Analytical Interpretation of Stress Relaxation Behaviors of Polyester Film -Interpretation by Polynomial Curve Fitting Method-

폴리에스테르 필름의 응력완화거동에 관한 해석학적 고찰 -Polynomial Curve Fitting법에 의한 해석-

To interpretation the overall stress relaxation behaviors of drawn polyester film in solvents(NaOH solution (3$0^{\circ}C$ and 8$0^{\circ}C$) and ionic solutions (KCl and CaCl2)), 5-element mechanical model and its constitutive equations were proposed. And polynomical curve fitting method was chosen as an optimum analytical method and used for the examination of correspondence those equations for overall relaxation process to the experimental data. The polynomial curve fitting program was applied to the interpretation of these relaxation behaviors. As a result, it was shown that the application of the constitutive equations for 5-element mechanical model to the experimental data was reasonable.