气体辅助对聚合物异型材多层共挤成型的影响

Based on numerical simulation and experiment research of isothermal theoretical model, we established the i-shaped multilayer coextrusion 3D non-isothermal viscoelastic model by the finite element method. The flow fields and die swell were studied in the traditional and gas-assisted coextrusion processes. The results show that melt flow rate have great influence on die swell of skin and core melt, but have little influence on the whole die swell of special-shaped product. It can reduce or eliminate the die swell phenomenon and save the energy by gas-assisted coextrusion molding instead of traditional coextrusion molding. The region having the maximum deformation on product is where having the maximum value of shear rate and secondary flow at die exit.