仿真研究聚丙烯流变性能对气辅注塑的影响

COMPUTER SIMULATIONS ON EFFECT OF RHEOLOGICAL PROPERTIES OF POLYPROPYLENE ON GAS-ASSISTED INJECTION MOLDING

应用计算机仿真手段研究了不同聚丙烯在充模速度相同条件下的压力及销模力变化规律。结果表明,气辅注塑与传统注塑相比,所需压力、锁模力均有显著降低,且聚合物熔体流动速率越小,气体注射后产生的压力降越大。

The effect of rheological properties of polymer melts on gas-assisted injection molding has been studied by means of computer simulation. The entrance pressures and clamp forces of five grades of polypropylene resins are discussed for conventional and gas-assisted injection molding processes at the same mold filling rate. The result showed that a gas-assisted process required much lower entrance pressure and clamp force than a conventional injection process. The pressure difference after gas injection decreased with the material melt flow index, which indicated that gas-assisted injection molding, compared to conventional molding, could improve the processiability much better for a low MFR material than a high MFR material. And on the other hand, a material of high MFR would be favorable in gas-assisted injection molding.