Method of producing an evacuated insulated container

Sheets of gas impermeable plastics material are vacuum-formed to produce semi-rigid trays or shells each having side walls extending to form a peripheral flange. The formed shells define a cavity which is filled with an insulation media such as an open cell rigid foam material or a dry silica powder. In one embodiment, a media filled shell and a gas impermeable plastic cover sheet or partially assembled inner and outer shells separated by the media, are placed within a vacuum chamber, and overlapping edge portions or flanges are sealed by a moveable platen after evacuation of the media. The shells may include inner and outer lip portions on opposite side walls to provide for placing two of the insulated shells together in opposing relation to form an insulated container. In another embodiment, the overlapping flanges of the inner and outer shells are sealed together, and the insulation media between the shells is evacuated through a tube which is then closed and sealed.