3D printers have been available as commercial equipment for quite a few years now, but some people do focus on buying the less polluting or the most eco-friendly materials, this to help protect the environment. So for this specific purpose, it is quite useful to know which kind of printers and materials are the “greener choice”.
Some important aspects to consider while choosing a “green” 3D printer and material are the following:
- The manufacturing process involved in the making of the material to be printed.
- The origin of the raw material used to produce the material to be printed.
- Printer material capabilities (temperature, available extruder or multi-material support, nozzle diameter, feeding speed, heated-bed option)
First of all is important to mention that a 3D printing material that is fully eco-friendly with a low carbon footprint value and that will result as functional as other materials, isn’t easy and neither a cheap solution to find, with that in mind, there are several materials that will suit the task of a less polluting material than others.
At this point on, we will focus on fused deposition modeling (FDM) 3D printers, this type of printers use thermoplastic filament or pellets and melt them to later force the molten material through a nozzle, which deposits the material on the working bed to the desired shape.
There are several types, brands and colors of plastic filaments, the properties vary for a same material from brand to brand, or even from color to color (of the same brand and type of plastic), this is a factor to take into count, as the set-up values for the 3D printer may need to be modified in order to obtain an appropriate print.
Two of the most common plastic filaments used for entry and advanced users are PLA (polylactic acid) and ABS (Acrylonitrile butadiene styrene), ABS is a petroleum derivate product and PLA is biodegradable and bioactive thermoplastic derived from resources such as corn, roots, sugarcane and other renewable resources. From these two materials we know the greener choice is PLA, first from the raw materials it is made and second because it takes less energy to be produced.
ABS has some advantages over PLA; one of them is the ability to endure higher temperatures without deforming. Another advantage is that ABS has higher resistance to distortion under the stress of an applied force. ABS has a green side to, it can be recycled, meaning you can extend the life cycle of this material, however there is a main disadvantage, fumes emitted when the plastic material is heated to high temperatures hold toxic byproducts which are proven to be carcinogenic.
PVA (Poly-vinyl alcohol) is synthetic polymer that can be soluble on water, this type of plastic is highly biodegradable and is often used as a support material in general purpose 3D printing, in particular where complex structures need to be made and need a support material in order to accomplish such geometry (e.g.: a hanging bridge, where support material will be laid in order to support the hanging part of the bridge, to later be removed by leaving in water).
One important thing to consider when using PVA is the need of multi-material support on your 3D printer, this in order to use a plastic such as PLA as primary material and PVA as the support to be later removed.
There are some commercially available recycled filaments from ABS, PET, HIPS and PLA such as ReFilament, made from recycled plastic bottles and old car dashboards, made by the Dutch startup Refil.
Plant-based 3D filament has also been developed, we’ve talked about PLA and how it can be derived from corn and other plants, but there are other plastic filaments made from soy or weed, such as FilaSoy and SeaWeed correspondingly.
Wood filament has also been manufactured and varies in the percentage of wood it consists, this wood filament is made of natural wood fibers mixed with plastic, commonly PLA, the final 3D printed pieces can be treated as wood, as they can be sanded, polished and even dyed; The most common brands and filaments include LayWood (40% wood), WoodFill (70% and 30% available) and BambooFill (50% bamboo fibers).
It is recommended to use a 0.5mm nozzle head for Filaments made out of wood, using a 0.4mm or even lower diameter may result in nozzle clogging. LayWood for example also requires a hot surface (heat-bed calibrated at 60°) to lie out the print to avoid warping.
There are other alternatives to make your own recycled filament, one of the most known is Filabot, a machine that can turn an old plastic milk bottle into 2.5 meters of extruded filament and the process is the following:
- First you need to grind plastic (discarded 3D prints, old 3D prints, plastic bottles, etc.) from the same material type and transform it into granules (or skip this step and buy plastic pellets from a recycled source).
- The machine heats and extrudes these granules/pellets to the desired filament width (1.75 or 2.75 mm)
- The filament is then wrapped around a spool so that it can be reused again by a 3D printer.