基于联合仿真的短纤维增强聚合物共混挤出-注塑成形全流程模拟

Full Process Simulation of Short Fiber Reinforced Polymer Blend Extrusion-Injection Molding Based on Co-Simulation

短纤维增强聚合物广泛应用于汽车、电子、机械等领域,共混挤出和注塑成形是其最常见的制备和成形工艺。现有共混挤出与注塑成形的模拟仿真存在材料和工艺信息孤立、产品优化协同困难的问题,难以满足聚合物产品高端化与定制化的发展需求。文中提出了一种短纤维增强聚合物共混挤出-注塑成形过程的联合仿真方法,建立共混挤出过程全区域流场计算模型,基于流场模拟实现纤维断裂和纤维长度分布模拟,在此基础上,建立考虑纤维含量的流变与压力-比容-温度(PVT)模型计算材料等效热力学参数,通过模流-结构性能求解注塑拉伸试样的纤维取向与弹性模量分布,实现共混挤出-注塑成形全流程模拟。纤维质量分数为20%,30%和40%的玻纤增强尼龙6注塑拉伸试样弹性模量实验与模拟结果相对误差分别为9.94%,8.32%和3.72%,验证了联合仿真的准确性。

Short fiber reinforced polymers are widely used in automotive,electronic,mechanical,and other fields.Blending extrusion and injection molding are the most common preparation and forming processes,respectively.Existing simulations of blend extrusion and injection molding have the problems of material and process information isolation,and product optimization coordination difficulty,which cannot meet the development needs of high-end and customized polymer products.This paper proposed a co-simulation method for short fiber reinforced polymer blend extrusion-injection molding process.A full area flow field calculation model for blend extrusion process was first established.Based on the flow field simulation,the fiber fracture and fiber length distribution were simulated.On this basis,the rheological and PVT model considering fiber content were established to calculate the equivalent thermodynamic parameters of materials,the fiber orientation and elastic modulus distribution of the injection molded tensile samples were calculated through the mold flow-structure properties.The relative errors between the experimental and simulation results of elastic modulus for the injection molded tensile GF/PA6 samples with the fiber content of 20%,30%and 40%are 9.94%,8.32%,and 3.72%,respectively,which verify the accuracy of the co-simulation method.