基于时差和压差的塑料熔体流变性能测试方法研究  

Rheological Properties Test Method of Plastics Melt Based on Time and Pressure Difference

作　　者：裴士轻[1] 曹阳根[1] 李晋昇 殷志鹏[1] 马宏学 

机构地区：[1]上海工程技术大学材料工程学院,上海201620

出　　处：《工程塑料应用》2014年第2期84-88,共5页Engineering Plastics Application

基　　金：上海工程技术大学研究生创新项目(2012yjs15)

摘　　要：利用注塑机、模具调温机、阿基米德螺旋槽模具模拟实际注射过程,借助在模具内置两个压力传感器和数据采集系统,获得了塑料熔体填充过程中的时间压力曲线,从中提取了熔体流经两个传感器的时间差(Δt)及两个传感器压力峰值之差(ΔP)。基于Δt与ΔP计算了高密度聚乙烯熔体的表观剪切速率、表观黏度,在此基础上计算了非牛顿指数(n);基于ΔP与n计算了充填长度,并与充填长度实验值作对比。结果表明,表观剪切速率随着注塑压力的增加基本呈线性增加;表观黏度与表观剪切速率呈指数关系,基于获得的表观黏度与表观剪切速率计算的n与标准值相差不大,表明获得的表观黏度与表观剪切速率值较为可靠;基于压力差与n计算得到的充填长度在其小于1 170 mm时与实际实验值匹配良好,表明获得的n在充填长度小于1 170 mm时较为可靠。The practical injection process was simulated based on the injection machine,mold temperature controller and Archimedes spiral mold,the time-pressure curve in the process of melt filling was obtained by data acquisition system and two pressure sensors installed in the spiral mold,then the time difference （Δt） of melt flow through the two sensors and the peak pressure difference （ΔP） of the two sensors were extracted from the curve. The apparent shear rate and apparent viscosity of high density polyethylene were calculated by means ofΔt andΔP,and the non-newtonian index （n） was calculated based on the calculated apparent shear rate and apparent viscosity. Filling length based onΔP and n were also calculated,and compared with experimental data. The results show that apparent shear rate increases linearly with the increase of injection pressure. The apparent viscosity and shear rate turned out to be exponential relationship. The n values based on the apparent shear rate and apparent viscosity are similar with the standard values,which indicates that the calculated apparent shear rate and apparent viscosity are reliable. Based on differential pressure and flow index,the calculated filling length is matched well with the experimental results when the filling length was less than 1 170 mm,which indicates that the calculated n values are reliable.

关 键 词：注射成型 流变性能 时间差 压力差 测试方法 

分 类 号：TB324[一般工业技术—材料科学与工程]