MXPA99007221A - Bag-in-bag packaging system - Google Patents

Abstract

Packaging such as a block-base sack (201) suitable for packing of particulate material has an inner bag (not shown) having two layers of polyethylene, surrounded by an outer bag (201) having three layers of polyethylene. Each bag has a closed bottom and an open top (208) prior to filling. After filling of the inner bag, the inner bag is closed by a first heat seal along zone (205) in a heat sealing operation which can be performed through the outer bag (201) in such a way that the outer bag (201) is not heat sealed to the inner bag at that point. The outer bag (201) is closed by a second seal (207) located between the first seal (205) and the top of the bag (208). A frangible zone (206) is located between the first (205) and second (207) heat seals to enable the outer bag (201) to be removed from the sealed inner bag by cutting or tearing along the frangible zone (206).

Description

PACKAGING SYSTEM BAG IN BAG FIELD OF THE INVENTION The invention relates to packaging and, in particular to flexible multi-pleat packaging, such as bag-in-bag packaging systems. More specifically, the invention relates to top closure systems for said flexible packaging formed from plastic material and having an inner bag within an outer bag, but separated from it. Said packaging is suitable for food or materials with food grade or pharmaceutical products.

BACKGROUND There is a use of flexible packaging that offers an external packaging that acts as protective packaging or industrial shipping, combined with an internal packaging that can be removed from the outer packaging, although it remains sealed. The removable inner packaging acts to deliver a hygienically packaged product that has not been contaminated during shipment and that is suitable for being taken to areas of critical food hygiene.

There is a need to provide a flexible package as described above, which is manufactured quickly and can provide a sealed pouch bag method.

DEFINITIONS The term 'bag' means a container made of one or more folds of a flexible material, closed at least at one end. The term includes, but is not limited to, 'sacks, bags, sachets and sachets', of any size or shape. The term 'sack' is often used for containers capable of containing between 10 and 40 kg of product, although the size of such varies from country to country. 'Bag' or 'saquillo' is sometimes used to refer to containers with a capacity of less than 10 kg of product. However, in the present specification the term 'bag' is used in its generic sense, whatever the weight of the product for which it is used. In its most preferred form, the specification describes 802008.doc / JP / gg a 'bag in bag' packaging system able to contain 25kg of milk powder or derivatives thereof, which in many countries would be referred to as 'sack'.

'Sack' means a bag made essentially of one or more flattened tubular folds of flexible material, such as paper or plastic, closed at least at one end.

'Fold' refers to a flexible material that forms the walls of a bag (or bag). The term "two-fold bag" refers to a "bag-in-bag" packaging system, that is, "inner fold" refers to a wall of the "inner bag".

'Film' refers to a flexible material, typically a 'plastic' material, whether comprising one layer or more than one layer of material.

OBJECT It is a purpose of this invention to provide an improved package or improved closure system for a flexible multi-pleat packaging, or at least one that gives the public a useful option.

APPROACH OF THE INVENTION In general, it can be said that in one aspect, the invention consists of a bag of at least two folds, which includes an internal fold inside an outer fold, but can be removed from it, a mouth of the bag incorporating internal sealing means and external, the internal sealing means adapting only the internal fold for sealing, and the external sealing means adapting at least the outer fold for sealing.

We use the term "two-fold bag" to refer to the "bag-in-bag" packaging system, that is, "inner fold" refers to a wall of the "inner bag".

Preferably, a gible zone is provided between the internal sealing means and the external sealing means at least in the outer fold. 802008 English.dsc / JP / gg More preferably, the gible zone is in a weakened line formed at least in the material of the outer fold.

Preferably, the gible zone is formed by a weakened line in both the material of the inner fold and the material of the outer fold.

Preferably, the internal seal and the outer seal are achieved by applying heat through the layers of the inner fold and the outer fold.

Optionally, a non-sealable layer can be provided between the inner fold and the outer fold around the inner seal means of the inner fold, or alternatively, the inside folds can be sealed, leaving the outer fold unsealed, by an appropriate selection of time / temperature / pressure and materials.

Preferably, the non-heat-sealable layer is chosen from the group including (but not limited to): solvent based lacquer lacquers, solvent lacquers to water, and silicone dispersions.

Preferably, at least the inner fold is made of weldable plastic material.

More preferably, the weldable plastic material is thermoplastic or composites of thermoplastic and other materials, including inter alia, paper coated in polyethylene and spun polypropylene coated in polyethylene.

In another aspect, it can be said that the invention generally consists of a method of sealing a bag of at least two folds, including an internal fold inside an outer fold, but removable from it, a mouth of the bag incorporating internal and external sealing means, the internal sealing means adapting only the internal fold for sealing, and the external sealing means adapting at least the outer fold for sealing. 802008.doc / JP / gg Preferably, a frangible zone is provided between the internal sealing means and the external sealing means at least in the outer fold.

More preferably, the frangible zone is in a weakened line formed at least in the material of the outer fold.

More preferably, the frangible zone is formed by a weakened line in both the material of the inner fold and in the material of the outer fold.

Preferably, the internal seal and the external seal are achieved with the application of heat through the layers of the inner fold and the outer fold, with the provision of a non-sealable layer between the inner fold and the outer fold around the middle. internal seal of the inner fold.

Preferably, the non-heat-sealable layer is chosen from the group including, but not limited to: solvent based lacquer lacquers, solvent lacquers to water, and silicone dispersions.

Preferably, at least the inner fold is made of weldable plastic material.

More preferably, the weldable plastic material is thermoplastic or thermoplastic composites and other materials, including inter alia, polyethylene coated paper and polyethylene spun polypropylene.

In another aspect, it can generally be said that the invention consists of a multi-pleated bag with an internal fold and an outer fold constructed of heat-sealable material, the inner fold contained within the outer fold, but removable from it, where applies a strip of non-sealable material to the heat inside the outer fold, or on the outside of the inner fold, near or adjacent to an open end of the outer fold or the inner fold.

Preferably, the non-sealable material is applied to the heat inside the outer fold. 802008.doc / JP / gg Preferably, the non-heat sealable layer is selected from the group that includes (but is not limited to): solvent based lacquer lacquers, water solvent lacquers, and silicone dispersions. .

Preferably, a frangible zone is provided at least in the material of the outer fold, in the region of the non-heat-sealable material, or on the non-heat-sealable material.

More preferably, the frangible zone is in the region of the non-heat sealable material.

Preferably, the frangible zone is formed by a weakened line that is formed at least in the material of the outer fold.

In another aspect, it can generally be said that the invention consists of a method of sealing a bag of at least two folds constructed of heat-sealable material, having an internal fold within an outer fold, but removable from it, wherein a strip of non-sealable material is applied to the heat inside the outer fold, or on the outside of the inner fold, near or adjacent to an open end of the outer fold or the inner fold.

Preferably, the non-sealable material is applied to the heat inside the outer fold.

Preferably, the non-heat-sealable layer is chosen from the group including, but not limited to: solvent based lacquer lacquers, solvent lacquers to water, and silicone dispersions.

Preferably, a frangible zone is provided at least in the material of the outer fold, in the region of the non-heat-sealable material, or on the non-heat-sealable material.

More preferably, the frangible zone is in the region of the non-heat sealable material.

Preferably, the frangible zone is formed by a weakened line that is formed at least in the material of the outer fold. 802008.doc JP / gg Preferably, at least one thermal seal is applied to the two-ply bag, and said thermal seal-extends above and below the region of application of the non-sealable material to heat.

Alternatively, two heat seals are applied in the two-fold bag, an upper seal being applied over the frangible zone and a lower seal around the application region of the non-heat-sealable material.

In another aspect it can be said that the invention generally consists of a multi-pouch bag with an internal fold and an outer fold constructed of heat-sealable material, the inner fold contained within the outer fold, but removable from it, where applies a strip of heat sealable material to the inside of the outer fold, or to the outside of the inner fold, near or adjacent to an open end of the outer fold or inner fold.

Preferably, the heat sealable material is applied inside the outer fold.

Preferably, a frangible zone is provided at least in the material of the outer fold, in the region of the heat sealable material or on the heat sealable material.

More preferably, the frangible zone is provided in the region of the sealable material. hot.

Preferably, the frangible zone is provided by means of a weakened line formed at least in the material of the outer fold.

In another aspect, it can generally be said that the invention consists of a method of sealing a bag of at least two folds constructed of heat-sealable material, having an internal fold within the outer fold, but removable from it, wherein a strip of heat sealable material is applied to the inside of the outer fold, or to the outside of the inner fold, near or adjacent to an open end of the outer fold or the inner fold. 802008.doc / JP / gg Preferably, the heat-sealable material is applied to the inside of the outer fold.

Preferably, a frangible zone is provided at least in the material of the outer fold, in the region of the heat-sealable material, or on the heat-sealable material.

More preferably, the frangible zone is provided in the region of the heat sealable material.

Preferably, the frangible zone is provided by a weakened line that is formed at least in the material of the outer fold.

Preferably, at least one thermal seal is applied to the two-ply bag, and said thermal seal is applied at least in the region of the heat-sealable material.

In another aspect, the invention provides packaging, including an inner bag having an inner surface and an outer surface, surrounded by an outer bag, but removable from it, which has an inner surface and an outer surface, each bag with a base closed and each bag with a top opening, wherein the inner surface of the mouth of the inner bag has a heat-sealable area, and the inner surface of the mouth of the outer bag has (a) a non-heat-sealable area that corresponds to the location of the heat-sealable area of the inner bag, and (b) a sealable area between the non-heat-sealable zone and the upper part of the bag, so that in use a heat sealing operation can be performed through the outer bag to create a first seal capable of closing and sealing the mouth of the inner bag, without sealing the outer bag in this area do not seal the heat, and that a sealing operation may be performed at least on the outer bag to create a second seal that closes and seals the outer bag in the sealable area to enclose the sealed inner bag within the outer bag.

In a further aspect, the invention provides a method of filling and sealing packaging of the type described in the immediately preceding paragraph, with an inner bag surrounded by an external bag, but removable from it, wherein the package is taken to a machine filling until the inner bag is filled with the desired amount, the mouth of the bag is 802008 English.doc JP / gg stretches to flatten the inner and outer bags in the region of the first and second sealing zone, the inner bag is sealed in the first sealing zone to create a first seal without adhering to the outer bag , while the inner bag and the outer bag are sealed together in the region of the second sealing zone to create a second seal.

In still another aspect of the invention, there is provided a package including packaging as described above, in which a filled inner bag is surrounded by an outer bag, but is removable from it, the inner bag is closed by a first thermal seal, but the outer bag is not thermally sealed to the inner bag at that point, the outer bag is closed by a second seal located between the first seal and the top of the bag, and there is a frangible zone between the first and second seal so that in use, the outer bag can be detached from the sealed inner bag by cutting or tearing along the frangible zone.

In another aspect, the invention provides a method of emptying the package as described in the preceding paragraph, wherein the second seal is torn off by tearing or cutting along the frangible zone between the first and second seal, and the inner bag Fully sealed is detached from the outer bag.

DRAWINGS - Next, a description is given of the preferred forms of the invention, given by way of example only, and with reference to the drawings, in which: Figure 1 shows a lateral cross section of an upper portion of a two-fold bag, which presents the configuration of the seal.

Figure 2 illustrates a bag with block base ready for filling.

Figure 3 illustrates the bag of Figure 2 filled and sealed.

Figure 3A illustrates a sectional view of line A-A of the bag of Figure 3. 802008 English.doc JP / gg Figure 4 illustrates the bag of Figure 3 with the outer bag partially open,. - -showing the opening of the outer bag, by tearing or cutting through the lines of the perforations.

Figure 5 illustrates a modified base bag with the patch providing the gripping means.

Figure 6 illustrates a modified patch of normal length, which also provides a means of gripping the base of the bag.

Figure 7 illustrates an alternative scheme in which the patch is secured to both edges of the base of the bag.

Figure 8 illustrates a flush cut closure for a two-fold plastic bag having a first thermal seal, and a second thermal seal separated by a line of perforations.

Figure 9 shows a flush cut closure for a double fold plastic bag, having a first thermal seal, a line of perforations, and a separate lid capable of joining the upper part of the inner and outer bag.

Figure 10 illustrates a stepped top closure for a double fold plastic bag having a first thermal seal, a line of perforations, and a hot melt or pressure sensitive adhesive that is within the stepped top.

Figure 11 illustrates the bag of Figure 10 with a compression top closure for a double-fold plastic bag having a first thermal seal, a line of perforations, and a flap over the outer bag, capable of being bent and sealed to cover the internal bag 802008.doc / JP / gg Figure 12 illustrates a schematic diagram of a plastic conversion machine capable of producing the bags of this invention.

Figure 13 illustrates a bulky bag pouch scheme for liquid transport, seen before sealing.

Figure 14 illustrates the bag-in-bag scheme of Figure 13, with the neck of the two bags sealed according to this invention.

Figure 15 is a cross section of the construction of a bag in its most basic form to eliminate the need to apply lacquer.

Figure 16 is a cross-section of a preferred bag construction, utilizing a combination of a two-layer inner bag with a three-layer outer bag to eliminate the need to apply lacquer.

Figure 17 illustrates a cross section of a preferred bag construction, similar to that of Figure 16, with the additional feature that the inner bag provides an oxygen barrier.

FIRST EXAMPLE A two-ply bag can be formed with commercially known means. The folds of the bag can be formed with thermoplastics or thermoplastic composites and other materials, such as polyethylene coated paper or polyethylene spun polypropylene. It is a feature of this invention that the resulting bag has an inner bag inside an outer bag, but that it is removable from it. The outer bag can be removed after transport and the inner bag can be taken to areas of critical food hygiene, since the inner bag has remained unpolluted during transportation and handling. 802008.doc / JP / gg A multi-pleat bag 100 is provided, with an inner fold 101 and an outer fold 102. At least one end of the inner fold 101 and at least one end of the outer fold 102 may closing to form an inner bag and an outer bag respectively, each with an open end. Both the inner fold 101 and the outer fold 102 are constructed of heat sealable materials, for example, thermoplastics or thermoplastic composites, polyethylene coated paper and polyethylene spun polypropylene.

A non-sealable material is applied to the heat 103, such as solvent-based varnish lacquers, water-based varnish lacquers or silicone dispersions, in a strip inside the outer fold 102 near the open end of the outer bag.

The bag 100 can be delivered to a customer for filling and sealing. Then, in use, two thermal seals can be applied in the package.

A lower heat seal 104 is applied in the position of the non-heat sealable material 103. An upper heat seal 105 is applied above and parallel to the lower heat seal 104. Preferably, a gap is left between the lower heat seal 104 and the seal upper thermal 105. A frangible zone 106 is provided, preferably both in the inner fold 101 and in the outer fold 102 at a position between the lower heat seal 104 and the upper heat seal 105. Preferably, the frangible zone 106 is formed by means of perforations made in the inner fold 101 and the outer fold 102 in the heat sealing step, or immediately after it. The frangible zone 106 allows the outer fold 102 to be easily removed from the inner fold 101 without affecting the integrity of the inner seal 104.

The lower heat seal 104 and the upper heat seal 105 are formed by the application of heat. The non-heat sealable material 103 allows the lower heat seal 104 to seal only the inner fold 101 to close and seal the inner bag. 802008 English.doc / JP / gg Preferably, the upper thermal seal seals together the inner fold 101 and the outer fold 102, "although if the inner bag is missing to reach the top of the outer bag, only the bag could be sealed in the upper thermal seal 105.

Alternatively, only one thermal seal can be applied in the multi-pleat bag 100. The thermal seal is applied in the region of the non-sealable material to the heat and extends over the non-sealable material to heat, thus sealing the inner fold and the outer fold together on top of the non-heat sealable material. In this alternative, the frangible zone is in the region of non-heat-sealable material.

If desired, an outer paper fold can be used. If the outer paper fold is used, the inside of the outer paper fold is coated in polyethylene or another thermoplastic, at least in the region where the thermal seal or the upper thermal seal is to be applied (in case it goes away). to apply an upper and lower thermal seal), to allow the thermal seal to be made between the internal fold and the external fold above the frangible zone.

In use, the inner bag is filled and the multi-pleated bag is sealed in the manner described above. After the formation of the seals closing the multi-pleat bag 100, and transportation to its destination, the outer bag can be opened through the frangible zone 106, leaving the inner bag sealed. Then, you can remove and discard the 'outer bag while the inner bag remains intact and sealed.

SECOND EXAMPLE In its most preferred form, the bag is formed as a bag with a block bottom of the type shown in Figures 2, 3, 3 A and 4. This bag is particularly suitable for the packaging of milk powder and milk derivatives powder, and therefore the bag-in-bag construction of the present invention could be used to produce a 'bag' capable of containing 25 kg of milk powder. As an example, such a 'bag' could measure 800-900 mm in height, around 400 mm in width, and approximately 140 to 180 mm in depth. With these dimensions, the upper section of the 'sack' used for the first and second 802008 Sparüsh.doa'JP / gg seal, (the sealed portion shown in Figure 3 A), would measure approximately 150 mm in height. ^ This bag has an inner bag (not shown) surrounded by an outer bag 201 having a block base 202 covered by a patch 203. Prior to filling, the bag has a non-heat-sealable region 205 corresponding to a region Sealable to the heat of the inner bag, which will form a first seal to close the inner bag. After sealing, a frangible zone 206 can be provided by line 206 to separate the first seal from a second seal that can be provided in zone 207 to seal at least the outer bag. The interrupted line 208 indicates the back seam of the outer bag.

In this embodiment it is possible to form the inner and outer pouch of different or slightly different plastic materials, having different seal initiation points. In making the inner bag of, for example, polyethylene with a seal initiation point of for example 10-15 ° C less than the seal initiation point of the outer bag, which could also be formed of polyethylene, is it is possible to control the time and the application temperature of the thermal sealing bars to effect the first seal at a temperature lower than that of the second seal. If the time, temperature and application pressure of the first set of sealing bars is controlled, so that there is sufficient heat through the outer bag to melt and thus seal the inner bag without permanently adhering to the outer bag , so it is possible to seal the inner bag in the area 205, and then giving a sufficient application time or a higher temperature for the second set of sealing bars it is possible to impart sufficient heat to seal the outer bag to the inner bag in the area 207. Either the inner bag or the outer bag may be formed of a multilayer plastic web, depending on the type of materials to be packed inside the bag.

Figure 3 illustrates the bag in bag of Figure 2 once filled and sealed. Note that numerals 205-207 are used in Figure 2 to refer to the areas in which seals and perforations are made when the bag is closed and sealed after filling, but in Figure 3 these same numerals are used to refer to the location of seal 205 made in the internal bag, the location of seal 207 made in the bag 802008 English.doc / JP / gg external and internal bag, and perforations 206 that extend through the external bag and lálJOlsa internal.

Figure 3A illustrates the sealed bag in Figure 3 in cross section to show the contents 209. The inner and outer bags closely fit together, and have not been distinguished in the drawing.

Figure 4 illustrates the bag of Figure 3 with the outer bag partially open, so that the second seal 207 can be peeled off by tearing or cutting by line 206 of perforations.

Figure 5 illustrates the block base of such bag (as seen in Figures 2 to 4), where patch 213 is elongated (i.e., is longer than patch 203), and thus provides two extension fins 214, 215, which do not adhere to the base of the bag, thus forming a means of grip. A typical length in this type of gripping means would be 35 mm at each end of the patch 213.

When the bag of Figure 5 arrives at its destination, the upper part of the outer bag can be removed by pulling or cutting along the line of perforations, and then the bottom of the outer bag can be grasped with the fins 214, 215, and the inner bag can be dropped into a feeder tank or other receptacle, while the process operator holds the fins of the outer bag, the weight of the inner bag material will cause it to detach from the outer bag. As will be apparent from the manufacturing description of a block base bag according to this invention, it is desirable to lightly fasten, or secure, the inner bag to a lower portion of the outer bag during manufacture and bending of the base. of the external bag. In which case, it is desirable that the union be by some form of adhesive that will release the outer bag in this discharge operation.

Figure 6 illustrates a modified normal length patch 223, in which the adhesive is applied to the patch in all the cavities, except 224, 225, so that the patch has two manual grip regions 227 at each end of the patch. 802008.doc / JP / gg Figure 7 illustrates an alternative scheme in which the patch 233 is secured by both edges 234 -, - 235 to the base of the bag, and in the central region, as marked, and the patch has two sets of serrations or perforations 236, 237, which allow the bottom of the bag to be grasped in a similar manner to that of Figure 5, or, alternatively, the ends of the patch can be pulled, to produce two erect portions of the patch to facilitate the grip, causing the ends of the patch to tear through the indentation lines 236, 237.

Figures 8-11 show, in isometric view, upper closure variations in a bag system in multiple pleated plastic bag. In each of these Figures the outer bag is represented by the numeral 801 and the inner bag is represented by the numeral 802. It will be appreciated that these are schematic drawings, to illustrate the relationship of the first seal 803 used to seal the inner bag 802 and the second seal used to seal the outer bag. In Figure 8, the bag has a flush cut closure (so that the upper part of the outer bag 802 is cut flush and corresponds to the upper part of the outer bag 801). In this case, the inner bag is thermally sealed at 803, without the corresponding portion of the outer bag being sealed by the inner bag at 803, while the outer bag is heat sealed at 804 a little above the location of the thermal seal 803. This thermal seal 804 seals through the internal and external bag at that point. A line of perforations 806 can be cut through the bag, to allow the upper part of the bag to be easily removed, and to release the sealed inner bag from the outer bag 801 which is now to be discarded.

Figure 9 also illustrates a flush cut closure, but in this case the upper part of the inner and outer bag 801, 802 are covered with a lid. For convenience, it can be made of polyethylene or paper, which can be heat sealed, glued, sewn, or otherwise sealed in place. This cap 807 can be sewn through the inner bag and the outer bag 801 and 802 and a line of perforations 806 can be provided that extends through the inner bag and the outer bag, and if desired through the bag. corresponding portion of the lid.

Figure 10 illustrates an upper stepped closure, in which the inner bag is heat sealed at 803, and the stepped upper flap portion 808 of the outer bag has a layer 802008.doc / JP / gg of adhesive 809, commonly a hot melt adhesive, or a pressure sensitive adhesive, allowing the top flap 808 to be sealed against the outer face of the outer bag 801.

Figure 11 illustrates an upper stepped flap closure, in which the outer bag 801 has a flap 808 capable of extending over the top of the inner bag 802, and sealing against the outer face of the outer bag 801. A The inner bag is heat sealed at 803, and a line of perforations is provided at 806 that extends through the top of the inner bag and the outer bag. Line 806 is located above thermal seal 803 and preferably below the lower edge of flap 808.

THIRD EXAMPLE A two-fold bag, with an inner fold and an outer fold, can be formed with commercially known means. The inner fold and the outer fold are constructed of materials that can not be thermally sealed together, for example, the inner fold may be made of polyethylene and the outer fold may be made of spun fabric or paper. At least one end of the inner fold is closed to form an inner pocket and at least one end of the outer fold is closed to form an outer pocket.

A heat-sealable material is applied in a strip near an open edge of the inside of the outer fold, or near an open edge of the outside of the inner fold. There is a frangible zone at least in the outer fold, piercing the outer fold under the heat-sealable material.

A multi-pleated bag is sealed by the application of heat in the region of heat-sealable material and below the frangible zone. The inner fold is sealed below the region of heat-sealable material. The outer fold and the inner fold are sealed together in the region of heat-sealable material. 802008.doc JP / gg In use, the inner bag is filled and the multi-pleated bag is sealed in the manner described above. After the formation of the seals that close the bag with multiple folds, the outer bag can be opened through the frangible zone, leaving the inner bag sealed. Then, the outer bag can be removed and discarded, while the inner bag remains intact and sealed.

FOURTH EXAMPLE This is similar to the Second Example, in that the construction of the plastic bag in bag is used. Figure 15 illustrates a cross section of this type of bag construction, in its most basic form, to eliminate the need to apply lacquer. In this scheme, the inner bag 401 is formed from a single layer of plastic material, the two sides of which are shown by the letter C as seen in the cross section. The use of the letters A-E in Figures 15-17 helps to illustrate the different materials used for the different components of the inner bag and the outer bag. In this example, the inner bag 401 is formed from a single layer of plastic material, while the outer bag 402 is formed with a double layer of plastic material, whose outermost layer is formed with the material "A" , while the inner layer of the outer bag is formed with the material "B".

In this example, material "A" is generally linear low density polyethylene ("LLDPE") whose density is 900-930 kg / m3.

Preferably, the material "B" is linear medium density polyethylene ("LMDPE"), with a preferable density of 935-940 kg / m \ Preferably, the material C of the inner bag is formed with a material of density less than 926 kg / m3, whereby it has a lower seal initiation point than the material "B" (the inner surface or the inner layer of external bag 402). Such a bag is suitable for containing a stable product, that is, one that does not require an oxygen barrier or something similar. 802008.doc / JP / gg FIFTH EXAMPLE Figure 16 illustrates a system in which the inner bag 501 is formed with a two-layer plastic web comprising the "D" and "E" materials, while the outer bag 502 is formed by a three-layer plastic web comprising the materials "A", "B" and "C". In this example, the letters A-E do not represent the same materials as the letters A-C of figure 15. The letters are used to show the difference between the different layers.

In this example, with reference to Figure 16, material "A" is generally linear low density polyethylene ("LLDPE") preferably of a density under 918 kg / m3. The material "B" is preferable "LLDPE" of a density between 900-930 kg / m3.

Preferably, the materials "C" and "D" are "LMDPE" with a density between 935-940 kg / m3.

Preferably the material "E", which forms the inner surface of the inner bag 501, is formed with a material whose density is less than 926 kg / m3. Some examples of suitable polyethylene are "LLDPE" and "VLDPE". Generally, this material has a seal initiation point less than 107 ° C.

This bag could also be used for a stable product, in a similar way to that of the Room * Example.

SIXTH EXAMPLE This example is similar to the Fifth Example, with the addition of an oxygen barrier. The inner bag 601 is formed by five layers, which are described below, while the outer bag has three layers similar to those of the Fifth Example. In each case, the Fourth, Fifth and Sixth Examples illustrate the constructions in which the inner and outer bags are formed with materials having different seal initiation points, thereby minimizing the need to use a lacquer application. By choosing properly 802008.doc / JP / gg the seal initiation points of the different surfaces of the inner bag or the outer bag, it is possible to eliminate the need to apply lacquer.

In this example, with reference to Figure 16, the material "A" is generally linear low density polyethylene ("LLDPE"), preferably with a density less than 918 kg / m3. Preferably, the material "B" is "LLDPE" of a density between 900-930 kg / m3.

Preferably, the materials "C" and "D" are "LMDPE" of a density between 935-940 kg / m3.

Preferably, the material "E", which forms the inner surface of the inner bag 601, is formed with a material having a density of less than 926 kg / m3. Some examples of suitable polyethylene are "LLDPE" and "VLDPE". Said material, in general, has a seal initiation point less than 107 ° C.

The inner bag also includes adhesive and oxygen barrier materials between layers "D" and "E". Preferably, there is an oxygen barrier material such as ethylene vinyl alcohol copolymer "EVOH" at 603, located between two layers 604 of adhesive material, such as polyethylene grafted with maleic anhydride. It will be appreciated that these are only examples, and that other barrier materials can be used, with or without other adhesives. Examples include polyamides and other barrier polymer materials.

In use, the bag-in-bag construction described with reference to the second example, and with reference to any of the Fourth-Sixth Examples, operates in such a way that the thermal seal can be achieved by applying appropriate time / temperature / pressure to the outer surface of the outer bag, for example, bags 402, 502, 602, with sufficient heat transmitted to the inner surfaces of the inner bags 401, 501, 601, such that the inner surfaces of the inner bag can be sealed between yes thermally, without the outer surfaces of the inner bag adhering permanently to the inner surface of the outer bag. 802008.doc / JP / gg Manufacture of Plastic Bags Next, the manufacture of bags according to the Second Example will be described. The Second Example referred to bags of the type shown in Figure 2, in which both the inner and outer bags are formed of a similar plastic material, such as polyethylene, and the difference between the bags is a starting point of slightly different seal, so that the inner bag has a seal initiation point slightly lower than the seal initiation point or sealing point of the outer bag.

Figure 12 is a schematic diagram of a typical plastic conversion machine for the processing of tubular and plain weave materials, both single and double layer. Preferably, the inner bag is formed by a continuous plastic tube, while the outer bag is formed from a flat plastic web, which is then folded around the inner tube to form the outer bag. It will be appreciated that in some cases the inner bag could also be formed, on the spot, from a flat plastic web, prior to the formation of the outer bag around the inner bag.

Figure 12 illustrates the following modules: 901 is a unit for unrolling the outer weft. 902 is a treatment post for the integral plot. 903 is a flexigraphic printer. 904 is a hot melt interlayer bonding unit. 905 is a training table. 906 is a longitudinal joint unit. 907 is a unit for unrolling the internal frame. 802008.doc / JP / gg Both the inner bag and the outer bag can be printed, although it is more logical to print only the outer bag, since it will be visible in transit, then the outer bag can be removed before using the bags. contents of the internal stock market. 802008 English JP / gg The inner bag is preferably formed from at least two layers of polyethylene, wherein the cap of the inner bag has a lower sealing initiation point than the outer layer of the inner bag, as shown in FIG. will explain later with reference to the outer bag layers. Preferably, the inner layer of the inner bag comprises polyethylene with a density lower than 926 kg / m, since they will have a seal initiation point less than 107 ° C. Among the suitable polyethylenes are linear low density polyethylene ("LLDPE") and very low density polyethylene ("VLDPE").

The outer bag is preferably formed from a three layer polyethylene flat web. If the bag is to be used to contain powdered milk, it is preferable that one of the layers be a light filter layer, such as dark or black plastic and it would be more appropriate for it to be the inner layer of the outer bag.

Preferably, the outer layer of the outer bag is white, or pastel (for printing purposes) and preferably, the outer layer is formed with a plastic material of high coefficient of friction, such as very low density polyethylene (" VLDPE "), to allow the outer bags do not slip when stacked. The three layers of the outer bag include a middle layer, usually made of white plastic material, such as polyethylene.

Typically, the innermost layer of the outer bag is linear medium density polyethylene ("LMDPE"), with a seal initiation point 15 ° C greater than the seal initiation point of the inner surface of the bag. inner bag, so that, for example, the innermost layer of the outer bag can be formed of medium density polyethylene LMDPE of 940 kg / m3 with a seal initiation point of 120 ° C. In most cases, it is preferable to minimize the temperature differential between the seal initiation point of the layer inside the outer bag and the outer surface of the inner bag, while maximizing the initiation point of seal of the inner layer of the outer bag together with the outer layer of the inner bag, with respect to the inner layer of the inner bag. By maintaining this difference at a minimum of 10 ° C, the use of an applied lacquer is avoided. Alternatively, in some cases the seal initiation points may be the same, in which case, lacquer, or another non-sealing layer may be applied to the heat on the inner surface of the outer bag, or the outer surface of the inner bag. 802008 English.doc JP / gg As will be seen in Figure 12, the outer weft is unwound, printed, and a hot-melt adhesive is applied to it before passing to the forming table 905, in which it is folded around of the inner tube to form an outer bag. Meanwhile, the inner tube is unwound in the unwinding units 907, and sealed with the thermal sealant 908 at fixed intervals to form the separate bags.

As the weft is folded around the inner bags, the longitudinal links of the outer bag are formed at the post 906, and then the bags are sent to the rotary transverse cutter 909 to cut and separate the individual bags containing both the internal bag as the external one. Then these individual bags are rotated in the tube rotation station 910, and subsequently they are sent to the tube alignment station, before arriving at the folding and opening station of the bottom 912.

Preferably, during the provision of hot melt adhesive at station 904, an area of adhesive is applied to what will be the internal base portion of the outer bag, so that the lower portion of the inner bag is "on" inside the bottom of the outer bag. Preferably, this occurs on only one side of the inner bag, so that it can remain properly in place during folding and forming of the block bottom of the outer bag. This small portion of adhesive helps to locate the inner bag inside the outer bag, and still should be able to be "released" so that the inner bag can be detached from the outer bag when the inner bag is removed from the outer bag at its destination.

The posts 913-915 are related to the provision of the folded block bottom in the outer bag, and with the delivery of a separate bottom patch to the bottom of each outer bag, producing a bag with folded block bottom of the type that is appreciated in Figures 2-7.

It will be appreciated that if the inner bag and the outer bag are formed of plastic materials with different seal initiation points, then it will not be necessary to have a stand for the provision of lacquer or other non-sealable layer. 802008.docJP / gg A production line like this one is suitable for the production of bags with a block bottom of T5-25 kg, since this size is suitable for the transport of milk powder, particulate chemicals and other products. food. In general, these bags have dimensions of up to 1160 mm x 600 mm.

The same type of conversion machine can be used to produce the bags of the first or third embodiment, with the addition of an appropriate station to provide the heat resistant lacquer, or a layer of thermal sealant material in the appropriate portion of the inner bag or outer bag. In addition, a similar machine could be used to provide those embodiments that use an internal plastic bag and an outer spun or paper bag. 802008 English.doc JP / gg Filling and Sealing the Bags The bags produced according to Figures 2-7 can be delivered to the end user for use in conjunction with a filling and sealing machine. A variety of filling machines can be used, depending on the needs of the user. For example, a user may use a single-head filling machine, or a multi-bag filling machine, such as an end-of-line bag filler, or a carousel bag filler.

Depending on the material with which the inner bag is to be filled, the bag filling machine may include gas washing, or vacuum packaging, to extract air from the inner bag. In some cases, it may be desirable to form the inner bag or outer bag, or both, with suitable barrier materials that prevent the ingress of oxygen, or the escape of oxygen from an internal atmosphere, if it is used in the atmosphere. filling of the inner bag.

Once the inner bags have been filled, then the filled bags can be sealed with heat. To seal the bags with heat, it is preferable that the bags go to a neck stretching post, so that the mouth of the inner bag and the outer bag is tensed to stay flat, and then be stretched before passing to the bag leveling position. In this position, the upper part of the bag is leveled and aligned so that it can pass to a thermal seal post to ensure that the thermal seal (s) is in the proper places on the bag.

In Figures 3 and 4, the width of the upper part of the bag is shown to be larger than the width of the bottom of the bag in order to exaggerate the stretching effect before the thermal seal.

At the heat sealing station, a first set of heat sealing rods grabs the bag and heat is applied to the outside of the outer bag so that the combination of heat and pressure, together with the proper choice of materials for the inner bag and externally allow only the inner bag to be heat sealed by line 205 of Figure 3. In the case of the all-plastic bag comprising an inner bag and an outer bag of 802008 English.doc / JP / gg plastic, the second set of thermal sealing bars can apply heat and pressure to the top of the inner bag and the outer bag, allowing it to be heat sealed through the four layers of material (treating the inner and outer bags as if they formed a single tube, regardless of whether or not they are made up of multiple layers of material, hence the reference to the two layers of material of the inner bag surrounded by the two layers of material of the external bag). The second set of thermal sealing bars by applying a temperature higher than that of the first set will cause both the inner and outer bags to be sealed together by heat.

At the same time, the inner bag and the outer bag can be punctured at 206, these perforations being located at a distance from the thermal seal line 205. This drilling step is desirable, but not essential. In one embodiment it is possible that the outer bag can, for example, have a printed line that coincides with the line 206, indicating where the bag should be cut or guillotined to separate the inner bag and the outer bag. If perforations are employed, it is also preferable to use a thermal perforation knife to provide sealed edges to the perforations made. This seals the entry points to the bag and will detach easily, allowing the separation of the inner bag from the outside.

Once the bags have been filled and sealed, they can be changed from vertical to horizontal position, weighed, and receive proper coding if desired. Then, preferably, the bags are passed to a flattening station, to match their contents and make the bags more rectangular in their profile, more apt for the mechanized positioning of the filled bags on the pallets.

ADVANTAGE An advantage of the preferred embodiments of this invention is that the outer bag can be opened and discarded, while the inner bag remains intact and sealed. The inner bag is not contaminated during shipment and can be taken to critical food hygiene areas after removal of the outer bag. 802008 English.doc / JP / gg It is not necessary for the end user of multi-fold packaging to keep materials as sticky if the double-seal thermal plastic bag combination is used, since both the inner and outer bag can be close by thermal sealing.

The preferred embodiments of this invention are especially suitable for the packaging and transportation of milk powder, milk powder derivatives and other food grade particulate materials. Ai package the milk powder in a double plastic bag, as described in the first preferred embodiment, or in the combination of plastic bag with paper exterior, as described in the second preferred embodiment, milk powder or other Food grade materials are packaged inside an internal polyethylene bag, which can be sealed and sealed by thermal sealing. This internal polyethylene bag is water and dust tight, thus avoiding contamination of the contents. Prototypes of the invention have been tested with milk powder products and their derivatives. It is contemplated that the invention will be suitable for the packaging of milk proteins, whole or skim milk, casein, salt, various food products, food ingredients, pharmaceuticals and other bulk products that require a bag-in-bag packaging system.

Whether the outer bag is formed of plastic, such as polyethylene, or paper, fulfills two main tasks. First, it protects the internal bag from damage and, second, it keeps the inner bag clean. In addition, the outer bag can be used for printing, and there is an additional advantage if it is an outer plastic bag, since it is easier to get high print quality in the outer plastic bag. It is also possible to use different textures of plastic material, to improve friction and thus resistance to slip, or collapse when a number of bags are stacked on a pallet. The most preferred form of this invention makes use of the double plastic bag scheme, because it allows the design of the outer bag to be controlled, both for printing purposes and for resistance to light and friction and, therefore, stackability. Furthermore, by using the double plastic bag scheme as described above, it is possible to simplify the manufacture of the bags, and even more importantly, it has the advantage of simplifying handling and closing 802008.doc / JP / gg of the bags, since in its most preferred form, the double plastic bags can be closed by thermal sealing, preferably by using two sets of sealing bars to effect closure of the inner bag in the first seal thermal, and to effect the closing of at least the outer bag in the second thermal seal, with some form of perforation, or another scheme of easy opening between the first and the second thermal seal.

VARIATIONS In the preferred embodiment, we have referred to the two-fold bags. However, the invention can be applied to bags or bags with multiple folds with three or more folds, for example bag in bag in bag.

If necessary, you can close the external package with adhesives after sealing the internal package.

Although preferred embodiments have been related to the manufacture and use of larger bags in the form of bags suitable for the transport of milk powder, containing, for example, 15 to 25 kg of product, the invention can also be used for an amount of other sizes of bags or sacks.

For example, sterile liquids could be packed in small, bulbous bags of Example 100 ml to 500 ml, as seen in Figures 13 and 14. In this scheme, the inner bag 301 is slightly smaller than the outer bag 302, both have a similar bulbous shape, with a long neck 303. Al forming the inner bag with a seal initiation material smaller than that of the outer bag, it is possible to use a differential thermal seal by the neck of the bag 303, so that a first pair of thermal sealing rods 304 can be applied to the outer bag 302 towards the bottom of the neck, and sufficient heat is applied to thermally seal only the inner bag at that point with a thermal seal resulting in line 307, while the pair of thermal seal bars 305 can operate at a temperature higher to ensure that both the inner and outer bags are sealed together on line 308. 802008 English.doc / JP / gg By providing a clear separation between the thermal seals 307 and 308, the thermal seals will be really visible if the material of both bags is transparent, as is desirable for the transport of sterile liquids, thus it will not be It is necessary to perforate or mark the neck of the bag to indicate where it should be cut between the two stamps 307 and 308. However, the outer bag could be overprinted with the reading indicating that it should be cut between the thermal seal lines, or it could be Place a colored band on the neck of the bag between the two thermal seals, with an indication on the outer bag that the neck of the bag should be cut in the colored strip to separate the inner bag and the outer bag.

A similar scheme could be used for the vacuum packaging of food products, such as poultry, cheese, fruit or vegetables, where a longer duration, or longer transport requirements make it desirable for the food to be packaged with a "bag" method. in a bag".

Many other variations are possible. It is for this reason that the analysis of Figure 1 only showed the neck of the package rather than the shape, or the base of the bag, to emphasize the inventive feature of the "bag in bag" system, allowing the sealing of the inner bag it is different from the sealing of the outer bag, at least in the first thermal seal. 802008.doc / JP / gg Table 1 Table 1 shows several of the different options where the marks of a column represent the characteristics applicable to a particular option. For example, option 1 'uses a lacquer to avoid sealing between the outer surface of the inner fold and the inner surface of the outer fold, whereas Option 2 prevents the sealing of outer folds by using sealants with different coefficients of temperature.

Explanation of the options in the table: 1. Double seal with lower seal on non-sealable coating of reverse lacquer heat, perforation between the two seals. It allows the manufacture of a bag that takes advantage of the simplest plastic films. The closure design is functional due to the lacquer that is applied. It involves the cost of the lacquer application and has another variable to control during manufacturing. 802008 English.doc JP / gg 2. Double thermal seals made by a sealant design with individual control of the process variables, temperature; Interval time and pressure, to seal materials with differential sealing. Lower seal to close the inner tube with low temperature sealant on the internal faces. Upper seal that operates at higher parameters to seal more difficult material. Piercing between the seals.

It offers lower material costs than those of simplified bag making. Increased investment in film extrusion equipment. 3. As in option 1 or 2, or alternatively using incompatible thermoplastics, that is, polyethylene with polyamide. The lower seal effects the closing of the internal tube, the upper seal position is not used, but the outer package is closed by the use of an adhesive tape. A bag like 1, but using alternative means of closure of the outer bag. This would be useful for customers who would not accept an outer bag with a row of perforations. It leads to a disadvantage in that the customer requires additional closure equipment to apply adhesive tape and needs to store a consumable product with its added cost. 4. A hybrid of 2 and 3, eliminating the need for lacquer applied in the manufacture of the bag. It goes through the disadvantages of 2 and 3.

. A variant of 4, where there is an incompatible polymer on a surface of the folds of the bag. This could be on the inner surface of the outer bag or on the outer surface of the inner bag. Increase the total costs of the movie. 6. A variant of 1, which takes advantage of the characteristics of option 1 and adds an adhesive tape applied to the row of perforations. It involves the additional costs of closure equipment and consumable product of option 3. 7. A variant of 2, like 6 is a variant of 1. 802008 English.doc / JP / gg 8. A variant of 2 that uses a thermal perforation knife to seal the edges of the perforations made. The foregoing is to offer total exclusion of external contaminants. 9. A variant of 1, like 6 is a variant of 2.

It will be appreciated that various changes could be made to the above examples without departing from the general scope of the invention, as set forth in the claims. 802008.doc / JP / gg

Claims (14)

1. Packaging, including an inner bag with an inner surface and an outer surface, surrounded by an outer but removable bag, with an inner surface and an outer surface, each bag with a closed base and each bag with an upper opening, wherein the inner surface of the mouth of the inner bag has a heat-sealable area, and the inner surface of the mouth of the outer bag has (a) a non-heat sealable zone corresponding to the location of the sealable area at heat of the inner bag, and (b) a sealable area between the non-heat sealable area and the top of the bag, so that in use, a heat sealing operation can be performed through the outer bag to create a first seal capable of closing and sealing the mouth of the inner bag without sealing the outer bag in that non-heat-sealable area, and that a sealing operation can be performed at least on the outer bag to create a second seal that close and seal the outer bag in its sealable area to enclose the sealed inner bag inside the outer bag.

2. Packaging according to claim 1, wherein the second seal is adapted to seal the inner and outer bags together.

3. Packaging according to claim 2, wherein the sealable area of the outer bag is adapted for thermal sealing.

4. Packaging according to claim 3, wherein a non-sealable layer is provided on the outside of the inner bag, or on the inside of the outer bag in the region of the non-sealable area of the outer bag.

5. Packaging according to claim 4, wherein the non-sealable layer is chosen from the group including, but not limited to, solvent based lacquer lacquers, water lacquer lacquers and silicone dispersions.

802008.doc / JP / gg 6. Packaging according to claim 1, wherein the inner bag and the outer bag are made of different materials.

7. Packaging according to claim 6, wherein the inner bag is a plastic bag with a thermal seal temperature lower than that of the outer bag material.

8. Packaging according to claim 7, wherein the inner bag is formed of polyethylene.

9. Packaging according to claim 8, wherein at least the inner surface of the outer bag is formed of plastic material.

10. Packaging according to claim 9, wherein the inner surface of the outer bag is formed of polyethylene with a thermal sealing temperature greater than that of the material of the inner bag.

11. Packaging according to claim 10, wherein the outer bag is formed of laminated polyethylene, or paper coated in polyethylene or spun polypropylene coated in polyethylene.

12. Packaging according to claim 1, in the form of a bag, wherein the outer bag has a block base, and the base of the inner bag is removably attached to the bottom of the outer bag.

13. Packaging according to claim 12, wherein the outer bag has gripping means on the bottom of it, so that in use, a user can grab the bottom of the bag to facilitate the removal of the inner bag and its contents from the bag extema

14. A packaging filling and sealing method of the type according to claim 1, with an inner bag surrounded by an external but removable bag, wherein the package is supplied to a filling machine until the inner bag is filled 802008.doc / JP / gg to the desired amount, the mouth of the bag is stretched to flatten the inner bag and extend it into the region of the first and second sealing zone, the inner bag is sealed by the first sealing area to create a first seal without adhering to the outer bag, and the outer bag and inner bag are sealed together in the region of the second sealing zone to create a second seal. A method according to claim 14, wherein a frangible zone is provided between the sealable area of the outer bag and the non-sealable zone of the outer bag. A package comprising packaging according to claim 1, has a full inner bag, surrounded by an external bag, but removable from it, the inner bag is closed by a first thermal seal, but the outer bag is not thermally sealed to the inner bag in at that point, the outer bag is closed by a second seal located between the first seal and the upper part of the bag, and there is a frangible zone located between the first and second seal, so that in use, the outer bag can be removed of the sealed inner bag by cutting or tearing the frangible zone. A package according to claim 16, wherein the frangible zone is formed by perforations extending through the inner bag and the outer bag. A method of emptying a package according to claim 17, wherein the second seal is removed by tearing or cutting along the frangible zone between the first and second seal, and the fully sealed inner bag is removed from the outer bag. A package according to claim 16, wherein the filled inner bag contains a milk powder product or a milk powder derivative. papish.doc / JP / gg