Assessing the dynamic extrusion-based 3D printing process for power-law fluid using numerical simulation

• Published in: Journal of food engineering Vol. 275; p. 109861
• Main Authors: Liu, Qiannan, Zhang, Nana, Wei, Wensong, Hu, Xiaojia, Tan, Yaoyao, Yu, Yongming, Deng, Yamin, Bi, Chao, Zhang, Liang, Zhang, Hong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2020
• Subjects: computer software; extrusion; Food 3D printing; mathematical models; Numerical simulation; potatoes; Printing characteristics; Rheological properties; temperature; three-dimensional printing; viscosity; Numerical simulation; Food 3D printing; Printing characteristics; Rheological properties
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2019.109861

Numerical simulation was applied for the extrusion process in an extrusion-based food 3D printing. The rheological properties of the materials and their printing characteristics were also investigated. In this work, the distributions of velocity, local shear rate, viscosity and pressure of the materials during the extrusion process were calculated by the POLYFLOW software, and the relationship among the rheological properties, flow field distribution and printing characteristics of the materials had been described. The results showed that the pressure distribution in the flow field was directly proportional to the consistency index (K), and the pressure decreased with the increase of the flow behavior index (n), but not linearly proportional to the n. When the potato granules were added, the K value of the material increased, the n value decreased, the viscosity and pressure levels in the flow field increased, and the printing of the products deteriorated. When temperature was elevated, the K value of the material decreased, the n value remained constant initially but increased later, the viscosity level in the flow field decreased, the pressure level decreased initially and then increased slightly, the printing process became smoother, and the accuracy of the printed product enhanced. For the experimental 3D printer, the Power-law fluid had better printing characteristics when the K value was between 1000 Pa•sn and 1800 Pa•sn and the n value was between 0.15 and 0.3. •Numerical simulation could reveal the dynamic extrusion process for 3D printing.•K and n values determine the flow field distribution.•K and n values change with fluid rheological properties, which in turn affect the printing characteristics.•Suitable range of K and n values for 3D printing was determined.