Home About us Contact
|
Home About us Contact | ||
|
|
||
In-line Monitoring (in-line + monitoring)
Selected AbstractsIn-Line Monitoring of Vinyl Chloride Suspension Polymerization with Near-Infrared Spectroscopy, 1 , Analysis of Morphological PropertiesMACROMOLECULAR REACTION ENGINEERING, Issue 1 2010Joćo Miguel de Faria Jr. Abstract It is demonstrated that during suspension polymerizations it is possible to monitor morphological characteristics of PVC resins such as bulk density, cold plasticizer absorption and average particle diameter in-line and in real time using NIR spectroscopy. NIR spectra are obtained at different experimental conditions, showing that the spectra are sensitive to changes in the PVC properties. Standard mathematical procedures (partial least squares regression) are used to build empirical models and correlate the morphological properties with the obtained NIR spectra, allowing for monitoring of the PVC morphology in-line and in real time. [source] In-line analysis of a fluid bed pellet coating process using a combination of near infrared and Raman spectroscopyJOURNAL OF CHEMOMETRICS, Issue 7-8 2010Andrey Bogomolov Abstract Near infrared (NIR) and Raman spectroscopic analyzers applied through an immersion Lighthouse Probe (LHP) were used for simultaneous in-line monitoring of a fluid bed pellet coating process. Multivariate curve resolution analysis of data, collected from four pilot-scale batches, has shown that the two techniques deliver complementary information about the process and their combination may be synergistic. This data analysis enabled a much better understanding of some of the process observations and also gave some interesting insights into the best way to use the techniques themselves. PLS regression analysis of the product moisture and the quantity of coating material sprayed was performed using NIR and Raman data blocks both separately and in combination. The performance of method combination compared to individual techniques is analyzed and discussed. Copyright © 2010 John Wiley & Sons, Ltd. [source] IN-LINE CONSISTENCY MONITORING OF TOMATO BASED PRODUCTS USING VIBRATIONAL PROCESS VISCOMETRYJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2001P. J. CULLEN A vibrational process viscometer was evaluated as an in-line consistency monitoring technique for tomato based products. This sensor was installed in both pilot and industry scale production processes. Accuracy of the sensor and its ability to distinguish between varying concentrations of non-Newtonian fluids was evaluated with flowrate and temperature closely controlled. The sensor was shown to have the least inherent variability when compared to off-line techniques. However it was found to be flowrate dependent for the tomato based products. Good correlations between the sensor and off-line techniques were developed for the pilot scale trials. Plant trials revealed a number of problems in developing such correlations under industrial process conditions, however the instrument proved capable of tracking out of specification sauce as determined by the off-line Brookfield viscometer. It was concluded that use of the sensor would result in increased measurement precision over the off-line instruments coupled with the benefits of in-line monitoring. [source] Rapid chemiluminometric determination of gabapentin in pharmaceutical formulations exploiting pulsed-flow analysisLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 1 2009Matķas Manera Abstract In this study, a straightforward and automated pulsed flow-based procedure was developed for the chemiluminometric determination of gabapentin [1-(aminomethyl)cyclo-hexaneacetic acid], a new generation antiepileptic drug, in different formulated dosage forms. The software-controlled time-based injection method capitalizes on the decrease of the background chemiluminescence (CL) readout of the luminol,hypochlorite reaction in the presence of gabapentin. In short, gabapentin works as a hypochlorite scavenger. The analytical procedure was implemented in a multi-pumping flow network furnished with a suite of microdispensing solenoid-actuated pumps. The diaphragm-type micropumps might be configured to operate as fluid propellers, commutation units and metering injectors. A dynamic linear working range for gabapentin concentrations in the range 60,350 µmol/L was obtained, with an estimated detection limit of 40 µmol/L. The flow analyser handles about 41 injections/h and yields precise results (RSD < 2%). The miniaturized flow analyser thus has potential to be exploited for in-line monitoring of drug manufacturing within the quality assurance framework of modern pharmaceutical companies. Copyright © 2008 John Wiley & Sons, Ltd. [source] From Fundamental Polymerization Kinetics to Process Application,A Realistic Vision?,MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 5 2010Christian Bauer Abstract This contribution presents a ramble through the past, inspecting the developments of fundamental scientific investigations into the elementary reaction steps of polymerizations. Often the question arises whether benefits from fundamental scientific investigation find their way into industrial practice and how these pay off in better understanding large-scale processes. The high-pressure ethene polymerization is the system of interest here because 1) it is a complex process with a world production of several million tons per year and 2) although dealing with system pressures up to 3000,bar is not an easy task, a long history,if not tradition,exists between the scientific efforts to improve the process and the research groups of Franck and Buback in Karlsruhe, Schönemann and Luft in Darmstadt, and later Buback in Göttingen. The scope of this discussion will range from non-invasive on- and in-line monitoring by spectroscopic methods up to process modeling by advanced kinetic models and their potential for explorative work. [source] In-line near infrared monitoring of esterification of a molten ethylene,vinyl alcohol copolymer in a twin screw extruderPOLYMER ENGINEERING & SCIENCE, Issue 11 2006Claire Barrčs Near infrared spectroscopy has developed in the polymer industry as a tool for in-line monitoring of processes, particularly extrusion. However, little work is dedicated to the monitoring of chemical reactions involving polymer melts. In this paper, we examine the suitability of NIR spectroscopy for monitoring the chemical modification (catalyzed esterification) of a molten ethylene,vinyl alcohol copolymer by octanoic acid in a twin screw extruder. Extrusion samples are characterized off-line, for calibration purposes, for the three species of interest (i.e. unreacted acid, OH groups, and ester functions formed on the polymer backbone) by means of two techniques: 1H NMR, allowing all three species to be quantified, and residual (free) acid titration. However, the mass balance of free acid is not straightforward, due to loss of mass by volatilization at the vent. Therefore, 1H NMR analysis and acid titration have to be combined to allow for determination of all concentrations. Multivariate calibration is implemented here to quantify and subsequently predict the analyte concentrations by using the NIR spectroscopic data. Our calibration, based on a partial least squares regression software, provides satisfactory results in terms of correlation between actual and predicted concentrations. This work demonstrates the potential of in-line NIR spectroscopy for monitoring chemical reactions with polymer melts in extrusion. POLYM. ENG. SCI. 46:1613,1624, 2006. © 2006 Society of Plastics Engineers [source] Application of ultrasound and neural networks in the determination of filler dispersion during polymer extrusion processesPOLYMER ENGINEERING & SCIENCE, Issue 6 2005Zhigang Sun Mineral filler dispersion is important information for the production of mineral-charged polymers. In order to achieve timely control of product quality, a technique capable of providing real-time information on filler dispersion is highly desirable. In this work, ultrasound, temperature, and pressure sensors as well as an amperemeter of the extruder motor drive were used to monitor the extrusion of mineral-filled polymers under various experimental conditions in terms of filler type, filler concentration, feeding rate, screw rotation speed, and barrel temperature. Then, neural network relationships were established among the filler dispersion index and three categories of variables, namely, control variables of the extruder, extruder-dependent measured variables, and extruder-independent measured variables (based on ultrasonic measurement). Of the three categories of variables, the process control variables and extruder-independent ultrasonically measured variables performed best in inferring the dispersion index through a neural network model. While the neural network model based on control variables could help determine the optimal experimental conditions to achieve a dispersion index, the extruder-independent network model based on ultrasonic measurement is suitable for in-line measurement of the quality of dispersion. This study has demonstrated the feasibility of using ultrasound and neural networks for in-line monitoring of dispersion during extrusion processes of mineral-charged polymers. POLYM. ENG. SCI., 45:764,772, 2005. © 2005 Society of Plastics Engineers [source] | |||||||||||||