摘要
在反应注射成型实际生产过程中，如何选择工艺参数是一个一直使操作者为难的问题。本文利用反应注射成型过程中驻留时间的概念，通过对喷泉流模型进行适当的简化分析，得出在ＲＩＭ充模过程中驻留时间与模腔无量纲纵向ｘ坐标和模腔厚度ｚ坐标之间的关系，并得出最大驻留时间线１＝２ｘ３（１－ｚ２），作出充模过程驻留时间分布曲线。忽略ＲＩＭ充模过程的热传导项，无量纲温度Ｔ与反应进度Φ相同，是流体在模腔内驻留时间线的等值线。将数值计算的反应进度值、温度值与模型计算作比较，基本符合，偏差的出现是由于模型中对前流区的简化处理，恒定粘度假设以及忽略热传导作用。为避免在充模过程中出现过早凝胶现象，在反应进度达到凝胶点时驻留时间不应大于１。
How to choose the processing parameters has been a difficult problem to operators in the production of reaction injection moulding (RIM).The relation of the resident time of the filling process in RIM with the non dimensional ordinate and the mould cavity thickness coordinate z was obtained by means of simplifying a fountain model,based on the conception of the resident time in RIM.The maximum resident time line 1=2 3(1-z 2) was calculated and the distribution curves of the resident time of the filling process were made.When the heat transfer term in the filling process of RIM was ignored,the non dimensional temperature ,as well as the reaction progress φ ,was an isopleth to the resident time line of the material in the cavity.Compared with the results of model calculation,the reaction progress and temperatrure from the numerical method basically conformed with those from model calculation,deviations were the results of the simplifying treatment of the front flow part,the assumption of constant viscosity and the ignorance of the heat transfer.In order to avoid the early gelation in filling process,the resident time should not be greater than 1 when the reaction processed to the stage of gel point.This conclusion would be helpful to the choice of the processing parameters of RIM processing.
出处
《塑料工业》
CAS
CSCD
北大核心
1996年第4期76-79,共4页
China Plastics Industry
关键词
充模过程
注塑成型
模具
塑料
Reaction Injection Moulding Filling Process Resident Time
