EP3237298B1

EP3237298B1 - Improved wrapped bundle package formed with stretching plastic film and provided with a gripping handle

Info

Publication number: EP3237298B1
Application number: EP15826141.2A
Authority: EP
Inventors: Alessandro Cattaneo
Original assignee: Krones AG
Current assignee: Krones AG
Priority date: 2014-12-22
Filing date: 2015-12-22
Publication date: 2019-03-13
Anticipated expiration: 2035-12-22
Also published as: WO2016102581A1; CN107108091A; EP3237298A1; CN107108091B

Description

Field of the Invention

The present invention relates to a package of a bundle of containers, in particular bottles, that is, a unitary, compact wrapping of a bottle assembly, formed by means of a thin film of plastic material.
The bundle is a typical secondary wrapping, widely used (in particular in the sector of large-scale distribution) in the field of drinks, because it is typically transparent, light, quick to apply in large scale and inexpensive. Normally it is suitable to contain six bottles of plastic material, containing mineral water or other drinks. The reference to this type of bundle - here and in the following of the present description - however, is given as an example, but it is understood that the invention finds application also to other types of wrapping of a group of small objects.

State of the Prior Art

In the field of plastic film wrappings, it is largely known the use of heat-shrinking plastic material. A film of heat-shrinking plastic material is wound around a group of containers (for example six bottles), arranged side by side to form an array of three rows on two lines, and then it undergoes heat-shrinking within an oven, to cause the shrinking of the film and thus form a compact and largely stable bundle package.
The drawbacks and the high cost of such a bundle package of heat-shrinking plastic material are described in the introductory part of WO2015040565 , in the name of the same Applicant.
In order to partly overcome these problems, already in document EP-197574 a different solution has been proposed for the wrapping of parcels - which can also be pack of bottles - with stretching film, that is, film which does not need to undergo heat-shrinking.
This solution consists in causing a sequence of group of items to progress continuously, mutually shortly distanced along a feeding line, and to wind a film of stretching plastic in the form of continuous spiral around each one of the packs which progress, providing to then severe the packs one from the other with a cutting device. After a first coil of film is wound and the bundle is separated from the other items, the same bundle is rotated by 90° and wound with a second coil of film at 90° with respect to the previous one.
The technique described in this document has been then further improved with the procedures described in WO2015040565 in the name of the same Applicant. A type of stretching plastic particularly suited to these purposes is furthermore described in WO2015001516 .
The bundle wrapping is by its very nature highly inexpensive because it is very simple, hence it requires little material and a quick and elementary processing. The accessory elements of a bundle are hence very few: among these there are any supports or printable elements with graphic indications, gripping means and other systems for opening facilitation.
With reference to gripping means, it must be noted that the bundles, however they are manufactured, are usually provided with a handle or grip, so that the user is facilitated in the purchase and transport operation. A variety of different handles suited for the purpose exist, which provide to join an additional element (in the form of a band of plastic or paper material or mixed) to the bundle surface, for example by gluing or hot welding. This element evidently affects wrapping costs in a non-negligible way. Some examples of the prior art are described in EP647198 , FR2880000 , EP2112089 , EP2589545 .
While all these solutions are by now consolidated in the field of bundles of heat-shrinking material, by its nature tenacious and little elastic, no fully effective system has been identified yet in the field of stretching films. As a matter of fact, these films, maintain by their nature a certain residual elasticity after the application and hence tend to unduly elongate following a concentrated load (as could be the joining point of a handle). Moreover the wrapping process with stretching film does not provide heat sources, hence specific welding units for the handle only should be provided.
As mentioned, it has been furthermore proposed to provide easy-opening means for easing the wrapping opening, typically in form of pre-cuts or weakening lines, exploiting the natural trend of the heat-shrunk plastic material to quickly severe itself in the proximity of start cuts of the break. Examples of these systems are described in EP717712 and EP868364 .
These opening means, except for special cases, evidently affect very little the cost of the wrapping. However, they have also rooted in the sector the conviction that each cut of the wrapping must be carefully arranged in the areas not undergoing natural stresses, so that the bundle does not accidentally break when it is lifted and transported, but can instead open when the user acts voluntarily in the suitably provided pre-cut areas. This is why, in the field of plastic film wrapping cuts in the film are practiced only in few cases and only in position where they can ease opening of the package but where no stress is applied during handling of the bundle.
Where other cuts/opening are provided in the plastic film, they are arranged in advance with proper cutting on the plane film and possibly with reinforcing elements, like in GB1403912 . This however, requires a complicated arrangement to align the pre-cut film to the bundle of items. The only case where some cuts made in the package are tolerated, is when the film shall undergo a heat-shrinking process, which allows to properly hot-weld the edge of the cuts, so as to prevent the cut being deformed and widening upon application of stress. In this case - like for example disclosed in US4130201 - the package is expensive, since it requires heat-shrinking plastic and heat source, while it is uncomfortable to be grasped by hands (since the edge of the cuts is hardened by the heat-shrinking process) .
Documents US 4050220 and US 4596330 concern similar wrapped packed bundles made of stretchable film material but the first one named does not disclose a handle and the second one does not disclose the spiral wrapping.

Brief Description of the Invention

The problem at the bottom of the invention is therefore to propose a structure of a plastic film package also provided with a gripping handle, which is overall highly inexpensive, effective and provided with a rather strong handle but at the same time pleasant for transporting the bundle.
This object is achieved through the features mentioned in claim 1. The dependent claims describe preferential features of the present invention.
In the conviction that the stretching plastic material, by its nature and due to the specific application way, is the one best suited to obtain significant wrapping savings, it has also been surprisingly detected that it is relatively little prone to problems deriving from cuts - with appropriate arrangement of the film and or relative cuts thereof - and is hence perfectly suited to define very simple gripping handles.
In particular, following the wrapping of the bottles with two opposite coils of stretching film, suitably oriented each other with respect to the longitudinal axis of the bundle, it is possible to practise two crosswise slits to the coil winding axis, in the depressed area of the wrapping, producing a controlled releasing of the stress in the film, which results in a controlled stretching of the film during handling of the bundle package, which in turn inhibit propagation of the incision and generates instead a central creasing having sufficient resistance and rigidity to lift the product. As a matter of fact, the elastic return forces, still present in the stretching material, upon releasing through cuts, tend to curl the material towards the central band between the two cuts, which can then effectively perform the handle function.
The effectiveness of this arrangement is the greater, the more the wrapping material is chosen with elongation features suited to the application, so as not to suffer from an excessive elongation of conventional stretching materials (which provide elongations up to 300%) which, despite being resistant to traction in the direction of the length of the wrapping film, could allow a handle elongation incompatible with the transport function of the bottle load. A particularly suited material is, for example, the stretching film manufactured by BIA Srl and described in WO2015001516 , with maximum elongation in the order of 20%.

Brief Description of the Drawings

Further features and advantages of the invention are in any case more evident from the following detailed description of a preferred embodiment, given purely as a nonlimiting example and illustrated in the attached drawings, wherein:

fig. 1 is a perspective view from above of a bottle bundle package, according to the invention, as manufactured in a wrapping station;
fig. 2 is a perspective view similar to that of fig. 1, which shows the same wrapping in which two crosswise cuts have been practised; and
fig. 3 is a plan perspective view from above, which also shows a hand grabbing the central gripping band of the bundle.

Detailed Description of a Preferred Embodiment

As schematically illustrated in fig. 1, a bottle bundle package is obtained by applying a wrapping of stretching plastic film P onto a group of bottles or other containers B.
In particular, according to the invention, the wrapping of stretching plastic film is obtained by applying two series of counter-rotating coils of plastic film onto bottles B. That is, on containers B a first band of film is wound according to a spiral with a first sense of rotation (for example right bound) around a longitudinal wrapping axis; subsequently it is wound, above the first layer of film, a second band of film according to a spiral with a second sense of rotation (for example left bound) around the longitudinal axis of the wrapping. The two counter-rotating wrapping coils are applied with the bundle running in the same direction, without any rotation of the same bundle. This leads to the two coils having the same wounding spiral angle, with respect to the same longitudinal axis of the bundle.
This process preferably occurs continuously, on a continuous array of containers, with a final severing operation of the individual bundles, for example as described in WO2015040565 in the name of the same Applicant.
A wrapping of plastic film oblique with respect to the longitudinal axis of the bundle thus arises, with inclined layers superimposed in an oblique manner in the two opposite winding directions.
The two counter-rotating winding coils preferably have an angle ranging between 60° and 80°, with respect to the longitudinal axis of the wrapping. Experimental tests with 6-bottle bundles have highlighted that the ideal angle is in the range of 68-70°.
That is perceivable in fig. 1, in which the oblique attitude of the coils is shown on plastic material webs through dotted lines in the upper part of the bundle, where the plastic film runs above the upper ends of bottles B and creates a longitudinal depression between the three rows of bottles and two crosswise depressions between the three lines of bottles. The depressions are caused by the elastic tension with which the coils of stretching plastic film are applied onto the bottles, which tension is also the agent of the wrapping package consolidation and stability.
In order to obtain the best result, in terms of saving of material, but also of bundle stability, avoiding an excessive residual elasticity which would make the bundle unmanageable, preferably the stretching plastic film has a stretching rate in the range of 15-18%, but nevertheless maximum in the order of 20%.
According to the invention, on the wrapping package thus formed, two crosswise cuts I₁ and I₂ are practised, substantially in the area of the two depressions present between the three rows of the containers (see fig. 2).
These crosswise cuts cause a release of the elastic tension located in the crosswise depressions, which leads to a natural crosswise opening of the cuts (as seen in fig. 2), but does not allow the linear propagation of the cuts towards the sides of the bundle. In fact, the oblique attitude of the two counter-rotating webs of plastic stretching film causes a tension of the material which prevents the propagation of the cuts and invokes instead material in the areas of crosswise connection between the pairs of bottles of the two rows, in particular between the two central bottles adjacent to both cuts. Due to the angle of the counter-rotating webs of stretching plastic film, any stress applied cross-wise the bundle (i.e. perpendicularly to its longitudinal axis) doesn't cause any undesired propagation of the cuts, but a displacement of the material which enhance the local resistance of the wrap around the central bottles.
Indeed, the plastic film edges, caused by cuts, tend to curl toward the central bottles, without concentrating any stress in the corner of the cuts. That also causes a rope effect between the two central bottles, that is, the forming of a central band F, richer of material curled onto itself, which hence shows a greater rigidity and resistance to traction.
The central band, narrowed in the form of a wide cordon/rope, defines an ideal centre of gravity element for grabbing the bundle. Therefore, as shown in fig. 3, at the time when a buyer wants to lift the bundle, he/she inserts his/her fingers into one or both cuts I₁ and I₂, and then grabs centrally the band F which thus makes up a handle-shaped gripping element.
Due to the curling of edges, the band F has a suitable volume to be pleasant to be kept by hands.
This handle is sufficiently resistant to be able to be grabbed by a hand, in the way shown, and hence to allow, by applying an upward traction, to lift the entire bundle without fearing tears nor unpleasant elongations.
As can be understood, the solution offered here perfectly achieve the objects set forth in the preliminary remarks. As a matter of fact, through a simple wrapping of suitably shaped and cut stretching plastic film, it is possible to obtain a bundle package provided with a valid gripping handle, which is extremely effective, comfortable, light and inexpensive (both as material, and as manufacturing) .
However, it is understood that the invention must not be considered limited to the special arrangement illustrated above, which makes up only an exemplifying embodiment thereof, but that different variants are possible, all within the reach of a person skilled in the field, without departing from the scope of protection of the invention, as defined by the following claims.
For example, although a 6-bottle has always been illustrated, it is understood that the number of bottles or of containers may also vary: however, it remains essential that the wrapping with plastic film be performed in the way set forth above, practising two slits across the barycentric area thereof, preferably immediately downstream of and immediately upstream of two opposite containers belonging to two different rows.

Claims

Wrapped bundle package for a group of containers (B) arranged in an array of rows and lines, in particular a group of drink bottles, consisting of a multiple-layer wrapping of plastic film (P) made of stretching plastic material applied by stretching around said containers (B),
characterised in that
said layers of plastic film (P) are in the form of at least one pair of counter-rotating coils arranged with an oblique angle ranging between 60° and 80°, with respect to a longitudinal wrapping axis of the bundle, and in that
in said wrapping two transversal cuts (I₁, I₂) are provided, on opposite sides of a row of containers (B) located in a centre of gravity area of the package, arranged so as to release elastic tension in the film (P) which allow a curling of plastic film (P) edges at least towards a central creasing band (F) acting as gripping handle.
Wrapped bundle package as in 1, wherein said transversal cuts (I₁, I₂) are practised in a depressed area of said wrapping, in the middle of four raised areas corresponding to the position of four of said containers (B) of the bundle.
Wrapped bundle package as in 1 or 2, wherein said oblique angle ranges between 68 and 70°.
Wrapped bundle as claimed in 1, 2 or 3, wherein said stretching plastic film (P) has a stretching rate not above 20%.
Wrapped bundle as in any one of the preceding claims, wherein said containers (B) are six bottles on two lines and three rows.