Lightweight Research On Polypropylene Materials For Automotive Interiors

With the rapid development of the automobile industry,the car plays an important role in the development of the national economy,but there are many problems such as large consumption of fuel and air pollution caused by exhaust emissions.Internal and external accessories are important key parts in the automobile.Under the premise of ensuring strength and safety performance,the lightweight of internal and external accessories is one of the most effective measures to improve the automobile energy saving,braking performance,power and endurance.In this paper,basic magnesium sulfate whisker was used to build skeleton support structure,reduce the material density,provide rigidity and heat resistance of PP composite material by melt blending modification,due to its high strength,high rigidity,high elastic modulus and low density.By optimizing the comprehensive performance and combining with the foaming technology,the PP composite material with the performance requirement of automobile interior and exterior trim was prepared.At the same time,the Moldflow technology was used to analyze the feasibility of lightweight materials and provide solutions and example of polyolefin material for automotive lightweight.The specific research contents and main conclusions of this paper are as follows:(1)The effects of magnesium sulfate whisker content on the density,mechanical properties,fluidity and heat resistance of the composite system were studied by side feeding method,and the distribution and morphology of magnesium sulfate whisker in the system were investigated.Results showed that the whiskers were still in the shape of needle-like fiber with a length of about 15?m and a length-diameter ratio of about 7.5.The whiskers were evenly distributed and had good compatibility with matrix resin.When the whisker content was 10%,the density of the composite was0.967g/cm~3.A small amount of magnesium sulfate whiskers could improve the tensile properties,bending properties and heat resistance of the composite.When excessive amount of whiskers was added,the properties of the composite decreased,and the optimal dosage was 6%.(2)The effects of HMSPP and POE on the fluidity and mechanical properties of the composites were studied.It was found that the addition of HMSPP could improve the tensile and bending properties of the composites,and reduce the fluidity and toughness of the composites.Combined with the requirements of chemical foaming materials,the amount of HMSPP was about 6%.Different grades of POE had different toughening effects on composites.The higher the POE content of the same grade,the better the impact strength and elongation at break,but the worse the tensile strength and bending properties.High flow POE was preferred in this system,and the content was 7-9%.(3)The effect of the amount of silicone on the mechanical properties and the scratch resistance of the composite was studied.The results showed that the amount of silicone was positively proportional to the scratch resistance and inversely proportional to the friction coefficient and whitening degree.The scratch resistance of the composite material surface with silicone added would reach the best effect after be placed for 20h.(4)The lightweight PP material developed by Moldflow simulation and analysis technology was tested by Adobe Central Laboratory in Melbourne,Australia.UDB data of the material was collected and imported into the body parts under the interior panel of the front door of the car for simulation analysis.After analysis by Moldflow software,the prepared lightweight PP composite material was applied to the design of door parts with a wall thickness of 2.2 mm,weight loss of 16%,which could meet the molding and strength requirement.