气泡在扭转元件中的流动分散行为
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摘要
螺杆作为微发泡注射成型技术的核心部件,对超临界流体在聚合物中的溶解和分散具有关键的作用。对气泡在扭转元件中的流动分散行为进行了动态可视化试验与数值分析。结果表明,扭转元件具有强化径向传质的作用,使熔体发生径向扭转翻滚,进而使溶解在熔体中的气泡在扭转元件分割槽内发生拉伸塑性变形,破碎成更小的气泡并均匀分散在熔体中。同时,扭转元件中熔体的升温速率比螺纹元件快,熔体内温度分布更加均匀,有利于气泡分散相的稳定。相对于螺纹元件,扭转元件的分离尺度更小,混合性能更佳,并基于此,设计了一种高效混炼的Mucell微发泡专用螺杆。
As the core component of the microcellular injection molding technology,the screw had a key influence on the dissolution and dispersion of supercritical fluid in the polymer. Dynamic visualization experiment and numerical analysis were carried out on the flow and dispersion behavior of bubbles in torsion elements. The results showed that the torsion element had the effect of strengthening the radial mass transfer,making the melt twisting and rolling in radial direction,and then making the bubbles dissolved in the melt to generate tensile plastic deformation in the channel of torsion element and breaking into smaller bubbles and dispersing in the melt evenly. At the same time,the heating rate of the melt in the torsion element was faster than that of the screw element,so that the temperature distribution in the melt was more uniform,which was conducive to the stability of the dispersed phase of the bubble. Compared with the screw elements,the separation scale of the torsion elements was smaller and the mixing performance was better. Based on this,a kind of Mucell microcellular special screw with high efficiency mixing was designed.
As the core component of the microcellular injection molding technology,the screw had a key influence on the dissolution and dispersion of supercritical fluid in the polymer. Dynamic visualization experiment and numerical analysis were carried out on the flow and dispersion behavior of bubbles in torsion elements. The results showed that the torsion element had the effect of strengthening the radial mass transfer,making the melt twisting and rolling in radial direction,and then making the bubbles dissolved in the melt to generate tensile plastic deformation in the channel of torsion element and breaking into smaller bubbles and dispersing in the melt evenly. At the same time,the heating rate of the melt in the torsion element was faster than that of the screw element,so that the temperature distribution in the melt was more uniform,which was conducive to the stability of the dispersed phase of the bubble. Compared with the screw elements,the separation scale of the torsion elements was smaller and the mixing performance was better. Based on this,a kind of Mucell microcellular special screw with high efficiency mixing was designed.
引文
[1] ANON. Ticona establishes laboratory Mucell microcellular moulding technology[J]. Plastics, Additives and Compounding,2001,3(4):5.
[2]唐锦荣. MuCell微发泡注塑成型技术应用[J].国外塑料,2011,29(4):60-61.
[3]赵惠英.微发泡注射成型[J].国外塑料,2004,22(5):49-50.
[4]何亚东.聚合物微发泡材料制备技术应用研究进展[J].塑料,2004,33(5):9-15.
[5] HEIM H. Specialized injection molding techniques[M]. New York:William Andrew,2016:53-106.
[6]翟明,陈建平.微孔泡沫塑料的制备工艺与设备[J].橡塑技术与装备,2016,42(10):44-45.
[7] GAUB H. Profoam—cost-efficient process for manufacturing foamed lightweight parts[J]. Reinforced Plastics,2017,61(2):109-112.
[8]杨伟,武力军,李瑞文,等.物理微发泡微开模注塑成型技术[J].模具技术,2017,(4):52-58.
[9]余坚,何嘉松.超临界CO2技术制备微孔聚合物中的基本问题[J].中国科学:化学,2010,40(1):1-15.
[10] XU J.微孔塑料注射成型技术[M].张玉霞,王向东,译.北京:机械工业出版社,2013:229-230.
[11]北京化工大学.聚合物熔体微积分强化传热与混炼塑化挤出机:中国,CN103753793A[P]. 2014-04-30.
[12]鉴冉冉,谢鹏程,杨卫民.基于场协同原理的聚合物塑化过程数值分析[J].工程热物理学报,2017,38(2):281-288.
[13] JIAN R,YANG W,CHENG L,et al. Numerical analysis of enhanced heat transfer by incorporating torsion elements in the homogenizing section of polymer plasticization with the field synergy principle[J].International Journal of Heat and Mass Transfer,2017,115,Part A:946-953.
[14]鉴冉冉,谢鹏程,丁玉梅,等.新型扭转元件塑化过程数值模拟[J].塑料,2016,45(5):9-13.
[15] WEI J,CHEN D,ZHOU D,et al. Influence of screw rotors tip angle on mixing performance for one novel twin-screw kneader[J]. Polymer(Korea),2015,39(3):441-452.
[16]梁继举,李翱.热熔挤出中药物活性组分混合过程数值模拟研究[J].中国塑料,2017,31(6):84-89.
[2]唐锦荣. MuCell微发泡注塑成型技术应用[J].国外塑料,2011,29(4):60-61.
[3]赵惠英.微发泡注射成型[J].国外塑料,2004,22(5):49-50.
[4]何亚东.聚合物微发泡材料制备技术应用研究进展[J].塑料,2004,33(5):9-15.
[5] HEIM H. Specialized injection molding techniques[M]. New York:William Andrew,2016:53-106.
[6]翟明,陈建平.微孔泡沫塑料的制备工艺与设备[J].橡塑技术与装备,2016,42(10):44-45.
[7] GAUB H. Profoam—cost-efficient process for manufacturing foamed lightweight parts[J]. Reinforced Plastics,2017,61(2):109-112.
[8]杨伟,武力军,李瑞文,等.物理微发泡微开模注塑成型技术[J].模具技术,2017,(4):52-58.
[9]余坚,何嘉松.超临界CO2技术制备微孔聚合物中的基本问题[J].中国科学:化学,2010,40(1):1-15.
[10] XU J.微孔塑料注射成型技术[M].张玉霞,王向东,译.北京:机械工业出版社,2013:229-230.
[11]北京化工大学.聚合物熔体微积分强化传热与混炼塑化挤出机:中国,CN103753793A[P]. 2014-04-30.
[12]鉴冉冉,谢鹏程,杨卫民.基于场协同原理的聚合物塑化过程数值分析[J].工程热物理学报,2017,38(2):281-288.
[13] JIAN R,YANG W,CHENG L,et al. Numerical analysis of enhanced heat transfer by incorporating torsion elements in the homogenizing section of polymer plasticization with the field synergy principle[J].International Journal of Heat and Mass Transfer,2017,115,Part A:946-953.
[14]鉴冉冉,谢鹏程,丁玉梅,等.新型扭转元件塑化过程数值模拟[J].塑料,2016,45(5):9-13.
[15] WEI J,CHEN D,ZHOU D,et al. Influence of screw rotors tip angle on mixing performance for one novel twin-screw kneader[J]. Polymer(Korea),2015,39(3):441-452.
[16]梁继举,李翱.热熔挤出中药物活性组分混合过程数值模拟研究[J].中国塑料,2017,31(6):84-89.