This study is concerned with the flow behaviour of a rubber compound in capillary and injection moulding dies in the temperature range of 80–120°C. The injection moulding die designs had a tapered angle ranging from 40° up to 150°. The rheological characterisation of the rubber compound in the capillary dies showed that rubber slips at the wall, and this was modelled with an appropriate slip law. The pressure drops in the system were measured for all tapered dies. Numerical simulations were then carried out with a purely viscous (Carreau) model and a multimode viscoelastic (K-BKZ) model. The results showed a good agreement with the experiments for both the capillary and the injection moulding dies, provided that slip is included in the simulations as determined experimentally.
PerkoL, FaschingM, FriesenbichlerW.Model for the prediction of bulk temperature changes and pressure losses in rubber compounds flowing through conical dies: an engineering approach. Polym Eng Sci. 2015;55:701–709. doi: 10.1002/pen.23931
2.
PerkoL, FriesenbichlerW. Reduction of cure time in elastomer processing. Rubber Fibres Plast Int. 2015;10:117–121.
3.
DealyJM, WissbrunKF. Melt rhelolgy and its role in plastics processing – theory and applications. New York: Van Nostrand Reinhold; 1990.
4.
LaunHM. Pressure dependent viscosity and dissipative heating in capillary rheometry of polymer melts. Rheol Acta. 2003;42:295–308. doi: 10.1007/s00397-002-0291-6
TannerRI. Engineering rheology. 2nd ed.Oxford: Oxford University Press; 2000.
15.
MitsoulisE.Chapter 4. Computational polymer processing. In: GujratiPD, LeonovAI, editors. Modeling and simulation in polymers. Weinheim, Germany: Wiley-VCH Verlag; 2010. p. 127–195.
16.
DealyJM, LarsonRG. Structure and rheology of molten polymers – from structure to flow behavior and back again. Munich: Hanser; 2006.
17.
PapanastasiouAC, ScrivenLE, MacoskoCW. An integral constitutive equation for mixed flows: viscoelastic characterization. J Rheol.1983;27:387–410. doi: 10.1122/1.549712
18.
LuoXL, TannerRI. Finite element simulation of long and short circular die extrusion experiments using integral models. Int J Num Meth Eng. 1988;25:9–22. doi: 10.1002/nme.1620250104
19.
KajiwaraT, BarakosG, MitsoulisE. Rheological characterization of polymer solutions and melts with an integral constitutive equation. Int J Polym Anal Charact. 1995;1:201–215. doi: 10.1080/10236669508233875
20.
LuoXL, TannerRI. A pseudo-time integral method for non-isothermal viscoelastic flows and its application to extrusion simulation. Rheol Acta. 1987;26:499–507. doi: 10.1007/BF01333733
21.
BarakosG, MitsoulisE. Non-isothermal viscoelastic simulations of extrusion through dies and prediction of the bending phenomenon. J Non-Newton Fluid Mech.1996;62:55–79.
22.
HatzikiriakosSG, DealyJM. Wall slip of molten high density polyethylene I. Sliding plate rheometer studies. J Rheol.1991;35:497–523. doi: 10.1122/1.550178
23.
HatzikiriakosSG, DealyJM. Wall slip of molten high density polyethylene. II. Capillary rheometer studies. J Rheol. 1992;36:703–741. doi: 10.1122/1.550313
24.
MitsoulisE, KazatchkovIB, HatzikiriakosSG. The effect of slip in the flow of a branched PP polymer: experiments and simulations. Rheol Acta. 2005;44:418–426. doi: 10.1007/s00397-004-0423-2
25.
MitsoulisE, HatzikiriakosSG. Steady flow simulations of compressible PTFE paste extrusion under severe wall slip. J Non-Newton Fluid Mech. 2009;157:26–33. doi: 10.1016/j.jnnfm.2008.09.003
26.
HannachiA, MitsoulisE. Sheet coextrusion of polymer solutions and melts: comparison between simulation and experiments. Adv Polym Technol. 1993;12:217–231. doi: 10.1002/adv.1993.060120301
27.
LuoXL, MitsoulisE. An efficient algorithm for strain history tracking in finite element computations of non-Newtonian fluids with integral constitutive equations. Int J Num Meth Fluids. 1990;11:1015–1031. doi: 10.1002/fld.1650110708
28.
AnsariM, AlabbasA, MitsoulisE, Entry flows of polyethylene melts in tapered dies. Intern Polym Proc. 2010;25:287–296. doi: 10.3139/217.2360
