor concept is proposed for the die Melt Temperature profile prediction in polymer extrusion. The simulation results showed that the proposed technique can predict the Temperature profile across the Melt flow in real-time with good accuracy. Eventually, the importance of developing of such soft sensing techniques is discussed while providing some of the possible directions for future research.
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Extruder Melt Temperature Control With Fuzzy Logic
IFAC Proceedings Volumes, 2016Co-Authors: Chamil Abeykoon, Peter Martin, Marion Mcafee, George W. IrwinAbstract:Abstract In polymer extrusion, the delivery of a Melt which is homogenous in composition and Temperature is paramount for achieving high quality extruded products. However, advancements in process control are required to reduce Temperature variations across the Melt flow which can result in poor product quality. The majority of thermal monitoring methods provide only low accuracy point/bulk Melt Temperature measurements and cause poor controller performance. Furthermore, the most common conventional proportional-integral-derivative controllers seem to be incapable of performing well over the nonlinear operating region. This paper presents a model-based fuzzy control approach to reduce the die Melt Temperature variations across the Melt flow while achieving desired average die Melt Temperature. Simulation results confirm the efficacy of the proposed controller.
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Dynamic modelling of die Melt Temperature profile in polymer extrusion: Effects of process settings, screw geometry and material
Applied Mathematical Modelling, 2014Co-Authors: Chamil Abeykoon, Peter Martin, Adrian L. KellyAbstract:Abstract Extrusion is one of the major methods for processing polymeric materials and the thermal homogeneity of the process output is a major concern for manufacture of high quality extruded products. Therefore, accurate process thermal monitoring and control are important for product quality control. However, most industrial extruders use single point thermocouples for the Temperature monitoring/control although their measurements are highly affected by the barrel metal wall Temperature. Currently, no industrially established thermal profile measurement technique is available. Furthermore, it has been shown that the Melt Temperature changes considerably with the die radial position and hence point/bulk measurements are not sufficient for monitoring and control of the Temperature across the Melt flow. The majority of process thermal control methods are based on linear models which are not capable of dealing with process nonlinearities. In this work, the die Melt Temperature profile of a single screw extruder was monitored by a thermocouple mesh technique. The data obtained was used to develop a novel approach of modelling the extruder die Melt Temperature profile under dynamic conditions (i.e. for predicting the die Melt Temperature profile in real-time). These newly proposed models were in good agreement with the measured unseen data. They were then used to explore the effects of process settings, material and screw geometry on the die Melt Temperature profile. The results showed that the process thermal homogeneity was affected in a complex manner by changing the process settings, screw geometry and material.
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A Novel Soft Sensor for Real-Time Monitoring of the Die Melt Temperature Profile in Polymer Extrusion
IEEE Transactions on Industrial Electronics, 2014Co-Authors: Chamil AbeykoonAbstract:Polymer extrusion is the most fundamental technique for processing polymeric materials, and its importance is increasing due to the rapid growth of worldwide demand for polymeric materials. However, the process thermal monitoring is experiencing several problems resulting in poor process diagnostics and control. Most of the existing process thermal monitoring methods in industry only provide point/bulk measurements, which are less detailed and low in accuracy. Physical thermal profile measurements across the Melt flow may not be industrially compatible due to their complexity, access requirements, invasiveness, etc. Therefore, inferential thermal profile monitoring techniques are invaluable for obtaining detailed, accurate, and industrially compatible measurements and, hence, to achieve improved process control. In this paper, a novel soft sensor strategy is proposed to predict the real-time Temperature profile across the die Melt flow in polymer extrusion for the first time in industry or research. It is capable of determining the Melt Temperature at a number of die radial positions only based on six readily measurable process parameters. A comparison between the simulation results of the novel Melt Temperature profile prediction soft sensor and the experimental measurements showed that the soft sensor can predict the real-time Melt Temperature profile of the die Melt flow with good accuracy. Therefore, this will offer a promising solution for making real-time Melt Temperature profile measurements noninvasively in polymer extrusion, and also, it should be applicable to other polymer processes only with a few modifications. Moreover, this technique should facilitate in developing an advanced process thermal control strategy.
Philip D. Coates - One of the best experts on this subject based on the ideXlab platform.
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the effect of materials process settings and screw geometry on energy consumption and Melt Temperature in single screw extrusion
Applied Energy, 2016Co-Authors: Chamil Abeykoon, E. C. Brown, Adrian L. Kelly, Philip D. CoatesAbstract:Polymer extrusion is an energy intensive production process and process energy efficiency has become a key concern in the current industry with the pressure of reducing the global carbon footprint. Here, knowledge of the pattern of energy usage and losses of each component in the plant is highly useful in the process energy optimization. Moreover, it is essential to maintain the Melt quality while improving the energy efficiency in polymer processing. In this work, an investigation was made on the total energy consumption, drive motor energy consumption, power factor and the Melt Temperature profile across the die Melt flow (as an indication of the Melt thermal quality) of an industrial scale extruder with three different screw geometries, three polymer types and wide range of processing conditions (altogether 135 different processing situations were observed). This aims to widen the knowledge on process energy and thermal behaviors while exploring possible correlation/s between energy demand and Melt quality (in terms of Melt Temperature fluctuations across the Melt flow). The results showed that the level and fluctuations of the extruder’s power factor is particularly dependent upon the material being processed. Moreover, it seems that there is a relation between the level of energy demand of the heaters and the level of Melt Temperature fluctuations. While the extruder specific energy consumption decreases with increasing screw speed, specific energy consumption of the drive motor may have either increasing or decreasing behavior. Overall, this study provides new insights in a wide range on process energy demand and Melt thermal quality in polymer extrusion. Moreover, further research is recommended to establish strong correlation/s between process energy consumption and Melt thermal quality which should help to enhance process control and hence the product quality in single screw polymer extrusion.
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infrared Melt Temperature measurement of single screw extrusion
Polymer Engineering and Science, 2015Co-Authors: Javier Verasorroche, Adrian L. Kelly, E. C. Brown, Philip D. CoatesAbstract:An infrared Temperature sensor has been used to provide real time quantification of the thermal homogeneity of polymer extrusion. The non-intrusive sensor was located in the barrel of a single screw extruder, positioned such that it provided a measurement of Melt Temperature in the channel of the metering section of the extruder screw. The rapid response of the technique enabled Melt Temperature within the extruder screw channel to be monitored in real time, allowing quantification of the thermal stability of the extrusion process. Two polyethylenes were used in experiments with three extruder screw geometries at a range of screw speeds. Data generated by the infrared sensor was found to be highly sensitive to thermal fluctuations relating to the Melting performance of the extruder screw. Comparisons made with an intrusive thermocouple grid sensor located in the extruder die suggested that the infrared technique was able to provide a similar level of information without disturbing the process flow. This application on infrared thermometry could prove highly useful for industrial extrusion process monitoring and optimization. POLYM. ENG. SCI., 55:1059–1066, 2015. © 2014 The Authors. Polymer Engineering & Science published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers
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Melt Temperature field measurements in extrusion using thermocouple meshes
Plastics Rubber and Composites, 2008Co-Authors: Adrian L. Kelly, E. C. Brown, K. Howell, Philip D. CoatesAbstract:AbstractThermocouple grids have been shown to provide a unique insight into Melt Temperature fields and their time dependent behaviour in extruders. These systems have been extended from single axis designs to larger arrays for more detailed Temperature measurements. Nine junction (3 × 3) arrays have provided a map of the Temperature profile across the Melt, and the technique has been used to assess the effect of extrusion conditions such as polymer type, screw geometry and Melt pressure. The data are proving invaluable for extruder screw design and to inform more accurate computer modelling of polymer Melt flows. Single axis grids have also been applied to twin screw compounding extrusion, and the results showed a significant amount of shear heating with the hottest points being along the centre line of the two screws.
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The effect of screw geometry on Melt Temperature profile in single screw extrusion.
Polymer Engineering and Science, 2006Co-Authors: Adrian L. Kelly, E. C. Brown, Philip D. CoatesAbstract:Experimental observations of Melt Temperature profiles and Melting performance of extruder screws are reported. A novel Temperature sensor consisting of a grid of thermocouple junctions was used to take multiple Temperature readings in real time across Melt flow in a single screw extruder. Melt pressure in the die and power consumption were also monitored. Three extruder screws at a range of screw speeds were examined for a commercial grade of low density polyethylene. Results showed Melt Temperature fields at low throughputs to be relatively independent of screw geometry with a flat-shaped Temperature profile dominated by conduction. At high throughputs, Melting performance and measured Temperature fields were highly dependent upon screw geometry. A barrier-flighted screw with Maddock mixer achieved significantly better Melting than single flighted screws. Low Temperature “shoulder” regions were observed in the Temperature profiles of single-flighted screws at high throughput, due to late Melting of the solid bed. Stability of the Melt flow was also dependent upon screw geometry and the barrier-flighted screw achieving flow with lower variation in Melt pressure and Temperature. Dimensionless numbers were used to analyze the relative importance of conduction, convection, and viscous shear to the state of the Melt at a range of extrusion conditions. Polym. Eng. Sci. 46:1706–1714, 2006. © 2006 Society of Plastics Engineers
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Melt Temperature field measurement: influence of extruder screw and die geometry
Plastics Rubber and Composites, 2005Co-Authors: Adrian L. Kelly, E. C. Brown, Philip D. CoatesAbstract:Melt Temperature fields have been measured in single screw extrusion using novel thermocouple grid, ultrasound and infrared sensor techniques. The effects of screw and die geometry on the Melt Temperature profile have been investigated using simple slit and rod dies on a single screw extruder. Comparisons have been made between a general purpose polyolefin screw with gradual Melting zone, a rapid transition screw, and a barrier flighted screw with a Maddock mixer. Significant differences in Melting and Temperature profiles were observed between the three extruder screws. Die geometry of the simple dies studied here was found to have a minor effect on the Melt Temperature field in regions near the die wall. Die head pressure had a more significant effect on Melt Temperature distribution.
Amauri Garcia - One of the best experts on this subject based on the ideXlab platform.
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The effect of Melt Temperature profile on the transient metal/mold heat transfer coefficient during solidification
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Ivaldo L. Ferreira, José E. Spinelli, Jose Carlos Dos Santos Pires, Amauri GarciaAbstract:Modeling of casting solidification can provide a method for improving casting yields. An accurate casting solidification model might be used to predict microstructure and to control the process based on thermal and operational parameters, and for this, it is necessary the previous knowledge of the transient metal/mold heat transfer coefficient, hi. Most investigations concerning the overall heat transfer coefficient between metal and mold have applied numerical methods for the solution of the inverse heat conduction problem (IHCP). In general, such studies consider a constant initial Melt Temperature in order to reckon the time-dependent hi. In the present work, solidification experiments have been carried with alloys of two metallic systems, and experimentally obtained Temperatures were used by a numerical technique in order to determine transient metal/mold heat transfer coefficients, hi. It is shown that hi profiles can be affected significantly by the initial Melt Temperature distribution. © 2005 Elsevier B.V. All rights reserved.
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the effect of Melt Temperature profile on the transient metal mold heat transfer coefficient during solidification
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Ivaldo L. Ferreira, José E. Spinelli, Jose Carlos Santos Pires, Amauri GarciaAbstract:Modeling of casting solidification can provide a method for improving casting yields. An accurate casting solidification model might be used to predict microstructure and to control the process based on thermal and operational parameters, and for this, it is necessary the previous knowledge of the transient metal/mold heat transfer coefficient, hi. Most investigations concerning the overall heat transfer coefficient between metal and mold have applied numerical methods for the solution of the inverse heat conduction problem (IHCP). In general, such studies consider a constant initial Melt Temperature in order to reckon the time-dependent hi. In the present work, solidification experiments have been carried with alloys of two metallic systems, and experimentally obtained Temperatures were used by a numerical technique in order to determine transient metal/mold heat transfer coefficients, hi. It is shown that hi profiles can be affected significantly by the initial Melt Temperature distribution. © 2005 Elsevier B.V. All rights reserved.