Abstract
In a previous paper, novel numerical method for solving the equations governing the unsteady-state melt spinning process was reported. The method based on orthogonal collocation was found to be very suitable in numerically solving nonlinear differential equations.
In this paper we discuss the simulation of draw resonance in unsteady melt spinning process which are described by nonlinear partial differential equations. Both isothermal and non isothermal conditions were simulated, and in the latter case results were compared with experimental data.
Following results were obtained;
(1) In the case of isothermal spinning, sufficient accuracy was obtained by selecting a proper collocation number with results in close agreement with those of other investigators.
(2) In nonisothermal conditions, two factors governing the cooling of thread line, cooling air velocity and air temperature strongly influence the resonance wave shape especially the peak level. Since cooling affects draw resonance indirectly through increasing elongational viscosity. Temperature dependence of viscosity also influence its wave shape.
(3) Results of simulation agreed with experiments best when elongational viscosity had the expression;
η=η0exp _??_5300/(T+273)_??_
