Patent ID: 8470224

Claim:
A method of manufacturing a sheet for food containers, which comprises: adding a chain extender having two or more epoxy groups to moist flakes of recovered PET; charging the flakes of recovered PET containing the chain extender into an extruder having three zones and two or more vent holes, said three zones comprising: a first zone wherein the charged recovered PET is heated to melt and kneaded together with the chain extender, a second zone wherein depolymerization occurs partly in addition to polymerization reaction by the chain extender, and a third zone wherein polymerization reaction occurs by the chain extender, and said two or more vent holes comprising a first vent hole located between the first zone and the second zone, and a second vent hole located between the second zone and the third zone; melting and kneading the flakes of recovered PET with sucking to degas through the vent holes; extruding the recovered PET from the extruder into the sheet, and applying the sheet to a food container.