Coextruding Blown Film Today Requires Deeper Understanding of Resin Rheology & Die Design

摘要

More film processors are investing in lines with nine or more layers. With more resin possibilities and combinations coming into play, it's important to learn more about material rheology and compatibility, as well as die design. Technology advances in blown film equipment and resins have made coextrusion a "must have" in many applications. But how many layers are enough? In a world where energy prices keep rising, the biggest challenge facing processors is to produce a structure economically with all the properties the application requires. This requires film processors to have a good understanding of the material properties and a good grasp of polymer rheology to achieve the best formulation. Processors also need a better understanding of what happens to these materials inside thi various styles of dies on the market. This article is intended as an overview of topics that bear investigation.