Patent ID: 12251886

DETAILED DESCRIPTION

FIG.1shows a cross section of a film substrate which can be used in the present invention. Film substrate1has a print31on an outer side2. Print31is often disposed on an outer layer3of film substrate1; alternatively, it can be disposed below layer3. Another layer structure4composed of one or several layers can be provided below outer layer3. Layer structure4is followed by a barrier layer5on the side which faces away from outer side2. Barrier layer5can be followed by another layer structure6which is followed by an inner layer7.

In the course of the production of the flexible tube body from a film substrate1, it can be provided, for example, that longitudinal edge sides8are reshaped, in particular cut, along longitudinal direction L of film substrate1extending into the drawing plane ofFIG.1, the reshaping, in particular cutting, being indicated by corresponding cutting planes S1and S2inFIG.1. Original longitudinal sides8are transformed into new or cut longitudinal edge sides8′ by cutting planes S1and S2. It is intended that at least one of cutting planes S1, S2extends obliquely in relation to thickness direction D of film substrate1in such a way that they consequently form a tip9or tips9, i.e., acute angles, in the area of outer side2. As will be explained in more detail below, tips9formed by cutting planes S1and S2in the area of outer side2of film substrate1ensure that tips9can come into edge-to-edge contact to one another and that outer side2or outer layer3can thus be directly connected to one another in the area of tips9with a very low energy input when film substrate1is deformed into a tube shape.

Cutting planes S1and S2are situated in the printed area of print31; 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 S1is not necessary.

Moreover, additional facultative cutting planes S3and S4can be provided along width B of film substrate1, wherein cutting planes S3and S4are used, for example, to produce a strip, in particular a trimming strip12.1which can then be inserted into the inside of a film substrate1deformed into the tube shape in order to produce the longitudinal weld seam, i.e., to connect the longitudinal edge sides of film substrate1.

Cutting plane S3is situated outside the printed area of print31; this ensures that no printing inks contaminate trimming strip12.1. This is to be ensured for two reasons: Firstly, print31should not come into contact with the filling material. Additionally, print31reduces the weldability, which means that trimming strip12.1cannot be neatly welded to the seam or the final seal or the final seam cannot be produced as intended.

FIG.2shows a section of a flexible tube body according to the invention that is being produced. The section shows the area of longitudinal edge sides8′ shortly before inner side13or inner sides13of film substrate1are connected to a preferably heated and softened, in particular plastically softened strip12. In the example ofFIG.2, the strip is any strip which is suitable for the welding process and the connection to film substrate1. However, a trimming strip12.1like the one produced in an exemplary manner inFIG.1could also be used as a strip in the situation and the method according toFIG.2.

FIG.2shows a section of a film substrate1deformed into the tube shape. AsFIG.2shows, corresponding longitudinal edge sides8′ are disposed edge to edge without overlapping, in particular tips9thus contacting one another. This arrangement is provided or enabled by guiding means10of the device according to the invention and is maintained for the time being. In the illustration ofFIG.2, a corresponding strip12is already arranged below film substrate1. Alternatively, a trimming strip12.1produced, for example, by cutting planes S3and S4as shown inFIG.1could be used. In contrast to film substrate1, strip12can already be heated and softened, in particular in the area of the outer side. However, strip12still has a distance from film substrate1, in particular from inner side13of film substrate1. If strip12is a trimming strip produced by the cuts along cutting planes S3and S4in the illustration ofFIG.1, for example, a rotation of strip12by 180° about its longitudinal axis in relation to film substrate may be provided, identical materials or material layers thus facing one another on inner side13of film substrate1and on outer side14of strip12, the identical materials or material layers thus being connectable, in particular weldable, to one another.

In a processing or method step which follows the illustration ofFIG.2, a contact and therefore a connection between film substrate1and strip12is established by reducing, for example continuously reducing, the distance between guiding means10and feeding means27, which preferably comprises a continuously circulating belt21, in a longitudinal direction perpendicular to the drawing layer, for example. A first contact and a first connection between film substrate1and strip12can 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 strip12penetrates into opening15of the film substrate as a result of the decreasing distance between guiding means10and feeding means27and the simultaneous pressure increase.

As the illustration ofFIG.2shows, an opening15forms radially inward from outer side2of film substrate1when film substrate1is in the state deformed into the tube shape, wherein the width of opening15increases and is to be considered to be minimal in the area of tips9. This is because even if tips9contact 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 opening15can enclose an angle between 5° and 50°, preferably between 10° and 40°, for example.

In a situation of the method according to the invention following the illustration ofFIG.2and the connection between film substrate1and strip12described above, a particularly gentle connection requiring little energy can be established between longitudinal edge sides8′ in the area of outer side2of film substrate1by outer heating means which are not shown inFIG.2and which can be disposed in the area of guiding means10. If cutting planes S1and S2are suitably selected, said connection appears to be almost seamless and does not damage or affect said print.

FIG.2also shows that film substrate1and thus, in the production according toFIG.1, strip12comprise a barrier layer5. In the situation or process stage ofFIG.2, longitudinal edge sides8′ and edge sides16of strip12have areas where barrier layer5is exposed and could thus potentially come into contact with the tube contents to be disposed inside17of tube body18. In general, however, such a contact between barrier layer5and inside17of 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 body18according to the illustration ofFIG.3.

As outlined above, a correspondingly direct connection of longitudinal edge sides8′ has been established on outer side2of film substrate1or in the area of outer layer3of film substrate1in the state ofFIG.3. The connection preferably extends over outer layer3, which has a thickness of 10 μm to 50 μm, for example. However, said connection has been established only after already heated and softened strip12had been fed to and pressed against film substrate1in the area of longitudinal edge sides8′ on the inner side or inside17of film substrate1deformed into the tube shape. As a result of the first-performed and latter step, part of the material of strip12has partially penetrated or flowed into opening15shown inFIG.2—in particular since strip12had been suitably heated and softened, in particular plastically softened—but only to such depth or such an extent that contacting tips9are not displaced, in particular pushed apart. The latter can be achieved by corresponding guiding means of the device (illustrated as guiding means10in a highly schematized manner). In the present case, the subsequent connection of longitudinal edge sides8′ to themselves in the area of outer sides2, which requires little thermal energy, has additionally led to a direct connection in the area of outer side2. Furthermore, the material of strip12penetrated into opening15has caused a covering or sealing of the exposed areas of barrier layer5. Furthermore, the pressure application to strip12and to film substrate1has caused a certain degree of melting of strip12, strip12thus 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 substrate1and the corresponding pressure application, for example. Since barrier layer5is thus more difficult to melt or does not melt at all, this radial thinning and the simultaneous widening of strip12have led to the fact that the areas of barrier layer5of strip12which were still exposed inFIG.2have also been covered and thus do not contact inside17of tube body18anymore.

Thus,FIG.3shows the particularly advantageous connection in the area of the longitudinal weld seam or in the area of longitudinal edge sides8′. This is because, firstly, there is a direct connection19in the area of outer side2or in the area of outer layer3of film substrate1, an apparently continuous and seamless print of outer side2of film substrate1thus being achieved if cutting planes S1and S2are cut precisely enough, also because the connection is produced using little thermal energy and thus has little to no negative impact on outer side2or outer sides2.

At the same time, an effective connection has been established both on inner side13of film substrate1and in the area of opening15, namely via the material of strip12, a very stable longitudinal weld seam of tube body18thus having been achieved. The mechanical stability is also ensured in that a corresponding part of barrier layer5is embedded in strip12in the area of longitudinal edge sides8′, barrier layer5contributing to the mechanical stabilization of the longitudinal weld seam. Additionally, the connection is particularly effective between strip12and inner side13of film substrate1, 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 layer7, or inner side13, a material which cannot be welded to inner layer7can also be selected for outer layer3.

FIG.4shows a schematic illustration of a device according to the invention. An essentially plane film substrate1is fed from the right side, film substrate1running to the left in a longitudinal direction and, after leaving device20, forming a flexible tube body18which is still endless and therefore is to be separated and to be connected to a tube head, if applicable. The reshaping of film substrate1shown inFIG.1, in particular the cutting of film substrate1, can be performed by means of cutting tools, in particular trimming tools (not shown in the illustration ofFIG.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 inFIG.4) after it has been separated from film substrate1. The device also comprises two continuously circulating belts21,22, part of the entire belt being shown regarding outer belt22and inner belt21.

Prior to or in parallel with a deforming of film substrate1into a corresponding tube shape around a mandrel26by means of corresponding deforming means, strip12, which may be realized as a trimming strip, is fed to inner belt21. Inner belt21and/or strip12can be preheated via inner heating means24a,24b, strip12thus being heated and, preferably plastically, softened before it is inserted into or fed to film substrate1deformed into the tube shape on inner belt21, for example. For example, the deforming means can deform film substrate1into a tube shape whose longitudinal edge sides8′ then contact one another without overlapping in the area of the tip or of the tips of outer side2, as shown, for example, inFIG.2. In a subsequent step, the above-described connection between soft, warm strip12and film substrate1takes place, for example from initial contact point28, 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 strip12is 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 means25, the energy input leading to a direct connection of longitudinal edge sides8′ to one another in the area of outer side2of film substrate1.

REFERENCE SIGNS

1film substrate2outer side3outer layer4layer structure5barrier layer6layer structure7inner layer8,8′ longitudinal edge sides9tip10guiding means12strip12.1trimming strip13inner side14outer side15opening16edge sides17inside18tube body19connection20device21belt22belt24inner heating means25outer heating means26mandrel27feeding means28contact point31printA opening angleD thickness directionB widthL longitudinal directionK contact pointA opening angleS1, S2cutting planeS3, S4cutting plane