WO1998036970A1

WO1998036970A1 - Device for the sterile sealing of a liquid-filled pack

Info

Publication number: WO1998036970A1
Application number: PCT/EP1997/006571
Authority: WO
Inventors: Peter Josef Martin
Original assignee: Tetra Laval Holdings & Finance S.A.
Priority date: 1997-02-20
Filing date: 1997-11-25
Publication date: 1998-08-27
Also published as: AU5655098A; DE19706722A1

Abstract

The invention relates to a device for sealing a pack filled with liquid in a sterile manner under sterile conditions in a clean room (12). Said device comprises side walls (16, 17), a floor (13) and an upper wall (18). A conveyor for transporting the upright packs traverses the clean room (12) by means of an inlet opening (21) and an outlet opening (23) situated in opposite side walls (16, 17). In addition, the invention provides for cleaning devices (24) and sealing tools to be situated inside the clean room (12). So that the clean room (12) is easier to clean and can be kept sterile by simpler measures the invention provides for the sealing tools to be fastened to a standard frame (25) with their drive mechanisms (33), for said tools to be housed in the clean room (12) together with the standard frame, and for the surfaces (13, 16-18) of the clean room (12) to comprise special steel.

Description

Device for aseptically closing a plastic packaging

The invention relates to a device for closing a sterile filled plasticizer pack under aseptic conditions in a clean room with side walls, bottom and top wall, in which a conveyor for transporting the upright pack crosses the clean room with the help of an inlet opening and an outlet opening in opposite side walls, with cleaning devices and with closing tools.

There are almost no devices with which plastic packaging can be filled aseptically and also sealed under aseptic conditions. Sealing by known methods is carried out, for example, by sealing together, the packs being those made of plastic or those made of plastic-coated carrier material, such as paper. To seal such packages aseptically, the working environment would not only have to be made sterile, but also kept sterile. At the same time, tools would have to be moved in relation to a frame or frame when closing. The known devices have a large number of individual parts, for example drives, such as shafts, gears, control cams, which as a rule cannot be arranged in a clean room and can work there. The lubricants that are indispensable here require a non-aseptic atmosphere.

When welding plasticizer packs in other devices known in practice, hot air has been generated and placed on the seam surfaces to be joined together in order to make them hot and weldable. Such heating cannot take place in a germ-free room, because the hot air itself is not germ-free, and facilities in a smaller, closed room would overheat considerably. Very large clean rooms, on the other hand, can only be made sterile or kept germ-free with great difficulty.

The invention is therefore based on the object of improving a device of the type mentioned at the outset in such a way that the clean room is easier to clean and can be kept sterile with simpler measures.

This object is achieved in that the closing tools are attached with their drives to a unit frame and are housed with this in the clean room and that the surfaces of the clean room have stainless steel. On a unitary framework that is preferably made of stainless steel, all closing tools are attached together with their drives. A module is thus created, so to speak, that can be easily brought into and removed from the clean room. It can also be moved as a unit within the clean room. In conjunction with the easily cleanable stainless steel, the closing device according to the invention is thereby easier to clean and also to keep it germ-free.

It is particularly advantageous according to the invention if a drive shaft, cam and gear are arranged under the floor of the clean room and drives for the package conveyor pass through the floor in a housing. The machine drive supplies the drive units, such as gears, shafts, cams and the like, which are arranged outside the clean room under the floor. There they can be easily accessible and lubricated if necessary, without affecting the atmosphere in the clean room. There are only a few driven parts inside the clean room, which are encapsulated. If it is appropriate to move the drive for the package conveyor into the area of the clean room, then this drive can reach through the floor into the clean room in a housing that is completely sealed from the clean room. The bearings of the moving parts of the packaging conveyor are in turn encapsulated. Lubrication of the same during operation is not necessary.

To further facilitate cleaning, in an advantageous embodiment of the invention, the cleaning devices have nozzles for the supply of acids, alkalis, water or other liquids. Due to the execution of the individual parts and also the inner walls of the clean room in stainless steel, the nozzles can be used for quick and thorough cleaning if necessary. Of course, you can also spray peroxide in different concentrations, as is done in filling chambers for filling empty packaging with aseptic filling. It is expedient to provide a fully encapsulated filling chamber in the direction of transport of the package conveyor in front of the cleaning chamber, in which a filler works aseptically in a sterile room. Here sprayed peroxide can be dried and removed by one or more stations arranged one behind the other with UV lamps. In this way, a sterile interior of the package to be filled is obtained. Even after the pack has been filled, it remains in the clean room, the filled pack preferably entering the clean room with the closing tools from the filling chamber over a short distance.

After a standstill, for maintenance or for a repair, the unit frame can _. with the closing tools and its drives rotated as a unit into desired positions or be moved. This is also very convenient for spraying the surface of this unit or module with an acid or a base for cleaning.

In a further advantageous embodiment of the invention, the closing tools have sealing jaws which are movable relative to one another, the movement being generated by a hydraulic cylinder which is operated with sterile water as hydraulic fluid and has a piston rod coupled to the sealing jaw. There are hydraulic drives in themselves that are operated with water, but this water is not sterile. By adding chemical agents, which are inexpensive to buy, the usual water (for example from the tap) can be made sterile. For example, there are tablets for sterilizing the water that have silver ions as their active ingredient. These tablets sterilize the tap water in wide aseptic areas, so that the number of germs per unit volume of water for the aseptic packaging of food in packs of the type in question can be easily achieved. The drives with hydraulic cylinders can also be operated perfectly with sterilized water. There are methods for measuring the germ concentration, so that the germ concentration of the water used according to the invention as hydraulic fluid can also be measured and monitored over a longer operating period. Further additions of tablets over time allow the permissible concentration of germs to be maintained. Although leaks cannot be ruled out in hydraulic operation, the drive according to the invention with the hydraulic cylinder actuated by germ-free water can also be arranged in the clean room and thus directly move the sealing jaws back and forth against a counter-jaw, so that the sealing process can take place in the clean room. This means that you do not need a special housing, and the device is easy to maintain and guarantees trouble-free operation. Because the entire device can be kept particularly compact, the clean room can also be kept small.

According to the invention, it is also advantageous if the sealing jaw is designed as an ultrasound sonotrode and the counter jaw as an anvil, the anvil being fixedly attached to the unit frame in the direction of the linear relative movement. This further simplifies the drive and can be made smaller. The movements concentrate on the sealing jaws. It is known to use ultrasonic sonotrodes for sealing. The sonotrode is suitably connected to a converter, and by the drive by means of a hydraulic cylinder which is operated with pure water, and the ^'operation of the sealing apparatus of the invention in the aseptic area is possible according to.

It is advantageous according to the invention if the unit frame is attached to a fixed location in the clean room attached, the main frame overlapping the package conveyor is arranged with the aid of a drive with a hydraulic cylinder. The advantages of the movement options of the closing tools, including their drives, have already been mentioned above. If, according to this further proposal of the invention, a main frame, which should also consist of stainless steel, is arranged in the clean room in such a way that the packing conveyors can be passed under the main frame, then the main frame offers itself as a fastening point for the welding module, and the fastening point can can even be designed to be movable such that the module can be pivoted relative to the main frame. Furthermore, it is particularly advantageous if, according to the invention, the pivoting movement of the unit frame with respect to the main frame is in turn carried out by a hydraulic cylinder, in which in turn germ-free water is used as hydraulic fluid. It can preferably even be the same aseptic water. In other words, the aseptic water used for this hydraulic cylinder can come from the same water cycle and can be treated in the same way as the aseptic water for the drive cylinder of the closing tools. It can be seen again that the device is simplified, easy to clean and can be kept aseptic with simple measures.

By pivoting the unit frame, it is in fact possible to adjust all the components of the closing tools attached to the unit frame in different positions relative to the nozzle jets, with the result that the entire welding module can be brought into contact with cleaning and rinsing liquids intensively and quickly from all sides .

It is advantageous if, according to the invention, the pivot axis of the unit frame is approximately parallel to the direction of the rectilinear relative movement of the sealing tools.This allows the unit frame to be elongated, which extends over the entire sealing unit, from the drive of the sealing jaw to the holder of the outermost, opposite tool part.

If, in a further embodiment of the invention, the swivel angle of the unit frame is between 10 ° and 110 °, preferably between 20 ° and 90 ° and particularly preferably approximately 70 °, then it is possible to refer to all the surfaces and planes on the unit frame with respect to the horizontal ( the entire machine stands on a horizontal floor) so that sprayed, sprayed or rinsed liquids can run off quickly.

It is preferably also ensured that, according to the invention, the components in the clean room surfaces and edges inclined to the horizontal, preferably electropolished, that the floor of the clean room is slightly inclined to the horizontal, the feed lines are preferably housed in stainless steel hoses and / or tubes, and that the pipe connections are placed on the main frame. The surfaces and planes inclined to the horizontal should be inclined in such a way that their surfaces, even if they have stainless steel or are even electropolished, quickly repel any liquid applied during cleaning or the liquid runs off quickly. Different settings of the unit frame at different swivel angles also allow undercut and other surfaces of the components, some of which protrude, to be inclined so that there are no dead spaces for liquids. The surfaces not on the unit frame are mainly the inner walls of the clean room itself, of which the floor is most likely to hold the dripping cleaning liquid. The weak incline of the ground with a slope of, for example, 5 ° to 20 ° and preferably 10 ° with respect to the horizontal also helps here.

When cleaning the components in the clean room, the cylinders and the hoses and pipes connected to them are of course also sprayed. Therefore, according to the invention, stainless steel hoses are used here, which are preferably coated on the inside with Teflon. For this reason, the supply hoses can also come into contact with acids and alkalis. After their action, they are rinsed off with normal tap water and other liquids

Both the modular structure and the pipe connections and other components within the clean room are easy to spray and, if necessary, dry well. This is particularly preferred in that the pipe connections are placed on the main frame and possibly also on the unit frame. On the floor of the clean room and also on the other inner walls of the same there are hardly any connections, hardly any holes or fastening devices, as can otherwise be found in sealing stations on packaging machines.

According to the invention, it is favorable to use the device described above in one or the other of the combinations described for the germ-free sealing of the head, ie the upper part of a blank packaging made of plastic-coated carrier material, for example paper, with the production of a transverse sealing seam. Rectangular or gabled packs, which are widely used for the transport and storage of milk, juices and other liquid foods, have so far not been able to be sealed under aseptic conditions without excessive effort. By using the above device according to the Invention, however, a gable package made from the blank or another packaging made of paper can be closed in a clean room under aseptic conditions by closing the head or the upper part or the partially multilayered top wall of the folded, filled package by cross-sealing. Only then will the contents remain aseptic without bacteria.

With the measures according to the invention, the clean room can be kept particularly sterile by enclosing a small volume. This in turn is made possible by using the described welding jaw drive with the help of the hydraulic cylinder. This is because it has small dimensions and requires little space. A comparable pneumatic cylinder would take up considerably more space. The small welding chamber, the small clean room, results in smaller areas not only of the tools on the unit frame, but also of the side walls, the floor and the top wall of the clean room, so that sterile maintenance is facilitated.

However, the clean room is more or less connected to the atmosphere via the inlet and outlet openings mentioned in the side walls, because the packs have to be transported into and out of the clean room with the aid of the conveyor. For this reason, there is an overpressure of sterile air in the clean room. This is brought into the clean room by generating ultra-filtered, dust-free clean air (as is also used in the chip industry) behind an airlock and blowing it through the inlet openings into the clean room. A deliberately large stream of clean air is blown into the clean room, the partition wall between the aseptic filling room and the clean room preferably being used as a passage. The clean air is allowed to escape through the outlet openings on the one hand and the gaps provided in the housing on the other hand, a slight overpressure being maintained in the clean room. This means that bacteria can no longer be introduced that settle on any surface and contribute to contamination. Nevertheless, after the machine has come to a standstill, the welding chamber designed as a clean room is cleaned in the manner described before a new operation is started.

Further advantages, features and possible applications of the present invention result from the following description of preferred embodiments in conjunction with the attached drawings. Show it: 1 is a perspective view of the underframe of a packing machine, in which essential manufacturing stations of a known type, which have no significance for the invention, have been removed, so that only the clean room which can be seen at the front right as a welding chamber and the upstream filling chamber with four packing conveyors can be seen,

FIG. 2 shows a perspective and enlarged view of the welding and filling chamber, the upstream end of the packing conveyor (FIG. 1) being cut off,

FIG. 3 shows a partially broken side view of the welding and filling chamber when looking in the direction of the partition wall between them.

FIG. 4 shows another enlarged side view with the main frame and the unit frame pivotably arranged on it, looking at the hydraulic cylinder,

5 shows, in perspective, the unit frame pivoted into the operating position in a double design for two pack conveyors, but with the pack conveyors omitted and gable packs shown in the closed position instead,

Figure 6 shows the main frame with two unit frames in the operating position similar to Figure

5, but in a view from the opposite side, where the pipe and hose connections are located,

FIG. 7 shows a simplified representation of the unit frame pivoted in relation to the main frame in the cleaning position by omitting the packs and a drive,

Figure 8 is a perspective view of the main frame with two unit frames similar to Figure 5, but without packs and in the non-operational position of Figures 7 and

Figure 9 shows the view of the device of Figure 8 from the other side, where the pipe and hose connections are attached.

To seal the head 1 of a plastic packaging-made plastic packaging 2 under sterile conditions by producing a transverse sealing seam 3, the welding module, generally designated 4, and the conveyor 5 are used to transport the upright packaging 2. Four pack conveyors 5 arranged parallel to one another can be seen in FIGS. 1 and 2. For the explanation of the device in the embodiment shown here, however, the description of a single conveyor 5, which extends in the longitudinal direction of the overall machine, which also coincides with the transport direction 6 of the conveyor 5, is sufficient. The support feet 7 rest empty in FIG. 1 shown base stand 8 of the entire machine, in which the machine drives are to be arranged. For example, a main shaft, gear, cam 9, etc. The base stand 8 is closed at the top by a table top 10 that is inclined at 10 ° to the horizontal. This extends under the pack conveyors 5 through the filling chamber 11 into the clean room 12, the floor 13 of which it forms. To better illustrate the position of the floor 13, base plates 13a are shown in some figures (FIGS. 4-7 and 9) encapsulated in a housing 14 , drives 15 reach through these base plates 13a. These drives 15 could be used for the pack conveyor 5 or for other purposes.

The clean room 12 is enclosed by side walls, of which only the two side walls 16 and 17 arranged opposite one another in the transport direction 6 are shown. The top wall 18 is formed by the underside of a flow box 19 for clean air, which is connected upstream to an air lock 20, which is shown only schematically in FIG. 1 as an empty box

Ultra-filtered, dust-free clean air first flows through the box 12 into the filling chamber 11 and then passes through inlet openings 21 from the filling chamber 11 into the clean room 12. A larger inlet opening 21 can be seen in the special embodiment in FIG. and movable sliding plate 22 is formed. However, additional entry openings, not shown in FIG. 2, can also be provided under this sliding plate 22.

The respective package conveyor 5 enters the clean room 12 through the inlet opening 21 and can leave it through the respective outlet opening 23 on the opposite side wall 17.

Cleaning devices in the form of nozzles 24 are shown both in the filling chamber 11 and in the clean room 12. The piping system for the supply of cleaning liquid to the nozzles 24 is not described in detail here.

The weld module, generally designated 4, has a unit frame 25 which carries three reinforcing ribs 26 against deflections and, for better insertion of the packing head 1, in particular in the area of the transverse sealing seam 3, insertion plates 27. The most important thing on the unit frame 25, however, are the closing tools attached, which can be seen quite well in FIG. 8 in the form of the ultrasonic sonotrode 28 as sealing jaws and anvil 29 as counter jaws fixed in the direction of movement 30 of the sonotrode 28. You can also see the one with the sonotrode there 28 and converter 31 necessary for their operation. A cable and cooling water lines run in the hose 32 for its supply.

A hydraulic cylinder 33, which is operated with aseptic water as hydraulic fluid, is used as the drive for the movement of the sealing jaw configured as ultrasonic sonotrode 28 in the direction of movement 30 and back. The pipe connections 34 are shown, but not the individual lines to hydraulic cylinders starting from there.

Each unit frame 25 can be pivoted upwards about a horizontally arranged pivot axis 35 over a pivot angle of approximately 70 ° with respect to the horizontal.

A main frame 36 overlaps the four lines of the package conveyors 5 running parallel to one another and is firmly anchored to the base frame 8. On this machine-fixed main frame 36 there is a locking block 37 which is clearly visible in FIG. 5 and which has recesses which extend inwards and are not shown and into which invisible pins of rotary supports 38 fastened to the unit frame 25 protrude. The pins lie in the pivot axis 35 and allow and guide the pivoting movement of the unit frame 25.

The drive of the unit frame 25 is shown as a lifting cylinder 39 with a piston rod 40. At the free end of the piston rod 40 there is a drive swivel 41, with the aid of which the force originating from the water hydraulics is transmitted to the unit frame 25 for pivoting. The supply hoses connected at 42 with Teflon encasing for the supply of sterile water as hydraulic fluid to the hydraulic cylinders 39 are not shown

In operation, the unit frame 25 is pivoted into the position shown in FIGS. 1 and 4-6, and the direction of travel of the packs 2 is also the transport direction 6 of the individual lines of the pack conveyors 5. The packs are guided intermittently under the respective closing tools 28-31 , closed and leave the clean room 12 through the outlet openings 23.

For cleaning, the hydraulic cylinders 39 are actuated for driving and pivoting the unit frame 25, which is pivoted up into the position shown in FIGS. 2 and 7-9. Then sprayed over the nozzles 24 and cleaned. The liquids can run off the surfaces, either from the swiveled-up position, for example in FIG. 7, or from the swung-down position, for example in FIG. Bezuαszeichenlistθ

1 head

2 plastic packaging

3 cross seal seam

4 welding module

5 sponsors

6 Direction of transport

7 support feet

8 base stand

9 cam

10 table top

11 filling chamber

12 clean room

13 floor

13a base plates

14 housing

15 drives

16 side wall

17 side wall

18 overcame

19 flow box

20 airlock

21 inlet opening

22 sliding plate

23 outlet opening

24 cleaning nozzles

25 unit frames

26 reinforcing ribs

27 insertion plates

28 ultrasonic sonotrode

29 anvil

30 direction of movement of the sonotrode

31 converters

32 hose

33 hydraulic cylinders

34 pipe connections

35 swivel axis

36 main frame

37 locking block

38 swivel supports

39 lifting cylinders

40 piston rod

41 drive swivel

42 Connection of the supply hoses

Claims

Patent claims

1. Device for closing a sterile-filled plasticizer (2) under aseptic conditions in a clean room (12) with side walls (16, 17), bottom (13, 13a) and top wall (18), in which a conveyor (5) for Transport of the upright package (2) crosses the clean room (12) with the help of an inlet opening (21) and an outlet opening (23) in opposite side walls (16, 17), with cleaning devices (24) and with closing tools (28 - 31), thereby characterized in that the closing tools (28 - 31) are fastened with their drives (33) to a unit frame (25) and are accommodated with this in the clean room (12), and that the surfaces (13, 16 - 18) of the clean room ( 12) Made of stainless steel.

2. Apparatus according to claim 1, characterized in that a drive shaft, cam (9) and gear under the sod (13, 13a) of the clean room (12) are arranged and drives (15) for the package conveyor (5) the bottom (13 , 13a) pass through in a housing (14).

3. Apparatus according to claim 1 or 2, characterized in that the cleaning devices have nozzles (24) for the supply of acids, alkalis, water and other liquids.

4. Device according to one of claims 1 to 3, characterized in that the closing tools (28 - 31) relatively movable sealing jaws (28), the movement being generated by a hydraulic cylinder (33) which is operated with aseptic water as hydraulic fluid and has a piston rod coupled to the sealing jaw (28).

5. Device according to one of claims 1 to 4, characterized in that the sealing jaws are designed as an ultrasonic sonotrode (28) and the counter jaws as an anvil (29), the anvil in the direction (30) of the rectilinear relative movement stationary on the unit frame (25 ) is attached

6. Device according to one of claims 1 to 5, characterized in that the unit frame (25) attached to a stationary in the clean room (12), the package conveyor (5) overlapping main frame (36) by means of a drive with hydraulic cylinder (39) pivotable is arranged

7. Device according to one of claims 1 to 6, characterized in that the pivot axis (35) of the unit frame (25) is approximately parallel to the direction of the linear relative movement of the sealing tools (28 - 31)

8. Device according to one of claims 1 to 7, characterized in that the pivoting angle of the unit frame (25) is between 10 ° and 110 °, preferably between 20 ° and 90 ° and particularly preferably at about 70 °.

9. Device according to one of claims 1 to 8, characterized in that the components (4, 25, 5, 14) in the clean room (12) inclined to the horizontal, electropolished surfaces, the bottom (13, 13a) of the clean room (12) is slightly inclined to the horizontal that the feed lines (32) are preferably housed in stainless steel hoses (32) and that the pipe connections (34) are placed on the main frame (36).

10. Use of the device according to one of claims 1 to 9 for the aseptic sealing of the head (1) of a blank packaging (2) made of plastic-coated carrier material, for example paper, with the production of a transverse sealing seam (3).