微注塑成型充模流动中的对流换热行为  

Convective heat transfer behavior of filling flow in micro injection molding

作　　者：于同敏[1] 徐华[1] 田慧卿[1] 徐斌[1] 王乐[1] 

机构地区：[1]大连理工大学精密与特种加工教育部重点实验室,辽宁大连116024

出　　处：《化工学报》2011年第7期1824-1830,共7页CIESC Journal

基　　金：国家自然科学基金项目(50275020);国家重点基础研究发展计划项目(2007CB714502)~~

摘　　要：微注塑成型中,由于尺度效应,使聚合物熔体与微模具型腔壁面间的对流换热行为与常规注塑成型不同,其对流传热系数亦发生了明显变化。通过采用微型注塑机、温度传感器和微模具等组成的对流换热实验装置,对PP、POM和ABS聚合物熔体,以不同的注射速度填充厚度尺寸为0.510、0.420、0.325 mm,表面粗糙度分别为Ra0.062、0.393、0.695μm微型腔时的模具温度分布进行测量,获得了模具的热通量,进而求得熔体与型腔壁面间的对流传热系数。结果表明,微尺度下实验聚合物熔体与型腔壁面间的对流传热系数,均随注射速度和型腔表面粗糙度值的增加以及型腔厚度尺寸的减小而明显增大;但聚合物材料性能不同时,其对流传热系数差别也较大。In micro injection molding,due to scale effect,convective heat transfer behavior between the polymer melt and the wall of micro mold cavity is different from that of conventional injection molding,and convective heat transfer coefficient changes obviously.By using a test device consisting of micro-injection machine,temperature transducer and micro mold,the mold temperature distribution of PP,POM and ABS melt filling the micro-cavity with different injection rates,cavity thickness of 0.510 mm,0.420 mm and 0.325 mm,surface roughness of Ra0.062 μm,0.393 μm and 0.695 μm was experimentally measured.The heat flux in the mold was obtained,and the convective heat transfer coefficient between the melt and the wall of micro-cavity was calculated.The convective heat transfer coefficient in the micro-cavity increased significantly with increasing injection rate,surface roughness of the cavity and the decreasing cavity thickness.For different polymer materials,the convective heat transfer coefficients differ greatly.

关 键 词：微注塑成型 对流换热 型腔厚度 表面粗糙度 

分 类 号：TQ320.66[化学工程—合成树脂塑料工业]