3. Two-dimensional thin-film approach

We now turn our attention to the flat die coextrusion process with coextrusion box (figure 5 ). In this case, the challenge is to adjust the position and geometry of the lamellae in the coextrusion box (zone D in figure 5 ), as well as the flow rate of each polymer, to ensure uniformity of the overall thickness of the manufactured sheet or plate, and that of each of its constituent layers, at the die exit. The problems of instability at interfaces mentioned in the previous paragraph are favored by longer...