Research On Forming Process And Experiment For Long Glass Fiber Reinforce Polypropylene Composites

Lightweight is one of important approaches to solving problems about energy and environment, and also is significant to sustainable development of the automotive industry. Considering its low density, good comprehensive properties, design-ability, recyclability and cost superiority, long glass fiber reinforced polypro pylene(LGFRP) composites are widely used in automotive industry. With the background of LGFRP composite applied in automobile bodies, the preparation technology and press molding process of LGFRP composite through the method of classification and segmentation are studies in this thesis. Furthermore, the mechanical properties of LGFRP composite are analyzed, and the molding process and process parameters of LGFRP prepreg material are optimized. Detailed contents are listed as follows:(1) The study of material type and preparation technology on LGFRP compositesFor the convenience study of molding process, the LGFRP composite is divided into three types, which are blended fiber blanket, laminated composites and prepreg plate, the structure and performance characteristics of each type material are analyzed respectively, and a kind of thermoplastic resin prepreg is put forward. Furthermore, it introduce the preparation technology and th ree preparation principle s, and designe a lapping machine with multi axial cross lapping according to the structural characteristics and preparation process of blended fiber blanket(2) The study of molding process and trial production of experiment on LGFRP compositesMolding conditions have an important influence on mechanical properties of composite materials. So this thesis subdivide the change of material in forming the moulding process into different parts, and experimente on each part respectively, analyze the mechanism of process parameters influencing on properties of ceramic materials, and chose the appropriate molding process and the process control parameters for different types of materials. Finally, analyze trial-produced LGFRP composite according to study of molding process to establish LGFRP composites molding trial production line.(3) The analysis of experimental mechanics of composite material on LGFRP compositesTo guide the mould materials selection during application, this thesis studie the moulding trial production line of blended fiber blanket, laminated co mposites and three types of prepreg plate material, and analyze the tensile, bending and impact properties of them, and compare their performance.(4) The optimization of molding process and process parameters on LGFRP compositesTo improve the the basic mechanical properties and the stability of performance of LGFRP composite moulded products, this thesis subdivide mould pressing process into the preheating process, molding process, molding and molding design based on LGFRP prepreg material moulding proc ess parameters; and analyze some parameters affecting on the performance of mechanics of materials, and optimize the process parameters of molding.