往复式单螺杆销钉挤出机往复运动传动机理与混炼性能关系的研究

对比了几种不同的往复式单螺杆销钉挤出机传动系统的传动机理,并在此基础上设计其对应的混合元件。利用Polyflow软件对混合元件内物料的流动和混合过程进行了模拟,分析了流场内的压力分布、剪切应力分布、物料停留时间和加工过程中物料经历的最大剪切应力。结果表明,采用摇摆箱传动系统时,流场内的剪切应力、温升和压力差较低,而轮系传动系统可实现单次旋转多次往复驱动模式,并且机械结构更具可靠性。     

单螺杆挤出机螺杆参数的计算

本文对普通三段式螺杆的设计提出了有关参数的计算方法。以聚合物的热物理参数、流变学参数为据，以例题形式对深延比、拖曳流、剪切速率、剪切应力、比能耗、混合度、停留时间、料温升高进行了大量的计算，并得出了最佳的设计效果。     

一种新型单螺杆挤出机

正本实用新型公开了一种新型单螺杆挤出机,包括螺杆、底座和挤出筒,螺杆设置在挤出筒内部,挤出筒设置在底座表面,挤出筒顶端安装有进料筒,进料筒内部设置有阻挡板,阻挡板侧面均匀设置有若干个出料槽,进料筒内部设置有搅拌轴,搅拌轴表面连接有若干个搅拌叶组,挤出筒表面设置有加热管,座     

一种锥形单螺杆塑料挤出机

本文简要介绍了一种最新的专利技术：一种锥形单螺杆塑料挤出机(专利号：ZL01261392．4)的结构特征、性能特点和应用前景。     

一种单螺杆塑料挤出机专用螺杆

<正>本实用新型公开了一种单螺杆塑料挤出机专用螺杆,包括螺杆主体,螺杆主体上设置有螺旋叶,螺杆主体的一端安装有轴杆,轴杆上安装有轴套,轴杆的一端安装有螺纹杆,螺纹杆上安装有传动齿轮,螺纹杆的一端安装有连接套,连接套的一端安装有接头,接头的内侧安装有镶嵌头,镶嵌头的一端安装有弹簧。本实用新型的螺杆主体的一端安装有轴杆,且在轴杆     

单螺杆挤出机的温度控制

在单螺杆挤出机多级加热及喂料温度的控制中,采用了高智能的RKC型温控仪,并通过一次比例、积分和微分调节(PID)自整定及偏差值修补,实现了精确地温度控制     

聚醚醚酮单螺杆挤出机的设计

针对聚醚醚酮材料的工艺特点,本文重点介绍了聚醚醚酮单螺杆挤出机的结构设计,该挤出机在聚醚醚酮生产中应用情况良好,具有广阔的市场前景.     

一种冲压式反应挤出机

一种冲压式反应挤出机，由往复运动部分、物料压入部分、L型止回流道、反应控制部分和成型控制部分组成。本实用新型可用于熔体流动速率极低的聚合物反应成型加工或熔体不易流动聚合物的成型加工。简化了止回结构，可控制反应条件，可以方便调整管材壁厚并具有特殊结构锁住热收缩膜以提高管材内壁光洁度。改进了上下往复运动精度，改进了加热器排列方式以提高温度控制精度，增设反应控制流道控制聚合物交联反应时间和压力（专利号ZL03270917．X）。     

单螺杆挤出机的混合及应用

本文分析了单螺杆挤出机的分散和分布混合能力,得出了单螺杆挤出机的适用混合类型。对比了Maddock、Pineapple、Twente以及CTM混合元件的性能。加装混合元件以后,单螺杆挤出机的分布混合效果得到很大提高;但在分散混合上,除颜料与聚烯烃外,效果尚不理想。     

销钉机筒橡胶挤出机内胶料三维剪切效果模拟

采用流体力学计算软件Fluent,在对销钉机筒冷喂料挤出机熔融段和输送段的胶料进行三维流动数值模拟的基础上,考察螺杆转速、反向压差、销钉数量和销钉排间距对单位质量流量的平均体积剪切速率(χ)和剪切速率均方差(S)的影响.结果表明,χ适宜作为评判剪切效果的参数,螺杆转速是影响剪切效果的显著因素;在螺杆转速高于20 r·min-1时,χ的变化具有规律性,S的变化趋势与小于20 r·min-1时相反.     

利用往复扰动螺棱强化单螺杆挤出机内混合模拟表征

提出了采用副螺棱轴向往复运动提高单螺杆挤出机混合的结构并建立了相应的数学模型。对挤出机内牛顿流体三维周期性流动和混合过程进行了数值模拟。采用有限体积方法,变量分布采用交错网格,副螺棱的周期性运动边界通过叠加网格方式实现。采用4阶Runge-Kutta方法实现流体追踪计算,得到了示踪剂界面增长及累积停留时间分布。采用Poincaré 截面揭示混沌混合存在的区域,证实了副螺棱往复运动能够产生混沌混合效应提高螺槽内的混合效果,与其位置固定时相比,缩短了平均停留时间,停留时间分布变窄。作为对比,同时分析了常规的副螺棱位置固定的单螺杆挤出机内的相应混合行为。     

Randcastle develops single screw compounding extruder

Randcastle Extrusion Systems, Inc. has developed a new compounding extruder. The company says that the Taskmaster is a single screw extruder that can compound and devolitilize. The Taskmaster is claimed to take single screw extruders into applications that were previously only possible with twin screw extruders. The prototype is a marked departure from Randcastle's vertical line of extruders with its first entry into the traditional horizontal extruder market.This is a short news story only. Visit www.addcomp.com for the latest additives and compounding industry news     

Mixing studies in the single screw extruder

Laminar mixing in a single screw extruder between two miscible liquids is considered. Studies are presented which examine the mixing performance in single screw extruders with mixing sections, variable geometry screws, and multi-viscosity mixtures. Model extruders, set up on engine lathes, were used to mix colored silicone rubber which eventually cured in the screw channel. The cured silicone was then removed and sliced to measure the mixing. Results show mixing as a function of both down channel location and total average strain. For the mixing section study, results support the theory of interfacial area reorientation as the key mechanism in mixing section performance. Increasing viscosity ratio for the multi-viscosity study showed a decrease in mixing rate.     

单螺杆挤出机混合装置与混合机理研究的新进展

由于单螺杆的简单、低成本等众多优点，对单螺杆挤出机不断加强研究。近年由于CRD混合结构的推出，其在混合效果方面获得一定的新进展。本文概述了单螺杆挤出机混合装置的历史发展过程，从其混合功能的机理演变，提出拉伸混合应作为适用与高效的混合研究发展方向。     

Optimisation of silane grafting in single screw extruder

Abstract

Reactive extrusion is an attractive means of polymer processing since the shaping and reaction takes place in a single operation. Silane grafting of low density polyethylene has been achieved in a single screw extruder. The optimum conditions for silane grafting, i.e. temperature, shear rate, and silane and dicumyl peroxide concentrations, were determined on a torque rheometer and extrusion was then performed under optimum conditions. The study shows that an optimum low level of grafting/crosslinking can be introduced into polyethylene during extrusion for better mechanical behaviour and/or thermal stability without aecting the processability.     

Reactive processing of polyethylenes on a single screw extruder

The modification of low density polyethylene, linear low density polyethylene, and their blend by dicumyl peroxide at the time of the extrusion on a single screw extruder is reported. The study shows that the optimum conditions of modification can be determined on a torque rheometer and these can then be applied for actual extrusion. A low level of crosslinking can be introduced by reactive extrusion for improving the heat stability without adversely affecting the processing behavior. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2545–2549, 2001     

Residence time distribution in a real single screw extruder

The residence time distribution in an industrial single screw extruder was investigated experimentally in the case of melt and plasticating extrusion. The investigations performed proved that the extrusion parameters influence strongly the residence time distribution in the extruder. It was found that the resistance to flow through the die-head of the extruder is very important from this point of view, as well as other parameters like rotational speed of the screw and the screw channel depth. Variation of these parameters can change the residence time distribution over a broad range between the extreme idealized cases of plug flow and flow with perfect mixing. In order to obtain quantitative dependences three moduli were used and a correlation equation was obtained. This equation enables an estimation of residence time distribution on the basis of experimental characteristics of the extruder and the actual extrusion parameters.     

螺杆挤压机混合能力的分析

分析螺槽中熔体的流动状态 ,运用加权平均总应变来评价螺杆挤压机的混合能力 ,进而提出提高混合能力的途径。对于单螺纹螺杆 ,稍长的计量段 ,稍浅的计量段螺槽及较高的螺杆转速 ,有利于混合作用 ;开发新型螺杆 ,如犁钉分流混合螺杆 ;研制高效混合型螺杆挤压机 ,如球窝型高效混合型螺杆挤压机     

Laboratory modular instrumented single screw extruder for optimisation of polymer processing

Abstract

A laboratory fully modular instrumented single screw extruder designed to gather information on the development along its axis of temperature, mixing, chemical conversion and/or morphology development of a given material is presented. Some of its capabilities are utilised to study the effect of operating conditions and of screw geometry, including conventional versus barrier profiles, on the evolution of the plasticating sequence of a low density polyethylene. Melting of an immiscible polymer blend (polyamide 6/polypropylene) is also investigated and a specific melting mechanism is proposed.     

羟基聚硅氧烷在单螺杆挤出机中的脱挥

研究了α,ω-二羟基聚二甲基硅氧烷在单螺杆挤出机中的脱挥,分析了影响脱挥效果的因素。结果表明,温度与真空度是影响脱挥效果的关键参数。温度升高,脱挥效果提高,最佳温度200～220℃;真空度升高,脱挥效果提高,但同时增加了冒料的可能性,适宜的真空度为24～28kPa。得出了实验范围内的挥发分最终质量分数与螺杆转速及进料流量的关联式。