The Design Of The Structure And Material And Process Of The Long Fiber Plastic Injection Molded Products

With the shortage of the global energy and serious pollution,the energy conservation and emissions reduction becomes the key problem to be solved.One effective way is lightening the vehicles to reduce energy consumption and exhaust emissions.On this basis,the present subject taken the seat frame of the passenger car as an example,using the lightweight materials and optimizing the preparation technology,meanwhile guarantying the safety performance.Firstly,the long fiber reinforced thermoplastic composites(LFT)with low density was prepared.And then researches on the factors stacking against the mechanical properties of LFT were conducted,such as the interface bonding strength,the fiber length and the orientation degree and so on.The combination of fiber and matrix area and the interface bonding performance were improved by imposing the tension to increase the dispersion property.The mechanical properties of LFT were improved by introducing the different scales of fillings,thus,the fiber orientation degrees were changed,and the homogeneous continuous network structure in the three-dimensional space would be formed.After analyzing the mutual influence between carbon fiber and glass fiber in difference proportions,the strength,stiffness and toughness of LFT using the carbon fiber,glass fiber hybrid enhanced method.In addition,the injection molding process parameters was optimized to adjust the fiber length and orientation to improve the mechanical properties of LFT.Based on the GB13057-2003 regulations,the seat frame has the fracture phenomenon in the position of the welding line,which was formed during the injection molding.The reasons of the decreasing strength of weld line were analyzed according to the fiber content in different position of seat frame.The position of welding line was validated and optimized using the Moldflow software according to welding line formation principles.The welding line was formed in the product mechanical parts by changing the gate location,increasing quantity and the material overflow gate mouth.According to the GB13057-2003 regulations,the seat backplane has the deformation and cracking problems.In accordance to the laws and regulations standard loading method,the accuracy of the seat frame seat frame maximum deformation of stress,strain and stress were validated using ANSYS software.The maximum total deformation,strain and stress were reduced,that improving the mechanical properties of the seat frame by introducing the round shape and edge element method and increasing the thickness of the back.Finally,the problems occurred during the test were analyzed and discussed,this study not only has an in-depth theoretical analysis,but practical significance for the application of the seat frame.