DE4425861A1 - Filled tube end sealing close to prod. without heat or contaminating - Google Patents

Abstract

The tubular vessel has a thermoplastic inner wall, which is to be sealed at the open end, over the already-filled product. The seal position is spaced from the filling end, and runs in a plane, perpendicular-, or slanted to the tube axis, on its inner wall. The tube is flattened and the walls are pressed together, at the same time forming an open slit cavity between them, towards the outer edge. This allows heat to be supplied to the exposed inner walls, which are pressed together to complete the weld. Also claimed are: (a) variations on the method of sealing, and (b) suitable appts. for it.

Description

State of the art

The invention relates to methods for closing the Filling end of a tubular container, in particular for Closing the filling end of one to be formed into a tube Container. In a variant, the invention relates to a method of the aforementioned type, in which the container moreover at least consists of thermoplastic material on its inner wall, according to the preamble of claim 1.

To close the filling end of a tube shaping tubular container by welding its filling with a product is e.g. B. according to DE-C-34 01 959 known, a nozzle device with a radially directed Hot gas escapes into the filling opening of the Move hollow body and a defined, in a to Longitudinal axis of the container lying transversely level Heat the inner wall portion of the hollow body to adhere to it  then the container in the heated area Lay the inner wall section flat and lay it flat opposite wall parts for the purpose of welding to press against each other.

In the described method, the outer wall of the Container essentially unharmed because the temperature of the mentioned inner wall section opposite area of the Outer wall is significantly lower than the temperature in the actual, internal welding area. Visually unsightly Swelling is avoided because it is not as in the case of externally supplied heat to an uncontrolled flow of the Materials is coming.

In contrast to what can also be done from the outside Welding the filling opening, i.e. the filling end, one only from thermoplastic material such as PVC Existing container comes the procedure described above especially considered for welding multi-layer existing containers, especially those More layered materials that have an insert made of metal foil and on the the inside of the container facing a coating or Thermoplastic film included.

A disadvantage of the method described, however, is that despite the diagonally upwards - with a directional component the filling end of the container facing out of the nozzle escaping hot gas cannot be avoided that hot gas also down towards the in the container filled product arrives, so that this due to the heat influence is changed in its quality. This danger exists even more than for the purpose of an economic material use the necessary and intended for the locking, wall area of the Container is chosen as short as possible.  

task

The aim of the present invention is the possibility of a adverse influence on the filled in the container Product as a result of the closure of the container prevent measures taken with certainty. For the Case of closing the container by welding the concerned, from the inside heated wall areas of the Container should in particular prevent hot gas - or hot air - comes into contact with the product or also only in its immediate vicinity.

solution

A possible solution to the above, the use of Hot gas or hot air for welding Closing a container-related task is in the kenn drawing part of claim 1 specified. The dependent ones Claims 2 to 6 indicate preferred further refinements.

Claim 7 calls a further, basic solution for a closing a container according to the invention, namely by Gluing. The dependent claims 8 to 11 give for this detailed possibilities.

Another basic solution for the case of through The sealing of the container takes place in the weld Claim 12 indicated, with references in the dependent Claims 13 to 15 on preferred options for this.

Claim 17 finally calls a particularly advantageous Measure to achieve the goal pursued by the invention.

Claim 18 relates to one for performing the method according to Claim 1 intended, preferred device to the further advantageous features and refinements of claims 19 to  23 can be seen.

Claim 24 gives the device features for the Implementation of the measures mentioned in claim 17, while claim 25 is a preferred embodiment of this Features called.

benefits

In the case of a process according to the invention closing a tubular container, in particular a container to be formed into a tube certainly prevents the product filled in the container due to the special features of the lock Process steps are changed in quality, be it under the influence of hot gas or hot air, be it through to Welding or gluing materials used.

Explanation of the invention using an exemplary embodiment

Referring to Figs. 1 and 2 of the drawing method of the invention and two preferred for carrying out this method useful devices are described in detail below.

Show it

Fig. 1 shows an embodiment of an inventive device in side view in schematic illustration and is limited to the essential features

Fig. 2 shows another embodiment of a device according to the invention in a side view in a schematic representation and limited to the essential features.

The device according to FIG. 1 has a carrier 1 for pre-pressing jaws 2 and 3, which can be controlled against each other, and main pressing jaws 4 and 5 . While the pre-pressing jaws 2 , 3 are fastened to the lower end of an operating lever 6 and 7 , the main pressing jaws 4 , 5 are fastened to the lower end of an operating lever 8 and 9 , respectively.

The actuating levers 8 , 9 are mounted so as to be pivotable about a common geometric pivot axis 10 on a main bearing located on the support 1 and designated 15 ; the actuating levers 6 , 7 are each pivotably mounted on a sub-bearing 13 or 14 about a separate geometric pivot axis 11 or 12 . The geometric pivot axes 10 , 11 and 12 run parallel to one another and are preferably in a horizontal plane. The common geometric pivot axis 10 of the main press jaws 4 , 5 lies between the geometric pivot axes 11 and 12 of the pre-press jaws 2 and 3 .

On the carrier 1 or on the main bearing 15 , the actuating element (not shown in more detail) of a servomotor 16 for the actuating levers 8 , 9 of the main pressing jaws 4 , 5 is supported , while for the actuating levers 6 , 7 of the preliminary pressing jaws 2 , 3 a servomotor 17 and 18, respectively is provided. The servomotors 16 , 17 and 18 are preferably designed as pneumatic or hydraulic piston-cylinder arrangements.

Between the pre-pressing jaws 2 , 3 and the main pressing jaws 4 , 5 , a nozzle device 19 is fastened to the carrier 1 below the main bearing 15, which serves to dispense a hot gas flow directed downwards towards the intermediate space designated by 20 .

On the opposite side of the nozzle device 19 of the pre-pressing jaws 2 , 3 and the main pressing jaws 4 , 5 - ie below the carrier 1 - there are conveying means 21 , for. B. in the form of a rotating drivable star or a linearly moving link belt, the receiving means 22 to carry and promote the occasional receiving of containers 23 to be closed. The conveying means 21 move the receptacle 22 preferably in a horizontal plane, the container 23 being transported with the filling end upwards, preferably with the longitudinal longitudinal axis 24 of the container 23 , and in this position the filling end labeled 25 of each container 23 is closed.

The mode of operation of the device according to FIG. 1 is as follows:
Intermittently controlled, the conveying means 21 promotes the receiving means 22 , each with a container 23 therein, previously filled with a product, into the space located just below the outlet of the nozzle device 19 . The wall of the container 23 , which at this point is still approximately circular in cross-section, is first laid flat by means of the preferably wedge-shaped pre-pressing jaws 2 , 3 , moreover the pre-pressing jaws are pressed against one another with a certain force, so that the interior of the container is at least exposed to the external atmosphere is essentially complete. This force is expediently chosen to be so great that, in addition, there is also a certain flow of the wall material located on the inner wall, and only on this, for example a coating made of polyethylene. The latter causes the container wall to expand again at a relatively short distance from the position assumed by the pre-pressing jaws 2 , 3 due to internal material tensions, while an expansion taking place without such support by the external pressure mentioned only occurs in comparison to the larger distance is to be expected.

The expansion mentioned has - immediately after the position assumed by the pre-pressing jaws 2 , 3 - the shape of an elongated gap narrowing from the filling end 25 in the direction of the pre-pressing jaws 2 , 3 . In the gap-shaped space thus formed, not shown in the drawing, a hot gas or gas mixture, preferably hot air, is then blown in with the aid of the nozzle device 19 such that the material of the inner container wall is approximately in an inner wall section adjoining the position of the pre-pressing jaws heated until melting begins. Then the supply of the hot gas is expediently - at least essentially - interrupted and the main pressing jaws - with this part of the container wall also laid flat - is moved towards the outer wall section of the container wall opposite the mentioned inner wall section and then presses the wall parts located at this point with a predetermined amount or predeterminable force and against one another over a predetermined or predeterminable period of time, as a result of which the thermoplastic material located in the region of the mentioned inner wall section welds the two wall parts of the container 23 thus formed.

It should also be mentioned that the nozzle device by appropriate arrangement of nozzle bores can be performed that the emerging hot gas or hot air current the expansion of the wall described above in immediate close proximity to the position of the pre-pressing jaws supported.

Even if this together with the described mode of action the device according to the drawing explained method as is preferred to be used, but so are the im essentially containing a similar inventive concept Process according to claims 4 and 9 also advantageous applicable.

The device shown in FIG. 1 is of course only one - albeit a preferred one - of several possibilities for the objective realization of the inventive concept; with knowledge of the invention, it is not difficult for a person skilled in the art to design further constructive embodiments without requiring a special inventive effort.

FIG. 2 shows a device in which, in contrast to the device according to FIG. 1, devices 26 and 27 with a tongue-like retaining element 28 and 29 are provided for the opposite wall parts, designated 30 and 31 , respectively. In addition, the designated with 32 and 33 Vorpreßbacken and 34 and 35 designated main press jaws - in contrast to the corresponding components of the device of FIG. 1 - controlled linearly displaceable in a manner not shown.

The mode of operation of the device according to FIG. 2 is as follows:
In the under the nozzle device 19 , still open filler 25 of a container 23 , the free ends of the tongue-like, an angle of about 60 ° including back retaining elements 28 , 29 are moved to a certain extent, for example about 5 mm in the vertical direction by appropriate activation of the devices 26 , 27 acting as servomotors for the retaining elements 28 , 29 . Subsequently - or also approximately simultaneously with it - the pre-pressing jaws 32 , 33 are moved from the position shown in dashed lines towards the wall 36 of the container 23 and further up to the position shown in FIG. 2 by the continuous line. This movement of the pre-pressing jaws 32 , 33 causes the container 23 to be laid flat in the area in question; the wall parts 30 , 31 which are formed thereby lie under the internal tension of the material of the wall 36 of the container 23 against the free ends of the retaining elements 28 , 29 and thus take the angle of approximately 60 ° between the retaining elements 28 , 29 a. This ensures that the widening of the free (upper in the drawing) end of the container 23 forming the above-mentioned gap-shaped space, designated 37 , has an optimal cross section for the use of hot gas or the like. Already during the blowing in of the hot gas or the hot air, the retaining elements 28 , 29 can be withdrawn, and then the main pressing jaws 34 , 35 are moved towards the wall parts 30 , 31 thus prepared for welding and press them with a predetermined pressure for a predetermined period of time for welding them together.

Of course, these or similar retention elements also work in conjunction with a device in which Airtight connection of the wall parts uses an adhesive or laser or infrared radiation becomes airtight Joining the wall parts by fusion welding applied becomes.

Reference list

1 carrier
2 pre-press jaw
3 pre-press jaw
4 main press jaw
5 main press jaw
6 actuating lever (for the pre-pressing jaw 2 )
7 operating lever (for the pre-pressing jaw 3 )
8 operating levers (for the main press jaw 4 )
9 operating lever (for the main press jaw 5 )
10 geometric swivel axis (for the main press jaws 4 , 5 )
11 geometric pivot axis (for the pre-pressing jaw 2 )
12 geometric swivel axis (for the pre-pressing jaw 3 )
13 sub-bearings (for the operating lever 6 )
14 sub-bearings (for the operating lever 7 )
15 main bearings (for the actuating levers 8 , 9 )
16 servomotor (for the actuating levers 8 , 9 )
17 servomotor (for the actuating lever 6 )
18 servomotor (for the actuating lever 7 )
19 nozzle device (for dispensing hot gas or hot air)
20 space (between the main press jaws 4 , 5 )
21 Funding means (for receiving means 22 with containers 23 )
22 receiving means (for container 23 )
23 containers
24 longitudinal axis (of a container 23 )
25 filling end (of a container 23 )
26 device (for tongue-like retaining element 28 )
27 device (for tongue-like retaining element 29 )
28 retaining element, tongue-like
29 retaining element, tongue-like
30 wall part (the wall 37 of the container 23 )
31 wall part (the wall 37 of the container 23 )
32 pre-pressing jaw
33 pre-press jaw
34 main press jaw
35 main press jaw
36 wall (of the container 23 )
37 expansion (to form a gap-shaped space)

Claims (26)

1. Method for closing the filling end of a tubular container from a material consisting of thermoplastic at least on its inner wall, in particular for closing the filling end of a container to be formed into a tube,

• a) in which a closed inner wall section of the container, which is located at a distance from the filling end and lies in a plane that is transverse or oblique to the longitudinal axis of the container, is exposed to a heat effect that enables subsequent pressure welding,
• b) and then the container is laid flat in the area of the mentioned inner wall section for the purpose of welding and the flat wall parts are pressed against each other,

characterized,

• c) that first the container on one in a certain Distance from the filler located flat and the flat wall parts against each other are pressed towards the end of the filling opening, to the named place of the flat Container immediately adjacent slit-shaped Space between the opposite Wall parts,  
• d) that then the inner surfaces of the gap-shaped space enclosing wall parts heat is supplied to the welding enables heating of the thermo plastic material of the inner wall in this area
• e) and that finally the to the named place of the flat container immediately following, the mentioned wall parts forming a gap-like space be pressed against each other for pressure welding.

2. The method according to claim 1, characterized in that Hot gas or hot air is blown into the gap-shaped space becomes. 3. The method according to claim 1, characterized in that a gas flame is directed into the gap-shaped space. 4. The method according to claim 1, characterized in that Infrared or near-infrared radiation in the slit-shaped Room is directed. 5. The method according to claim 1, characterized in that the wall parts with the place of the flat container of such a force that the Material of the inner wall of the container at this point below the pressure begins to flow. 6. The method according to claim 5, characterized in that the material of the inner wall of the container is one at the same time exposed to certain heat. 7. Method for closing the filling end of a tubular container, in particular for closing the filling end of a container to be formed into a tube,

• a) by first laying the container flat at a point at a certain distance from the filling end and pressing the flat wall parts against one another to form a gap-like space between the opposing wall parts that opens towards the filling end and immediately adjoins the aforementioned position of the flat container ,
• b) adhesive is then introduced into the gap-shaped space mentioned,
• c) and finally the wall parts directly adjoining the said location of the laid-down container and forming the aforementioned gap-shaped space are pressed against one another for gluing.

8. The method according to claim 7, characterized in that One-component adhesive is used. 9. The method according to claim 7, characterized in that Two-component adhesive is used. 10. The method according to claim 7, characterized in that Hot melt adhesive is used which is in liquid state the mentioned gap-shaped space is introduced. 11. The method according to claim 7, characterized in that Hot melt adhesive is used which is in the solid state in the introduced mentioned gap-shaped space and one Hot gas or hot air flow is exposed. 12. Method for closing the filling end of a tubular container, in particular for closing the filling end of a container to be formed into a tube,

• a) that the container is first laid flat at a point near the filling end and the flat wall parts are pressed against each other,
• b) and that then the pressed against each other wall parts from an approximately in the plane of the longitudinal axis of the container, preferably approximately parallel to the longitudinal axis of the container by means of radiated heat or when striking matter in heat convertible energy in the contact area by fusion welding with each other get connected.

13. The method according to claim 12, characterized in that the heat by means of a hot gas or hot air jet the wall parts is delivered. 14. The method according to claim 12, characterized in that the heat by means of a gas flame on the wall parts is delivered. 15. The method according to claim 12, characterized in that the heat by means of a laser beam on the wall parts is released, the energy of which strikes the Material of the wall parts is converted into heat. 16. The method according to claim 12, characterized in that the heat by means of infrared or near-infrared radiation the wall parts is delivered. 17. The method according to claim 1, 7 or 12, characterized in that to support the formation of the filling end ( 25 ) of the container ( 23 ) opening, in the place of the flat container ( 23 ) immediately adjoining gap-shaped space (Widening 37) between the opposing wall parts ( 30 , 31 ) at least during the process of laying flat, preferably for a certain time beyond, on the mutually opposing two wall parts ( 30 , 31 ) is acted in a reserved manner such that an optimal cross section of the gap-shaped space (widening 37 ) is formed for the supply of heat or the supply of an adhesive. 18. Device for performing the method according to claim 1 or 7, characterized by

• a) two mutually controllable pre-pressing jaws ( 2 , 3 ) which can be pivoted on a support ( 1 ) about parallel geometric pivot axes ( 11 , 12 ) and lie in a horizontal plane to lay the filling end ( 25 ) of the tubular container ( 23 ) and exerting a certain pressure on the flat, adjacent wall parts,
• b) furthermore two mutually controllable main press jaws (on the carrier ( 1 ) mentioned, which can be pivoted parallel to one another and to the geometric pivot axes ( 11 , 12 ) of the pre-pressing jaws ( 2 , 3 ) and lie in a horizontal plane (pivot axis 10 )) 4 , 5 ),
• c) operating lever ( 6 , 7 or 8 , 9 ) for the pre-pressing jaws ( 2 , 3 ) or the main pressing jaws ( 4 , 5 ),
• d) drive means (actuators 16, 17, 18 ) for the actuating levers ( 6 , 7 , 8 and 9 ),
• e) receiving means ( 22 ) for occasionally picking up containers ( 23 ) which are open,
• f) conveying means ( 21 ) for the receiving means ( 22 ) for conveying the receiving means ( 22 ) in a horizontal plane into the effective range of the pre-pressing jaws ( 2 , 3 ) or main pressing jaws ( 4 , 5 ),
• g) on the one side of the receiving means ( 22 ) opposite the side of the main pressing jaws ( 4 , 5 ) in the vicinity of the gap ( 20 ) formed by the main pressing jaws ( 4 , 5 ) during the welding process and enclosing the wall parts mentioned and centrally on the carrier ( 1 ) arranged nozzle device ( 19 ) for controllably dispensing a hot gas or hot gas mixture, in particular hot air,
• h) and electrical and / or fluidic control means for controlling the drive means (actuators 16, 17, 18 ) of the pre-pressing or main pressing jaws ( 2 , 3 or 4 , 5 ), the conveying means ( 21 ) and the nozzle device ( 19 ).

19. The apparatus according to claim 18, characterized in that the pre-pressing jaws ( 2 , 3 ) have a heating device. 20. The apparatus according to claim 18, characterized in that the entire opening cross section of the openings provided for the escape of the hot gas or the hot air of the nozzle device ( 19 ) is variable to a predetermined extent. 21. The apparatus according to claim 18, characterized in that the geometric pivot axes ( 11 , 12 or 10 ) of pre-press jaws ( 2 , 3 ) and main press jaws ( 4 , 5 ) lie approximately in one plane. 22. The apparatus according to claim 18 or 21, characterized in that the geometric pivot axes ( 10 ) of the main pressing jaws ( 4 , 5 ) between the geometric pivot axes ( 11 , 12 ) of the pre-pressing jaws ( 2 , 3 ). 23. The device according to claim 22, characterized in that the main pressing jaws ( 4 , 5 ) about a common pivot axis ( 10 ) are pivotable. 24. Device for performing the method according to claim 17, characterized by

• a) two mutually controllable pre-pressing jaws ( 32 , 33 ) for laying the filling end ( 25 ) of the tubular container ( 23 ) flat and exerting a certain pressure on the flat, adjacent wall parts ( 30 , 31 ),
• b) furthermore two mutually controllable main pressing jaws ( 34 , 35 ),
• c) actuating means for the pre-pressing jaws or the main pressing jaws ( 32 , 33 or 34 , 35 ),
• d) drive means for the actuating means,
• e) receiving means ( 22 ) for occasionally picking up containers ( 23 ) which are open,
• f) conveying means ( 21 ) for the receiving means ( 22 ) for conveying the receiving means ( 22 ) into the effective range of the pre-pressing jaws ( 32 , 33 ) or the main pressing jaws ( 34 , 35 ),
• g) one on the side of the main pressing jaws ( 34 , 35 ) opposite the receiving means ( 22 ) in the vicinity of the intermediate space ( 20 ) formed by the main pressing jaws ( 34 , 35 ) during the welding process and including the mentioned wall parts and a dispensing device provided in the center thereof (Nozzle device 19 ) for the controllable delivery of a hot gas or hot gas mixture, in particular special hot air, an adhesive or a laser beam,
• h) and bake electrical and / or fluidic control means for controlling the drive means of the pre-press or main press ( 32 , 33 or 34 , 35 ), the conveying means ( 21 ) and the dispensing device (nozzle device 19 ),
• i) and at least one tongue-like retaining element ( 28 , 29 ), the free end of which for a predetermined period of time in the space between the formation of a gap-shaped space (expansion 37 ) for blowing in hot gas or hot air, adding an adhesive or irradiating a laser beam Prepress jaws ( 32 , 33 ) and dispenser (nozzle device 19 ) on the one hand and main press jaws ( 34 , 35 ) on the other hand can be controlled in such a way that the formation of a gap-shaped space (expansion 37 ) for blowing in hot air is facilitated while retaining at least one of the two at the Filling ( 25 ) adjoining wall parts ( 30 , 31 ) at least during the process of laying the container ( 23 ) flat, preferably for a certain time beyond.

25. The device according to claim 19, characterized in that two angled tongue-like retaining elements ( 28 , 29 ) are provided for retaining both the filling end ( 25 ) adjoining wall parts ( 30 , 31 ).