A tray (100) or container (478) which may be hermetically sealed having a flange encapsulated by or formed from injection-mold material. The tray (100) has a flange (116) extending outwardly from a sidewall (114) of the tray, and containing irregularities induced by the creation of the tray (100). An encapsulating material surrounds the flange (116) in substantially uniformly thick manner, and along with the flange (116) defines an encapsulated rim (124). The encapsulating material is generally a plastic such as polyolefin, nylon, or polyethylene, but may also be made from other materials. This encapsulating material covers a portion of the flange (116) and extends a set distance from the flange's (116) outer edge.