Abstract: UG software was used to design the geometric structure of eighthole microcapillary film die. And the finite element method was used to simulate the forming section of extrusion die and extrudate parts. Parameter gradual change algorithm was used to investigate the relationship between different tensile stress and the shape or the cross section of extrudate. It showed that with increasing tensile stress, the dimensions of microcapillary film cross section became smaller. The eight air holes were deformed, from the circular to and then diamond, the oval. Because each part had different melt volume content, extrusion surfaces had obvious characteristics of stripe.

Key words: extrusion molding, numerical simulation, microcapillary film