High-speed fiber spinning process with spinline flow-induced crystallization and neck-like deformation

An Overview of Molten Polymer Drawing Instabilities

“…When the stretching distance L is sufficiently large, more complex phenomena occur as stress induced crystallization involving changes in the temperature field. This may result in a strong necking phenomenon in the crystallization zone which prevents from the drawing instability development (Shin et al, 2006;Kohler and McHugh, 2008). When stretching polymers of increasing elasticity in quasi-isothermal conditions, the critical Draw ratio remains first more or less constant and then the periodic instability disappears and frequent filament breakages are then observed (Chang and Denn, 1979).…”

“…McHugh (2007, 2008) used a linear stability analysis and both Giesekus and Pom-Pom viscoelastic models to describe the response of the spinning line to a small variation of a spinning parameter in stable processing conditions. Interestingly, Shin et al (2006) followed the real part of the dominant eigenvalue as a function of the take-up speed and pointed out the stabilizing effect of the necking phenomenon.…”

“…More realistic viscoelastic models have been introduced by Lee et al (2001) as Jung et al (1999) coupled the UCM model and heat transfer. Lee et al (2005), Shin et al (2006) as well as McHugh (2007, 2008) introduced stress induced crystallization and the corresponding crystallization energy in the temperature balance equation. McHugh (2007, 2008) used a linear stability analysis and both Giesekus and Pom-Pom viscoelastic models to describe the response of the spinning line to a small variation of a spinning parameter in stable processing conditions.…”

Sensitivity of spinning process with flow-induced crystallization kinetics using frequency response method

“…

The sensitivity of the low-and high-speed spinning processes incorporated with flow-induced crystallization has been investigated using frequency response method, based on process conditions employed in Lee et al [1] and Shin et al [2,3]. Crystallinity occurring in the spinline makes the spinning system less sensitive to any disturbances when it has not reached its maximum onto the spinline in comparison with the spinning case without crystallization.

…”

Direct Calculation of Limit Cycles of Draw Resonance and Their Stability in Spinning Process

“…As one of industrially and academically important issues, this instability has been theoretically and experimentally exploited by many researchers during four decades. [1][2][3][4][5][6][7][8][9][10][11] Onsets of draw resonance can be typically found by the linear stability method introducing infinitesimal perturbations at state variables from the steady states 3,4,[12][13][14] or frequency response method adopting the transfer function concept in the linearized system. 15,16) And also, periodic solutions or limit cycles of draw resonance which are nonlinear characteristic nature, have been computed by dynamic transient simulation with initial conditions, e.g., a step change of take-up velocity from steady states.…”