Bembenek Michał, Kowalski Łukasz, Kosoń-Schab Agnieszka
Faculty of Mechanical Engineering and Robotics, AGH University of Science and Technology, A. Mickiewicza 30, 30-059 Kraków, Poland.
Polymers (Basel). 2022 Jun 16;14(12):2446. doi: 10.3390/polym14122446.
Fused deposition modeling (FDM) is one of the most accessible additive manufacturing (AM) technologies for processing polymeric materials. It allows processing most of thermoplastic polymers, with polyethylene terephthalate glycol-modified (PET-G) and polylactic acid (PLA). AM parts tend to display anisotropic behavior because of layer-by-layer fabrication and various technological parameters that can be set for 3D print, so it is hard to predict and analyze how the manufactured parts would behave under load. This research presents results of classic tensile strength tests performed on 57 PET-G specimens and 57 PLA specimens manufactured with varying technological parameters such as: printing temperature, print orientation, layer height, and infill percentage. Afterward, a comparative analysis is performed, proposing specific tensile strength (STS) as a benchmark to determine how 3D printed parts strength is varying due to beforementioned parameters, eliminating bias induced by varying weight of specimens. The biggest relative increase of UTS and the biggest relative decrease of STS was noted for variable infill percentage (increasing infill-PLA: 37.27% UTS increase and 30.41% STS decrease; PET-G: 24.42% UTS increase and 37.69% STS decrease). The biggest relative increase of STS between examined parameters was observed for both materials as the printing temperature was increased (27.53% for PLA and 12.69% for PET-G). Similar trends in STS changes were observed for both materials. Obtained data shows which FDM AM parameters are the most important to obtain the biggest UTS of manufactured parts, and those do not overlap with parameters needed to obtain optimal strength-to-weight ratio.
熔融沉积建模（FDM）是加工聚合物材料时最容易获得的增材制造（AM）技术之一。它能够加工大多数热塑性聚合物，如聚对苯二甲酸乙二醇酯改性（PET-G）和聚乳酸（PLA）。由于逐层制造以及可针对3D打印设置的各种工艺参数，增材制造部件往往表现出各向异性行为，因此很难预测和分析制造的部件在负载下的行为。本研究展示了对57个采用不同工艺参数制造的PET-G试样和57个PLA试样进行的经典拉伸强度测试结果，这些工艺参数包括：打印温度、打印方向、层高和填充率。随后，进行了对比分析，提出将比拉伸强度（STS）作为基准，以确定3D打印部件的强度如何因上述参数而变化，消除因试样重量变化引起的偏差。对于可变填充率，观察到极限抗拉强度（UTS）的最大相对增加和STS的最大相对降低（填充率增加时 - PLA：UTS增加37.27%，STS降低30.41%；PET-G：UTS增加24.42%，STS降低37.69%）。随着打印温度升高，两种材料在所研究的参数中均观察到STS的最大相对增加（PLA为27.53%，PET-G为12.69%）。两种材料在STS变化方面观察到类似趋势。获得的数据表明哪些FDM增材制造参数对于获得制造部件的最大UTS最为重要，并且这些参数与获得最佳强度重量比所需的参数并不重叠。
