EP0929467B2 - Packaging wrapper closed by twists - Google Patents

Abstract

PCT No. PCT/EP96/04378 Sec. 371 Date Nov. 26, 1997 Sec. 102(e) Date Nov. 26, 1997 PCT Filed Oct. 8, 1996 PCT Pub. No. WO97/24273 PCT Pub. Date Jul. 10, 1997The packaging wrapper consists of a film intended to be closed by at least one twist (22), including, on the internal side, a cold-sealing coating placed along two lengthwise strips (12, 14) on either side of the article to be packaged in order to retain the twists. The film additionally has at least one transverse additional strip (24), (26) of cold-sealing coating placed along one edge of the film (20) perpendicularly to the lengthwise strips (12, 14). The packaging process consists in closing the wrapper by virtue of the transverse strips (24), (26), along a direction parallel to the axis passing through the twists (22).

Description

The present invention relates to an envelope packaging for articles, said envelope being closed with at least one foil.

The invention also relates to the production in a package closed with foil.

In particular, the invention falls within the scope of the packaging of confectionery products.

Generally, confectionery products are individually wrapped in a piece of film preprinted in an appropriate size and shape, which individually wrapped products which can be tower be packaged in bulk in a packaging bag of an appropriate size. Typically, the article to be wrapped is first completely wrapped in a portion of rectangular film and the envelope thus formed is closed by twists at two points located on either side of the item to be packaged.

Note that these packages are not always closed by two twists. We can for example place the item to be wrapped in the center of a portion adequate film with flaps overhanging the article above said article before closing the envelope thus formed by stranding said sections into a single foil.

In the context of the present invention, by foil the result of the stranding closure of said envelope.

An important problem at this level is that of retaining the foil. This retention can only be obtained at the price of a particular selection of the film used as a substrate, which must have appropriate mechanical characteristics such as that pliability or, in particular, a pronounced tendency not to return to its original position after stranding of that film.

In particular, this problem manifests itself during packaging of small and section items substantially round such as confectionery such as candies, lollipops, barley sugars, fruit pastes, chocolate bars or even larger products like bottles, rolls of coins, ...

As a solution, it is known to select particular substrates known for their high foldability, like waxed paper or cellophane or even synthetic films containing an appropriate amount an additive increasing the pliability of said substrate.

This solution is obviously not satisfactory insofar as it considerably limits the possibilities of choice of films used as substrate packaging and to the extent that it increases considerably the cost.

We know on the closed packaging market by foils which are made from substrates previously coated with a sealer hot. When forming papillotes at the ends of the envelope containing the article to be wrapped, we approach for a certain amount of time a source of heat at a temperature between approximately 120 and 160 ° C., - generally, these are the jaws performing stranding which are heated but it's also possible to blow hot air through a tube of appropriate size - on said foils, which results in the melting of the sealant the sealing of the foil thus formed during the cooling of said heat seal coating.

This solution increases the choice of packaging substrate, but is not yet entirely satisfactory insofar as it does not allow not selecting a substrate with low resistance at high temperatures and, more seriously, it is totally unsuitable for packaging sensitive items heat, especially chocolate products. Another shortcoming of this solution is the relatively fast speed low that it imposes, it is, indeed, necessary keep the foils and the element in contact heating for sufficient time to achieve fusion sealing plaster.

It is generally considered that the packaging 800 items per minute is the highest rate that can be achieved with a working packaging unit according to the principle of closing the envelope by stranding and heat sealing the foil as well formed.

To avoid the inconvenience of hot and without being limited in the choice of films used, GB-A-1096058 provides a film with a coating cold sealing which, after closing the envelope by stranding foil, has excellent retention. This cold sealing coating is presented in the form of two longitudinal strips located in the zones of formation of the papillotes on the part and of the item to be packaged.

By cold sealing is meant a seal which takes place instantly by simple contact at a temperature between 0 and 50 ° C approximately. In reality, temperature is not a critical parameter as to obtaining a seal by means of a sealant cold and has practically no influence on the quality of the seal obtained. We therefore carry out the sealing without adding additional heat to the temperature ambient space in which is the packaging unit is not required.

In fact, cold seal coatings have, up to present, mainly used as a layer on a substrate with little or no deformation. We can expect significant blocking issues due with self-adhesive properties of the sealing plaster cold in any use of this sealant to cold on an uneven substrate.

The method described in the aforementioned document takes advantage of this feature to achieve retention papillote.

In addition, in the case of a selected foil by means of a cold sealing coating it is not necessary to apply pressure over the entire length papillote. However, this results in a seal uniform over the entire length of the foil thanks to the action of the torsional forces imparted during stranding of the envelope.

This method therefore allows the use of cheaper films with better properties (rigidity, propensity to print, aesthetic qualities) for packaging articles without restrictions on the shape or the sensitivity to heat of said articles.

As for the rates that it is possible to reach with a packaging unit operating according to the principle of closing the packaging by stranding and cold sealing of the foil thus formed, it is advisable note that the only limit on cadence is imposed by the machine itself. This packaging method thus allows to reach cadences of minus 1,500 items per minute.

The object of the present invention is to provide a new packaging of the cold sealing type of the foil which has all the known advantages of this type but which also allows closure almost airtight packaging.

In accordance with the invention, this object is achieved by a packaging envelope made of a film and intended to be closed by at least one foil comprising, on the inner side in relation to the article to be packaged, a cold sealing coating arranged in two parallel longitudinal strips on either side of the article to be packaged, characterized in that the film has at least one additional transverse plaster strip cold seal located along one edge of the film perpendicular to said longitudinal strips sealing compound so as to allow, after stranding the envelope, close it as follows a direction parallel to the axis passing through the two twists.

Thus, the packaging is closed almost hermetically, which is very advantageous in terms of conservation articles since it prevents the penetration of moisture, gas, air or other substances and at the same time time, keeps the aromas inside.

According to an advantageous embodiment, the film has two transverse strips of plaster cold sealing extending perpendicularly between the longitudinal strips along the opposite edges. In this way, when the article is placed on the film in view of the packaging, it is completely surrounded by bands cold sealing.

When preparing a roll of film for packaging one of the faces of which is coated with sealing plaster, preferably apply a non-stick coating at least partial of the film used, on the other side in order to avoid adhesion by contact between the coated side seal and the other side when winding. It suits however note that there are sealers cold so-called "dry" which, when used together with certain substrates such as films of polypropylene, do not require such a non-stick coating. These two methods can also be used in the context of the present invention.

All the non-stick coatings which are conventionally applied to the back of the face of the film which carries the strips of cold sealing coating can be used within the framework of the present invention. In particular, suitable non-stick coatings consist of mixtures of polyamide resins and polyethylene waxes (for example the products 10-609345-3p from the company SIEGWERK and 994404-x from the company SICPA). In general, these non-stick coatings are deposited on the substrate at a rate of 1 to 5 g / m ² .

According to a particularly embodiment advantageous, the portion of film coated with sealing plaster cold intended for the formation of the packaging envelope has areas coated with sealant cold from 1 to 50 mm wide located around the space reserved for the item to be packaged. By doing so, we avoid, if necessary, any contamination problem between the packaged item and the cold seal coating and, in in addition, there is a substantial saving of said coating sealing. However, we keep all retention property of foil packs since areas coated with cold sealing plaster have a appropriately, been arranged at the location of the film or said papillotes are formed.

We therefore preferably have the coating of cold sealing in a suitable pattern suitable for the article to pack.

As mentioned above, one of the interests of the cold sealing coating is that it allows the use of a wide range of possibilities regarding the nature of the substrate used. Examples of substrates suitable are plastic films of about 10 to 100 microns in extruded and oriented polypropylene, in polypropylene in the form of a cast film, in polyester, in polyethylene, in extruded and oriented polyamide or polyamide as a cast film.

In accordance with the present invention, can also use a paper substrate (rubbed or lying down). Generally, any support material or flexible packaging material may be suitable as a substrate for the present invention. These different substrates can consist of a single layer, a single metallic layer or in several layers laminated and / or coextruded.

The choice of cold sealing plaster does not present not critical. As a coating of cold sealing, we can consider sensitive adhesives to pressure which are substances that are sticky permanently and spontaneously joining on the surface of most materials under the effect of a simple moderate pressure.

In general, adhesives sensitive to pressure are rubber compositions natural and / or synthetic associated with cellophanes modified phenol-formaldehyde resins or hydrocarbon resins (waxes). Besides the rubbers, polymers based on styrene are widely used, (meth) acrylic acid or vinyl ether, alone or in mixture, also in combination with resins. Finally, it is also possible to use silicone resins. Preferably, compositions comprising mixtures of natural and synthetic rubbers and copolymers of (meth) acrylic acid and styrene.

In accordance with the present invention, the cold sealing coatings are deposited on the substrate at a rate of approximately 1 to 5 g / m ² .

Cold seal coatings can be applied as a solution, dispersion or even in the molten state.

It is also possible to deposit between and / or on either side of the strips of cold sealing plaster another plaster, for example inert or non-stick. As other coating, any coating compatible with the nature of the product to be packaged can be used. In general, these other coatings are also deposited on the substrate at a rate of approximately 1 to 5 g / m ² .

Films according to the present invention are prepared using plaster deposition techniques well known to those skilled in the art such as, for example, heliographic or flexographic printing or still offset printing.

• la Figure 1 montre un emballage connu du genre décrit dans le document GB-A-1096058 ;
• les Figures 2a, 2b et 2c représentent en section transversale les phases successives de l'emballage de l'article à l'aide d'un film selon la Figure 1 ;
• la Figure 4 est une vue en plan d'un film d'emballage selon la présente invention ;
• les Figures 5a, 5b, 5c et 5d sont les séquences successives d'emballage de l'article à l'aide d'un film selon la présente invention ;
• les Figures 6a, 6b et 6c représentent des vues en perspective des différentes séquences d'emballage de l'article avec le film selon la présente invention ;
• la Figure 7 représente l'article emballé après la formation des deux papillotes et
• les Figures 8 et 9 représentent le scellage et le pliage de l'emballage selon la présente invention dans la direction parallèle à l'axe passant par les papillotes.

The invention will be better understood on reading the description of some embodiments presented below, by way of illustration, with reference to the appended drawings in which:

• Figure 1 shows a known packaging of the kind described in GB-A-1096058;
• Figures 2a, 2b and 2c show in cross section the successive phases of the packaging of the article using a film according to Figure 1;
• Figure 4 is a plan view of a packaging film according to the present invention;
• Figures 5a, 5b, 5c and 5d are the successive sequences for packaging the article using a film according to the present invention;
• Figures 6a, 6b and 6c show perspective views of the different packaging sequences of the article with the film according to the present invention;
• Figure 7 shows the wrapped article after the formation of the two twists and
• Figures 8 and 9 show the sealing and folding of the package according to the present invention in the direction parallel to the axis passing through the foils.

Figure 1 shows an indicated film strip overall by the reference 10 which is coated with two longitudinal strips 12, 14 of a sealing coating to cold. The items to be packaged are shown in dotted lines by the reference 16. The film strip is intended to be cut along lines 18 to supply parts of 20 identical films which play the role of a packaging envelope for the articles 16. In the Figure 1, the silhouette has also been shown in dotted lines 22 foils obtained by stranding the projections on either side of the article to be packaged 16.

Figures 2 show the different sequences of a conventional packaging process, Figures 2 being sections along a plane perpendicular to the axis passing by the future papillotes.

The article to be packaged 16 is placed on a film 20 and the two sides with the cutting edges 18 of Figure 1 are raised vertically against article 16. Note that, in the example shown, article 16 is off center on film 20 so that one of the sides, in this case that indicated by A, is longer than pan B, as shown in Figure 2a. We fold then the shortest section B on article 16 (see Figure 2 b) and then pan A on article 16 and the edge of the pan B (see Figure 2c). We then strand the two ends exceeding article 16 by turning each in the direction of folding down of pan A to form the two twists 22.

Figure 4 shows a packaging film 30 according to the present invention. In this figure, we used the same reference numbers to designate the parties corresponding to that of Figure 1. As we can see it, this film 30 also has two strips longitudinal 12 and 14 cold sealing plaster. Consistent to the invention, the film also comprises transverse bands 24 and 26 extending along the cutting edges perpendicularly between the strips longitudinal 12 and 14 on either side of the spaces reserved for items to be packaged 16.

In use, the film 30 is cut from a roll, the cold sealing plaster structure 34 is finding on the inner side. The film 30 is then sectioned along the cutting lines 18 passing through the middle cross bands to form individual films 20.

The film 30 is particularly suitable for an advantageous packaging method proposed herein invention and explained in more detail later in reference to Figures 5 to 9. Article 16 is placed on a film 20 inside the sealing plaster frame cold and the two side panels are folded towards the top, as shown in Figures 5a and 6a. However, unlike the known process, article 16 is this time placed in the center of the film so that the two sides A and B are perfectly the same length. Then fold the two sides simultaneously on item 16 so that their inner edges with the transverse bands 24 and 26 are placed one against each other, as shown in Figure 5b. We then exercises, as shown in Figure 10, pressure on the outside of each of the edges of sides A and B over the entire width to seal well together these two sides at the level of their sealing plaster Cold. This operation of folding sides A and B and sealing their edges can be done in one operation between the jaws of a press 28 (Figure 5b). This gives a sealing rib 32 which spans the entire width, as shown Figures 5c and 6b. This rib is then folded and folded on the packaging according to Figures 5d and 6c, preferably, by exerting a vertical pressure according to the Figure 11 to give the packaging a presentation attractive. The packaging is completed by stranding the two ends in the direction of the folding of the rib 32 to form two twists.

Thanks to the presence of the transverse bands 24, 26 cold sealing plaster and thanks to the setting work of pressure, we obtain a perfect closure across the full width of the package. Longitudinal bands 12 and 14 also provide lateral sealing during the formation of the papillotes. We thus realize a almost hermetic packaging which prevents the exit of aromas or the penetration of air, humidity, harmful odors, etc.

The following examples illustrate the invention more without limiting it.

Example 1: a non-stick coating (10-609345-3p from the company SIEGWERK) is deposited on a white oriented polypropylene film 30 microns thick (1.5 g / m ²⁾ . Longitudinal strips of 15 mm width of cold sealing plaster (product 22-392 from the company CRODA) are deposited on the other side of the same film at a rate of 3 g / m ² spaced 40 mm apart and perpendicular to the longitudinal strips, between these strips, parallel strips of 15 mm width of cold sealing plaster (product 22-392 from the company CRODA) at a rate of 3 g / m ² , spaced 80 mm apart, with a length of 40 mm.

Example 2: use of the film for making packages closed with foils.

With the films of Example 1, we pack chocolate products (sizes, weights and shapes miscellaneous) with a wrapper PACTEC company. We set the machine at a rate 1,200 products per minute.

This produces articles packed in an envelope closed by papillotes with a presentation impeccable and excellent retention of the papillote. The packaging formed with the film of the example 1 have the distinction of being completely airtight and waterproof.

Claims (3)

1. Packaging wrapper consisting of a film (20) intended to be closed by at least one twist (22), including, on the internal side in relation to the article to be packaged (16), a cold-sealing coating placed along two parallel lengthwise strips (12, 14) on either side of the article to be packaged (16), characterized in that the film (20) has at least one transverse additional strip (24), (26) of cold-sealing coating placed along one edge . of the film (20) perpendicularly to the said lengthwise strips (12, 14) of sealing coating so as to allow, after twining of the wrapper, the latter to be closed along a direction parallel to the axis passing through the twists (22).
2. Packaging wrapper according to Claim 1, characterized in that the film (20) has two transverse strips (24, 26) of cold-sealing coating extending perpendicularly between the lengthwise strips (12, 14) along the opposite edges.
3. Packaging wrapper according to either of Claims 1 and 2, characterized in that the face of the film (20) opposite to that bearing the strips of cold-sealing coating is coated with a release coating.

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