The effect of viscoelasticity on multilayer polymer extrusion is discussed. In these coextrusion processes predeterminedpatterns are created with a remarkable breadth of complexity even in geometrically simple dies viaelastic rearrangements caused by the second-normal stress differences. A computational method is offered,based on the mapping method, which quantitatively describes the flow-induced patterns. Besides that theresults are esthetically beautiful, they are also relevant for practice, since process and die design optimizationis now possible. Not only to minimize interface distortion, but potentially also to deliberately create new processesand products based on this flow-induced patterning of polymers.
|Publication status||Published - 2006|