Challenges in 3D Printing: A Comprehensive Overview

11/1/23

Part 7 of the 9 Part Series will describe how 3D printing technology influenced the environment during its time.

3D printing has been a catalyst for sustainability, offering compelling reasons for companies to embrace additive manufacturing. Yet, amid its sustainable potential, it's essential to recognize that 3D printing is not without its ecological challenges. The foremost environmental concern in additive manufacturing pertains to waste management, encompassing issues related to failed and outdated prints, excess or used liquid resins, plastic powders, support materials, and byproducts from metal printing.

This chart depicts the energy consumption of a regular 3D printer. — Energy Consumption of a 3D Print

While exact data on the environmental impact of additive manufacturing remains scarce, the increasing accessibility of 3D printing has led to a surge in printed objects, resulting in a significant waste management issue. For instance, a survey by Filamentive revealed that as much as 8 million kilograms of 3D-printed plastic waste were generated in 2020, with a substantial portion ending up in landfills.

Complicating matters is the lack of industrywide recycling initiatives. Although polylactic acid (PLA), a popular 3D printing filament, is biodegradable, its composting properties necessitate industrial processing, making it unsuitable for typical consumer recycling facilities. The concept of a closed-loop material cycle remains largely aspirational, where printed parts are recycled into raw materials.

While a few companies produce plastic filaments from recycled waste, the mainstream adoption of such practices has been sluggish. For instance, Materialise's Blueprint PA12 material, which can be 100% reused, has faced limited commercial uptake. Some 3D printing techniques generate substantial waste, with up to 50% of powder going to waste, particularly in selective laser sintering.

GEARED FOR SUCCESS: FORD NOW OPERATES 3D PRINTERS AUTONOMOUSLY, INCREASING EFFICIENCY AND REDUCING COST — Ford Operating One of thier New 3D Printers

In response to these challenges, innovative solutions are emerging. Ford Motor Co. has initiated a program to repurpose 3D printing polymer powders and parts into raw materials for injection molding, effectively converting waste into functional auto parts. However, recycling metal in additive manufacturing poses unique challenges, especially in industries with strict metal quality requirements.

The energy consumption of 3D printers, particularly those using high temperatures and lasers, is debated. Researchers differ in their assessments of whether additive manufacturing uses more or less energy than traditional manufacturing methods, as it varies depending on the technology and material used. The energy mix of the electrical grid also plays a significant role in determining the sustainability of the manufacturing process.

Exploring the Hazards

When filaments are subjected to heat and extrusion in 3D printing, they release various compounds into the surrounding environment. While some compounds are benign, others pose health and safety risks to individuals engaging with them. These emissions can be categorized into three primary groups: volatile organic compounds (VOCs), fine particles, and ultra-fine particles (UFPs). Certain VOCs and UFPs have the potential to become carcinogenic if they persistently interact with the lungs and skin over prolonged periods.

It's important to note that not all materials release VOCs and particles at the same rate, with equal intensity, or of the same diameter. The overall outgassing is influenced by factors such as the base polymer, the manufacturer, additives, and a range of variables, including nozzle size, temperature, flow rate, and print duration.

However, the emission rate and intensity alone are insufficient to assess the risks associated with exposure. In reality, the highest concentration of VOCs in the air occurs within the first five minutes of the printing process. Subsequently, these VOCs tend to naturally adhere to particulate matter, leading to a significant reduction in emissions.

Among the most commonly used materials, ABS is considered a high-emission material due to its initial emission spike and its continuous release throughout the entire printing phase. Conversely, PLA exhibits higher baseline toxicity during the initial emission phase when compared to ABS. Nevertheless, as the printing process advances, ABS regains prominence and surpasses PLA in terms of overall emissions.

3D Printing Raises Concerns Over Particle Emissions As 3D printing becomes more common in households, questions arise about the safety of the fine and ultrafine particles released during the process. Researchers have delved into the chemical makeup of these particles, compared them to the original filaments, and examined their potential for toxicity. Findings indicate that particles emitted from polylactic acid (PLA) mainly consist of the filament material and resemble PLA monomers, whereas acrylonitrile butadiene styrene (ABS), printed at higher temperatures, releases a higher quantity of particles with a composition that differs from the filament, possibly due to trace additives. Both PLA and ABS emissions raised concerns in both in vitro cellular assays and in vivo mouse exposure, with PLA particles causing more pronounced responses at similar mass levels. Assessments using a common method for evaluating ambient air quality showed that particle oxidative potential of various filament materials is similar, albeit slightly lower than ambient particulate matter (PM2.5). However, ABS filament emissions are particularly worrisome due to their significantly higher levels. These findings suggest that 3D printer particle emissions should not be underestimated, and measures to reduce exposure are prudent. — Particles from polylactic acid (PLA) mostly resemble the filament material, while acrylonitrile butadiene styrene (ABS) emissions differ, possibly due to additives.

So, the question arises: how can we safeguard ourselves amid all this?

When it comes to addressing emissions and personal safety in the realm of 3D printing, there currently needs to be more comprehensive information available. However, you can take specific measures to minimize these emissions.

There is a list of dropdown menus that will help provide additional information on the topic.

To mitigate them, consider the following steps:

1. Lower the printing temperature. 2. Opt for a smaller nozzle diameter, with a 0.4-mm nozzle producing the most minor particulate matter.

To maintain air quality and minimize the presence of volatile organic compounds (VOCs) and ultra-fine particles (UFPs), you can follow these guidelines:

In conclusion, while 3D printing offers significant sustainability advantages, it has ecological and operational challenges. Navigating these challenges and fostering innovation in sustainable practices is critical to maximizing the benefits of additive manufacturing while minimizing its environmental footprint.

Keywords: Relics, Renaissance, Repair, 3D Printing, Environment, Metal deposition, Aerospace, Military, Education, STEM, Additive Manufacturing, Laser Metal, Ford Motor Company, PLA, ABS, Carcinogenic, VOC, UFP, Ultra-fine Particles, Volatile Organic Compounds, Filamentive, Health Hazards, 3D Printing Overview

Would You Still work with 3D Printing at your Home?