Study On The Moulding Process And Properties Of Jute Fiber Reinforced Polypropylene Composite For Automobile

The lightweight design of vehicle body has a positive significance for the sustainable development in the automotive industry,with the increasingly severe energy crisis and environment pollution problems,the applications of composite material as an important direction to achieve lightweight has been paid more attention.Compared with the traditional thermosetting matrix composite,jute fiber reinforced polypropylene(JF/PP)composite is cheaper and can be recycled,owning to its good mechanical properties and acoustic property,they have been widely applied in automobile industry especially in interior parts.Compression moulding process has been abroadly used for manufacturing fiber reinforced composite due to its low cost,high production efficiency and good dimensional precision.Focusing on improving the properties and the quality of the JF/PP composite,a comprehensive study was made on the moulding process and properties of JF/PP composite in this paper,main contents and innovations which include:(1)The JF/PP mixed fiber mat was prepared by air-laid process to improve the impregnation effect in the composite.The probability of the fiber distribution in each direction was equal and the JF/PP mixed mat presented a three-dimensional structure which can enhance the overall properties of JF/PP composite.(2)Three process parameters including moulding temperature,moulding pressure and moulding time were investigated by using quadratic rotation-orthogonal combination design and response surf-ace method in order to enhance the mechanical property of JF/PP composite.Response surface models of tensile strength and flexural strength were established,and the contribution of factors was ordered by ANOVA,single factor effect and interaction effect were both analyzed,then the processing parameters can be optimized,so the final optimized processing parameter combination was:moulding temperature-188.5℃,moulding pressure-5.2MPa,moulding time-12 mins.(3)The mechanical property and acoustic property of JF/PP composite which contained different stacking types were investigated under the optimized process parameters condition,the tests showed that stacking types had a certain influence on the mechanical properties and acoustic property of JF/PP composite,and the acoustic property was improved when more stacking layers were used,the lowest resonant frequency of JF/PP composite was around 300 Hz and the critical frequency of coincidence effect was around 1000 Hz.The results indicate that the optimized combination of process parameters obtained by considering the interaction among those factors can further improve the mechanical properties of JF/PP composite.It provides a reliable experimental basis and reference for the engineering application through the tests and investigations on compression moulding and acoustic property in this thesis,and plays an important role in applying the JF/PP composite into the automobile interior parts in the next step.