Abstract: Methods and apparatus for introducing a modified atmosphere into a package and sealing that package with a film are disclosed. Cooperating upper and lower bell members having internal volumes in fluid communication with one another via a duct configured to cause sequential pressure differentials between the volumes permit the sealing film to be controllably retracted from and applied to outflow holes so as to allow evacuation of ambient air using a single constant vacuum source, rather than requiring precision timing controls and/or multiple vacuum sources. Another dedicate circuit introduces the modified atmosphere into the package, and a sealing unit such as a heat welder subsequently seals the film against the package.

Abstract: Apparatus with facing bell members for modified-atmosphere packaging of products contained in trays, comprising at least three circuits: a first circuit and a second circuit (24, 25) which are connected to the main chamber (P) enclosing the internal volume of the trays and open out in different positions (23, 23?) of this volume and a third circuit (17) connected to the internal chambers (2, 9) of the bell members (1, 8) and these circuits are intercepted by respective valve means (28, 128, 18, 118) so as to be initially all connected to the vacuum means (21, 121) and then the said first circuit (24) is closed, while the said second circuit (25) is connected to the means (26) for introducing the service gases which, entering into the tray, force the remaining air out so as to occupy a small buffer formed by the said second closed circuit (24, 28).

Abstract: A device for spreading the tray sealing film in so-called tray sealers, in order to avoid the formation of folds in said film which, with the trays, is inserted in a sealing and cutting station, between a pair of opposing bells provided with a relative reciprocal approaching and distancing movement, where downstream of said station means are provided to subject the off-cut of film which exits to a transversal stretching action which ensures correct spreading of said film between said bells, characterized by comprising means for braking the film upstream of said station and comprising pincer means with a jaw mounted on the side of the upper bell from which the film exits, turned downwards and vertically opposing a corresponding jaw mounted on the lower bell, all being envisaged to ensure that in the reciprocal approach and closure step of the two bells, before the film is gripped and blocked between them, longitudinal and lateral portions of the film which are close to the bells are pincered between said oppos

Abstract: When the opposing housings (1, 8) of the apparatus are closed, they form between them a small main chamber (P) delimited above by the film (H) for covering the tray and below by the tray (V) itself containing the product (M), and laterally by any suitable mechanical interface structure which surrounds the perimeter of said film and connects it to the perimeter of the upper edge (B) of the tray, this interface structure having holes (22) which are suitably distributed, are located outside the perimeter of the tray, and communicate with said main chamber (P). One or more of these holes (22) open(s) on at least one side of the tray and is/are connected to a first circuit (23, 24), while another one or more of said holes (22?) open(s) on at least one opposing side of the tray and is/are connected to a second circuit (17) which in turn is connected to the inner chambers of the two housings (1, 8).

Abstract: The external conveyor supplying the trays coming from the filling machine is connected to a conveyor formed of parallel straps or belts, which has a greater length than the length of the group of trays of larger dimensions to be grouped together and which is provided in the end part with components inserted between the belts, a comb lifter of a length correlated with the length of said tray group to be formed, connected to lifting and lowering means with suitable acceleration and deceleration ramps. Upstream of the lifter, sensors are provided which detect the position in space of the trays arriving from the external conveyor in succession. A processing and control unit is provided to process the information arriving from said sensors.

Abstract: A machine with a packaging station, at which trays having products are sealed. Opposed parallel sets of belts move in synchronism with each other transversely to the direction of movement of the trays along the packaging station. Each set of belts has an upper belt and a lower belt adjacent to each other and moving in the same direction at the same speed. One end of the adjacent runs receives a sheet of film. A plurality of jaws are located on each of the opposed sets of belts, each set of jaws receiving adjacent runs and an edge of the film. The opposed sets of belts are moveable relatively towards and away from each other, such that the jaws can hold films of different widths and such that the film held therebetween can be stretched and relaxed. A clamp is connected to each set of jaws. The clamp is spring biased to the separate the top and bottom thereof. A power element exerts a selective force onto the bottom of the clamp to close the adjacent runs onto the film.

Abstract: A machine with a series of three operating stations, of which the first station arranges the full trays in a predetermined pattern while the second station closes the full trays with a film and in which the third station discharges the full trays. The stations are equidistant from each other. A transfer structure has combs that have a length such as to occupy simultaneously two consecutive such stations and that are provided with the teeth that can grasp the trays, lift the groups of trays and then move longitudinally to transfer the groups of trays from one station to the next, then lower the tray to deposit the groups of trays in the new stations.

Abstract: Between the two housings each having a recess and below and parallel to the film, there is provided a frame having openings greater in plain view than the underlying trays to be packaged, supported such that, during the closure of the housings the frame interacts with seal and contributes to the formation of a main chamber delimited by the upper edge of the tray and by the film above this edge. Air is removed from these recesses to form the desired level of vacuum therein, while, in the main chamber is isolated from the recesses of the two housings, so that the process gases can be injected directly into the main chamber, while a corresponding quantity of atmospheric air is directed into the recesses to balance the pressures on the opposite faces of the film When the process gases have been fed in, the film is welded to the edge of the tray and is cut outside this edge.

Abstract: When the opposing housings (1, 8) of the apparatus are closed, they form between them a small main chamber (P) delimited above by the film (H) for covering the tray and below by the tray (V) itself containing the product (M), and laterally by any suitable mechanical interface structure which surrounds the perimeter of said film and connects it to the perimeter of the upper edge (B) of the tray, this interface structure having holes (22) which are suitably distributed, are located outside the perimeter of the tray, and communicate with said main chamber (P). One or more of these holes (22) open(s) on at least one side of the tray and is/are connected to a first circuit (23, 24), while another one or more of said holes (22?) open(s) on at least one opposing side of the tray and is/are connected to a second circuit (17) which in turn is connected to the inner chambers of the two housings (1, 8).