Albert Co
Associate Professor
|
|
| • |
B.S. University of the
Philippines, 1972 |
| • |
Ph.D. Ph.D. University of
Wisconsin - Madison, 1979 |
|
|
 |
Research Interests
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.
|
