Väisänen Antti, Alonen Lauri, Ylönen Sampsa, Hyttinen Marko
Faculty of Science and Forestry, Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
School of Engineering and Technology, Savonia University of Applied Sciences, Kuopio, Finland.
J Occup Environ Hyg. 2022 Jun;19(6):381-393. doi: 10.1080/15459624.2022.2063879. Epub 2022 May 11.
Biocomposites (BCs) can be used as substitutes for unsustainable polymers in 3D printing, but their safety demands additional investigation as biological fillers may produce altered emissions during thermal processing. Commercial filament extruders can be used to produce custom feedstocks, but they are another source of airborne contaminants and demand further research. These knowledge gaps are targeted in this study. Volatile organic compound (VOC), carbonyl compound, ultrafine particle (UFP), and fine (PM) and coarse (PM) particle air concentrations were measured in this study as a filament extruder and a 3D printer were operated under an office environment using one PLA and four PLA-based BC feedstocks. Estimates of emission rates (ERs) for total VOCs (TVOC) and UFPs were also calculated. VOCs were analyzed with a GC-MS system, carbonyls were analyzed with an LC-MS/MS system, whereas real-time particle concentrations were monitored with continuously operating instruments. VOC concentrations were low throughout the experiment; TVOC ranged between 34-63 µg/m during filament extrusion and 41-56 µg/m during 3D printing, which represent calculated TVOC ERs of 2.6‒3.6 × 10 and 2.9‒3.6 × 10 µg/min. Corresponding cumulative carbonyls ranged between 60-91 and 190-253 µg/m. Lactide and miscellaneous acids and alcohols were the dominant VOCs, while acetone, 2-butanone, and formaldehyde were the dominant carbonyls. Terpenes contributed for ca. 20-40% of TVOC during BC processing. The average UFP levels produced by the filament extruder were 0.85 × 10-1.05 × 10 #/cm, while the 3D printer generated 6.05 × 10-2.09 × 10 #/cm particle levels. Corresponding particle ERs were 5.3 × 10-6.6 × 10 and 3.8 × 10-1.3 × 10 #/min. PM and PM particles were produced in the following average quantities; PM levels ranged between 0.2-2.2 µg/m, while PM levels were between 5-20 µg/m for all materials. The main difference between the pure PLA and BC feedstock emissions was terpenes, present during all BC extrusion processes. BCs are similar emission sources as pure plastics based on our findings, and a filament extruder produces contaminants at comparable or slightly lower levels in comparison to 3D printers.
生物复合材料（BCs）可作为3D打印中不可持续聚合物的替代品，但由于生物填料在热加工过程中可能产生变化的排放物，其安全性需要进一步研究。商用长丝挤出机可用于生产定制原料，但它们也是空气污染物的另一个来源，需要进一步研究。本研究针对这些知识空白展开。在办公室环境中，使用一种聚乳酸（PLA）和四种基于PLA的BC原料操作长丝挤出机和3D打印机时，测量了挥发性有机化合物（VOC）、羰基化合物、超细颗粒（UFP）以及细颗粒物（PM）和粗颗粒物（PM）的空气浓度。还计算了总挥发性有机化合物（TVOC）和超细颗粒物的排放率（ERs）估计值。使用气相色谱 - 质谱联用（GC - MS）系统分析挥发性有机化合物，使用液相色谱 - 串联质谱（LC - MS/MS）系统分析羰基化合物，而实时颗粒浓度则用连续运行的仪器进行监测。在整个实验过程中挥发性有机化合物浓度较低；长丝挤出过程中TVOC范围在34 - 63μg/m³之间，3D打印过程中在41 - 56μg/m³之间，这代表计算出的TVOC排放率为2.6 - 3.6×10和2.9 - 3.6×10μg/min。相应的累积羰基化合物范围在60 - 91和190 - 253μg/m³之间。丙交酯以及其他酸和醇是主要的挥发性有机化合物，而丙酮、2 - 丁酮和甲醛是主要的羰基化合物。在BC加工过程中，萜烯对TVOC的贡献约为20 - 40%。长丝挤出机产生的平均超细颗粒物水平为0.85×10 - 1.05×10⁶个/cm³，而3D打印机产生的颗粒水平为6.05×10⁵ - 2.09×10⁶个/cm³。相应的颗粒排放率为5.3×10⁵ - 6.6×10⁵和3.8×10⁴ - 1.3×10⁵个/min。PM和PM颗粒的平均产生量如下；PM水平在0.2 - 2.2μg/m³之间，而所有材料的PM水平在5 - 20μg/m³之间。纯PLA和BC原料排放之间的主要差异在于萜烯，在所有BC挤出过程中都存在。基于我们的研究结果，BCs与纯塑料是类似的排放源，并且与3D打印机相比，长丝挤出机产生的污染物水平相当或略低。
