in today &# 39 ; s environment , it is becoming increasingly more important to recycle plastics including polyethylene terephthalate . technology available today allows for polyethylene terephthalate to be recycled into a wide variety of useful products . for instance , carbonated beverage bottles which are comprised of polyethylene terephthalate can be recycled into new polyethylene terephthalate beverage bottles . however , a relatively pure polyethylene terephthalate post consumer feed stream is required in many such recycling programs . unfortunately , such feed streams are often contaminated with foreign material . this invention relates to a process for removing foreign materials from a post - consumer polyethylene terephthalate feed stream which comprises : 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 , feeding the melt into a separation device , allowing low density foreign materials to float to the surface of the melt , allowing high density foreign materials to sink to the bottom of the melt , and removing molten polyethylene terephthalate oligomer from an area which is located intermediately between the surface of the melt and the bottom of the melt .