In-line rheological monitoring of fused deposition modeling
In-line rheological monitoring of fused deposition modeling
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DOI：
10.1122/1.5054648
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发表时间：
2019-01-01
影响因子：
3.3
通讯作者：
Kazmer, David O.
中科院分区：
文献类型：
--
作者：
Coogan, Timothy J.;Kazmer, David O.
通过设计带有定制压力传感器和用于测量加工熔体温度的热电偶的改进喷嘴，首次将在线流变仪集成到熔融沉积建模打印机中。此外，通过计算步进电机脉冲以及来自定制灯丝编码器的脉冲来监测体积流量和剪切速率，以考虑灯丝滑移和跳过的电机步骤。描述了传感器的结合以及在线流变仪的设计和开发；并显示 3D 打印喷嘴内的压力、温度和粘度。通过分析两种聚合物材料：聚碳酸酯和高抗冲聚苯乙烯，对照传统的离线旋转流变学和毛细管流变学测量对在线流变仪进行了验证。在线流变仪考虑了各种流变校正，包括入口效应、非牛顿校正、剪切加热、压力效应和温度波动/不准确性。在应用最关键的校正后，在线和离线流变仪之间获得了极好的一致性，这些校正被发现是入口效应、非牛顿校正和温度误差。经过适当的校正后，在线流变仪可提供准确的粘度测量结果，可用于实时监控和过程控制。 (C) 2018 年作者。
An in-line rheometer has been incorporated into a fused deposition modeling printer for the first time by designing a modified nozzle with a custom pressure transducer and a thermocouple for measuring the processed melt temperature. Additionally, volumetric flow rates and shear rates were monitored by counting the stepper motor pulses as well as the pulses from a custom filament encoder to account for filament slippage and skipped motor steps. The incorporation of the sensors and the design and development of the in-line rheometer are described; and pressures, temperatures, and viscosities within the 3D printing nozzle are presented. The in-line rheometer was validated against traditional, off-line rotational rheology and capillary rheology measurements by analyzing two polymeric materials: polycarbonate and high-impact polystyrene. A variety of rheological corrections were considered for the in-line rheometer, including entrance effects, non-Newtonian corrections, shear heating, pressure effects, and temperature fluctuations/inaccuracies. Excellent agreement was obtained between the in-line and off-line rheometers after applying the most critical corrections, which were found to be entrance effects, non-Newtonian corrections, and temperature inaccuracies. After applying the appropriate corrections, the in-line rheometer provides an accurate viscosity measurement that can be used for real-time monitoring and process control. (C) 2018 Author(s).