Providing effective filtration for 3D Print Farms
The proliferation of 3D print technology and its growing cost-effectiveness is spawning investment in print farms focused on leveraging the value of additive manufacturing at scale.
This trend towards creating facilities with multiple 3D print systems aims to exploit the speed, quality, productivity and customisation benefits of innovations in both technology and materials science. However, with this scaling up comes a need to manage chamber and airborne emissions that if not adequately controlled have the potential to be harmful to human health and to impact on product quality.
And it’s not always recognised names in manufacturing that invest in print farms. Often, hobbyists with just one 3D printer find a niche market and take advantage of cost-effective but high-quality technology to build their capability. While a print farm can technically refer to any establishment which has more than one printer, it is more often applied to sites with tens and maybe hundreds of units in operation.
Nigel Bedford, Technical Development Manager at Donaldson BOFA, explains why print farms have grown in popularity. 
“Just like traditional manufacturing processes, volume drives benefit in terms of cost and process standardisation. The big cost drivers in additive manufacturing are the materials and the upfront capital required for machines, so leveraging value from volume certainly brings significant benefits.
“The challenge for any print farm can be keeping all the printers busy. Today many relatively low-volume, medium-value plastic products are produced in this way. These include, for example, dental moulds and custom orthodontics where products are bespoke but required quickly.
“While volume is key, what additive manufacturing also provides is the ability to produce one-off items – a good example here is a leading men’s shaving brand offering customised razor handles matched to an individual’s handgrip. This would be impossible without 3D printer technology.”
Filtration in Print Farms
So what are the implications for filtering process emissions?
“Donaldson BOFA has good experience of developing extractions systems capable of supporting multiple devices through enhanced airflow technology and high-capacity multi-stage filtration architecture, including carbon media,” says Nigel.
“Producers need to be aware that a concentration of 3D printers can create a risk to air quality if emissions are not appropriately extracted, filtered and clean air returned to the workplace. Our research on airborne particles emitted from melting plastics showed that there are airborne contaminants that can create health concerns, so where print farms are growing their capabilities, they need to invest in effective extraction technology.”
Print Farm Challenges and Donaldson BOFA’s Solutions
The 3D printing processes favoured by print farms tend to be Fused Deposition Modelling (plastics) and Resin machines, which can be scaled-up cost effectively and quickly.
In a print farm environment, the fume extraction set-up will depend upon the process, the material being worked and the volume and chemical composition of the emissions.
Emissions may take the form of nanoparticles which may be odourless but present nonetheless and VOCs, typically characterised by an odour. Users should undertake their own due diligence and risk assessment as to the appropriate limitation of exposure. Donaldson BOFA can support bespoke enclosures and extraction solutions for print farms allowing efficient extraction to help mitigate risk.
For metal powder processes, Donaldson BOFA’s AM 400 is proving to be a popular choice due to its ability to support low oxygen concentrations to avoid any oxidization or flaws in the final printed item. The AM 400 has been designed to maintain the argon-rich environment required with low oxygen ingress. It also has a mobile filter assembly for post-process treatment and an embedded blower system which are ideal for metal processing.
“For high-end metal printers, a collective filtration system is not practical due to the high volumes of condensate produced, especially when working reactive materials such as aluminium and titanium,” says Nigel. “However, the cost of investing in these AM machines and the high value of the parts produced makes extraction technology an essential contributor not just to workplace safety but to productivity by keeping print heads free from dust.”
For high-volume plastic feed print farms, Donaldson BOFA’s filtration technology is extremely effective at removing sub-micron particles, while for resin printers, the addition of a carbon layer is of great benefit to atmosphere management and protecting print quality.
