They take plastic from commercial and household use (the split is about 60 percent commercial and 40 percent household) and use a granulator to turn it into small pieces of no more than 5mm. Their website details the process: “Next, the plastic granules are mixed with our activator—it’s this that makes the plastic bind properly into our roads. Our activator is patented and what’s in it is a secret! This blend of plastic granules and the activator—let’s call it the MacRebur mix—then goes to an asphalt producer.”