摘要
本文对HDPE厚壁管的口模定型部分以及后面的冷却定径部分的流动和传热问题进行了分析,建立了数学物理模型。在凝固区两相模型中,提出了求解比热的新的处理方法。运用SIMPLER有限差分程序,结合新编制的子程序,得出了该区域的速度场、压力场及温度场。利用破裂强度值原理,求出了模头后面冷却定径套的长度,该值与文献[5]的实验值吻合较好。本文还通过改变各种工艺条件,得出HDPE熔体在所研究区域的各种场值,用以描述不同条件下的熔体流动情况及冷却情况,为挤出口模定型和冷却定径部分的设计及厚壁管的最佳工艺控制提供了理论基础。
The flow and heat transfer of HDPE thick wall pipe at die parallel lend (DPL) and calibration sleeve (CS) were analyzed in this paper, also a new method for calculating specific heats from DSC diagrams was put forward at melt-solid two phases model. By utilizing general SIMPLER finite differential program and a new user subroutine, the velocity, profile, pressure profile , temperature profile at DPL and CS were obtained. The lengths of CS were obtained basing on velocity profiles,temperature profiles and burst strength values, which are coincident with the experimental values in reference [5]. By changing various processing conditions,different profiles of HDPE melt in the flow field were obtained. Hence the theoretical basis for the design of DPL and CS and optimal processing control of HDPE thick wall pipe was established.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
1992年第4期92-98,共7页
Polymer Materials Science & Engineering
基金
国家自然科学基金
关键词
塑料
厚壁管
挤出
simulation, extrusion, thick wall pipe.
