Research On The Molding Process And Properties Of Hemp Fiber Composites Used In Automobile’s Inner Parts

In recent years, with the strengthening of the human environmental awareness and the demand of the automobile lightweight, the fiber reinforced composite board has been recognized by automobile industry, such as ramie, jute and flax. The hemp fiber, as a kind of bast fiber, has the advantage of low density, high strength and rigidity, small elongation, abrasion resistance, moisture absorption and good perspectivity and so on. Especially,it is also accessible to human beings, friendly and sustainable to environment,which makes it have huge advantage to apply to car inner decoration instead of GMT materials. So it is necessary to study the forming process of the hemp composite automobile interior trim parts.This paper mainly studied the application of hemp composite material in automobile interiors. According to the manufacturing process of GMT, the method was put forward for the molding of the hemp fiber composite board and automobile interior trim parts. The blend fiber needling felt ware mixed by the hemp fiber which had been mechanical degummed and the modified polypropylene. Then the felt was pressed into the hemp composite material automobile inner parts. In the components of hemp fiber, in addition to the stable cellulose, there are some unstable brittle material, like pectin, hemicellulose and so on, which would not only affect the properties of hemp fiber composites, but also it was the main reason of the volatile aldehydes that was produced when the hemp fiber was heated. So it was necessary to degum the hemp fiber mechanically. The hemp fiber was a strong polar hydrophilic macromolecule, while polypropylene was nonhydrophilic polymer, the third component such as silane coupling agent was used to improve the compatibility between the hemp fiber and polypropylene fiber. In this paper, the process of hemp fiber composites had been analyzed. The parameters in the molding process affectingthe forming process, such as preheating temperature, pressing time and molding pressure and so on were studied to determine the reasonable molding date. And the molding process of the hemp composite automobile inner decoration was researched and analyzed in detail. The same time, the problem had been solved that the shell fabric and the hemp fiber was put together.The ANSYS finite element method has been used to analyze the tensile properties of the hemp composite material board, which simulates the damage process of sample. More detailed information of the tensile test was shown by the ANSYS simulates.