A gas exchange manifold includes a pair of plates which may be threadedly connected to one another. Gas supplying passages are formed through the plates to supply a desired gas to the package during fabrication. Also, vacuum supplying passages extend through the same plates and communicate with the package as well. A third plate, which may be sandwiched between other two plates, may contain a plurality of apertures which form part of the gas supplying passages. In this way, the third plate, which may be smaller, may be replaced to provide the desired pattern of apertures for a given configuration of packages being formed.

A method of forming a form stable, preferably product contour tight package in a roller operated packaging machine. A thermoformable web (14) is pre-heated to a suitable forming temperature and the web is thereafter supplied to a mould tray (20). The tray is provided with vacuum passages and/or other arrangements for forced forming to the contour of the tray. A sealing tool (22) surrounds, completely or partly, the periphery of the tray and is used for sealing of the second web to the first one. The heat of the sealing tool is superposed, primarily by heat radiation, onto the cooling, preferably such that a boarder region (26) head/cold is created in the marginal portion of the mould tray.

The invention relates to a method and a device for the sealing of a container (10) by means of a wafer (20). The container comprises one or more joining means (14, 16) which are adapted so that by a joint (12), e.g. a welding joint, they are connected in a leakproof manner, to the wafer in an edge zone (21) of the same. The wafer is held against a contact surface (32) of a retaining means so as to be moved by the same until it rests in its edge zone (21) against anyone of the joining means (14, 16). While the contact with the retaining means is maintained, the wafer is connected by a fixing means (50) in its edge zone in a leakproof manner to anyone of the joining means through the fixing means supplying energy to the edge zone so that a joint (12) is formed. The invention makes it possible to fix in a leakproof manner a previously cut wafer to the opening part of a container. The sealing can be done even on containers with hot contents, since in certain embodiments the retaining means is cooled with the help of cooling ducts (33). The retaining means cools the wafer and prevents it from being deformed owing to the rise in temperature which the proximity to hot contents otherwise would bring about.

An improved sealing gasket for a vacuum-sealing station of a vacuum packaging machine which is made such that the outer perimetric portion thereof is made of a greater hardness than the rest of the sealing gasket, whereby the sealing heat-elements of a reciprocal heating element only substantially contacts against the softer material of the sealing gasket, allowing this softer material to conform to the uneven or non-level condition of the heating element. In the preferred embodiment, the outer-most perimeter of the sealing gasket is made of a greater hardness in the approximate durometer-hardness range of between 60-85 Shore A, while the remainder of sealing gasket is made of less hardness in the approximate durometer-hardness range of between 30-50 Shore A.

An appliance for evacuating a flexible container, the appliance including a base housing and a vacuum source disposed within the base housing. A drip retainer is removeably disposed in the base and is in communication with the vacuum source. The drip retainer includes a chamber for holding material. The drip retainer further including a nozzle projecting therefrom, the nozzle is engagable with an opening of the flexible container. A cover is rotatably connected to the base and movable to a closed position to cover the nozzle.