EA006042B1 - A tubular element for the formation of bags for the vacuum packaging of products - Google Patents

Abstract

A tubular element (1) for forming bags (14) for the vacuum packaging of products (17), particularly perishable products, comprises one or more walls (2) which are impermeable to gases and at least one dividing sheet (3) substantially impermeable to liquids and interposed between the walls (2). The walls (2) and the dividing sheet (3) are connected along longitudinal sides (4) to form a tubular body with two or more chambers (5, 5'), each chamber (5, 5') being at least partially delimited by the dividing sheet (3). The dividing sheet (3) comprises a continuous, liquid-tight, central layer (12) from which projections (8) extend into both adjacent chambers (5, 5'), the projections (8) defining, together with regions (13) of the surfaces of the central layer (12), a system of suction channels (9).

Description

The technical field to which the invention relates.

The object of the present invention is a tubular element for forming impermeable bags suitable for heat sealing or welding, and used in vacuum packaging of products, in particular, perishable foodstuffs.

The level of technology

Prefabricated elements for the indicated application are known. They are formed by one or two walls of synthetic material, welded along the longitudinal sides to form a continuous pipe. Packages can be formed from such a tube by transverse cutting and sealing the corresponding holes by welding.

Synthetic materials, impermeable to gases, but at the same time suitable for thermal soldering and for contact with food, are still unknown. Therefore, the walls have to be formed by two superimposed and tightly connected layers, of which the outer layer is impermeable to gases, and the inner one is suitable for contact with food products and has the ability to thermally solder or weld.

In order to prevent the walls from deforming with the product fitting during the pumping out of the bag, leading to the formation of isolated non-pumped zones, the inner surface of at least one of the walls has protrusions or thickenings forming the exit channels. On these channels air is removed from the isolated zones.

However, such a solution to the problem requires an increased consumption of material, since the walls have an uneven thickness, and their strength is determined mainly by the most weakened sections.

In the patent document EP 0216327 described package, in which the output channels formed by protrusions and depressions, obtained by co-profiling two layers or by corrugating the inner layer with the subsequent connection of the layers on their surfaces.

Both the joint profiling of two layers and the joining of smooth and corrugated layers along their surfaces include complex and, therefore, expensive operations. In addition, during their holding air inclusions can form between the two layers. After pumping the bag, this air penetrates through the inner layer and contributes to the deterioration of the product quality.

An alternative solution is proposed in patent document EP 0648688, according to which a plurality of parallel threadlike elements are connected to the inner side of a two-layer wall, and the output channels for air are determined by the space between these elements.

However, the advantage of two-layer walls, which in the initial state are smooth and, therefore, inexpensive, is brought to nothing by the difficulties in installing and fixing the thread-like elements on the surface. If these elements are installed incorrectly in the transverse direction, they can create a barrier to pumping out, which makes the package unusable.

In the patent document EP 0749912 a bag is described in which the threadlike elements are replaced with a perforated sheet dividing the bag into two compartments. One of them contains the product, and the other is the exhaust chamber. In the process of creating a vacuum, the air passes through the perforations of the sheet from the compartment containing the product to and from the second compartment to the external environment.

In addition to the high resistance shown by the perforated sheet in relation to pumping, the system described in this document has another drawback. It lies in the fact that during the pumping out of the packaged product, such as meat juice, passes through the perforation holes, not allowing the pumping out completely and giving the package an untidy look.

In addition to the specific drawbacks inherent in each solution of the problem described above, according to the state of the art, all the packages known so far, designed for vacuum packaging of perishable (especially food) products, have the disadvantage that several different products cannot be stored in them. In fact, during the creation of a vacuum, co-packaged differing products will contaminate each other. It is also possible that the labels and labels inside the packages are contaminated, for example, by substances derived from the product, in particular, meat juices.

Finally, due to its plasticity, the walls tend to bend under the influence of vacuum, thus blocking the exit channels. For all currently existing systems, attempts are being made to prevent these problems by limiting the distance between the bulges and strengthening the walls and bulges. However, all this does not lead to satisfactory results, but only to excessive consumption of material.

Summary of Invention

Thus, the problem to which the present invention is directed is to develop a system designed for vacuum packaging of products and characterized by the absence of the indicated disadvantages characteristic of the current level of technology.

This task, as well as a number of other tasks are solved by, first, a tubular element made in accordance with claim 1 of the claims and intended for forming packages, and secondly, a package made using such an element.

- 1 006042

For a better understanding of the invention, variants of its implementation will be described below using an example that is not restrictive, and with reference to the accompanying drawings.

List of drawings

FIG. 1 illustrates a cross section of a tubular element for forming a package according to the invention.

FIG. 2 is an enlarged view of region II shown in FIG. one.

FIG. 3 is a sectional view of a fragment of an embodiment of the invention.

FIG. 4a-4e illustrate possible embodiments of a fragment of a tubular element, presented in cross section and in a plan view.

FIG. 5 and 6 illustrate cross sections of other embodiments of the invention.

FIG. 7 illustrates a possible method of siphoning and sealing the bag, which is made using the tubular element shown in FIG. one.

FIG. 8a, 8b represent a schematic depiction of changes in the configuration of a package known from the prior art, and a package according to the invention under the influence of a vacuum.

FIG. 9 is a schematic depiction of the overflow of air enclosed in a bag according to the invention.

Information confirming the possibility of carrying out the invention

The tubular element for forming packages intended for packaging products is designated generally as 1. This element is formed by two continuous sheets or strips forming walls 2 and a separating sheet 3, which is a continuous sheet or a continuous strip. The separation sheet 3 is inserted between the walls 2, and these walls and the separation sheet 3 are connected along the longitudinal sides 4, for example, by welding with the formation of a tubular body with two compartments 5 and 5 '. According to the invention, each of said compartments 5, 5 is at least partially limited to the separator sheet 3.

As can be seen from FIG. 2, each wall 2 consists of an outer layer 6, which is a gas-tight material, preferably polyester or polyamide, and an inner layer 7, which is a material suitable for thermal soldering and for contacting with food products (in the preferred embodiment, this material is polyethylene or polypropylene). The outer and inner layers 6 and 7 have a uniform thickness and are tightly attached to each other, forming walls 2. In these walls, the inner surfaces 10 facing the chambers 5 and 5 'and the outer surfaces 11 facing outward with respect to the tubular body are preferably are smooth, i.e., having no protrusions, depressions or micro unevenness.

The separation sheet 3, also made of a material suitable for thermal soldering and for contacting with food, contains a continuous, essentially liquid-tight central layer 12. Protrusions 8 are projected from this layer into both compartments 5 and 5 '. They can penetrate to packaged products and, together with sections 13 of the surfaces of the central layer 12, to create a system of exhaust channels 9.

The projections 8 should be positioned so that the areas 13 of one surface of the central layer 12 are at least partially overlapped with the areas 13 of its other surface.

FIG. 3 shows a particularly preferred embodiment of the invention in which the positions of the protrusions 8 on the front and rear sides of the separation layer 3 exactly coincide with one another.

The protrusions 8 can have different configurations, and on the two surfaces of the separation layer 3 they can be arranged in a regular or irregular manner. As a result, one or several channels 9 systems are formed, which are continuous in the longitudinal direction relative to the tubular element and preferably (but not necessarily) communicate with each other. FIG. 4 shows examples of the configurations and locations of the protrusions 8, which have particular advantages in terms of quick and direct suction of air during the evacuation of the bag. FIG. 4a-4c, the protrusions 8 are formed by longitudinal bulges running in a continuous or intermittent manner substantially parallel to the longitudinal sides 4. In FIG. 46 and 4e show embodiments of the invention in which the protrusions 8 are in the shape of tubercles.

FIG. 5 and 6, other embodiments of the tubular element 1 are depicted. Essentially, they differ in the number of compartments 5, 5 'formed inside the tubular body, as well as the number of sheets or strips used to form the walls 2 and the release sheets 3.

FIG. 5 shows a tubular element 1, the wall 2 of which is optimally made from a single sheet. This sheet is superimposed on the separation sheet 3, bent together with it and, after aligning the longitudinal sides 4, thermal soldering is carried out on these sides, forming a tubular body.

Presented in FIG. 6, the tubular element 1 is made in a similar manner using four sheets or strips to form walls 2 and a corresponding number of sheets to form the separation sheets 3. The pre-fabricated elements 1 in which both the walls 2 and the separation sheets 3 are composed of several sheets or lanes, allow you to pack products,

- 2 006042 containing more than two separate parts, as well as vacuum packaging, in which the external forms and appearance can be adapted in accordance with the requirements imposed during storage, transportation and use.

In order to form the packages 14 for vacuum packaging of the products, the tubular element 1 is cut to the desired length and sealed in the transverse direction at the first end 15 (FIG. 7) with the preferred use of thermal soldering.

Next, with reference to FIG. 7, 8 and 9 describe the operation of the package 14, manufactured using the tubular element 1.

After the products 17 and / or information sheets are placed inside the compartments 5, 5 ', an exhaust nozzle 16 is inserted into the opening formed by the second end 15 ′ of the bag 14, so that the said compartments are completely and within reach of them . During the suction of air, the pressure inside the compartments 5, 5 'drops below the pressure from the outside of the bag 14. As a result, the walls 2 are bent towards the internal volume of the said compartments. In systems known so far, such deformation leads to partial or (in extreme cases) even complete overlapping of the exhaust ducts, which can be seen, for example, from FIG. 8a. The consequence of this is incomplete pumping package. In the package 14 according to the invention (see FIG. 3), both sides of the separation sheet 3 are under the influence of vacuum, and due to the shape and arrangement of the projections 8, a decrease in pressure on one side of the sheet 3 leads to such deformation of the sections 13, in which the channels 9 on the other side as can be seen in FIG. 8b, even more are revealed. The same effect occurs when the pressure on the other side of the sheet decreases. After pumping out the package 14, it is sealed, and preferably by thermal soldering along the second end 15 '.

FIG. 9 shows the situation in the package 14 according to the invention pumped out and sealed in this way, when only the first compartment 5 is used for storing products 17 (see also Fig. 3). Due to the easy and direct pumping of the second compartment 5 ', the pressure in it tends to drop even lower than the pressure in the first compartment 5. This leads to the effect of secondary evacuation of air residues from the compartment 5 due to diffusion (shown as dashed arrows in FIG. 9) through the separator sheet 3

The tubular element 1 and the package 14 according to the invention have many advantages.

In package 14, you can store several different products 17, without fear of the transfer of substances from one product to another. The outer walls are smooth and have a uniform thickness, i.e. for the specific material used, they have maximum strength. The formation of exhaust channels is functionally separated from the function of sealing and protection from the external environment. As a result, both the materials and the shape of the walls 2 and the release sheet 3 can be optimally selected. The adhesion of the walls of the exhaust channels 9 during the pumping out of the package 14 is prevented by pneumatic stabilization of the sections 13 of the channels 9. If some compartments 5, 5 'adjacent to the separator sheet 3 are not used to place products 17 in them, empty compartments or empty compartments form secondary evacuation chambers during the storage period of the vacuum package.

Of course, in order to satisfy specific and specific requirements, a person skilled in the art can make further modifications and changes with respect to the tubular element 1 according to the invention. However, all such modifications are within the scope of the invention as defined by the appended claims.

Claims (14)

CLAIM 1. A tubular element (1) for forming packages (14) intended for vacuum packaging of products (17), in particular perishable products, containing one or more walls (2) that are impermeable to gases, and at least one separating sheet ( 3) essentially impermeable to liquids and installed between the parts of the bent wall (2) or walls (2), with a single or each wall and a dividing sheet (3) connected along the longitudinal sides (4) to form a tubular body with two or several offices mi (5, 5 '), in which each compartment (5, 5') is at least partially limited by a separating sheet (3) containing a continuous liquid-tight central layer (12), from which into both adjacent compartments (5 , 5 ') protrusions (8) are provided, which together with the sections (13) of the surfaces of the central layer (12) create a system of exhaust channels (9). 2. The tubular element (1) according to claim 1, characterized in that a single or each wall (2) is formed by an outer layer (6), facing outwards relative to the tubular body and made of a material that is impermeable to gases, as well as internal a layer (7) facing the inner volume of the tubular body and made of a material suitable for thermal soldering, while the separating sheet (3) in the tubular element is made of a material suitable for thermal soldering. 3. The tubular element (1) according to claim 2, characterized in that the material of the inner layer (7) and material - 3 006042 separation layer (3) suitable for contact with food. 4. The tubular element (1) according to claim 2 or 3, characterized in that in it the outer and inner layers (6, 7) of the single or each wall (2) have uniform thicknesses and are tightly attached to each other along their surfaces. 5. The tubular element (1) according to any one of the preceding paragraphs, characterized in that a single or each wall (2) has essentially smooth inner and outer surfaces (10, 11). 6. The tubular element (1) according to any one of claims 1 to 5, characterized in that the protrusions (8) are arranged so that each section (13) of one surface of the central layer (12) at least partially overlaps one section (13) its other surface. 7. The tubular element (1) according to any one of the preceding paragraphs, characterized in that the outer layer (6) of a single or each wall (2) is made of polyester or polyamide, the inner layer (7) of a single or each wall (2) is made of polyethylene or polypropylene, and the separation sheet (3) is made of the same material as the inner layer (7). 8. The tubular element (1) according to any one of the preceding paragraphs, characterized in that the positions of the projections (8) on the front side of the separating sheet (3) correspond exactly to the positions of the projections (8) on its rear side. 9. The tubular element (1) according to any one of the preceding paragraphs, characterized in that the protrusions (8) are located on two surfaces of the separating sheet (3) in such a way as to form one or more systems of channels (9), which are continuous in the longitudinal direction along relative to the tubular element. 10. The tubular element (1) according to any one of the preceding paragraphs, characterized in that the protrusions (8) are formed by elongated bulges that extend in a continuous or intermittent manner substantially parallel to the longitudinal sides (4). 11. The tubular element (1) according to any one of the preceding paragraphs, characterized in that the protrusions (8) have the shape of tubercles. 12. Package (14) for vacuum packaging products (17), manufactured using a tubular element (1) according to any of the preceding paragraphs and sealed in the transverse direction along the first end (15). 13. Package (14) according to claim 12, characterized in that it is packed in the transverse direction by thermal soldering. 14. Package (14) according to claim 12 or 13, characterized in that it contains two walls (2) and a dividing sheet (3) installed between the walls (2), wherein the walls (2) and the dividing sheet (3) are connected along the longitudinal sides (4) to form a tubular body with two compartments (5, 5 ') in which the walls (2) contain an outer layer (6) impermeable to gases, and an inner layer (7) suitable for thermal soldering, the outer and inner layers (6, 7) are connected to each other along their surfaces, the continuous liquid-tight central layer (12) will separate The solid sheet (3) is not impermeable to gases, and the product-free compartment (5, 5 ') is configured to form a secondary pumping chamber for pumping out air residues in another compartment (5', 5) due to diffusion through a separating sheet (3 ).