the present invention concerns a process for making polyester containing up to 50 percent by weight transparent recycled waste polyester by a novel equilibrium depolymerization process . the equilibrium depolymerization process of the present invention for making polyester containing transparent waste polyester comprises the steps of providing a stream containing oligomers , feeding transparent polyester waste to an extruder , melting in said extruder said waste polyester , extruding said molten polyester into said stream containing oligomers , completing the esterification creating a prepolymer mixture , and polymerizing said prepolymer mixture thereby producing polyester containing waste transparent polyester suitable for food grade applications . the present invention meets or exceeds the food and drug administration requirements for food contact with polyester and is thus useful in food contact applications , for example beverage containers and polyester film wrap .