Temperature gradients in the channels of a single-screw extruder

• Published in: Polymer engineering and science Vol. 44; no. 11; pp. 2148 - 2157
• Main Authors: Bur, Anthony J., Roth, Steven C., Spalding, Mark A., Baugh, Daniel W., Koppi, Kurt A., Buzanowski, Walter C.
• Format: Journal Article
• Language: English
• Published: New York Society of Plastics Engineers, Inc 01.11.2004; Wiley Subscription Services; Blackwell Publishing Ltd
• Subjects: Analysis; Applied sciences; Chemical engineering; Chemical processes; Exact sciences and technology; Extruders; Extrusion moulding; Fluorescence; Machinery and processing; Moulding; Plastics; Polycarbonate resins; Polymer industry, paints, wood; Technology of polymers; Temperature; United States; Fluorescent tracer; Process control; Optical sensor; Temperature control; Measurement method; Single screw extruder; Perylene; Experimental study; Polycarbonate; Extrusion molding
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.20221

We used a temperature‐sensitive fluorescent dye, perylene, to monitor the true resin temperature during extrusion of polycarbonate. The measurement involved doping polycarbonate with perylene and detecting fluorescence with an optical sensor that accesses a standard instrumentation port on a barrel of a single‐screw extruder. The sensor's confocal optics design permits fluorescence intensity measurements as a function of position. Using a previously established calibration function, temperature and temperature gradients were obtained from the measured fluorescence. Because the origin of the measurement is the fluorescent dye molecule that is soluble in the resin, this method allows temperature measurement of the polymer without interference from the surrounding metal parts. With the sensor looking over the screw, temperature profiles from the barrel wall to the core of the screw were obtained as a function of screw speed, screw design and resin melt flow rate. Polym. Eng. Sci. 44:2148–2157, 2004. © 2004 Society of Plastics Engineers. This paper is a contribution from the National Institute of Standards and Technology, and, thus, is not subject to copyright in the United States.