ABSTRACT

The rastering of discrete polymer filaments during Fused Filament Fabrication (FFF) results in the formation of voids between filaments, leading to poor properties and performance of the printed part. Minimising voids and improving filament-to-filament adhesion remains a key technological challenge for FFF. While mechanical rolling is commonly used in traditional manufacturing, its use in polymer 3D printing has not been explored much. This paper discusses the in situ compression of just-deposited filament using a roller that is integrated with the filament-dispensing nozzle. The roller travels with the filament nozzle, and compresses the filament immediately after deposition when it is still soft. The rolling process is characterised using high speed imaging and infrared (IR) thermography. The effects of compression force and roller temperature on print quality is investigated. In situ compression of the filaments is shown to result in 10X reduction in void formation. Tensile test results show 154% improvement in Ultimate Tensile Stress (UTS) and 417% improvement in material toughness due to compressive rolling. It is expected that implementation of the rolling technique discussed in this work may help print parts with improved properties and functionality.

摘要

熔融长丝制造（FFF）过程中离散聚合物长丝的光栅化导致长丝之间形成空隙，从而导致印刷部件的性能和性能变差。最小化空隙并改善细丝与细丝之间的附着力仍然是FFF的一项关键技术挑战。尽管机械轧制在传统制造中通常使用，但在聚合物3D打印中的使用却没有得到太多研究。本文讨论了原位使用与长丝分配喷嘴集成在一起的滚筒压缩刚沉积的长丝。辊与细丝喷嘴一起移动，并在沉积后仍较柔软的细丝紧紧压缩。轧制过程使用高速成像和红外（IR）热成像技术进行表征。研究了压缩力和辊温度对打印质量的影响。丝的原位压缩显示可导致空隙形成减少10倍。拉伸试验结果表明，由于压缩轧制，极限拉伸应力（UTS）改善了154％，材料韧性改善了417％。可以预期，这项工作中讨论的滚动技术的实施可以帮助打印具有改进的特性和功能的零件。