EP2230074A1 - Method for manufacturing a string of sachets provided with a slide - Google Patents

Abstract

The method involves using a longitudinally folded plastic material sheet (2) or two distinct sheets for defining two parallel walls. A connecting region of the parallel walls is formed for providing an M-shaped gusset profile. Complementary closing profiles are longitudinally fixed on opposite surfaces of the gusset profile. Packaging sachets (S) are individualized by forming a separation (25) and a welding perpendicular to the closing profiles. A slider (5) is placed on the closing profiles before individualizing the sachets.

Description

The present invention relates to a method of manufacturing a string of packaging bags formed of two walls.

An example of application of such bags is the packaging of food products, for example frozen.

The documents EP-B-0 205 852 and WO-A-94/19250 describe facilities and methods for manufacturing plastic packaging bags with complementary opening and closing profiles.

According to these documents, the sachets are manufactured in the form of a string of juxtaposed sachets, the general direction of the latter (that is to say that which is oriented from the top to the bottom of the sachet) being perpendicular to the longitudinal direction of the rosary.

The bags are joined at their apex by a common longitudinal band - we speak of suspension band - which allows them to move together from station to station for the implementation of different operations.

The present invention aims to improve the manufacturing process of such a string.

• délimités par des bords longitudinaux dits supérieur et inférieur, et des bords transversaux,
• individualisés deux à deux, au moins partiellement, par une séparation parallèle auxdits bords transversaux,
• tous solidaires de deux bandes longitudinales, dites de suspension, elles-mêmes solidaires respectivement d'une paroi correspondante,

les parois étant pourvues, au voisinage de l'un des bords longitudinaux et parallèlement à celui-ci, de profilés de fermeture complémentaires,
selon lequel on met en oeuvre les étapes suivantes :

1. a) on utilise une feuille de matière plastique repliée longitudinalement sur elle-même, ou deux feuilles distinctes, pour délimiter lesdites deux parois parallèles ;
2. b) on conforme la région de raccordement des parois de ladite feuille pour lui donner un profil à soufflet en "M" ;
3. c) on fixe longitudinalement lesdits profilés de fermeture complémentaires sur les faces en regard de ce soufflet, et, ensuite
4. d) on individualise, lesdits sachets deux à deux, en réalisant une séparation et une soudure perpendiculaires audits profilés,

caractérisé par le fait qu'on met en place un curseur sur lesdits profilés avant la mise en oeuvre de ladite étape d).It is therefore related to a method of manufacturing a string of packaging bags formed from two walls, these bags being:

• delimited by so-called upper and lower longitudinal edges, and transverse edges,
• individualized two by two, at least partially, by a separation parallel to said transverse edges,
• all secured to two longitudinal strips, said suspension, themselves secured respectively to a corresponding wall,

the walls being provided, in the vicinity of one of the longitudinal edges and parallel to it, with complementary closure profiles,
according to which the following steps are implemented:

1. a) using a sheet of plastic folded longitudinally on itself, or two separate sheets, to delimit said two parallel walls;
2. b) conforming the connection region of the walls of said sheet to give it an "M" bellows profile;
3. c) longitudinally fixed said complementary closure profiles on the faces opposite this bellows, and then
4. d) individualized, said bags two by two, performing a separation and welding perpendicular profiles profiled,

characterized in that a cursor is placed on said profiles before the implementation of said step d).

• on met en oeuvre une étape a') selon laquelle on fixe une bande de suspension, longitudinalement, le long de chacun des bords libres desdites parois ;
• ladite étape a') est mise en oeuvre par soudage ;
• à l'étape a'), on fixe lesdites bandes de suspension sur les faces en regard desdites parois ;
• à l'étape a'), on utilise des bandes initialement réunies, que l'on sépare l'une de l'autre après mise en place ;
• on met en oeuvre lesdites étapes a), a'), b) et c), dans cet ordre ou dans un ordre différent ;
• à l'étape a), on utilise une ou deux feuilles dont une extrémité constitue une bande de suspension longitudinale ;
• en lieu et place de l'étape c), on utilise des profilés venus de matière avec lesdites parois.

According to other advantageous characteristics:

• a step a ') is implemented according to which a suspension strip is fixed longitudinally along each of the free edges of said walls;
• said step a ') is carried out by welding;
• in step a '), said suspension strips are fixed on the opposite faces of said walls;
• in step a '), initially used bands are used, which are separated from each other after placement;
• said steps a), a '), b) and c) are carried out in that order or in a different order;
• in step a), one or two sheets are used, one end of which constitutes a longitudinal suspension strip;
• in place of step c), the profiles used are made of material with said walls.

• les figures 1 et 2 sont des vues schématiques d'une installation de mise en oeuvre dudit procédé, la figure 1 représentant la partie amont de cette installation, tandis que la figure 2 en représente la partie aval,
• la figure 3 est une vue en coupe, selon le plan III-III de la figure 1, d'une feuille de plastique en cours de transformation selon le procédé de l'invention,
• la figure 4 est une coupe analogue à celle de la figure 3, selon le plan IV-IV de la figure 1, à un poste de l'installation situé en aval par rapport au précédent.

Other features and advantages of the present invention will appear on reading the detailed description which will follow and which will be made with reference to the appended drawings, in which:

• the figures 1 and 2 are schematic views of an installation for implementing said method, the figure 1 representing the upstream part of this installation, while the figure 2 represents the downstream part,
• the figure 3 is a sectional view, according to plan III-III of the figure 1 of a plastic sheet being transformed according to the method of the invention,
• the figure 4 is a cut similar to that of the figure 3 according to plan IV-IV of the figure 1 , at a post of the facility located downstream from the previous one.

The method according to the invention can be implemented by means of an automated installation such as that shown schematically in FIG. figure 1 .

This installation 1 comprises different stations through which passes a sheet 2 consisting of a plastic film, and at which it undergoes operations and / or transformations.

In the embodiment given below, use is made of a single sheet 2 for making bags. However, it is quite possible to consider using two different sheets, which are fixed to one another, for example by welding.

On the other hand, when the term "sheet" is used, it is meant a single-or multi-material sheet, in this case mono-or multi-layer.

The movement and the path of the sheet 2 is symbolized by the arrows f, g, h and j figures 1 and 2 .

The station located furthest upstream of the installation 1 comprises a rotary roller 10 of axis X-X 'on which is disposed, in the form of a coil, said sheet 2. This latter has a very great length.

The sheet passes over a series of parallel return rollers 11, 12 and 13, which give the sheet a horizontal direction of movement, in the direction of the arrow f .

Once it has passed the roller 13, the sheet comes into contact with a shaper 3 of known type, called "folding triangle", which is adapted to fold the sheet 2 on itself, according to a median fold longitudinally .

A horizontal roller 14, of axis YY 'perpendicular to the three preceding rollers, is disposed at the exit of the shaper 3, so that, after this roll, the folded sheet undergoes a horizontal movement symbolized by the arrow g.

The sheet then has the configuration illustrated in figure 3 , which means that it consists of two superimposed and parallel walls 21 and 22, connected by a fold 23.

The fold 23 is in the form of an "M" bellows (or "W" depending on the direction), this particular configuration being made possible by the fact once the roller 14 has been crossed, an elongated member, for example in the form of a finger, is pushed against the fold of the sheet so as to impart to it this particular configuration.

The sheet is then conveyed, using two rollers 14 and 16 of axis YY ', arranged vertically to one another, in a vertical downward path (arrow h ).

During this downward movement, the sheet is subjected to two different operations.

The first is implemented at the longitudinal free edge 210 of the walls 21 and 22 of the sheet, as it appears in FIG. figure 4 .

This is the establishment of a sheet called "suspension sheet" 6 which is fixed along the free edge 210 of the walls 21 and 22 of the sheet 2.

This is a suspension sheet conveyed by reference rollers referenced 18 and 19 which, using a shaper similar to that already described, proceed to its folding and allow its engagement, as shown in FIG. figure 4 against the opposite faces of the walls 21 and 22 of the sheet 2.

The sheet 6 initially consists of two parallel strips 60, joined by a fold 61 in an arc, their mutual joining zones being provided with a bulge or ring 62.

However, in an alternative embodiment, one can very well consider that the strips 60 are in one piece with the walls 21 and 22 which they then constitute the extension. In this case, the ring 62 may be formed by winding on itself the free edge of the strips 60 and melting of this winding.

On the other side of the sheet 2, that is to say at the level of the bellows F, there are two different operations.

The first is made by means of a roller 17 on which is wound a strip 3 formed of two complementary closure profiles 30 and 31 engaged with each other.

These are well-known complementary profiles, already used on many packaging bags and whose complementary closure members are, for example, constituted by male and female elements, by hooks, or by any other means of this. kind.

At this station, the band 3 is placed inside the bellows F, so that the complementary profiles 30 and 31 are placed facing each other against the faces 230 and 231 of the bellows F. Their attachment at this level is for example made by welding.

In an alternative embodiment, it is possible to make use of a sheet 2, the sections 30 and 31 of which are integral with it.

We then proceed immediately to the placement on these profiles, a set of sliders 5 of a type known per se.

These are sliders able to urge said profiles, respectively to the opening and closing, by moving along them.

These sliders are stored in a vibratory bowl 40 and placed on the profiles by an automaton 4.

This implementation, carried out by spacing the wings of the sliders, is of course sequentially, so that an identical pitch separates two adjacent sliders along the sheet 2.

Once this sheet has crossed the roller 16, it then undergoes a strictly horizontal displacement (see figure 2 ). It is then conveyed to a station 7, in which the suspension sheet 6 is welded between the walls 21 and 22 of the sheet 2. More precisely, the parallel strips 60 are welded to the opposite faces of the walls 21 and 22. .

Immediately at the exit of this station is the cutting, by means of a blade 7, the sheet 6 so as to open the fold 61 and separate the longitudinal strips 60 from one another.

At a station 8, alternating cuts 24 are made of the two walls 21 and 22, intended to facilitate subsequent opening of the individual bags.

Finally, at station 9 is performed the individualization of the bags, this by means of a transverse orientation blade, which materializes a separation 25 and simultaneously proceeds to the welding of the walls 21 and 22 to define the transverse edges of the bags.

At the exit of this station, the bags S are then in the form of a chain C, all integral with the suspension strips 60.

At this point, the string of sachets (and their associated suspension bands) is conditioned. It will be used later for filling the bags.

In a variant, however, it is possible to carry out this operation directly.

In this case, it is then possible to give this string a vertical orientation, such that the bags are "suspended" from the strips 60.

It is then conceivable to fill them by the opening that constitutes the space between two alternate cuts 24.

During this operation, the goods flow along the strips 60 to the inside of the bags S, without any risk of material retention at this level.

Once filled, the bags are closed by means of a weld line that extends below and parallel to the alternate cuts 24.

Finally, we proceed to the separation of the bags, by a longitudinal cut, made just above the aforementioned weld line.

According to the invention, the placing of the bags on the sheet 2 before individualization of the bags is particularly effective because the sheet has, at this stage, a unitary character, which means that it is deformed little.

If we consider, on the contrary, to set up the sliders once the bags individualized, then we should keep them in place individually, which would be particularly restrictive.

The first opening of the bags is done by moving the slider 5 along the profiles 30 and 31 and perforating the bellows F. To facilitate this operation, a pre-cut of the sheet may be considered.

Finally, it will be noted that it is possible to first fix the sections 30 and 31 on the walls 21 and 22, then to engage the slider 5 thereon. Alternatively, it is also possible to first engage the cursor on the profiles, then to fix this set on the walls.

Claims (8)

A method of manufacturing a string (C) of packaging bags (S) formed of two walls (21, 22), these bags (S) being: delimited by longitudinal edges said upper (210) and lower (23), and transverse edges (26), - individualized two by two, at least partially, by a partition (25) parallel to said transverse edges (26), - all integral with two longitudinal strips (60), said suspension, themselves secured respectively to a corresponding wall (21, 22), the walls (21, 22) being provided, in the vicinity of one of the longitudinal edges (210) and parallel thereto, with complementary closure profiles (30, 31),
according to which the following steps are implemented: a) using a sheet (2) of plastic folded longitudinally on itself, or two separate sheets, to delimit said two parallel walls (21, 22); b) the connection region of the walls (21, 22) of said sheet (2) is conformed to give it an "M" bellows profile (F); c) longitudinally fastening said complementary closure profiles (30, 31) on the faces (230, 231) facing said bellows (F), and then d) said bags (S) are individualized in pairs by separating (25) and welding perpendicular to said profiles (30, 31), characterized by the fact that a slider (5) is placed on said profiles (30, 31) before the implementation of said step d). Process according to Claim 1, characterized in that a step a ') is carried out according to which a suspension strip (60) is fastened longitudinally along each of the free edges (210) of said walls (21). , 22). Process according to claim 2, characterized in that said step a ') is carried out by welding. Method according to claim 2 or 3, characterized in that , in step a '), said suspension strips (60) are fixed on the opposite faces of said walls (21, 22). Process according to one of Claims 2 to 4, characterized in that , in step a '), bands (60) which are initially combined are used, which are separated from one another after being used. square. Process according to one of Claims 2 to 5, characterized in that the said steps a), a '), b) and c) are carried out in this order or in a different order. Process according to Claim 1, characterized in that , in step a), one or two sheets (2) are used, one end of which constitutes a longitudinal suspension strip (60). Method according to one of the preceding claims, characterized in that instead of step c), profiles (30, 31) made of material with said walls are used.

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