The invention relates to a method, whereby a cleaning and disinfecting circuit is established for the vacuum channels of an upper sealing tool (1) and a lower sealing tool (2). In the present case, the vacuum pump (3) is switched off and the connecting line to the sealing station is sealed or disconnected from the flanges at the point (10). The vacuum channels of the upper sealing station (1) are connected to the vacuum channels of the lower sealing tool (2) by means of an adapter (13) in a fluid-tight manner. The fluid circuit is closed by a pump (14), a fluid container (15) and the associated pipes, which are connected to the flanges (11), (12). Said pump (14) pumps a cleaning and disinfecting fluid, in the present case active chlorine, into the vacuum channels of the upper sealing station (1).

A bagging and packaging machine for forming a bag from a strip of bag material and introducing an article into the bag includes a gas supply unit for supplying an inert gas into the bag to substitute for air contained in the bag and a gas supply control means for controlling supply of the inert gas by the gas supply means into the bag. The bagging and packaging machine is designed to allow the inert gas to be supplied under high pressure at a flow rate sufficient to increase the gas replacement rate in the bag when the machine is started, to be supplied under low pressure at a flow rate lower than the high pressure flow rate during a bagging and packaging operation subsequent to the start of the machine. Should the machine is temporarily brought to a halt, the length of time T passing from the timing at which the machine is temporarily brought to a halt is counted by a timer without the supply of the inert gas being interrupted, so that the supply of the inert gas can be interrupted at a timing the counted length of time exceeds a low pressure gas supply time T2. In this way, without the bag being bitten during bagging and/or the bagging and packaging speed being lowered, not only can the inert gas be sufficiently filled in the bag to achieve a high gas replacement rate, but the amount of the inert gas supplied can also be suppressed.

An air spring assembly has a pair of spaced end plates and a flexible sleeve extending therebetween forming an internal fluid chamber. One of the end plates is a bead plate which is crimped to an open end of the sleeve. An insert having an internally threaded hole is mounted in a central hole formed in the bead plate. An externally threaded coupler having a hollow bore is mounted in a central opening formed in an end member of an auxiliary reservoir and is threadably engaged with the internally threaded hole to mount the auxiliary reservoir in an abutting relationship on the air spring bead plate to provide a variable rate air spring. A fluid path is provided through the threaded connection for the flow of fluid between the air spring and auxiliary reservoir.

The machine comprises: a reel (3) with means (4, 104) for controlled unwinding therefrom of film (30) for closing the trays; first means (5) which are situated underneath the said reel and around which the film is deflected so as to pass from a descending path to a horizontal path; counter-die means (12) for supporting at least one tray (V) horizontally, along the upper edge (Z), with a predefined orientation and for displacing it horizontally underneath the said horizontal section of film, with entry via the said first means (5) for deviating the said film and with feeding in synchronism with the film which gradually closes the tray at the top; means (5) situated downstream of the first film deviating means (31), for sealingly welding the film onto the upper edge of the tray; means (27) situated upstream of the said first deviating means (5) for blowing an appropriate amount of the modified atmosphere at appropriate pressure values into the open part of the tray which advances underneath the film until the tray itself has been completely sealingly closed by the film; means (48) for separating from the film the portion thereof welded to the upper edge of each tray containing the product under a modified atmosphere; means (7, 107) for taking up the waste film produced by the said separation means (48), which operate in conjunction with the said means for unwinding the film from the said reel, so as to ensure that at least the section of film along the said horizontal path advances always stretched both longitudinally and transversely; means (29, 427, 8) which, at the start of the cycle, feed and position correctly in the counter-die means (12) the trays (V) to be closed and means (15) which, at the end of the said cycle, raise from the said counter-die means and prepare for unloading, the closed trays (V1) having inside the product under a modified atmosphere; means (58) for conveying away the closed trays (V1); means (10) for horizontally moving the said counter-die means, which at the end of the cycle bring these means (12) back into the starting position, for repetition of a new working cycle.

A method for packaging a product arranged in a tray is provided. An upper film located in a distance above the product is clamped along an edge surrounding the tray and is deformed in a direction extending away from the product. Subsequently, evacuating of the space surrounding the product is performed, then a raising of the tray towards the upper film and finally a sealing of the film and of the edge of the tray. In this way, the seam of the upper film and the edge of the tray is attained to be free from creases such that a long-living and good looking package is produced. Additionally, a packaging machine for performing the method is provided.