Machine and method for packaging articles in wrappers

Abstract

A packing machine (M) and method for wrapping a sheet (P), in particular shock-absorbing paper, around an article (A) to form a bag (B), comprising means (4, 5) for folding the sheet around the article, means (6) for adhering the sheet to itself to form a sheet tube (TB) around the article (A), and compression and cutting means (7) for sealing and separating portions of the tube by sealing and separating the upstream and downstream ends of the article, acting on the sheet in a cutting zone located upstream of the sheet folding and adhering means in cooperation with a second adhesive application means (10).

Description

Technical Field

[0001] The present invention relates to a machine for packaging articles by winding. In particular, the present invention relates to a sheet of paper material, particularly a multi-sheet, and particularly formed from at least one layer of wrapping paper and one layer of embossed paper, the layers being adhered to the previous layer to form a sheet capable of absorbing shocks, and relates to a machine suitable for winding a sheet that is wound around an article to form a closed bag for containing individual articles.

Background Art

[0002] Machines for winding a film around an article to form a closed bag made of a heat-sealable plastic material are generally known. Since the film used for packaging is usually cellophane, these are generally called "cellophane wrapping machines". Cellophane wrapping machines are generally known for packaging individual articles, but they have to be stopped and reassembled if it is desired to perform a type change, particularly because the sizes of the articles to be packaged are different. Italian Patent Application No. 102018000011148 (not yet published at the time of filing of the present application) describes a bagging machine designed to overcome this problem by enabling the bagging of articles of different sizes continuously supplied along the same line. The material can be any heat-sealable film containing a shock-absorbing film, such as a packaging material generally known as "air bubble cushioning material", inside.

[0003] However, for various reasons, particularly environmental and economic reasons, it is desirable to use different types of materials instead of the plastic materials used in the aforementioned machines. In fact, the preference for paper materials such as cardboard and paper for packaging and bagging has increased (particularly after the introduction of certain legal regulations). These can also be used as shock-absorbing materials, not only having a lower impact on the environment, but also being lighter, colorable, and directly printable.

Prior Art Documents

[0004] [Patent Document 1] Italian Patent Application No. 102018000011148 Specification [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Therefore, it is desirable to use paper materials to bag items containing different types of goods in the same machine and operation cycle, without having to stop the machine to accommodate different items, and rather while feeding these items into the machine despite their different types and sizes. [Means for solving the problem]

[0006] These drawbacks are overcome hereby by the packaging machine described in claim 1 of this specification and the method described in claim 15 of this specification.

[0007] Further preferred features of the packaging machine according to the present invention are described in the dependent claims.

[0008] Here, with reference to the attached drawings, one preferred embodiment of the present invention will be described as an example. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic perspective view of the machine according to the present invention. [Figure 2] This is a schematic diagram of the steps, as performed by the machine in Figure 1, which include wrapping a paper sheet around an article to form a bag for containing the individual article. [Figure 3] This is a schematic enlargement of the details shown in box K of Figure 1. [Figure 4] Figure 1 is a schematic perspective view of a specific key component of the machine. [Figure 5] This is a schematic perspective view of the machine details in the area where the initial step of wrapping a sheet around a moving object is performed. [Figure 6] This is a schematic diagram of a first means for applying adhesive along the side flap. [Figure 7] This is a partial schematic perspective view of other specific components of the machine. [Figure 8] This is a partial schematic perspective view of a further part of the machine. [Figure 9] This is a partial schematic perspective view of a second means for applying adhesive to a sheet. [Figure 10] This is a partial schematic perspective view of a compression and cutting means for closing and cutting a sheet that has been wrapped in a tubular shape around an article to form a bag. [Modes for carrying out the invention]

[0010] Referring to the attached drawings, particularly Figure 1, M represents a packaging machine suitable, in its entirety, for wrapping a sheet P around an article A to form a bag B for containing individual articles, according to the present invention.

[0011] The machine M comprises a conveying means 1 suitable for receiving article A (which must be packaged) and conveying it in the conveying direction indicated by arrow D, a vacuum conveyor belt 2 arranged continuously with respect to the conveying means 1, and a sheet P feeding station 3, for example, a reel 30 on which the sheet P is wound in the form of a web, and a feeding station 3 for feeding the sheet P between the conveying means 1 and the conveyor belt 2 in a direction laterally to the conveying direction D of article A, with the central portion PC (as shown in Figure 2) resting on the conveyor belt 2, and the lateral portions PL1 and PL2 positioned on two opposing sides of the central portion PC so as to protrude laterally from the conveyor belt 2, for conveying the sheet P. The system includes a sheet P feeding station 3, which is equipped with a feeding / returning means 31, so that an article A transported by the conveying means 1 is positioned above the central portion of a sheet P placed on the conveyor belt 2, and the sheet P on which the article A is positioned can be held by suction of the vacuum conveyor belt 2 and fed in the direction of travel indicated by arrow E in Figure 2, which may be the same direction as indicated by arrow D in Figure 1, and a folding means 4 (better shown in Figure 3) positioned and configured relative to the conveyor belt 2 so that the sheet P can be folded in contact with the lateral portions PL1 and PL2 of the sheet P that protrude laterally from the conveyor belt 2.

[0012] According to a preferred embodiment of the present invention, and particularly with reference to Figures 3 and 5, the machine M comprises a structure 5 associated with a conveyor belt 2 and shaped to define a tunnel T for articles A transported by the conveyor belt 2 to pass over the central portion PC of a sheet P, and a folding means 4 shaped and configured to contact the lateral portions PL1, PL2 of the sheet P that protrude laterally from the conveyor belt 2 during sheet feeding, and folds the lateral portions PL1, PL2 of the sheet P around the tunnel-shaped structure 5 such that the two side flaps L1, L2 of the sheet P overlap and form a sheet tube TB that is wrapped around the tunnel-shaped structure 5.

[0013] In particular, the structure 5, which is shaped like a tunnel T, is constructed such that the tunnel T defines a passage for articles A, and the height of the structure relative to the conveyor belt 2 is such that articles A of different sizes and heights, such as individual magazines, stacks of magazines, boxes containing products, etc., can be transported within the tunnel.

[0014] Furthermore, the folding means 4 is configured to contact the lateral portions PL1 and PL2 of the sheet protruding from the side of the conveyor belt 2 with respect to the conveyor belt 2 and the structure 5 formed like a tunnel T, and to fold the lateral portions around the wall of the tunnel T to form a sheet tube TB that accommodates articles of different sizes and heights. In this way, a single structure and a single machine M configuration make it possible to wrap a sheet around articles of different sizes and heights moving along the conveyor belt.

[0015] Furthermore, the machine M includes a first adhesive application means 6 (Figure 6) positioned above the structure 5 formed like a tunnel T and configured to apply adhesive to one of the two edges L2 of the sheet P (consisting of lateral portions PL1 and PL2) before it is superimposed on the tunnel structure, and a compression and cutting means 7 (Figure 10) positioned downstream of the structure 5 formed like a tunnel T at a break in the conveyor belt 2 and operated to clamp the sheet tube TB first forward relative to the position of the article A inside the sheet tube TB, and then backward (in front of the subsequent article), thereby bonding and cutting the sheet P and obtaining a bag B that will contain the article inside. According to a preferred embodiment of the present invention, these means for compressing and cutting the sheet can be accompanied by the article A during the compression and cutting steps (enabling continuous feeding of the sheet and article), and can also be transported in the direction of sheet travel E and the opposite direction so that they can return to their initial position when not engaged with the sheet and restart the cycle with the next article. For example, the compression and cutting means 7, which is known in itself, can be mounted on a movable lower carriage 70. The means may be a clamp of appropriate shape as shown in Figure 10, which can be lowered onto the conveyor belt 2 at the end of the bag being formed and may be equipped with a central blade. In a preferred embodiment, in relation to the compression / cutting means 7, a discharge means 71 for removing air from the bag being formed is envisioned. Their action reduces the air content in the bag before the bag is completely sealed and separated from the tube TB. In one embodiment, the means consists of a press 71 of appropriate size located downstream of the compression / cutting means 7. Before the action of the cutting means to seal the second end of the bag, the press is lowered and the bag being formed (as shown in Figure 9, the first end is already sealed; this is the state immediately before the action of the air discharge means) is compressed with appropriate pressure relative to the article so as to recirculate air toward the sheet tube TB, thereby reducing the air content of the bag being formed. Immediately thereafter, the compression / cutting means 7 is activated and the bag is sealed and separated with an air content such that there is no risk of the bag bursting or increasing in volume.The pressure applied by the press can be adjusted by pre - determining the stroke or pressure applied to the bag in a generally known manner (using sensors or other means) so as to let air escape without damaging the article or the packaging sheet. Advantageously, the discharging means can be attached to the same lower carriage 71 as the compressing and cutting means 7. Other systems may be provided. The air discharge achieved in this way before sealing is particularly advantageous with respect to generally known systems such as those involving the perforation of bags generally carried out by plastic bags. In fact, the perforation of paper materials as used by the machine according to the invention can be adopted if considered appropriate, but tends to weaken the bag and make it prone to tearing. However, in this way, it becomes possible to use different materials such as paper materials.

[0016] In order to seal the ends of the bag by compression, some adhesive needs to be applied to the sheet P inside the already formed tube TB. In particular, for sealing the ends of the two bags separated during cutting, the adhesive must be placed between one article and the next. For this purpose, a second adhesive - applying means suitable for applying the adhesive to the surface of the sheet P facing the article and forming the inner surface of the tube TB is envisaged. Preferably, the said means apply the adhesive before the tube is formed, more preferably before the sheet is fed to the conveyor belt 2. The adhesive is applied in relation to the position and size of the article, which are appropriately measured, so that the articles are properly deposited on the sheet between one adhesive - application point and the next by the conveyor.

[0017] Referring to FIG. 9, the second adhesive application means 10 comprises a spraying device 11 suitable for spraying an adhesive onto the surface of the sheet inside the formed tube, as described above. The second means can be advantageously positioned at the end of the feeding / returning means 31. They are preferably designed to spray one or preferably two adhesive strips transversely to the sheet travel direction, preferably in the central portion PC of the sheet. For example, the spraying device 11 may be supplied with adhesive from a tube 12 and is characterized by a series of spraying nozzles suitably oriented towards the sheet P so as to spray the adhesive all at once along the entire area of the associated sheet P, allowing the sheet P to continue to move during the adhesive application step.

[0018] Thus, the machine can wind the sheet around articles of different sizes and heights and obtain a bag for containing the individual articles therein without having to stop the machine and remove and refit components.

[0019] Referring to FIGS. 4 and 5, according to a preferred embodiment, a structure 5 shaped like a tunnel T comprises side walls 51, 52 arranged along the sides of the conveyor belt 2 and at least one upper wall 53, 54 between the side walls 51, 52. On the other hand, the folding means 4 is configured to fold the lateral portions PL1, PL2 of the sheet P around the side walls 51, 52 and the upper walls 53, 54 of the structure 5 shaped like a tunnel T so that the two side edges L1, L2 of the sheet P overlap and form a sheet tube TB wound around the side walls and the upper wall of the structure 5 shaped like a tunnel T. Referring to FIGS. 7 and 8, advantageously, the side walls 51, 52 of the structure 5 shaped like a tunnel T may be made to include fixed lower parts 510, 511 and movable upper parts 520, 521 attached so as to be able to move above the lower parts 510, 511 and supporting the upper walls 53, 54.

[0020] In this way, the position of the upper parts 520, 521 of the side walls 51, 52 relative to the lower parts 510, 511 can be adjusted and changed to alter the distance between the upper walls 53, 54 and the conveyor belt 2, and thus the height of the tunnel T can be changed according to the different actual heights of the articles to which the sheet must be wrapped.

[0021] Referring particularly to Figures 7 and 8, another preferred embodiment of the machine M according to the present invention lies in the fact that it comprises means 9 for creating an air cushion between a sheet tube TB and a structure 5 formed like a tunnel T. This convenient means prevents sliding, and therefore friction, between the sheet P (and in particular the tube TB formed therefrom) and the walls of the structure 5 formed like a tunnel T. According to the particular embodiment shown in the figures, the means 9 for creating an air cushion may comprise a duct 91 connected to a source of compressed air and having a series of holes 92 for the passage of air. The duct 91 is arranged to guide the jet of air coming out of the holes 92 toward the portion of the sheet P folded relative to the structure 5 formed like a tunnel T. For example, these ducts 91 can be arranged along at least portions of two side walls 51, 52 of the structure 5 formed like a tunnel T.

[0022] Furthermore, the means 9 for creating an air cushion may also include a suction belt 93 wound in a closed loop and positioned above a structure 5 formed like a tunnel T, which holds a portion of the folded sheet P on top of the structure 5 formed like a tunnel T by suction, and the belt is used to guide the sheet P in synchronization with the progress of the conveyor belt 2. In a further advantageous embodiment, the machine M may include an optical detection means 96 positioned along the structure T to detect the passage of articles A into the tunnel T and to detect the distance between articles A, and the heat sealing and cutting means 7 may remain inoperable if the optical detection means 96 detects that the distance between two consecutive articles is less than a minimum preset distance. This prevents damage to articles that are too close to each other and leaves insufficient space for the operation of the compression and cutting means 7.

[0023] Referring particularly to Figure 6, according to a preferred embodiment, the first adhesive application means 6 comprises at least one adhesive dispenser 61, fixed contact elements 62, 63 positioned downstream of the dispenser 61 with respect to the direction of travel E of the sheet P to contact the overlapping edges L1, L2 of the sheet P at the top and to facilitate adhesion, and at least one movable contact element 64 that can be activated when the conveyor belt 2 is stopped, thereby positioning the conveyor belt 2 over the two overlapping edges L1, L2 of the sheet P, keeping them overlapped and thus keeping the tube TB sealed.

[0024] Therefore, the machine M is equipped with a suction element positioned below the conveyor belt 2, and as a result, the conveyor belt 2 holds the central portion PC of the sheet P positioned on it by suction while the sheet P moves in the direction of travel E.

[0025] As shown in Figure 1, an article loading station 8 may be envisioned, which is located at the first part of the transport means 1 and includes an identification means 81 configured to detect and identify an identification code assigned to article A.

[0026] Finally, according to a more preferred embodiment of the present invention, the machine M may include a detection means 82 positioned along the conveying means 1 and configured to measure the height of the article A, and the conveying means 1 may be configured to stop when the detection means 82 detects the passage of an article that is higher than the tunnel T. Printing means may be provided, if desired, particularly for the sides of the sheet which will be the outer parts of the tube and bag. These printing means may be positioned in the feeding and returning means 31. Downstream of the compression shearing means, if desired, further processing components may be positioned, such as a labeler which can print a label according to data read from an identification code.

[0027] In the machine M according to the present invention, the presence of a tunnel-shaped structure also makes it possible to use an impact-absorbing packaging sheet. In a preferred embodiment, the sheet is formed from at least two layers of paper, one of which is smooth and the other is embossed (to feature a textured surface) and bonded to the first layer (to form an impact-absorbing structure). Preferably, if there are only two layers as described above, the embossed layer faces the inside of the tube and is in contact with the article being packaged. Other layers may also be featured, for example, an embossed layer may be sandwiched between two smooth layers. The embossing may feature recesses having a circular base with a spacing in between of 0.3 to 10 mm, for example, 0.5 mm. This type of impact-absorbing sheet is known, and different types are commonly manufactured, for example, featuring different numbers of layers and different sizes of embossing, and are commonly used to wrap an object being packaged to protect its surface as a vibration-damping pad. Those skilled in the art can select the type that best suits different needs such as flexibility, lightweight design, affordability, and protection requirements.

Claims

1. A packaging machine (M) designed to wrap a sheet of paper (P) around an article (A) to form a bag (B) containing the individual article, a conveying means (1) configured to receive an article (A) to be packaged by the sheet and convey it in a conveying direction (D); a vacuum conveyor belt (2) arranged in series with the conveying means (1); a sheet (P) feeding station (3) for feeding the sheet (P) transversely to the conveying direction (D) of the articles (A) between a reel (30) on which the sheet (P) is wound or a similar sheet securing means, the conveying means (1) and the vacuum conveyor belt (2), with a central portion (PC) of the sheet (P) placed on the vacuum conveyor belt (2) and side portions (PL1, PL2) protruding laterally from the vacuum conveyor belt (2) and positioned at the sides of the central portion (PC); a sheet (P) feeding station (3) including a feeding and returning means (31) for arranging the sheet (P) in a state where the article (A) conveyed by the conveying means (1) is arranged above the central portion (PC) of the sheet (P) placed on the vacuum conveyor belt (2), and the sheet (P) with the article (A) arranged on the central portion (PC) can be held by suction by the vacuum conveyor belt (2) and can be fed in the traveling direction (E); folding means (4) arranged and configured relative to the vacuum conveyor belt (2) so as to be able to fold against the side portions (PL1, PL2) of the sheet (P) that protrude laterally from the vacuum conveyor belt (2); a structure (5) associated with the vacuum conveyor belt (2) and shaped to define a tunnel (T) through which the articles (A) conveyed by the vacuum conveyor belt (2) pass above the central portion (PC) of the sheet (P), wherein the folding means (4) is shaped and configured to contact the side portions (PL1, PL2) of the sheet (P) protruding laterally from the vacuum conveyor belt (2) during feeding of the sheet, and folds the side portions (PL1, PL2) of the sheet (P) around the structure (5) shaped like the tunnel (T) so that two side flaps (L1, L2) of the sheet (P) overlap and form a sheet tube (TB) that is wrapped around the structure (5) shaped like the tunnel (T); a first adhesive application means (6) positioned above the tunnel-shaped structure (5) and configured to apply adhesive to one of the two side flaps (L1, L2) of the sheets (P) before overlapping; a compressing and cutting means (7) positioned downstream of the tunnel-shaped structure (5) at the gap in the vacuum conveyor belt (2), which is actuated to clamp the seat tube (TB) first in front and then behind the position of the article (A) inside the seat tube (TB), thereby sealing and cutting the sheet (P) to obtain a bag (8) containing the article therein; a second adhesive application means (10) designed to apply adhesive to the side of the seat that will become the inner surface of the seat tube (TB); Equipped with the first adhesive application means (6) comprises at least one adhesive dispenser (61), fixed abutment elements (62, 63) arranged downstream of the adhesive dispenser (61) with respect to the direction of travel (E) of the sheet (P) in order to contact the two overlapping side flaps (L1, L2) of the sheet (P) and facilitate bonding of the two side flaps, and at least one movable abutment element (64) that can be actuated when the vacuum conveyor belt (2) stops, the at least one movable abutment element (64) being positioned above the two overlapping side flaps (L1, L2) of the sheet (P) to keep the two side flaps overlapped and to keep the seat tube (TB) sealed; Packaging machine (M).

2. 2. The machine (M) according to claim 1, wherein the tunnel-shaped structure (5) comprises side walls (51, 52) arranged along the sides of the vacuum conveyor belt (2) and at least one top wall (53, 54) between the side walls (51, 52), and the folding means (4) is configured to fold the lateral portions (PL1, PL2) of the sheet (P) around the side walls (51, 52) and the top wall (53, 54) of the tunnel-shaped structure (5) so that two lateral edges (L1, L2) of the sheet (P) overlap and form the seat tube (TB) wrapped around the tunnel-shaped structure (5).

3. 3. The machine (M) according to claim 2, wherein the side walls (51, 52) of the structure (5) shaped like the tunnel (T) comprise a fixed lower part (510, 511) and a movable upper part (520, 521), the movable upper part (520, 521) being attached to the fixed lower part (510, 511) with the possibility of movement and carrying at least one upper wall (53, 54), the position of the movable upper part (520, 521) relative to the fixed lower part (510, 511) being adjustable and changeable so as to change the distance of the upper wall (53, 54) from the vacuum conveyor belt (2) and thus the height of the tunnel (T).

4. A machine (M) according to any one of claims 1 to 3, comprising means (9) for creating an air cushion between said seat tube (TB) and said tunnel-shaped structure (5).

5. 5. A machine (M) according to claim 4, wherein the means (9) for creating the air cushion comprise a duct (91) connected to a source of compressed air and provided with a series of holes (92) for the passage of air, the duct (91) being arranged to direct the jets of air emerging from the holes (92) towards the part of the sheet (P) folded against the structure (5) shaped like the tunnel (T).

6. 6. Machine (M) according to claim 4 or 5, wherein the means (9) for creating the air cushions comprises a suction belt (93) wound in a closed loop and arranged above the tunnel-shaped structure (5) to hold by suction the portion of the sheet (P) folded onto the tunnel-shaped structure (5), the suction belt (93) being used to guide the sheet (P) in synchronism with the advancement of the vacuum conveyor belt (2).

7. 7. The machine (M) according to any one of claims 1 to 6, comprising optical detection means (96) arranged along the structure (5) shaped like the tunnel (T) and configured to detect the passage of the articles (A) in the tunnel (T) and to detect the distance between the articles (A), wherein the heat sealing and cutting means (7) are configured to remain inoperable if the optical detection means (96) detects that the distance between two consecutive articles is less than a minimum preset distance.

8. 8. The machine (M) according to any one of claims 1 to 7, comprising a suction element arranged below the vacuum conveyor belt (2), which holds by suction the central portion (PC) of the sheet (P) positioned on the vacuum conveyor belt (2) while the sheet (P) moves in the forward direction (E).

9. A machine (M) according to any one of claims 1 to 8, comprising an article loading station (8) positioned at the beginning of the conveying means (1) and equipped with an identification means (81) configured to detect and read an identification code given to the article (A).

10. A machine (M) according to any one of claims 1 to 9, comprising detection means (82) arranged along the conveying means (1) and configured to measure the height of the article (A), the conveying means (1) being configured to stop when the detection means (82) detects the passage of an article that is higher than the tunnel (T).

11. A machine according to any one of the preceding claims, wherein the second adhesive application means is capable of applying adhesive in strips transverse to the direction of travel of the sheet.

12. A machine according to any one of the preceding claims, wherein the second adhesive application means is positioned in the feeding and returning means (31) upstream of the feeding point of the sheet onto the vacuum conveyor belt (2).

13. 6. A machine according to claim 5, comprising means (72) for evacuating the air from the bag being formed, said means (72) being designed to act in cooperation with said compressing and cutting means (7) and to compress the seat tube (TB) against the article before sealing and separating the bag from the seat tube.

14. 14. A packaging method, in which an article to be packaged is wrapped in a sheet comprising at least two layers of paper by a machine according to any one of claims 1 to 13, one layer of said paper being a smooth layer and one layer being embossed and glued onto said smooth layer.

15. The method of claim 14, wherein the smooth layer is the outer surface of the seat tube and the outer surface of the formed bladder.

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