Manufacture And Application Of Special Composites Of Automobile Seat Frame

Along with the development of the economics and people’s living standard improving, the number of the automobiles in China has reached the top of the world. It is the automobile that makes our life more convenient. On the other hand, it also brings us many problems, such as environmental pollution and energy consumption. In the wake of the national relevant regulations announcement, automobile lightweight plays a very important role to energy conservation and emission reduction. Because of the properties of fiber reinforced composite, such as low density, high specific strength,short molding cycle, and environmental recycle and so on, it has been researched on comprehensively. Long fiber reinforced thermoplastic composite has partly becoming a substitute for metals and engineering plastics’ components. Long fiber reinforced polypropylene(pp) has the advantages of light mass, high strength, easy molding and low lost. It is the first choice of polymer composites for lightweight of automobile. The materials made into Automobile seat frame experienced from high-strength steel to lightweight composite, but now glass fiber reinforced thermoplastic(GMT) is used more commonly. In this paper, bases on this background, the article will study on the preparation of suitable LFT-PP and apply it to the automobile seat frame according to its performance required.In the case of automobile seat frame, this paper taking glass fiber reinforced polypropylene as the material system studies the preparation of LFT-PP conformed to both bus seat of state standard and the strength of bus fixed components, as well as probing into factors which the injection molding process has influence on the properties of the bus seat. First of all, a technology of LFT granules is proposed with modified double screw extruder, drying installation, fiber cladding mold, cooling installation,Pelletizing plant. Then the properties of the standard molding spine are tested and its microstructure is observed. This article also studies the factors which have an effect on the properties of the product.It turns out that the viscosity of the matrix, the interfacial strength of matrix andresin, the kind and the dosage of compatibizer, the length and the content of the fiber and so on have great influence on the properties of the composite. With the increase of fiber content, the mechanical properties and thermal deformation temperature of composite materials are increased significantly; when the matrix viscosity reduces, it is helpful for impregnation of fiber in matrix and it increases the bond strength of fiber and matrix resin as well as the mechanical properties. Because of the addition of the compatilizer(PP-g-MAH), it significantly improves the combination of the matrix and fiber; at the same time, it enhances the rigidity and strength of LFT-PP, but lowers the impact toughness.Combining with the performance parameters of LFT-PP prepared, the structural design of seat frame is analyzed and optimized by using CAE analysis software ABAQUS. In order to meet the strength required, it increases the wall thickness and adds reinforcement in the areas of stress concentration. Using mold flow analysis software Moldflow simulates the molding process of seat frame. Fiber orientation tensor changing with the different molding conditions such as injection pressure,holding time and mould temperature is researched to reflect the distribution of fiber in the matrix resin by the method of orthogonal design of optimization so that it can Characterize the influence of process conditions on the strength of the product.Meanwhile, this paper utilized CAE to make analysis on the molding technology and obtained the best seat frame when the injection time is 1.54 s, holding pressure is at30 MPa, mould temperature is 90℃ and clamping force is 700 t, which has the important guiding significance and certain application value for the injection molding process and mold design of seat frame.Taking advantage of the in-house production equipment, the product gained from the actual injection mould and tested in automobile factory. The product has been experiment initially by the client, which will make good preparation for its mass manufacture.