Method of making flat foam sheet comprising recycled pet and the product resulting therefrom

Abstract

A method of making multilayer foam sheet from recycled polyester sources, which may be used for packaging applications. The method comprises a co-extrusion system comprising at least two single screw extruders. A low I.V. polyester feedstock comprising up to 100% of the polyester flakes from recycled sources with an intrinsic viscosity (I.V.) of lower than 0.8 dL/g as measured by ASTM D4603-18 is directly being fed into the extruders. Supercritical physical blowing agent is introduced into the melted polyester feedstock in at least one of the extruders wherein the processing temperature is in the range of 15% lower than the melting temperature and 15% higher than the melting temperature. Then, coextruding the feedstock from the extruders of the co-extrusion system through a flat sheet die to make a multilayer foam sheet, wherein at least one layer is a foam layer comprising low I.V. polyester.

Dependencies are inferred from the claim text.