TECHNICAL FIELD OF THE INVENTION
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The present invention relates to packaging for fruit and vegetables and similar items, designed to reduce environmental impact.
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Specifically, it concerns a packaging that improves recycling, optimizes operating costs, and specifically eliminates the use of mechanical closures or reinforcements.
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The packaging according to the present invention maintains the quality of the packaging, ensuring adequate load capacity, durability, and the option of including a customized label. The present invention also relates to a packaging machine for producing such packaging.
PRIOR ART
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Packagings for fruit and vegetables and similar products, as well as other types of products, in the form of a bag suitable for containing products such as citrus fruits, tubers, bulbs, chocolate coins, cheeses, cured meats, children's marbles, and so on, are known.
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These packagings, described for example in patents
IT1168656B ,
IT1258141B (
BO1992A000313 ), and
ITBO1996A000198 , are generally composed of tubular mesh sections made of traditional or compostable thermoplastic and cellulose materials. The closure is secured by two metal clips, while a customized paper or plastic label is used to provide essential product information. The label may include product information, nutritional information, shelf life and expiration information, logos, product codes, and other commercial information.
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These packagings do not comply with the requirements of the new European packaging regulations because they combine three different materials that cannot be separated manually, plastic for the mesh packaging, metal for the closing clips, and paper for the label, making the packaging non-recyclable.
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In cases where the label is plastic and therefore the packaging uses two materials-plastic mesh and label, and metal clips-these materials are still too many to comply with the current packaging regulation.
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Following these guidelines, in recent years, some single-material solutions using plastic clips have been introduced to improve recyclability, as described, for example, in patent documents
US2009/081934A1 ,
ES1305762U , and
US2022/227516A1 .
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However, these solutions have significant limitations: plastic clips are less durable, limiting the weight of packaged products compared to current packaging; they require greater weight of plastic material as they must be made thicker than metal clips; and packaging machines for packagings with plastic clips have less operating autonomy because plastic clips are bulkier than their metal counterparts, requiring more frequent refilling and resulting in increased machine downtime, thus reducing operational efficiency during packaging.
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Furthermore, plastic clips and their feeding and closing systems are significantly more expensive than traditional solutions because simply updating the packaging closing unit is often not possible, requiring a complete replacement of the packaging machine.
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Patent
EP2078682B1 describes a net bag for fruit and vegetables consisting of a tubular plastic mesh element, such as woven, extruded, or similar mesh, and lateral laminar plastic strips joined to the mesh of the tubular element by heat-welding, forming closures that include a wrap-around association between the ends of the tubular mesh element and the ends of the laminar strip, so that the strip and the tubular mesh element fold back on themselves transversally, and wherein the heat-welding seams are arranged transversely to the longitudinal axis of the bag, forming a continuous line or a line with discontinuous sections that extend across the entire width of the laminar strip.
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In this case, even if the clip has been eliminated, the packaging requires a greater amount of material than known packagings with the ends gathered in a cord, with the ends formed by the mesh and the strip folded back on themselves.
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Additionally, the ends must be of a certain width to achieve a strong weld, and the process of forming folded ends is more complicated than for packagings with gathered ends.
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Patent
US8365506B2 describes an apparatus for closing mesh bags, particularly applicable to tubular mesh bags made of heat-weldable material, wherein a longitudinal portion of narrow mesh is compressed together with at least one portion of plastic strip, to which it is subsequently attached by melting the materials constituting the mesh and the strip.
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In this case, the technique adopted involves welding between the mesh casing and two plastic strips, along two dedicated attachment sections.
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Specifically, the welding occurs using a special fork-shaped head, which branches into two distinct terminals within which a cutting blade slides to separate the two mass-produced packagings.
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However, the large surface area of the packaging involved in the welding process increases cooling time and the welding process execution time, thus slowing productivity, as well as increasing costs arising from material procurement and the welding process itself.
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Furthermore, there is an inevitable ecological penalty, given the consumption of a huge quantity of plastic material required to produce the aforementioned net bags.
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There is therefore a clear need to develop eco-friendly packaging that allows for the inclusion of personalized product information, reduces the use of plastic materials, improves end-of-life packaging disposal, while ensuring packaging machines with adequate load capacity and high productivity.
OBJECTS OF THE INVENTION
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The technical aim of this invention is therefore to develop a packaging for fruit and vegetables that requires no additional components to connect the product container to the label, eliminating the use of metal or plastic clips or reinforcements, thus making the packaging a single-material product, consisting solely of the plastic mesh and label.
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Furthermore, the mesh and label are also made from the same thermoplastic material, whether virgin or recycled, i.e., from recycled sources, recyclable, compostable, or biodegradable, or materials that are compatible with each other during disposal.
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This simplifies the disposal of the packaging without the need to separate the packaging materials.
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With the packaging according to this invention, the use of new raw materials is limited; in fact, at the end of its life, the packaging material can be easily reused, thus contributing to an overall reduction in environmental impact.
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A further object of the present invention is to develop a packaging that reduces production costs and packaging lead times.
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This aim and this object are achieved by the packaging for fruit and vegetables according to the attached claim 1.
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Further advantageous features are described in the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS.
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The features of the invention will be better understood by anyone skilled in the art from the following description and the accompanying drawings, given as non-limiting examples, in which:
- Figure 1 is a front view of one embodiment of a packaging for fruit and vegetable products according to the present invention;
- Figure 2 is a side view of the packaging of Figure 1;
- Figure 3 is a rear perspective view of the packaging shown in the preceding figures;
- Figure 4 is a rear view of the packaging shown in the preceding figures;
- Figure 5 is a front view of another embodiment of a packaging for fruit and vegetable products according to the present invention;
- Figures 6 and 7 illustrate a label for the packaging shown in Figures 1-4, in front and perspective views, respectively;
- Figure 8 illustrates a label for the packaging shown in Figure 5, in front view;
- Figures 8A and 8B illustrate two sequences for forming the label for the packaging shown in Figure 1, in front view;
- Figure 9 schematically illustrates a sequence for closing one end of the packaging according to the present invention;
- Figure 10 illustrates some possible cross-sections of a detail of the closing device for the packaging according to the present invention;
- Figure 11 schematically illustrates some details of the welding of a label according to one embodiment of the present invention;
- Figure 12 schematically illustrates some details of the welding of a label according to another embodiment of the present invention;
- Figure 13 is a perspective view of a closing and welding unit of the machine for producing the packaging for fruit and vegetables according to the present invention;
- Figure 14 is an enlarged view of the closing and welding unit of the machine for producing the packaging for fruit and vegetables shown in Figure 13, with the packaging in the closing step;
- Figures 15 and 16 are enlarged perspective views of some details of the closing and welding unit of the machine for producing the fruit and vegetable packaging of Figures 13 and 14;
- Figures 17 and 18 are enlarged perspective views of a device forming part of the closing and welding unit of the machine for producing fruit and vegetable packaging according to the present invention; and
- Figure 19 is an enlargement of the upper portion of Figure 2, which shows the version of the invention incorporating circular holes containing the welds located along their respective edges, shown schematically.
EMBODIMENTS OF THE INVENTION.
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With reference to the attached figures, reference numeral 1 generally designates a packaging for fruit and vegetable products, according to an embodiment of the present invention.
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The packaging 1 for fruit and vegetable products comprises at least one tubular wrapper 2, for example, a tubular netting made of woven or extruded thermoplastic material, for containing fruit and vegetable products A; the wrapper 2, once filled with products A, has a substantially sack-like shape with a continuous side wall 3, an upper end 4, and a lower end 5 of the material of the wrapper 2 gathered in a cord.
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In turn, the ends 4, 5 gathered in a cord are enclosed within a respective upper band 6 and a respective lower band 7; A flag-type label 8 may include the upper band 6.
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Figure 5 shows another version of packaging 1, according to the present invention, including a continuous type label 9, also known as C2C or clip-to-clip; in this version, the label 9 is continuous, including and connecting the upper band 6 and the lower band 7.
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Figures 6 and 7 show the flag-type label 8 in detail, in front and perspective views, respectively.
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Label 8 includes the upper band 6 and a portion 10 containing writing, drawings, or other information relating to the product contained in the packaging 1.
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Specifically, portion 10 may feature on one side text or drawings 11 for displaying information, general wording, commercial data, the manufacturer's logo(s), product name, manufacturer's brand(s), product codes, and other data.
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According to one version of the present invention, the portion 10 may feature on one side, for example, the outside, the aforementioned text or drawings 11 for information about the product: name, brand, logo, etc., while on the other side, for example, the inside as illustrated in Figure 4, it may feature variable information 12 relating to the product contained in the packaging: weight, batch, expiration date, barcode, etc.
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The label 8 comprises the upper band 6 connected to the portion 10; as can be seen from
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Figure 6, and as will be explained in detail below, the lower band 7 is made, following a cut along a line 13 (figure 6) on the upper band 6, in the packaging that is being formed in sequence to the closing step of the previous packaging.
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Furthermore, the first portion 10 is partially separated from the band 6 by two substantially transverse and/or slightly oblique incisions or creases 14.
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As shown, for example, in Figure 7, where the band 6 is partially folded, these incisions or creases 14 allow the portion 10 to be maintained in a substantially flat configuration, thus ensuring better readability of the data on it even when the band 6 is folded around the end 4 to close it.
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In a substantially median longitudinal position, the bands 6, 7 may include pre-cuts or partial creases 15 so as to facilitate, during the closing and welding step, a bending of the bands themselves around the ends 4, 5 gathered in a cord of the wrapper 2 in the intended median position, thus allowing for an effective and resistant closure.
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Figure 8 illustrates the continuous, or C2C, or clip-to-clip, label 9, which, as mentioned, comprises and is connected to both the bands 6 and 7. In this case, too, the bands 6 and 7, in a substantially longitudinal median position, may include pre-cuts or creases 15, at least partially, for the reasons explained above to facilitate folding.
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In this case, too, the label 9 comprises a portion 16, larger than the portion 10 of the label 8, with writing and other information; as in the previous case, this portion 16 is partially separated from the bands 6 and 7 by respective substantially transverse and/or slightly oblique incisions or creases 14, to maintain the portion 16 in a substantially flat configuration for better readability of the data present even when the bands 6 and 7 are folded around their respective cord-enclosed ends 4 and 5.
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In particular, the portion 16 may feature on one side, for example the external side, writings or drawings 17 for the presentation of product information, general wording, commercial data, manufacturer's logo, product name, manufacturer's brand or brands, product codes, and other data, while on the other side it may feature variable information relating to the contents of the packaging: weight, batch, expiry date, bar code, etc.
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Figures 8A and 8B illustrate other versions of the label 8, one shaped like a flag and a more economical ribbon-shaped alternative, which form a tape 28; Figure 8B features markings 9A intended to provide a signal for the dispensing of the tape 28 along the length specified for the label type.
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Furthermore, different label sizes and shapes are also possible, all of which fall within the scope of the present invention.
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According to the present invention, the wrapper 2 is made of tubular mesh, extruded or woven, in traditional thermoplastic material that is recyclable, compostable, or biodegradable; the label 8, 9 is also made of the same traditional thermoplastic material that is recyclable, virgin, or recycled, i.e., plastic material with polymers from recycled sources, or compostable or biodegradable.
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The wrapper 2 and the label 8, 9 are always made of materials that are compatible with each other so as to make the packaging 1 easily recyclable, compostable or biodegradable.
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An important feature of the present invention is the type of welding performed in the packaging 1.
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As can be seen in Figures 2, 3, and 11, the welding of the bands 6, 7 folded around the respective ends 4, 5 enclosed in a bead is performed using one or more welding points 18 made using the same bands 6, 7.
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It should be noted that, according to one version of the present invention, the welding points 18 are through-holes (see Figure 11, which will be described in detail below) obtained by contact and/or the passage of hot elements, for example, with suitable punches 19 heated by suitable heating means, for example, by electrical resistances or ultrasound.
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The welding obtained using the punches 19 is very strong and the welding process is very rapid.
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In particular, the welding process carried out by hot elements, such as the punches 19, occurs along the edges of said through holes, creating welds B located therein in order to join the wrapper 2 and the bands 6, 7 of the label 8, 9 of the fruit and vegetable packaging 1. In this way, compared to the aforementioned welding technologies belonging to the prior art, a marked reduction is achieved in the surfaces affected by the fusion of the materials of the wrapper 2 and the label 8,9, in the cooling time and, finally, in productivity, with a greater number of packagings 1 produced per minute.
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An indirect effect to be included among the previous ones is, of course, the reduction in the unit cost of the single packaging 1.
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Similarly, said welding process using hot elements, such as punches 19, applied to the two versions of the present invention that involve the creation of a plurality of welding points 18 (see Figure 12) constituting the welding zones 21, 22, arranged respectively along rectangles and along a plurality of lines 23, proves to be particularly advantageous. Indeed, even in this case, localized welding areas are obtained between the wrapper 2 and the bands 6,7 of the label 8,9 of packaging 1, thus resulting in a marked reduction in the surfaces affected by the fusion of the materials of the wrapper 2 and label 8,9, the cooling time, and, ultimately, the unit cost of the single packaging for fruit and vegetables 1.
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Furthermore, with these last two versions, despite a longer execution time than with localized welding B at the edges of the holes, a welded joint with greater mechanical strength is obtained, capable of withstanding higher loads.
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Figure 9 illustrates, from a) to d), the main steps of the welding process on one end 4, 5 of the wrapper 2.
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Figure 9, step a) shows the cross-section of the end 4, 5 gathered into a cord; Figure 9, step b) shows the cross-section of the end 4, 5 gathered into a bead with the band 6, 7 partially wrapped around the end 4, 5; Figure 9, step c) shows the cross-section of the end 4, 5 gathered into a bead with the band 6, 7 completely wrapped around the end 4, 5, note that the end 4, 5 is slightly squashed while the band 6, 7 has its edges folded and pressed together, this positioning promotes the creation of a strong weld without the use of additional reinforcing elements; finally, in figure 9, step d), the welding process is illustrated using the punches 19 which pass through the end 4, 5 and the band 6, 7; in this case, there are three punches 19 and they create three welding points 18, but their number can be any starting from one, and the position of the welding points 18 can also vary, in relation to the resistance characteristics required by the packaging.
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As can be seen in Figure 9, in step d), the punch 19 has a pointed initial portion to facilitate penetration into the end 4, 5, which is gathered into a cord with the band 6, 7 wrapped around it, and a subsequent portion with a constant cross-section; Figure 10 illustrates examples of cross-sections of the punches 19: cylindrical, triangular, or square, as well as other different shapes.
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Figure 11 shows the band 6, 7, which shows the welding points 18 and a hot knife 20 that serves to refine the edge of the band 6, 7 while the welding points 18 are being performed and to provide greater strength to the welding point; in fact, the knife 20 creates an additional welding point.
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Figure 12 shows a band 6, 7 schematically that illustrates other variations of the present invention that involve different weld shapes.
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In the variant in the left of Figure 12, a number of welding zones 21 can be seen - in this example six zones 21 - of a substantially rectangular shape comprising a plurality of small-sized points 18; the welding zones 21 have a larger surface area than the single welding points 18 of the previous examples.
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In the variant on the right of Figure 12, a substantially rectangular welding zone 22 can be seen with a plurality of small points 18 arranged along a plurality of lines 23.
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In this version of the present invention, the welding points 18 do not pass through the band 6, 7 and the beaded end 4, 5, but are points in contact with the parts under compression.
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This configuration produces stronger welds that can be used for heavier packagings, this solution requires more time to complete but achieves stronger welding points.
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In any case, it should be noted that the wrapper 2 is closed using only the wrapper 2 itself and the label 8, 9, without any additional elements, thus eliminating the use of mechanical closing elements or reinforcements; it should also be noted that the wrapper 2 is closed by folding the bands 6, 7 longitudinally, making the closure very quick.
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With just these two components, it is possible to ensure adequate load capacity, durability, and the option of including a customized label.
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As already mentioned, the materials used to make the wrapper 2 and the label 8, 9 are always compatible with each other, making the packaging easily recyclable, compostable, or biodegradable.
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The present invention also relates to a packaging machine for producing the packaging 1 described above.
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Specifically, the packaging machine according to the present invention comprises a closing and welding unit 24 equipped with a closing and welding head 25 that creates the welds at the ends 4, 5 of the wrapper 2 of the packaging 1, and a printing and launching unit 26 for the labels 8, 9.
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The closing and welding unit 24, with the closing and welding head 25, and the printing and launching unit 26, can be applied to vertical, horizontal, and manual packaging machines.
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Furthermore, additional mechanical kits can be provided that allow the retroactive adaptation of the closing and welding unit 24 with the closing and welding head 25 and the printing and launching unit 26 to existing packaging machines, avoiding the replacement of still modern packaging machines and thus reducing costs and environmental impact.
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Figure 13 shows the assembly of the closing and welding unit 24 with the closing and welding head 25 and the printing and launching unit 26 applied to a vertical packaging machine.
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The printer and launcher unit 26 comprises a reel 27 with tape 28 containing the labels 8 and 9 die-cut from the tape 28 and prepared for packaging, a launcher unit 29 for the tape 28, and a variable data printing unit 30 for the labels 8 and 9.
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The reel 27 contains the flag-type or ribbon-type labels 8 or the continuous, or C2C, or clip-to-clip, labels 9, already pre-set with respect to their length, through the marking printed with black ink (Figure 8B) or with UV ink so as to provide a signal for dispensing along the length required for the label type and with the incisions or creases 14 and the pre-cuts or creases 15 correctly positioned and designed for the label type.
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It should be noted that the reel 27, comprising only a thin thermoplastic tape 28, can accommodate a considerable length of tape, allowing for high operating autonomy and increasing the operational efficiency of the packaging machine 1.
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The packaging machine 1 illustrated in the example in Figures 13 and 14 is of the vertical type and therefore also includes a conveyor belt assembly 31 on which the net casing 2 filled with fruit and vegetable products A (Figure 14) coming from inside the net-supporting tube (not shown) is deposited.
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The conveyor belt assembly 31 includes a small conveyor belt 32 made of elastic material that both cushions the fall of the fruit and vegetable products A coming from the net tube and allows the fruit and vegetable products A to be moved inside the wrapper 2 towards the closing area.
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Figure 14 shows the step of formation of the ends 4, 5 of the wrapper 2 collected in a cord, also corresponding to figure 9 in step a).
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This step is achieved by a linearly moving shutter device 33 which, when open, allows the passage of each wrapper 2 filled with fruit and vegetable products A from the net-supporting tube and, when closed, allows a net cord to be formed at the ends 4 and 5 of the wrapper 2. The linear shutter device 33 comprises a first pair of fixed abutment elements 34, shaped like a "V," arranged on the side of the printer and launcher unit 26, and a second pair of abutment elements 35, movable with the belt unit 31, also shaped like a "V" and arranged opposite to the "V" of the first pair of fixed abutment elements 34.
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The second pair of movable abutment elements 35 comprises two metal sheets 35a and 35b that are on slightly staggered planes, respectively at the top and bottom, with respect to the upper and lower planes of the fixed abutment elements 34.
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As mentioned, the second pair of abutment elements 35 is movable together with the conveyor belt assembly 31 and operates in contrast with the first pair of fixed abutment elements 34; the staggered planes on which the movable and fixed abutment elements operate and the opposing "V" shape of the two pairs of abutment elements allow for a progressive reduction in the passage width of the shutter device 33, so as to gather the ends 4, 5 of the wrapper 2 into a cord as illustrated in figure 9, step a).
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Furthermore, it can be noted, particularly from Figures 13-16, that the fixed abutment elements 34 include two grooves 36, slightly oblique and advanced with respect to the bottom of the "V" of the fixed abutment elements 34, which serve as a guide for the tape 28. As can be noted particularly from Figures 13, 14, the grooves 36 hold the edges of the tape 28 in an advanced position with respect to the bottom of the "V" of the fixed abutment elements 34 and therefore, when the gathered end 4, 5 advances towards the fixed abutment elements 34 moved by the movable abutment elements 35, the end 4, 5 itself also determines the folding of the band 6, 7 of the label 8, 9, as illustrated in Figure 9 step b), such folding being also facilitated by the pre-cuts or creases 15.
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The subsequent closing of the band 6, 7, illustrated in Figure 9, step c), occurs via a clamp device 37 that is part of the closing and welding head 25 and is illustrated in more detail in Figures 17, 18.
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The clamp device 37 comprises two arms 38, each equipped with a respective jaw 39 and a driving end 40 for actuation, and is operated via a double-acting actuator 41, for example, a double-acting pneumatic cylinder with a single rod, the cylinder 41 is fixed with its body to one driving end 40 and with its rod to the other driving end 40 of the arms 38.
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Figures 17, 18 show the position in which the cylinder 41 has its rod retracted and the jaws 39 are closed so as to grip the end 4, 5 gathered in a cord with the band 6, 7 completely wrapped around the end 4, 5 as illustrated in Figure 9 step c), in this closed position the two arms 38 are in contact with two respective limit switches 50, adjustable via a locking screw and locknut, in this way the space between the jaws 39 in the closed position can be adjusted in relation to the thicknesses of the ends 4, 5 gathered in a cord and of the bands 6, 7, to optimise the subsequent welding step.
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When the cylinder 41 has its stem extended, the jaws 39 are in the open position (not shown), allowing the insertion of the end 4, 5 gathered in a cord with the band 6, 7, as shown in Figure 9, step b); the insertion of the end 4, 5 gathered in a cord with the band 6, 7 into the open jaws 39 is caused by the movement of the second pair of movable abutment elements 35 which advances towards the first pair of fixed abutment elements 34.
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Each of the jaws 39 has a certain number of holes 42, in the example shown in the figures, four holes 42 for each jaw 39, which serve to pass the punches 19 which perform corresponding welding points 18, the cross-section of the holes 42 is corresponding to, and slightly larger than, that of the punches 19 so as to allow the punches to slide through the holes themselves; furthermore, the jaws 39 include a slot 43 for the passage of the hot knife 20 which finishes the edge of the band 6, 7 while the welding points 18 are performed.
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In Figure 18, the left jaw 39 is shown slightly detached from the arm 38 to which it is connected, to allow to observe that, on the internal face in contact with the band 6, 7, it includes ribs 44, for example, annular raised ribs concentric with the holes 42 or of another shape, these ribs 44 being intended to reinforce the weld of the ends 4, 5, by compressing the parts.
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It should also be noted that in the area of the end 4, 5 of the wrapper 2, the left jaw 39 is flat, while the right jaw 39 has a seat 39A (Figures 17, 18) to accommodate the aforementioned cord-shaped end 4, 5; however, the seat may also be located in the left jaw 39 and the right jaw 39 flat, or the seat may be located on both the right and left jaws; furthermore, the section of the seat 39A can be semicircular as illustrated in the figures or have a different section, for example it can be rectangular.
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The closing and welding head 25 also comprises driving means 45 for the punches 19 and the knife 20 comprising a slide 46 and an actuator 47, for example a double-acting pneumatic cylinder and cooling means 48 comprising nozzles 49 in a position substantially in line with the holes 42; the cooling means 48, through the nozzles 49, can send cooling air into the holes 42, so as to quickly cool the welds made by the punches 19.
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When the clamp device 37 closes the end 4, 5 gathered in a cord with the band 6, 7 of the packaging 1 being formed, a consent is sent to the driving means 45 for the punches 19 and the knife 20, which can move the latter through the holes 42 and the slot 43 through the jaws 39 so as to perform the welding and cutting of the ends 4, 5.
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In use, the wrapper 2 filled with fruit and vegetable products A coming from inside the net-supporting tube is deposited on the conveyor belt assembly 31, the wrapper 2 is translated from a previous packaging 1 during the closing and cutting step.
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The conveyor belt assembly 31 is moved by actuator means (not illustrated) together with the pair of movable abutment elements 35 towards the pair of fixed abutment elements 34, narrowing the passage space of the shutter device 33, so as to gather the ends 4, 5 of the wrapper 2 in a cord as illustrated in Figure 9 step a).
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In the printing and launching unit 26, the labels 8, 9 of the tape 28 are printed and are lowered into the grooves 36 of the fixed abutment elements 34.
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The gathered end 4, 5 advances towards the fixed abutment elements 34, moved by the movable abutment elements 35 inside the jaws 39, which are in the open position, allowing the gathered end 4, 5 to be inserted with the band 6, 7, as illustrated in Figure 9, step b); the end 4, 5 itself also determines the folding of the band 6, 7 of the label 8, 9, as illustrated in Figure 9 step b), this folding also being facilitated by the pre-cuts or creases 15.
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Therefore, the jaws 39 are closed so as to tighten the gathered end 4, 5 into a cord with the band 6, 7 completely wrapped around the end 4, 5 as illustrated in Figure 9 step c).
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The closing of the jaws 39 provides a consent for the driving means 45 of the punches 19 and the knife 20, which can move the latter through the holes 42 and the slot 43 through the jaws 39, so as to perform the welding and cutting of the ends 4, 5.
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The driving means 45 then retract the punches 19 and the knife 20 from the holes 42 and the slot 43, and the cooling means 48, through the nozzles 49, can send cooling air into the holes 42, so as to quickly cool the welds made by the punches 19.
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Following the cutting of the ends 4, 5, the upper closure of the wrapper 2 of a packaging 1 already filled and the lower closure of the wrapper 2 of a packaging being filled, are achieved.
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The shutter device 33 and the jaws 39 open, and the belt assembly 31 with the pair of movable abutment elements 35 returns to its initial position under the net-supporting tube; a new filling and closing cycle of packaging 1 can then proceed.
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Finally, Figure 19 shows an enlargement of the upper portion of Figure 2, which shows the version of the invention featuring circular holes made by punches 19, along the edges of which, the localized welds B, where the materials constituting the wrapper 2 and label 8 fuse, are schematically depicted.
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The invention, thus conceived, offers significant technical advantages.
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An important technical advantage is that the packaging 1 for fruit and vegetable products A allows for optimal use of its constituent materials, which are more resistant for containing the products, for example with a thermoplastic net, and are more easily recyclable and have a low environmental impact, and this is made possible by the fact that the label is made of the same material or a material compatible with that of the wrapper 2.
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Another advantageous technical aspect of the present invention concerns the creation of localized welds B along the edges of circular holes through hot punching to join the wrapper 2 to the bands 6, 7 of the label 8, 9 of the fruit and vegetable packaging 1.
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This feature, in fact, brings significant technical and economic advantages: a marked reduction in the surfaces affected by fusion, a shorter cooling time, and a consequent increase in productivity, as a greater number of packagings 1 are produced per minute.
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An additional, albeit indirect, advantageous effect to consider is the reduction in the unit cost of each individual packaging, while still achieving an optimal quality solution.
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Furthermore, the aforementioned reduction in weld surfaces, limited to specific areas, allows for a significant saving in plastic material, particularly that of the label, while also considering environmental considerations.
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The same considerations can also be extended to alternative versions of the present invention, i.e. those that provide for the creation of welding points 18, arranged along rectangular surfaces or along a plurality of lines 23, obtained by compressing the parts, i.e. the wrapper 2 and the bands 6,7 of the label 8,9. In fact, although in the latter two cases we are dealing with larger welding surfaces, characterized by a longer execution time compared to the case with localized welding B at the edges of the holes, in favor of a greater mechanical resistance of the welded joints, it can certainly be stated that the same advantages described above remain compared to the other solutions already mentioned belonging to the prior art, in terms of reduction of the surfaces affected by the fusion, shorter cooling time, and consequent increase in productivity, understood as the number of packagings 1 produced per minute.
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We have thus seen how the invention achieves the proposed purposes.
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The present invention has been described according to preferred embodiments, but equivalent variants may be conceived without departing from the scope of protection offered by the following claims.