Co-Extrusion Feedblocks
The coextrusion of two polymer through a simple feed block is shown here. The polymers are fed into the feedblock channel through two different passages separated by a thin plane. The separation plane ends and the two polymers merge forming an interface. As the polymers continue downstream, the interface between them normally distorts. The final shape of the interface at the exit of the channel depends upon the ratio of the viscosities of the two polymers, the ratio of their flow rates as well as the shape and location of the separation plane as demonstrated in the following example.