Bochnia Jerzy
Faculty of Mechatronics and Mechanical Engineering, Kielce University of Technology, 25-314 Kielce, Poland.
Materials (Basel). 2023 Jan 1;16(1):400. doi: 10.3390/ma16010400.
Additive manufacturing is being increasingly used both for rapid prototyping as well as the fabrication of finished components. It is important to determine how the properties of 3D printed materials change over time and how they affect the durability and usability of products. The aim of the research presented in this article was to find out what influence the natural aging period had on the mechanical properties, especially the tensile strength and modulus of elasticity, of specimens made from the selected photocurable resins using the PolyJet Matrix (PJM) technology. The tests involved determining the tensile strength and modulus of elasticity of specimens fabricated in 2013 and 2014 using two types of photosensitive resins, i.e., FullCure 720 and VeroWhite, respectively. Some of the specimens were stored under laboratory conditions until July 2022 and then tested using a universal testing machine. The experimental data obtained in 2022 for the naturally aged models were compared with those reported for the as-printed specimens. One of the main findings of this study was that the tensile strength and modulus of elasticity of the naturally aged specimens were largely dependent on the printing direction (model orientation on the build tray). The test results show that aging generally decreased the tensile strength of the specimens. In one case, however, an increase in this property was observed. For the X and Y printing directions, declined by 27.1% and 30.7%, respectively. For the Z direction, a decrease of only 5.5% was reported, for Full Cure 720. The modulus of elasticity of the models tested in 2022 differed considerably from that reported for the as-printed objects. Higher values of the modulus of elasticity implied that the material stiffness increased over time, and this is a common phenomenon in polymers. Interesting results were obtained for VeroWhite specimens. The modulus of elasticity decreased significantly by 25.1% and 42.4% for the specimens printed in the X and Z directions, respectively. However, for the models built in the Y direction, it increased by 27.4%. The experimental data may be of significance to users of products manufactured using the PJM method as well as to researchers dealing with the durability and reliability of such materials.
增材制造越来越多地用于快速成型以及成品部件的制造。确定3D打印材料的性能如何随时间变化以及它们如何影响产品的耐久性和可用性非常重要。本文所介绍研究的目的是找出自然老化期对使用PolyJet Matrix（PJM）技术由选定的光固化树脂制成的试样的机械性能，特别是拉伸强度和弹性模量有何影响。测试包括确定分别于2013年和2014年使用两种光敏树脂FullCure 720和VeroWhite制造的试样的拉伸强度和弹性模量。一些试样在实验室条件下保存至2022年7月，然后使用万能试验机进行测试。将2022年针对自然老化模型获得的实验数据与已报道的刚打印出的试样的数据进行比较。本研究的主要发现之一是，自然老化试样的拉伸强度和弹性模量在很大程度上取决于打印方向（构建托盘上模型的方向）。测试结果表明，老化通常会降低试样的拉伸强度。然而，在一种情况下，观察到这一性能有所增加。对于X和Y打印方向，拉伸强度分别下降了27.1%和30.7%。对于Z方向，Full Cure 720仅下降了5.5%。2022年测试的模型的弹性模量与已报道的刚打印出的物体的弹性模量有很大差异。弹性模量较高的值意味着材料刚度随时间增加，这在聚合物中是一种常见现象。VeroWhite试样获得了有趣的结果。在X和Z方向打印的试样的弹性模量分别显著下降了25.1%和42.4%。然而，对于在Y方向构建的模型，其弹性模量增加了27.4%。实验数据可能对使用PJM方法制造产品的用户以及研究此类材料耐久性和可靠性的研究人员具有重要意义。
