Many polymers are extruded through blown film dies to produce monolayer and multilayer films. The most popular style of die in use today to produce blown films is the spiral mandrel die. This type of die can be used effectively for many polymers but cannot easily be used with thermally sensitive materials due to long flow paths and large surface areas that can lead to polymer degradation. This paper will discuss a new, unique blown film die technology in which a thermally sensitive polymer is encapsulated with a less sensitive material and processed into a blown film. Experimental data will be shown on the viscosity of encapsulated melts and the unique flow patterns in the die.
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