Stability of a two-layer blown film coextrusion

Application of continuation method for tracking steady-state contours in viscoelastic film blowing

“…To derive one-dimensional equations, the following assumptions are involved (Pearson and Petrie, 1970a;Yoon and Park, 2000) -very thin film thickness, axisymmetric bubble, no secondary forces acting on the bubble, and no crystallization in equation of energy.…”

“…There have been many theoretical attempts and experimental observations on this process over last four decades due to its academic and industrial importance (Han and Park, 1975;Kanai and White, 1984;Cain and Denn, 1988;Ghaneh-Fard et al, 1996;Yoon and Park, 2000;Doufas and McHugh, 2001;Fang et al, 2005;Zhang and Lafleur, 2008;Pirkle and Braatz, 2010). Especially, various theoretical issues including stability and sensitivity as well as multiple base flows have been explored for elucidating intricate phenomena occurring in film blowing systems (Hyun et al, 2004;Shin et al, 2007;Pirkle and Braatz, 2010).…”

Production of Market Bag and their Stability and Optimization Parameters

“…The stability of the double components two-layer blown film coextrusion process had been examined using a simple model in which the two layers consist of a Newtonian and an upper-convected Maxwell fluid (UCM), respectively. The final results of the linear stability analysis present that a critical value of the film thickness existed below which the flow becomes unstable (Yoon and Park, 2000).…”

“…Petkim Petryo-chemistry Turkish Company had examined the causes and the solutions of these error reasons. Zatloukal and Vlcek (2004), Muke and vd, (2003) and Yoon and Park (2000) had handled the die design analysis with the results of experimental investigations to test the die design eligibility, bubble stability and had realized the optimization of the process according to that. Moreover, Carneiro vd, (2008) and Zhang and Ajji (2005) had handled the thickness of the film and the factors that affect the thickness in their studies of stability experiment.…”

Investigation of heat transfer in 9-layer film blowing process by using variational principles

“…In spite of a rapid growth of a blown film coextrusion in the last decades, the number of experimental and modeling studies for this process is very limited [5][6][7][8][9][10][11][12] as well as number of works focused on modeling of heat transfer in film blowing process [8,[13][14][15][16][17][18][19][20]. In order to extend the knowledge in this area, the main goal of this work is to investigate effect of the heat transfer coefficient on temperature profile along the bubble for multi-layer film blowing process by using variational principles.…”