Dry Spinning of Polymer Fibers in Ternary Systems

Abstract

In this work, predictions based on the 2D dry spinning model developed in Part I of this work [2] along with a die swell subroutine supplied by an industrial company, are used to compare with fiber concentration and elongation to break data from an industrial spinline. Die swell ratio predictions agree well with measured values and solidification along the spinline is shown to be due to homogeneous glass transition in the absence of phase separation. Concentration profiles along the spinline are well fit by the model using previously determined prefactors for the diffusion coefficients. A good correlation of elongation at break data is found to occur with a characteristic variable r GTP , the ratio of the rheological force of the viscoelastic Giesekus contribution to the total rheological force (Giesekus + viscous) at the glass transition point. Moreover, the regression obtained from this fit can be further used to make predictions for elongation at break under different operating conditions. Finally, the effects of spinning conditions and model parameters on fiber mechanical properties were investigated.

Simulation of dry‐spinning process of polyimide fibers

“…Recently, the work on dry‐spinning by Gou and McHugh12, 13 presented a modified model with viscoelasticity as well as solidification mechanism. They also developed a two‐dimensional model in ternary system, giving more detailed simulation of CA/acetone/water spinning solution 14, 15. For PAA/DMAC spinning system, water mass fraction is less than 0.3%, so a binary system is adapted for dry‐spinning model in this article.…”

Simulation of polyimide fibers with trilobal cross section produced by dry-spinning technology

“…This model accounts for the viscoelastic nature of the polymer as well as the solidification mechanism of fibers. They also developed a two‐dimensional model in a ternary system that better details the CA/acetone/water spinning solution .…”

Modelling of fibre spinning and film blowing

“…4,5,8 Another goal of the modelling studies has been the development of constitutive equations for application to the dry spinning of amorphous polymers, primarily cellulose acetate (CA). 9,10 In this case, glass transition is the principal solidification mechanism rather than crystallisation. However, similar to the approach taken with the semicrystalline models, solidification behaviour is effectively captured through use of a parallel combination of constitutive components that include both viscous and viscoelastic effects (see Fig.…”

“…Likewise, quantification of the stresses in the filament at the solidification point provides a useful basis for correlating as spun mechanical properties. 10 Because of mass transfer considerations, modelling of dry spinning is inherently a 2D problem. Moreover, consideration of possible moisture (humidity) effects and/or the addition of water to the spinning dope as a rheological modifier, can lead to the need for inclusion of multicomponent mass transfer effects which adds to the complexity of the model.…”

“…Moreover, consideration of possible moisture (humidity) effects and/or the addition of water to the spinning dope as a rheological modifier, can lead to the need for inclusion of multicomponent mass transfer effects which adds to the complexity of the model. 10 1 Constitutive/molecular model for flow enhanced crystallization a network view of Giesekus viscoelastic component; b equivalent micromechanical model 2 phase parallel constitutive model for dry spinning Complete details of all equations and algorithms associated with the results to be reviewed here can be found in the referenced papers at the end of this paper.…”