The Influence of Polylactic Acid Filament Moisture Content on Dust Emissions in 3D Printing Process

Area of Science:

• Additive Manufacturing
• Environmental Science
• Materials Science

Background:

• 3D printing, specifically incremental manufacturing using polylactic acid (PLA), is a growing technology.
• Concerns exist regarding airborne particulate matter (PM) emissions during 3D printing processes.
• The impact of filament properties, such as moisture content, on these emissions requires further investigation.

Purpose of the Study:

• To investigate the effect of varying moisture content in PLA filaments on dust emissions during 3D printing.
• To quantify particulate matter (PM1, PM2.5, PM10) concentrations associated with different filament humidity levels.
• To assess the relationship between filament moisture and the variability of dust emissions.

Main Methods:

• Utilized a customized chamber setup with a standard 3D printer for controlled testing.
• Employed Plantower PMS3003 sensors to monitor PM1, PM2.5, and PM10 concentrations in real-time.
• Tested PLA filaments with three distinct moisture content levels: 0.18% (dry), 0.61% (slightly humid), and 0.83% (very humid).

Main Results:

• Increased filament moisture content significantly correlated with higher dust emissions.
• Dry filaments (0.18% humidity) showed average emissions from 159 to 378 µg/m³.
• Humid filaments (0.61% and 0.83%) exhibited substantially higher and more variable emissions, with some measurements exceeding 1600 µg/m³ and standard deviations up to 198 µg/m³.

Conclusions:

• Filament moisture content is a critical factor influencing dust emissions in PLA 3D printing.
• Higher humidity leads to increased particulate matter generation and greater emission instability.
• Findings suggest potential health risks associated with printing humid PLA filaments, necessitating mitigation strategies.