Abstract Material Extrusion (ME), which is a type of Additive Manufacturing (AM), has become widely popular in the manufacturing world. However, the evolution of a material's temperature in this relatively new manufacturing method, which plays an important role in the polymer crystallinity, is not yet well researched. Next to voids, interlayer adhesion and surface roughness, the degree of crystallinity strongly determines the quality of printed products. Hence, a thorough and deep understanding of crystallinity in ME is essential for the improvement of the parts printed. In this paper, a primary generic model is proposed to predict the temperature evolution and crystal growth of printed polymer materials. The temperature evolution was developed based on the two-dimensional domain discretisation method and the crystal growth was simulated via the Hoffman-Lauritzen theory. In the simulation, key parameters have been taken into consideration, such as the printing speed, thermal convection coefficient, thermal contact conductance with the platform, nozzle diameter and latent heat in crystallisation. Then, a single-line printing scenario was tested to verify the accuracy of the model. A comparison of the model predictions with the experimental results showed only of up to 3.8 °C deviations which is a 2% of maximum percentage mismatch from the full scale reading.

中文翻译：

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通过挤出进行聚合物材料 3D 打印过程中温度和晶体生长演变的预测

摘要 材料挤出 (ME) 是一种增材制造 (AM)，已在制造业中广泛流行。然而，在这种相对较新的制造方法中，材料温度的演变对聚合物结晶度起着重要作用，尚未得到很好的研究。除了空隙、层间附着力和表面粗糙度之外，结晶度在很大程度上决定了印刷产品的质量。因此，彻底而深入地了解 ME 中的结晶度对于改进打印部件至关重要。在本文中，提出了一种主要的通用模型来预测印刷聚合物材料的温度演变和晶体生长。温度演化是基于二维域离散化方法开发的，晶体生长是通过霍夫曼-劳里岑理论模拟的。在模拟中，考虑了关键参数，例如打印速度、热对流系数、与平台的热接触传导、喷嘴直径和结晶潜热。然后，测试了单行打印场景以验证模型的准确性。模型预测与实验结果的比较显示仅高达 3.8 °C 的偏差，这是与全刻度读数最大百分比不匹配的 2%。与平台的热接触传导、喷嘴直径和结晶潜热。然后，测试了单行打印场景以验证模型的准确性。模型预测与实验结果的比较显示仅高达 3.8 °C 的偏差，这是与全刻度读数最大百分比不匹配的 2%。与平台的热接触传导、喷嘴直径和结晶潜热。然后，测试了单行打印场景以验证模型的准确性。模型预测与实验结果的比较显示仅高达 3.8 °C 的偏差，这是与全刻度读数最大百分比不匹配的 2%。