Researchers atUniversiti Teknikal Malaysia Melaka（UTEM）开发了3D打印机，该打印机能够从回收的ABS产生更多的弹性零件。
或通过安装两个压电换能器dinary gantry Fused Filament Fabrication (FFF) 3D printer, the engineers have managed to develop a means of reversing some of the reduction in strength often exhibited by recycled ABS.
Given the efficacy of their design, which is capable of improving the compression strength of parts made from reused material by 59%, the team say it could help minimize the amount of environmentally-damaging filament that goes to landfill.
Improving FFF’s material efficiency
While 3D printing is often marketed as being more material-efficient than subtractive manufacturing technologies, it’s not without its own issues in this area. As any desktop 3D printer user will tell you, print errors can be expensive as well as time consuming, due to the amount of material they waste. Given that many of these plastics are wastefully disposed of, they’re also an environmental hazard.
One way that makers and manufacturers have attempted to improve the efficiency of their systems is via the recycling of ABS, a material that’s already popular among the 3D printing community. However, as highlighted by the UTeM team in their paper, “the mechanical properties of recycled ABS are markedly degraded,” and reusing the material can reduce its final strength after printing by up to 49%.
This weakening, which the researchers identified through their own recycled ABS testing, was found to be due to poor interlayer bonding. Such delamination can cause resulting materials internal damage, in a way that leads them to fail when 3D printed, thus making them an unappealing alternative to throwaway filaments.
转向超声振动
Having developed their own recycled material, by granulating used ABS before extruding it into a 1.75 mm filament, the UTeM researchers then proceeded to 3D print it into samples with a prototype piezoelectric transducer-fitted FFF machine, designed to use ultrasound vibration as a means of improving its stability.
尽管发现在230°C的喷嘴温度下产生的初始模型表现出表面缺陷，但工程师继续确定将此参数提高到270°C并降低打印速度纠正了这些问题。该小组还发现，在20 kHz频率下暴露于超声振动“大大改善了回收层的粘附”。
This proved the case when it came to improving the flexural strength and modulus of their printed objects, which were 43% and 53% higher than in unexposed parts respectively. The researchers’ results were later confirmed during tensile strength testing, in which materials treated at 20 kHz had a strength of 27.5 MPa, around 24% and 19% higher than those exposed to 10 kHz and those untreated entirely.
在最初的研究成功之后，研究人员计划将其设计开源。在这样做的过程中，该团队旨在使超声波传感器尽可能容易地增加超声波传感器，并帮助推动采用可回收的ABS作为常规一次性材料的更可行的替代方案。雷电竞app下载
“Overall, [our] approach is a viable option for the better use of printed materials and, with the aid of ultrasound vibration, it improves the mechanical properties of recycled ABS,” conclude the team in their paper. “Therefore, this study shows tremendous potential for sustainable management of ABS waste through recycling, otherwise an increasing burden on resource and landfill sites.”
Making waves in the 3D bioprinting sector
The UTeM team may have identified a polymer 3D printing application of ultrasound waves, but the technology is more conventionally used within 3D bioprinting. In March 2021, scientists at theUniversity of Bath和University of Bristol提出了一个acoustic energy driven bioprinting processwith tissue engineering potential.
The technology was reminiscent of that developed by researchers atNorth Carolina State Universityaround two years earlier, which involvedusing ultrasound to arrange cells in 3D bioprintinggels. In their paper, the team suggested the technique could improve the fidelity of artificial tissues compared to their biological equivalents, in a way that enables them to address wound treatment applications.
Elsewhere,Concordia University科学家还发现了deploying ultrasound in polymer 3D printing。从本质上讲，团队的技术涉及使用声波在微小的腔体中产生超声反应，并生产出使用现有技术无法实现的复杂零件。
The researchers’ findings are detailed in their paper titled “与超声振动集成的开源FDM打印机印刷的回收ABS的机械性能的研究。”该研究由Maidin S，Ting K. H.和Sim Y. Y.合着。
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Featured image shows the researchers’ experimental ultrasound 3D printing setup. Photo via UTeM.
