摘要
针对微尺度聚合物熔体粘性耗散效应与宏观尺度的差别,应用高聚物流变学的基本理论分析微注塑成型充模流动时粘性耗散对熔体流变行为的影响。并以双料筒毛细管流变仪为测试平台,设计粘性耗散测量装置。选用直径500μm毛细管口模,以高密度聚乙烯(Higdensity polyethylene,HDPE)和丙烯腈-丁=烯-苯乙烯共聚物(Acrylonitrile butadiene styrene,ABS)材料进行不同温度与不同剪切速率下的粘性耗散试验研究。结果表明粘性耗散引起的熔体温升随着剪切速率的增加而升高;而当熔体温度增加时,同一剪切速率下粘性耗散效应引起的温升却在下降。粘性耗散的理论计算结果表明,随着剪切速率的增加,微通道壁面处熔体的粘度降低明显,因而建立微注塑成型流动理论模型时,不可忽略粘性耗散效应的影响。
The polymer melts viscous dissipation effects of micro scale dimensions are different from that of macro-scale dimensions.The affect of viscous dissipation in micro injection molding on the rheological behavior of melts is analyzed by using the basic rheological theory of polymer melts.The viscous dissipation measurement device is designed on the basis of two-cylinder capillary rheometer.Experimental studies of viscous dissipation at various shear rate are investigated with several polymers,including achylonitrile butadiene styrene and high density polyethylene,at different temperature when melts flow through 500 μm size diameter micro channel.The results indicate that the temperature rise caused by viscous dissipation increases with increasing shear rate and the temperature rise for some shear rate decreases with increasing melts temperature.The theoretical calculation of viscous dissipation reveals that the viscosity of melts near wall reduces obviously with increasing shear rate.Therefore the influence of viscous dissipation should not be neglected when the theoretical model of mold filling flow in micro injection molding is established.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2010年第14期47-52,共6页
Journal of Mechanical Engineering
基金
'十一五'国家科技支撑计划重点(2006BAF04B13)
国家自然科学基金(50805015)
国家重点基础研究发展计划(973计划
2007CB714502)资助项目20090628
关键词
微注塑成型
聚合物熔体
粘性耗散
流变测量
微尺度
Micro injection molding Polymer melts Viscous dissipation Rheological measurement Micro scale
