HORIZONTAL PACKAGING MACHINE, IN PARTICULAIR FOR FORMING, FILLING AND SEALING BAGS WITH VARIOUS PRODUCTS

Abstract: A packaging machine, in particular for forming and filling bags with various products using a film (2) of flexible material wound on a reel (3), comprises a main supporting frame (4) with a longitudinal axis (L) which supports means (5) for controllably unwinding the film (2) means (10) for conveying the continuous strip (8) along the longitudinal axis (L), loading means (14) operationally associated with the continuous strip (8) for loading it at intervals with the products to be packaged, a first welding station (15) for continuously welding the adjacent side edges (9) of the strip (8) so as to confer to it a tubular shape a second welding station (20, 20') comprising one or more welding plates (22) moved about a transverse axis (A) so as to pass over, in contact therewith, the upper surface of the continuous strip (8), forming transverse welds (8) between its upper portion (8') and its lower portion (8"). The conveying means comprise a conveyor belt (10), which extends through the second welding station (20, 20'), supporting the continuous strip (8) with the products to be packaged.

Description: HORIZONTAL PACKAGING MACHINE, IN PARTICULAIR FOR FORMING, FILLING AND SEALING BAGS WITH VARIOUS PRODUCTS Field of the invention The present invention relates to a machine for forming and filling bags with products of various kinds and dimensions, particularly suitable for use in the sector of packaging machines. Background art As is known, packages containing products of various kinds which are packed in bags generally made of plastic are extremely widespread in commerce. In order to package these products, at present, in accordance with the known art, special packaging machines are used, which machines essentially comprise a frame which supports means for feeding a strip of plastic, automatic or semi-automatic means for loading the products to be packaged, means for forming bags from the strip of plastic and means for closing the bags. In particular, a type of packaging machine is known, in which a reel of film consisting of plastic material, generally polyethylene, is unwound onto a horizontal conveyor belt on which the products to be packaged are placed. Then, the longitudinal edges of the strip are brought together on top of one another so as to obtain a long sheet which is folded in half and are then welded longitudinally along their superimposed edges by means of a first longitudinal welding station. Pairs of counter-rotating rubber rollers are generally arranged before and after this first station, which rollers press against the superimposed edges of the strip, feeding it through the first welding station so as to keep it perfectly taut. The strip containing the products to be packaged then reaches a second welding station which closes and separates the individual packages by means of welds transverse to the direction of feeding of the strip. Obviously, the product loading means, the conveyor belt, the peripheral speeds of the rubber rollers and the welding means associated with the two stations are synchronised with each other so as to ensure correct operation of the packaging machine. At present, in these types of machines of the known type, the conveyor belt is interrupted at the point of entry into the second welding station and is then, if necessary, continued by a second conveyor belt which is positioned after the second welding station so as to facilitate discharging of the packed products from the packaging machine. The interruption of the conveyor belt before the second welding station is made necessary by the fact that, at present, the transverse welding of the bags is performed using welding means which act simultaneously above and below the plastic strip and which cannot operationally envisage the arrangement of a conveyor belt in between. Generally, in fact, the transverse welding means comprise one or more welding plates which are mounted above the plastic strip on a first support structure rotating about a first transverse axis, and one or more counter-rollers which are mounted underneath the plastic strip on a second support structure rotating about a second transverse axis, parallel to the first axis, which rollers act as means for opposing the welding plates during the transverse welds performed on the plastic strip. Therefore, in these known machines, the plastic strip already welded longitudinally passes into the transverse welding station where it is retained between a welding plate which, rotating, moves downwards into contact with the upper surface of the strip and a counter-roller which, rotating, moves upwards into contact with the bottom surface of the strip. Generally the compressive action which is produced between the contact surface of the welding plate and the counter-roller also produces the separation of the package thus obtained from the remaining plastic strip. In practice, the packaging machines of the known type, which are briefly described above, have numerous drawbacks. A major drawback consists in the fact that, along the section between the end of the conveyor belt and the station for transverse welding of the strip, the products are not sufficiently supported and may cause depressions in the strip which result in imperfect welding. An undesirable displacement of the product on the strip may also occur, resulting in its positioning, during welding, between the welding plate and the counter-roller, such as to cause stoppage of the machine. This drawback is accentuated even more in the case of packaging of small- size, heavy, metal fittings. Until now, moreover, if it is required to insert into a single package products of a different kind such as, for example, a handle or a bracket together with the fittings necessary for assembly, keeping them, however, separate from each other, it has been necessary to perform two separate packaging operations. More precisely, it has been necessary to envisage a first packaging step for packing a first kind of product, for example metal fittings, and then a second packaging step for packing a second kind of product, for example a tool or implement, together with the package containing the first kind of product. In this way, a single package containing inside it two different kinds of products separated from each other is obtained. However, this method of packaging products of different kinds is extremely uneconomic in that it does not allow the products to be packaged with one pass of the plastic strip through the welding stations. This increases considerably the packaging time and constitutes an additional cost which negatively affects the operating performance of the entire packaging process. Summary of the invention The main object of the present invention is therefore to eliminate the drawbacks mentioned above, by providing a packaging machine for forming and filling bags with products of various kinds, which allows products of any dimensions and weight to be packaged in an optimum manner, suitably supporting them during the welding steps. Another object of the present invention is to provide a packaging machine which allows products of different kinds to be packaged separately by means of a single pass of a plastic strip through the welding stations. Another object of the present invention is to provide a packaging machine which is constructionally simple and operationally entirely reliable. These objects and others are all achieved by the packaging machine of the aforementioned type, in particular for forming and filling bags with various products using a film of flexible material wound on a reel, comprising a load- bearing frame with a longitudinal axis which supports: means for controlled unwinding of the film so as to form a continuous strip with parallel side edges, means for conveying the continuous strip along the longitudinal axis L, loading means operationally associated with the continuous strip for loading it at intervals with the products to be packaged, guide means for bringing together the side edges of the continuous strip, arranging them on top of one another, a first strip welding station for continuously welding the adjacent side edges thereof, conferring to the strip a tubular shape with an upper portion and a lower portion arranged facing each other and separated at intervals by the products to be packaged, a second welding station comprising one or more welding plates moved about a transverse axis so as to pass over, in contact therewith, the upper surface of the continuous strip, forming transverse welds between the upper portion and the lower portion of the continuous strip, characterized in that the conveying means comprise a conveyor belt which extends through the second welding station, supporting the continuous strip containing the products to be packaged. Owing to this arrangement, the machine is able to support in an optimum manner the products to be packaged during the welding steps and in addition allows easy packaging separately of products of different kinds. Brief description of the drawings Further feature and advantages will be more clearly understood in the light of the detailed description of a packaging machine according to the invention which follows, provided with reference to the accompanying drawings which show a purely exemplary and non-limiting embodiment thereof and in which: FIG. 1 shows a front view of the packaging machine according to the present invention; FIG. 2 shows a plan view of the packaging machine according to Fig. 1 ; FIG. 3 shows a side view of the packaging machine according to Fig. 1 . Detailed description of a preferred example of embodiment With reference to the accompanying drawings, the packaging machine according to the present invention has been indicated in its entirety by 1 . The machine may be advantageously used for forming and filling bags of plastic material with products of various kinds using a film 2 of flexible material wound onto a reel 3, as can be seen from Figs. 1 and 3. In particular, as will be clarified below, the machine 1 is suitable for packaging various products, keeping separate the different kinds of said products inside a single package. For example, it will be possible to package in one bag one or more handles together with the metal fittings necessary for assembly thereof, keeping the fittings separate from the handles. The packaging machine 1 essentially comprises a main supporting frame 4 which extends structurally and operationally along a longitudinal axis L and supports in the bottom part means 5 for controllably unwinding of the film 2. Therefor means 5 comprise, in turn, a reel-carrying drum 6 which supports the flexible film 2 wound onto the reel 3 and tensioning means 7 able to control tensioning of the film 2. Once unwound from the reel 3, the film 2 forms a continuous strip 8 with parallel side edges 9. The film 2 is moved along the longitudinal axis L by conveying means, preferably consisting of a continuous conveyor belt 10, the ends of which are operationally associated with an entrance way 1 1 and an exit way 1 2 to/from the machine 1 . At the entrance way 1 1 , the side edges 9 of the strip 8 pass through the guide means essentially consisting of a metal plate 1 3 folded in the form of a U. In this way, when the strip 8 passes through the plate 1 3 automatically directs its side edges 9 upwards, bringing them closer together. At the entrance way 1 1 , loading means 1 4 are also provided, said means being operationally associated with the strip 8 so as to load it in a discontinuous manner and at predetermined distances with the products to be packaged (not shown in the drawings). A first station 1 5 for welding the strip 8 is mounted on the main frame 4 of the machine 1 , downstream of the guide means 1 3, said station being able to weld together in a continuous manner the side edges 9 of the strip 8 so as to shape the latter substantially in the form of a tube. More precisely, upstream and downstream of the first station 1 5, two pairs of motorized and counter-rotating rubber rollers 1 6 and 1 7 are arranged, said rollers pressing against the superimposed edges of the strip 8, feeding it through the first welding station 1 5 so as to keep it perfectly taut. In particular, the first pair of rollers 1 6 also performs the function of superimposing the side edges 9 of the strip 8 previously brought together and directed upwards by the guide means 1 3. Advantageously, suitable longitudinal welding means 1 8 may be provided inside this first station 1 5, said means for example consisting of a pair of injectors 1 9 able to insufflating air at a high temperature onto both sides of the adjacent edges 9 of the strip 8. At this point, having passed through the first welding station 1 5, the strip 8 has at the top a continuous weld which provides it with a substantially tubular form inside which the products to be packaged are housed at intervals. The tubular shape of the strip 8 is defined more particularly by an upper portion 8' and a lower portion 8" facing each other and separated at intervals by the products to be packaged. A second welding station 20 is mounted on the main frame 4 of the machine 1 downstream of the first welding station 1 5, being able to close and separate the individual packages by means of welds transverse with respect to the direction of feeding of the strip 8. Transverse welding means 21 are provided inside the second welding station 20, said means comprising one or more welding plates 22 mounted above the strip 8 on a first support structure 23 moved about a first transverse axis A and one or more counter-members 24 mounted underneath the strip 8 on a second support structure 25 moved about a second transverse axis A' parallel to the first axis A. In operation, the plastic strip 8 already welded longitudinally passes through the second welding station 20 where it comes into contact with a welding plate 22 which, rotating, moves downwards into contact with the upper surface of the strip 8. At the same time, in accordance with a preferred embodiment of the present invention illustrated in the accompanying figures, a counter-member 24 synchronised with the movement of the welding plate 22 and rotating moves upwards into contact with the bottom surface of the strip 8 and in this way acts as an opposing means for the welding plate 22 so to perform the transverse weld on the strip 8 between the upper portion 8' and the lower portion 8" . According to the invention, the conveyor belt 10 passes through the second welding station supporting the strip 8 with the products to be packaged. In accordance with the embodiment described above and illustrated in the figures, the conveyor belt 1 0, during the transverse welds, remains physically positioned in between the counter-members 24 and the welding plates 22. Advantageously, the counter-members 24 consist of silicone rollers, the strip 8 consists of polyethylene and the conveyor belt 1 0 is made of a material such as teflon, able to allow separation of the strip 8 from its upper surface after the welds have been performed. In accordance with a constructional variant of the present invention, the said conveyor belt 1 0 operates directly as an opposing member for the welding plates 22 inside the second welding station 20 for performing the transverse welds. In accordance with a further characteristic feature of the present invention, the packaging machine 1 comprises two separate second welding stations 20, 20' each of which performs correspondingly separate transverse welds able to divide up different kinds of products loaded along the strip by the loading means 14. In greater detail, the first 20 of the two second welding stations performs on the strip 8 transverse welds in a middle position on the packaging so as to divide it into two separate compartments inside which products of different kinds may be separated. The second station, on the other hand, performs the closing weld and, for example by means of greater compression of the strip 8, also produces separation of the finished package from the remaining strip 8. According to the invention, the conveyor belt 1 0 extends horizontally along an upper section 26 operationally associated with the welding stations 1 5, 20 and 20' and comprises an entry portion 26' associated with the guide means 1 3 and the loading means 14 and an exit portion 26" which extends from the latter 20' of the second welding stations to the exit way 1 2 of the machine. This latter belt portion allows easy extraction of the finished packages from the machine 1 . The movable conveyor also extends along a bottom section 27 without passing through the welding stations 1 5, 20 and 20'. For this purpose, the belt 1 0 is wound endlessly around two motorized rollers 28 and 29 and numerous idle rollers all mounted on the main frame 4 of the machine 1 . In order to avoid slippage effects, preferably both the end rollers 28 and 29 on which the conveyor belt 1 0 is wound are motorized. In greater detail, the motorized roller 28 is arranged at the entrance way 1 1 of the machine, while the motorized roller 29 is arranged at the exit way 1 2 of the machine 1 at the end of the exit portion 26" of the upper section 26. In accordance with the example of embodiment according to Figure 1 , the idle rollers comprise four drive rollers 30 able to feed the belt outside of the welding stations 1 5, 20 and 20'. The invention thus conceived therefore achieves the intended objects. Obviously it may also assume, during its practical implementation, forms and configurations different from that illustrated above without, thereby, departing from the present scope of protection. Moreover, all the details may be replaced by technically equivalent elements and the dimensions, the forms and the materials used may be of any nature according to requirements and in particular may be made of either plastic or metal.

Claims: CLAIMS 1 . Packaging machine, in particular for forming and filling bags with various products using a film (2) of flexible material wound on a reel (3), comprising a main supporting frame (4) with a longitudinal axis (L) which supports: - means (5) for controlled unwinding of said film (2) so as to form a continuous strip (8) with parallel side edges (9); - means (10) for conveying said continuous strip (8) along said longitudinal axis (L); - loading means ( 1 4) operationally associated with said continuous strip (8) for loading it at intervals with products to be packaged; - guide means (1 3) for bringing together the side edges (9) of said continuous strip (8), arranging them on top of one another; - at least one first welding station (1 5) for continuous welding of the adjacent side edges (9) of said strip (8) so as to confer to it a tubular shape with an upper portion (8') and a lower portion (8") arranged facing each other and separated at intervals by said products to be packaged; - at least one second welding station (20, 20') comprising one or more welding plates (22) moved about a transverse axis (A) so as to pass over, in contact therewith, the upper surface of said continuous strip (8), forming transverse welds (8) between said upper portion (8') thereof and said lower portion (8") thereof; characterized in that said conveying means comprise a conveyor belt (1 0), which extends through said second welding station (20, 20'), supporting said continuous strip (8) with the products to be packaged. 2. Packaging machine according to Claim 1 , characterized in that said conveyor belt (1 0) defines an opposing member for the welding plates (22) during the execution of said transverse welds inside said second welding station (20, 20'). 3. Packaging machine according to Claim 1 , characterized in that said second welding station (20, 20') comprises one or more counter- members (24) which are mounted underneath said conveyor belt (1 0). 4. Packaging machine according to Claim 3, characterized in that said one or more counter-members (24) are moved about a transverse axis (A') parallel to the axis (A) and operate as an opposing member for the welding plates (22) during the execution of said transverse welds. 5. Packaging machine according to Claim 4, characterized in that said conveyor belt (10) is positioned, so as to make contact, between said counter-members (24) and said welding plates (22). 6. Packaging machine according to Claim 1 , characterized in that it comprises at least two separate welding stations (20, 20'), each of which performs correspondingly separate transverse welds able to divide up different kinds of products loaded on said continuous strip (8) by said loading means (14). 7. Packaging machine according to Claim 6, characterized in that at least one of said second welding stations (20, 20') is adapted to perform the separation of the bag containing the product from the remaining continuous strip (8). 8. Packaging machine according to Claim 1 , characterized in that said conveyor belt (1 0) extends horizontally along an upper portion operationally associated with said first welding station (1 5) and second welding station (20, 20'), supporting and moving said continuous strip (8) and said products to be packaged. 9. Packaging machine according to Claim 1 , characterized in that said conveyor belt (10) extends along a bottom section (27) outside of said welding stations (1 5, 20 and 20'). 1 0. Packaging machine according to Claim 1 , characterized in that said conveyor belt (1 0) is wound endlessly around at least one motorized roller (28) and at least one idle roller (29). 1 1 . Packaging machine according to Claim 9, characterized in that said conveyor belt (10) is wound endlessly around at least one motorized roller (28) and a plurality of idle rollers (30) able to drive the bottom section (27) of said conveyor belt (10) outside of said welding stations (1 5, 20 and 20'). 1 2. Packaging machine according to Claim 1 , characterized in that said film is made of polyethylene. 1 3. Packaging machine according to Claim 1 , characterized in that said conveyor belt is made of a non-adhesive material, such as teflon.

Inventors: ZANELLA MARIA TERESA, ZANELLA, MARIA, TERESA
Applicants: COMIPACK S R L, ZANELLA MARIA TERESA, COMIPACK S.R.L., ZANELLA, MARIA, TERESA
Application year: 2001
Main classification: B65B9
IPC codes: B65B9