Purpose

This paper aims to investigate effect of infill density, fabricated built orientation and dose of gamma radiation to mechanical tensile and compressive properties of polylactic acid (PLA) part fabricated by fused deposit modelling (FDM) technique for medical applications.

Design/methodology/approach

PLA specimens for tensile and compressive tests were fabricated using FDM machine. The specimens geometry and test method were referred to ASTM D638 and ASTM D695, respectively. Three orientations under consideration were flat, edge and upright, whereas the infill density ranged from 0 to 100%. The gamma radiation dose used to expose to specimens was 25 kGy. The collected data included stress and strain, which was used to find mechanical properties, i.e. yield strength, ultimate tensile strength (UTS), fracture strength, elongation at yield, elongation at UTS and elongation at break. The t-test was used to access the difference in mechanical properties.

Findings

Compressive mechanical properties is greater than tensile mechanical properties. Increasing number of layer parallel to loading direction and infill density, it enhances the material property. Upright presents the lowest mechanical property in tensile test, but greatest in compressive test. Upright orientation should not be used for part subjecting to tensile load. FDM is more proper for part subjecting to compressive load. FDM part requires undergoing gamma ray for sterilisation, the infill density no less than 70 and 60% should be selected for part subjecting to tensile and compressive load, respectively.

Originality/value

This study investigated all mechanical properties in both tension and compression as well as exposure to gamma radiation. The results can be applied in selection of FDM parameters for medical device manufacturing.

中文翻译：

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3DP工艺参数对医用聚乳酸部件力学性能的影响

目的

本文旨在研究填充密度、制造的构建方向和伽马辐射剂量对通过熔融沉积建模 (FDM) 技术制造的用于医疗应用的聚乳酸 (PLA) 部件的机械拉伸和压缩性能的影响。

设计/方法/方法

用于拉伸和压缩试验的 PLA 试样是使用 FDM 机器制造的。试样的几何形状和测试方法分别参考 ASTM D638 和 ASTM D695。正在考虑的三个方向是平面、边缘和直立，而填充密度范围从 0 到 100%。用于暴露于样本的伽马辐射剂量为 25 kGy。收集的数据包括应力和应变，用于寻找机械性能，即屈服强度、极限拉伸强度 (UTS)、断裂强度、屈服伸长率、UTS 伸​​长率和断裂伸长率。所述吨-test被用于访问在机械性质的差异。

发现

压缩力学性能大于拉伸力学性能。增加平行于加载方向的层数和填充密度，它增强了材料性能。直立在拉伸试验中表现出最低的机械性能，但在压缩试验中表现出最大。对于承受拉伸载荷的部件，不应使用直立定向。FDM 更适合承受压缩载荷的部分。FDM部件需要进行伽马射线灭菌，承受拉压载荷的部件应分别选择不小于70%和60%的填充密度。

原创性/价值

该研究调查了拉伸和压缩以及暴露于伽马辐射的所有机械性能。结果可用于医疗器械制造的 FDM 参数选择。