蒸汽加热变模温注射成型数值模拟与结果分析

采用Moldflow软件对变模温注射成型过程进行数值模拟。利用蒸汽加热和冷却水冷却的变模温注塑工艺，研究不同蒸汽加热时间下注塑位置处压力以及制件冷凝层的变化规律，同时分析了制件表面和模具型腔表面的热响应规律。结果表明，相比于传统注射成型工艺过程，变模温注射成型通过提高注塑充填过程中模具温度，使得制件冷凝层出现在充填阶段之后；随着模具加热时间从10、15、25 s增加到40 s，注塑位置处最大注射压力从87.0608、84.6064、79.6863 MPa减小到74.4342 MPa,大大提高了熔体注塑充填过程中的充填能力；通过不同的蒸汽加热时间，制件表面和模具型腔表面可以获得不同的温度值，同时通过模拟获得了传热系数对制件表面温度的影响。

Numerical Simulation and Analysis of Variotherm Injection Molding Technique by Using Steam Heating

A variotherm injection molding technique with steam heating and coolant cooling was simulated by Moldflow. Pressures at injection location and frozen layer of part at different heating time were studied, and the thermal response at surface and cavity of the mold waqs analysed using constructed models. Compared with traditional injection molding, in the variotherm injection molding the mold temperature was increased to a designed value, the melt could easily fill into the cavity under a low injection pressure, and the frozen layer was appeared after the filling stage. As the mold heating time increased from 10 to 15, 25, 40 s, the maximum pressure at injection position was reduced from 87.1 to 84.61, 79.7, 74.4 MPa, respectively. The surface temperature of the part and the mold could be changed through different heating time, and the part surface temperature was simultaneously affected by the heat transfer coefficient.