Diffusion-convection model for interphase formation and process simulation of bicomponent fiber

The interphase of bicomponent fiber formed during co-extrusion is a key factor to influence the interfacial adhesion of the two components, which was not disclosed well by experiment or simulation. To simulate the interphase distribution which cannot be obtained by traditional interface boundary conditions, a mathematical model introducing the combined effects of diffusion and convection process was developed and the interphase thickness dependency nature of the extent of adhesion of bicomponent fiber was revealed visually. It was found that convection was the dominant effect on interphase formation at the low diffusion coefficient and the flow rate difference between the two components would facilitate the interphase development. Finally, the critical total flow rate of convection-dominated formation and diffusion-dominated formation of the interphase was found to be 2.0 x 10-4 kg/s. The interphase formation simulation was verified by experiment, which can provide an effective means for the study of interface control of bicomponent fiber.