Along every step in our daily lives, we encounter plastic. However, few of us think about what happens to plastic products or packaging after they have served their purpose. With 3D printing machines becoming more common in institutions and people’s homes, the plastic waste they produce is also on the rise. Fortunately, one of the most common 3D printing plastics is biodegradable under the right circumstances. PLA, also known as Polylactic acid, is not petroleum-based and can be broken down in industrial conditions within 1-3 months. This is achieved by heating it up to greater than 140F and providing enough water, along with certain microbes. In the wild, it would take PLA 80 years to decompose. Our team created the Fila-buster, a PLA filament shredder and composting bin. Fila-buster is designed to help speed up the process of PLA degradation, mimicking some of the conditions found in industrial settings, and can also be used to shred plastic for recycling purposes. In addition to the motorized shredder, our product also features heating pads, insulation, a temperature sensor, a safety lid, and a trap door for easy disposal. We used a variety of manufacturing techniques to create our prototype, including 3D printing, laser cutting and water jetting. If further developed, it would allow hobbyists and labs to cheaply dispose of their failed or unused 3D prints in an environmentally friendly way. 

Problem Statement 

To help minimize the negative impact of humans on the environment, the aim of this project is to create a PLA filament shredding and composting bin that enables people and institutions to compost their 3D printing waste in-house and in a timely manner, therefore reducing the amount of plastic that ends up in landfills.  


Our group formed through a shared desire to address some of the pressing environmental issues of our time. We used research and the post-it notes to help us pick more specific problems, as well as a mind map.  

One of the brainstorming techniques we used was a mind map. A mind map works by word association and helped us formulate different specific environmental issues we could focus on. In the middle circle, we had our big theme, the environment. Around our big theme, there were many branches of the environment including water, air safety, and habitat conservation. We came up with many different product ideas to address different environmental issues, including renewable power, waste management, plant care, and CO2 emissions. Some of our early ideas:  


  1. an app that tracks co2 emissions from car exhaust 

  1. solar powered portable phone charger  

  1. PLA shredder and composter 

  1. filament extruder  

  1. smart pot that helps take care of houseplants 

Deciding Alternatives and Ranking

To rank all of our ideas, we set up a weighted decision matrix which had different criteria we agreed upon for our project. We gave each idea a number from one to five and multiplied it by the weight, then added up the scores for each idea. The idea with the highest score ended up being the PLA shredder and composter. 

Final Design And Testing Results

Electrical Systems

To turn our shredders, we ran a 24 volt rated DC motor originally designed for scooters. However, this required us to use a clunky power supply which did not integrate well with the rest of our box. We also used a relay and a speed control system to control when the motor turned on and off. 
Since our design included a shredder meant to crush plastic, we knew that we had to include some kind of safety mechanism to prevent accidents, such as hair getting pulled in or fingers getting crushed.In order to achieve this, we connected the power supply and motor to a relay that only transferred power to the motor if two limit switches were pressed. We installed the switches near the rim of the shredder, and they are activated if the lid is closed. This system does not require an Arduino or other microcontrollers