Design of a low-cost, high-temperature inverted build environment to enable desktop-scale additive manufacturing of performance polymers
Design of a low-cost, high-temperature inverted build environment to enable desktop-scale additive manufacturing of performance polymers
复制标题
DOI：
10.1016/j.addma.2020.101111
复制
发表时间：
2020-05-01
影响因子：
11
通讯作者：
Williams, Christopher
中科院分区：
文献类型：
--
作者：
Zawaski, Callie;Williams, Christopher
熔丝制造（FFF）增材制造（AM）中的加热构建环境用于促进打印部件中的层结合，并减少挤出和环境之间的温差，从而减少收缩、残余应力和部件变形。通常需要能够保持高温（> 200摄氏度）的构建环境，以实现高玻璃化转变、高性能聚合物（如尼龙、PPSF和ULTEM）的高质量FFF打印。工业规模的AM系统能够打印这种聚合物，因为它们提供受控的高温打印环境;然而，机器成本通常超过100，000美元。现在有了高温打印机，而且价格较低;但是，成本仍然很高（大约30 000美元）。这些打印机中的许多使用床加热而不是受控的环境加热，这可能导致不均匀的传热和不一致的特性。以具有成本效益的方式为桌面级FFF系统提供高温环境的关键障碍是电气部件必须与超过100摄氏度的环境兼容、受到保护或从超过100摄氏度的环境中移除。为了能够以低成本和高质量实现高性能聚合物的桌面级FFF打印，作者提出了一种新颖的倒置FFF系统设计，可提供高达400摄氏度的构建环境。倒置配置有效地将系统电子器件与加热的构建环境隔离，这允许使用廉价的组件。在本文中，作者通过计算流体动力学模型分析验证了倒置设计概念。然后，通过比较在倒置桌面规模的FFF系统上打印的PPSF组件的强度，实验验证了该概念。
A heated build environment in Fused Filament Fabrication (FFF) additive manufacturing (AM) is used to promote layer bonding in printed parts and reduce the difference in temperature between the extrusion and environment decreasing the shrinkage, residual stresses, and part deformation. A build environment capable of maintaining a high-temperature (> 200 degrees C) is often required to enable high-quality FFF printing of high-glass-transition, high-performance polymers such as nylon, PPSF, and ULTEM. Industrial-scale AM systems are capable of printing such polymers, as they offer a controlled, high-temperature printing environment; however, the machine cost often exceeds > $100,000. High-temperature printers are now available and at lower costs; however, the cost is still expensive (similar to $30,000). Many of these printers use bed heating rather than controlled environment heating, which can lead to inhomogeneous heat transfer and inconsistent properties. The key barrier to offering high-temperature environments for desktop-scale FFF systems in a cost-effective manner is that the electrical components must be compatible with, protected from, or removed from environments exceeding 100 degrees C.To enable desktop-scale FFF printing of high-performance polymers at a low cost and high quality, the authors present a novel inverted FFF system design that provides a build environment of up to 400 degrees C. The inverted configuration effectively isolates the system electronics from the heated build environment, which allows for the use of inexpensive components. In this paper, the authors verify the inverted design concept analytically via a computational fluid dynamics model. The concept is then experimentally validated via a comparison of the strength of PPSF components printed on the inverted desktop-scale FFF system.