三层共挤出吹膜机头流道的流场分析  

Flow Field Analysis of Three-Layer Co-Extrusion Blown Film

作　　者：马秀清[1] 翟文斌 王治鹏 程琨[1] MA Xiuqing;ZHAI Wenbin;WANG Zhipeng;CHENG Kun(College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[1]北京化工大学机电工程学院

出　　处：《塑料》2019年第3期52-56,共5页Plastics

摘　　要：三层共挤吹塑薄膜可将产品的多种特性在挤出过程中进行复合,并能大幅度地降低成本,因而其应用越来越广泛。以 LDPE/HDPE/LDPE 三层共挤出薄膜为例,确定了三层共挤吹膜机头的流道结构,使用 ICEM CFD 对机头流道划分全六面体网格,采用 POLYFLOW 对机头流道内等温流动过程进行求解并分析了压力场、速度场和剪切速率场。机头流道流场的研究结果表明,层分配流道压力降较高,共挤出流道压力降较低;层分配流道存在滞留区,熔体汇入共挤出流道后,相邻层熔体的速度分布向该层速度分布方式不断变化;层分配流道中,沿螺旋槽轴线方向,剪切速率逐渐降低,随着层数的增加,共挤出流道壁面上的剪切速率减小。The three-layer co-extrusion blown film could combine a variety of different characteristics in the extrusion process and significantly decreased cost,therefore the technology was applied more and more broadly. The flow channel geometry of three-layer co-extrusion blown film die was built and then meshed by ICEM CFD with all-hexahedral elements whose isothermal flow field numerical simulation in the co-extrusion flow channel was solved by POLYFLOW to analysis the pressure field,velocity field and shear rate field for LDPE/HDPE/LDPE three-layer co-extrusion blown film. It shows that pressure drop of the layer distribution channel was relatively high and co-extrusion channel low. Retention regions were found in layer distribution channel. Each layer tended to change the velocity distribution type of adjacent layers to the own,when they met the co-extrusion channel. In the layer distribution channel,the shear rate gradually decreases along the axis of the spiral groove. With the increase of the layers' number,the shear rate on the wall of the co-extrusion channel decreased.

关 键 词：多层共挤吹塑薄膜 数值模拟 压力场 速度场 剪切速率场 

分 类 号：TQ320.52[化学工程—合成树脂塑料工业]