Study On Injection Molding Of Fiber Reinforced Polypropylene Composites For Automobile Interior Decoration Based On Moldflow

In recent years, with the rapid increase in automobile production and ownership,resource and environmental issues have become increasingly prominent, automotive lightweight and environmental protection become the direction of development and research focus.More and more car manufacturers use the composite materials to replace the traditional automotive materials making the automobile lightweight to achieve the goals of saving energy and reducing emission of pollution reduction.Especially the hemp fiber reinforced composite materials attract widespread attention by the virtues of its low density, high strength, good mechanical properties and can be renewable, biodegradable, recyclable, low-priced and so on. The hemp fiber reinforced composite materials made by ramie, jute and flax have been recognized by the automotive industry. Therefore the automotive productions made by the hemp fiber reinforced composites materials has an important significance.Firstly, this thesis introduces the types of molding progress and research progress of the hemp fiber reinforced composite materials, then introduces the development of injection molding simulation technology in domestic and foreign. Describes the the basic process of injection molding and the theory of the mode involved. Introduces the simulation software- Moldflow including its various module functions.Secondly, this thesis chooses polypropylene as the based materials, natural hemp fiber as the reinforced materials, an automobile interior parts as the research object. It uses injection molding simulation software-Moldflow to prepare hemp fiber reinforced composite materials. Then through the three-dimensional mapping software to construct the model diagram of the automotive interior part, import in the Moldflow software to mesh, diagnosis and repair. Select a molding material and set the parameter of fiber. We setup the initial gate position according to the design principles of gating system.Using mathematical models associate with simulation software designs the runner system checked by the corresponding shear rate.Using integration analysis method including gate position and runner systems determines gate location. Through theoretical calculations to create a cooling system according with the design principles. Optimizes the cooling system for the particularity of the part of the cooling system.Again based on the total warpage amounts and sink marks of parts as indicators,the injection molding process parameters(including melt temperature, mold temperature, filling time, holding pressure) as factors, each factor takes three levels to design Orthogonal experiment and analysis in the Moldflow one by one. Make the optimum injection molding process parameters according to the degree of influence of various factors on the test indicators and the quality of various levels. Under the optimal injection molding process parameters, simulate the injection molding parts and get the most optimal amount warpage and sink marks of parts to obtain the best quality parts. Analysis the fiber orientation under the best process parameters to predict the mechanical properties of the parts.