Mechanical Engineering students at Notre Dame University-Louaize (NDU), Joy-Najem Elkhoury, Joseph Katmarji, and Charbel Eid teamed up to try to find a solution for the main obstacle in the recycling process of shotgun cartridges: the mix of metal and plastic. The project was conducted under the supervision of Dr. Najib Metni, Chairperson at the Department of Mechanical Engineering – Faculty of Engineering (FE), and sponsored by the United Nations Development Programme (UNDP) and the LIRA program.
Every year 25,000,000 shotgun cartridges are sold to hunters, and a large portion of them end up in the Lebanese forests and plains. These cartridges are being left there because plastic needs to be shredded before treatment, and the presence of metal in the cartridge makes it impossible to go through a plastic shredder. Separation of the plastic from the metal is a must for effective recycling. A large quantity of plastic is being thrown to waste because of the little piece of metal attached to it. This is where CARL comes in.
CARL stands for “Cartridge Recycler.” The operation of CARL is based on the principal of materials having different densities. The machine consists of a water basin on top of which a small sized E-scrap shredder is installed, with a conveyor system with a ribbed plastic belt inside. Cartridges are dumped into the shredder where they are broken down into small particles. The particles then fall into the water below. Materials that are denser than water, like metal sink, while less dense materials, such as plastic, float. This differentiation in density ensures an easy separation of metal and plastic. The conveyor transports the sunken metal out of the basin, and an overflow of water transport the plastic particles to another basin. As such more effective recycling of cartridges is achieved.
CARL was built from the ground up with the technical support and expertise in stainless steel machinery of the manufacturer GMM Nakad and Sons based in Roumieh. Even as a prototype, it can produce 12 kilograms of pure Low Density Polyethylene (LDPE) plastic particles every hour: a significant amount of plastic made available for recycling instead of being dumped in forests and the sea.
CARL is now considered a working prototype and will be hosted by an NGO in Fanar which specializes in recycling.