Research On Preparation And Properties Of Continuous Glass Fiber Reinforced Polypropylene Prepreg Tape

Continuous fiber reinforced thermoplastic prepreg tape(CFRTP)has been widely used in the industrial field due to it's excellent properties,like mechanical properties and good design ability.And it has been transformed from sub-structural parts to main bearing parts.Melt impregnation process is one of the main methods for the preparation of CFRTP.How to accurately characterize the impregnation of continuous fiber bundles by thermoplastic resin is the key to evaluate the impregnation effect of prepreg and improve the melt impregnation process.Compared with thermosetting resins,the high viscosity and difficulty in impregnation of thermoplastic resins are the main factors that limit the processing method and production efficiency of CFRTP.The mechanical properties are the important parameters that determine the application of composite materials.The exploring for the intrinsic relationship between the mechanical properties of composite materials and the raw materials will provides guidance on the prediction of the performance of composite materials and the improvement of processing methods.This article focuses on the above three points,including impregnation mechanism,process parameters'optimization,reduction of melt viscosity,and tensile properties' analysis four aspects.Based on Darcy's law,the melt impregnation behavior of Carreau fluid on glass fiber bundles was investigated in detail.The corresponding impregnation theoretical model was established and the accuracy of the model was verified by experiments.The three constitutive equations of Newton,power law,and Carreau were used to compare the prediction ability of the final impregnation models.Based on the impregnation model,the effects of mold structure parameters and processing parameters on the impregnation degree were analyzed.The influence degree of each factor on the degree of impregnation was obtained and the best parameter combination was optimized by using the DOE experiments.In order to reduce the viscosity of matrix,the higher viscosity polypropylene was mixed with the lower.Matrix rheological tests were performed to determine the viscosity reduction effect of different proportions.Melt impregnation experiments were performed to analyze the processing performance of CFRTP and the mechanical properties of the final composite material.The results show that the method can effectively improve the processing speed and impregnation degree,increase the production efficiency on the basis of basically maintaining the mechanical properties of the material.Experiments were conducted in a laboratory production line to compare the relationship of the modulus and tensile strength of long glass-reinforced polypropylene and continuous fiber reinforced polypropylene composites with the material parameters and fiber content.The theoretical models were used to predict the tensile properties of the above two composites and the corresponding empirical coefficients were obtained,which provided a reference for the analysis of tensile properties of composites.