Nzambi Matee was "tired of being on the sidelines" as she watched civil servants battle the constant onslaught of plastic waste in Nairobi each day. To help remedy the situation, the engineer discovered a way to turn recycled plastic into a product that is 5 to 7 times stronger than concrete.
Gjenge Makers, Matee's company, transforms plastic into super durable building materials. She also designed the machines that manufacture Gjenge Makers bricks.
Prior to launching the company, Matee worked as a data analyst and oil-industry engineer. Inspired, she quit her job to test various combinations of sand and plastic in a small lab in her mother's backyard.
She was able to develop a prototype for the machine after earning a scholarship to study in the materials lab at the University of Colorado Boulder.
"There is waste they cannot process anymore; they cannot recycle. That is what we get," she said.
Gjenge Makers receives large quantities of high- and low-density plastic polyethylene and polypropylene from local packaging plants for free.
The versatile materials are pressed into different thicknesses by a hydraulic machine. The bricks are sold in a number of colors, averaging $7.70 per square meter.
Thus far, the 29-year-old's company has employed 112 people and produces roughly 1,500 bricks each day. Gjenge Makers has recycled about 20 metric tons of plastic waste since the company's establishment in 2018.
"It is absurd that we still have this problem of providing decent shelter—a basic human need," she said. "Plastic is a material that is misused and misunderstood. The potential is enormous, but its afterlife can be disastrous."