A Novel Mandrel-Free Blown Film Die with Ultrashort Flow Distance and Uniform Discharge: Theoretical Modeling and Simulation

Abstract

In the blown film industry, the nonuniformity in films has been one of the most important problems, and the existing structures of blown films dies have many disadvantages, such as long thermal process and complex structure. This work proposes a novel flow channel structure of blown film die via theoretical modeling and verified by numerical simulations. The results show that the new structure is simple without the mandrel structure that is commonly used in the blown film die, capable of achieving the circumferential uniformity of the film at outlet in an ultrashort flow distance, which can largely avoid the polymer degradation and is well adaptable to different polymers. This work has successfully constructed a special geometry of flow channel without any other complicated elements to achieve uniform discharge, which provides new strategies to deal with the problem of nonuniform film thickness.