BAG- OR SACK-LIKE PACKAGING AND PROCESS FOR MANUFACTURING BAG- OR SACK-LIKE PACKAGING

Abstract

The present invention relates to bag- or sack-like packaging provided with a body (10) formed by a film of polymeric material and provided with at least one layer (20) composed at least in part of raffia, the layer (20) being welded to the body (10), the packaging thus promoting easy, efficient recycling, and improved palletization and storage, and allowing the automation of the manufacturing process.

Claims

1-9. (canceled)

10. A bag- or sack-type packaging comprising: a body (10) made of a polymeric material film, the body (10) not containing a synthetic compound that forms an interwoven fabric; and at least one cover (20) comprising, at least in part, a synthetic compound that forms an interwoven fabric, the cover (20) being attached to the body (10) by welding, the cover (20) comprising an outer layer (22) composed at least in part of the synthetic compound that forms the interwoven fabric and at least one inner layer (21) composed of a polymeric material weldable to the body (10).

11. The bag- or sack-type packaging according to claim 10, wherein the packaging is provided with an intermediate film (30) formed by at least a first and a second layers (31, 32) attached to each other, the first layer (31) comprising a polymeric material weldable to the body (10) and the second layer comprising polymeric material weldable to the cover (20).

12. The bag- or sack-type packaging according to claim 10, wherein the body (10) film is composed predominantly of polyethylene, the raffia in the cover (20) being composed of polyethylene.

13. The bag- or sack-type packaging according to claim 10, wherein the inner layer (21) is composed at least partially of polyethylene.

14. The bag- or sack-type packaging according to claim 10, wherein the body (10) film is composed predominantly of polyethylene, the raffia of the cover (20) being composed of polypropylene.

15. The bag- or sack-type packaging according to claim 11, wherein the first layer (31) is composed of polyethylene, the second layer (32) comprising a mixture of polyethylene and polypropylene.

16. A process for manufacturing a bag- or sack-type packaging as defined in claim 10, the process comprising the steps of: laminating a cover (20) comprising raffia; and welding the cover (20) on a body (10).

17. The process according to claim 16, wherein: the raffia of the cover (20) comprises polypropylene and the body (10) comprises predominantly polyethylene, and the process further comprises the step of welding an intermediate film (30) provided with at least a first and a second layers (31, 32) to the body (10) and the cover (20).

18. The process according to claim 17, further comprising the steps of: welding a first layer (31) comprising polyethylene to the body (10); and welding a second layer (32) comprising at least in part polypropylene to the cover (20).

Description

BRIEF DESCRIPTION OF THE FIGURES

[0030] The present invention will be described in more detail based on an exemplary embodiment represented in the drawings. The figures show:

[0031] FIG. 1is a perspective view of the packaging of the present invention;

[0032] FIG. 2is a perspective view of the packaging of the present invention with one of its ends folded and closed by a cover;

[0033] FIG. 3is a schematic representation of a preferred composition of the packaging cover of the present invention;

[0034] FIG. 4is a schematic representation of a preferred composition of the packaging of the present invention; and

[0035] FIG. 5is a schematic representation of an alternative composition of the packaging of the present invention.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

[0036] The present invention refers to a bag- or sack-type packaging whose composition of elements allows them to be automatically attached to each other by welding without using glue, giving advantages according to the objects of the invention.

[0037] For a better understanding of the present invention, the term raffia should be understood as a synthetic compound that forms an interwoven fabric. Commonly, raffia comprises a polyethylene or polypropylene fabric, or even a mixture of both. Nevertheless, the present invention can be carried out using raffia comprising other polymers or polymer mixtures without harming or altering the proposed technical effect.

[0038] FIGS. 1 and 2 illustrate the package of the present invention in its preferred upright and lying configurations with folded ends, respectively. The packaging essentially comprises a body 10 formed by a polymeric film and able to receive the material to be stored. Preferably, such a body 10 comprises a thin wall, or film, which delimits an inner region where the material will be stored. The body 10 can comprise a cylindrical, rectangular, or any other shape suitable for receiving and storing material.

[0039] Preferably, the body 10 comprises a film of at least one layer of polymeric material that can receive and store material, exhibiting good mechanical strength and imposing no risk of contamination of its contents. In a particular embodiment, the body 10 is composed predominantly of polyethylene.

[0040] For a better understanding of the invention, the term predominantly should be understood as an amount of polyethylene greater than 50% of the body 10 volume. Polyethylene distribution in the body 10 can be made in various ways, it can be entirely made of polyethylene, or even have one or more sleeves (inner layers) made of polyethylene, or even outer polyethylene layers adjacent to layers made of other polymers.

[0041] In another particular construction, the body 10 can be composed of more than 60% polyethylene, or even more than 70% polyethylene, or even more than 80% polyethylene, or even more than 90% polyethylene. The greater the minimum polyethylene limit used in the body 10 composition, the greater the body 10 flexibility, thus justifying different limit ranges for applications that require more or less flexibility of the packaging of the present invention.

[0042] In another particular embodiment, the body 10 may be composed entirely of polyethylene, or even a mixture of polyethylene and polypropylene. The body 10 can also be comprised of multiple layers forming its film, wherein each layer can also be a mixture of polyethylene, polypropylene or a mixture thereof and can also contain additives. The additives used can be of several types, such as pigments, flow auxiliaries, antioxidants and other materials to aid in the manufacture process and/or to promote better welding performance.

[0043] In a particular construction of the present invention, the body 10 can comprise at least one opening 11. In general, such an opening 11 is a result of the manufacture process commonly used to produce sacks, which consists of printing a film of a material that forms the body 10 with the inner region that will receive the material being delimited. As an example, mention can be made of printing a cylinder made of polyethylene/mixture of polyethylene and polypropylene which will thereafter generate a cylindrical packaging. The opening 11 ends can be folded on themselves as seen in FIG. 2, to form a preliminary closure and facilitate the final closure, as will be seen below.

[0044] Essentially, the package comprises at least one cover 20 made of raffia, the cover 20 being attached to the body 10 by welding. This feature of the invention addresses the problem of the state of the art that the attachment of covers on the package body requires the use of glue for an acceptable attachment, which affects recycling of the packaging. This feature also addresses the issue of the difficulty in automating the process of attaching the cover 20 to the body 10 by gluing due to the complex automation of the application of glue on the fold without impairing its stability. To solve this problem, the present invention provides a cover 20 welded to the body 10.

[0045] For a better understanding the present invention, the term welding should be understood as the process of joining two polymers by applying heat at their interfaces and subsequently heating to join their surfaces. Heating is carried out until the point of softening of the material to be welded. It should be understood here that welding is different from fusion. In welding the material is adhered in solid state and in fusion the materials are anchored to each other in liquid state and are joined together upon solidification.

[0046] Construction of the packaging of the present invention using a cover 20 welded to the body 10 provides an advantageous end palletizable shape of the packaging (in general, substantially rectangular and suitable for stacking, transport and storage, either on pallets or not) without the need for using glue, thus allowing easy storage and transport and easier and more efficient recycling of the packaging. In addition, the present invention also eliminates the difficulties in automating the process of gluing the cover to the body, allowing automatic welding (a much more stable attachment process) of the cover to the body.

[0047] However, welding the cover 20 to the body 10 of the packaging of the invention is not sufficient to achieve the technical effects proposed by the invention. If a cover 20 made of a polymer film is welded against a body 10 also made of a polymer film, several problems arise depending on the material used. For example, in more flexible polymers (such as polyethylene) having low weldability (ease of performing the welding operation), as they comprise, for example, a very low softening temperature and welding of a thin film cover over the fold results in deformation (wrinkling) of the cover resulting in poor closure.

[0048] On the other hand, the use of polymers having greater weldability (such as polypropylene) in general does not meet the strength and flexibility requirements of a sack-type packaging, that is, the final packaging cannot be used in many of the required applications for this type of packaging, such as transporting heavy weights and constant handling by people and machines.

[0049] Thus, the packaging of the present invention further comprises the cover 20 being composed of raffia. Raffia fabric has an interwoven structure that provides it with greater weldability, even though raffia is composed of materials that originally exhibit low weldability, such as polyethylene. Thus, the cover 20 can be welded to the body 10 film without deforming said cover 20.

[0050] Thus, the cover 20 made of raffia and welded to a body 10 formed by a film of polymeric material provides a packaging that does not require the use of glue, can be easily manufactured in an automated manner, the cover can be welded to the body without being deformed, and has a favorable shape for storage and palletization.

[0051] In a particular construction of the package, as seen in FIG. 2, the covers 20 can be welded to one or both longitudinal ends of the body 10 where the openings 11 are located to allow closure of the package, even though the cover can be attached to other regions of the body 10. In particular, the cover 20 is attached to the body 10 at each of its longitudinal ends, over the openings 11. In a possible embodiment of the body 10, more than one cover 20 is attached to the body 10 to cover multiple regions of interest, such as, for example, one cover 20 for each of the openings 11.

[0052] In a preferred embodiment of the cover 20 of the present invention, shown in FIG. 3, the cover 20 comprises an inner layer 21 and an outer layer 22. For a better understanding of the cover 20 construction in such a preferred embodiment, the inner layer 21 consists of the layer that is in contact with and is welded to the body 10 film, while the outer layer 22 is the one facing the external environment and is arranged on the opposite side with respect to the inner layer 21.

[0053] The outer layer 22 is particularly composed at least partially of raffia, and the inner layer 21 is composed of any polymer material, or a mixture of polymeric materials. Preferably, the inner layer 21 is a lamination layer, which aids in welding the cover 20 to the body 10. The inner lamination layer 21 can be applied to the outer raffia layer 22 by means of a polymeric lamination process, where a melted polymer is drained over the outer raffia layer 22 forming the inner layer 21. In particular, the lamination layer is composed of the same polymeric material as the inner layer 21, and it can also be a mixture of polypropylene or polyethylene, or even polyethylene alone, polypropylene alone or other materials such as EVA (ethylene and vinyl acetate copolymer).

[0054] FIG. 4 shows a preferred embodiment of the attachment between the cover 20 and the body 10. The inner layer 21 is arranged adjacent the body 10. In this preferred embodiment, the inner layer 21 of the cover 20 is the one that will be welded to the body 10 and, therefore, there must be chemical parity between the layer 21 and body 10 materials to enable welding attachment. As previously explained, the body 10 is preferably composed of a film made predominantly of polyethylene, such that layer 21 should preferably comprise polyethylene. In this preferred embodiment, the raffia cover 20 comprises polyethylene in order to enable chemical parity between the inner and outer layers 21, 22 during the lamination process.

[0055] In an alternative embodiment of the present invention shown in FIG. 5, the package comprises an intermediate film 30 provided with at least a first and a second layers 31, 32. This alternative embodiment is particularly applicable in instances where the raffia cover 20 is composed of a material that does not exhibit chemical parity with the body 10 material, and in such an instance, even using the laminated inner layer 21, a reliable welding attachment would not be possible.

[0056] Thus, the intermediate film 30 acts to aid in chemical parity between the the cover 20 and body 10 materials, the first layer 31 being weldable to the body 10 and the second layer being weldable to the cover 20. More particularly, the second layer 20 is weldable to the inner layer 21 of the cover 20.

[0057] More particularly, preferably, but not obligatorily, the intermediate film 30 comprises a thickness ratio of 20%, 80%, respectively, relative to the sum of thicknesses of these two layers. Even more particularly, the inner layer comprises, preferably, but not obligatorily, a ratio of 15% to 40% polyethylene and 60% to 85% polypropylene or vice versa depending on the film material of the sack body.

[0058] In a possible construction of this alternative embodiment, the outer 22 and inner 21 layers of the cover 20 are composed of polypropylene raffia and polypropylene, respectively, and the body 10 is predominantly composed of polyethylene. The intermediate film 30 is then formed by a first layer 31 made of polyethylene, allowing it to be welded to the body 10, and the second layer 32 is composed of polypropylene or a mixture of polyethylene and polypropylene, which allows it to be welded to the inner layer 21 of the cover 20. Welding the intermediate film 30 to the body 10 and the cover 20 provides a package that achieves the objects proposed by the present invention, even when the cover 20 and body 10 materials do not exhibit chemical parity.

[0059] It is further clarified that the cover 20 of the present invention may comprise any number of inner layers 21 with any composition of polypropylene, polyethylene or a mixture thereof, depending only on the intended application, provided that the arrangement and composition of the layers allow the attachment of the cover 20 to the body 10, either using the intermediate film 30 or not.

[0060] In addition, the intermediate film 30 can also comprise any number of layers, not just a first and a second layers. The number of layers of the intermediate film 30 will depend on the type of intended application and on other functions to be fulfilled thereby, besides enabling welding between the cover 20 and the body 10, such as the function of filling the packaging film or thermal insulation. For such functions, additional layers can be used in the intermediate film without affecting its proposed function.

[0061] In a particular embodiment of the present invention, the body 10 is attached to a valve 30. As seen in FIGS. 1 and 2, the valve 30 is attached to the body 10 through one of its openings 11, and is intended to allow the filling and subsequent closing of the package.

[0062] In particular, the valve 30 comprises raffia and is welded to the body 10, achieving the same benefits of welding the raffia cover 20 onto the body 10. In this case, the valve 40 must have a composition that would allow it to be welded to the body 10, either using an intermediate film 30 or not, as is done for the cover 20. In a possible construction, the valve 40 may comprise an outer layer 42 composed of raffia and an inner layer 41 composed of a polymer weldable to the body 10, or to one of the intermediate film 30 layers. As with the cover 20, the valve 40 can be composed of multiple inner layers depending on the desired application.

[0063] The layer arrangement shown in FIGS. 3, 4 and 5 can be applied not only to the cover 20, but also to the valve 40. According to the preferred embodiment of the body 10 composed predominantly of polyethylene, the inner 41 and outer 42 layers of the valve 40 are composed of polyethylene and polyethylene raffia, respectively. In an alternative embodiment where the raffia valve 40 comprises a material exhibiting no chemical parity with the body 10 material, an intermediate film 30 is used, having a first layer 31 of a material weldable to the body 10 and a second layer 32 of a material weldable to the inner layer 41 of the valve 40.

[0064] In accordance with the bag- or sack-type packaging described above, the present invention also refers to a process for the manufacture of this packaging, essentially comprising the steps of: [0065] laminating a cover 20 comprising raffia; and [0066] welding the cover 20 on a body 10.

[0067] Lamination of the cover 20 composed of raffia consists of adding the inner layer 21 by polymeric lamination, as previously discussed. Welding of the cover 20 to the body 10 is carried out by heating the region between the body 10 and the cover 20 and subsequently arranging them in contact with each other. Also, as already discussed, such welding process can be automated.

[0068] For instances where the cover 20 comprises a material having no chemical parity with the body 10 material, the process can particularly further comprise the following step: [0069] welding an intermediate film 30 provided with at least a first and a second layers 31, 32 to the body 10 and the cover 20.

[0070] Even more particularly, the process further comprises the following steps: [0071] welding a first layer 31 comprising polyethylene to the body 10; [0072] welding a second layer 32 comprising at least in part polypropylene to the cover 20.

[0073] The aforementioned process further comprises the characteristics of the already described materials, such as the fact that the intermediate film 30 comprises a thickness ratio of 20%, 80%, respectively, relative to the sum of thicknesses of both layers. Even more particularly, the inner layer comprises, preferably, but not obligatorily, a ratio of 15% to 40% polyethylene and 60% to 85% polypropylene or vice versa depending on the film material of the sack body.

[0074] Having described a preferred exemplary embodiment, it should be understood that the scope of the present invention covers other possible variations, being limited only by the content of the appended claims, including possible equivalents thereof.