ES2383405B1 - PROCEDURE AND MACHINE FOR THE PACKAGING OF LIQUID PRODUCTS. - Google Patents

Abstract

Procedure for the packaging of liquid products in a train of flexible containers devoid of upper base, to which an intermittent advance is printed, in which from a band folded on itself and subsequently sealed transversely to form a succession of containers with two side walls facing and open at one of its ends, the process comprises the cross-cutting operations of the band to individualize the packages; filling and closing of the containers by juxtaposition and heat-bonding of said side walls by their extreme edges, in which, prior to filling the containers, in addition to performing the transverse seal of the band also join partially the extreme edges of the side walls of the packages along at least one section that reaches a corresponding transverse seal, the open end of the packages being partially closed and thus providing them with a reduced filling opening.

Description

Procedure and machine for the packaging of liquid products.

Technical sector of the invention

The invention relates to a process for the packaging of liquid products in a container train, bag type or bag, devoid of upper base, to which an intermittent advance is printed on an automatic packaging machine. The invention is particularly applicable in machines that have work stations, for example for the preparation of the container, for its filling and subsequent sealing, and of means for transporting the containers from one station to the next.

The invention also relates to an automatic packaging machine specially adapted for the implementation of the process.

Background of the invention

Numerous embodiments of automatic packaging machines are known in which the products are packaged in bags or sacks of a flexible material.

It is also known that these machines comprise means for making the bags or sacks from a continuous band of flexible and heat-weldable material, which in turn can be obtained from the longitudinal joint of two or more starting sheets, which is transversely sealed and at intervals for the formation of a succession of packages that will later be individualized by cutting the sheet precisely by said transverse seals.

The format of the bags or bags can vary depending on the longitudinal folds that are practiced in the sheet, which can give rise, for example, to simple envelopes, of essentially quadrangular format, or bags that can be kept standing, when the container is provided with a bottom bottom by folding the sheet in W. In the field of technique this type of bags are called Stand-up Pouches or Doypack.

In any case, the body of the packages, whether they are bag or bag type, is formed by two facing walls and joined along two vertical seams, formed when the respective transverse seals of the sheet are made, which in a forming phase is opened superiorly to allow the filling of the containers by this open end.

In general, two types of machines are distinguished, such as those described above, depending on the progress of the sheet and the packages once they have been identified. This distinguishes intermittent feed machines and continuous feed machines.

The first type allows fixed work stations to be arranged on the chassis of the machine, in which the packaging, filling and finishing operations are carried out and in synchronized form, for example, while the band and the individualized packages are maintained static Once the operations that are carried out in the work stations are finished, as if it were a chain, the band and the containers are advanced in unison a position so that the corresponding operations in the following are carried out on them workstation.

Under the described operating conditions, the chain, that is the container train, cannot advance until all the work stations have completed their task. A bottleneck that limits the advance of the container train is located at the filling station. This means that the time required to fill a container in the process of being manufactured is a variable that affects the productivity of the machine. The waiting time between consecutive filling operations will depend on the volume and physical properties of the product to be packaged, but also on the characteristics of the devices used to introduce the product into the containers, for example the dispensing nozzles and the filling flow rate.

To date, it is endeavored that the containers have an opening or mouth opening that is as wide as possible so that the opening of the package allows the product to be dosed using a nozzle with a larger diameter and to minimize the dosing time, and consequently the waiting time between two consecutive filling operations.

However, it turns out that the packaging capacity of the machines is then conditioned by the travel speed of the container train between the stations, it being observed that this travel speed must be reduced to a very important extent when the product to be packaged is a liquid product

or semi-liquid In fact, once a container has been filled with the dose of liquid, the start-up and transport of the container from the filling station to the closing station of the container, and the subsequent stop maneuver, it produces inertial movements of the liquid contained in the container still open These movements cause swells in the liquid that can be poured outside or wet parts of the package on which sensitive operations must be carried out ahead, such as the thermal welding of the upper edges of the walls of the container in order to close the container superiorly . To avoid this inconvenience it is essential to work at low travel speeds, which affects the productivity of the machine.

Alternatively, oversized containers with respect to the dose of liquid to be contained can be formed so that the free surface of the liquid is further away from the upper edge, that is to say of the mouth of the container, so that waves or splashes do not reach the open top edge of the container. The drawback associated with this solution is an increase in the manufacturing cost when more material is used per unit of packaging.

It is therefore an objective of the present invention a process that allows to increase the productivity of these machines, without necessarily affecting the manufacturing cost or even reducing such costs.

Explanation of the invention.

To solve the problems described above, a procedure for the packaging of liquid products in a flexible container train, bag type or bag, devoid of a top base, to which an intermittent advance is printed, is disclosed. from a band folded on itself and subsequently sealed transversely to form a succession of packages with two side walls facing and open at one of its ends, the process comprises the cross-cutting operations of the band to individualize the packages; filling the containers through said open end; and of closing or sealing of the containers, by juxtaposition and heat-bonding of said side walls by their extreme edges.

In essence, the procedure is characterized in that, prior to filling the containers, in addition to the transverse seal of the band, the aforementioned end edges of the side walls of the packages are also partially joined along at least one section which it reaches a corresponding transverse seal, partially closing the open end of the containers and providing them with a reduced filling opening.

In a variant of the process, the aforementioned end edges of the side walls are joined in each package along two sections that reach the respective transverse seals that laterally close the package, providing said container with a central filling opening.

Preferably, the joint or partial joints of the end edges of the walls are carried out simultaneously and with the same welding tool that transverse sealing of the band is practiced.

Contrary to the trend that follows in the art, the inventors have resolved, instead of looking for an opening as wide as possible, partially closing the filling opening of the containers which causes, as will be explained in greater detail below. , that the liquid that tends to protrude from the container is redirected back into the container.

The fact of having to use smaller nozzles, in accordance with a reduced container opening, means a longer dosing time to deliver the dose of the liquid product to be packaged. This side effect would have deterred the expert from applying a solution according to the invention.

The inventors have proven, however, that this increase in dosing time is compensated by the increase in the speed that can be printed on the full and open containers during transport to the next work station even when they contain non-viscous liquids.

In a variant of the process, the welding tool that performs the transverse seal of the folded band comprises a welding head essentially configured in a T-shape, in which a straight main portion is distinguished and of length equal to or greater than the height of the folded band, and at least one lateral extension at the upper end of the main portion, preferably being two lateral and opposite extensions, which extend in a direction perpendicular to said main portion.

Preferably, the two lateral extensions of the welding head are symmetrical with respect to the main portion.

In order that the dosing time does not condition the cadence of the machine, if it becomes the new bottleneck, the invention contemplates using dynamic dosing techniques.

Accordingly, in an embodiment of the invention, the filling operation is performed by means of a filling nozzle that is kept inserted in the containers, through its filling opening, for a part or all of the time that passes while the advance of the container train is being made.

The invention contemplates the use of a main camshaft whose uninterrupted rotation triggers along a complete turn the operations that are simultaneously carried out on the train of containers while they remain static and the operation of advance of the containers, of a station to another that is consecutive, the speed of rotation of the aforementioned main camshaft being variable along the same turn, following a pattern of speed variation that is repeated at each turn that said main shaft performs.

In accordance with another aspect of the invention, an automatic packaging machine is disclosed, comprising means for intermittent entrainment of a band folded on itself so that two opposite walls are distinguished therein for the formation of the side walls of a succession of packages, the machine comprising a welding tool adapted to make successive transverse seals in the said folded band that joins the said side walls of the band by heat sealing and along vertical seams, the machine being characterized by the tool of Welding comprises two welding heads facing each other and capable of approaching and moving away from each other, between which the folded band is arranged, a straight main portion having a length equal to or greater than the height of the folded band being distinguished in the heads, and at least one lateral extension at the upper end of the main portion pal, which extends in a direction perpendicular to said main portion and which is intended to heat weld a section of the end edges of the facing walls of the folded web.

In one embodiment, the welding heads comprise two symmetrically arranged lateral extensions with respect to the main portion.

The invention contemplates incorporating into the machine a filling group in which a filling nozzle is mounted with displacement capacity following a path coinciding with the displacement path of the container train.

Brief description of the drawings

Fig. 1 shows a diagram of formation of a succession of packages according to a variant of the invention;

Fig. 2 is a schematic view of a machine for practicing the method according to the invention;

Figs. 3a, 3b and 3c are enlarged views of parts of Fig. 2 indicated by corresponding balloons;

Fig. 4 shows a container in the process of being manufactured during transport in the direction of a closing station in a conventional procedure; Y

Fig. 5 shows a container in the process of being manufactured during transport in the direction of a closing station in a variant of a process according to the invention.

Detailed description of a variant of the invention

The variant of carrying out the procedure explained below is carried out in a process for the manufacture of packages 1 obtained from a single flexible band, the packages being able to remain in an upright position once filled.

In order to obtain the packages 1 from a single continuous starting band, in a known way the band is folded longitudinally by making a triple fold whose fold lines are parallel to each other, to form two side walls and a bottom wall whose section Transversal adopts a “W” configuration.

In general, welds are made along the joining lines between the bottom wall and the side walls, as well as between facing portions of said bottom wall to form a deformable bottom in the form of an inverted dome 9 (see Fig. 5) when the container is full, which does not protrude from the essentially elliptical perimeter, formed by the connecting lines between said bottom and the corresponding sides, which serves as a support base and on which the full container is held upright.

Details for the preparation of such a fund is described for example in patent document GB 2014539.

Fig. 1 illustrates the formation diagram of the packages once the bottom described above has been prepared. In this Fig. 1 it is observed that successive transverse seals 15 are made on the folded band 11, forming a succession of open pockets superiorly in the folded band 11, which will subsequently be individualized, by cross-section of said folded band 11 along the transverse seals 15, to obtain a train of individual packages 1. In these individualized packages 1, shown at the right end of the diagram of Fig. 1, two side walls 3 and 4 are distinguished along vertical seams 7 and 8.

The method comprises the subsequent operations of filling the containers 1, through their open ends, and closing or sealing the containers 1, by juxtaposition and heat-bonding of the opposite side walls 3, 4 of the containers 1, by its extreme edges, as will be explained later.

In Fig. 1 it is observed that when the transverse seal 15 of the folded band 11 is made, its end edges are also partially joined along two sections 5, 6 that link with said transverse seal 15, the opening of the the pockets, giving future containers a reduced opening 2.

In the example of Fig. 1, a welding tool with a welding head 10 essentially formed in a T-shape is used, in which a straight and equal length main portion 12 is distinguished

or greater than the height (h) of the folded band 11, and two lateral extensions 13a, 13b and opposite at the upper end of the main portion 12, which extend in a direction perpendicular to said main portion. This head is represented in Fig. 1.

The purpose of joining along the upper sections 5, 6 the upper edges of the folded band 11, thereby obtaining a reduced opening 2 for the containers 1, is explained below.

Fig. 4 shows a moment in the transport operation of a full container 1, still to be closed, if proceeding according to a current procedure in which the containers 1 is not provided with a reduced opening 2, and a cadence is applied above a security threshold. According to this procedure, the vertical seams 7, 8 extend straight to the mouth of the container 1, leaving a maximum upper opening 16 to be able to perform the filling operation by means of a filling nozzle as wide as possible. Subsequently, the container 1 filled but open superiorly is transported in the direction of the work station where the closing operations of the container 1 are carried out. During this transport maneuver, the accelerations and decelerations of the package 1 produce waves in the liquid content that causes the pouring of the contents to the outside and / or the wetting of sensitive parts of the container, such as the upper edges 3a, 4a of the side walls 3, 4 of the container 1 that must be subsequently joined by heat welding.

Fig. 5 shows the effect that occurs in the liquid contained in the container 1 if it is proceeded according to the invention.

In the formation of the container 1 of Fig. 5, when the transverse seal 15 of the folded band 11 is made, its end edges have also been partially joined as indicated in the diagram of Fig. 1, so that the edges 3a, 4a upper of the opposite side walls 3, 4 of the container 1 are also joined along the sections 5, 6, which reach the respective side seams 7 and 8. Consequently, in the container 1 obtained two upper seams are distinguished that partially close the container 1, and which provide it with a reduced central opening 2 compared to the opening 16 of the container of Fig. 4.

As a result, even when the container is filled with more liquid, as illustrated in Fig. 5, the upper seams interfere with the swell of the liquid and when it reaches the top of the container it is redirected back to the central part of the container , without spilling out.

In practice this means that either the containers can be filled with more liquid or that for the same amount of liquid to be introduced into the containers they can be made smaller, saving on material.

In practice, by means of the process of the invention, the capacity of the packages 1 being manufactured can be optimized from 13% to 15%.

Although in the diagram of Fig. 1 and in the package of Fig. 5 the upper edges 3a, 4a of the opposite side walls 3, 4 have joined along two horizontal strips, it is also contemplated to make connections with others formats, for example trapezoidal.

Fig. 2 shows a machine 100 for implementing the procedure illustrated in the diagram of Fig. 1.

Machine 100 conventionally comprises means for unwinding a roll of a continuous band and for longitudinally folding it by making a triple fold whose fold lines are parallel to each other. The folded band 11 obtained has two side walls and a bottom wall whose cross section adopts a "W" configuration.

In the direction of advance of the folded band 11, the machine 100 has a lower welding group 101, to make the bottom of the packages; and a transverse weld tool 9 of the folded web

eleven.

This transverse welding tool 9 is formed by two pairs of welding jaws, each pair comprising respective welding heads 10 facing each other and capable of approaching and moving away from each other, between which the folded band 11 is arranged.

The jaws are mounted rotating around a common axis, so that the jaws of the same pair can move away from each other and approach following a movement similar to that of a clamp during its opening and closing maneuvers.

The detail of Fig. 3a shows the upper part of the heads 10, the upper part of its main portion 12 and its lateral extensions 13a, 13b being symmetrically arranged with respect to said main portion.

In each operating cycle of the machine 100 each pair of jaws makes a corresponding transverse seal 15 on the folded band 11, two transverse seals 15 being carried out at the same time.

In the detail of Fig. 3b the union of the upper edges of the folded band 11 is shown, that is the upper edges of the opposite side walls of the future containers 1, joined along the sections 5, 6.

The machine comprises downstream of the transverse welding tool 9 means for pleating 102 or ironing the folded band 11; control means 103 such as encoders and photocells; and transverse cutting means 104 of the folded band 11.

Once the containers 1 are individualized, the machine has opening means 105 of these and a filling group 106 of the containers.

Conventionally, the machine comprises a main camshaft whose rotation triggers in a synchronized manner all the operations that are simultaneously carried out on the containers in each work station and also the operation of transferring the containers from one station to another. With each complete turn of the main camshaft the machine performs a corresponding duty cycle. The time that elapses from when a container is delivered to a station until it is delivered in the next station is the time that a work cycle lasts.

The invention contemplates that in order to increase the speed of advance of the containers between two consecutive stations, the average speed of the main camshaft between two predetermined angular positions can be increased, among which said main camshaft seeks to drive the means provided in the machine for the advance of the folded band and of the packages once individualized. Alternatively or simultaneously, the angular path can be altered during which the said main camshaft attempts to drive the means provided in the machine for the advancement of the folded band and the packages.

Returning again to Fig. 2, the filling group 106 of the machine 100 depicted employs a dynamic dosing solution. Specifically, the filling group 106 is formed by what would become two consecutive work stations. That is, the dosing operation is carried out during two consecutive cycles of the machine 100, so that the dosing is started when the container is static in a first station 106a, it is not interrupted during transport of the container to a second station 106b, and it continues during the first moments in which the container is static in said second station 106b, all taking into account that the transport time between the stations is shorter in relation to a conventional procedure due to the effect produced by the joint along of sections 5, 6 of the upper edges of the opposite side walls of the folded band

eleven.

In practice, the increase in the dosing time of introducing a certain dose of liquid into the container through a narrower nozzle 14, in accordance with the reduced openings 2 of the containers 1, is compensated by the joint fact that faster transfer can allow more dosing time during the same work cycle while the container is static and that the dynamic dosing allows dosing of the product while the transfer is carried out.

To implement this variant of the invention represented in this Fig. 2, the dosing is carried out by means of a filling nozzle 14 that moves with the containers 1, so that it is introduced through the opening 2 of the containers 1 and it is introduced inside while the advance of the container train 1 takes place from the first station 106a to the second station 106b.

In practical cases, the increase in the dosing time that is achieved by proceeding in this way reaches 20% with respect to the available dosing time if this dynamic dosing solution is not used, while the machine cycle time, function between Other factors of the speed of transfer of the containers between two consecutive stations, can be reduced by 15%.

Naturally, the invention is applicable both for containers in which a spigot is arranged between the opposite side walls of the container during the closing operation, and for containers without pouring or opening means, in which no element is disposed between said opposite side walls of the container during the closing operation.

Claims (11)

1.- Procedure for the packaging of liquid products in a train of flexible containers (1), bag type or bag, devoid of upper base, to which an intermittent advance is printed, and in which from a folded band ( 11) on itself and subsequently transversely sealed to form a succession of packages with two side walls (3, 4) facing and open at one of its ends, the process comprises the cross-cutting operations of the band for individualizing the packages; filling the containers through said open end; and of closing or sealing of the containers, by juxtaposition and joining by heat welding of said side walls (3, 4) by their edges (3rd, 4th), the procedure being characterized because prior to filling the containers ( 1), in addition to the transverse seal of the band, the ends (3a, 4a) ends of the side walls of the containers are also partially joined along at least one section (5, 6) that reaches a corresponding transverse seal (15), partially closing the open end of the containers and providing them with a reduced filling opening (2). 2. Method according to the preceding claim, characterized in that in each package (1) said ends (3a, 4a) ends of the side walls (3, 4) are joined along two sections (5, 6) that reach the two consecutive transverse seals (15) that laterally close the package, giving said container an opening (2) central filling. 3. Method according to any one of the preceding claims, characterized in that the joint or partial joints of the edges (3a, 4a) ends of the side walls (3, 4) are carried out simultaneously and with the same tool of welding (9) performed by the transverse seal (15) of the folded band (11). 4. Method according to the preceding claim, characterized in that the welding tool (9) comprises a welding head (10) configured essentially in a T-shape, in which a straight main portion (12) is distinguished and of equal length or greater than the height (h) of the folded band (11), and two lateral extensions (13a, 13b) and opposite at the upper end of the main portion, which extend in a direction perpendicular to said main portion. 5. Method according to the preceding claim, characterized in that the two lateral extensions (13a, 13b) of the welding head (10) are symmetrical with respect to the main portion (12). Method according to any one of the preceding claims, characterized in that the filling operation is carried out by means of a filling nozzle (14) that is kept inserted in the containers (1), through its filling opening (2), for part or all of the time that elapses while the advance of the container train is being carried out. 7. Method according to any one of the preceding claims, characterized in that it comprises the use of a main camshaft whose uninterrupted rotation triggers along a complete turn the operations that are simultaneously carried out on the container train while they remain static and the operation of advancing the containers, from one station to another that is consecutive, the speed of rotation of the aforementioned main camshaft being variable along the same turn, following a pattern of repeated speed variation on each lap that said main tree performs. 8.- Automatic packaging machine (100), comprising means for intermittent dragging of a folded band (11) on itself so that two opposite walls are distinguished therein for the formation of the side walls (3, 4) of a succession of packages (1), the machine comprising a welding tool (9) adapted to make successive transverse seals (15) in the aforementioned folded band (11) joining the said side walls of the band by heat welding and along vertical seams, the machine being characterized because the welding tool (9 ) comprises at least two welding heads (10) facing each other and with the ability to approach and move away from each other, between which the folded band (11) is arranged, distinguishing in the heads a straight and equal length main portion (12) or greater than the height (h) of the folded band (11), and at least one lateral extension (13a, 13b) at the upper end of the main portion (12), which extend in a direction perpendicular to said main portion (12) and which is intended to heat weld a section (5, 6) of the edges (3rd, 4th) of the opposite walls of the folded web. 9. Machine according to the preceding claim, characterized in that the welding heads (10) comprise two lateral extensions (13a, 13b) symmetrically arranged with respect to the main portion (12). 10. Machine (100) according to any one of claims 8 or 9, characterized in that it comprises a filling group (106), in which a filling nozzle (14) is mounted with displacement capacity following a path coinciding with the path of displacement of the train of containers (1).  Fig. 1 15 15 8 7 8 7 13b  Fig. 5   SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 201230350 SPAIN Date of submission of the application: 09.03.2012 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: B65B9 / 093 (2012.01) B31B23 / 00 (2006.01) RELEVANT DOCUMENTS

Category

56 Documents cited Claims Affected

A A A A

US 4216639 A (GAUTIER) 12.08.1980, column 3, line 30-column 9, line 40; drawings. EN 2193888 A1 (BOSSAR, S.L) 01.11.2003, the whole document. US 5687549 A (JOSTLER ET AL.) 18.11.1997, column 3, line 5-column 8, line 15; drawings. US 4810109 A (CASTEL) 07.03.1989, summary; claim 1; figures. 1-10 1-10 1-10 1.8

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been prepared • for all claims • for claims no:

Date of realization of the report 06.06.2012

Examiner V. Anguiano Mañero Page 1/4

REPORT OF THE STATE OF THE TECHNIQUE Application number: 201230350 Minimum documentation searched (classification system followed by classification symbols) B65B, B31B Electronic databases consulted during the search (database name and, if possible, terms of search used) INVENES, EPODOC, WPI State of the Art Report Page 2/4  WRITTEN OPINION Application number: 201230350 Date of Completion of Written Opinion: 06.06.2012 Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 1-10 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-10 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published. State of the Art Report Page 3/4  WRITTEN OPINION Application number: 201230350  1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

US 4216639 A (GAUTIER) 12.08.1980

D02

ES 2193888 A1 (BOSSAR, S.L) 01.11.2003

D03

US 5687549 A (JOSTLER et al.) 11/18/1997

D04

US 4810109 A (CASTEL) 07.03.1989

 2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement The first claim describes a process for the packaging of liquid products in a flexible container train with intermittent advance in which from a folded band comprises the cross-cutting operations of the band to individualize the packages, filling them, closing or sealing and thermal welding of the side walls, in which, in addition to the transverse seal of the band, the end edges of the side walls of the packages are also partially joined. US 4216639 A, D01, describes a process for manufacturing flexible containers of two compartments with intermittent advance formed from folded sheet (claim 1, summary) that differs from the first claim in the welding of the side walls. The rest of the documents cited in the search report describe procedures for obtaining flexible bags, which differ essentially in the welding and arrangement thereof. Therefore, claim 1 meets the patentability requirements set forth in articles 6, 8 and 9 of the patent law. In turn, claims 2-7 depend on the first and verify the patentability criteria. The eighth claim describes an automatic packaging machine comprising means for the dragging of a folded web, welding tool for sealing transversely in the web by heat-welding, two facing welding heads distinguishing in the heads a straight main portion and a lateral extension at the upper end of the main portion to heat-weld a section of the end edges of the facing walls. Document D01 describes an automatic packaging machine comprising belt and folding drag means, with cutting and welding means (column 3, lines 40 65). Welding is not carried out with the distinction of two heads (column 4, lines 25-30) in order to delimit zones or bands in the upper part of the bag. On the other hand, document ES 2193888 A (D02) describes a horizontal machine for the formation and filling of flexible containers with a stable bottom, but with a different welding system (column 5, lines 4-17). The other documents essentially differ in welding, but also in the final result of the upper seams of the package. For these reasons, the eighth claim meets the patentability requirements set forth in articles 6, 8 and 9 of the patent law. In turn, claims 9 and 10 depend on the eighth and verify the patentability criteria. State of the Art Report Page 4/4