Interface analysis of three-layer co-extrusion blown film

The three-layer co-extrusion blown film could combine a variety of different characteristics in the extrusion process and significantly decreased cost, therefore this technology is being applied more and more broadly. The flow channel geometry of three-layer co-extrusion blown film die was built and then meshed by ICEM CFD with all-hexahedral elements whose flow field numerical simulation was solved by POLYFLOW to analysis the interface shape and position for LDPE/HDPE/LDPE three-layer co-extrusion blown film. It shows that the interface fluctuates when each layer met in the co-extrusion channel. The differential pressure of two adjacent layers bring about interfacial deformation, interface position changes due to the flow channel rearrangement when each layer met the co-extrusion channel.