SBIR Phase I: Optimization of Screw Geometry and Processing Conditions using Three-Dimensional Simulation of Melting and Melt Flow in Twin-Screw Extruders

这个小企业创新研究（SBIR）第一阶段项目将开发双螺杆挤出机两相流三维模拟软件。目前用于双螺杆挤出机设计的分析工具都是基于简化的一维或二维分析。然而，双螺杆挤出机中的两相流是复杂的；从这些简化的分析预测不能可靠地预测速度、压力和温度的分布。提出的两相流三维模拟软件将结合专有的构成理论，该理论考虑了聚合物的剪切粘度和伸长粘度。由于双螺杆挤出机啮合区域的流动是高度延伸的，因此所提出的软件的预测将比目前可用的忽略伸长粘度影响的工具更准确。提出的技术将加强对双螺杆挤出机中聚合物流动的理解，并将导致开发创新的螺杆型材。该软件的使用还将使包括塑料材料供应商、双螺杆挤出机制造商和塑料复合机在内的各种公司降低成本。

This Small Business Innovation Research (SBIR) Phase I project will develop software for three-dimensional simulation of the two-phase flow in a twin-screw extruder. Currently available analytical tools for design of twin-screw extruders are based upon simplified one-dimensional or two-dimensional analysis. However, the two-phase flow in twin-screw extruders is complex; and predictions from these simplified analyses cannot reliably predict the velocity, pressure and temperature distribution. The proposed software for three-dimensional simulation of the two-phase flow will incorporate a proprietary constitute theory that takes into account both the shear viscosity and the elongational viscosity of the polymer. Since the flow in intermeshing region of a twin-screw extruder is highly elongation dominated, the predictions from the proposed software will be more accurate than those from currently available tools that ignore the effect of elongational viscosity. The proposed technology will enhance the understanding of polymer flow in twin-screw extruders and will lead to developing innovative screw profiles. The use of this software will also enable various companies including plastic material suppliers, twin-screw extruder manufacturers and plastic compounders to cut costs.