SK5072001A3 - Packaging wrapper - Google Patents

Abstract

The confectionery packaging has a separable film with detachable sections (20) to enclose the article (34). At least rear face of a film section is coated for cold sealing (22) at least partially around the periphery of the film. The larger parts of the sealed zones are superposed after folding to mutually adhere.

Description

container

Technical field

The invention relates to a package suitable for packaging articles comprising a packaging film which is divided into separate sheets intended to be folded over a wrapped article.

Without limiting the field of use, the invention relates in particular to the packaging of confectionery and chocolate products or other food products such as soup cubes.

BACKGROUND OF THE INVENTION

The products are generally individually wrapped in a rectangular sheet of preprinted packaging film of a suitable size and shape, wherein the individually wrapped articles can in turn be freely placed in a packaging bag of a suitable size. For example, a packaged product having the shape of a parallelepiped is placed in the middle of the backside according to a conventional packaging method, i. the unprinted side of the rectangular wrapping sheet. The two longitudinal sides are then bent vertically upward (or downward, depending on the location of the product and the type of packaging machine) around the two longitudinal sides of the product. Thereafter, the lateral sides are folded vertically around both sides of the article and their upper edges folded flat around the upper surface of the article, the latter two operations necessarily being performed by successive and oblique bending, with the forwardly bent longitudinal sides. The wrapping is completed by folding the upper edges (which in the meantime become trapezoidal flaps) of the longitudinal sides over each other, around the top surface of the article.

However, it should be noted that, depending on the shape of the packaged product and the type of packaging machine, a different sequence of folding film wrapping operations is possible, where this sequence of folding operations is performed according to well-defined fold line arrangements. This arrangement of the folding lines of the packaging film always remains the same for the same product packaged in the same packaging manner.

An important problem that arises here is the maintenance of the bends after the wrapping to keep the package closed. This maintenance of folds can only be ensured at the cost of a special selection of the film used as the substrate, which must have suitable mechanical properties such as flexibility and, in particular, a strong tendency not to return to its initial position after bending the wrapping film sheet during packaging.

This problem is particularly evident when packaging small products such as confectionery products, such as candies, pralines, lollipops, candy, chocolate coated bars, etc. or soup cubes.

A known solution is to select a substrate particularly known for its flexibility, such as paraffin paper, cellophane, aluminum laminates, or even synthetic films, containing a suitable amount of additives that increase the flexibility of the substrate.

However, this solution greatly limits the choice of film used as the backing for the packaging or significantly increases the cost.

Also known are packaging foils for various products, such as soup cubes, where the sealing of the package is secured by gluing. For this purpose, the foil from the front tents, i. from the outside of the packaged product, a heat-sealing layer, the arrangement being adapted to the arrangement of folds formed in the package.

This packaging method has the disadvantage that the packaging machine must be specially adapted to this method to the extent that a heat source is required. In addition, if the heat source is formed by heating plates, gluing can only take place on perfectly planar surfaces of the packaged product, requiring, in addition to the time required for welding, a relatively significant pressure which cannot withstand a certain number of products.

A further disadvantage is that this packaging method is completely unsuitable for packaging heat-sensitive products, in particular chocolate products, and does not allow the selection of a substrate for packaging that has poor temperature resistance.

Patent application EP-0 870 695 proposes a packaging film intended to be closed around a product, the front side of which, i.e. the side located outside the article has a cold adhesive layer disposed in such an arrangement that these adhesive areas overlap by folding the wrapping film around the article. These adhesive areas therefore ensure the maintenance of bends when the wrapping film material has such a property that it does not maintain these bends. However, the wrapping film is provided with a hot-melt coating which keeps the wrapping film closed and which has the disadvantages mentioned above. This wrapping film also has the further disadvantage that the back side must contain anti-adhesive strips to allow the film to unwind from the reel.

EP-0 225 987 discloses a packaging film having, on the front and on the back, adhesive regions for cold gluing, namely two longitudinal strips on the front and on the back, respectively. In order to be able to make this film in a form wound on a reel, these different adhesive areas must be positioned so that they do not overlap during winding. Such an overlap would in fact cause these different regions to stick together and prevent the foil from unwinding from the reel. However, this restriction, as far as the location of the adhesive areas is concerned, includes a restriction corresponding to the arrangement of the bends and the manner of packaging.

In fact, the above-mentioned documents pursue the same objectives, namely to apply adhesive areas to the film to maintain the folds and to provide a film treatment in the condition wound on the reel. The problem is that, as described below, if the film includes two self-adhesive regions on the back and front when it is wound on a coil, there is a risk that some of these adhesive regions of two adjacent windings overlap on the coil and stick together which would prevent the foil from unwinding from the spool.

The two writings attempt to solve this problem by various means. EP-0 870 695 envisages the use of cold-adhesive areas only on the front. Therefore, there is no danger of overlapping each other during winding. On the other hand, in order to solve the problem of keeping bends, this document envisages a hot-melt coating on the back, which leads to the aforementioned disadvantages.

EP-0 225 987 discloses a special arrangement of the cold back adhesive layer with respect to the layers on the front side and vice versa, so that during winding the two adjacent windings are arranged side by side and no overlap occurs. However, this solution limits the packaging method in that it is necessary to determine the bending arrangement according to the location of the adhesive areas, although this is the opposite of what is required.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a new package which allows to significantly extend the selection of the film used and which makes it possible to convert the film into a reel without any restriction as to the packaging method.

In order to achieve this goal, a package according to claim 1 is provided according to the invention.

Surprisingly, the Applicant has found that pre-coating, at least partially, the foil used as a wrapper with a precisely defined cold-bonding layer allows to obtain bends showing excellent bending to close the wrapping film by bending, while allowing the film to be wound on the reel.

This fact, that the substance used as an adhesive layer, shows little or no adhesion to a smooth surface or to a surface prepared for this purpose, but, on the other hand, exhibits good adhesion when applied to itself, as is the case with bending. Maintaining the bends is simply ensured by lightly squeezing and overlapping certain areas of the adhesive layers with one another, and this is accomplished without additional accessories such as those required to bend the package.

The term cold bonding according to the present invention refers to bonding which occurs immediately, by simple contact, at a temperature of about 0 to 50 ° C. In fact, temperature is not a critical parameter in achieving bonding by means of a cold bonding adhesive layer and has virtually no effect on the quality of the bonded joint obtained. Thus, the bonding can be achieved without any additional heat supply, at the ambient temperature of the environment in which the packaging unit is located.

In fact, to date, adhesive layers have been used for cold bonding, in particular for layers on a substrate that are not subject to deformation or are only subject to slight deformation. In fact, considerable blocking problems can be expected due to the self-adhesive properties of the cold adhesive adhesive layer in all applications of the cold adhesive adhesive layer to the non-planar substrate.

Thus, the present invention allows for the use of cheaper films and exhibits better properties (stiffness, suppression capability, aesthetic appearance) for packaging products without limitation as to the shape of the products.

With regard to the use of rigid films, it should be noted that until now rigid films have not been used for packaging which must be closed by bending. Indeed, these films have a very low bending ability.

As regards the problem of treating the coil winding film, in comparison with the solutions in the two prior art documents, this application creates a completely different solution, which has been impossible to achieve so far, which consists in tolerating the overlapping of the different adhesive areas with each other. foil adapted to be wound on a spool. To this end, the invention provides a selection of a well-defined cold-bonding adhesive layer which is as defined in the term "controlled adhesion", i. Adhesion strong enough to meet the needs of the case but not sufficient to prevent repeated peeling. Thus, the foil can be unwound several times from the receiving reel, without excessive resistance, even from the inner winding, where the compression is normally higher. Of course, this solution represents significant advantages over the solutions suggested in the foregoing documents, within the limits where the same adhesive can be provided everywhere (i.e. more than for hot bonding) and where adhesive areas can be secured at the desired locations depending on the shape the packaged product and the bending sequence.

According to a preferred embodiment, the backing structure of the adhesive layer comprises two W-shaped strip structures along two opposite sides of the packaging film, one strip along the third side of the packaging film and between the two W-shaped strip structures and two areas in the two corners of the fourth side of the packaging film.

The strips with an adhesive layer positioned according to the bending arrangement may have a width of about 4 mm.

The structure of the adhesive strips may have different shapes depending on the packaged product and the bending sequence.

In addition to the strip structure along the folds being made, each sheet of packaging film may comprise a strip with an adhesive layer along the edge of the third side. This strip is located on the flap that at the end of the packaging method will be folded first to the base of the packaged product and will provide a bond with the flap that will be folded last. In addition, each sheet of packaging film may include additional adhesive areas to allow the flap to be glued last to the base of the packaged product, and may thus contribute to maintaining the closure state of the package.

According to one aspect of the present invention, the adhesion achieved by overlapping the strips with the adhesive layer for cold bonding is not irreversible, since it must allow the film to be unwound when the film is treated and deposited on the reel without the risk of tearing it. In other words, it is necessary to select an adhesive layer depending on the type of substrate to which it is applied, on the one hand its own adhesion to itself is sufficiently weak to allow the packaging foil to unwind from the reel and, on the other hand, strong enough to ensure quasi-hermetic sealing. Thus, controlled adhesion can be said. This controlled adhesion has, inter alia, the advantage that it is possible to open and close the package several times without noticeably reducing the quality of this adhesion.

As mentioned above, one of the advantages of the present invention is that it allows the use of a wide range of options as to the type of substrate used. Examples of suitable substrates are plastic films of about 10 to 100 microns thick, of extruded and oriented polypropylene, of polypropylene in the form of a cast film, of polyester, of polyethylene, of extruded and oriented polyamide, or of polyamide or polyamide in the form of a cast film.

According to the present invention, it is also possible to use a paper substrate (smoothed or coated). Generally speaking, any backing material or any flexible wrapping material may be suitable as a backing according to the present invention. These different substrates may consist of a single layer, a single metallized layer, or multiple layered layers and / or coextruded layers.

Generally speaking, pressure-sensitive adhesives are compounds based on natural and / or synthetic rubber, coupled with treated cellophane, phenol-formaldehyde resins, or hydrocarbon resins (waxes). In addition to rubbers, polymers based on styrene, (meth) acrylic acid or vinyl ethers, alone or in admixture, as well as in combination with resins, are widely used. In particular, compounds containing mixtures of natural and synthetic rubber and copolymers of (meth) acrylic acid and styrene are used.

According to the present invention, the cold adhesive layers are applied to the substrates in an amount of about 1 to 5 g / m ² . The cold adhesive layers may be applied in the form of a solution, dispersion or even in the molten state.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and features of the invention will be apparent from the following detailed description of several preferred embodiments, with reference to the accompanying drawings, in which: FIG. 1 shows the front side of one embodiment of a wrapping sheet, FIG. 2 to 8 show a sequential sequence of the candy wrapping operation of the wrapping film sheet of FIG. 1, FIG. 10 shows the front side of the embodiment of FIG. 1, supplemented with an adhesive structure on the back, FIG. 11 is an enlarged scale and cross-sectional view of the embodiment of FIG. 10 and FIG. 12 shows a simplified variant of the embodiment of FIG. 10th

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, the front side or the printed side of the wrapping film sheet 20, after being cut from the foil unwound from the storage coil (not shown), is shown in the direction shown by the arrow A.

The cold-adhesive adhesive layer is disposed in a structure 22 which is adapted to the configuration of the fold lines formed in the package, an example of which will be described below. In the case of FIG. 1, there are two webs of strips 24 and 26, about + 4 mm wide, approximately W-shaped, along opposite sides of the wrapping sheet 20, and a strip 28 along the third side of the wrapping sheet 20, between two side-shaped structures " W. On the opposite side of the strip 28 there are also two cold-gluing areas 30 and 32 in the corner region. With respect to the film originally deposited on the reel, the strips 24 and 26 are positioned along the longitudinal edges, while the strip 28 is disposed transversely. On the coil, these different adhesive-coated strips on the front are located on the outside of the various coil windings.

The packaging film sheet 20 of FIG. 1 can be made by depositing a thin printing layer or primer (e.g., SIEGWERCK 10-612205-4 MX41) to improve ink adhesion to the front side of a 25 micron oriented polypropylene film, metallized or unmetallised. The coating is applied by a printing technique known per se, for example by heliographic or flexographic technique, or by offset printing. A protective lacquer, which is also known per se, is also applied for printing. Cold lacquer structures 22 are applied to the lacquer according to the pattern shown in FIG. 1. This deposition can also be performed by printing techniques known per se.

For cold bonding, SWALE IP7905 or IP7936 can be used in an amount of, for example, 3 µ / ιτΛ. This is an adhesive layer that adheres only to itself. In other words, this layer does not adhere to the untreated smooth back side of the film, allowing the film to be simply laid and trimmed on the reel without any unwinding problem. This adhesive layer is of such a quality that it has a low coefficient of friction (COF) on the metal which is in the range of 0.2 to 0.6, whereas this coefficient of friction (COF) on the metal is normally in the range of 1 to 1 , fifth This low coefficient of friction reduces the risk of creasing and grip on the bent box.

According to FIG. 2 to 8, a substantially parallelepiped candy wrapping operation in the wrapping film sheet 20 of FIG. 1. This sheet 20 is placed on the candy 34 with its back or untreated side facing the candy 34 so that the strip 28 and the opposite side with the adhesive areas 30 and 32 are positioned in the longitudinal direction of the candy 21, ^{and the} W-shaped structures. The sides of the wrapping film sheet 20 are then bent down over the longitudinal walls of the candy 34, as shown in FIG. Second

In a subsequent operation, the central region of each side of the wrapping film sheet 20, with the structures 24 and 26 on the side walls of the candy 34, is bent as shown in FIG. 3. This operation is performed by bending with longitudinal sides 20 sheet packaging film pursuing oblique folding lines 36 and 38. As ^e j Referring to FIGS. 3, both the W-shaped structures 24 and 26 (where the structure 26 is not visible in FIG. 3) with the adhesive layer are positioned such that the two outer members of the W-shaped structures extend along the fold lines 36, and 38, and that the V-shaped inner portion is placed on the side of the candy 34.

In the following operation, two sides of the film 34, defined by the fold lines 36 and 38, are bent inwardly in the direction of the arrows 1 and 2 in FIG. 3. By this operation, the outer strips of the structures with an adhesive layer in the form of the letter "W", i.e. these strips extend along the fold lines 36 and 38 on the inner strips in the "V" shape, and as a result, the arrangement shown in FIG. 4. It is clear that this bending sequence takes place on both sides of the candy 34. Assuming that the letter-like structures 24 and 26 overlap and that the cold adhesive used adheres perfectly to itself, the arrangement of FIG. 4 is a stable configuration with perfect maintenance of bends hitherto performed.

all the strips of both "W," are mutually complete

The following bending sequence is shown in FIG. 5 and bending the lower portions of the side walls which have been bent and folded in advance to the underside of the candy 34. This operation is performed by bending, with longitudinal sides following the oblique bending lines 60, 42, 44, 46 forming the longitudinal sides of the trapezoidal flaps 48, 50. The result of this bending sequence is clearly seen in FIG. 6, showing a bottom and side view obscured in the preceding figures.

It should be noted here that the two cold adhesive regions 30 and 32 are positioned so that their oblique inner edges (see also FIG. 1) extend along the fold lines 48 and 42 of the flap 8 as shown in FIG. . 6th

Fig. 7 and 8 show the last stage of packaging. First, the flap 50 provided with the adhesive layer strip 28 is folded over the inner side, as shown in FIG. 7. The second flap 48 is then folded over the flap 50 to form the arrangement of FIG. 8th

When the flap 48 folds, the two adhesive regions 30 and 32 are partially overlapped to each other, and are applied to the strip 28 with the adhesive layer of the flap 50. As a result, assuming the flap 48 adheres to itself and the flap 50, Fig. 8 is a stable configuration with good maintenance of all bends.

However, it should be noted that when the flap 48 folds over the flap 5CD, the adhesive layer strip 28 only adheres to its adhesive areas 30 and 32, in contrast. Its central portion contacts the back of the flap £ 8 to which it adheres non-adherently. . In other words, if the packaging film sheet 20 of FIG. 1 provides a package with a stable and durable closure, does not provide a sealed package.

Each packing sequence described below is carried out automatically in a packaging machine. In this regard, it is important to note that the proposed packaging film sheets 20 are suitable for existing packaging machines, without the need for any modification or adaptation. It should be noted, however, that the package described below is only an example of the bending arrangement on the intended machine. On other machines, bending may be performed according to different bending line arrangements. In this case, it would be appropriate to adapt the pattern of adhesive structures shown in FIG. 1, to arrange the bending lines performed by the bending machine, the reverse procedure being more difficult.

In FIG. 10, a preferred embodiment of a packaging film sheet 56 according to the present invention is shown.

It is possible that the foil of oriented polypropylene can be used again, suitably printed, possibly after application of the coating material. An anti-adhesive layer 60 is then applied to the entire front surface. Suitable anti-adhesive products consist of a mixture of polyamide resin and polyethylene wax (e.g. SIEGWERCK products 10-609345-3P and SICPA 994404-X) applied at 1.5 g / m ² . A pattern of the cold-bonding adhesive structure 22 is then applied to this layer, as in FIG. 1. A cold-bonding adhesive strip 58 is then applied to the back, approximately between the front side regions 30 and 32, as shown in FIG. 10 dashed line. When the packaging foil sheet 56 is used for the packaging described in FIG. 2 to 8, the adhesive layer strip 58 will be positioned, at the end of the packaging operation (see FIG. 7) on the inside of the flap 48, and after folding it adheres to the flap adhesive strip 28, to form a quasi-hermetic package.

When the film according to FIG. 10 mounted on the spool, the adhesive layer strips 48 are generally in contact with the anti-adhesive layer 60 on the back side, on the back side to which they do not adhere. However, the adhesive-coated strips 58, however, also come into contact with the adhesive-coated strips 28 during unwinding and after a number of windings. In this case, by selecting the type of adhesive for the strips 28 and 58 and its controlled adhesion, there is also the possibility of peeling and unwinding the film from the reel without advancing the film and without significantly reducing the adhesive properties of the strips 28 and 58.

Instead of providing the strips with an adhesive layer having a generally rectangular shape, as shown in the figures, oval-shaped strips may be used. This arrangement allows for gradual release with less risk of tearing when opening the package or unwinding the film from the reel.

In FIG. 11 is an enlarged scale and cross-sectional view showing the thickness of the packaging sheet 56 of FIG. 10. In this example of a preferred embodiment, different layers are formed, denoted by letters A to F, wherein layer A forms the front side and layer F the back side:

A: latex-based adhesive layer applied at 2 to 4 g / m ² , SWALE IP 7985,

B: PVB lacquer (polyvinyl butyne, product WO 48825 SWALE with wax additives and anti-adhesive properties for the coating of layer F and applied in an amount of 0.7 to 1.3 g / m ² ,

C: PVB color printing, Dynavin series from SWALE, applied at 2 to 3 g / m ² ,

D: Primer - aqueous solution, type 200970 from SWALE, applied at 0.4 to 0.8 g / m ² ,

E: oriented polypropylene film, co-extruded, type BEZ, from VIBAC, with a thickness of 30 µ and composed of:

E1: metallized layer with a thickness of 0,02 to 0,04 μ

E2: a co-extruded layer with a thickness of 1,5 μ, composed of a mixture of copolymers and homopolymers,

E3: 27 μm homopolymer cores,

E4: co-extruded layers of homopolymers with anti-adhesive properties for layer A.

F: Latex-based cold adhesive, 2 to 4 g / m ² , SWALE IP 7983.

The film thus formed can be unwound and wound up to ten times on and out of the spool without losing the adhesive properties necessary to form a sealed package.

In FIG. 12 shows a simplified variant of the embodiment of FIG. 10. In this variation, the wrapping film sheet 62 simply comprises, on the back, along the edges (transverse to the film wound on the spool, prior to cutting it), a cold adhesive layer strip 64 corresponding to strip 58 of FIG. 10, and at the opposite edge from the front side, another strip 66 with a cold adhesive layer corresponding to strip 28 of FIG. 10. The composition of the wrapping film sheet 62 may be as previously described in FIG. Both strips 64 and 66 have been shown for explanation, and as indicated before, are in an egg shape to facilitate release when unwinding from the spool.

In other words, in this variant of FIG. 10, the adhesive layer structure 24, 26, 22 '32 of FIG. 10. This variant can be used when a quasi-hermetic seal is not required, which is possible according to the embodiment of FIG. 10, and when closing along the fold lines is not sealed. In contrast, the last phase of the package, formed by the overlapping of the adhesive regions 64 and 66, allows the pre-formed folds to be maintained when the package is performed in a folded box machine, i. when all the bends shown in FIG. 3 to 6 are performed practically simultaneously.

Claims (4)

PATENT CLAIMS A package for wrapping a product (34), in particular a food product, obtained from a film wrapped in a longitudinal direction on a spool and divided transversely into separate sheets (56, 62) and intended to be closed by bending around the product (34), that the film comprises, on each sheet (56, 62), along each transverse edge, a strip (28), (58), (64), (66) with a cold-adhesive adhesive layer, wherein one strip (28), ( 66) is placed on the front and a second strip (58), (64) on the back of this sheet, overlapping these stripes (28), (58), (64), (66) to ensure final closure of the package after the last a bending sequence, and wherein the mutual adhesion between the strips (28), (58), (64), (66) is a controlled adhesion sufficient to maintain the closure of the package but not sufficient to interrupt the unwinding of the film from the spool, (66) on the front and strip (58), (64) on the rear in the wound state on the spool. Packaging according to claim 1, characterized in that the front side of each sheet comprises regions (22) of a cold-adhesive adhesive layer disposed at least partially along three sides at the edge of the sheet (56) in such an arrangement that most of these regions are overlapped after bending around the article, glued together to maintain bends around the article. Packaging according to claim 1 or 2, characterized in that the adhesive layer of the strips (58), (64) with the adhesive layer, is applied on the back in the form of an oval strip. Packaging according to claims 1 to 3, characterized in that each sheet (56, 62) comprises on the entire front antiadhesive layer (60), which is applied in front of the layer by a region of the adhesive layer for cold gluing.