In-process measurements for reactive extrusion monitoring and control

Process monitoring of reactive extrusion is often limited to pressure and temperature measurements at the die. These may be sensitive to fluctuations in the process, but provide limited information on the actual characteristics of the polymer system under manufacture. Consequently, in‐process measurement using spectroscopic and rheometric techniques, among others, are used to monitor the manufacture of several reactive systems. This approach helps minimize the time lag associated with collecting and preparing samples for measurements off‐line, may avoid submitting the sampled material to extra thermal cycles that might change its characteristics, and could support new process‐control paradigms. This chapter summarizes the developments of in‐line and on‐line measuring techniques relevant to reactive extrusion and presents some examples of application

Monitoring of polymer extrusion and compounding processes

This work focuses on monitoring of polymer extrusion and melt compounding using single or twin-screw extruders. Standard extruder instrumentation aims at detecting eventual instabilities in flow and heat transfer in the extruder. Strategies for in-process monitoring considering the actual characteristics of the material being processed are presented and discussed. On-line and in-line approaches are defined. The advantages of sampling along the extruder barrel are demonstrated. Examples of the development and application of in-process optical spectroscopy and rheometry techniques are presented and discussed

EURHEO: the Erasmus Mundus Master in Engineering Rheology

EURHEO (www.eurheo.eu) is a two-year Master course delivered under the prestigious Erasmus Mundus programme. EURHEO aims at offering a pioneer advanced education programme on Rheology and its applications to different Engineering areas. It combines the expertise of six leading European Universities in the field of Rheology (University of Minho (UM - Portugal), the University of Ljubljana (ULJ - Slovenia), the Universidad de Huelva (UHU - Spain), the Kaholieke Universiteit Leuven (KUL - Belgium), the Université catholique de Louvain (UCL - Belgium) and the University of Calabria (UCAL - Italy)) and the syllabus is designed to provide students with the necessary competences to understand the relevance of Rheology in Materials Science and Engineering and apply the knowledge gained in solving real-world Engineering problems both autonomously and included in multidisciplinary research teams. We will present the EURHEO education programme, and the types of grants that Portuguese and Spanish students can apply for. The first scientific EURHEO outputs, namely results from selected Master theses, will be presented in 2 posters which report the research carried out by 2 students at UM.European Union and EACEA for granting project 2008-0099-EURHEO: The Erasmus Mundus Master in Engineering Rheology

A scaling-up methodology for co-rotating twin-screw extruders

Scaling-up of co-rotating twin screw extruders is studied as a multi-objective optimization problem where the aim is to define the geometry/operating conditions of the target extruder that minimize the differences between the values of the performance criteria that depict the reference and target extruders. Three computational experiments are discussed. These preliminary results seem encouraging

Use of multi-objective evolutionary algorithms in extrusion scale-up

Extrusion scale-up consists in ensuring identical thermo-mechanical environments in machines of different dimensions, but processing the same material. Given a reference extruder with a certain geometry and operating point, the aim is to define the geometry and operating conditions of a target extruder (of a different magnitude), in order to subject the material being processed to the same flow and heat transfer conditions, thus yielding products with the same characteristics. Scale-up is widely used in industry and academia, for example to extrapolate the results obtained from studies performed in laboratorial machines to the production plant. Since existing scale-up rules are very crude, as they consider a single performance measure and produce unsatisfactory results, this work approaches scale-up as a multi-criteria optimization problem, which seeks to define the geometry/operating conditions of the target extruder that minimize the differences between the values of the criteria for the reference and target extruders. Some case studies are discussed in order to validate the concept

The use of evolutionary algorithms to solve practical problems in polymer extrusion

This work aims at selecting the operating conditions and designing screws that optimize the performance of single-screw and co-rotating twin-screw extruders, which are machines widely used by the polymer processing industry. A special MOEA, denoted as Reduced Pareto Set Genetic Algorithm, RPSGAe, is presented and used to solve these multiobjective combinatorial problems. Twin screw design is formulated as a Travelling Salesman Problem, TSP, given its discrete nature. Various case studies are analyzed and their validity is discussed, thus demonstrating the potential practical usefulness of this approach

Polymer extrusion: setting the operating conditions and defining the screw geometry

(undefined

RPSGAe - Reduced Pareto Set Genetic Algorithm : application to polymer extrusion

Publicado na serie "Lecture notes in economics and mathematical systems" ; 535In this paper a Multiobjective Optimization Genetic Algorithm, denoted as Reduced Pareto Set Genetic Algorithm with Elitism (RPSGAe), is presented and its performance is assessed. The algorithm is compared with other Evolutionary Multi-Objective Algorithms - EMOAs (SPEA2, PAES and NSGA-II) using problems from the literature and statistical comparison techniques. The results obtained showed that the RPSGAe algorithm has good overall performance. Finally, the RPSGAe algorithm was applied to the optimization of the polymer extrusion process. The aim is to implement an automatic optimization scheme capable of defining the values of important process parameters, such as operating conditions and screw geometry, yielding the best performance in terms of prescribed attributes. The results obtained for specific case studies have physical meaning and correspond to a successful process optimization

Modelling of flow and heat transfer, mixing and morphology development in plasticating single screw extrusion of polymer systems

Models for flow and heat transfer, morphology development of liquid-liquid and solids-liquid systems and mixing assessment in conventional single screw estruders are introduced. Their computer implementation and interdependence are explained. Representative predictions are discussed with the aim of illustrating the capability of these models as wells as showing the typical response of single screw extruders