There may be a path to solving the dilemma of unwanted 3D prints.
Every 3D printer operator knows quite well that there will be an accumulation of stray 3D prints. These will be abandoned prototypes, failed prints, scraps from support structures and just items no longer required.
Some operators toss them out, while others collect them with vague notions of “dealing with them later”. Some believe these 3D prints can be recycled. After all, didn’t we pay good money for the materials before 3D printing? Isn’t there still value there?
The truth is the recycling of 3D prints is a hit-and-miss business. To achieve predictable, reliable and quality 3D prints you must supply consistent and known input material. The consistency is required to ensure the speeds and feeds of the print job will be effective. The ability to know the exact nature of the input material allows the operator to properly select the correct print profile.
However, your pile of waste 3D prints is usually none of the kind. It will most typically be composed of a wide variety of materials from different sources, having different colors and additives. There is virtually no effective way to recycle this material.
In fact, almost all 3D print recycling initiatives start from a known source of material: either a civic utility that is collecting a specific type of plastic waste, or a program in which specific materials are collected by participants. For example, “we’ll pay you to collect 2L Pepsi bottles — only!”
Even worse, PLA, the most commonly used desktop 3D printing material, has been shown to be impractical to recycle. For this reason, I’ve often thought that most desktop 3D printer operators should make a switch to PETG, as it’s an easier material to deal with.
To go along with the PETG thinking, there’s now another possible reason for using this increasingly popular material: recycling.
Researchers have developed an approach that can transform polyethylene material (i.e. PET or PETG) into usable jet fuel.
Apparently the process involves using the rare metal ruthenium and hexane to decompose polyethylene into ingredients that can be then made into not only jet fuel, but lubricants.
The new process is 90% efficient, meaning 90% of the input polyethylene is made into fuel.
Transforming polyethylene into fuel isn’t a new process, as the pyrolysis process can do so. However, pyrolysis requires very high heat, up to 220C, to do so. The new process requires far less heat.
This is important, because the heat used in pyrolysis frequently is obtained from fossil fuel sources. If that energy can be minimized with the new process, then the transformation can be more eco-friendly.
This is, however, only a demonstration of a new process and by no means is a commercially accessible function. Because the technology has been proven, it is now up to entrepreneurs to leverage it to create systems that can collect PET waste, including 3D prints, and make some practical use of the material.