FR2809089A1 - Container to hold granular or powder products is made from one piece plastic material from semi-rigid sheet, has reinforcing mouldings on at least some of wall, and hinged lid provided in one piece with container - Google Patents

Abstract

The container which is in the main four-sided is made from a one piece plastic material from a semi-rigid sheet, and has reinforcing mouldings formed by thermal shaping on at least some of the walls. A lid(9) is provided in one piece with the container and is hinged on the upper edge of the container's rear wall(6). The lid has a snap-in profile(22) which locks into a mating profile(23) on the container. A recess(12) is formed in the lid and fits into a rectangular recess(13) in the upper wall(8) of the container.

Description

 The present invention relates to a container made of semi-rigid material and to a corresponding production method.

The container according to the invention is particularly suitable for granular and powdered products which may be vacuum-packed, or also for liquid products.

For the. packaging of granular, powdery products or in any case having a solid consistency, containers made of flexible sheet material are widely used, for example of the so-called bellows type.

These are obtained in a monolayer or multilayer material, with one or both heat-sealable external faces, for example made of polyethylene. The packaging is obtained in a manner known per se, by successive folding, by carrying out transverse and longitudinal welds between the superimposed parts of the heat-sealable layers.

A notable drawback of these containers is that they do not retain the shape, normally parallelepipedic, if they are not vacuum-packed and, in any case, if they are vacuum-packed, they tend to collapse after the opening.

To remedy these drawbacks, the inventor of the present application, the engineer Luigi Goglio, proposed in EP-A-0 522 326 a container made of flexible material rigidified with a base plate and a cover plate, to resolve the container sag problem.

This solution, even if it is valid, has the disadvantage of using several heterogeneous materials for the constitution of the container, in particular a flexible sheet material, and rigid parts, in a suitable plastic material, which are joined to the flexible sheet before constituting the container.

Another drawback of this solution is that, in correspondence with the opening for taking the product, a separate cover is normally provided, as well as a peelable sealing sheet joined to the aforementioned rigid parts.

The objective of the invention is to eliminate the above-mentioned drawbacks, and in particular to provide a semi-rigid container which always retains its shape, regardless of the quantity of product contained therein and the fact that it is packaged. in an inert or pressurized atmosphere.

Another object of the invention is to provide a container which is capable of being produced in a simple and economical manner from a single sheet of monolayer or multilayer plastic material, for example with the technique of so-called bellows containers.

Another object of the invention is to provide a container which is completely hermetic, which has a pleasant aesthetic appearance and which has a greater internal volume compared to the containers of basically the same dimensions. Another object of the invention, again, is to provide a container which, if necessary, makes it possible to maintain an internal pressure greater than that possible with the containers made of flexible material.

Another object of the invention is to provide a container which is sufficiently rigid so as to withstand the vertical and horizontal thrusts.

These objectives are achieved by the container and by the corresponding production process, the container being essentially rectangular in shape, comprising a bottom wall, two side walls, a rear wall, a front wall and a top wall, and characterized in that this container is made of a single piece of semi-rigid plastic sheet and has stiffening deformations on at least some of its walls, and the process for producing such a container comprising the following phases - thermoforming, in the pre-established zones , deformations on the corresponding walls of the container, on a strip of semi-rigid material which is moved intermittently; - slicing the blank of each container, without however separating it from the strip, and grooving the fold lines of the container; - sending the strip of semi-rigid material to a forming mandrel with rectangular section, where a first welding is carried out so as to produce a flange, on the periphery of which are successively disposed the upper wall, the front wall, the lower wall and the rear wall of the container, performing a lower transverse weld to close one of the side walls and separating a shaped blank from the next, so as to determine an open container in correspondence with the other side wall; - filling the container through the open side wall and final welding of said open side wall.

Advantageously, the container has at least one of the following characteristics - it is provided with a cover forming a single body with the container; - Said cover is articulated along a hinge axis in correspondence with the upper edge of the rear wall of the container, and has at least one locking system suitable for being applied by means of a complementary system provided on the container, for closing the lid; - On at least one of the free perimeter sides of this cover is provided a corresponding flap which is folded inside said cover; - the stiffening deformations are obtained by thermoforming of the semi-rigid sheet material; - one of these deformations is provided on the front wall of the container and consists of a bulge having an external convexity; - This bulging on the front wall of the container essentially concerns the entire width of the wall, extending from one side wall to the other of the container, and forming two small horizontal rabbet walls, respectively lower and upper; - In this upper wall, an essentially rectangular recess is provided; - On the cover is provided a recess able to be housed in the recess of the upper wall; - on the bottom wall of the container, a concave deformation is provided, determining at least a couple of small vertical walls projecting opposite; - This concave deformation has an essentially rectangular outline, so that it can be inserted into the recess of the upper wall of the container or into the recess of the cover, to allow the stacking of several containers; - it is obtained from a single blank following folding along grooving lines constituting the separation edges between the upper wall, the front wall, the lower wall and the rear wall of the container, of a weld along the rear wall to produce a flange, and bellows folds with successive welds to shape the side walls; - It includes a degassing valve capable of maintaining a slight internal overpressure of the container; and - in correspondence with the upper wall, there are provided lines for pre-incision or reduction of the material capable of facilitating rupture during the opening phase of the container.

The method advantageously further comprises the following characteristic during the thermoforming phase, a cover of the container is also shaped with the deformation and the reciprocal latching systems, cover which is closed on the container after the filling phase. The container according to the invention has a box shape, essentially parallelepipedic, and has appropriate stiffening deformations, advantageously obtained by thermoforming.

In particular, the front wall of the container has a bulge - or external convexity - which, in addition to stiffening this wall, determines an increase in volume of the container, as well as a particular aesthetic appearance thereof.

On the bottom wall of the container is provided a stiffening deformation determining a concavity external to the rectangular profile, which matches a corresponding rectangular recess cut in the cover of the container.

Advantageously, the cover forms a single body with the container and is closed by a hinge on the upper wall of the latter, where another rectangular recess is provided capable of housing the corresponding rectangular recess of the cover.

Advantageously, the upper wall of the container, in correspondence with the aforementioned recess, has pre-incision or reduction lines of the material, so as to facilitate the opening of the container, without otherwise compromising the tightness of the container before opening .

Fixing systems between the lid and the container are also provided, to guarantee the closure of the container after the first opening. The container according to the invention is obtained by means of folding and successive welding, from a single blank of semi-rigid plastic.

In particular, the process for the production of the container made of semi-rigid material, according to the invention, consists in starting from a continuous film of semi-rigid plastic material, mono or multilayer, in subjecting this material to thermoforming to establish the deformations stiffening aforementioned, to perform grooving along the fold lines to obtain the container, to incise the film along the outline of the development in plan of the container, without causing the detachment of all the blank, so that it this can be carried by the film to a forming mandrel where the container is shaped.

The other characteristics of the invention will appear clearer from the detailed description which follows, which is given in a purely explanatory form and therefore not limiting of its implementation, illustrated in the attached drawings, among which: FIG. 1 is a schematic axonometric view of a container made of semi-rigid material according to the invention; Fig. 2 is a plan view from the top of the container of FIG. 1; Fig. 3 is a plan view from below; Fig. 4 is a side elevational view taken from the left side of FIG. 2; Fig. 5 is a section taken along the line V-V in FIG. 2; Fig. 6 is the plan development of the container of FIG. 1; Fig. 7 is a section taken along the line VII-VII of FIG. 6; Fig. 8 is an axonometric view illustrating an intermediate phase of the constitution of the container of FIG. 1; Fig. 9 is a schematic block view, illustrating the method of constituting the container according to the invention, starting from a reel of sheet material.

Referring to the appended figures, and for the moment to figures 1 to 5, the container according to the invention, particularly for granular or powdered products such as coffee or similar products, has been generally indicated by the number of reference 1.

This has an essentially parallelepiped shape and is produced from a single blank 2 (Fig. 6) made of flexible material, as will be better said later.

The container 1 comprises a bottom wall 3, two side walls 4 and 5, a rear wall 6, a front wall 7 and an upper wall 8, surmounted by a cover 9. The side walls and the rear wall are normally smooth, while shapings are provided on the other walls, obtained by thermoforming of the plastic material constituting the container.

In particular, a deformation 10 is provided on the lower wall 3 with a concavity facing outwards, which develops between the rear and front walls of the container and is delimited by two corresponding small projecting walls 11.

The contour of the concave deformation 10 has a rectangular profile, as can be seen in FIG. 3, and it is designed so as to marry a corresponding rectangular recess 12 cut in the cover 9, so as to allow the stacking of several containers.

The rectangular recess 12 cut in the cover 9, in turn, joins a corresponding underlying rectangular recess 13, cut in the upper wall 8 of the container.

The upper wall 8 as well as the cover 9 of the container have their respective perimeter edges 14 and 15 rounded.

The cover 9 is a single body with the rear wall 6 of the container and it opens around a horizontal upper hinge axis 16. On its front, the cover 9 has a small vertical wall 17 which covers a corresponding upper section 18 of the front wall 7 of the container, and a horizontal section 19 which is arranged on a corresponding horizontal rebate of said front wall 7 of the container. The profile of the cover 9 continues with another vertical wall 21 ending in a tab 22, which hangs below a relief 23, provided in correspondence with the front wall 7 of the container, so as to establish a closure by latching of the cover 9 on the container. The tab 22 also acts as a gripping element to facilitate lifting of the cover 9.

Finally, the cover 9 has respective side walls 24, with the lower edge 25 inclined downward from the rear hinge axis 16 towards the lower edge of the front wall of the cover.

The front wall 7 of the cover finally has a bulge 26, with an external convexity, which develops practically between the side walls 4 and 5, so as to determine the upper horizontal rebate 20 and a corresponding lower horizontal rebate 27.

The front bulging 26 of the container 1, in addition to stiffening the wall, by the presence of the small horizontal walls 20 and 27, determines a significant increase in the internal capacity of the container, as is seen in particular in the section of FIG. 5, and also gives the container a particular shape with a pleasant aesthetic appearance, as well as substantial stiffening in the vertical and horizontal directions.

The container 1 according to the invention is obtained from a single blank 2 shown in FIG. 6 and in the section of FIG. 7, where the reference numbers of the various parts of the container have been reported. Furthermore, as can be seen in FIG. 6, grooving lines are provided to facilitate the folding of the blank 2 along these, in order to obtain the container 1.

In particular, the folds are initially carried out around the grooves 30, vertical in FIG. 6, determining the separation edges between the upper 8, front 7, lower 3 and rear 6 walls of the container. We therefore heat seal a terminal edge 31 of the blank 2, provided at the end of the upper wall 8 and provided with several horizontal cuts 32, on the internal surface of the part of the blank determining the rear wall 6 and two small side walls 33 adjoining it.

After these operations, the container takes a tubular shape, as shown in FIG. 8.

Then, the flange is closed at one end, for example by forming the side wall 5, by performing a bellows folding around the grooving lines 34, so as to superimpose the side wall 5 on a small corresponding wall 33, by performing a heat sealing at least along the terminal edge 33 thereof.

At this time, the container which has an open end can be filled with product and therefore sealed by performing another bellows folding along the grooving lines 35, to form the other side wall 4, as described in substance for the side wall 5.

The container is thus hermetically closed, and the cover 9, designed to form a single body with the container, can be closed by snapping onto it, thanks to the latching systems 22 and 23, by simply serving as an element for blanket.

As can be seen in FIG. 6, the cover 9 is made rigid by folding towards the inside thereof the relative flaps 36, designed to correspond to its three free perimeter sides, and by heat-sealing these flaps inside the cover.

Naturally, instead of the abovementioned heat seals, provision may be made for suitable bondings, especially in the case where the inner layer of the blank 2 is not heat sealable.

In order to facilitate the opening of the container 1, on its upper wall 8, in correspondence with the recess 13, a pre-incision or reduction line 40 is provided, shown in dotted lines in FIGS. 6 and 8, and visible in the section of FIG. 5 where it appears as a cut in the sheet material so as to reduce the thickness, in any case guaranteeing continuity and therefore the hermetic nature of the closure of the container. In this way, in the opening phase, it suffices to exert a pressure in correspondence with the recess 13 of the upper wall of the container to cause the rupture of the sheet material along said reduction line 40, material which can be removed by a simple pull.

Naturally, other means can be provided to cause the opening of the container, such as for example a catch tab or similar means. Naturally, the container according to the invention can be provided with a degassing valve, not shown, for example that described in the inventor's patent EP-A-0 659 657, to allow the controlled outlet of the gases generated by the packaged product, for example ground coffee.

Thanks to the greater robustness of the semi-rigid material constituting the container, according to the invention, and to the adequacy of the deformations provided therein, this degassing valve can be adjusted to intervene at a pressure slightly higher than the pressure usual, so as to maintain a certain internal overpressure of the container, which makes it possible to better preserve the shape and accentuate the "belly" determined by the bulge 26 provided on the front wall 7 of the container.

Referring now to FIG. 9, the method of manufacturing the container 1 according to the invention is schematically explained.

A strip or film 51 of semi-rigid sheet material is unwound from a reel 50, it is passed through at least one deflection roller 52, several pairs of drive rollers 53 and at least one other roller of return 54, to be sent on a forming mandrel 59 with rectangular section after being subjected to a series of operations.

In particular, a preheating station 55 is provided, where the strip 51 is preheated to be deformed by thermoforming in a station 56 immediately following, with a vacuum system or with a matrix and a counter-matrix, according to techniques known in them. - same. Next comes a cooling station 57 and a station 58 for slicing, grooving and folding the outer edges 36 of the cover 9.

In practice, at the exit from station 58, a succession of blanks 2 are cut on the strip 51, oriented in the transverse direction of the strip, as schematically shown by the enlargement reported in FIG. 9. Obviously, these blanks 2 are not completely sliced but remain attached to each other on the strip 51 and driven between the pairs of rollers 53 to the deflection roller 54 to then be sent around the forming mandrel 59, where the containers 1 are shaped in the manner which has been previously described with special reference to FIGS. 6 and 8.

The containers 1, at their exit from the forming mandrel 59, as they are shown diagrammatically in FIG. 9, have the shape of a rod, as shown in FIG. 8.

These tubes are then welded on their lower part in a station 70, as shown diagrammatically in the figure, and sent to a filling station 60 where the containers open on their upper part are filled with product, to then be sent to another station. solder 61 which performs the upper soldering of the containers.

Next comes a station 62 for folding the upper and lower welded edges, a station 63 for rotating and closing the cover 9, to form the container 1 shown in the figure at the outlet of the line. It is obvious that the various phases schematically illustrated in FIG. 1 are purely indicative and that some of these can be grouped or interchanged.

Naturally, the invention is not limited to the particular embodiment previously described and illustrated in the accompanying drawings, but many modifications of detail can be made to it without departing from the scope of the invention itself, thus that it is defined in the claims which follow.

Claims (16)

<U> CLAIMS </U> 1. Container of essentially parallelepiped shape, comprising a bottom wall (3), two side walls (4, 5), a rear wall (6), a front wall (7) and a top wall (8), characterized by the fact that this container (1) is made from a single piece of semi-rigid sheet plastic and has stiffening deformations on at least some of its walls (3, 4, 5, 6, 7, 8). 2. Container according to claim 1, characterized in that it is provided with a cover (9) forming a single body with the container (1). 3. Container according to claim 2, characterized in that said cover (9) is articulated along a hinge axis (16) in correspondence with the upper edge of the rear wall (6) of the container, and has at least one latching system (22) adapted to be applied by means of a complementary system (23) provided on the container, to establish the closure of the cover. 4. Container according to one of claims 2 and 3, characterized in that on at least one of the free perimeter sides of this cover (9) is provided a corresponding flap (36) which is folded inside said lid. 5. Container according to any one of the preceding claims, characterized in that the stiffening deformations are obtained by thermoforming of the semi-rigid sheet material. 6. Container according to any one of the preceding claims, characterized in that one of these deformations is provided on the front wall (7) of the container and consists of a bulge having an external convexity (26). 7. Container according to claim 6, characterized in that this bulge (26) on the front wall (7) of the container relates essentially to the entire width of the wall, extending from one side wall to the other of the container, and by forming two small horizontal rebate walls, respectively lower (27) and upper (20). 8. Container according to any one of the preceding claims, characterized in that in this upper wall (8), a substantially rectangular recess (13) is provided. 9. Container according to claim 8 and any one of claims from 2 to 7, characterized in that on the cover (9) is provided a recess (12) able to be housed in the recess (13) of the upper wall (8). 10. Container according to any one of the preceding claims, characterized in that on the lower wall (3) of the container (1), a concave deformation (10) is provided, determining at least a pair of small vertical walls opposite in projection (11). 11. Container according to claim 10, characterized in that this concave deformation (10) has an essentially rectangular contour, so as to be able to be inserted in the recess (13) of the upper wall (8) of the container (1 ) or in the recess (12) of the cover (9), to allow the stacking of several containers. 12. Container according to any one of the preceding claims, characterized in that it is obtained from. of a single blank (2) following folding along grooving lines (30) constituting the separation edges between the upper wall (8), the front wall (7), the lower wall (3) and the rear wall (6) of the container, a weld along the rear wall (6) to produce a rod, and bellows folds with successive welds to shape the side walls (4, 5). 13. Container according to any one of the preceding claims, characterized in that it comprises a degassing valve capable of maintaining a slight internal overpressure of the container. 14. Container according to any one of the preceding claims, characterized in that, in correspondence with the upper wall (8), there are provided lines for pre-incision or reduction (40) of the material capable of facilitating breaking thereof. during the container opening phase. 15. Method for the production of a semi-rigid material container according to any one of the preceding claims, comprising the following phases: - thermoforming, in the pre-established zones, deformations (10, 13, 26) on the corresponding walls (3, 8, 7), from the container, on a strip of semi-rigid material (51) which is intermittently advanced; - slicing the blank (2) of each container (1), without however causing its separation from the strip (51), and grooving of the fold lines of the container; - sending the strip of semi-rigid material (51) to a rectangular section forming mandrel (59), where a first weld is carried out so as to produce a rod, on the periphery of which the upper wall (8) are successively disposed ), the front wall (7), the bottom wall (3) and the rear wall (6) of the container, performing a lower transverse weld to close one of the side walls (4, 5) and separation of a blank shaped with the following, so as to determine an open container corresponding to the other side wall (5 or 4); - filling the container through the open side wall and final welding of said open side wall. 16. Method according to claim 15, characterized in that during the thermoforming phase, a cover (9) of the container is also shaped with the deformation (12) and the reciprocal latching systems (22, 23), cover which is closed on the container after the filling phase.