Image courtesy of Pixabay.
By Dnyaneshwari Haware ’23
Staff Writer
Tired of waiting for her local government to find a solution for the plastic waste produced by households and factories, Nzambi Matee, a Kenyan materials engineer, invented a process and designed a machine that converts plastic waste into bricks. These bricks are denser and around five to seven times stronger than concrete. Her work has been seen as an important capital resource for Kenya’s economy, as the machine simultaneously solves the issues of plastic waste disposal and a lack of durable housing.
“Plastic is a material that is misused and misunderstood. The potential is enormous, but its afterlife can be disastrous,” Matee said in an article for designboom.
Matee founded her own factory, Gjenge Makers Ltd., which produces 1,500 bricks every day in Nairobi. The bricks are made out of multiple types of plastic, including high-density polyethylene used in shampoo bottles, low-density polyethylene used in plastic wrap and polypropylene used for buckets.
Before founding Gjenge Makers, Matee worked as a materials engineer in Kenya’s oil industry. Matee’s frustration with the accumulation of plastic waste in her hometown of Nairobi prompted her to find a sustainable solution that would solve multiple problems at once.
While the process utilizes different types of waste, there are some limitations as to what kind of plastic can be used. For example, Matee does not work with polyethylene terephthalate, a polymer commonly used to make plastic bottles, because these substances do not bind well together. To make the bricks, the plastic waste is mixed with sand, heated and then compressed. They come in a variety of colors and densities. They are sold at approximately 850 Kenyan shillings ($7.70) per square meter, making them both affordable and durable.
In the designbloom article, Matee further explained that her company works with plastic that cannot be recycled or processed any more. Packaging factories provide the plastic waste for free, while she pays other recyclers for their plastic.
So far, Gjenge Makers Ltd. has recycled 20 tonnes (around 22 tons) of plastic waste since 2017. Matee’s factory is estimated to break even by the end of this year, and she plans to accomplish this by tripling the number of bricks produced each day. The startup has also provided 112 jobs to local garbage collectors, women and youth groups in Kenya.