ENTEG guest seminar given by Dr N.D. Polychronopoulos entitled Understanding the production of plastic films, sheets and tapes through mathematical modeling
|When:||We 08-06-2016 15:00 - 16:00|
Calendering, film casting and pultrusion are frequently used for the production of polymer films, sheets and composite tapes. In calendering, the molten polymer is conveyed between two heated counter-rotating cylinders. Fully 3D numerical simulations, assuming a shear-thinning polymer melt, reveal that the forming sheet or film laterally spreads between the cylinders via a sideways spiraling motion, fully in agreement with experimental evidence. The process of film casting entails the stretching of a film, emerging from a rectangular die, by means of a rotating chilled cylinder located far in front. Upon emergence from the die the film locally swells. Using the Phan Thien-Tanner viscoelastic model, the extrudate swell phenomenon under the influence of stretching was studied. In pultrusion, the fluid penetration depth into a flexible and permeable tape that moves over a cylinder was determined. This configuration is also encountered in rolling and printing. The results of the computer simulations can be used for process optimization purposes.