Polymer processing • non-Newtonian fluid dynamics • rheology • transport phenomena • applied numerical methods
- Viscoelastic Processing Flows
Either shear flow or extensional flow dominates various types of polymer processing flows. It is important that this be identified so that appropriate rheological measurements can be made to characterize the polymer melts. We are conducting numerical simulations and experimental studies of the viscoelastic flow in the drawing zone of single-layer and multi-layer film casting of different polymer melts. Here extensional flow plays a dominant role. Velocity profiles and film tensions are measured under various processing conditions. In addition, the effects of polymer rheological properties and operating conditions on flow instability (draw resonance) and edge phenomena in film casting are being investigated. Information obtained can be used to optimize the production of polymer films.
- Non-Contacting Tension Measurement in Films
In the processing of films, the ability to measure film tension is essential in achieving better control of the process. Due to the molten state of polymer film or its high velocity, the measuring device must not be in contact with the film. We have developed a non-contacting air-nozzle system that can measure the instantaneous tension in a film. We are applying this system to measure film tension in polymer film processes such as film casting and film blowing.
- Book Chapters
Co, Albert. Draw resonance in film casting. In: Hatzikiriakos, S. and Migler, K, Editors. Polymer processing instabilities. Mercel Dekker; 2004; pp. 287-319.
Bousfield, Douglas W. and Co, Albert. Paper coating rheology. In: Siginer, D. A.; DeKee, D., and Chhabra, R. P., Editors. Advances in the flow and rheology of non-Newtonian fluids. Elsevier; 1999; pp. 827-842.
- Selected Papers
Canning, Kathleen; Bian, Baigui and Co, Albert. Film casting of a low density polyethylene melt. Journal of Reinforced Plastics and Composite. 2001; 20(5):366-376.
Canning, Kathleen and Co, Albert. Edge effects in film casting of molten polymers. Journal of Plastic Film and Sheeting. 2000 July; 16(3):188-203.
Bian, Baigui and Co, Albert. Non-contacting measurement of molten films. Polymer Engineering and Science. 1999 May; 39(5):841-848.
Bian, Baigui and Co, Albert. Tension in multilayer film casting of polymer melts. Journal of Reinforced Plastics and Composite. 1999; 18(4):319-330.
Pis-Lopez, Maria E. and Co, Albert. Multilayer film casting of modified Giesekus fluids: Part 2. Linear stability analysis. Journal of Non-Newtonian Fluid Mechanics. 1996; 66:95-114.
Pis-Lopez, Maria E. and Co, Albert. Multilayer film casting of modified Giesekus fluids: Part 1. Steady-state analysis. Journal of Non-Newtonian Fluid Mechanics. 1996; 66:71-93.
Iyengar, Vardu R. and Co, Albert. Film casting of a modified Giesekus fluid: Stability analysis. Chemical Engineering Science. 1996; 51(9):1417-1430.
Mantar E.; Co, Albert and Genco, Joseph M. Drainage characteristics of pulp slurries under dynamic conditions. Journal of Pulp and Paper Science. 1995 Feb; 21(2):J44-J50.
Iyengar, Vardu R. and Co, Albert. Film casting of a modified Giesekus fluid: A steady-state analysis. Journal of Non-Newtonian Fluid Mechanics. 1993; 48:1-20.
Antukar, Nitin R. and Co, Albert. Draw resonance in film casting of viscoelastic fluids: A linear stability analysis. Journal of Non-Newtonian Fluid Mechanics. 1988; 28:287-307.