Material Characterization of Agricultural and Industrial Solutions and Melts in Extensional Processes

摘要 提案编号： CTS-9711109主要研究者：Bechtel，俄亥俄州 这是一个赠款，以表征材料的制造和农业过程中的纤维纺纱和喷雾。 这是以前研究的延伸，在以前的研究中，分析和计算机代码被创建并用于表征纤维纺丝和喷涂行为所需的材料特性的实验测量。 这些特性的准确表征，特别是动态表面张力，拉伸粘度，弛豫时间等，是理解和模拟这些过程的关键。 为了测量与纤维纺丝和喷涂工艺相关的流动特性，流变仪必须在相同的流动条件和历史以及相同的短时间尺度下测量处于适当状态的流体的特性。 主要研究人员现在建议将这项研究应用于与工业合作伙伴（Hoechst Celanese Corporation）和政府机构（美国农业部）开发的应用，这些应用由他们的需求和关注点定义，并具有明确的工程重点和回报。 由同事Kurt Koelling博士开发的新型流变仪将用于：（1）进行聚合物溶液的系统拉伸表征，采用在1中所示的技术，以在给定的本构假设内产生流体的最佳表征，并筛选一组建议的本构模型以选择最佳模型，（2）扩展表征技术以允许多个弛豫时间，（3）去除技术中的力测量的要求，（4）使装置适于新形成的表面的表面张力的动态测量（在毫秒的量级上），以及在更长的时间范围上，（5）将该方法扩展到非稳态和非等温行为，以及（6）表征细丝中取向的发展与流动的耦合。 与Koelling教授的合作将继续下去。

ABSTRACT Proposal Number: CTS-9711109 Principal Investigator: Bechtel, Ohio State This is a grant to characterize materials in the manufacturing and agricultural processes of fiber spinning and spraying. This is an extension of previous research in which analysis and computer codes were created and utilized in experimental measurements of the material properties necessary to characterize behavior in fiber spinning and spraying. Accurate characterization of these properties, specifically dynamic surface tension, elongational viscosity, relaxation times, and others, is critical to the understanding and modeling of these processes. To measure the flow properties relevant to fiber spinning and spraying processes, the rheometer must measure the properties of the fluid in the appropriate state, under the same flow conditions and history, and in the same short time scales. The principal investigators now propose to bring this research to bear on applications developed with an industrial partner (Hoechst Celanese Corporation) and a government agency (US Department of Agriculture), defined by their needs and concerns, and with clear engineering emphasis and payoff. A new rheometer, developed by a colleague, Dr. Kurt Koelling will be used to: (1) undertake a systematic elongational characterization of polymer solutions, employing the technique demonstrated in 1 both to produce the best characterization of a fluid within a given constitutive assumption, and to sift through a battery of proposed constitutive models to select the best model, (2) extend the characterization technique to allow for multiple relaxation times, (3) remove the requirement of a force measurement in the technique, (4) adapt the apparatus for the dynamic measurement of surface tension of newly formed surfaces (on the order of a millisecond), and, on a longer time frame, (5) extend the method to unsteady and non-isothermal behavior, and (6) characterize the coupling of the development of orientation in t he filament to flow. The collaboration with Prof. Koelling will continue.