Print version ISSN 0104-1428
MELO, Tomás J. A. de; PINHEIRO, Luís A and CANEVAROLO, Sebastião V. Factorial design to quantify the influence of extrusion parameters in the mean residence time. Polímeros [online]. 2010, vol.20, n.4, pp. 322-326. Epub Nov 19, 2010. ISSN 0104-1428. http://dx.doi.org/10.1590/S0104-14282010005000050.
Residence time distribution (RTD) is a very important parameter in extrusion, either for simple polymer processing or for special processes like compounding, blending, reactive compatibilization, and controlled degradation. This work deals with the values of mean residence time (tn) as a function of the number of 45 degrees kneading elements in the screw profile, screw speed, and feeding rate. The tn values were calculated from the RTD curves, which in turn were determined by the technique of a marker added as a pulse in the steady state polymer flow. The values of tn were empirically modeled as a function of those parameters. The results showed that feeding rate is the most influent parameter, followed by number of kneading elements and screw speed. The modeling has given a quadratic function relating tn and the operational parameters tested.
Keywords : Extrusion; residence time distribution; feeding rate; screw profile; factorial design.