依据傅里叶定律和能量守恒方程的基本原理,对聚合物注射成型冷却过程进行了合理假设和必要简化,采用数学模拟结合实验验证的方法,对高密度聚乙烯(PE-HD)和聚丙烯(PP)共混物注射成型冷却过程进行了实验和数值模拟研究。采用数据采集器对不同比例共混物注射冷却过程中的温度变化进行了数据采集。结果表明,在冷却第一阶段纯PE-EID的冷却速率最快,在固相冷却段共混物的冷却速率较纯净物慢。将采集所得温度的实验值与根据改进焓法用Matlab软件对共混物冷却过程中温度分布数值模拟计算所得的值进行了比较分析,结果表明,共混物在冷却第一和第二阶段的温度分布实验值与模拟值几乎完全吻合,在固相冷却段共混物的冷却受热导率和聚合物的形态结构的共同影响,此阶段实验值略高于模拟值。
Via the numerical simulation coupled with experimental measurements, high-density polyethylene (PE-HD) and polypropylene (PP) were melt-blended in the following percentages of PE-HD by weight :0, 25, 50, 75,100 and injected in the injection molding. Under some assumptions, the temperature profiles are numerically solved through the mathematical software package Matlab. The relationship between the percentages of PE-HD by weight and the values of the thermodynamic parameters is also concluded in the article. The model was tested by measuring the temperature profiles in a slab mold instrumented with a thermocouple. Measurements of temperature profiles show good agreement with the numerical prediction during the liquid cooling stage as well as the phase change process, whereas the theoretical values are a bit larger than the experimental ones.