MyLastTrash: 3D printing waste

Sustainable Food Systems


We are launching a poster and video competition to help us spread awareness about proper disposal techniques and the potential impacts of 3D printed and bioplastic waste streams! 

Over the last ten years, 3D printing has risen from an expensive and relatively obscure manufacturing method to a mainstay in the Arts, Science, Technology, Medical and Engineering Fields. The many benefits of 3D printing are utilized by researchers, manufacturers and hobbyists alike: fast prototyping and turnaround time, ease of use, affordability and accessibility. The uses for 3D printing are endless; the manufacturing technique is used to make medical implants and prosthetics more customized and affordable, replacement parts accessible, and the imagination realizable. People have created prosthetics, solar cells, organs, bicycles, furniture, guitars, food and much more.

In most cases, the use of 3D printing, an additive manufacturing process, creates a net reduction of waste; typical manufacturing currently has a scrap (waste) rate saturated at 21% among professionals. Our experience with learners new to 3D printing is much higher, estimated at roughly 60%. The continued increase in utilization of 3D printing has the potential to reduce the scrap rate to roughly 10% in the next 25 years. Furthermore, the waste produced from PLA 3D printers is free from contaminants and is considered biodegradable. Alongside these benefits, local or on-site 3D printing such as can be found at universities, community makerspaces, or even inside homes reduces packaging and fuel consumption from product shipment.

Unfortunately, as the popularity of 3D printers increases and as the printing material becomes more affordable and accessible, there is the potential for a net increase in total waste. Waste from 3D printing is created in two primary ways. Structures, such as supports and rafts, are printed alongside the model to prevent deformation. These are then removed from the print and thrown away. The second way is through failed prototypes and design mistakes. During any development process, project success is a result of optimization and learning from errors - usually in 3D printing the entire model is scrapped in favor of the newer version. Students, technicians, and hobbyists are developing and iterating prototypes much more quickly as a result of this technology. Even in the best case scenario, if we combine the 10% scrap rate with the growing popularity of 3D printing (20.6% per year based on market value) we see that action in this area is needed in order for the University of California to hit the zero waste mark by 2020.

So what exactly is being thrown away? The answer is: Plastic. The two most commonly used plastics in 3D printing are polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). Some may object here, “aren’t those already recyclable? I heard you can even compost PLA-which is why it can replace disposable plasticware.”

While this is technically true there are some important caveats:

  • PLA is derived from biomass (often sugarcane or corn starch) and is biodegradable. However, special conditions are necessary to biodegrade this material effectively; industrial composting can decompose PLA within 3 months. Compare this with 100 - 1000 years it would take in a landfill. Although these facilities exist in California, waste from 3D printing often does not end up in one, due to the lack of education and logistical impediments.
  • ABS is derived from petroleum and does not biodegrade. It is, however, recyclable. Unfortunately, you often find a trash bin next to 3D printers, not recycling bins.


Our goal with this project is to address plastic waste from 3D printing, and identify solutions before it becomes the problem becomes unmanageable. Additionally, our team believes that this approach can help the already unmanageable problem of the PLA wastestream from dining halls into the recycling bin, which is responsible for UCSC's plastics being diverted to landfills.  

Our team has a two-fold plan to increase the rate of 3D material recycling:

1. By reforming and reusing waste plastic material (both PLA and ABS)

As part of our goal to achieve zero net waste, we plan to characterize the feasibility of on-site recycling and reusing plastic waste from local 3D printers and quantify potential impacts. To accomplish this, we will pilot filament extrusion from recycled plastic to create new 3D printing materials with up to an 80% recovery rate. This means that waste plastic will not only be recycled, but the consumption of new plastic will be reduced!

Since plastic quality is always downsized during recycling, part of the investigation will be to optimize the percentage of new plastic material used to maintain usable quality. We will also experiment with other plastics commonly found in waste, such as water bottles. This process will require some research and testing before the recycled filament can be used in actual production.

While ABS and other plastics are generally able to be recycled, this process requires specialized facilities, transportation (sometimes as far as China) and tremendous energy, resulting in an increased carbon footprint. With this proposal, we hope to maximize waste reduction locally while maintaining quality printing capabilities, thus minimize transport associated with sourcing materials and their end of life. All this while ultimately reducing the necessity of purchasing virgin plastic material that will ultimately end up in the waste stream.

2. By educating users both on and off campus in the proper disposal of 3D printing waste

We are launching a competition to help us spread awareness about proper disposal techniques and the potential impacts of 3D printed and bioplastic waste streams! Find out more here!

The second part of our plan is to educate the users of 3D printers and the campus/community as a whole about reduction of waste and appropriate recycling methods. Though the majority of the collected 3D printing waste will be generated locally, we believe it is still important to spread awareness regarding proper disposal techniques for waste from 3D printers and other fabrication processes to other campuses, facilities, and potential users.

Find out more and win prizes:

Take the pledge at MyLastTrash Campaign for Zero Waste