ES2292007T3 - MACHINE TO MAKE TUBULAR BAGS FOR THE FORMATION OF BAGS WITH SIDE EDGES OF CONFORMATION. - Google Patents

Abstract

A vertical bagging machine for the formation of bags in plastic film comprising a pipe with a substantially circular or oval cross-section (12) for delivering product around which is formed and guided from top to bottom a pipe of plastic film and transverse sealing means (27) of the pipe of film arranged downstream of the bottom end of the delivery pipe to form a sequence of closed bags containing the delivered product, characterised in that along the delivery pipe (12) there is means for the formation of longitudinal folds along a pipe of film and sealing means of said folds, guide means (16) being arranged at the bottom end of the delivery pipe to give the pipe of film a rectangular section with said folds at the corners of the rectangular section. <IMAGE>

Description

Machine for making tubular bags for formation of bags with lateral edges of conformation.

The present invention relates to a machine vertical for bagging, suitable for packaging bags with reinforcement forms on the side edges and a bottom square (usually also called bags "Stabilo").

Bagging machines are known verticals provided with a supply tube positioned vertically or with a selected inclination in which it is formed a tube with a plastic film that is guided from the part top to bottom from a film reel keep going. Downstream of the lower end of the tube supply (from which a quantity of product to be formed is packed at each stage of advance of the film tube) are provided with transverse sealing and cutting means (which can understand configuration means, for example one way square, to the bottom of the bag) fit to form a sequence of bags containing the product supplied. The pipes supply of these machines usually have a section circular (or at least oval) and are suitable for packaging high speed and with very little chance of getting stuck. Examples of such developments are described in the US Patent Nos. 5,505,040 and US 4,079,662 disclosing the manufacture of bags from a supply tube circular, in which longitudinal folds are formed in the film to facilitate the manufacture of a flat bottom and rectangular, characterized in that it consists of some folds upper and lower triangular. However, the machines known verticals are not suitable for making bags that have a parallelepiped shape, such as the so-called bags "Stabilo."

"Stabilo" bags are bags that they have four closed vertical folds that form four side edges; the existence of the edges provides the bag a shape similar to that of a parallelepiped that makes it fit to stand on its own supported on the base rectangular.

To pack "Stabilo bags" have developed vertical machines (such as the one disclosed  by US Patent No. 6,513,308) comprising a tube supply that has a rectangular section to facilitate the formation of the lateral edges and provide a shape suitable for the film tube at the time of sealing the bag transversely. On the outer surface of the supply tube Guiding fins are positioned to form four longitudinal folds in the film tube, which then they are pinched and closed to form lateral edges with shape.

However, these types of machines suffer from a number of important drawbacks, particularly when the Product to be packaged has a shape or is of a type that tends to get stuck in the tube, due to the reduced "space" of passage in the tube, or when a high bagging speed and a high productivity The square shape of the cross section of the supply tube (which has the same perimeter as the film) does not allow to increase the area for the flow supply of product, so that the bagging process is little Reliable and usually the speed cannot be reduced. In fact, Due to the shape of the tube, bagging machines "Stabilo" frequently suffer from binding problems, which make frequent operator interventions necessary that therefore reduce the productivity of the device.

The main objective of the present invention is to overcome the inconveniences cited above by providing a machine for bagging bags "Stabilo" suitable for bagging high speed and reach a productivity rate satisfactory

Another objective of the present invention is manufacture a reliable packaging machine that has a structure Simple and economical

In view of this objective, it was decided to create according to the invention, a bagging machine to form bags in a plastic film according to claim 1.

These objectives are achieved, according to the invention, with a vertical bagging machine to form bags  from a plastic film according to claim 1.

In order to clearly expose the principles innovators of the present invention and its advantages in relation to to the state of the art, a possible embodiment in which these principles apply to example title in relation to the attached drawings, in the that:

- Figure 1 is a perspective view of a bagging machine designed according to the principles of present invention,

- Figure 2 is another perspective view of the bagging machine of figure 1 in which they have been removed some elements,

- Figure 3 is a detail of the machine for bagging of the previous figures,

- Figure 4 is a view of a bag manufactured with a machine according to the invention,

- Figure 5 is a sectional view of a tube of film inside the machine precisely at the moment before the transverse sealing stage, and

- Figure 6 is a view of a section of the tube of film at the time of supplying the product to be packaged.

Referring to the Figures, Figure 1 represents a vertical bagging machine 11 for manufacturing  of bags formed with four closed side folds that they form lateral stabilization edges; these bags, a example of which is represented for example in Figure 4, are known in the field of bags as "Stabilo" bags.

These bagging machines 11 comprise a supply tube 12 (which may be positioned in position vertical or in a selected inclined position) around the which a continuous tube of a plastic film is guided from the top to the bottom. The film tube is formed around the supply tube 12 by means 14 suitable from a continuous film coil that supplies  to the machine (not shown in Figure). The means 14 comprise a guide profile positioned near the end top of supply tube 12 and is manufactured according to Known techniques in the field of bagging with machines vertical whose means, therefore, will no longer be described in detail.

Supply tube 12 has an opening upper upstream of which they are positioned so known means to dose the product to be packaged (no represented in the Figure). The film tube that forms around supply tube 12 moves from the top to the bottom, dragged by known mobile means (not represented). The drag is designed, so that it is suitable for seal a bag at each stage of advance of the film tube towards the bottom.

The tube 12 is mounted in a structure of support 13 on which the means 14 for wrap the film around the supply tube 12.

Figure 2 shows a machine bagging according to the invention with some elements removed. In the which, at the height of profile 14 to wrap the film band, folding means 29, 30 and 31, which have the function of forming two longitudinal folds project outward from the tube of film wrapped around the supply tube 12.

In Figure 3, in which the winding profile 14, the folding means are more visible. The two vertical ribs 31 are mounted on the supply tube 12 and are designed to remain inside the tube film (not shown) during machine operation. The two fins 30, on the other hand, are mounted on the structure of support 13, like the guiding element 29. The body of guided 29 is mounted between the two ribs 31, so that the fins 30 are positioned next to the ribs 31, parallel to them. During bagging, fins 30 and guiding body 29 remain outside the film tube and together with the ribs 31 define two small suitable spaces to form two folds that project outward from the tube of movie. On the opposite side of the supply tube are positioned very similar folding means 60, 61, which form two folds in mirror with respect to the two folds formed by the means 29, 30 and 31. When it has already gone through the elements of folded, the film tube has a cross section similar to that shown in Figure 6, with the folds 51 projecting parallel to each other outside the tube film that presents a circular section. Note, the fact that the ribs 31, in the embodiment of the invention project parallel to each other from the supply tube.

Immediately downstream of the means of folded sealing means are suitable for clamping and seal the previously formed folds. To each folding unit a sealing unit corresponds. At the bottom of the bending unit 29, 30 and 31 a sealing unit is positioned 41, which is suitable for sealing the two folds formed by the corresponding folding means. The sealing unit 41 is supported by the lever 20 mounted on the support structure 13 and It is formed by a pair of vertical sealing sheets 22, hydraulically or pneumatically moved by means of known drive 25. The two sheets 22 are suitable for seal in the direction of the contrast body 23 to clamp the longitudinal folds formed upstream by the corresponding folding means at each stage of advance of the film towards the bottom, sheets 22 and the body of contrast 23 are arranged vertically and have a shape elongated, particularly, its length must be at least the same than the height of the bag, to ensure the formation of the edges sides along the entire length of the film tube.

On the diametrically opposite side of the tube supply 12 is positioned a second sealing unit 42, identical to the sealing unit 41 and suitable for operation with the folds formed by the folding means 60, 61.

According to known techniques in the field of vertical bagging, the machine can also include other longitudinal sealing means, suitable for sealing longitudinally the film tube wrapped around the tube Supply 12. However, normally the longitudinal seal of the tube is made in one of the four welds of the folds 51, avoiding another fifth weld on the tube movie.

At the bottom of the supply tube 12 a supply hole 15 is positioned from which the product to be packaged (see Figure 1). Supply tube 12 presents a cross section with an approximately circular shape at along its entire length until it reaches the supply hole 15. The tube section may be oval or have a similar shape. (without sharp corners). This solution allows to have the maximum area for the flow of product to be supplied for the same perimeter of cross section of the film tube. That way It is possible to minimize product delivery time, accelerating the entire bagging procedure.

Downstream of supply hole 15 means 16 are positioned to form a section transverse of the approximately rectangular film tube. The means 16 comprise a pair of guides 16 that push the walls of the film from inside the tube, which modify progressively the rectangular cross section passing from a cross section of circular shape to one of rectangular shape. The two guides 16 project from the hole 15 towards the part lower and have an angular position with respect to the means of folded so that the closed longitudinal folds are positioned at the top of the rectangular section of the film tube Figure 5 represents the section that the tube of film adopts downstream of guides 16, with folds closed 51 at the top of the rectangle described by the tube. Note that advantageously, the final part of the guides (or walls) 16 define the smaller side of the rectangle that forms the rectangular cross section of the film tube. This solution It is suitable to prevent walls 16 from interfering in any way with the supply flow, since they widen slightly outward as they move away from the axis of the tube supply.

At a lower height in relation to the guides 16 known transverse sealing means are positioned 27 (schematically represented in Figure 1), preferably equipped with known means to configure (preferably a square shape) the bottom of the bag. At each stage of advance of the film tube, the sealing means transverse 27 close the bags transversely forming a sequence of bags from a continuous film tube. He closed is done parallel to the two walls of the tube film, so that a bag is formed that has a shape similar to that of a parallelepiped.

According to known techniques, together with the transverse sealing means 27 may be mounted about elements for cutting the newly formed bag from the tube movie.

So, it is clear that they have achieved the objectives proposed in the present invention. Particularly, a bagging machine to form type bags "Stabilo" suitable for operation at a high speed of packaging and achieve high productivity. In fact, the section Circular supply tube is suitable to reduce the time of product supply in a bag of the same dimensions, of so that the total time of the bagging process is accelerated. It has also been verified that in the machine according to this invention reduces the frequency of jams and blockages, which contributes to a greater increase in the productivity of the machine.

Obviously, the previous exposition of a embodiment in which the innovative principles are applied  of the present invention is provided solely by way of example of such innovative principles and therefore should not be considered as limiting the scope of the same claimed By civil laws.

Claims (7)

1. Vertical bagging machine intended to form bags from a plastic film comprising a tube (12) having a substantially circular or oval section of product supply around which it is formed and guided from the top to the lower part is a plastic film tube, guiding means (16) arranged at the lower end of the supply tube (12) to provide the plastic film with a rectangular section and transverse sealing means (27) by the plastic film tube disposed downstream of the lower end of the supply tube (12) to form a sequence of closed bags containing the supplied product, characterized in that along the supply tube (12) with substantially oval section means or circular they are present to form sealed longitudinal folds along the plastic film tube, said means being made God to form the longitudinal sealed folds by folding units (29, 30, 31, 60, 61) to longitudinally fold the plastic film, followed by sealing units (40, 41) to seal the longitudinal folds (51) formed in the plastic film tube by the folding units (29, 30, 31, 60, 61), guiding means (16) at the lower end of the supply tube (12) having a lower end defining said rectangular section whose corners are arranged in correspondence with the longitudinal seals formed in the plastic film tube by the sealing units (40, 41). 2. Bagging machine according to claim 1, characterized in that said means for providing the film tube with a rectangular shape comprise a pair of guides (16) extending opposite the lower end (15) of the downward supply tube. 3. Bagging machine according to claim 2, characterized in that each guide (16) comprises a wall, the lower end of which defines a short side of the rectangle described from the section of the film tube until the time of transverse sealing. 4. Bagging machine according to claim 1, characterized in that said folding means comprise two folding units, each comprising a pair of longitudinal ribs (31) fixed in the supply tube (12), a guiding body ( 29) mounted between the two guides (31) and a pair of longitudinal fins (30) arranged laterally with respect to the ribs (31), said guiding means and said fins being mounted on a support structure and defining with the ribs (31 ) a reduced space crossed by the wall of the film tube to form a pair of raised folds. 5. Bagging machine according to claim 4, characterized in that the two folding units are arranged diametrically opposite to the supply tube (12). 6. Bagging machine according to claim 4, characterized in that said means for sealing the folds are formed by two sealing units (40, 41), each comprising a contrast body (23) arranged in the lower part of the body of guidance (29) of the folding unit and a pair of vertical sealing sheets (22) arranged on opposite sides of the contrast body (22) that are suitable for clamping the preformed fold in cooperation with the vertical side of the contrast body (2. 3). 7. Bagging machine according to claim 1, characterized in that it comprises a guiding profile (14) in the vicinity of the upper end of the supply tube for forming a film tube around the latter from a continuous supply of a web of film, said folding means being arranged at the height of said guiding profile (14).