Patent ID: 6371327
Filing Date: 2002-04-16
Classification: B29C,B29K,B29L,B65D

Abstract:
A compartmented disposable food serving article having a substantially planar bottom portion and a plurality of rib portions configured so as to segment said article into a plurality of food serving compartments, wherein said rib portions are substantially angularly joined to said bottom portion and wherein said food serving article is thermoformed from a softened mica-filled polypropylene sheet utilizing a plug-assisted thermoforming process comprising:(a) positioning said softened mica-filled polypropylene sheet to be formed in proximity to a thermoforming mold having a substantially planar mold surface and a plurality of rib portions projecting axially from said substantially planar mold surface, said rib portions defining a plurality of angular junctions with said substantially planar mold surface; (b) thermoforming said disposable compartmented food service container, wherein a plug-assist member is applied to said softened mica-filled polypropylene sheet to urge said sheet toward conformity with said thermoforming mold, said plug-assist member comprising a plurality of rib relief portions positioned, configured and dimensioned to fit about said rib portions of said mold in a forming operation at a forming clearance distance of about 0.125 inches or less from said mold, said plug being provided with a plurality of substantially vertical wall rib relief portions configured and dimensioned to be substantially vertically aligned with said angular junctions of said rib portions of said mold with said substantially planar mold surface, said vertical wall portions being adjacent a plurality of angular corner portions transitioning between said vertical wall rib relief portions of said plug and a bottom surface of said plug.