METHOD FOR PRODUCING FLEXIBLE TUBE BODIES FOR PACKAGING TUBES, FLEXIBLE TUBE BODY FOR PACKAGING TUBES, AND DEVICE FOR PRODUCING FLEXIBLE TUBE BODIES FOR PACKAGING TUBES

Abstract

The invention relates to a method for producing flexible tube bodies (18) for packaging tubes from a film substrate (1) which has a print, preferably on an outer side (2), and which has or consists of at least one weldable plastic layer and which comprises a first longitudinal edge side (8), which extends in a longitudinal direction, and a second longitudinal edge side (8′) parallel thereto and spaced apart therefrom, wherein the film substrate (1) is shaped by shaping means (23) to form a tube, and the two longitudinal edge sides (8, 8′) are in particular welded to one another with the formation of a longitudinal weld seam, wherein a strip (12) is arranged, in the region of the abutment point and/or of the longitudinal weld seam, in the interior (17) of the film substrate (1) shaped to form the tube and is connected, in particular welded, to the longitudinal edge sides (8, 8′) at least in certain regions or portions. According to the invention, prior to the formation of the longitudinal weld seam, at least one longitudinal edge side (8′) is shaped, in particular cut, in such a way that, in the film substrate (1) shaped to form the tube, the longitudinal edge sides (8, 8′) bear against one another, in particular in abutting fashion, radially only in the region of the outer side (2) with at least one tip (9) formed by the shaping operation.

Claims

1. A method for producing flexible tube bodies for packaging tubes from a film substrate (1) having an outer side (2) and having or consisting of at least one weldable plastic layer and comprising a first longitudinal edge side (8) extending in a longitudinal direction and a second longitudinal edge side (8) parallel thereto and spaced apart therefrom, the film substrate (1) being deformed into a tube shape by means of deforming means (23) and the two longitudinal edge sides (8,) being welded to one another, a longitudinal weld seam being formed in the process, a strip (12) being arranged in the area of the joint and/or of the longitudinal weld seam inside (17) the film substrate (1) deformed into the tube shape and being connected to the longitudinal edge sides (8) at least in some areas or sections, wherein, prior to the formation of the longitudinal weld seam, at least one longitudinal edge side (8′) is reshaped in such a manner that the longitudinal edge sides (8, 8′) of the film substrate (1) deformed into the tube shape contact one another radially only in the area of the outer side (2) via at least one tip (9) formed by the reshaping.

2. The method according to claim 1, wherein, in the course of the formation of the longitudinal weld seam, the outer side (2) of the film substrate (1) is connected, in the area of the at least one tip (9) of the longitudinal edge sides (8, 8′) by means of outer heating means (25) after the inner side (13) facing away from the outer side (2) is connected to the strip (12).

3. The method according to claim 1, wherein when the at least one longitudinal edge side (8′) of the film substrate (1) is reshaped, an edge extending obliquely in relation to a thickness direction (D) of the film substrate (1) is produced in each case, the bevel being oriented in such a manner that an opening (15) widening from the outer side (2) to the inner side is produced when the film substrate (1) is deformed into the tube shape.

4. The method according to claim 1, wherein the longitudinal edge sides (8′) are reshaped in such a manner that the opening (15) encloses an angle of 5° to 50°.

5. The method according to claim 1, wherein both longitudinal edge sides (8′) of the film substrate (1) are reshaped, the tips (9) formed by the reshaping thus contacting one another edge to edge, when the film substrate (1) is deformed into the tube shape (2).

6. The method according to claim 1, wherein, in the course of a trimming step, at least one longitudinal edge side (8) is cut in the longitudinal direction (L) by means of a trimming tool, a trimming strip (12.1) separated from the film substrate (1) being produced in the process, wherein the trimming strip is arranged as a strip (12) in the area of the joint of the longitudinal edge sides (8, 8′) and/or of the longitudinal weld seam within the film substrate (1) deformed into the tube shape and is welded to the film substrate (1).

7. The method according to claim 6, wherein during or after the separation of the trimming strip (12.1) from the film substrate (1), prior to the feeding into the inside (17) of the film substrate (1) deformed into the tube shape, at least one side of the trimming strip (12.1) itself is cut in the longitudinal direction (L) by means of trimming tools.

8. The method according to claim 6, wherein between the separation of the trimming strip (12.1) from the film substrate (1) and its insertion into the inside (17) of the film substrate (1) deformed into the tube shape, the trimming strip (12.1) is temporarily stored on a storage means.

9. The method according to claim 1, wherein the strip (12) is heated by means of inner heating means (24a, 24b) and is inserted into the inside (17) of the film substrate (1) deformed into the tube body in a heated and therefore softened state and comes into contact with the longitudinal edge sides (8, 8′), before the outer side (2) is welded to itself.

10. The method according to claim 9, wherein during the connection to the film substrate, the strip (12) is widened transverse to the longitudinal direction (L), the ratio of a width after the connection to the film substrate in relation to an original width thus being greater than 1.5, the strip (12) or trimming strip (12.1) also being flattened transverse to the longitudinal direction (L), at the same time, the ratio of a height after the connection to the film substrate in relation to the original height thus being smaller than 2/3.

11. The method according to claim 1, wherein the strip (12) is placed on a circulating endless belt (21) by means of feeding means (27) and is inserted into the inside (17) of the film substrate (1) deformed into the tube body on the belt (21).

12. A flexible tube body for packaging tubes, made of a film substrate (1) having an outer side (2), the film substrate (1) having or consisting of at least one weldable plastic layer and comprising a first longitudinal edge side (8) extending in a longitudinal direction (L) and a second longitudinal edge side (8) parallel thereto and spaced apart therefrom, the film substrate (1) being deformed into a tube shape by means of deforming means (23) and the two longitudinal edge sides (8) being welded to one another by means of a longitudinal weld seam, a strip (12) being arranged in the area of the joint and/or of the longitudinal weld seam inside (17) the film substrate (1) deformed into the tube shape and being connected, to the longitudinal edge sides (8) at least in some areas or sections, wherein at least one longitudinal edge side (8′) is reshaped, in such a manner that the longitudinal edge sides (8, 8′) of the film substrate (1) deformed into the tube shape are directly connected to one another radially only in the area of the outer side (2) via at least one tip (9) formed by the reshaping.

13. The tube body according to claim 12, wherein the at least one reshaped longitudinal edge side (8′) of the film substrate (1) has a cutting edge which extends obliquely in relation to a thickness direction (D) of the film substrate (1) in each case, the bevel being oriented in such a manner that an opening (15) widening from the outer side (2) to the inner side in the radial direction is produced when the film substrate (1) is deformed into the tube shape.

14. The tube body according to claim 12, wherein the longitudinal edge sides (8′) are reshaped in such a manner that the opening (15) encloses an angle or opening angle of 5° to 50°.

15. The tube body according to claim 12, wherein the opening (15) is partially filled with material of the strip (12) with the exception of the outer side (2) and/or of the outer layer (3).

16. The tube body according to claim 12, wherein both longitudinal edge sides (8′) of the film substrate (1) are reshaped in such a manner that the tips (9) formed by the reshaping are directly connected to one another, edge to edge, radially in the area of the outer side (2) when the film substrate (1) is deformed into the tube shape.

17. The tube body according to claim 12, wherein the strip (12) is formed by a trimming strip (12.1) of the film substrate (1), the trimming strip (12.1) being separated from the film substrate (1) in the course of a trimming process.

18. A device for producing flexible tube bodies for packaging tubes from a film substrate (1) having an outer side (2) and having or consisting of at least one weldable plastic layer and comprising a first longitudinal edge side (8) extending in a longitudinal direction and a second longitudinal edge side (8) parallel thereto and spaced apart therefrom, the film substrate (1) being deformed into a tube shape by means of deforming means (23) and the two longitudinal edge sides being welded to one another, a longitudinal weld seam being formed in the process, a strip (12) being arranged in the area of the joint and/or of the longitudinal weld seam inside (17) the film substrate (1) deformed into the tube shape by means of feeding means and being connected, to the longitudinal edge sides (8) at least in some areas or sections by means of connecting means, further comprising edge reshaping means for reshaping at least one longitudinal edge side (8′) before the longitudinal weld seam is formed, the deforming means (23) for forming the tube shape being realized in such a manner that the longitudinal edge sides (8, 8′) of the film substrate (1) deformed into the tube shape contact one another edge to edge, radially only in the area of the outer side (2) via at least one tip (9) formed by the reshaping.

19. The device according to claim 18, further comprising outer heating means (25) for connecting the outer side (2) of the film substrate (1) in the area of the at least one tips (9) of the longitudinal edge sides (8′) when the longitudinal weld seam is formed, the outer heating means (25) being disposed in such a manner that the connection of the outer side (2) takes place after the inner side (13) facing away from the outer side (2) is connected to the strip (12).

20. The device according to claim 18, wherein the edge reshaping means are disposed and realized in such a manner that an edge, extending obliquely in relation to a thickness direction (D) of the film substrate (1) is produced in each case when the at least one longitudinal edge side (8) of the film substrate (1) is reshaped, the bevel being oriented in such a manner that an opening (15) widening from the outer side (2) to the inner side is produced when the film substrate (1) is deformed into the tube shape.

21. The device according to claim 18, further comprising a trimming tool which cuts a longitudinal edge side (8, 8′) in the longitudinal direction (L), at least in the course of a trimming step, a trimming strip (12.1) separated from the film substrate (1) being produced in the process, wherein the trimming strip (12.1) is arranged as a strip (12) in the area of the joint of the longitudinal edge sides (8, 8′) and/or of the longitudinal weld seam within the film substrate (1) deformed into the tube shape and is welded to the film substrate (1).

22. The device according to claim 18, further comprising inner heating means heating the strip (12), the inner heating means (24) being disposed in such a manner that the strip (12) is inserted into the inside (17) of the film substrate (1) deformed into the tube shape in a heated and therefore softened state by means of feeding means and comes into contact with the inner side (13).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Further advantages, features and details of the invention are apparent from the following description of preferred exemplary embodiments and from the drawings. In the drawings,

[0050] FIG. 1 shows a schematic illustration of a film substrate in the initial state and with indicated separation or cutting planes;

[0051] FIG. 2 shows a schematic illustration of a section of a tube body in the area of the longitudinal weld seam in a first process stage;

[0052] FIG. 3 shows a schematic illustration of a section of a tube body according to the invention in a second process stage;

[0053] FIG. 4 shows a schematic illustration of a device according to the invention for producing tube bodies.

DETAILED DESCRIPTION

[0054] FIG. 1 shows a cross section of a film substrate which can be used in the present invention. Film substrate 1 has a print 31 on an outer side 2. Print 31 is often disposed on an outer layer 3 of film substrate 1; alternatively, it can be disposed below layer 3. Another layer structure 4 composed of one or several layers can be provided below outer layer 3. Layer structure 4 is followed by a barrier layer 5 on the side which faces away from outer side 2. Barrier layer 5 can be followed by another layer structure 6 which is followed by an inner layer 7.

[0055] In the course of the production of the flexible tube body from a film substrate 1, it can be provided, for example, that longitudinal edge sides 8 are reshaped, in particular cut, along longitudinal direction L of film substrate 1 extending into the drawing plane of FIG. 1, the reshaping, in particular cutting, being indicated by corresponding cutting planes S.sub.1 and S.sub.2 in FIG. 1. Original longitudinal sides 8 are transformed into new or cut longitudinal edge sides 8′ by cutting planes S.sub.1 and S.sub.2. It is intended that at least one of cutting planes S.sub.1, S.sub.2 extends obliquely in relation to thickness direction D of film substrate 1 in such a way that they consequently form a tip 9 or tips 9, i.e., acute angles, in the area of outer side 2. As will be explained in more detail below, tips 9 formed by cutting planes S.sub.1 and S.sub.2 in the area of outer side 2 of film substrate 1 ensure that tips 9 can come into edge-to-edge contact to one another and that outer side 2 or outer layer 3 can thus be directly connected to one another in the area of tips 9 with a very low energy input when film substrate 1 is deformed into a tube shape.

[0056] Cutting planes S.sub.1 and S.sub.2 are situated in the printed area of print 31; this ensures that the entire tube is provided with a print. If a preprocessed film substrate is used which has already been trimmed, for example, the cutting along cutting plane S.sub.1 is not necessary.

[0057] Moreover, additional facultative cutting planes S.sub.3 and S.sub.4 can be provided along width B of film substrate 1, wherein cutting planes S.sub.3 and S.sub.4 are used, for example, to produce a strip, in particular a trimming strip 12.1 which can then be inserted into the inside of a film substrate 1 deformed into the tube shape in order to produce the longitudinal weld seam, i.e., to connect the longitudinal edge sides of film substrate 1.

[0058] Cutting plane S.sub.3 is situated outside the printed area of print 31; this ensures that no printing inks contaminate trimming strip 12.1. This is to be ensured for two reasons: Firstly, print 31 should not come into contact with the filling material. Additionally, print 31 reduces the weldability, which means that trimming strip 12.1 cannot be neatly welded to the seam or the final seal or the final seam cannot be produced as intended.

[0059] FIG. 2 shows a section of a flexible tube body according to the invention that is being produced. The section shows the area of longitudinal edge sides 8′ shortly before inner side 13 or inner sides 13 of film substrate 1 are connected to a preferably heated and softened, in particular plastically softened strip 12. In the example of FIG. 2, the strip is any strip which is suitable for the welding process and the connection to film substrate 1. However, a trimming strip 12.1 like the one produced in an exemplary manner in FIG. 1 could also be used as a strip in the situation and the method according to FIG. 2.

[0060] FIG. 2 shows a section of a film substrate 1 deformed into the tube shape. As FIG. 2 shows, corresponding longitudinal edge sides 8′ are disposed edge to edge without overlapping, in particular tips 9 thus contacting one another. This arrangement is provided or enabled by guiding means 10 of the device according to the invention and is maintained for the time being. In the illustration of FIG. 2, a corresponding strip 12 is already arranged below film substrate 1. Alternatively, a trimming strip 12.1 produced, for example, by cutting planes S.sub.3 and S.sub.4 as shown in FIG. 1 could be used. In contrast to film substrate 1, strip 12 can already be heated and softened, in particular in the area of the outer side. However, strip 12 still has a distance from film substrate 1, in particular from inner side 13 of film substrate 1. If strip 12 is a trimming strip produced by the cuts along cutting planes S.sub.3 and S.sub.4 in the illustration of FIG. 1, for example, a rotation of strip 12 by 180° about its longitudinal axis in relation to film substrate may be provided, identical materials or material layers thus facing one another on inner side 13 of film substrate 1 and on outer side 14 of strip 12, the identical materials or material layers thus being connectable, in particular weldable, to one another.

[0061] In a processing or method step which follows the illustration of FIG. 2, a contact and therefore a connection between film substrate 1 and strip 12 is established by reducing, for example continuously reducing, the distance between guiding means 10 and feeding means 27, which preferably comprises a continuously circulating belt 21, in a longitudinal direction perpendicular to the drawing layer, for example. A first contact and a first connection between film substrate 1 and strip 12 can thus be established in the area of contact points K, wherein the contact points expand or widen and become contact surfaces and the material of strip 12 penetrates into opening 15 of the film substrate as a result of the decreasing distance between guiding means 10 and feeding means 27 and the simultaneous pressure increase.

[0062] As the illustration of FIG. 2 shows, an opening 15 forms radially inward from outer side 2 of film substrate 1 when film substrate 1 is in the state deformed into the tube shape, wherein the width of opening 15 increases and is to be considered to be minimal in the area of tips 9. This is because even if tips 9 contact one another, they are not connected to one another, which is why a continuous opening in the film substrate is to be assumed, wherein the opening has a partially minimal or almost disappearing width but is not a recess which only extends over part of the thickness of the film substrate. Opening angle α of opening 15 can enclose an angle between 5° and 50°, preferably between 10° and 40°, for example.

[0063] In a situation of the method according to the invention following the illustration of FIG. 2 and the connection between film substrate 1 and strip 12 described above, a particularly gentle connection requiring little energy can be established between longitudinal edge sides 8′ in the area of outer side 2 of film substrate 1 by outer heating means which are not shown in FIG. 2 and which can be disposed in the area of guiding means 10. If cutting planes S.sub.1 and S.sub.2 are suitably selected, said connection appears to be almost seamless and does not damage or affect said print.

[0064] FIG. 2 also shows that film substrate 1 and thus, in the production according to FIG. 1, strip 12 comprise a barrier layer 5. In the situation or process stage of FIG. 2, longitudinal edge sides 8′ and edge sides 16 of strip 12 have areas where barrier layer 5 is exposed and could thus potentially come into contact with the tube contents to be disposed inside 17 of tube body 18. In general, however, such a contact between barrier layer 5 and inside 17 of the packaging tube or tube filling situated there should be avoided. An appropriate solution is provided in the state of the method and of tube body 18 according to the illustration of FIG. 3.

[0065] As outlined above, a correspondingly direct connection of longitudinal edge sides 8′ has been established on outer side 2 of film substrate 1 or in the area of outer layer 3 of film substrate 1 in the state of FIG. 3. The connection preferably extends over outer layer 3, which has a thickness of 10 μm to 50 μm, for example. However, said connection has been established only after already heated and softened strip 12 had been fed to and pressed against film substrate 1 in the area of longitudinal edge sides 8′ on the inner side or inside 17 of film substrate 1 deformed into the tube shape. As a result of the first-performed and latter step, part of the material of strip 12 has partially penetrated or flowed into opening 15 shown in FIG. 2—in particular since strip 12 had been suitably heated and softened, in particular plastically softened—but only to such depth or such an extent that contacting tips 9 are not displaced, in particular pushed apart. The latter can be achieved by corresponding guiding means of the device (illustrated as guiding means 10 in a highly schematized manner). In the present case, the subsequent connection of longitudinal edge sides 8′ to themselves in the area of outer sides 2, which requires little thermal energy, has additionally led to a direct connection in the area of outer side 2. Furthermore, the material of strip 12 penetrated into opening 15 has caused a covering or sealing of the exposed areas of barrier layer 5. Furthermore, the pressure application to strip 12 and to film substrate 1 has caused a certain degree of melting of strip 12, strip 12 thus having lost approximately half of its original thickness, for example; conversely, however, it has approximately twice the width as prior to the contacting with film substrate 1 and the corresponding pressure application, for example. Since barrier layer 5 is thus more difficult to melt or does not melt at all, this radial thinning and the simultaneous widening of strip 12 have led to the fact that the areas of barrier layer 5 of strip 12 which were still exposed in FIG. 2 have also been covered and thus do not contact inside 17 of tube body 18 anymore.

[0066] Thus, FIG. 3 shows the particularly advantageous connection in the area of the longitudinal weld seam or in the area of longitudinal edge sides 8′. This is because, firstly, there is a direct connection 19 in the area of outer side 2 or in the area of outer layer 3 of film substrate 1, an apparently continuous and seamless print of outer side 2 of film substrate 1 thus being achieved if cutting planes S.sub.1 and S.sub.2 are cut precisely enough, also because the connection is produced using little thermal energy and thus has little to no negative impact on outer side 2 or outer sides 2.

[0067] At the same time, an effective connection has been established both on inner side 13 of film substrate 1 and in the area of opening 15, namely via the material of strip 12, a very stable longitudinal weld seam of tube body 18 thus having been achieved. The mechanical stability is also ensured in that a corresponding part of barrier layer 5 is embedded in strip 12 in the area of longitudinal edge sides 8′, barrier layer 5 contributing to the mechanical stabilization of the longitudinal weld seam. Additionally, the connection is particularly effective between strip 12 and inner side 13 of film substrate 1, because identical materials are connected to one another in this connection, which consequently establish a good and stable connection to one another; in particular, they are consequently well welded to one another. If, instead of the trimming strip, a strip is used whose surfaces can be welded to the inner surface, inner layer 7, or inner side 13, a material which cannot be welded to inner layer 7 can also be selected for outer layer 3.

[0068] FIG. 4 shows a schematic illustration of a device according to the invention. An essentially plane film substrate 1 is fed from the right side, film substrate 1 running to the left in a longitudinal direction and, after leaving device 20, forming a flexible tube body 18 which is still endless and therefore is to be separated and to be connected to a tube head, if applicable. The reshaping of film substrate 1 shown in FIG. 1, in particular the cutting of film substrate 1, can be performed by means of cutting tools, in particular trimming tools (not shown in the illustration of FIG. 4), which have corresponding knives, in particular trimming knives. If a corresponding trimming strip is produced, it can consequently be temporarily stored on a storage means (not shown in FIG. 4) after it has been separated from film substrate 1. The device also comprises two continuously circulating belts 21, 22, part of the entire belt being shown regarding outer belt 22 and inner belt 21.

[0069] Prior to or in parallel with a deforming of film substrate 1 into a corresponding tube shape around a mandrel 26 by means of corresponding deforming means, strip 12, which may be realized as a trimming strip, is fed to inner belt 21. Inner belt 21 and/or strip 12 can be preheated via inner heating means 24a, 24b, strip 12 thus being heated and, preferably plastically, softened before it is inserted into or fed to film substrate 1 deformed into the tube shape on inner belt 21, for example. For example, the deforming means can deform film substrate 1 into a tube shape whose longitudinal edge sides 8′ then contact one another without overlapping in the area of the tip or of the tips of outer side 2, as shown, for example, in FIG. 2. In a subsequent step, the above-described connection between soft, warm strip 12 and film substrate 1 takes place, for example from initial contact point 28, starting from which a contact exists, preferably at contact points K, and starting from which the contact or the contact surface is increased in longitudinal direction L by corresponding contact pressure. After this connection has been established and strip 12 is cooling down and hardening again or has cooled down and hardened in a deformed shape partially flowed into the opening, a corresponding energy input is ensured by outer heating means 25, the energy input leading to a direct connection of longitudinal edge sides 8′ to one another in the area of outer side 2 of film substrate 1.

REFERENCE SIGNS

[0070] 1 film substrate

[0071] 2 outer side

[0072] 3 outer layer

[0073] 4 layer structure

[0074] 5 barrier layer

[0075] 6 layer structure

[0076] 7 inner layer

[0077] 8, 8′ longitudinal edge sides

[0078] 9 tip

[0079] 10 guiding means

[0080] 12 strip

[0081] 12.1 trimming strip

[0082] 13 inner side

[0083] 14 outer side

[0084] 15 opening

[0085] 16 edge sides

[0086] 17 inside

[0087] 18 tube body

[0088] 19 connection

[0089] 20 device

[0090] 21 belt

[0091] 22 belt

[0092] 24 inner heating means

[0093] 25 outer heating means

[0094] 26 mandrel

[0095] 27 feeding means

[0096] 28 contact point

[0097] 31 print

[0098] A opening angle

[0099] D thickness direction

[0100] B width

[0101] L longitudinal direction

[0102] K contact point

[0103] A opening angle

[0104] S1, S2 cutting plane

[0105] S3, S4 cutting plane