【摘要】 聚酯高速纺丝宜采用具有混合功能的销钉螺杆.通过简单的模型实验,发现销钉的混合机理主要是属于层流混合中的剪切混合与伸长混合.根据实验观察结果,讨论了销钉混合均匀性与各种影响因素,并联系混合问题讨论了阻力消耗及热传递.更多还原

【Abstract】 The pin screw with mixing function have been used for PET high-speed spinning. Through a simple model experiment, mixing mechanism of the pin screw has been found. There are both laminar shear mixing and laminar elongation mixing in the channel of the pin screw. As a general case, shear mixing is main. The mixing efficiency is increased by the pin because both mixing actions happen simultaneously. It is more useful for high-speed spinning than a conventional screw. The experimental investigation demonstrates that mixing efficiency depends on pin geometry (e. g. diameter, intervals and numbers), and operating conditions (e. g. average volcity of melt flow), and materials properties (e. g. rheology). In general, if pin diameter and numbers are increased and intervals are decreased, the mixing efficiency will be increased. The power consumption depends on pin setting considerably. Friction resistance is increased while the pin diameter, melt flow rate, melt viscosity and density are increased. Also, the pin can improve heat transfer among the melt, benefit uniformity of the melt temperature and enhance thermal efficiency.更多还原