University of Tampa , 401 W. Kennedy Boulevard , Tampa , Florida 33606 , United States.
Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , P.O. Box 2008 MS-6487, Oak Ridge , Tennessee 37831-6487 , United States.
Environ Sci Technol. 2019 Aug 20;53(16):9656-9663. doi: 10.1021/acs.est.9b02818. Epub 2019 Aug 8.
An eddy diffusion model using data from a desktop three-dimensioanl (3D) printer was developed under laboratory conditions and then coupled with Monte Carlo analysis to estimate the potential range of particulate concentrations in and around various industrial-size 3D printers, in this case large additive manufacturing processes using acrylonitrile-butadiene-styrene polymer feedstock. The model employed mass emission estimates determined from thermal gravimetric analysis and printer enclosure particle loss rates. Other model inputs included ranging terms for extrusion rate, temperature, print time, source-to-receiver distance, printer positions, particle size fraction, and environmental diffusivity estimates based on air changes per hour. Monte Carlo analysis bracketed measured environmental particulate concentrations associated with large-scale additive manufacturing processes (3D printing). Statistically, there was no difference between the average near-field particle concentrations measured and that of the model-derived average. However, the model began to vary more statistically, if not practically, from air-monitoring results in the far field. Diffusivity and extrusion rate emerged as the two most important variables in predicting environmental concentrations. This model can be used to estimate air concentrations over a range of varying conditions, such as one might employ in a "what if" type of evaluation to estimate employee exposure, for example, as a compliance effort with OSHA standard 29 CFR Part 1910.132, requiring a formal hazard assessment for work environments as a "before exposure" effort to determine if respiratory protection is needed.
开发了一种使用台式三维（3D）打印机数据的涡流扩散模型，然后将其与蒙特卡罗分析相结合，以估计各种工业尺寸 3D 打印机（在此情况下，是使用丙烯腈-丁二烯-苯乙烯聚合物原料的大型增材制造工艺）内外的颗粒浓度的潜在范围。该模型采用了热重分析确定的质量排放估算值和打印机外壳颗粒损失率。其他模型输入包括挤出速率、温度、打印时间、源到接收器距离、打印机位置、颗粒大小分数和基于每小时空气交换量的环境扩散率估算值。蒙特卡罗分析围绕与大规模增材制造工艺（3D 打印）相关的环境颗粒浓度进行测量。从统计学上讲，测量的近场颗粒浓度平均值与模型得出的平均值之间没有差异。但是，如果不是实际情况，模型在远场的空气监测结果中开始呈现出更明显的统计学差异。扩散率和挤出速率成为预测环境浓度的两个最重要的变量。该模型可用于在各种变化条件下估算空气浓度，例如在“假设”类型的评估中可能会使用该模型来估算员工暴露情况，例如作为 OSHA 标准 29 CFR 第 1910.132 章的合规努力，该标准要求对工作环境进行正式的危害评估，作为“暴露前”努力，以确定是否需要呼吸保护。
