基于动态成型过程的强化分散混炼方法

介绍了基于动态成型过程强化分散混炼的方法以及实现这些方法的动态混炼挤出机的结构及工作原理。这种低能耗强混炼技术包括在单螺杆上增设差动混炼单元、增加物料沿程反馈螺杆以及采用三螺杆劫态混炼挤出机等。     

单螺杆挤出机中双组分物料的优化混炼对比

一般而言,单螺杆挤出机的混炼和排气功效比不上双螺杆挤出机。人们已经了解到,能否形成多点拉伸流动场是影响混炼效果好坏的关键所在。尤其是逆向拉伸流动场对分散混炼而言,可形成高临界剪切应力,所以说,逆向拉伸流动场对分散混炼过程是有益的。     

聚合物单螺杆挤出机混炼技术表征的研究

根据单螺杆挤出机的聚合物挤出加工过程的混炼特性，提出一种新的形变混炼评定指标，并且结合常规单螺杆挤出机进行了计算分析，同时还与其它一些方法进行了比较。     

单螺杆挤出机混炼效果研究

作者研究了具有混炼头的不同形式的单螺杆挤出机的混炼效果。结论对单螺杆挤出机的设计和应用具有指导意义。     

聚合物单螺杆挤出机混炼过程表征的研究

根据单螺杆挤出机在聚合物挤出加工过程的混炼特性 ,提出一种新的形变混炼评定指标 ,并且结合常规单螺杆挤出机进行了计算分析 ,同时还与其它一些方法进行了比较     

聚合物共混改性混炼挤出设备的探讨

探讨了聚合物共混改性的基本理论和聚合物混炼挤出设备的发展历程。重点从结构原理、性能及应用等方面对单螺杆挤出机、双螺杆挤出机以及电磁动态混炼挤出机进行了分析，并探讨了聚合物混炼挤出设备的发展方向。     

三维混炼:单螺杆配混有序混炼装置

正一个多世纪以来,众所周知,相比双螺杆挤出机,单螺杆挤出机(SSE)属于性能较差的混炼设备。最常见的双螺杆挤出机是啮合型同向旋转双螺杆(CRTS)挤出机。混炼可视为分散(即破碎成更小的单元)或者分布(在空间有序分布)混炼。SSE分布和分散混炼的效果都极差。20世纪后期,人们发现CRTS成功的主要原因之一是熔体在啮合区的伸长。被拉进两个螺杆间的一些熔体,就像橡皮筋一样可以在两端轻而     

往复式单螺杆混炼挤出机应用良好

经过实践检验，中国首台终炼胶混炼挤出机连续生产线在德国哈默市MDS公司应用取得成功，产品质量符合德国行业标准。设备主机往复式单螺杆混炼挤出机由江苏新达科技有限公司生产，弥补了普通单螺杆及双螺杆挤出机只能对一薄层物料进行剪切的缺陷。采用独特的运转方式，物料在螺块与销钉之间被剪切，并且被往复输送。     

双螺杆结构改善泡沫胶的预混炼

传统的PE和PS的物理起泡法是在两个前后排列安装的单螺杆挤出机上完成的。但Berstorff公司称ZE/KE Schaumtandex组合具有较高的挤出效率，其第一段混炼和塑化挤出机由双螺杆挤出装置替代。 Berstorff称，这种组合的使用可同时为双螺杆挤出机带来良好混炼能力和单螺杆挤出机极佳的冷却能力。 双螺杆结构满足了因市场原材料不断增加而致的混炼量增加的要求，且更适用于产量在750gk/h以上泡沫胶的混炼。与单螺杆挤出机相比，双螺杆具有较好的进料能力和较高的尺寸/产量比。此外，随着今后产量的增加，双螺杆机筒和螺杆的标准设计可能使其…     

单螺杆往复阻尼式混炼挤出机特性分析

本文着重讨论了单螺杆往复经式混炼挤出机的结构原理、运动分析和混炼原理，从理论上论证了这种机型的混炼效果及其优越性。     

离散单元法模拟分散混合的现状

分散混合在聚合物混合与复合、食品加工、胶体分散等工艺工程中起着重要作用,然而对于分散混合的机理和动态细节的认识尚浅。目前,离散元法被许多研究者用于模拟分散混合的过程,研究实践表明该方法是分析分散混合过程的有效工具。介绍了离散元法的概况,着重阐述了分散混合过程中各种力学模型的建立,概述了离散元法在分散混合中的应用现状,讨论了离散元用于研究分散混合时尚需解决的问题。     

双转子连续混炼机混沌型转子混合性能的研究

在提出一种新型混沌型转子结构的基础上,运用Polyflow软件对其混炼过程进行三维非牛顿等温模拟,并借助于粒子示踪法对物料所经历的流场特性进行统计学分析;分析了转子结构和工艺参数对转子混合性能的影响,同时通过共混改性实验,对转子的混合效果进行了评估和表征。结果表明,高混沌型转子的分布混合能力有较大的提高,同时保持着良好的分散混合能力;混沌型转子制备的复合材料力学性能优于经典转子;转子转速的提高可以增强混沌转子的分散及分布混合能力,适当的加料速率是保证取得较好混合效果的关键因素。     

双转子连续混炼机混炼段分散混合效率的研究

利用有限元分析软件Polyflow对自行设计的ECM30型双转子连续混炼机转子的混炼过程作了三维等温流场分析,借助于剪应力和混合指数对转子的分散混合效率进行了分析研究;讨论了不同的操作工艺对分散混合效率的影响。该数值模拟的结果将有助于针对不同的聚合物采用不同的混炼工艺,使得聚合物在转子中的混合达到最优化。     

注射机中腔穴传递式混合器的结构与混合机理

介绍了注射机中腔穴传递式混合器(CTM)在注塑模塑过程中的混合机理及混合特性，并评述了该类混合器的分散功能和混合效果。     

Analytical and Experimental Evaluation of Dispersive Mixing Performance of Special Rotor Segments in a Corotating Twin-Screw Extruder

An intermeshing corotating twin-screw extruder is often used for producing polymer composites. In this study, we discussed mixing performance of special rotor segments in molten zone. These rotor segments have several tip clearances for achievement of self-cleaning and effective mixing, and these are named various clearance mixing technology. We studied about dispersive mixing performance of configuration, which consists of various clearance mixing technologys (various clearance mixing technology configuration) using numerical analyses and experiments. For the analytical evaluation of mixing performance, we have adopted a particle tracking method. As evaluation indices of dispersive mixing performance, we focused on following three values (1) maximum value in a history of first principal stress of each particle, (2) time-integrated shear rate of each particle, and (3) time-integrated first principal stress of each particle. And we made the probability distributions of the indices. We adopted weighted probability as approximation of volume probability in each region. The results were compared with those of kneading disk segments configuration (kneading disk configuration). Furthermore, we validated the accuracy of the analytical evaluation by performing experiments under same conditions as those of numerical analyses. For the experimental evaluation of mixing performance, we used twin-screw extruder. Polypropylene was selected as suspending media. And CaCO₃ was selected as filler. To compare just the mixing performance of various clearance mixing technology configuration with that of kneading disk configuration, side feeding and screw configuration which had third mixing segments zone were adopted. From the experimental result, it is found that various clearance mixing technology configuration dispersed better than kneading disk configuration. And from the comparison between the experimental evaluation and the analytical evaluation, it is found that the first principal stress is more appropriate for evaluation index of dispersive mixing. Finally, it can be mentioned that various clearance mixing technology configuration has better mixing performance than kneading disk configuration, and large stress is important for dispersive mixing.     

双转子连续混炼机不同转子元件混合性能的对比研究

在普通转子的基础上设计了开槽螺棱转子和阶梯型螺棱转子,并借助聚合物加工分析软件 Polyflow分别对3种转子元件的混炼段进行了数值模拟,并对其混合性能进行了对比分析。结果表明,3种转子元件中,开槽螺棱转子的分散混合能力和分布混合能力最强,阶梯型螺棱转子的分散混合能力最差,其分布混合能力优于普通转子,但次于开槽螺棱转子;在分散混合方面,相对于普通转子和开槽螺棱转子,阶梯型螺棱转子对物料的分散能力更加依赖于拉伸作用。     

固体推进剂固相组分的混合研究

研究了含固体组分的两相体系固体推进剂混合过程的特点。用固体组分的浓度、粒径及其分布等参量研究分析了改性双基推进剂代料的混合特点。根据实验结果，认为改性双基推进剂的混合过程属分散混合。固体推进剂的性能将取决于分散混合后固体颗粒的尺寸。     

PE-HD/炭黑在捏合块元件内分散混合的数值模拟研究

使用Polyflow软件,计算了3种捏合块元件内高密度聚乙烯（PE-HD）熔体的三维拟稳态流场。引入炭黑在聚合物熔体中的分散数学模型,计算了不同捏合块中炭黑聚集体的粒径分布,比较了3种捏合块流道内炭黑在PE-HD中的分散混合效果。数值结果表明,捏合盘厚度大的捏合块,剪切拉伸作用较强,分散混合能力较强。     

Flow patterns and mixing mechanisms in the screw mixing element of a co‐rotating twin‐screw extruder

Non‐Newtonian and non‐isothermal flow simulations based on 3‐D FEM were applied to a special and conventional elements of a twin‐screw extruder. The screw mixing element (SME), a kind of special element, was a distributive mixing promoter consisting of a standard screw profile with slots cut across the flight tip to increase leakage flow. The full flight screw (FF) and the kneading block (KB) were examined as conventional elements in order to contrast the mixing behavior with the SME. The accuracy of numerical results was verified by experimentally measuring pressure and temperature. Additionally, marker particle tracking analysis was carried out to evaluate the distributive and dispersive mixing. Using the above analyses, the following results were obtained: The pumping capability of the SME was smaller than that of the FF and was the same as for the KB. The SME suppressed heat generation and showed the lowest temperature distribution of the three elements. For distributive mixing, the SME showed the best performance judging from the mixing coefficient G, residence time distribution, and area stretch distribution based on a laminar mixing mechanism. A higher rotational speed achieved better distributive mixing performance. For dispersive mixing defined by stress distribution, the SME showed the second best performance next to the KB. It also showed better dispersive mixing performance with increasing rotational speed. The SME had the advantages of low heat generation and good distributive mixing.