汽车内饰用秸秆纤维/聚丙烯复合材料流变本构方程的建立

Establishment of rheological constitutive equation for straw fiber/polypropylene composites using in automotive interior

以秸秆纤维/聚丙烯(PP)母粒和PP为主要原料,利用双螺杆挤出机共混挤出造粒制备了不同纤维含量的汽车内饰用秸秆纤维/PP复合材料。通过对复合材料的压力-比容-温度(PVT)特性和黏度特性进行测试分析,建立了不同秸秆纤维含量的秸秆纤维/PP复合材料的PVT曲线和黏度曲线,探讨了纤维含量对材料PVT特性和黏度特性的影响规律。分别使用修正的双域Tait状态方程和Cross-WLF黏度方程对PVT曲线和黏度曲线进行参数拟合;基于拟合结果的分析,最终建立了考虑秸秆纤维含量影响的修正PVT模型与黏度方程。基于Moldflow分析软件建立了材料属性文件,对某汽车门饰板进行了模流分析。结果表明,建立的复合材料流变方程可有效用于注塑成型数值模拟分析。

Using straw fiber/polypropylene(PP) masterbatch and PP as the main raw materials, straw fiber/PP composites with different fiber contents were prepared by twin-screw extruder. The pressure specific volume temperature(PVT) and viscosity curves of the composites with different straw fiber contents were established by testing and analyzing the PVT and viscosity characteristics of the composites. The influences of fiber contents on the PVT and viscosity properties of the composites were discussed. The modified two-domain Tait equation of state and Cross-WLF viscosity equation were used to fit the parameters of PVT curve and viscosity curve respectively. Based on the analysis of fitting results, the modified PVT model and viscosity equation were established considering the influence of straw fiber content. Applied in Moldflow analysis software, the material properties data file was established, and the mold flow analyses of an automobile door trim panel were carried out. The results show that the established composite rheological equation is effective in numerical simulation analysis of injection molding.