Abstract: 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 t

Abstract: 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 t

Abstract: Extensible multilayer film comprising two external layers made of thermoplastic polyolefinic resins, two optional intermediate adhesive layers and one central layer; the said external layers being realized with ethylene/?-olefins copolymers resins, the said optional intermediate layers being realized with adhesive resins preferably containing linear low density polyethylene modified with polar groups, ethylene vinylacetate terpolymers, or maleic anhydride modified ethylene acrylate, the said central layer being realized with resins which impart to the film, sinergetically with the other components of the same film, the following features: glass transition temperature in a range between 20 and 70° C.; longitudinal strain greater than 200%, at a temperature comprised between 25 and 45° C., applying reduced load, less than 0.5 N/mm; necking in the range of the 40-60%; longitudinal thermo-shrinkage in the range of 40-60%; residual elastic memory, giving rise to a longitudinal force less than 0.

Abstract: An apparatus for sealing longitudinal overlapping edges of tubular thermoplastic film. The apparatus comprises a fixed block (31) for guiding and holding the overlapping edges and a sealing head (6) spaced from the fixed block for directing jets of hot air onto the overlapping edges of the film guided on the fixed block. The sealing head (6) is movably mounted such that the sealing head is positioned a short distance from the film as the film is advancing and the sealing head is withdrawn from the film when the film is stop.

Abstract: A stretch film presenting controlled permeability to gases, manufactured by process of balloon co-extrusion and consisting of outer layers (S2) of stretchable polmeric material and by one or two inner barrier layers (S3) of a EVOH based polymeric matrix, which is made stretchable by the addition of a suitable plasticizer in such a percentage as to conciliate the stretchablity with the desired barrier effect, said layers of different material being reciprocally secured by means of layers (S4) of adhesive material. The polymeric matrix which forms the barrier material and the plasticizer are intimately mixed inside a double-screw corotating extruder, immediately before the phase of co-extrusion, through a premelting of the polymeric matrix and the subsequent injection of the plasticizer in liquid phase.

Abstract: Means are provided to ensure that during the stage of formation through the tube- forming and longitudinal welding means (1, 18) the wrapping is subjected to longitudinal stretching which causes it to adhere intimately in a direction transverse to the product and this condition is ensured by means which bring about a particular difference in velocity between the jaw (19, 119) which supports the tubular wrapping and causes it to advance and the means (15, 115, 17) which feed the film to the tube-forming means (1) which also remain suitably active during the subsequent stage in which the tubular wrapping is seized posteriorly by the appropriate posterior closing jaw (119, 19), all in such a way that the wrapping film runs over the said tube-forming means in an almost continuous movement to prevent localised appearance defects in the packaging and to assist operation of the longitudinal welding means (18) which are then able to operate substantially continuously.

Abstract: The electrical resistance is housed in a composite body made of a material which is a good heat conductor, externally insulated so as not to leak heat into the external environment and machined in any way so that it comprises internally at least two separate and offset channels (4, 5) having identical dimensional characteristics and having essentially equal surface areas of contact with the resistance and essentially equal coefficients of heat exchange and that are provided with respective inlet ports (112, 113) and with respective outlet ports (118, 119), the inlet ports being connectable as required through switching-valve means (16) to the source (17) supplying the compressed air for heating, while the two discharge ports of the said channels are connected, one to the utilizing appliance (21), for example to the heating unit, to the sealing unit, to the cutting station or to another cyclically operated utilizing appliance and the other discharge port is connected to an exhaust duct (19) that ends in any po

Abstract: A machine for the packaging of products with stretchable and thermoplastic film, comprising of a tubularization means comprising a tubular forming head device having an inlet and an outlet, for the tubularization of a wrapping film taken from a feeding bobbin and means for the longitudinal tight-seal welding of the superimposed edges of such tubularization film; means which alternate in the transversal grip of the head of the tubular wrapping which comes out from the tubularization means, which are pre-arranged for the longitudinal movement of the wrapping, to longitudinally stretch it and to perform on same at least two transversal, parallel and tight seal weldings, a transversal cut placed between the weldings and to retain the wrapping upstream and downstream of the two welded zones separated by the cut; means for the cyclical introduction of a product through the inlet of the tubularization means and through the outlet of the tubularization means thereby advancing the tubular wrapping film; means to tempo

Abstract: An upper jaw of the gripper is provided posteriorly to a fulcrum shaft, with opposed portions for a double effect cooperation with an eccentric element keyed on the shaft which controls the orientation of the gripper. The opening and closure movement of the gripper, in an appropriate phase of the distributor (D) of the film, is ensured by the cooperation of a roller of an action lever of the fulcrum shaft with a cam-function lever, horizontally fulcrumed with one end of a support fixed to the frame of the machine and provided on the other end with a trigger and hook device which, when actuated by the roller, deactivates and allows the lifting of the lever via an elastic return device. Subsequent to the lifting, the gripper closes and grasps the film from the distributor.

Abstract: A film folding and supplying apparatus for machines for packaging products with stretchable film comprising a pleating means for folding ends of a film traveling in a direction, to modify the width of the film in such a manner that the last edges of the film on the bottom of a product to be wrapped do not laterally project from the bottom of the product. The pleating means cooperates with rolling friction of the traveling film and comprises an elongate, flat and fixed guide having longitudinal edges with projecting rows of flat, idle and rounded edges wheels; and respective lateral guides having projecting rows of flat, idle and wheels with rounded edges which fold the film.

Abstract: The machine for the packaging of products with stretchable and thermoplastic film comprises:—Means for the tubularization of a wrapping film (5) taken from a feeding bobbin and means (6) for the longitudinal tight-seal welding of the super-imposed edges of such tubularized film;—Means (7, 7?) which alternate in the transversal grip of the head of the tubular wrapping which comes out from said tubularization means, which are pre-arranged for the longitudinal movement of said wrapping, to longitudinally stretch it and to perform on same two transversal, parallel and tight seal weldings, a transversal cut placed between the said weldings and to retain the wrapping upstream and downstream of the two welded zones separated by the cut,—Means (2, 3, 4) for the cyclical introduction of a product (P) through the inlet of said tubularization means (1) and up to its outlet;—Means (10) to temporarily support the packaging being formed;—Means (12, 12?) to stop the forward movement of the tubular wrapping on the outlet mou

Abstract: The machine for the packaging of products with stretchable and thermoplastic film comprises: Means for the tubularisation of a wrapping film (5) taken from a feeding bobbin and means (6) for the longitudinal tight-seal welding of the superimposed edges of such tubularised film; Means (7, 7?) which alternate in the transversal grip of the head of the tubular wrapping which comes out from said tubularisation means, which are pre-arranged for the longitudinal movement of said-wrapping, to longitudinally stretch it and to perform on same two transversal, parallel and tight seal weldings, a transversal cut placed between the said weldings and to retain the wrapping upstream and downstream of the two welded zones separated by the cut, Means (2, 3, 4) for the cyclical introduction of a product (P) through the inlet of said tubularisation means (1) and up to its outlet; Means (10) to temporarily support the packaging being formed; Means (12, 12?) to stop the forward movement of the tubular wrapping on the outlet

Abstract: The guiding means which provide to the pleating of the film (F) unwound from the bobbin and inserted in the packaging station, in order to adapt the width of the same film to the width of the products to be packaged, use rows of wheels (9, 9?, 15, 15?) to co-operate with the same film with rolling friction. The width of the pleated film may be adjusted by only adjusting of the reciprocal distance between the guides of lateral folding (13, 13?), and the corresponding rows of wheels (15, 15?). Before reaching between the folding guides, the packaging film runs on the convex portion of a transmission structure with an internal angle of about 170°, formed by a short central roller (5), and by long lateral rollers (105, 105?), all of them freely rotatable, which maintain the film transversally stretched and centered in correct manner on the following folding means.

Abstract: The apparatus comprises means (31, 33) for guiding and for holding the longitudinal edges of the film to be sealed so that they overlap with an intimate and distributed contact and comprises in an opposing position, a short distance from these guide means, a sealing head (6) made in good thermal insulator and with a low coefficient of friction in relation to the film, which directs onto the said film jets of hot air at an appropriate temperature and an appropriate pressure, through longitudinal slits of appropriate dimensions (35). The sealing head is connected to supply and control means (39-44) that keep it fully operational or have it promptly fully operational, the head being mounted on means (45) for moving it rapidly towards or away from the film to be sealed.

Abstract: The upper jaw (12) of the gripper is provided posteriorly to the fulcrum shaft (10), with opposed portions (112?, 15) for the double effect cooperation with an eccentric (19) with a single eccentricity, keyed on the shaft (17) which controls the orientation of the same gripper. On the fulcrum shaft (10) of the jaws of the gripper, upon which there is fixed the arm (127) of the lower jaw (27) of the same gripper, there are assembled needle springs (29, 29?) suitably pre-loaded, which with one end are integral to said shaft and with the other end anchored to the posterior fork (112) of the arm of upper jaw (112), in such a manner to urge in closure the two jaws of the gripper with a correct pressure.

Abstract: The machine is provided with means (6, 8, 9, 11″, 13) for the controlled feeding of the plastics film to the forming head (17) which forms with the said film a continuous and descending tubular winding, in which are inserted the products to be packaged by means of a hopper (18). A heat-sealing unit (22) performs a longitudinal and continuous sealing (Z) upon the longitudinal and reciprocally superimposed edges of the said tubular winding and downstream of the forming device (17) sealing and transversal cutting means (23) perform upon the same tubular winding at least a double transversal continuous tight-sealing, for the head-closing of the filled bag and for the sealing of the bottom of the following bag, while a cut between the two sealing, separates the consecutive bags between them. These means can also comprise an incision device to facilitate the following tear-opening of the bag.

Abstract: A stretch film presenting controlled permeability to gases, manufactured by process of balloon co-extrusion and consisting of outer layers (S2)of stretchable polymeric material and by one or two inner barrier layers (S3) of a EVOH based polymeric matrix, which is made stretchable by the addition of a suitable plasticizer in such a percentage as to conciliate the stretchability with the desired barrier effect, said layers of different material being reciprocally secured by means of layers (S4) of adhesive material. The polymeric matrix which forms the barrier material and the plasticizer are intimately mixed inside a double-screw corotating extruder, immediately before the phase of co-extrusion, through a premelting of the polymeric matrix and the subsequent injection of the plasticizer in liquid phase.

Abstract: The blade (12) which is to make the transverse cut of the film in the product packaging station is fixed in the lower part of the grooved section (11) which forms part of the front folder (9) of the packaging machine and has its cutting edge facing downwards. The film to be cut (102) is raised against this blade by a parallel grooved bar (13) with rounded and preferably staggered edges, which in an intermediate phase before its own working travel is also used to raise the section of the film which will have to be cut subsequently, to dispose the film in the correct position for gripping by the lateral grippers (6) of the packaging machine. The said film raising bar is preferably driven by means of a link block, by and electric motor (22) with electronic rotation speed and phase control, controlled by the processor of the packaging machine.

Abstract: A packaging machine which carries out the conventional packaging of products with a stretchable and gas-tight film is housed in a main chamber (1) which is seable and contains a modified and controlled atmosphere suitable for the conservation of the product to be packaged. The product enters and leaves the main chamber by passing through corresponding sealable airlock chambers (7, 8) provided with corresponding automatic doors (107, 207, 108, 208) and in any case designed to provide a seal with respect to the external environment and to the main chamber to which these chambers are attached. When the outer sides of the airlock chambers are opened, their inner sides are closed, so that the modified and controlled atmosphere cannot issue from the main chamber.

Abstract: The catches (10) of the brackets (5) which can be made inactive by the elevator when the elevator is in the low position are designed to interact with corresponding cams (20, 21, 22) of different angular extents, keyed to a shaft (17) which is driven by a motor (22) whose speed and phase are electronically controlled and which is supported rotatably by the base of the machine. When a product is fed onto the elevator and its dimensions are measured by known means which then determine the travel of the film unwinding gripper in the packaging station, if necessary the cam shaft is made to rotate through a distance capable of causing the oscillation of the catches of the brackets which are to be disengaged, so that when the elevator rises the unnecessary brackets are already disengaged and oscillate slowly downwards.