Method and installation for producing a pack of grouped products, with integrated handle

Abstract

The invention relates to a method for obtaining a pack of grouped products (2) with a heat-shrinkable packaging having a reinforcing strip (3) for producing a handle, the method comprising: - unwinding a web (4) of a heat-shrinkable film towards a film wrapping machine inside which the products (2) to be packaged are conveyed; - cutting, in a longitudinal direction of the web (4), an end strip (3) with a width of between 30 and 90 mm, then placing the cut strip (3) on top and in the centre of the remaining portion of the web (4) in order to form a web (4) provided with a reinforcing strip (3); - packaging the products (2) with the web (4) provided with the reinforcing strip (3), and shrinking the whole to form the grouped pack.

Description

Description Title of the invention: METHOD AND INSTALLATION FOR PRODUCING A PRODUCT GROUPING PACK, WITH INTEGRATED HANDLE Technical field

[0001] The present invention relates to the technical field of heat-shrinkable packaging, in particular used to produce grouping packs, for example, of bottles sold in batches.

[0002] More particularly, the invention relates to a method, an installation and a reel of heat-shrinkable film for producing such a grouping pack incorporating a handle to facilitate its transport. Prior art

[0003] Known in the state of the art is an installation for producing a product grouping pack comprising a shrink-wrapper, i.e. a machine designed to group several products, such as bottles, into a single pack using heat-shrinkable plastic film.

[0004] To facilitate handling of the completed group pack, it is also known to create handles on the packs. These handles can be formed directly into the plastic film during the packaging process or added as add-ons.

[0005] For example, before packaging, the film can be pre-cut or perforated to form a handle. This method is not optimal because the strength of such a handle is questionable.

[0006] Alternatively, special machines can be used to apply prefabricated handles made of reinforced plastic or flexible composite to the film, before or after the shrinking process. These handles can be glued, welded, or mechanically attached to the film.

[0007] This type of handle can be sufficiently strong, but their integration is complex and expensive. On the other hand, the materials usually used to form such handles must be recycled separately from the wrapping film; when it is possible to recycle them (hot melt glues, etc.).

[0008] Document US 2021 / 347513 illustrates the state of the art by describing a method and an installation for obtaining a product grouping pack with heat-shrinkable packaging. Statement of the invention

[0009] One of the aims of the invention is therefore to overcome the drawbacks of the prior art by proposing a method, an installation and a reel of heat-shrinkable film, for example made of polyethylene, for producing a grouping pack incorporating a handle to facilitate its transport, the strength of the handle of which is optimal, and the complexity and manufacturing costs of which are reduced.

[0010] For this purpose, a remarkable process has been developed which consists of: - unrolling a strip of heat-shrinkable film towards a shrink-wrapping machine inside which the products to be packaged are conveyed; - cutting in a longitudinal direction of the width an end strip with a width between 30 and 90 mm, preferably between 50 and 70 mm, then superimposing the cut strip in the center of the remaining part of the width, above or below, in order to form a width equipped with a reinforcing strip; - to pack the products with the width equipped with the reinforcement strip and to shrink the whole thing to form the grouping pack.

[0011] In this way, the present invention makes it possible to produce a pack for grouping products, in particular those wrapped in heat-shrinkable film, with a directly integrated reinforcing strip allowing the pack to be subsequently gripped by an end user, without requiring the addition of an attached handle.

[0012] The process according to the invention is therefore simple, inexpensive and consumes less material. Furthermore, the recyclability of the packaging is improved because the handle comes directly from the packaging film itself.

[0013] Preferably, the method comprises a step of electrically charging the cut strip and / or band before superimposing the band on the remaining strip to promote the maintenance of said strip in the center of the strip.

[0014] In order to facilitate subsequent access to the handle formed by the reinforcing strip, the method preferably comprises a step consisting of creating weakening lines, in particular with perforations or pre-cuts. These weakenings are created on the film width at an area located on the top of the grouping pack and on either side of the reinforcing strip.

[0015] This way, when transporting the grouping pack, the end user can easily break the weakening lines to gain access to the reinforcement strip which acts as a handle to lift the pack.

[0016] Advantageously, a coating limiting the shrinkage of the film is applied to the film, centered on the weakening lines.

[0017] The installation according to the invention, which in particular allows the implementation of the aforementioned method, comprises a shrink wrapper, well known to those skilled in the art. This shrink wrapper implicitly comprises a conveyor for moving the products to be packaged within said shrink wrapper, a device for wrapping the film around the products, a shrink tunnel, etc.

[0018] The installation also comprises means for unwinding a reel of heat-shrinkable film, means for cutting an end strip in a longitudinal direction of the width of the heat-shrinkable film, and means for returning the cut strip superimposed on the central part of the remaining width.

[0019] This installation makes it possible to implement the aforementioned process in a simple and inexpensive manner, with the aim of obtaining a product grouping pack incorporating a reinforcing strip acting as a handle.

[0020] According to a particular simple and economical embodiment, the return means are at least two successive return bars inclined at 45° relative to the remaining width.

[0021] Preferably, the installation comprises means for electrically charging the strip and / or the central part of the remaining width, positioned upstream of the return means. These means are, for example, electrostatic induction.

[0022] The invention also relates to a heat-shrinkable film reel suitable for use in the aforementioned installation. The reel is remarkable in that it comprises at least one end strip with a width of between 30 and 90 mm, preferably between 50 and 70 mm, coated with an anti-slip layer between the end strip and the film. The anti-slip layer is for example in the form of a varnish which is coated on the film in order to obtain a coefficient of friction greater than 0.5.

[0023] Preferably, the film comprises pairs of weakening lines, for example of the perforation or pre-cut type, made along and in the center of the uncoated part of the strip, and at regular intervals separated by a distance corresponding to the length of film required for a bundling operation. The lines of a pair are spaced apart from each other and in width by a distance corresponding at least to the width of the coated strip. These weakening lines are intended to be broken to allow access to the handle after obtaining the grouping pack.

[0024] Advantageously, the film includes a coating limiting the shrinkage of the film, centered on the weakening lines, and over a width of between 15 and 30 mm, so as to prevent shrinkage when passing through the shrink tunnel.

[0025] According to a particular embodiment, the coated strip is printed according to a pattern repeated at regular intervals separated by a distance corresponding to the length of film necessary for a bundling operation, in order to be able to visually identify the handle on the resulting grouping pack. Brief description of the drawings

[0026] Other advantages and characteristics will emerge more clearly from the description which follows, given as a non-limiting example of the invention, from the appended drawings in which:

[0027] [Fig. 1] is a schematic side view of an installation for obtaining a product grouping pack according to the present invention.

[0028] [Fig. 2] schematically illustrates the module for cutting the end strip intended to act as a handle, and for returning said cut strip. Detailed description of the invention

[0029] With reference to Figures 1 and 2, the invention relates to a method and an installation (1) making it possible, in a conventional method of bundling a heat-shrinkable film around a grouping of products (2), to cut an end strip (3) in a longitudinal direction of the width (4) of the film, then to transfer it to the central part of the remaining width (5) of film before the product is packaged by the bundler (6), in order to form a directly integrated handle.

[0030] In a known manner, the products (2) to be packaged, for example bottles, are first conveyed to the shrink-wrapper (6) via a conveyor (7). A guidance system correctly aligns and positions the bottles according to the desired configuration of the pack (for example, 2x3 for six bottles).

[0031] In a known manner, one or more rolls (8) of heat-shrinkable plastic film are installed on the machine. The film is unwound conventionally by means of known unwinding means, and is cut transversely to the size necessary to wrap the preformed group of bottles.

[0032] According to the invention, and before the film is introduced into the shrink-wrapper (6), the strip (3) is cut, for example using cutting means (9), such as a blade, positioned, for example, at a return roller of the heat-shrinkable film. The width of the cut strip (3) is between 30 and 90 mm, preferably between 50 mm and 70 mm, for example 60 mm.

[0033] With reference to figure 2, the cut strip (3) is then folded a first time at 90° in one direction towards the inside, then a second time at 90° in the opposite direction to overlap the remaining width (5) in the center.

[0034] This step is carried out for example by two successive return bars (10) inclined at 45° relative to the direction of travel of the width (4).

[0035] In order to limit the movement of the strip (3) over the remaining width (5), the installation preferably incorporates means (11) for electrically charging the strip (3) and / or the central part of the remaining width (5), positioned upstream of the return means (10) in order to press said strip (3) against the remaining width (5) and ensure that it is held until the film retraction operation.

[0036] The remaining width (5) and superimposed strip (3) assembly is then introduced into the shrink-wrapper (6) where it is used to package the group of products (2), in a conventional manner.

[0037] Once the pack is wrapped in the film equipped with the reinforcing strip (3), it is conveyed into a heated shrink tunnel (12). The heat causes the film to shrink, tightening it around the bottles, thus forming a compact and stable pack.

[0038] At the exit of the tunnel, the pack is often subjected to a flow of cold air, for example by fans (13) to accelerate the stabilization of the shrunk film and ensure the cohesion of the pack.

[0039] The bottle pack thus formed is then evacuated from the shrink wrapper (6) by the conveyor (7), ready for the next stage of packaging or distribution.

[0040] The superimposed strip (3) allows for the creation of a reinforcement that can be used as a handling handle, directly integrated.

[0041] The invention uses the packaging film itself to create the handle, reducing waste and additional material costs. A single roll of shrink film is sufficient. The handle created in this way is aesthetically integrated into the pack, providing a uniform and neat appearance.

[0042] The method may comprise a step of creating weakening lines, such as perforations or pre-cuts, on the remaining width (5) of film at an area located on the top of the grouping pack and on either side of the reinforcing strip (3) to facilitate subsequent access to the reinforcing strip (3) as a handle.

[0043] According to different embodiments, these weakening lines can be produced upstream during the unwinding of the film, in the shrink wrapper (6), or preferably at the exit of the shrink tunnel.

[0044] Advantageously, a coating limiting the shrinkage of the film is deposited beforehand at the location of these weakening lines so as to prevent shrinkage during passage through the shrink tunnel. This coating is deposited centrally on the weakening lines over a width of 15 to 30 mm. Over this width, the thickness of the deposit is progressive so as to prevent breakage of the film along the coating when it shrinks.

[0045] The invention also relates to the heat-shrinkable film reel used in the installation (1). According to the invention, this reel is specifically adapted to the needs of the process.

[0046] The reel comprises for example an end strip (3) with a width of between 30 and 90 mm, preferably between 50 and 70 mm, for example 60 mm, coated with an anti-slip layer to prevent slippage between the end strip (3) and the remaining width (5) of film when the strip (3) is superimposed on the film. It is this coated strip which will be cut to form the handle.

[0047] The film of the reel may directly comprise pairs of weakening lines made along and in the center of the part of the uncoated width, and at regular intervals and separated by a distance corresponding to the length of film necessary for a bundling operation. The lines of a pair are spaced from each other, and in the width of the film, by a distance corresponding at least to the width of the coated strip (3).

[0048] At the level of the pairs of weakening lines, a coating limiting the film shrinkage is deposited centered on the weakening lines in order to prevent shrinkage during passage through the shrink tunnel. This coating is deposited over a width of 15 to 30 mm. Over this width, the thickness of the deposit is progressive in order to prevent breakage of the film along the coating during shrinkage.

[0049] The coated strip (3) may also be pre-printed in a pattern repeated at regular intervals and separated by a distance corresponding to the length of film required for a bundling operation in order to produce a visual marker for identifying the handle.

[0050] It is clear from the above that the invention provides a method, an installation and a reel of heat-shrinkable film for producing a grouping pack incorporating a handle to facilitate its transport, the strength of the handle of which is optimal, and the complexity and manufacturing costs of which are reduced.

Claims

Claims [Claims 1] Method for obtaining a product grouping pack (2) with heat-shrinkable packaging having a reinforcing strip (3) allowing the production of a handle, characterized in that it consists of: - unrolling a strip (4) of heat-shrinkable film towards a shrink-wrapping machine inside which the products (2) to be packaged are conveyed; - cutting in a longitudinal direction of the width (4) an end strip (3) with a width of between 30 and 90 mm, then superimposing the cut strip (3) in the center of the remaining part (5) of the width (4) in order to form a width equipped with a reinforcing strip (3); - to pack the products (2) with the width (4) equipped with the reinforcing strip (3) and to shrink the assembly to form the grouping pack. [Claims 2] Method according to claim 1, characterized in that it comprises a step consisting of electrically charging the strip (4) and / or the band (3) before superimposing the band (3) on the remaining strip (5). [Claims 3] Method according to one of the preceding claims, characterized in that it comprises a step consisting of creating weakening lines on the width (4) of film at an area located on the top of the grouping pack and on either side of the reinforcing strip (3) to facilitate subsequent access to the reinforcing strip (3) as a handle. [Claims 4] Installation (1) for obtaining a product grouping pack (2) with heat-shrinkable packaging having a reinforcing strip (3) allowing the production of a handle, characterized in that it comprises: - a shrink-wrapping machine (6); - means for unwinding a reel of heat-shrinkable film; - cutting means (9) of an end strip (3) in a longitudinal direction of the width (4) of the heat-shrinkable film; - means for returning the cut strip (3) superimposed on the central part of the remaining width (5). [Claims 5] Installation (1) according to claim 4, characterized in that the return means are at least two successive return bars (10) inclined at 45° relative to the remaining width (5). [Claims 6] Installation (1) according to one of claims 4 to 5, characterized in that it comprises means (11) for electrically charging the strip (3) and / or the central part of the remaining width (5), positioned upstream of the return means (10). [Claims 7] Installation (1) according to one of claims 4 to 6, characterized in that it comprises a reel of heat-shrinkable film comprising at least one end strip (3) with a width of between 30 and 90 mm coated with an anti-slip layer. [Claims 8] Installation (1) according to claim 7, characterized in that the film comprises pairs of weakening lines produced along and in the center of the part of the uncoated strip (4), and at regular intervals separated by a distance corresponding to the length of film necessary for a bundling operation, the lines of a pair being separated from each other and in width by a distance corresponding at least to the width of the coated strip (3). [Claims 9] Installation (1) according to one of claims 7 to 8, characterized in that the film comprises a coating limiting the shrinkage of the film, centered on the weakening lines, and over a width of between 15 and 30 mm. [Claims 10] Installation (1) according to one of claims 7 to 9, characterized in that the coated strip (3) is printed according to a pattern repeated at regular intervals separated by a distance corresponding to the length of film necessary for a bundling operation.