An inline rheometer is described for determination of an engineering extensional viscosity using pressure drops in conical converging flow under fixed extruder processing conditions. A ‘temperature cross' with 16 thermocouples is incorporated for detailed measurement of the temperature of melt passing to the rheometer. Temperature variations are taken into account in extracting extensional viscosity values using a modified version of the analysis by Binding. Results are reported for a profile grade uPVC. The applicability of the Binding analysis in this case is examined and confirmed. Results compare well with published data for profile grade uPVC, taking into account differences in formulation.
DebbautB. and CrochetM. J.: J. Non-Newtonian Fluid Mech., 1988, 30, 169.
10.
MetznerA. B., UeblerE. A. and ChanC. F.: AIChEJ, 1969, 15, 150.
11.
MetznerA. B. and MetznerA. P.: Rhea Acta, 1970, 9, 174.
12.
MetznerA. B.: RheoL Acta, 1972, 10, 434.
13.
HiirlimannH. P. and KnappeW.: Rhea Acta, 1972, 11, 292.
14.
BalakrishnanC. and GordonR. J.: AIChEJ, 1975, 21, 1225.
15.
CogswellF. N.: Trans. Soc. Rheol., 1972, 16, 383.
16.
CogswellF. N.: Poly. Eng. Sci., 1972, 12, 64.
17.
BindingD. M.: J. Non-Newtonian Fluid Mech., 1988, 27, 173.
18.
BindingD. M.: J. Non-Newtonian Fluid Mech., 1991, 41, 27.
19.
BerstedB. H.: Poly. Eng. Sci., 1993, 33, 1079.
20.
PadmanabhanM. and MacoskoC.: RheoL Acta, 1997, 36, 144.
21.
MackayM. E. and AstaritaG.: J. Non-Newtonian Fluid Mech., 1997, 70, 219.
22.
EttingerH., HaaseR., PittmanJ. F. T. and SienzJ.: Proc. 21st PPS Ann. Conf., Leipzig, Germany, 2005, The Polymer Processing Society, paper 61.
23.
PittmanJ. F. T. and MahmoudzadehH.: Poly. Eng. Rev., 1983, 3, 75.
24.
CogswellF. N.: J. Non-Newtonian Fluid Mech., 1978, 4, 23.
25.
CoatesP. D., KellyA. L., RoseR. M. and WoodheadM.: ‘In-process entry pressure measurements in extrusion and injection moulding’, Polymer Insights Series;1998, IRC in Polymer Science and Technology, University of Bradford.
