Wie weet waar je gecertificeerd composteerbaar PLA filament voor 3D printers kunt kopen of kent een fabrikant die gecertificeerd wil worden? Laat het ons weten. MountGreen wordt graag klant!
Benieuwd waarom we dat zoeken? Lees dan verder (in English).
The potential of PLA
Poly lactic acid (PLA) is a wonderful bioplastic. Not only is it made from biomass instead of fossil resources, it is also biodegradable. Today PLA is mostly made from corn starch and sugar cane. But it can also be made from agricultural and forestry residues: feedstock that provide a huge potential for the production of PLA, as mentioned in this study from Wageningen University.
Biodegradable is not the same as compostable
Because PLA is bio-based AND biodegradable, we chose it for the production of our plant pots. To many, a “biodegradable pot” sounds as a pot that will disappear quickly when tossed in the garden. But that’s not the case! Luckily. We wouldn’t be able to grow plants in pots that disintegrate when put in contact with water and soil. Biodegradable just means that a material can be eaten by microorganisms (bacteria and fungi). It will be hard though fore these microscopic animals to quickly break down a solid block of PLA, the surface area is just too small. The real question is how quickly a PLA part will broken down into small fragments under composting conditions like in a compost heap or composting facility.
Not size, but thickness matters
One of the larger PLA suppliers is NatureWorks. Their Ingeo resin is the main component of many 3D-printing filaments. 3D parts printed with the specific granulate (2003D) used in the filament we make our pots from decompose under industrial composting conditions if less than 3.2 mm thick, as defined in the European EN 13432 standard*. Our pots are only 0.8 mm thick, so that suggests they are good for organic waste collection. Unfortunately, there is one more hurdle: pigments!
Are pigments eco-friendly?
PLA is transparent. Transparent filament is not very suitable for making plant pots. Roots usually don’t like sunlight. To make coloured filament, pigments are added to the PLA granulate (and sometimes binders too). So in order for our pots to really be compostable (and other 3D printed parts from coloured PLA less than 3.2 mm thick!), we have to make sure the pigments are bio-friendly too. Now here we hit a roadblock: we are entering the kitchen of PLA filament manufacturers that are keen to protect their secret recipe.
3D filament manufacturers: can you please certify your PLA filaments?
The only way to be 100% sure that our coloured PLA plant pots (and other 3D printed parts less than 3.2 mm thick) are compostable, is if manufacturers obtain certificates for compliance with the EN 13432 standard. There are two options in Europe: the seedling logo and the OK compost logo. I’m calling all filament manufactures to apply for one of these logo’s, so end-users know whether or not their 3D-printed PLA parts are compostable or not.
In the bin, for the time being
For now, our plant pots can best be thrown in "the bin”. An alternative which is also good according to Milieucentraal. In the Netherlands, household waste is incinerated with energy recovery, thereby extracting bioenergy from our plant pots.
*The key requirements of the EN 13432 standard are:
- At least 90% of the product should pass through a 2x2 mm mesh after 12 weeks
- At least 90% of the materials should break down by biological action within 6 months
- Limits for volatile matter, heavy metals and fluorine content
- The quality of the final compost should not decline as a result of the (degraded) components and pass an ecotoxicity test