Apparatus with Facing Bell Members for Modified-Atmosphere Packaging of Products Contained in Trays

摘要

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). The third circuit (17) is connected via associated valve means (118) to means (22) for gradual pressurisation, using also atmospheric air, in order to balance the internal pressurisation of the tray with the service gases.

主权项

1. Apparatus with facing bell members for modified-atmosphere packaging of products contained in trays, of the type: which comprises a top bell member which is open downwards and contains the sealing means and preferably also the means for cutting the barrier film closing the trays and a bottom bell member which is open upwards, with a chamber and with at least one seat for receiving at least one tray which may be inserted into and extracted from this seat by special means; which comprises means for positioning a taut section of film between the said two bell members and above the trays; which also comprises means for moving the said bell members towards each other so as to close between them the edge of the tray and on top of the latter the said film; and which comprises means for performing in synchronism extraction of the air from the tray and introduction, into the latter, of service gases for conserving the product contained inside the tray, before the subsequent step of tightly closing and welding the film on the edge of the said tray and subsequent perimetral cutting of the portion of film welded to the said tray; of the type which comprises means for ensuring that, during the closing step, the said bell members form inside them a main chamber which is defined at the top by the film covering the tray, at the bottom by the said tray with the product and on the sides by any suitable mechanical interface structure which surrounds and connects the perimeter of the said film to the perimeter of the top edge of the tray and this interface structure being provided with holes and/or eyelets which are suitably distributed and positioned on the outside of the tray perimeter and communicate with the said main chamber, characterized in that, when the two bell members are closed, two volumes which do not directly communicate which each other are formed inside said bell members, i.e. a first volume formed by the said main chamber with the tray and with the covering film and a second volume formed by the internal intercommunicating chambers of the said two bell members.