Reducing and Recycling 3D Printer Waste
Most of us recognize that there's a huge problem with how much of our waste goes to landfills, and so try to reduce, reuse and recycle as much as we can with the daily items of our lives. But what about the plastic used for 3D printing? It can seem a bit daunting to figure out how and where to best dispose of failed prints and the plastic byproducts of your prints due to the complex nature of plastic recycling. However, there are a few things to keep in mind in order to reduce the environmental impact of your prints.
Which Types of 3D Printer Filament are Recyclable?
We will focus on a type of plastic used as 3D printer filament known as thermoplastic, which becomes pliable when heated to its melting temperature, and doesn't have a curing step. Although most plastics that are classified as such are technically recyclable, the actuality is that there is a wide variation in the specific types that are actually accepted at different processing plants. Unfortunately, even though PLA and ABS are recyclable, they are classified under the ASTM International Resin Identifier Codes as Type 7, and most curbside municipal recycling programs do not recycle them. PET can be included in some curbside programs, but don't mistake that for PETG, which is chemically similar, but is a contaminant during the recycling of PET. However, there are many independent plastic recycling companies who will accept these various materials, so your best bet is to call these local companies and ask whether they process the type of plastic you are using in your prints. Some may be hesitant to accept from a non-verified source, but many are willing. Be sure to keep the different types of plastic separated with the plastic types clearly marked.
Is PLA Recyclable?
Perhaps the most exciting filament to work with when it comes to recycling is PLA, which is actually biodegradable plastic. Industrial composting facilities create conditions in which PLA is broken down into harmless molecules such as water and carbon dioxide by providing the right conditions for microorganisms which can feed on the plastic. Unfortunately, creating the conditions necessary for the breakdown of PLA is beyond the scope of most home composters, but if you can find an industrial composting facility to take your PLA, please do.
The complication is that most printed PLA waste is not easily biodegradable because of its geometry. Thin sheets of PLA have a lot of surface area for the microorganisms to get to work on, but not so much on a bulky, failed print. Until more industrial composting facilities are equipped to handle such difficulties, don’t mix your PLA waste with the compost stream, as it will just be removed and sent to the landfill anyway. In part 2 of this article, we will cover more ways to reduce and recycle 3D printing waste.