A polymer sheet for producing a heat-sealed peelable product lid, flow-pack or bag; and a method of producing same. The polymer sheet comprises a lower heat-sealing layer comprising polyolefins and additives, a middle layer comprising a polymer support layer and an upper heat resistant layer comprising a polyamide. The polymer sheet is produced in a single extrusion process, extruding simultaneously at least one polymeric heat-sealing layer and at least one polyamide.
