Plastic tube for producing packaging containers having integrated ventilation

Abstract

The invention relates to a plastic tube (10) for producing packaging containers (12), in particular form-fill-seal bags, comprising: i) a shaped flat film (14), wherein the lateral edges of the flat film (14) which extend in the longitudinal direction (L) are arranged so as to overlap and are integrally bonded to one another along a first longitudinal seam (16), and ii) an infeed strip (18) which is located on the inner face of the plastic tube (10) and runs in the longitudinal direction (L), wherein: the infeed strip (18) is integrally bonded to the flat film (14) via a second longitudinal seam (20) and a third longitudinal seam (22) so that a ventilation channel (24) is formed which is spaced from the first first longitudinal seam (16) along the circumference of the plastic tube (10); the plastic tube (10) comprises multiple filling areas (26) which are located one behind the other in the longitudinal direction (L) and which are provided so that one packaging container (12) can be produced from each filling area (26); in relation to a filling area (26): x) the infeed strip (18) has one or more fluid-permeable first ventilation openings (28), and y) the flat film (14) has multiple fluid-permeable second ventilation openings (30) having a predetermined size; and the first ventilation openings (28) and the second ventilation openings (30) are each located in predetermined portions of the filling area.

Description

[0001] Plastic hose for the production of packaging containers with integrated ventilation

[0002] Description

[0003] The invention relates to a plastic tube for producing packaging containers, in particular FFS bags, and a corresponding filled packaging container. Also disclosed is a method for producing a filled packaging container according to the invention from a plastic tube according to the invention.

[0004] Plastics are now widely used in the packaging industry due to their diverse and often precisely adjustable properties. Plastic tubing for the manufacture of packaging containers is particularly distinguished by its cost-effective production, low weight, stability, tear resistance, and the ability to be fluid-tight. A product contained in a packaging container made of plastic tubing is thus optimally protected from moisture and the penetration of solids from the outside.

[0005] However, the fluid-tightness of plastic hoses regularly leads to problems with packaging containers made from plastic hoses. When filling a packaging container with a filling material, especially when filling it with bulk materials such as fertilizers, granules, foodstuffs, or building materials, unwanted air pockets often occur in the sealed packaging container. When the filled packaging containers are stacked, for example, on pallets, such air pockets greatly increase the risk of the plastic hose forming the packaging container bursting or tearing. Therefore, the packaging industry has developed various concepts for venting packaging containers made from plastic hoses. These concepts are intended to enable venting while preventing the contents from escaping.

[0006] For example, plastic packaging is known in the prior art that allows for venting via a vent channel. Venting is achieved here via the overlapping area that frequently arises during the production of plastic tubes, which is usually secured with a longitudinal seam to form plastic tubes from plastic films. The overlapping area can be used to create a vent channel, i.e., a two-layer layer that allows for venting of the packaging container in two stages, for example, through vent openings. A venting solution designed in this way offers the particular advantage that the overlapping area is usually located on the back of the packaging container.In this respect, a printed image on the front of the packaging container, which in practice is usually printed for labelling or advertising purposes, is not visually impaired by the longitudinal seam or the ventilation channel.

[0007] However, when venting via the back of packaging containers, it is often perceived as a disadvantage that additional work steps are usually required to adequately vent the packaged goods. Filled packaging containers are regularly placed on their back after filling for further transport or storage, so that a venting channel located there is compressed by the weight of the packaged goods. Ventilation is usually not possible or only inadequately possible in this way. It is therefore usually necessary to first place the packaging containers on the front, vent them manually, e.g., using pressure, and then turn the packaging containers over again after venting. This labor- and time-intensive procedure is often perceived as a disadvantage in practice.

[0008] As an alternative, concepts for venting packaging containers via the seams have been proposed, particularly via seam interruptions in the transverse seam. Venting via the transverse seam, i.e., one or both of the seams applied transversely to the longitudinal direction of the plastic tube during the manufacture of packaging containers from plastic tubes, has the advantage, particularly in combination with a venting area arranged on the top side via an inlet strip, of enabling effective venting without the need for the aforementioned turning of the packaging containers. Corresponding packaging containers are disclosed, for example, in EP 3052396 A1.

[0009] However, when venting via the transverse seam, it is sometimes considered disadvantageous that pressure equalization within the packaging container often leads to the contents or individual particles of the contents, particularly dust, escaping from the seam interruptions. In practice, this dusting of contents often leads to external contamination of the packaging containers and a work environment polluted with fine dust.

[0010] The primary object of the present invention was to eliminate or at least reduce the disadvantages of the prior art.

[0011] In particular, it was the object of the present invention to provide a plastic hose for producing packaging containers with a venting channel which should enable particularly efficient venting of the packaging container.

[0012] It was also an object of the present invention to provide a filled packaging container that would enable particularly efficient venting of the contents arranged inside, particularly when the packaging containers are stacked. It was also an object of the present invention to prevent, as far as possible, the escape of contents arranged inside the specified packaging container to the outside. A desirable requirement here was that even the escape of very small particles of the contents, in particular dust, from the packaging container should be prevented.

[0013] Furthermore, it was an object of the present invention that the plastic tubes to be specified allow the production of packaging containers which can be printed particularly efficiently, in particular without a front-side printed image being disturbed by a closing longitudinal seam.

[0014] Furthermore, it was an object of the present invention to provide a corresponding method for producing a packaging container to be specified from a plastic tube to be specified.

[0015] The inventors have now found that the above objects can be achieved if, in a flat film formed into a plastic tube and connected with a longitudinal seam, which comprises a plurality of successive filling regions, a venting channel is provided which is obtained by connecting an inlet strip to the flat film and is arranged opposite the longitudinal seam. The venting channel comprises first vent openings at a predetermined position in the inlet strip and second vent openings with a predefined shape at a predetermined position in the flat film for venting, as defined in the claims. This advantageously enables venting of a packaging container produced from the plastic tube with greatly reduced escape of filling material. At the same time, homogeneous printing of the plastic tube with as little disruption to the print image as possible is advantageously possible.

[0016] The above-mentioned objects are thus achieved by the subject matter of the invention as defined in the claims. Preferred embodiments of the invention emerge from the subclaims and the following statements. Those embodiments which are referred to as preferred below are combined in particularly preferred embodiments with features of other embodiments referred to as preferred. Combinations of two or more of the embodiments referred to as particularly preferred below are therefore very particularly preferred. Likewise preferred are embodiments in which a feature of an embodiment referred to as preferred to any extent is combined with one or more further features of other embodiments which are referred to as preferred to any extent.Features of preferred filled packaging containers and processes result from the features of preferred plastic tubes.

[0017] The invention relates to a plastic tube for producing packaging containers, in particular FFS bags, comprising: i) a shaped flat film, wherein the longitudinally extending side edges of the flat film are arranged to form the plastic tube in an overlapping manner and are integrally connected to one another along a first longitudinal seam, and ii) an inlet strip arranged on the inside of the plastic tube and extending in the longitudinal direction, wherein the inlet strip is integrally connected to the flat film by a second longitudinal seam and a third longitudinal seam, so that the flat film and the inlet strip form a venting channel, wherein the venting channel is spaced apart from the first longitudinal seam along the circumference of the plastic tube, wherein the plastic tube comprises a plurality of filling regions arranged one behind the other along the longitudinal direction, wherein the filling regions are providedthat a packaging container can be produced from each filling area, wherein, with respect to each filling area: x) the inlet strip comprises one or more fluid-permeable first vent openings through which a gas from the interior of the plastic tube can enter the vent channel, and y) the flat film comprises a plurality of fluid-permeable second vent openings through which a gas from the interior of the vent channel can escape, wherein the one or more first vent openings are arranged in the central section area between 0.2*LF and 0.8*LF with respect to the longitudinal direction, wherein the second vent openings are arranged in the lower section area from 0.02*LF to 0.2*LF and / or in the upper section area from 0.8*LF to 0.98*LF with respect to the longitudinal direction, wherein LF is the length of the filling area along the longitudinal direction,wherein the second vent openings have a quotient di / dB in the range of 1 to 5, where di is the maximum diameter of the second vent openings and dß is the diameter in the direction orthogonal to the maximum diameter, where di is 150 pm or less.

[0018] In accordance with expert understanding, the term "plastic hose" refers to a flexible, elongated hollow body with, for example, a round or oval cross-section. The plastic hose is open at its ends so that a filling material can be poured into it. The longitudinal direction of the plastic hose according to the invention is defined such that it runs from one of the ends of the plastic hose to be sealed to the other end to be sealed.

[0019] Along the longitudinal direction, the plastic hose according to the invention comprises a plurality of filling zones. Each individual filling zone can be filled, for example, using an FFS process, and then sealed to form a filled packaging container, so that any filling material arranged inside the filling zone cannot escape from the sealed packaging container. For industrial applications, a plastic hose according to the invention is preferred, wherein the plastic hose is provided on a roll. This ensures particularly space-efficient storage of the plastic hose and easy handling of the plastic hose during use. In most cases, the plastic hose according to the invention will have a predefined number of filling zones, from each of which a packaging container can be obtained.For example, a plastic hose according to the invention is conceivable, wherein the plastic hose comprises 150 or more, preferably 300 or more, particularly preferably 600 or more, filling regions arranged one behind the other along the longitudinal direction. The number of filling regions multiplied by their length yields the total length of the plastic hose. An example is a plastic hose according to the invention, wherein the plastic hose has a length of 350 m or more, preferably 750 m or more.

[0020] In an industrial context, the packaging containers obtained from plastic tubes according to the invention are usually provided with a marking, for example, a marking of the manufacturing company or the contents contained therein. The marking of the plastic tube according to the invention can also serve advertising purposes. Accordingly, a plastic tube according to the invention is preferred, wherein the plastic tube is a printed plastic tube, with the printed image preferably being repeated in each filling area.

[0021] The abbreviation "FFS" stands for "Form / Fill / Seal" in accordance with the expert understanding and refers to a process in which the production, filling, and sealing of packaging containers is made possible in a single technical system. An FFS bag is accordingly a packaging container produced using an FFS process. In the vast majority of cases, the plastic hose according to the invention is intended for the production of FFS bags, which are obtained in an FFS process from the filling areas of the plastic hose. A plastic hose according to the invention is therefore preferred, wherein the filling areas are provided so that a packaging container can be produced from each filling area in an FFS process. The plastic hose according to the invention will - in keeping with its name - consist largely of plastic in most applications.The formed flat film, which forms the outer wall and, to a large extent, the inner wall of the plastic hose according to the invention, is accordingly made predominantly, and in most cases essentially entirely, of plastic. Plastics offer particularly cost-effective solutions for a wide variety of requirement profiles. In this case, the use of plastics can produce a particularly robust and tear-resistant flat film which is fluid-tight and thus optimally encloses a filling material inside the plastic hose. The fluid-tightness also prevents the penetration of moisture, so that a filling material arranged inside, for example a building material such as concrete, is reliably protected. For most applications and with a view to sustainable use, it is preferable to make the flat film from a recycled plastic.At least theoretically, it would also be conceivable for the flat film to additionally comprise further materials, such as nonwovens for filtering escaping gases or for cushioning a filling material arranged in the plastic tube. For most cases, however, a plastic tube according to the invention is preferred, wherein the flat film comprises a plastic selected from the group consisting of polyamides and polyolefins, preferably selected from the group consisting of polyethylene, polypropylene and polyhexamethylene adipamide. Additionally or alternatively, a plastic tube according to the invention is preferred, wherein the flat film consists of a plastic to a mass fraction of 90% or more, preferably 95% or more, particularly preferably 99% or more, very particularly preferably substantially 100%, based on the mass of the flat film.

[0022] In some applications, it can be advantageous to construct the flat film from different plastics, particularly plastics in a multi-layer composite. A plastic tube with a multi-layer flat film can be advantageous, for example, when particularly stringent sealing requirements are met in combination with a high dead weight of the contents. A multi-layer film can also be advantageous when strict requirements are placed on the cleanliness of the packaging container or when externally prescribed hygiene regulations apply, such as those found in clean rooms. In this case, for example, the outer layer of the flat film can be peeled off, so that the dirt adhering to the outer wall of the flat film can be removed and a clean outer shell can be created.A plastic hose according to the invention is preferred, wherein the flat film is a multi-layer flat film, wherein the plastic hose is preferably designed so that the one or more outer layers of the multi-layer flat film can be separated from the one or more inner layers of the multi-layer flat film at a desired separation surface, preferably by manually peeling off the one or more outer layers.

[0023] The flat film in this case is characterized by its low thickness, meaning that its expansion in the radial direction of the cylindrical hollow body is limited. The specific dimensions of the flat film will be selected depending on the requirements to be met, for example, high tear resistance. However, the inventors have identified parameters for the thickness that allow a high filling volume with filling material on the one hand and a high tear resistance of the flat film on the other. Preferred is a plastic tube according to the invention, wherein the flat film has an average thickness in the range of 40 to 200 μm, preferably in the range of 80 to 180 μm, particularly preferably in the range of 100 to 150 μm.

[0024] The plastic hose according to the invention is formed by overlapping the flat film along the side edges, i.e., along the longitudinal direction. The overlapping side edges are secured with a first longitudinal seam, which also runs along the longitudinal direction. In most cases, a plastic hose according to the invention is relevant, wherein the first longitudinal seam is an adhesive seam or a welded seam, preferably an adhesive seam.

[0025] The inventors have found that in most cases it is advantageous to place the longitudinal seam on the plastic tube according to the invention such that its position in the packaging container obtained from the plastic tube lies on the back of the packaging container obtained therefrom. The person skilled in the art understands that the front or the back of the resulting packaging container is essentially determined by the subsequent handling of the packaging container to be obtained, for example by one of the sides being designated as the front by means of a label or advertising print. Printing of the plastic tube on the front of the resulting packaging container can advantageously be carried out without interruptions within the scope of the present invention if the first longitudinal seam is arranged on the back.

[0026] The inventors consider it expedient if the first longitudinal seam is a continuous seam. Due to the rear position of the first longitudinal seam, venting via this seam is explicitly not desired. In practice, venting via the first longitudinal seam would result in the packaging containers obtained from the plastic tube having to be turned over after filling for venting. Within the scope of the present invention, venting of the filled packaging container obtained from the plastic tube should therefore not occur via the first longitudinal seam, so that no venting area needs to be provided in this part. A plastic tube according to the invention is therefore preferred, wherein the side edges of the flat film are connected to one another with exactly one longitudinal seam to form the plastic tube.Also preferred is a plastic hose according to the invention, wherein no venting region is formed in the region of the first longitudinal seam between the side edges of the flat film. Additionally or alternatively, a plastic hose according to the invention is also preferred, wherein the first longitudinal seam forms a continuous, fluid-tight connection between the side edges of the flat film, at least over the length of the filling region, preferably over the entire length of the plastic hose.

[0027] In the context of the present invention, the venting of a packaging container obtained from the plastic tube according to the invention takes place via a venting channel. The venting channel is formed by connecting the flat film to an inlet strip running inside the plastic tube. The side edges of the inlet strip are each connected to the flat film with a second longitudinal seam running along the longitudinal direction and a third longitudinal seam running along the longitudinal direction.

[0028] The difference between a film and a strip is fundamentally clear to those skilled in the art. Accordingly, those skilled in the art understand that the inlet strip for forming the venting channel along the circumference of the plastic tube will have a smaller extension, i.e., a smaller width, than the formed flat film. As previously explained, venting is desired via the front of the packaging container to be produced from the plastic tube. Therefore, in most applications, the width of the inlet strip will not exceed 25% of the width of the flat film.

[0029] In principle, the inlet strip is not limited in terms of its composition. However, the inventors propose that the inlet strip also be made of a plastic in order to obtain a particularly tear-resistant, robust, and fluid-tight venting channel. For most applications and with a view to sustainable use, it is also preferable to make the inlet strip from a recycled plastic. A plastic hose according to the invention is preferred, wherein the inlet strip comprises a plastic selected from the group consisting of polyesters, polyamides, and polyolefins, preferably selected from the group consisting of polyethylene terephthalate, polyethylene, polypropylene, and polyhexamethylene adipamide.Additionally or alternatively, a plastic hose according to the invention is also preferred, wherein the inlet strip consists of a plastic to a mass fraction of 90% or more, preferably 95% or more, particularly preferably 99% or more, very particularly preferably substantially 100%, based on the mass of the inlet strip. At least in principle, applications are conceivable in which the inlet strip comprises other materials, for example to increase gas permeability, such as nonwovens. A plastic hose according to the invention is preferred, wherein the inlet strip has an average thickness in the range from 40 to 200 pm, preferably in the range from 80 to 180 pm, particularly preferably in the range from 100 to 150 pm.

[0030] With a view to cost-efficient production of the plastic hose according to the invention, the inventors consider it preferable to form the inlet strip from the same material as the flat film. This advantageously also reduces the equipment required for the production of corresponding plastic hoses. In addition, the same joining technology can be used for the second longitudinal seam and the third longitudinal seam as for the first longitudinal seam, thereby minimizing stresses in the joint that could arise, for example, from different thermal expansion coefficients. For a first longitudinal seam designed as an adhesive seam, the same adhesive could be used, and for a first longitudinal seam designed as a welded seam, the same welding parameters, in particular the same welding temperature, could be used.A plastic hose according to the invention is therefore preferred, wherein the inlet strip is made of the same material as the flat film.

[0031] The inventors consider it expedient if the second longitudinal seam and the third longitudinal seam are continuous seams. This ensures that the packaging container obtained from the plastic tube according to the invention is vented not via the seams themselves, but exclusively via the first vent openings provided for this purpose. This advantageously reduces the undesired escape of dust from a filling material arranged inside the plastic tube to the outside. Therefore, a plastic tube according to the invention is preferred, wherein the second longitudinal seam and the third longitudinal seam form a continuous, fluid-tight connection between the inlet strip and the flat film at least over the length of the filling area, preferably over the entire length of the plastic tube.Additionally or alternatively, a plastic hose according to the invention is also preferred, wherein the second longitudinal seam and the third longitudinal seam are adhesive seams or welded seams, preferably adhesive seams. With a view to the efficiency of the method, the inventors consider it preferable to supply the inlet strip as a continuous strip. In this respect, the inlet strip can also be provided on a roll. In a preferred embodiment, the inlet strip - and thus also the venting channel - is arranged over its entire length inside the plastic hose. Accordingly, a plastic hose according to the invention is preferred, wherein the venting channel extends at least over the length of the filling regions, preferably over the entire length of the plastic hose, on the inside of the plastic hose.Additionally or alternatively, a plastic hose according to the invention is also preferred, wherein the inlet strip is arranged on the inside of the plastic hose at least over the length of the filling areas, preferably over the entire length of the plastic hose.

[0032] According to the invention, the venting channel is arranged at a distance from the first longitudinal seam along the circumference of the plastic tube. This is advantageous because the venting channel will thus in most cases be arranged on the front side of a packaging container obtained from the plastic tube. Printing on the front side is only possible without interruption if the venting channel is arranged inside the plastic tube. In other words, this is a plastic tube in which the first longitudinal seam and the inlet strip do not overlap. This is advantageous from a technical point of view because multi-layer seams can lead to an undesirably increased thickness of the plastic tube at the relevant position. In addition, a multi-layer seam, for example a multi-layer weld seam, can be technically difficult to implement.The inventors further consider it preferable if the spacing is such that the venting channel is not located in the side fold of the packaging container obtained from the plastic tube according to the invention. In the majority of applications, it is preferable to provide the venting channel on the front side of the packaging container obtained from the plastic tube according to the invention. In other words, the venting channel will usually be positioned opposite the first longitudinal seam arranged on the rear side of the packaging container. This advantageously enables venting of a filling material arranged in such a packaging container even when it is lying on its rear side. In this respect, such a packaging container advantageously does not need to be turned over for sufficient venting.A plastic hose according to the invention is therefore preferred, wherein the venting channel is spaced along the circumference of the plastic hose from the first longitudinal seam by 0.3*U or more, preferably by 0.45*U or more, particularly preferably by 0.6*U or more, where U is the mean circumference of the plastic hose, wherein the venting channel is very particularly preferably arranged in the quadrant opposite the first longitudinal seam with respect to the circumference of the plastic hose, wherein the venting channel is very particularly preferably arranged substantially on the opposite side of the first longitudinal seam with respect to the circumference of the plastic hose.

[0033] In addition to the second longitudinal seam and the third longitudinal seam, the inlet strip can be integrally bonded to the flat film with further seams, in particular longitudinal or transverse seams. This advantageously allows segmentation of the venting channel to be achieved, which can, in particular, prevent the escape of dust during venting of a packaging container obtained from the plastic tube according to the invention. This is also achieved in particular by restricting the direct venting of a resulting packaging container by such a labyrinth system in the venting channel as an obstacle, so that controlled venting occurs via the venting channel.Therefore, a plastic hose according to the invention is preferred, wherein the ventilation channel is divided into two or more sub-segments connected to one another in a fluid-conducting manner by one or more further longitudinal seams and / or transverse seams, preferably adhesive seams, which firmly connect the inlet strip to the flat film.

[0034] According to the invention, the plastic tube comprises, in each filling area, first vent openings in the central section of the inlet strip and second vent openings in the lower and / or upper section of the flat film. In other words, a packaging container obtained from the plastic tube comprises first vent openings in the ventilation channel centrally in the inlet strip and second vent openings at the top and / or bottom of the flat film. The inventors consider this arrangement of the first and second vent openings to be particularly preferred, since in a packaging container obtained from the plastic tube according to the invention, escape of contents is particularly efficiently prevented. The escape of contents from a filled packaging container is undesirable in the vast majority of cases. In particular, the escape of small particles of the contents, for example dust, is undesirable.This can lead to difficulties in handling or increased requirements in handling such filled packaging containers, particularly in the case of building materials such as concrete, but also in the case of other filling materials, for example filling materials that contain substances that are harmful to health.

[0035] According to the inventors, it is the specific combination of the position of the venting openings with their specific design that leads to an advantageous venting effect, which is particularly superior to other venting solutions that place venting via the seams in terms of venting performance and retention of the filling material.

[0036] An example is a plastic hose according to the invention, wherein the inlet strip comprises two or more, preferably three or more, particularly preferably five or more, very particularly preferably seven or more, especially preferably eleven or more, first vent openings in each filling area. Additionally or alternatively, an example is also a plastic hose according to the invention, wherein the flat film comprises 20 or more, preferably 30 or more, particularly preferably 50 or more, very particularly preferably 70 or more, second vent openings in each filling area.

[0037] The inventors have found that the escape of filling material can be particularly effectively prevented if the first venting openings and the second venting openings are each provided in a predefined area, ie as a local collection of venting openings, for example in a section limited in area. Therefore, a plastic hose according to the invention is preferred, wherein all first venting openings of the filling area are arranged in a venting section, preferably in a regular arrangement, wherein the venting section has an area in the range of 0.001*A z up to 0.5*A z , preferably in the range of 0.01*A z up to 0.1*A z , particularly preferably in the range of 0.02*A z up to 0.06*A z , where A zthe surface of the inlet strip facing into the interior of the venting channel. Additionally or alternatively, a plastic hose according to the invention is also preferred, wherein all second venting openings of the filling region are arranged in one or two, preferably two, venting sections, preferably in a regular arrangement with respect to each venting section, wherein the venting section(s) each have an area in the range from 0.001*AF to 0.5*AF, preferably in the range from 0.01*AF to 0.1*AF, particularly preferably in the range from 0.02*AF to 0.06*AF, wherein AF is the surface of the flat film facing into the interior of the venting channel.Particularly preferred is a plastic hose according to the invention, wherein the second vent openings are arranged in the lower section region and in the upper section region, wherein the second vent openings are preferably distributed substantially uniformly over the lower and upper section regions.

[0038] The inventors have recognized that the specific positioning of the first vent openings and the second vent openings in the filling area has a significant influence on the successful venting of the filling area. Within the scope of the present invention, the absolute position of the vent openings is specified by the position of the vent openings relative to the length of the filling area along the longitudinal direction. In relation to the subsequently filled packaging container, this means that the central section area designates the central part of the packaging container, while the upper and lower section areas form the side edges of the packaging container.

[0039] According to the inventors, the unwanted escape of contents can be minimized if the distance between the first venting openings and the second venting openings is maximized, while at the same time positioning the first venting openings as centrally as possible. In concrete terms, this means that—for the preferred case of two venting sections—the second venting openings are positioned along the longitudinal direction at the end sections of the venting channel, and the first venting openings are positioned in its center. However, according to the inventors, a minimum distance from the edges of the filling area should preferably be maintained to prevent a filled packaging container obtained from the plastic tube from being vented at the seams separating the filling areas. This advantageously prevents dust from forming on the contents.A plastic hose according to the invention is therefore preferred, wherein the one or more first venting openings, in particular the ventilation section, are arranged in the central section region between 0.25* LF and 0.75* LF, preferably between 0.3* LF and 0.7* LF, particularly preferably between 0.35* LF and 0.65* LF, very particularly preferably between 0.4* LF and 0.6* LF, based on the longitudinal direction. Additionally or alternatively, a plastic hose according to the invention is also preferred, wherein the one or more first venting openings, in particular the ventilation section, are arranged in the central region between 0.25*B and 0.75*B, preferably between 0.3*B and 0.7*B, particularly preferably between 0.35*B and 0.65*B, based on the transverse direction of the inlet strip orthogonal to the longitudinal direction, where B is the width of the inlet strip in the transverse direction.

[0040] In principle, a plastic hose according to the invention is also preferred, wherein the one or more first venting openings are arranged predominantly, preferably very predominantly, particularly preferably to 70% or more, very particularly preferably to 90% or more, particularly preferably substantially completely, in the central section region, based on the number of first venting openings.

[0041] The arrangement of the second venting openings required according to the invention does not in principle rule out the provision of further venting openings outside these section regions, which fall within the definition of the second venting openings, for example because needling extends over the edge regions of the filling regions into the next filling region. However, it is preferred that the second venting openings are arranged predominantly, preferably essentially completely, in the respective section regions. Likewise preferred is a plastic hose according to the invention, wherein the second venting openings are arranged, based on the longitudinal direction, in the lower section region from 0.05*LF to 0.15*LF, and / or in the upper section region from 0.85*LF to 0.95*LF, where LF is the length of the filling region along the longitudinal direction.

[0042] Particularly preferred is, in principle, a plastic hose according to the invention, wherein the second venting openings are arranged predominantly, preferably very predominantly, particularly preferably to 70% or more, very particularly preferably to 90% or more, particularly preferably substantially completely, in the lower section region and / or in the upper section region, based on the number of second venting openings.

[0043] In principle, the inventors consider it preferable to adapt the geometric shape and the absolute size of the first venting openings to the contents to be packaged. The inventors have found that, for effective venting, ventilation slots are particularly suitable as first venting openings. Therefore, a plastic tube according to the invention is preferred, wherein the one or more first venting openings are selected from the group consisting of ventilation holes and ventilation slots, preferably ventilation slots, wherein the ventilation slots enclose an angle with the longitudinal direction in the range of 80 to 90°, preferably in the range of 85 to 90°, particularly preferably in the range of 88 to 90°, wherein the ventilation slots particularly preferably run substantially parallel to the longitudinal direction.

[0044] The inventors have identified specific parameters for the geometric dimensions of the first vent openings, with which particularly good venting performance could be achieved with minimal escape of filling material into the vent channel, with elongated openings in the form of slots being particularly preferred. A plastic hose according to the invention is preferred, wherein the one or more first vent openings have a quotient qi_ / qB in the range from 1 to 50, preferably in the range from 2 to 30, particularly preferably in the range from 3 to 10, where qL is the maximum diameter of the first vent openings and qB is the diameter in the direction orthogonal to the maximum diameter.

[0045] As explained above, in most applications it is preferred if a filling material arranged in the plastic hose cannot escape too easily through the vent openings to the outside. The inventors have found that it is advantageous to design the second vent openings to be essentially circular, preferably point-shaped. A plastic hose according to the invention is therefore preferred, wherein the second vent openings have a quotient di / dB in the range from 1 to 4.5, preferably in the range from 1 to 3, particularly preferably in the range from 1 to 1.5. Additionally or alternatively, a plastic hose according to the invention is also preferred, wherein the second vent openings have a cross-sectional shape selected from the group consisting of circles and polygons, preferably circles and rectangles.

[0046] With a view to minimizing the unwanted escape of contents from a packaging container producible from the plastic tube according to the invention, the inventors consider it preferable to make the second venting openings as small as possible, which is advantageously possible in the plastic tube according to the invention due to the optimal positioning, without overly adversely affecting the venting performance. This additionally reduces the risk of fluids and / or solids entering the venting channel from the outside. Preference is therefore given to a plastic tube according to the invention, wherein d.i. is 125 μm or less, preferably 100 μm or less. Additionally or alternatively, preference is also given to a plastic tube according to the invention, wherein the second venting openings can be produced by needling the flat film.

[0047] The inventors propose that the venting performance can be further improved if spacers are provided inside the venting channel, which counteract complete compression of the venting channel. These can preferably be achieved by embossing the flat film or the inlet strip, by which they have channel-defining elevations. A plastic hose according to the invention is preferred for this purpose, wherein a plurality of embossed elevations are provided on the surface of the flat film and / or the inlet strip facing into the interior of the venting channel, wherein the embossed elevations preferably have a height in the range of 50 to 500 μm, preferably in the range of 100 to 400 μm, particularly preferably in the range of 200 to 350 μm.

[0048] In a synergistic manner, the embossed elevations can be formed together with the venting openings, so that they have an edge due to the manufacturing process, which acts as a local spacer. In this case, a plastic hose according to the invention is preferred, wherein the first venting openings and / or the second venting openings have a partially circumferential, preferably substantially completely circumferential, edge elevation on the surface of the flat film or of the feed strip facing into the interior of the venting channel, which edge elevation extends into the venting channel. A plastic hose according to the invention is particularly preferred, wherein the edge elevations have a height in the range from 50 to 500 pm, preferably in the range from 100 to 400 pm, particularly preferably in the range from 200 to 350 pm.

[0049] As explained above, both the geometric shape and the absolute number and position of the venting openings within the venting channel influence the venting of a packaging container obtained from the plastic tube according to the invention. A plastic tube according to the invention is preferred, wherein the combined venting capacity of a filling area through the first venting openings, the venting channel, and the second venting openings is in the range of 1 to 25 L / min, preferably in the range of 2 to 15 L / min, particularly preferably in the range of 3 to 6 L / min. The invention also relates to a filled packaging container, in particular an FFS bag, preferably producible from a plastic tube according to the invention, comprising:

[0050] I) a shaped flat film, wherein the side edges of the flat film are arranged overlapping and are connected to one another in a material-locking manner along a first longitudinal seam, wherein the flat film is closed by a material-locking connection on the top side of the packaging container along a first transverse seam and on the underside of the packaging container along a second transverse seam to form a container interior,

[0051] II) an inlet strip arranged on the inside of the packaging container and extending in the longitudinal direction, wherein the inlet strip is integrally connected to the flat film by a second longitudinal seam and a third longitudinal seam, so that the flat film and the inlet strip form a venting channel, wherein the venting channel is spaced apart from the first longitudinal seam along the circumference of the packaging container, wherein the venting channel is closed at the top of the packaging container by the first transverse seam and at the bottom of the packaging container by the second transverse seam, and

[0052] III) a packaging item arranged in the container interior, wherein, with respect to the packaging container: x) the inlet strip comprises one or more fluid-permeable first vent openings through which a gas from the container interior can enter the vent channel, and y) the flat film comprises a plurality of fluid-permeable second vent openings through which a gas from the interior of the vent channel can escape, wherein the one or more first vent openings are arranged in the central section region between 0.2*LF and 0.8*LF with respect to the longitudinal direction, wherein the second vent openings are arranged in the lower section region from 0.02*LF to 0.2*LF and / or in the upper section region from 0.8*LF to 0.98*LF with respect to the longitudinal direction, wherein LF is the length of the formed flat film along the longitudinal direction from the first transverse seam to the second transverse seam,wherein the second vent openings have a quotient di / dB in the range of 1 to 5, where di is the maximum diameter and dß is the diameter in the direction orthogonal to the maximum diameter, where di is 150 pm or less.

[0053] The filled packaging container according to the invention can be produced from a plastic tube according to the invention. Those skilled in the art will understand that the advantages of preferred embodiments of the plastic tube also apply to filled packaging containers.

[0054] The first transverse seam of the packaging container according to the invention is arranged on its top side, and the second transverse seam of the packaging container according to the invention is arranged on its bottom side. In most applications, this means that the first transverse seam and the second transverse seam seal the filled packaging container fluid-tight at the transverse seam. An example of a filled packaging container according to the invention is one in which the first transverse seam and / or the second transverse seam, preferably the first transverse seam and the second transverse seam, are adhesive seams or welded seams, preferably welded seams.

[0055] In the vast majority of cases, venting of the contents in the filled packaging container is desired exclusively via the venting channel. Therefore, it is expedient to form the first transverse seam and the second transverse seam as continuous seams, creating a fluid-tight connection. This advantageously prevents any contents and / or fluid from escaping through the transverse seam. Therefore, a filled packaging container according to the invention is preferred, wherein the first transverse seam and the second transverse seam form a continuous, fluid-tight connection of the flat film across the entire width of the plastic tube.

[0056] Also exemplary is a filled packaging container according to the invention, wherein the packaged goods are selected from the group consisting of particulate solids.

[0057] Also disclosed in connection with the invention is a method for producing a filled packaging container according to the invention from a plastic tube according to the invention, comprising the method steps: a) producing or providing the plastic tube on a filling system, b) moving a filling area into the filling position, wherein the plastic tube is closed in the filling position at the lower end of the filling area transversely to the longitudinal direction to form a receiving space and forming the first transverse seam at the lower end of the filling area, c) filling the receiving space with the packaged goods, d) producing the filled packaging container by forming the second transverse seam at the upper end of the filling area.

[0058] Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings.

[0059] Fig. 1 is a schematic representation of a plastic hose according to the invention in a preferred embodiment;

[0060] Fig. 2 is a schematic representation of an individual filling area of ​​the plastic hose according to the invention of Fig. 1;

[0061] Fig. 3 is a schematic representation of a filled packaging container according to the invention, obtained from the filling area shown in Fig. 2; and Fig. 4 is a schematic exploded view of the venting channel of the plastic hose according to the invention of Fig. 1.

[0062] Fig. 1 shows a plastic tube 10 according to the invention for producing packaging containers 12, in particular FFS bags.

[0063] The plastic hose 10 comprises a flat film 14 formed into a tube with overlapping side edges, which is made of polyethylene. The shape of the flat film 14 is held firmly in place by precisely one first longitudinal seam 16, designed as an adhesive seam, which fixes the overlapping side edges of the flat film 14 along the longitudinal direction L of the plastic hose 10. In the example shown in Fig. 1, the longitudinal direction L is indicated by a directional arrow.

[0064] The plastic hose 10 additionally comprises an inlet strip 18 arranged inside the flat film 14, which is made of the same material as the flat film 14. The inlet strip 18 has, based on the circumference of the plastic hose 10, approximately 1 / 8 of the width of the flat film 14 and is integrally connected to the flat film 14 along its side edges in the longitudinal direction L by a second longitudinal seam 20 and a third longitudinal seam 22. The second longitudinal seam 20 and the third longitudinal seam 22 are designed as adhesive seams. The second longitudinal seam 20 and the third longitudinal seam 22 each form a continuous, fluid-tight connection between the inlet strip 18 and the flat film 14 over the entire length of the plastic hose 10.

[0065] This forms a venting channel 24, which is arranged on the plastic hose 10 opposite the first longitudinal seam 16 and extends over the entire length of the plastic hose 10 on its inside. An exploded view of the venting channel is shown schematically in Fig. 4.

[0066] Along its longitudinal direction L, the plastic hose 10 comprises a plurality of identically designed filling areas 26 arranged one behind the other. The plastic hose 10 shown is printed, with the print image being repeated in each filling area 26. In the example shown in Fig. 1, only three filling areas 26 are shown for reasons of clarity. Fig. 2 shows a single filling area 26 of the plastic hose 10 shown in Fig. 1. Each filling area 26 has a plurality of fluid-permeable first vent openings 28 in the inlet strip 18, through which a gas from the interior of the plastic hose 10 can enter the vent channel 24. The schematic filling area 26 shown comprises a total of sixteen first vent openings 28, which are arranged in a regular arrangement centrally in the inlet strip 18. The first vent openings 28 are designed as ventilation slots that extend along the longitudinal direction L.The first vent openings 28 are located centrally in the central section of the filling area 26, namely at approximately 0.5* LF, where LF is the length of the filling area 26 along the longitudinal direction L.

[0067] In addition, the flat film 14 has, in each filling region 26 in the region of the venting channel 24, a plurality of fluid-permeable second vent openings 30a, 30b through which a gas can escape from the interior of the venting channel 24. The second vent openings 30a-b are designed as vent holes with a diameter of approximately 100 μm and are arranged in two venting sections in the lower and upper section regions of the filling region 26. In the schematic example shown, the venting sections each comprise, in a regular arrangement, thirty second vent openings 30a-b, which in the example shown were produced by needling the flat film 14.

[0068] In the example shown, the filling areas 26 are each provided so that a packaging container 12 can be produced from them using an FFS process. Such a filled packaging container 12, made from the plastic tube of Fig. 1 and correspondingly designed as an FFS bag, is shown in Fig. 3. To form a container interior, the flat film 14 is sealed by a material-to-material connection on the top side of the packaging container 12 along a first transverse seam 32 and on the bottom side of the packaging container 12 along a second transverse seam 34.

[0069] The first transverse seam 32 and the second transverse seam 34 are designed as continuous weld seams, forming a continuous, fluid-tight connection of the flat film 14 across the entire width of the plastic tube 10, and preventing venting via the transverse seams. This advantageously reliably prevents dust from escaping from the contents inside the packaging container 12.

[0070] Reference symbol

[0071] 10 plastic hoses

[0072] 12 Packaging container 14 Flat film

[0073] 16 first longitudinal seam

[0074] 18 inlet strips

[0075] 20 second longitudinal seam

[0076] 22 third longitudinal seam 24 ventilation channel

[0077] 26 Filling area

[0078] 28 first vents

[0079] 30a, 30b second vent openings

[0080] 32 first cross seam 34 second cross seam

[0081] L longitudinal direction

Claims

Claims 1. A plastic tube (10) for producing packaging containers (12), in particular FFS bags, comprising: i) a shaped flat film (14), wherein the side edges of the flat film (14) extending in the longitudinal direction (L) are arranged to overlap to form the plastic tube (10) and are integrally connected to one another along a first longitudinal seam (16), and ii) an inlet strip (18) arranged on the inside of the plastic tube (10) and extending in the longitudinal direction (L), wherein the inlet strip (18) is integrally connected to the flat film (14) by a second longitudinal seam (20) and a third longitudinal seam (22), so that the flat film (14) and the inlet strip (18) form a venting channel (24), wherein the venting channel (24) is spaced apart from the first longitudinal seam (16) along the circumference of the plastic tube (10). is,wherein the plastic tube (10) comprises a plurality of filling regions (26) arranged one behind the other along the longitudinal direction (L), wherein the filling regions (26) are provided so that a packaging container (12) can be produced from each filling region (26), wherein, with respect to a filling region (26): x) the inlet strip (18) comprises one or more fluid-permeable first venting openings (28) through which a gas from the interior of the plastic tube (10) can enter the venting channel (24), and y) the flat film (14) comprises a plurality of fluid-permeable second venting openings (30) through which a gas from the interior of the venting channel (24) can escape, wherein the one or more first venting openings (28) are, with respect to the longitudinal direction (L), in the central section region between 0.2*L, F and 0.8*L F are arranged, wherein the second vent openings (30) are arranged in the lower section range from 0.02*LF to 0.2*LF and / or in the upper section range from 0.8*LF to 0.98*LF with respect to the longitudinal direction (L), wherein LF is the length of the filling region (26) along the longitudinal direction (L), wherein the second vent openings (30) have a quotient di / dB in the range from 1 to 5, wherein di. is the maximum diameter of the second vent openings (30) and dß is the diameter in the direction orthogonal to the maximum diameter, wherein di. is 150 pm or less.

2. Plastic hose (10) according to claim 1, wherein the venting channel (24) extends at least over the length of the filling areas (26) on the inside of the plastic hose (10).

3. Plastic hose (10) according to one of claims 1 or 2, wherein the venting channel (24) is spaced along the circumference of the plastic hose (10) from the first longitudinal seam (16) by 0.3*U or more, where U is the mean circumference of the plastic hose (10), wherein the venting channel (24) is preferably arranged in the quadrant opposite the first longitudinal seam (16) with respect to the circumference of the plastic hose (10).

4. Plastic hose (10) according to one of claims 1 to 3, wherein the venting channel (24) is divided into two or more sub-segments connected to one another in a fluid-conducting manner by one or more further longitudinal seams and / or transverse seams.

5. Plastic hose (10) according to one of claims 1 to 4, wherein the one or more first vent openings (28) are selected from the Group consisting of ventilation slots, wherein the ventilation slots enclose an angle in the range of 80 to 90° with the longitudinal direction (L).

6. Plastic hose (10) according to one of claims 1 to 5, wherein the one or more first vent openings (28) have a quotient qi / qB in the range from 1 to 50, where qi is the maximum diameter of the first vent openings (28) and qe is the diameter in the direction orthogonal to the maximum diameter, and / or wherein the second vent openings (30) have a quotient di / dß in the range from 1 to 4.

5.

7. Plastic hose (10) according to one of claims 1 to 6, wherein all first vent openings (28) of the filling area (26) are arranged in a ventilation section, wherein the ventilation section has an area in the range of 0.001*A z up to 0.5*A z where A zthe surface of the inlet strip (18) facing into the interior of the venting channel (24), and / or wherein all second venting openings (30) of the filling area (26) are arranged in one or two venting sections, wherein the venting section(s) each have an area in the range from 0.001*AF to 0.5*AF, wherein AF is the surface of the flat film (14) facing into the interior of the venting channel (24).

8. Plastic hose (10) according to one of claims 1 to 7, wherein di. is 125 pm or less.

9. Filled packaging container (12), in particular FFS bag, preferably producible from a plastic tube (10) according to one of claims 1 to 8, comprising: I) a shaped flat film (14), wherein the side edges of the flat film (14) are arranged overlapping and are connected to one another along a first longitudinal seam (16), wherein the flat film (14) is glued to the top side of the container to form an interior space packaging container (12) along a first transverse seam (32) and on the underside of the packaging container (12) along a second transverse seam (34) by a material-to-material connection, II) an inlet strip (18) arranged on the inside of the packaging container (12) and extending in the longitudinal direction (L), wherein the inlet strip (18) is integrally connected to the flat film (14) by a second longitudinal seam (20) and a third longitudinal seam (22), so that the flat film (14) and the inlet strip (18) form a venting channel (24), wherein the venting channel (24) is spaced apart from the first longitudinal seam (16) along the circumference of the packaging container (12), wherein the venting channel (24) is closed at the top of the packaging container (12) by the first transverse seam (32) and at the bottom of the packaging container (12) by the second transverse seam (34), and III) a packaging material arranged in the container interior, wherein, with respect to the packaging container (12): x) the inlet strip (18) has one or more fluid-permeable first Vent openings (28) through which a gas from the Container interior can enter the venting channel (24), and y) the flat film (14) has a plurality of fluid-permeable second Ventilation openings (30) through which a gas can escape from the interior of the ventilation channel (24), wherein the one or more first ventilation openings (28) are arranged in the central section region between 0.2*LF and 0.8*LF with respect to the longitudinal direction (L), wherein the second ventilation openings (30) are arranged in the lower section region of 0.02*LF with respect to the longitudinal direction (L) F up to 0.2*L F and / or in upper section range from 0.8*LF to 0.98*LF, where LF is the length of the shaped flat film (14) along the longitudinal direction (L) from the first transverse seam (32) to the second transverse seam (34), the second vent openings (30) having a quotient di / dB in the range from 1 to 5, where di_ is the maximum diameter and dß is the diameter in the direction orthogonal to the maximum diameter, where di is 150 pm or less.

10. Filled packaging container (12) according to claim 9, wherein the first transverse seam (32) and the second transverse seam (34) extend over the entire width of the Plastic hose (10) form a continuous, fluid-tight connection of the flat film (14).

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