ES2243880T3 - DOUBLE FOLDING PAPER SACK, MANUFACTURING PROCEDURE OF SUCH SACO AND USE OF SUCH SACO. - Google Patents

Abstract

A single-ply or double-ply paper bag is provided in the vicinity of its opening with a strip supporting closure mechanism. The strip forms two webs (2, 3) facing each other. Only one of the two webs is fixed to the inside face of the inner ply of the bag prior to the bag being filled and closed. An Independent claim is also included for a method of manufacturing a bag by unreeling stepwise a reel of strips comprising closure mechanism; cutting a length from the reel that is slightly shorter than the width of the opening of the bag; and fixing a single one of the two webs of the cut-off length of strip to the inside face of the inner ply of the bag, wherein the fixing step is performed while the bag is held open by spacers, e.g. clamps.

Description

Double fold paper bag, procedure manufacture of said bag and use of said bag.

The invention relates to the technical field of paper packaging for products containing fatty bodies, these products being in granulated or powder form and being sensitive to the environment (light and atmosphere), such as in particular food for pets or animals of breeding, dry food or phytosanitary products in grain or in powder.

The use of paper for the realization of Such packaging has certain advantages: ease of printing, which makes the packaging attractive to the consumer, lower price than multilayers and complexes such as those described in the US-A-6 333 061, WO-A-00/77300, WO-A-01/26897.

The invention relates more particularly to packaging with bellows and rectangular bottom of small type and average content, corresponding to a weight of the order of five hundred grams to fifteen kilos approximately.

Already known, in the prior art, packaging for dry food for pets, especially dogs and cats, formed by gluing two layers of strong paper. Dice the case, handles, also of paper, are inserted between the two layers of strong paper. These bags, with a usual content of two to four kilograms, are generally thermally sealed or by a sewing done after filling the bag.

Such bags have numerous inconvenience

A first drawback is linked to the fact that the bag cannot be safely closed again while that the consumption of some kilograms of food may correspond several weeks of ration for the animal (s). Of this first inconvenience numerous inconveniences result:

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he animal is tempted to dump the packaging, and to serve himself, what can be dangerous for your health when the food is hypercaloric or prescribed by a veterinarian;

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he packaging lets out odors that are not always pleasant for people, but that can be nice to certain insects that they can infest the sack contents and endanger health of the animals;

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the foods left in the bag are progressively deteriorated, being able to be despised by the animal and thrown away. The consumer it can be confused about the origin of this loss of appetite and incriminate and consider food wrongly, to Decide for another brand.

A second drawback is linked to the practical difficulty in opening the bag closed by sewing. Certain bags are certainly provided with a stitched lock comprising a loop and a chain made of colored threads different to distinguish them easily. Despite this, many users do not have enough patience to accommodate this sewn sack mouth and tear one of the faces of the sack, by example along the seam or cut it with scissors or with a "cutter." This second problem is numerous setbacks:

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injury risks when trim

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difficulty of making a neck large enough to allow a good exit of food, especially the beans, and small enough to allow use of an approximate sealing means such as a clamp clothes, for example.

A third drawback is linked to the use of two layers of strong paper for the realization of the body of the packaging. Under the effect of fatty bodies contained in the food is likely to stain the inner sheet of strong paper and, in the long run, that the outer sheet also stains. Packaging It will then present a less favorable aspect for sale. By On the other hand, due to the effect of the claws of cats or dogs, Packaging can be perforated or cracked, with the disadvantages of that has been mentioned above.

So far no solution has been provided to solve all these problems at once without it happening a prohibitive increase in the sale price of the bag, and unmodified its factory filling mode. It should be noted in this regard that the strong paper sacks of the technical field of the invention are delivered conventionally flat (and not in rolls or in bands), each of the bags being under a conduit of feed before closing them again.

In order to illustrate the problems not yet solved are going to present now some technical documents previous.

The document WO-A-97/46461 describes a package for food, particularly for animal feed domestic, consisting of a paper bag with bellows and handles, this packaging being provided with bands with loops and band of hooks like those sold with the Velcro® brand. A first band is located on the inner face of a first large side of the sack, in the vicinity of the upper free edge of this first side big. The second band is located on the outer face of a second large side of the sack, this second large side being provided at its upper free edge with an opening opposite of the first hitch band. A folding line allows the recess of the mouth of the bag then placing the two bands of hook in front of said opening.

The embodiment described in the document WO-A-97/46461 does not guarantee a closure noticeably tight in the bag and involves numerous operations Supplementary during bag manufacturing: the placement of two hitch bands, an opening and a folding line supplementary for the recess of the mouth of the sack. It is necessary a precise positioning of the two parts of the organs of hitch, opening and folding line to make The recess.

The embodiment described in the document WO-A-97/46461 does not provide any security against a malicious opening, since the sack is not provided with no first opening witness.

The document FR-A-2 791 040 describes a sack of bellows for conditioning bulk products such as animal feed. The bag can be stored in a way flat, filled, and then closed without any need modification of the corresponding job position.

The embodiment described in the document FR-A-2 791 040 presents numerous Disadvantages: First, the bag is made using a sheath of synthetic material such as polyethylene. In second instead, the bag is devoid of means that allow it to be closed again, a drain opening being formed by a precut line located at an angle of the bottom of the bag, in the opposite side of the bag handle.

US 6 279 298B describes a bag that comprises a bottom with bellows and an open top with a hitching band from which a first fin is fixed on the face internal of a first panel of the bag and a second being free fin. After filling the bag, the second fin will be fixed at the inner face of a second panel.

The object of the invention is to provide a paper-based packaging for grain or powder fatty products, sensitive to the environment (light and atmosphere), such as in special food for pets or livestock, not presenting this packaging the disadvantages of the known previously and allowing at the same time:

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return to close the bag to use its contents several times, thus reducing the risks of deterioration of the content of the coat;

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facilitate the opening and closing of coat;

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have a first witness opening of the bag;

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avoid that the paper of the sack be stained by the fats contained in the animal feed or any other product equivalent;

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facilitate manual transport of the bag with the help of a handle, without risk of tearing the sack, and this to despite a weight of the order of several kilograms of food or other equivalent products;

and this without modifying the process of transport of these bags, available in flat form, and without modify the filling process of these sacks

For these purposes, the invention relates, according to a first aspect, to a single fold paper bag or, advantageously double fold, provided, in the vicinity of its opening, of a band having closing means, forming this band two layers noticeably opposite each other, being only one of the two layers fixed on the inside of the fold inside the bag before filling and closing.

The bag presents, according to various embodiments, the following characteristics, eventually combined:

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the inner side of the inner fold of the bag is lined by a polymer material, coating that ensures a barrier against greases and that reduces the risks of tearing and perforation of the coat;

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the band that forms two layers and that has the closing means is made of a polymer material;

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the layer of the band fixed on the inner face of the inner fold of the sack before filling is fixed in this inner fold by hot welding or high frequency welding or welding by ultrasound;

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the layer of the band fixed on the inner face of the inner fold and the polymer coating of the inner face of this inner fold they are made of polyethylene and are weldable with each other hot to Pressure;

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the closure means comprise a male profile and a female profile that define a zipper device;

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these male and female profiles protrude slightly above the edge upper fold of the sack, so that they are visible to simple sight So it is not necessary to trim the bag with scissors or with a "cutter" to open it;

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the male and female profiles extend in a length slightly less than the width of the bag, so that the opening, as needed, by a part of the mouth of the sack, thus forming an outlet neck, or even the whole mouth from the bag when a large flow rate is desired;

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the male and female profiles can be embedded in each other and separated from each other by operating a sliding cursor manually operated;

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he Sliding opening cursor is attached, before the first opening, to one of the male or female profiles by a bridge breakable, which ensures a first opening witness;

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he sack is provided with side bellows.

The invention relates, according to a second aspect, to a bag as presented above, this bag being closed and filled, and the second layer of the band having the closure means fixed on the inner face of the inner fold of the
coat.

According to various embodiments, the closed bag It has the following characteristics, if any combined:

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the two layers of the band that has the closure means are welded each;

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the two layers of the band that has the closing means are joined each other by a repositionable adhesive such as that marketed, for example, by the 3M® company;

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the two layers of the band that has the closure means are joined by removable form;

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the first separation of the two layers is testable to the naked eye by the detachment of a colored or printed area hidden from the seen before opening the bag.

The invention relates, according to a third aspect, to a method of manufacturing a bag as presented Previously, this procedure includes:

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a step-by-step unwinding step of a web coil that it has the closing means;

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then a cutting stage, from this coil, of a bandwidth slightly smaller than the bag opening width;

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then a stage of fixing a single of the two layers of the band cut on the inside of the inner fold of the bag, this fixation being made when the sack is kept open by means of separation such as tweezers.

According to various uses, this procedure It has the following characteristics, if any combined:

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after fixing only one of the two layers of the band, the separation means are deactivated and the sack is laid flat to be subsequently reopened and fill;

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he sack is filled after fixing only one of the two layers of the cut band, keeping the mouth separation means of the bag in the open position;

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after filling the bag, the second The cut band layer is fixed on the inside of the fold interior that is located in front of him;

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the two layers of the cut band are joined together by welding;

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the two-layer welding with each other ensures at least in part, when same time as the fixing of the second layer of the band cut;

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the two welding operations are carried out thermally under pressure, the band that supports the closing means and the lining of the inner face of the inner fold of the sack of a polymeric material such as polyethylene;

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the welding operations of the second layer and the two layers between yes they are made in the bag filling chain, on the fly and in hidden time, during the transfer of the bags after fill;

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the band that has the closing means and the means are integral or assembled together.

The invention relates, according to a fourth aspect, to the use of a sack as presented above for the conditioning of food products for animals. As the person skilled in the art will understand, a bag as it has been presented above may be used for other purposes such such as the conditioning of animal beds, or Phytosanitary food products in grain or powder, dried or little wet

Other objects and advantages of the invention will appear in the course of the following description of embodiments, description to be made with reference to the attached drawings, in which:

- Figure 1 is a schematic sectional view from the top of a bag according to an embodiment;

- Figure 2 is a top view of a sack of bellows, open and full of air, according to an embodiment of the invention.

Bag 1 is of the double fold type. In others terms, bag 1 comprises two sheets of paper not attached in the all of its contact surfaces but fixed together in its edges, especially at its high and low edges.

In one mode of use, the two sheets are fixed each other using an adhesive.

The outer sheet or fold can be printed, forming the inner sheet or fold a barrier against the grease.

In one mode of use, the inner fold is made from brown kraft paper on which polyethylene is applied, especially by extrusion.

As it appears in figure 2, the bag is provided in the contour of its mouth with two layers 2, 3, whose faces external 2nd, 3rd are suitable to be fixed to the inner face of the inner fold of the bag.

In one embodiment, layers 2, 3 are of Basic polymeric polyolefin material, suitable for welding in the extruded polyethylene of the inner fold of the bag.

As the expert in the matter, depending on the nature of polymeric materials used for extrusion in the inner fold of the bag and for layers 2, 3, the welding of the layers can be done in hot, by ultrasound or by high frequencies.

The bag is provided with closing means reversible type of slide or zip closure. The profiles males 4 and female 5 of this type of closure are schematized in Figure 1, it being understood that there is a large market number of profiles and that can be used here. The forms of profiles 4, 5 of figure 1 should therefore not be considered more That as schematic.

A cursor 6 allows the opening and closing of the crellamera, by separation of male and female profiles 4, 5.

The sack comprises first witness means opening such as, especially, the breakable bridge that joins the cursor and one of the profiles 4, 5, this breakable bridge being broken at the time of the first manual opening of the zipper.

If necessary, the two internal faces 2b, 3b are weldable together to form a removable joint, for example, by application on these two internal faces of an adhesive repositionable, of a preprinted message on the faces being visible after detachment

As a variant, the two internal faces 2b, 3b do not they are weldable to each other except in a colored band of union by welding, separation of layers 2, 3 leaving this band colored in view of the consumer.

Reference is now made more particularly to the figure 2.

One of the layers 3 is welded in the fold inside the bag while the other layer 2 remains free.

The bags can be delivered by plane and factory filled according to conventional technique: unstacking the sack and transfer to the filling station where tweezers They keep the mouth of the bag open. The zipper does not hinder the step of the products that have to go in the bags. In addition, after its filling, the bags can be resealed in a single operation: a thermal welding will ensure at the same time the fixation in the inner fold of the coat coat that remained free 2, and the removable fixing or eventual welding of the two layers 2, 3 each.

The improvements made to the bag do not have this way no effect on the structure of the filling machine and of closing.

Profiles 4, 5 extend over approximately almost the entire width of the mouth of the bag 1, being layers 2, 3 hidden from view by the two folds of the bag one.

Now a mode of placement of This zipper

In a first stage, the bags are unstacked and carried by a conveyor to a first position. The sack is then open due to the application of tweezers in the bag. The zippers-cursors are unwound from a coil, the band can be provided with zones 7 in which the profiles 4, 5 are crushed and soldiers with each other. These zones 7 are sensitively equidistant a length slightly less than the width L of a large side of the bag.

The zipper coil unwinds from one coil step by step and is trimmed to the right of each zone 7. The clipped zipper, provided with its cursor, is then deposited in the bag and one of the layers 2, 3 is fixed on the inner face of the inner fold of the bag.

In one mode of use, the fixing of the layer is it is carried out at a temperature of the order of 230ºC, with a pressure of order of 0.4N for 15 mm2, the welding time being 1.5 second order.

Once the layer is welded, it is remove the tweezers that kept the sack open, being returned to place the bag flat for stacking and palletizing.

Bag 1 can be provided with handles for facilitate your grip, especially for weights greater than three kilograms These handles, made of paper, rope or plastic, are kept by gluing, welding or fastening, especially between two folds of the sack, in the way it is already known.

The bag according to the invention has numerous advantages:

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is possible to close it again, to use its content in several times, reducing the risks of deterioration of the sack contents due to the relative tightness ensured by the contact of the sliding closure profiles;

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no easily let off odors fired by products that contains;

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is provided with first opening witnesses of the bag;

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he lining of its inner fold allows it to be stained by fats contained by animal feed or by any other similar product;

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its Manual transport is easy, with the help of one or two handles, without risk of tearing, and this despite a weight of the order of some kilograms of food or other similar products;

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being based on paper, recycling poses fewer problems than in the case complex or multilayer, and its price is modest;

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its use does not imply the transformation of the structure of filling machines;

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follow being deliverable in flat form, in normal pallets.

Claims (25)

1. Single or double fold paper bag, characterized in that it is provided, on the one hand, with side bellows and, on the other hand, in the vicinity of its opening, of a band having closing means, this band forming two layers (2, 3) substantially opposite each other, being fixed only one of the two layers on the inner face of the inner fold of the bag before filling and closing. 2. Paper bag according to claim 1, characterized in that the inner face of the inner fold of the bag is coated with a polymeric material. 3. Bag according to claim 1 or 2, characterized in that the band forming the two layers (2, 3) and having the closure means is made of a polymeric material. 4. Bag according to claim 2 and 3, characterized in that the layer of the band fixed on the inner face of the inner fold of the bag before filling is fixed in this inner fold by thermal welding or high frequency welding or by ultrasonic welding . 5. Bag according to claim 4, characterized in that the layer of the band fixed on the inner face of the inner fold and the polymer coating of the inner face of this inner fold are made of polyethylene and are heat weldable together under pressure. 6. Bag according to any one of claims 1 to 5, characterized in that the closure means comprise a male profile and a female profile (4, 5) defining a zipper. 7. Bag according to claim 6, characterized in that the male and female profiles (4, 5) protrude slightly above the upper edge of the double fold of the bag, so that they are visible. 8. Bag according to claim 6 or 7, characterized in that the male and female profiles (4, 5) extend in a length slightly smaller than that of the bag width. 9. Bag according to any one of claims 6 to 8, characterized in that the male and female profiles (4, 5) can be interwoven into one another and separated from each other by the operation of a sliding cursor (6). 10. Bag according to claim 9, characterized in that the opening slide slider (6) is attached, before the first opening, to one of the male or female profiles (4, 5) by a breakable bridge. 11. Bag according to any one of the claims 1 to 10, wherein this bag is closed, the second layer of the band that supports the closing means is fixed on the inner face of the inner fold of the sack. 12. Bag according to claim 11, characterized in that the two layers of the band having the closure means are welded together. 13. Bag according to claim 11, characterized in that the two layers of the band having the closure means are joined together by a repositionable adhesive. 14. Bag according to claim 11, characterized in that the two layers of the band having the closure means are detachably joined. 15. Bag according to any one of claims 12 to 14, characterized in that the first separation of the two layers (2, 3) can be seen with the naked eye by taking off a colored or printed area hidden from view before the opening of the coat. 16. Method of manufacturing a bag such as that presented in any one of claims 1 to 15, characterized in that it comprises:

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a step-by-step unwinding step of a web coil that it has the closing means;

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then a cutting stage, from this coil, of a bandwidth slightly smaller than the bag opening width;

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then a stage of fixing a single of the two layers of the band cut on the inside of the inner fold of the bag, this fixation being made while The bag is kept open by means of separation such as tweezers.

17. Method according to claim 16, characterized in that after the fixing of only one of the two layers (2, 3) of the band, the separation means are deactivated and the sack is returned to be flat to be subsequently returned to open and fill. 18. Method according to claim 16, characterized in that the bag (1) is filled after fixing only one of the two layers (2, 3) of the cut band, the separation means keeping the bag mouth in the position of opening. 19. Method according to claim 17 or 18, characterized in that, after filling of the bag, the second layer of the cut band is fixed on the inner face of the inner fold that is located in front of it. 20. Method according to claim 19, characterized in that the two layers of the cut band are joined together by welding. 21. Method according to claim 20, characterized in that the welding of the two layers together is at least partly secured, at the same time as the fixing of the second layer of the cut band. 22. Method according to claim 21, characterized in that the two welding operations are thermally carried out under pressure, the band supporting the closing means and the lining of the inner face of the inner fold of the sack being made of a polymer material being carried out. such as polyethylene. 23. Method according to any one of claims 19 to 22, characterized in that, the welding operations of the second layer and the two layers together are carried out in the bag filling chain, on the fly, during the transfer of the bags after filling. 24. Method according to any one of claims 16 to 23, characterized in that the band having the closing means and the closing means are integral or assembled together. 25. Use of a bag such as the one presented in any one of claims 1 to 15 for the packaging of food products, products Phytosanitary products in grain or powder, dry or slightly damp.