DESCRIPTION

Technical field

The present invention relates to a multi-layer bag package, particularly designed to contain a product that may be in liquid, semiliquid, powder, granular, noncohesive form, or derive from a mixture of multiple components, each in one of these states, according to claim 1.

This package is particularly suitable for storage of products in food and chemical processing industry or, more generally, for packaging products that need to be protected from foreign agents, such as atmospheric oxygen and humidity.

The present invention also relates to a continuous tubular element for making such package.

Background art

Large industrial gusseted bags (generally for 3-25 kg) for packaging products are widely known in the art. These bags are formed from a multilayer laminated web. Typically, this web comprises a sealing inner layer, made of polyethylene, low density polyethylene (LDPE), polypropylene and the like. This inner layer is intended to contact the product to be packaged during use.

The inner layer is combined with a more rigid outer layer which may be made of nylon (biaxially oriented or not), and the like. An intermediate layer, for example made of polyester or metallized polyester, is arranged between the outer layer and the inner layer and entirely adheres thereto.

In use, the multi-layer bag packages as discussed above are handled by pallets and stored by stacking them one on top of the other.

Examples of packages of the aforementioned type are disclosed in US 2018/072463 Al and US 2012/269466.

Problem of the prior art

Undesirably, during handling and stacking, such packages are often prone to tearing, due to the presence of air inside the bag that can cause the package to break under squeezing pressure.

Object of the Invention

Therefore, the technical purpose of the present invention is to provide a multilayer bag package that can obviate the aforementioned prior art drawbacks.

In particular, one object of the present invention is to provide a multilayer bag package that can limit the risk of tearing.

A further object of the present invention to provide a multilayer bag package that can limit product losses, even as a result of accidental tearing.

One more object of the present invention to provide a package that can keep or improve tightness, by improving tear resistance.

The aforementioned technical purpose and objects are substantially achieved by a multilayer bag package formed from a continuous tubular element as defined in claim 1.

Advantages of the invention

In particular, this continuous tubular element is defined by a continuous web of multilayer material extending in a longitudinal direction and a longitudinal sealing region substantially parallel to the longitudinal direction.

The web comprises:

- an inner layer made of a heat-sealable material adapted to contact the products to be stored;

- at least one intermediate layer at least partially adhering to the inner layer;

- an outer layer adhering to the intermediate layer. The web also has at least one partial non-adhesion zone between the inner layer and the intermediate layer. The partial non-adhesion zone is defined by a plurality of distinct non-adhesion areas, in which the inner layer does not adhere to the intermediate layer.

A package according to the present invention comprises an enclosure formed from a section of a continuous tubular element as defined in claim 1. The enclosure is defined by a pair of cutting lines that are transverse, an in particular perpendicular to the longitudinal direction along which the web extends.

The enclosure has a bottom defined by a first transverse sealing zone located at a first cutting line and a top defined by a second transverse sealing zone located at a second cutting line. The enclosure is hermetically sealed by the transverse sealing zones and the longitudinal sealing zone.

The above-described package solves the technical problem. The presence of partial non-adhesion zones imparts additional puncture resistance and hence reduces the possibility of tearing upon puncturing. Furthermore, even when the enclosure is actually torn, tear propagation is stopped when it encounters a non-adhesion area. Therefore, the tear will remain of smaller size, thereby limiting product losses.

Finally, it should be noted that, since the non-adhesion areas are distinct and separated by a full-adhesion area, air cannot enter the enclosure through the outer edges. Thus, the tightness of the package will remain unaffected.

Brief description of the figures

Further features and advantages of the present invention will result more clearly from the illustrative, non-limiting description of a preferred, non-exclusive embodiment of a multilayer bag package as shown in the annexed drawings, in which:

- Figure 1 is a perspective view of a first embodiment of a multilayer bag package of the present invention; - Figure 2 is a plan view of a multilayer web that is used to form the package of Figure 1;

- Figure 3 is a perspective view of a second embodiment of a multilayer bag package of the present invention;

- Figure 4 is a plan view of a multilayer web that is used to form the package of Figure 3;

- Figure 5 is an enlarged view of a detail of the webs of Figures 2 and 4;

- Figure 6 is a sectional schematic view of the webs of Figures 2 and 4; and

- Figure 7 is a schematic view of a tubular element for making the packages of Figures 1 and 3.

DETAILED DESCRIPTION

Referring to the annexed figures, numeral 1 designates a multilayer bag package of the present invention.

As used herein, “bag” refers to a flexible and/or deformable enclosure designed with the function of containing a product which may be in liquid, semiliquid, powder, granular, non-cohesive form, or derive from a mixture of multiple components, each in one of these states.

The package 1 has been designed to contain products from the chemical or food processing industries but may also be intended for different uses.

First of all, it should be noted that the package 1, comprising an enclosure 2, is formed from a tubular element 100, defined by a multilayer web 101 as schematically shown particularly in Figure 7.

The tubular element 100 extends continuously, which means that its length is much greater than its width, to provide a large number of packages 1 from a single tubular element 100 by means of a continuous process.

The process of forming packages 1 from the tubular element 100 is well known to the skilled person and will not be further described below. It should be noted that, since the package 1 is directly derived from the tubular element 100, the characteristics that will be discussed with reference to the web 101 are understood to equally refer to the package 2 where applicable and, for this reason, corresponding elements on the web 101 and on the enclosure 2 will be referenced below with the same numeral.

Referring now to Figures 2 and 4, it should be noted that the web 101 continuously extends along a longitudinal direction “A”. A longitudinal sealing zone 9 is substantially parallel to the longitudinal direction “A” and joins two opposite edges 102 of the web 101.

The web 101 comprises an inner layer 3, which is adapted to contact the product to be stored in the package 1, for example food. The inner layer 3 is adapted to be sealed or heat-sealed, and can be made, for example, of linear polyethylene (LLDPE), low density polyethylene (LDPE), cast polypropylene and the like, preferably polyethylene or polypropylene.

The web 101 further comprises at least one intermediate layer 4, which namely partially adheres to the inner layer 3. In particular, the intermediate layer 4 is bonded by adhesive to the inner layer 3. This intermediate layer 4 can be made of aluminum, polyester, nylon (biaxially oriented or not) or other materials already known to the skilled person.

An outer layer 5 adheres to the intermediate layer 4. The outer layer 5 is designed to withstand the aggressive action of atmospheric and environmental agents such as, for example, oxygen and humidity, to isolate and preserve the contents of the package 1. For example, the outer layer 5 can be made of polyethylene (PE), polypropylene (PP), polyamide/nylon (PA) or polyester (PET).

It should be noted that, in alternative embodiments, not shown herein, the web

101 may comprise any number of additional intermediate layers arranged between the intermediate layer 4 and the outer layer 5.

The thicknesses of the layers 3, 4, 5 that make up the web 101 are not limited for the purposes of the present invention, but the inner layer 3 is typically thicker than the remaining layers. In a preferred embodiment, the inner layer 3 has a thickness that ranges from 100 to 200 microns, the intermediate layer 4 has a thickness that ranges from 6 to 30 microns, whereas the outer layer 5 has a thickness approximately ranging from 10 to 50 microns.

Particularly referring to Figures 2 and 4, it should be noted that the web 101 has at least one partial non-adhesion zone 6 between the inner layer 3 and the intermediate layer 4. This partial non-adhesion zone 6 is defined by a plurality of distinct non-adherence areas 7.

In each non-adhesion area 7, the inner layer 3 does not adhere to the intermediate layer 4. Advantageously, this partial lack of adhesion can prevent and/or limit tearing.

More in detail, it should be noted that the non-adhesion areas 7 of each non- adhesion zone 6 are closed. The non-adhesion areas 7 are further separated by an adhesion area 8, in which the inner layer 3 fully adheres to the intermediate layer 4. The adhesion area 8 of each partial non-adhesion zone 6 is continuous, which means that two arbitrary points in the adhesion area 8 can be connected by at least one path that does not intersect any non-adhesion area 7. Advantageously, this prevents outside air from entering the package 1 once the latter has been closed and sealed.

It should be noted that the distance between each pair of adjacent non-adhesion areas 7 is at least 0,5 mm.

Referring to Figures 2 and 4, it should be noted that the web 101 has at least one pair of full -adhesion zones 10, in which the inner layer 3 of the web 101 fully adheres to the intermediate layer 4. These full-adhesion zones 10 are formed substantially at the sides and along the entire length of the web 101 and extend parallel to the longitudinal direction “A”. In other words, the full-adhesion zones 10 are in the form of uniform longitudinal stripes. The full-adhesion zones 10 are joined together during processing, to define the longitudinal sealing zone 9 of the tubular element 100. Advantageously, the use of full-adhesion zones 10 for this purpose imparts greater stiffness to the longitudinal sealing zone 9.

Optionally, as shown in Figures 1 and 2, an additional full-adhesion zone 11 may be formed at the center of the web 100, preferably but not necessarily equidistant from the full-adhesion zones 10 and having a similar shape. Advantageously, the additional full-adhesion zone 11 permits a valve 12, known per se, to be installed on the enclosure 2. In particular, the valve 12 is inserted into the additional full-adhesion zone 11.

It should be noted that, if the additional full-adhesion zone 11 is present, as shown in the embodiment of Figure 2, the web 101 has two partial non-adhesion zones 6, each arranged between a respective full-adhesion zone 10 and the additional fulladhesion zone 11. When the valve 12 is not necessary, the additional full-adhesion zone 11 can be omitted. Here, as shown in Figure 4, the web 101 will have a single partial non-adhesion zone 6 arranged between the full-adhesion zones 10.

Particularly referring to Figures 1 and 3, which show respective exemplary packages 1 of the present invention, it should be noted that the aforementioned package 2 is formed by a section 103 of a continuous tubular element 100. In particular, the enclosure 2 is defined by a pair of cutting lines 13, that are transverse, and in particular perpendicular to the longitudinal direction “A” along which the web 101 extends. At the cutting lines 13, the web 101 is sealed, thus defining first 14 and a second 15 transverse sealing zones.

More in detail, the enclosure 2 has a bottom 16 defined by the first transverse sealing zone 15. The enclosure 2 also has a top 17, defined by the second transverse sealing zone 14. It should be noted that the enclosure 2 is hermetically sealed by the transverse sealing zones 14, 15 and the longitudinal sealing zone 9.

In the illustrated embodiment, the non-adhesion areas 7 have a circular shape, and their characteristic dimension corresponds to the diameter. Preferably, each non- adhesion-area 7 has a diameter of 0.5 to 30 mm.

In alternative embodiments, not shown, the characteristic dimension corresponds to the maximum extent of the non-adhesion area 7 along the longitudinal direction “A”. As shown in Figures 1 and 3, the enclosure 2, once completed, substantially has the shape of a parallelepiped, and particularly has a front wall 18, a rear wall 19 and two side walls 20. A pair of longitudinal folds 21 are each arranged on a respective side wall 20, namely in a substantially central position. The longitudinal folds 21 extend substantially parallel to the longitudinal direction “A”.