Machine for packaging with a single-fold heat-shrinkable film

Abstract: A product packaging machine with single-fold heat-shrinkable film of the type comprised of a body (11) into which there is formed a chamber (12), provided with a heat source and with a fan for the circulation of the air heated by such heat source and where, on the two sides of the upper edge of the chamber there are mounted blades (13,14) for cutting and heat-sealing the film. The above chamber is closable through a hinged bell (15), so as to determine a single space for the cutting, heat-sealing and heat-shrinking of the film. According to the invention, the machine is provided with a plurality of idle rollers (18), adapted to function as support and transport plane for the above product, for its discharge through gravity.

Description: Object of the present invention is a product packaging machine with single-fold heat-shrinkable film. Machines are known that allow packaging various products into a single-fold heat-shrinkable film. Incidentally, it must be noted that the expression "single-fold film" indicates a film longitudinally folded on itself so as to determine two superimposed edges. Known packaging machines, for example, consist of a body into which there is formed a chamber provided with a heat source and with a fan for the circulation of the air heated by such heat source. On the two sides of the upper edge of the chamber there are mounted blades for cutting and heat-sealing the film. The chamber is closable through a hinged bell, so as to determine a single space for the cutting, heat-sealing and heat-shrinking of the film. Moreover, the chamber is provided with a grid for supporting the product during packaging. The product to be packaged is inserted between a work surface (arranged at the side of the grid, outside the bell) and the upper edge of the single-fold film, and it is carried on the grid enclosed between two stripes or edges of film. The bell is lowered, and such lowering concurrently causes the actuation of the cutting/heat-sealing blades, of the heat source resistances, and of the hot air circulation fan. The single-fold film is thus cut and heat-sealed around the product so as to form a closed wrapping, and it is shrunk on it thanks to the circulation of hot air into the chamber and the bell. The machine is now ready for a successive packaging operation, identical to that briefly described above. A bell machine of this known type is described and illustrated, for example, in US-4.104.848. Even though packaging machines of the described type are capable of performing the function they have been designed for, they could be subject to some interesting and important improvements. In fact, it must be noted that in the described use of the packaging machine, at the end of a packaging operation it is necessary to remove from the support plane, and in particular from the grid (through a manual operation directed in normal direction to the longitudinal axis of the machine) the packaged product before starting a new packaging operation. Actually, there exist also automatic machines where in place of the grid there is provided a conveyor belt for discharging the package. The bell motion and the belt actuation are automated in an intermittent manner. Such machines are fast but they certainly are very expensive and thus, only adapted for large productions. Furthermore, US-A-3 496 700 discloses a packaging machine of the type comprising a heat-shrinking tunnel and a transport path formed by idle rollers. Purpose of the present invention is that of realising a product packaging machine with single-fold heat-shrinkable film which should allow a higher production efficiency even though without a considerable cost increase. A further purpose of the invention is that of realising a packaging machine which should allow an improved use comfort. These and other purposes are achieved by a product packaging machine with single-fold heat-shrinkable film according to claim 1. Further features of the invention are defined in the dependent claims . Further purposes and advantages of the present invention will appear clearly from the following description and attached drawings, provided by way of an explicative and non-limiting example. In such drawings: Figure 1 shows a perspective view of a product packaging machine with single-fold heat-shrinkable film according to the present invention; Figure 2 shows a perspective view of a detail of the packaging machine of figure 1; and Figures from 3 to 9 show the sequence of an operating cycle of the packaging machine illustrated in figures 1, 2. With particular reference to figures 1 and 2, the product packaging machine with single-fold heat-shrinkable film is indicated in its whole with reference numeral 10. The structure of the product packaging machine with single-fold heat-shrinkable film is not described in detail since it is in se well known in the prior art (reference shall be made to US-4.104.848); only the functional elements useful for understanding and implementing the invention are referred to in the present application. In synthesis, machine 10 exhibits a body 11 inside which there is determined a chamber 12, in turn provided with a heat source and with a fan for the circulation of the air heated by said heat source (heat source and fan not shown). On the two sides of the upper edge of chamber 12 there are mounted blades 13 and 14, respectively longitudinal and transversal, for cutting and heat-sealing the film, and chamber 12 is closable through an overhanging hinged bell 15, so as to determine a single space for the cutting, heat-sealing and heat-shrinking of the film. Corresponding opposed counter-blades 16 and 17 are present on bell 15. Characteristically, moreover, machine 10 of the invention exhibits a plurality of idle rollers 18, adapted to function as support, transport and discharge surface for products 19 and 20. In particular, the idle rollers 18 form a path exhibiting a first plane portion 21, corresponding to the heat-sealing area, and a second inclined portion 22, arranged on a side 23 of machine 10, which can be referred to as plane of product discharge through thrust and gravity. The inclination of the inclined portion 22 of idle rollers 18 can be adjusted: in fact, on the corresponding side 23 of machine 10 there is present a plate 24, provided with a support surface 25 and with screws 26 and 27, which engage into respective slots 28 and 29. The height of such plate 24 can thus be adjusted at pleasure, within a predetermined interval, so that the same plate 24 may function as support surface for the inclined portion 22 of the idle rollers 18. Moreover, the height of the idle rollers 18, and in particular of the horizontal portion 21 of the same, can be adjusted through a system of uprights or racks 30 and 31, provided with relevant engagement means so as to allow the packaging of products 19 and 20, having a considerable height dimension, such as for example packages of mineral water bottles or other relatively high products. The operating sequence of machine 10 (figures 3-9) is as follows: a product 19 is packaged according to substantially known methods, that is to say, it is inserted between the work surface P and the upper edge of the single-fold film (figures 3, 4). Product 19, partly wrapped into the two edges of the single-fold film is manually moved, jointly with the same film, to the position of figure 5, on the horizontal portion 21 of the idle rollers 18, below bell 15. Bell 15 is now manually lowered to the position of figure 6 and such lowering concurrently causes (in a per se known manner) the actuation of the heat-sealing blades 13, 14, and the circulation, through fan, of the air heated by the heat source. The single-fold film is thus cut and heat-sealed around product 19 so as to form a closed wrapping, shrunk on it thanks to the circulation of hot air into chamber 12 and bell 15, which can thus be lifted to the position of figure 7. At this point, leaving the already packaged product on the idle rollers 18, a new product 19 to be packaged is introduced into the machine (figure 8). As a consequence, upon the execution of the previous operating steps described with reference to figures 4, 5, the already packaged product, indicated with the reference numeral 20, is manually pushed (laterally) along the sliding direction defined by the idle rollers 18 (figure 9), thus, along a reduced-friction surface and, thanks to the inclined portion of the same rollers it is automatically discharged through gravity from the working area of the packaging machine 10, to be further handled. It must be noted that the described system allows obtaining at low costs an extreme comfort and rapidity of machining. The described system of rollers 18 can also be applied to automatic packaging machines, not of the bell type but exhibiting a heat-shrinkage tunnel downstream of the heat-sealing and cutting area, thus allowing an easy and automatic access of the products to be packaged in such heat-shrinkage tunnel. The features of the product packaging machine with single-fold heat-shrinkable film object of the present invention, as well as its advantages, are evident from the above description. Finally, it is clear that several variants can be made to the product packaging machine with single-fold heat-shrinkable film object of the present invention without departing from the scope of the invention as defined in the claims. It is also clear that, in the practical embodiment of the invention, materials, shapes and sizes of the illustrated details can be of any type according to the requirements.

Claims: Product packaging machine with single-fold heat-shrinkable film consisting of a body (11) housing a cutting and heat-sealing frame, and a chamber (12) for shrinking through circulation of hot air, the chamber (12) being closable through a bell (15), hinged on a first side of the body (11), so as to determine a single space for the cutting, heat-sealing and shrinking of the film, characterised in that it is provided with a surface (21, 22) for supporting and discharging the products (19, 20) in a longitudinal direction parallel to said first side, the surface (21, 22) being provided with a plurality of idle rollers (18) adapted to function as support and transport plane for the products (19, 20), said idle rollers (18) forming a path exhibiting a first horizontal portion (21) corresponding to the working area of the machine (10) and a second inclined portion (22) arranged on a second side (23) of the body (11) transversely to said first side, wherein the inclination of the inclined portion (22) of the idle rollers (18) is adjustable through a plate (24) provided with a support surface (25) and with screws (26, 27) which engage into respective slots (28, 29) for the purpose of adjusting the height of the plate (24). Machine (10) according to claim 1 , characterised in that the height of the horizontal portion (21) of the idle rollers (18) can be adjusted through a system of racks (30, 31) and engagement means or equivalent, so as to allow the packaging of products (19, 20) exhibiting a considerable height size. Machine (10) according to claim 1, characterised in that the shrinking chamber (12) is provided with a heat source and with a fan for the circulation of the air heated by said heat source. Machine (10) according to claim 1, characterised in that said plurality of idle rollers (18) adapted to function as support and transport plane for the products (19, 20) comprises portions hinged with one another.

Inventors: BUTTURINI LUCIANO, BUTTURINI, LUCIANO
Applicants: ITALDIBIPACK SPA, ITALDIBIPACK S.P.A.
Application year: 2001
Main classification: B65B9
IPC codes: B65B9