Abstract: In order to investigate the molding process of polymer at low temperature under vibration force field，a ball-screw-electromagnetism-dynamic extruder was manufactured and a model for this molding process was developed.The molding mechanism of polymer at low temperature was studied，and the energy source for polymer molding was depicted with the dissipation energy resulted from vibration，deformation and shearing.An expression for the density of energy transform was obtained.Experimental studies and calculation were used to investigate the effect of vibration parameters.The results reveal that the calculation values are in good agreement with the experimental data.The vibration force field decreases the temperature for polymer processing (up to 40℃)，reduces the energy consumption (more than 47%)，and improves the tensile strength of polymer product.This work can serve as the theoretical and technical basis for polymer processing and equipment design.

Key words: 聚合物, 挤出, 低温, 球型螺杆

摘要： 为了研究振动场作用下聚合物低温塑化成型过程，研制了一套球型螺杆电磁激振挤出装置，建立了振动场作用下聚合物低温塑化成型的物理模型，深入分析了振动场作用下聚合物低温塑化机理，然后从振动耗散能、聚合物变形能、摩擦热、剪切热等方面分析了聚合物塑化的能量来源，并通过数学推导得出了能量输送密度的数学表达式。最后使用球型螺杆电磁激振实验台和低密度聚乙烯（LDPE）进行实验和理论计算，实验结果与理论计算结果符合很好，并得出结论：振动场的引入可以降低聚合物的成型温度40℃以上、可以节约单位质量物料成型能耗47%以上，同时可以提高制品力学强度。本研究将会为聚合低温成型工艺和成型设备的研究提供可靠的理论基础。

关键词: 聚合物, 挤出, 低温, 球型螺杆