Abstract: A container (40) has a body (41) having an open end (42) surrounded by an outwardly and downwardly extending flange (43). A closure (44) is adapted to be sealed to the container body (41). The closure (44) has a flange clamping portion (48) such that when the closure (44) is mounted to the body (41), the flange clamping portion (48) forms a seal with at least the outer surface of the flange (43) by exerting pressure inwardly against the flange (43). The flange clamping portion (48) can also be adapted to form a seal with the open end (42) of the body (41) and the inner surface of the container body (41) proximate its open end (42). A thread ring (10) adapted to be mounted to the open end of a container is also described. The thread ring has a retaining means comprising a continuous hook (13) that is adapted to sealingly engage the open end of the container and so provide a means for closures to be readily and sealingly attached to containers.

Abstract: A plastics container (10) for hermetically sealed unrefrigerated storage of perishable food that is capable of retaining the hermetic seal during steam retort cooking and sterilizing at temperatures up to 130.degree. C. The container has a body (12) and cover (16) of a lightweight, disposable nature made from thermoformable plastics barrier sheet capable of prolonged resistance to transmission of oxygen, other gases and water vapor. The container and lid have flange portions (14, 18) that are retained in contact by an injection moulded thermoplastics reinforcing clamp ring in two pieces, a plug half (24) and a socket half (26) that twist-to-lock together in screw thread manner. The clamp ring parts are preferably of polypropylene and moulded with structural cross-sectional thicknesses (t1, t2FIGS. 4, 5) at least twice the thickness of that of the body sheet.