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METHOD FOR PACKAGING LIQUID OR POWDERY PRODUCTS IN CONTAINERS OF SEMI-STIFF MATERIAL

TECHNICAL FIELD

The present invention relates to the packaging of liquid or powdery products.

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Particularly the invention relates to a method for packaging products, particularly alimentary liquids, by using semi-stiff containers preferably made of cardboard coated with polythene.

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BACKGROUND ART

Methods and machines, for carrying out containers 20 made of semi-stiff cardboard and for filling these latter with liquid or powdery products, are known for some time.

A first so-called "vertical" machine (the

25 "form-fill-seal" machine) includes the unrolling of cardboard from web, therefore the passage of this latter onto a so-called "tie" fitted to make a tubular element in which it has been made a bottom by means of a first transversal welding and inside

30 which it is subsequently dosed the product to be packed, thus, at a preset distance from this latter, it is again welded transversely in such a way so-called "under beating" . Such tubular element is therefore cut in the median zone of this latter

35 welding so as to cut away, from the tubular element,

a first container filled with the product and to make the bottom of the tubular element that is the bottom of the following container.

This vertical machine is designed for containers not very capacious so as to hold at maximum a litre of product because the bottom welding of the tubular element must support the whole column of poured liquid inside the tubular element: therefore this welding could break if 3 or 5 litres of product must be packed inside a single container. In this case the weight that this bottom welding must support increases enormously of even 10-15 times in comparison with the carrying out and the filling of containers of maximum one litre, also by virtue of the fact that the tubular element is always normally filled with a product amount that is 2 or 3 times greater than the which one that will be contained in each container.

Often this machine comprises moreover the fastening of a closing element, both a tab and a cap, on the pouring opening of the container before the filling step of this latter. This operation causes a considerable slowing down of the operative functionality of the machine giving in addition a series of drawbacks prevalently due to the fact that this closing element must be applied during short times and therefore, for instance, by means of toxic adhesive having rapid desiccation.

A further machine includes the preventive erection of tubular flattened blanks, the possible fastening of a closing element onto the pouring hole of the container, the carrying out of the bottom of each

container, the filling of this latter with the product to be packed and finally the closing of the container top.

This machine has in addition to the disadvantages above mentioned for the vertical machines also the disadvantage resulting from a considerable cost increase for carrying out such containers, because it must be used a refolded and welded tubular blank that is therefore more expensive than a web wrapped material.

All these systems for carrying out containers and for filling them with liquid or powdery products must to be considered "monobloc" because they have the feature of joining inseparably the carrying out of the container with the subsequent filling of the same with the product to be packed. This jeopardises the modularity of the machines making difficult their carrying out and maintenance.

A further considerable disadvantage presented by the known machines is that no control for the true container tightness is performed before filling thereof.

The containers carried out with such machines has often hinge caps glued onto the external edge of the pouring opening of the container that is previously closed by a tab glued or heat sealed onto the edges of the opening and is fitted to make the tightness of the container once this latter is filled.

Thus, the cap has not generally tightness and guarantee seal so as to guarantee that it cannot be

opened before the first fruition of the product inside the container. This does not guarantee at all that the zone included between the tab and the overhanging cap cannot be contaminated, because this latter could be unintentionally or voluntarily open at any moment of the packaging or transport or public display until the real first fruition moment of the product packed in the container.

A further disadvantage is that the filling level of each container is fairly aleatory because said machines perform the hermetic closing of a relatively wide area of each container when this latter is already be filled and thus the container is closed when it is not completely shaped and its related volumetry is not precisely established.

DISCLOSURE OF THE INVENTION

The main object of the present invention is therefore to provide a method for packaging liquid or powdery products inside the containers made of semi-stiff material so as to ensure the maximum hygienic guarantee and the whole preservation of each container at least up to the first fruition of the packed product.

A further object is to provide a method for packaging liquid or powdery products that can be implemented in modular machines in which the carrying out of the single containers is made by a module independent from the which one that make the filling of the containers with the product that must be packed.

Further object of the invention is to provide a method so as to package mostly liquid products into containers of any capacity, besides being able to check their possible tightness before their filling.

Another object of the invention is to provide a method allowing a precise metering of the product to be packed inside each container.

Other object is to provide a simple and effective method of easy fulfilment, of sure effectiveness and of reliable cheapness.

The aforesaid objects are achieved with a method for packaging preferably liquid or powdery products in containers made of semi-stiff material, partially opened in correspondence of a welding zone and provided with a pouring spout at the edges of which at least a closing element is fixed and is fitted to be opened and closed again so as to carry out the tightness of said pouring spout, said method being characterised in that it includes : the sealing of said welding zone fitted to close hermetically the cited empty container; the opening of said closing element in such a way to allow the flux communication between the inside of the container with its outside; the feeding of the cited product within the container itself through the cited pouring spout; the subsequent tight closure of said closing element; the fastening of a seal strip in correspondence of the cited closing element fitted to warrant the sealing up to the first fruition of the cited packed product.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention are pointed out in the following, with reference to the enclosed drawings, in which:

- Figure 1 is an axono etric view of a container during the different packaging steps of a product therein according to the method of the present invention;

Figure 2 shows an axonometric view of the container of figure 1 during a step succession according to the two variations of the method;

Figure 3 shows an axonometric view of the container of figure 1 during a step succession according to a further variation of the method.

BEST MODE OF CARRYING OUT THE INVENTION

With reference to the figure 1, numeral 1 indicates a container made of semi-stiff material, preferably made of cardboard coated by polythene with or without the interposition of an aluminium sheet, in correspondence of its opened A configuration, as for instance it is before its filling with a machine, known and not shown, at the end of its shaping. Normally the container 1 is left opened in correspondence with a welding zone 10, mainly to the top of the container, and it has a closing element 3 applied onto the edges of one its pouring spout 2 and so as to make the tightness of this latter. It is necessary to specify that this closing element is, for instance advantageously, of the so-called type hinge cap, as it is shown in the figures 1 and 2, but it can also be of the unscrewing type, that is cap-spout, without invalidating the method afterwards described.

The method includes the step succession schematically illustrated in figure 1 with the configurations from A to F assumed by each semi-stiff container 1.

Therefore the method includes the sealing of the welding zone 10, for instance along its opposed flaps 10a and 10b, in such a way to make hermetically closed the empty container 1, that is without being filled, in any way, with the product to be packed, as it is shown in the configuration B of figure 1.

The configuration C of the container 1 shows the opening step of the movable portion 3a of the closing element 3 so as to put in flow communication the inside of the container with its outside through its pouring spout 2.

The configuration D of the container 1 shows the metering of the product to be packed within the container by means of the insertion, for instance, of a proportioning nozzle 7 into the pouring spout 2 and the subsequent delivery of a predetermined amount of product to be packed through the same nozzle.

The configuration E of the container 1 shows the closure of the closing element 3 by means of the hermetic coupling between its movable portion 3a and the fixed one 3b anchored to the external surface of the container 1.

In the case in which the closing element 3 is of the type cap-spout, known and not shown, and it is

therefore constituted by a coupling cap with a spout previously fixed onto the container 1, the method comprises the subsequent closure of the element 3 by means of the coupling, for instance by screwing, of the cap to the corresponding spout.

In the configuration F of the container 1 it is shown the already made fastening of a seal strip 8 in correspondence of the closing element 3, for instance crossing longitudinally the whole cap 3 until jutting out bilaterally from the same. Such strip 8 is fitted for warrant the sealing and the consequent not tampering guaranty of the cap 3 till its removal in correspondence of the first fruition of the product packed in the container 1.

A method variation is shown in the figure 2 and it includes the same step succession corresponding to the container conditions from B to F. In other words, the method does not include the first step of closing the container 1 when it is empty but, on the contrary, it includes the step of opening the closing element of a closed empty container.

A further variation of the method includes the step succession corresponding to the configurations C , D, E and F of the container 1 shown in the figure 2. Practically the method does not include the first step of closing neither opening the closing element 3 of the container 1 because this element 3 is fixed in open way to the container. In fact upstream this latter is carried out closed with the exception of the opening of the pouring spout 2, around the edges of which the fixed portion of the closing element 3 is applied, that for instance is the base of the

hinge cap or the screw cap spout. In the configuration C , thus the container 1 has the closing element 3 in an open configuration.

Another variation of the method is shown in figure 3 in which the container 1 has a first configuration A' where this latter is partially opened in correspondence of both the welding zone 10 and the pouring spout 2, because the closing element is applied at the open configuration around the edges of this latter.

The method according to this variation therefore includes a first sealing step of the welding zone 10, for instance along the opposed flaps 10a and 10b of the container 1, and than it goes with the succession of the corresponding steps between the configurations D to F of each semi-stiff container 1, schematically shown in figure 3.

Both to the method object of the present invention and to its aforesaid variations it could be added a fastening step of an hermetic closing tab 9 of the pouring spout 2 subsequently to the product metering within the container 1, schematically shown in the configuration G of this latter in the figures 1, 2 and 3.

Particularly, the tab 9 could be indifferently fastened closed to the edges of both the pouring spout 2 and the fixed portion 3b of the closing element 3 bounded to the container 1.

It is important to notice that the method includes the filling of each container by means of a

proportioning device 7 that, if suitably checked, is able to fill the container to a preset level by virtue of which a fruition of the packed product is achieved without overflowing or undesired leakage.

The implementation of this method with the packaging machines does not involve any productive slowdown because the different method steps could be quietly activated in parallel without complicating at all the carrying out of the same machines. Moreover each container is extremely stable and not subject to deformations during its transport on a substantially horizontal plain during the whole step succession for carrying out the aforesaid method.

The method with all its aforesaid variations can moreover includes a further step for checking the container tightness by means, for instance, of the air insufflation inside the container before its filling or by means of its full immersion, known and not shown, of the container 1 into a liquid in correspondence of the configuration B.

Thus the aforesaid method allows advantageously to use containers of any capacity in correspondence of their perfectly stable condition during their filling because each container is previously fully shaped and does not require any particular manipulation during its filling step, besides offering the possibility of checking the tightness of the container before its filling.

A further advantage of the present invention is to provide a method for packaging liquid or powdery products inside containers made of semi-stiff

material so as to assure the maximum hygienic guarantee and the full preservation of each container at least up to the first fruition of the packed product.

Another advantage is to provide a method for packaging liquid or powdery products able to be implemented with modular machines in which the carrying out of the single containers is made by means of a module independent from the remaining machine.

Further advantage of the invention is to provide a method allowing a precise metering of the product to be packed inside each container.

Another advantage is to provide a simple and effective method of easy realisation, of sure effectiveness and of checked cheapness.