This invention relates to a process for removing foreign materials from a post-consumer polyethylene terephthalate feed stream which comprises: (1) depolymerizing the polyethylene terephthalate feed stream into a melt having a melt viscosity which is within the range of 0.001 poise to 1000 poise, (2) feeding the melt into a separation device, (3) allowing low density foreign materials to float to the surface of the melt, (4) allowing high density foreign materials to sink to the bottom of the melt, and (5) removing molten polyethylene terephthalate oligomer from an area which is located intermediately between the surface of the melt and the bottom of the melt.