Design And Performance Study Of LFT Impregnation Die And Fiber Pretreatment Device

Melt impregnation is currently the most widely used impregnation method in industry.In this process,the resin melt is mainly impregnated into the dispersed fiber bundles uniformly.The difficulty lies in how the highly viscous resin melt is impregnated into the fiber bundles with high efficiency and high quality.Domestic and foreign scholars have carried out different designs on impregnating dies and conducted extensive research on immersion theory.Research on impregnation theory is a necessary step in designing impregnation dies and producing products.In this paper,starting from the design of extrusion die for continuous glass fiber reinforced polypropylene composites prepared by melt impregnation method,relying on numerical simulation technology,the pressure distribution of the polymer in the die is analyzed in POLYFLOW.The effects of die temperature,draw speed,impregnation roll spacing,and impregnation roll diameter on pressure were studied.Relying on the calculation model of impregnation degree and impregnation efficiency of fiber bundles,the effects of die temperature,traction speed,impregnation roll spacing,impregnation roll diameter on impregnation degree and impregnation efficiency were studied.Based on the results obtained,the design of the roller-based melt impregnation die was studied.The capability of the mouth die to build up the pressure was studied.The uniformity of simultaneous impregnation of multi-strand fibers was analyzed.Taking into account the effect of fiber preheating,pre-fiber division and other auxiliary components on the fiber impregnation effect,a dispersion heating device and a wire frame were designed.The melt impregnation die designed by ourselves was used for the experiment and the performance of the product was studied.