they address the sorting difficulties they have sorting suggestions based on individual plastics' density http://preciousplastic.com/videos/plastics/ http://p

they address the sorting difficulties they have sorting suggestions based on individual plastics' density http://preciousplastic.com/videos/plastics/ http://preciousplastic.com/videos/plastics/ in this first video they demo the density example by first suspending in water, then adding salt to increase the water's density for a more complete seperation