WO2010130403A2

WO2010130403A2 - Equipment for closing and separating crosswise a continuous tubular element for making packaging bags comprising a clamp

Info

Publication number: WO2010130403A2
Application number: PCT/EP2010/002876
Authority: WO
Inventors: Eugenio Toso
Original assignee: V.A.I. S.R.L.
Priority date: 2009-05-15
Filing date: 2010-05-11
Publication date: 2010-11-18
Also published as: ITVI20090116A1; WO2010130403A3; IT1394458B1

Abstract

An apparatus (1) for closing and transverse separation of a continuous tubular element (T) for manufacturing packing sacks (200) which is composed by a vice (2) with two jaws (3) and counteracting jaws (4) spaced at a distance and intersecting in vertical plane the slipping tubular element, (T), a cutting group (5) placed between jaws (3) and connected to them by movement elements (6) suitable for separating contiguous extremities (201) of packing sacks (200) once the two surfaces (T1, T2) of each extremities (201) have been steadily joined by jaws (3) and counteracting jaws (4). The apparatus is provided with a sealing group (7) arranged between the cutting group (5) and each couple of jaws (3) and counteracting jaws (4) suitable for folding and joining the terminal part (202) of extremities (201) stretching out from jaws (3) and counteracting jaws (4) once they have been separated.

Description

EQUIPMENT FOR CLOSING AND SEPARATING CROSSWISE A CONTINUOUS TUBULAR ELEMENT FOR MAKING PACKAGING BAGS COMPRISING A CLAMP. On behalf of the Company V.A.I. S. R. L. - Via Staizza, 54 - 31033 CASTELFRANCO VENETO (TV). DESCRIPTION

The invention concerns an apparatus for transverse joining and cutting of a flexible continuous tubular element particularly suitable for the realization of packing bags. In addition, our invention is concerned especially with vertical packaging machinery supplying packaging sacks.

Moreover, the invention concerns both the method of transverse joining and the method of providing a clip for separating and joining contiguous extremities of packing sacks manufactured in succession from a continuous tubular element.

It is well known that sacks have been always used within the handmade as well as industry sectors for packing small or large quantities of coarse-grained materials such as flour or even meagre quantity of pellets or animal food.. The sack, in fact, is surely one of the most ever used container because of its simplicity and versatility. Whatever material made of, sacks have followed human history because of their light and not too cumbersome features.

In particular, in fact, this long and narrow container can be made of different flexible materials, such as fabric, leather, plastic or paper. It is also well known that different types of sacks have been designed during the last decades: sacks manufactured in jute or cotton fabric with upper and lower openings closed by a stitched seams are surely among the most ancient.. Especially the former ones were once very used. Today moderns sacks more suitable for packing processes and pelletization systems have replaced them because of their scarce practicality and higher costs. In fact stitched seam operations are not fit to today production rhythm. A second typology of sacks, still in use today, are those with a safety valve. As clearly understandable by the name, this type of sacks has an upper double-valve system suitable for filling and emptying the sacks with all kind of products.

Nevertheless, even if more efficient than those in juta or cotton fabrics, these sacks are still too much expensive because of their particular structure (double-valve system) and materials.

A further disadvantage is the fact that their manufacturing method as well as the filling procedure are neither simple nor practical because of the presence of the double-valve system. Moreover this typology of sacks can not be manufactured and filled at the same time. Thus it is necessary to manufacture them before filling the product by the use of a special machinery.

As a result of this, a warehouse is needed to store empty sacks before their use, this being a further disadvantage of this type of sacks. To solve these inconveniences, many companies involved in packing sector, have been managing to find cheaper solutions providing more practical and easy-to-use machineries.

The starting point of these new developing methods in packing, has been the application of the so-called "films", realised in flexible material and wrapped around a coil which is placed upstream in special vertical packing machineries for filling sacks continually and simultaneously. The materials of both the films and the sacks can be any, such as polyethylene, polypropylene and nylon, or composed by many paper layers held together by adhesive strips on external and internal joining areas. As already said before, this new operating method permits the sacks to be filled while they are assembled, thus avoiding the necessity of warehouse to storage them before filling operations. Moreover, no man intervention is required to put the sacks on the filling machine, thus obtaining a nearly constant processing of goods. In fact, the use of one meter diameter coil, can avoid any man intervention for about 8-10 hours..

From a structural point of view, sack manufacturing machines are equipped with un-winder device uncoiling and guiding the flexible material film up to the inlet of a forming tube.

This forming tube coils up the film in a way that its lateral extremities overlap obtaining a tubular shape.

In addition, the machinery is provided with a longitudinal solder bar to better join the tubular element in correspondence to the lateral overlapped extremities.

An apparatus for joining and cutting the continuous tubular element by a desired distance to form sacks is placed at the end of the solder tube. In particular, this special apparatus is equipped with a vice with two opposite couples of false jaws intersecting in a vertical plane the direction of the movement of the tube. When the upper and lower jaws laid open, the tubular element passes through them, the cutting and joining element not operating.

In fact, to form packing sacks out of a continuous tubular element , it is necessary that the two couples of jaws approach the tubular element by a distance equal to the desired spacing of cut-line at the same position at the same time. This operation causes a pressure on the two surfaces that seals the upper extremity of a previous filled sack and the lower extremity of the following sack. Subsequently, the material is transferred into the empty sacks through its upper extremity from an hopper. Moreover, the apparatus for sealing and transverse separation is provided with a cutting group arranged between the double-jaws vice by means of hydraulic rams. When not operating, the hydraulic rams keep the cutting group withdrawn from the jaws. After joining operation, the handling means make the cutting group approaching the tubular film to separate the two adjoining sacks. Finally, once the full sack has been properly closed and separated from the continuous tubular element, it is sent to further working phases by conveyor belt. As previously said, this particular method in manufacturing packing sacks avoid all inconveniences from methods and machines of the past.

Unfortunately this pressing system does not guarantee a perfect closing of the sack, as its extremities might sometimes open during filling process.

In addition, films are very often made by multiple layers of paper, as it is cheaper and more suitable to the transpiration of materials contained in the sacks. As explained above, on external and internal joint areas of the film are previously placed adhesive strips. Sometimes the extremities do not pass the so called drop-test, testing the resistance of filled sacks. The lack of resistance of external parts of sacks is not due to the scarce quality of adhesive strips, but to the fact that material pushed inside the sack may accidentally separate paper from glue. Our invention aims at overcoming all these inconveniences.

Specifically , a first goal is the realization of an apparatus for closing and transverse separation which permits a safer and more reliable closing to be done. A second goal is the creation of an apparatus for closing and transverse separation of sacks capable of successfully manufacturing sacks even from the cheapest materials. Then, a third goal, is the creation of an apparatus that, while manufacturing sacks, makes their filling easier and more practical

Further on, the aim of our invention is to create an apparatus for closing and transverse separation of sacks that makes possible manufacturing and filling sacks simultaneously. Finally, the aim of our invention is the creation of an apparatus making more steady closing of sacks through a lower number of elements and working operation, performing time remaining the same.

All these aims are fulfilled by a an apparatus for closing and transverse separation of packing sacks from a continuous tubular element whose characteristics are set in the appended claims.

Further characteristics are set forth in the dependant claims.

A machine for packaging substances in sacks as well as an apparatus for closing and separating sacks are part of our invention, too. In addition, a method for the transverse closing of the extremities of the tubular element and a method for transverse cutting and lateral closing of contiguous sacks are also part of our invention.

Profitably an apparatus for closing and transverse separation, as well as the concerning methods and packing machine, permits to obtain a significant saving of money thanks to the possibility of successfully manufacturing resistant sacks even from the cheapest materials.

A further advantage is the reduction of man intervention on the working process.

Aims and advantages will be described in detail in the following favourite form of execution which is provided only as a guide rather than a restraining performance according with the following technical tables : picture 1 shows a lateral view of an apparatus for closing and transverse separation - picture 2 shows axonometric view of the apparatus - pictures from 3 to 8 show, from a lateral point of view, the method for transverse cutting and lateral closing of contiguous sacks realised from a continuous tubular element; picture 9 shows lateral view of packing machine for substances in sacks;

- picture 10 show axionometric view of the sack realised with our method and invention.

The whole apparatus for closing and separation is shown in pictures 1 e 2 and it is indicated with 1. As described in detail further on, this apparatus 1 permits closing and separating transversally a continuous tubular element T to manufacture packing sacks 200 as in picture 10. In particular, this tubular element T is made of a laminar film of flexible materials that is wrapped around a coil through a specific process. With regard to flexible materials, they are mainly made of plastic, such as polyethylene, polypropylene or nylon as well as multiple layers of paper or thin cardboard.

As already said, sacks manufacturing and filling are realised through a special packing machine 100 equipped with the apparatus 1 of our invention fully described further up.

The apparatus 1 of our invention is provided with a double-jaws 3 vice 2 opposing two counteracting-jaws 4 that intersect in a vertical plane the running direction D of the tubular element T, as indicated by arrow in picture 1. As said before, the maximum distance between the two double-jaws 4 vices allows the tubular element T to pass through. In the exact moment and position set for closing the extremities 201 of two contiguous sacks 200, each jaw 3 approaches its counteracting one 4 pressing together overlapped surfaces T1 and T2 of the tubular element T₁ as shown in pictures 3 and 4. This approach, in our favourite form of execution is performed thanks to hydraulic rams that guarantee maximum operational reliability . In alternative forms of execution, this approaching movement might be susceptible to variants provided that they fall within the inventive concept and technical note. To make the joint stable between the two surfaces, jaws 3 and their counteracting jaws 4 can be heated using well-known techniques so that adhesive strips on paper or plastic better adhere during the compression. Moreover, jaws 3, and their counteracting jaws 4, are arranged by a same distance I₁ to create an intermediate area on the tubular element which is included between the two contiguous extremities 201.

In our example, as shown in picture 2, on each exposed surface 31 of jaws 3 and counteracting jaws 4 there is a reading which is realised in order to better enforce adherence on the ending segments 201 of sacks 200, when compressed and joined. These exposed surfaces 31 and 41 can be either smooth or moulded differently in case of different working executions, provided that there is prior art. The apparatus for closing and transverse separation 1 is also provided with a cutting group 5 arranged between jaws 3, as shown in picture 2.

In this favourite form of execution, the cutting group is connected to jaws by means of movement 6, handling it forward and backward the tubular element T . These means of movement 6, in fact, keep the cutting group 5 in a rest position, back the jaws 3, so that it does not carry out any cut when jaws approaching their counteracting jaws 4 for joining the tubular element T . Once closed and joined the extremities 201 , these means of movement 6 handle the cutting group forward 5 to execute the cut between the contiguous sacks 201. Once the cut done, the cutting group 5 returns back in its rest position. To realize the separation of the two extremities the cutting group 5 is provided in this form of execution, with a blade 51 not less long than the tubular element T, as shown in picture 1. In different forms of execution, the cutting group 5 might be replaced by equivalent elements provided that there are prior techniques.

Moreover, these elements of movements 6, in the form of execution here described, are provided with an hydraulic ram 61 , handling the cutting group forward and backward. In different forms of execution these elements of movements 6 might be replaced by equivalent elements, provided that they fall within the inventive concept and there is a prior art. In our invention cutting and transverse separating apparatus 1 comprehends a sealing group 7 arranged between the cutting group 5 and each couple of jaws 3 and counteracting jaws, as shown in picture 1. In detail, then, the apparatus 1 of our invention comprehends two sealing groups 7 ,one operating on the upper extremity 201 of a filled sack 200, the other on the lower extremity 201 of a following empty sack 200. Usually, each sealing group 7 has the function of folding and steadily joining the terminal part 202 of extremity 201 stretching out from jaws 3 and counteracting jaws 4.

As it will be described in detail further up, this sealing operation takes place after the separation of the extremities 201. In particular, each sealing group 7, in the favourite form of execution shown in picture 2, is equipped with a folding element 71 , arranged between cutting group 5 and jaws 3 and with a pressing element 72 placed between counteracting jaws 4.

In the favourite form of execution now described, the folding groups 71 belonging to sealing groups 7, are steadily connected to cutting group 5, as shown in picture 1. In different forms of execution these folding groups 71 might be detached from cutting group 5, provided they are completely functional.

As shown in picture 1 , the cutting extremity 52 of blade 51 of the cutting group 5, protrudes from the extremities 8 of folding groups 71.

As explained further up, this feature permits the blade 51 to operate the separation of the extremities 201 before folding their terminal parts 202.

In addition, the free extremities 8 of each folding group 71 of this form of execution has a rounded profile so to form a C shape with adjoining extremities 201- see picture 6.

In different form of execution the free extremities 8 of folding groups

71 might not have a rounded profile, provided that they are completely functional. Each pressing group 72 belonging to sealing groups 7 is pivoted on counteracting jaws 4 - see picture 1- so to make it rotating easily.

Moreover, each pressing element 72 has an inclined surface 9 by the free extremity which is coplanar to internal surface 42 of counteracting jaw 4 when rotated - see picture 7. In the favourite form of execution, the inclined surface 9 is made of gummy material to increase friction and consequently avoid any movement of the terminal part 202 of extremity 201 , as well as any sudden impact stress when inclined surface 9 approaching its counteracting jaw 4. Nevertheless, other materials for inclined surface 9 are not out of the question in different forms of execution.

The advised inclination of the surface 9 should be between 130 and

180 grades to the horizon.

In this favourite form of execution, the grades of inclined surface 9 are 160, so that it is perfectly adjacent to the internal surface 42 of the corresponding counteracting jaw 4. As already said the apparatus for closing and transverse separation that we invented 1 can be installed in specific packing machines 100 for substances in sacks, protected by this patent. A particular form of execution of this machine 100 comprehends an apparatus 101 to uncoil flexible material previously installed- see picture 9.

Flexible material film runs from un-winder device 101 to the inlet of a forming tube 102 making lateral extremities overlapping to obtain a tubular shape. The tubular element T is then subjected to a joining procedure of the overlapped extremities for a better fix.

In fact the packing machine 100 of our invention is provided with a longitudinal closing bar 103 at the end of forming tube 102 to press and fix the extremities longitudinally.

Even in this case, in the favourite form of execution, the longitudinal closing bar 103 is pre-heated to better join the pressed extremities. In other forms of execution, anyway, the bar 103 might not be heated. 103.

The invented machine 100 is also provided with a hopper 104 suitable to convey substances S into sacks while manufacturing. Operation of filling sacks is realised after the lower extremity 201 of sack 200 has been closed through the closing and transverse separating apparatus which is arranged downstream longitudinal closing bar 103. Of course, in different forms of execution, packing machines 100 protected by this patent might have different features provided that there is a prior art and a closing and separating apparatus 1 falling within the inventive concept. A method for transverse closing of a tubular element T for packing substances in sacks different from the one described above 1 is part of our invention, too. In addition, this method includes a pressing operation of the extremities of overlapped surfaces T1 and T2 of a tubular element T. Our method also includes a second folding and joining operation to press terminal parts 202 of the extremity 201 stretching out from the area where the first stable junction is. Understandably, this method aims to give the free initial/ ending extremity of a tubular element T a more stable junction

Nevertheless, to better understand the execution of this method, refer to its description in the following patent and take into consideration that it is might not be carried out by means of our invention apparatus 1. This second method, differently from the previous one, claims a transverse cut and closing of the contiguous extremities of packing sacks manufactured in succession from a continuous tubular element. As previously said, the operations of this method, represented in pictures from 3 to 8, are described when applied to apparatus 1 of our invention. The first operation, indicated by arrows in picture 3 and 4, makes two jaws 3 approaching counteracting jaws 4 so that the two overlapped surfaces T1 e T2 of tubular element T are pressed and steadily joined. Subsequently, a cutting group 5 approaches the area between the two joined extremities 201- see picture 5.

First of all, the cutting group 5 separates the extremities 201 , as the blade 51 protrudes from folding apparatus 71 -see picture 5. Further, the cutting group 5 moves on dragging folding elements 71 that shape into "C" the terminal parts 202 of extremities 201 stretching from jaws 3 and counteracting jaws 4.

As shown in picture 6, this operation is possible thanks to the inclined surface 9 of the pressing elements 72, contrasting backward movement of terminal parts 202 of extremities 201 , thus folded. During the following phase, the cutting group 5 and folding elements 71 are withdrawn in a back position and the concave "C" shape of terminal parts 202 of extremities 201 is free. Now each pressing element 72 rotates around a pivot forward its counteracting jaws 4.

As a result of this approach, the terminal part 202 of the extremity 201 steadily presses the junction by itself. In the end, jaws 3 and counteracting jaws 4 open, free the filled and closed sack while the following one moves forward 200.

We reaffirm that this method is susceptible to variants and can be executed by equivalent apparatus even if not described in here. According to this, we must say that our apparatus 1 , the packing machine 100, as well as the method for transverse closing, transverse cutting and closing, are falling within the inventive concept. In particular the invention reaches the goal of realizing an apparatus for closing and transverse separation capable of making closing and transverse extremities junctions of packing sacks more reliable and safe in comparison with prior art.

A further goal is the realization of an apparatus for closing and transverse separation that, in comparison with prior art, can manufacture sacks even from cheaper materials. It is also fulfilled the goal of realizing an apparatus for closing and transverse separation for easily and practically manufacturing and filling packing sacks.

It is also reached the goal of creating an apparatus for closing and transverse separation that arranged in a packing machine make possible the simultaneous manufacturing and filling operations of sacks. In the end, it is reached the goal of creating an apparatus for closing and transverse separation capable of making stronger the extremities of manufactured sacks with a smaller number of working operations in the same time as prior art. In the execution phase, apparatus of invention, packing machine, method for transverse closing or even method for transverse cutting and joining might be susceptible to variants, that have to be considered protected by this patent even if not described in here.

Claims

1 } Equipment (1 ) for closing and separating crosswise a continuous tubular element (T) for making packaging bags (200), comprising a clamp (2) provided with: - two jaws (3) and corresponding counter-jaws (4) spaced from each other and perpendicular to the sliding plane of said tubular element (T);

- a cutting unit (5) arranged between said jaws (3) and associated with, them through moving means (6) for separating the adjacent ends (201 ) of said packaging bags (200) after moving each one of said jaws (3) near the corresponding counter-jaw (4) and c lamping it in order to permanently join the two opposing surfaces (T 1 ,T2) of each one of said ends (201 ), characterized in that it comprises a sealing unit (7) a rranged between said cutting unit (5) and each pair of said jaw (3) and counter-jaw (4) in order to fold the portion (202) of said end (201 ) that projects from the corresponding jaw (3) and counter-jaw (4) over on itself and successively seal it permanently, after separating said ends (201 ). 2) Equipment (1 ) according to claim 1 ), characterized in that each one of said cutting units (5) comprises a pair of elements made up.-of. a folding means-(71 ) arranged-between said cutting unit (5) and the corresponding jaw (3) and of a corresponding squashing means (72) arranged between said counter-jaws (4). 3) Equipment (1 ) according to claim 2), characterized in that said folding means (71 ) of said sealing units (7) are connected in a permanent manner on opposite sides of said cutting unit (5).

4) Equipment (1 ) according to claim 2) or 3), characterized in that said cutting unit (5) has its cutting edge (52) that projects from each end (8) of said folding means (7). 5) Equipment (1 ) according to any one of the claims from 2) to 4), characterized in that each one of said squashing means (72) is hinged on a corresponding counter-jaw (4) in such a way as to rotate towards it. 6) Equipment (1 ) according to claim 5), characterized in that the surface (9) of each one of said squashing means (72) is inclined in proximity to its free end: in such a way as to perfectly match the internal surface (42) of the corresponding counter-jaw (4) when said squashing element (72) is rotated towards said counter-jaw (4). 7) Equipment (1 ) according to any one of the claims from 2) to

6), characterized in that the free end (8) of each one of said folding means (71) is rounded in such a way as to. fold on itself said portion (202) of said substantially C-shaped end (201 ).

8) Machine (100) for packaging substances (S) in bags (200), of the type comprising:

- an unwinding device (102) suited to unwind a coil of flexible thin material used for making said tubular element (T);

- a forming tube (102) suited to wind said unwound flexible material so that its side ends overlap and define said tubular element (T); - a longitudinal closing bar (103) suited to compress said overlapping side ends and join them longitudinally in a permanent manner;

- a hopper (104) for containing said substance (S) with which said packaging bags (200) will be filled, characterized in that it comprises, downstream of said longitudinal welding bar (1.03),^;the equipment for closing and separating crosswise (1 ) a continuous tubular element (T) according to any one of the preceding claims.

9) Method for closing crosswise the end of a tubular element (T) for packaging substances in bags (200), comprising a first permanent joining operation that consists in moving near each other and compressing the two opposing surfaces (T1.T2) of said tubular element (T) at trie level of said end (201 ), characterized In that it comprises a second operation that consists in folding and sealing through compression the two folded parts of the terminal portion (202) of said end (201 ) projecting beyond the ^;area where, said first permanent joining operation is carried out.

10) Method for cutting crosswise and closing the adjacent ends (201 ) of two packaging bags. (200) obtained; one after the other from said tubular element-, (T); characterized in. that said crosswise separation takes place after the first operation for joining said overlapping surfaces in a permanent manner and before the operation during which each terminal portion of said ends is folded and sealed through compression according to claim 1).