US3884012A

US3884012A - Method and apparatus for the packing under aseptic conditions of sterile goods into containers

Info

Publication number: US3884012A
Application number: US380573A
Authority: US
Inventors: Georg E Ernstsson; Kjell H Martensson
Original assignee: Tetra Pak Developpement SA
Current assignee: Tetra Pak AB
Priority date: 1972-08-11
Filing date: 1973-07-19
Publication date: 1975-05-20
Anticipated expiration: 1992-05-20
Also published as: AU5820073A; DE2339498A1; FR2195550A1; IT995094B; JPS4944883A; GB1394917A; CH567964A5; FR2195550B1; SE423808B; CA1000603A

Abstract

A method and apparatus for packing sterile goods into containers under aseptic conditions wherein a thermoformable web is introduced into one end of a processing tunnel within which sterile conditions are maintained. As the web passes through the tunnel it is drawn into a series of end-to-end connected open-top containers. A second web is applied to the first web along the corresponding opposite longitudinal edge portions to form a tube which is then filled with the material to be packaged so that the material fills the drawn container spaces. The two webs are then further joined together by sealing along zones closed in themselves around the container openings so that each container becomes closed. After the two webs pass out of the opposite end of the tunnel, the filled containers are then separated from one another by severing.

Description

Ernstsson et al.

[ METHOD AND APPARATUS FOR THE PACKING UNDER ASEPTIC CONDITIONS OF STERILE GOODS INTO CONTAINERS [75] Inventors: Georg E. Ernstsson, Staffanstorp;

Kjell H. Martensson, Malmo, both of Sweden [73] Assignee: Tetra Pak Developpement SA, Lund,

Switzerland [22] Filed: July 19, I973 [21} Appl. No.: 380,573

[30] Foreign Application Priority Data Aug 11, 1972 Sweden 10419/72 [52] US. Cl 53/22 A; 53/28; 53/30; 53/112 A; 53/167; 53/180; 53/184 [51] Int. Cl B65b 9/04; B65b 55/06 [58] Field of Search 53/28, 30, 22 A, 112 A, 53/180, 180 M, 182, 182 M; 21/2, 78

[56] References Cited UNITED STATES PATENTS 3,383,831 5/1968 Goldsmith et al. 53/180 M 3,513,627 5/1970 Doucette et al 53/180 M [4 1 May 20, 1975 Bergstrom 53/167 Egger 53/167 X [57] ABSTRACT A method and apparatus for packing sterile goods into containers under aseptic conditions wherein a thermoformable web is introduced into one end of a processing tunnel within which sterile conditions are maintained. As the web passes through the tunnel it is drawn into a series of end-to-end connected open-top containers. A second web is applied to the first web along the corresponding opposite longitudinal edge portions to form a tube which is then filled with the material to be packaged so that the material fills the drawn container spaces. The two webs are then further joined together by sealing along zones closed in themselves around the container openings so that each container becomes closed. After the two webs pass out of the opposite end of the tunnel, the filled containers are then separated from one another by severmg.

8 Claims, 6 Drawing Figures METHOD AND APPARATUS FOR THE PACKING UNDER ASEPTIC CONDITIONS OF STERILE GOODS INTO CONTAINERS The present invention relates to a method for the packing under aseptic conditions of sterile goods into containers, consisting in that a thermoformable material web, after it has been subjected to a sterilizing medium or during a simultaneous sterilization, is heated to a temperature required for thermoforming processing, whereupon the web or a selected part thereof is subjected to a thermoforming processing with the purpose of moulding containers from the web, that a second material web is joined to the said first thermoformable material web, preferably along its web edges to form a tube, the sterile material to be filled being supplied to the tube and the tube being pressed fiat, with division at the same time of the columns of material present in the tube, in such 'a manner that the material surfaces in the said material webs can be sealed together or joined to one another in some other manner at least along the zones, closed in themselves, around the container openings with the object of enclosing the sterile material in the containers.

In the technique of packaging, and especially in packing processes for the type of goods which normally have limited keeping properties, attention is directed more and more towards an improvement of packing systems existing already or towards the producing of some which would make possible prolonged keeping of the goods packed. By the use of these packing systems it is intended first and foremost that the goods should allow normal distribution and storage of the products until their consumption. Demands will therefore be made not only on the moulding and special treatment of the goods themselves with regard to their keeping properties, but also on the manner in which they are packed, and likewise on the packing containers and their material composition. Dairy products, for example, constitute such goods referred to here, and packing systems have also been developed for the aseptic packaging of such products in consumer packages.

In one of the known rational methods for the packing of sterile materials under aseptic conditions to make possible prolonged keeping of the material packed, a combination material web is used which comprises a fibrous base layer with a plastic layer and a metal foil layer placed on top of it. The web is reshaped to a tube, to which is supplied the sterile material to be filled, and which is then divided under aseptic conditions to wholly filled and closed packing units. In another packing system a web of plastic material is used, from which containers are formed by means of vacuum drawing, with at least the filling and closing operations being carried out in an aseptic atmosphere.

By the very fact of new plastic materials or combinations of plastic materials being produced, which show an improved resistance to penetration by gas and water vapor, possibilities exist now of manufacturing sterile packages consisting of solely plastic material or plastic material in combination with a lid or closure part consisting of another material, for example a metal foil or consisting of a material combination. Modifications or improvements on such already existing methods of packaging have been suggested where a plastic material is used for the moulding of the packing container. In these methods, container bodies are frequently moulded by vacuum drawing from a plastic material heated previously, whereupon the containers are filled with the sterile material intended for the packaging and closed in that, for example, wafers are made to cover the openings of the filled containers, which wafers are sealed to the opening edge of the container or to the area close by. To achieve a sterile milieu in the packing of sterile materials, certain parts of the device, such as filling or closing elements, have been built into or enclosed by a chamber in which a substantially sterile milieu was maintained.

In these packing machines certain problems were experienced, however, with maintaining the sterility in the so-called sterile chamber, which has its reason in that existing machines and systems have not been adapted fully according to the new conditions.

By the present invention, however, a method is suggested which presents a principle that has proved a ra tional packaging procedure for a sterile filling material. This principle, in accordance with the invention has been adapted for application to the new packing materials, allowing the aseptic conditions to be reliably maintained during the packing process at the same time as the advantages of the new material can be taken advantage of. The invention is characterized in that both the said first thermoformable material web and the said second material web are introduced into a tunnel and are guided through the same in such a manner that the material webs, together with the walls of the tunnel, form a chamber, in which a sterile atmosphere is maintained, the thermoforming processing of the first material web and the joining together of the two material webs along their web edges to form a tube being carried out in the said chamber, whereafter the tube is guided out of the tunnel and the sterile material supplied to the tube is divided and encapsulated in the formed containers, which finally are separated from one another by means of a cut through both the said webs.

In the following the invention will be described with reference to the enclosed schematic drawings, in which FIGS. 1, 3 and 5 show in side view and partial section different variants of a system for the carrying out of the method in accordance with the invention, and

FIGS. 2, 4 and 6 show in cross-section a packing tube in accordance with FIGS. 1, 3 and 5 respectively.

In FIGS. 1, 3 and 5 reference designation 1 relates to a tunnel and 2 to a thermoformable material web which is intended to be introduced into the one end of the tunnel and to be moved out from its other end together with a second material web 3, which is applied to the first thermoformable material web in the tunnel. The walls of the tunnel 1 form, together with the web 2 and the joined first and

second webs

2 and 3, sterile chamber 4. The sterile chamber can be provided at its front end with a pre-treatment chamber 5, which may consist of an extended part of the tunnel 1, this chamber being formed similar to the sterile chamber 4, that is to say that the walls of the tunnel together with the web 2 form the chamber. A pre-treatment chamber 6 is arranged for the introduction of the said material web 3. This chamber is realized preferably as a superstructure on the sterile tunnel l and communicates with the same via an opening 36 in the tunnel wall.

Underneath the sterile chamber 4 a forming tool 19 is arranged for the forming of container bodies 21 by means of thermoforming processing of the material web 2. The forming tool may consist of a forming box which comprises at least one, but preferably several forming cavities and which is adapted for example for vacuum drawing of the material web 2. Moreover, the forming box is adapted so that it can follow the web some distance in the direction of movement of the same during the forming operation itself, thereafter rapidly to revert to the original position for the processing of a nonprocessed part of the web. Instead of a forming box the forming tool may consist of a number of forming bodies which are designed for the same purpose as the said forming box, the forming bodies being arranged so that they run on an endless chain underneath the material web 2. In the case of such an arrangement the containers formed in the forming bodies can be allowed to remain in the forming cavity of the forming bodies for an appreciably longer time than what is possible otherwise for known rational forming processes. In the course of this the container bodies can cool down in the forming cavity without special cooling having to be applied and also better conditions for a prevention of a shrinkage of the material being obtained. Furthermore, in this manner the thermoformable material web 2 is given a necessary push up during the transport through the sterile chamber 4 as well as a support at the different working operations.

On the side opposite the thermoformable material web 2, that is to say in the sterile chamber 4, a tool 20 may be arranged for a positive forming effect on the material web 2, see FIG. 1. In the sterile chamber 4 is arranged a filler 22 to fill the container bodies 21 with sterile goods. Furthermore, a sealing device 23 is provided in the chamber 4, which for example by means of heat and pressure and by means of compression plates 24 seals the said second web 3 to the material web 2, so that the sterile goods filled into the containers 21 becomes enclosed. In the upper part of the tunnel l is an intake 18 for sterile air, which air is introduced into the sterile chamber 4 and is contained in the same, preferably under a certain pressure.

Before the thermoformable material web 2 is subjected to a thermoforming processing by means of the forming tools 19, 20, the material web has to be heated up to a temperature necessary for the thermoforming processing, that is to say to a suitable degree of softening. This heating operation is carried out appropriately outside the sterile chamber 4, because the sterile atmosphere contained in the chamber may become mixed with medium evaporating off the web. In FIG. 1 the heating elements are indicated by reference numeral 12, which are arranged outside the sterile chamber 4.

These. heating elements may consist for example of heating spirals designed for electric heating. The heating operation may be carried out, as shown in the figure, in a chamber, which in turn may consist of the said pre-treatment chamber. The upper part of the pretreatment chamber 5 may be provided with an element 17 for extracting by suction the atmosphere contained in the chamber. Furthermore, the pre-treatment chamber may be provided instead or at the same time with different elements for the washing and/or sterilization of the material web 2.

The said pre-treatment chambers 5 and 6 are intended foremost to contain elements for the cleaning of the two

respective material webs

2, 3 by means of washing and/or sterilizing before they are introduced into the sterile chamber 4. The element 11 may be adapted so as to irradiate the webs with ultraviolet light,the element 4 for electron spraying of the webs or bath and spray devices containing hydrogen peroxide, alcohol or some other sterilizing, washing or disinfecting fluid which is kept in the bath or which is applied to the webs in the form of finely divided particles. 5 Traces of such liquid medium can be removed from the webs by evaporation, suitable heating elements for the purpose being arranged in chambers 5, 6. By means of these heating elements or by means of the said elements 12 provided for the heating of the material web I 2 to the required thermoforming processing temperature, the web can be subjected to a thermal sterilization. In both the pre-treatment chambers 5 and 6 sterile atmospheres are of course being maintained for this purpose and suitable delimitations exist against the atmosphere surrounding the chamber.

For the introduction of the two

material webs

2 and 3 into the sterile tunnel 1 or the pre-treatment chambers 5, 6 and for the passing out from the sterile tunnel of the combined first and

second webs

2 and 3, the

elements

15, and 15" are provided at the entrance l3, 13, 36, 36' and at the exit 37 respectively, which prevent the surrounding atmosphere from penetrating into the tunnel 1 and/or the chambers 5 and 6. These elements may consist of a sluice comprising a suitable sterilizing or disinfecting fluid, an air curtain consisting of a sterile air stream, a liquid curtain consisting of finely divided particles of hydrogen peroxide, alcohol or a washing or disinfecting, non-corrosive liquid, a sleeve element or any other means which prevents the surrounding atmosphere from penetrating into the tunnel and/or the chambers.

The pre-treatment chambers 5 and 6 respectively must be separated from the sterile chamber, which can be done in the simplest form by a screen wall 14 and respectively, the pressure of sterile air prevailing in the sterile chamber 4 being made to flow out to the pretreatment chambers through the

openings

13 and 36 respectively which are arranged between the screen walls and the

material webs

2 and 3 respectively. The pre-treatment chambers can also'be separated from the sterile chamber by means of a sluice, a liquid or air curtain or any other suitable arrangement.

The washing and/or sterilization process must be carried out outside the sterile chamber 4. If liquid or gaseous washing and/or sterilization agents are used, the said processes must likewise be carried out outside the pre-treatment chambers 5, 6, since the agents, if used in the pre-treatment chambers, may be blended into the atmosphere contained in the chambers and there is an obvious danger, in spite of the presence of sluices or similar arrangements between the pre-treatment chambers and the sterile chamber, that the atmosphere mixed with washing and/or sterilization agents may penetrate into the sterile chamber 4 or that such agents may precipitate in liquid form (condensation) on the material web .to accompany the same into the sterile chamber.

As can be seen in FIGS. 1, 3 and 5 vats 8 and 28 are respectively. These vats are intended to contain a washarranged outside the pre-treatment chambers 5 and 6 so that the residues of the treatment fluids evaporate. For the removal of the surplus fluid it is also possible for example to use an air knife, such as that indicated in FIG. 1 by numeral 30, with the surplus liquid flowing or dripping back into the vat 28.

Outside the exit of the sterile chamber 4 is arranged a knife or shear element 38, which is intended to separate the filled and sealed containers from one another by means of a cut through the two

material webs

2 and 3. Possible surplus material from the said second material web 3 may be rolled up on a roller 39. An endless belt 40 or another suitable transport device is arranged for taking over the separated packing containers 41.

The filling tube 22 extends to just above the sealing

elements

23, 24 and the filling level 42 is situated higher than the closing zone.

For the joining together of the two

material webs

2, 3 along their longitudinal edge portions for the formation ofa tube, the longitudinal

joint elements

43, 44 are provided which for example, by means of heat and pressure seal the webs to one another. As shown in FIGS. 2, 4 and 6 two longitudinal joints 45 are obtained in this manner on the tube.

In accordance with the embodiment shown in FIG. 3 the moulding tool 19 is shown with a number of moulded bodies 52 which are fixed on a chain 47 moving over

wheels

48, 49. For eventual forming and treatment of the second material web 3 forming tools 20 can be arranged on a second endless chain 50 arranged opposite to the first endless chain 47 and with the

united material webs

2, 3 passing between the chains.

In FIG. 6 is shown that the thermoformable material web 2 has been joined accurately to the moulding cavity 52 of the moulding element 19. In the base of the moulding cavity 52 is shown that a part of the wall portion of the packing container has been pushed in so as to form an indentation 51. On the sidewalls of the packing containers is exerted an internal pressure directed inwards so that the packing container is made to delimit an internal packing volume which is smaller than the maximum volumetric capacity of the packing container. This indentation of the packing wall is carried out before the closing of the container and the indented wall is put into this position until the packing container is closed.

The thermoformable material web 2 may consist of a polyvinylidene chloride-coated polyvinylchloride web, a polyvinylidene chloride-coated polystyrenb web, a co-extruded web consisting of a polyethylenepolyvinylidene chloride-polyethylene combina-" tion, an acrylonitrile copolymer built up of polystyrenepolyvinylidene chloride-polyethylene. Other combinations y of course also be used in the building up f process itself is started, the sterile chamber 4 and the be set up, which is done in that the two

material webs

2, 3 are introduced into the tunnel 1. Subsequently the sterile chamber and the pretreatment chambers 5, 6, if any, have to be sterilized and/or disinfected, which implies that the elements situated in the sterile chamber, such as the forming elements 20, the fillers 22 and so on become washed and sterilized.

In the' course of the packing, as can be seen from FIG. 1, the thermoformable material web 2 is passed from a roller 7 and down into a vat 8 containing a washing and/or sterilizing liquid 9 for the purpose of cleaning or washing and sterilizing the material web 2. After the vat 8 the surplus liquid is absorbed or removed in some other manner from the web 2 by means of the element 10 designed for this purpose. Usually this is followed by a heating of the web by means of the heating element 16 shown, so that any residues of the treatment liquids evaporate. After these operations the thermoformable material web 2 would be ready to be introduced into the sterile chamber. As mentioned earlier, however, the web has to be heated to the required thermoforming processing temperature before it is introduced into the sterile chamber. In this case the heating elements intended for this are arranged in the vicinity of the inlet opening 13 of the sterile chamber, so that the web is strongly heated when it is introduced into the chamber, the heating operation acting as a disinfecting sluice for the entrance of the web into the sterile chamber. The said special heating element 16 for the drying of the web would then probably be omitted.

In accordance with the embodiment shown in the figure, however, the thermoformable material web 2 is introduced into the sterile tunnel 1 after cleaning and drying operations. The web is introduced into the sterile tunnel in a preferably vertical or horizontal plane, or at least at right angle to the end wall of the tunnel and in a substantially even layer. At this entrance into the tunnel the web is passed through or via a sluice or some other element which is arranged so as to delimit the sterile chamber against the surrounding atmosphere. If the material web is introduced, as mentioned, in an even layer and substantially at right angle to the end wall of the tunnel, the element delimiting against the environment may consist simply of a curtain directed at right angle to the web and consisting of sterile air. The curtain Will then form an extension of the end wall of the sterile tunnel 1.

The front part of the sterile chamber 4 is realized according to the embodiment shown as a pre-treatment chamber 5, where the web 2 can be subjected to a sterilizing and/or disinfecting effect by means of different elements or agents. This pre-treatment chamber 5 may also be arranged for the heating of the material web 2 to the necessary thermoforming processing temperature, the material web 2 being subjected in this same "hf'heati ng process to a thermal sterilization. The material web'2 thus passes after entrance into the sterile tunnel pretreatment chambers 5 and 6, if such are used, must-:1

31,1 an element 11 which may be provided for subjecting "the purpose of disinfecting and/or sterilizing the web the web to electron spraying and/or ultraviolet light for before being introduced into the sterile chamber 4.

Furthermore, the material web 2, before being introduced into the sterile chamber, passes the heating elefrrient 12,'where the web is heated up to the tempera- "turei'required for thermoforming processing.

'When the material web has a degree of softening suitable for the thermoforming processing, it is introduced into the sterile chamber itself. The sterile chamber 4 is delimited against the pre-treatment chamber 5 in such a manner that the atmosphere maintained in the pretreatment chamber should not be able to penetrate into the sterile chamber. By keeping the atmosphere maintained in the sterile chamber 4 under pressure, the delimitation between the chamber may consist simply of a single screen wall 14 or the like, as shown in the figures, the material web being introduced into the sterile chamber through the inlet opening 13.

The material web 2 thus heated to softening is subjected subsequently to the thermoforming processing by means of the forming elements 19 and/or 20 with the object of forming container bodies 21, which in a later stage are filled with the sterile goods intended for packaging by means of the fillers 22 shown. After the containers have been filled they must be sealed, which is done by applying the said second material web 3 to the thermoformable material web 2 so that it is preferably wholly covered.

As can be seen from FIGS. 1, 3 and 5 the said second material web 3 is passed down from a roller 27 into a vat 28 which contains a cleaning, washing and/or sterilizing liquid similarly to the set-up for the treatment of the first thermoformable material web 2. After the web 3 has passed the vat 28, the surplus fluid is drawn off the web by means of the air knife 30 shown or by an absorbing element 31. Subsequently the web passes a heating element 32, whereby any residual traces of the treatment fluids are evaporated. The material web 3 is then introduced into the pre-treatment chamber 6 through its opening 36'. In the opening the web passes the element 15" which is intended to form a sluice or a curtain, so that the atmosphere surrounding the chamber cannot penetrate into the chamber. If the material web is introduced into the pre-treatment chamber in e.g., a substantially horizontal or vertical position and the web presents substantially even surfaces, the said element may be designed for the production of a vertical or horizontal sterile air curtain or air seal, which fills out the interspace between the walls of the chamber and the surface of the material web. In the pre-treatment chamber 6 the material web 3 passes further various elements 34 for the disinfection and/or sterilization of the web, whereby it is possible, as mentioned earlier, for the elements to be arranged so as to subject the web to electron spraying and/or ultraviolet light. Subsequently, the material web 3 is introduced into the sterile chamber 4 to be joined to the first thermoformable material web 2. The web 3 passes through an opening 36 in the wall of the sterile tunnel 1. This pre-treatment chamber 6, similar to the other pretreatment chamber 5, is separated from the sterile chamber 4 by means of a screen wall or the like.

The said second material web 3 is introduced and joined to the first material web 2 along the longitudinal edge parts of the web so as to form a tube. After the tube has been filled with material the two webs are joined together by sealing to one another at least along zones closed in themselves around the container openings. The sealing or closing is carried out for example by means of heat and pressure with the

tools

23, 24 shown in FIGS. 1, 3 and 5.

On leaving the sterile tunnel l, the combined first and

second material webs

2, 3 pass a curtain 15', a sluice or some other element which screens the opening or mouth 37 or the tunnel in such a manner, that the atmosphere existing outside the sterile chamber 4 cannot penetrate through the said opening. Since the thermoformable material web 2 has been given an even upper side through the application of the second material web 3 and in this case the combined first and

second material webs

2, 3 are passed e.g., substantially horizontally or vertically out of the tunnel 1, the said curtain or sluice element 15 may consist of a device for the generation of a laminar, vertically respectively horizontally directed sterile air stream which in the form of a curtain fills the space between the end wall of the tunnel l and the upper side of the combined webs.

After the formed, filled and sealed containers 21 have been passed out from the tunnel 1, they are separated from one another by means of knives or some other suitable element 38 in that the two said

webs

2, 3 are cut through or severed between the container bodies formed, so that separate container units 41 are obtained. Any surplus of the said second and covering material web 3 can be rolled up on a roller 39. The separated containers 41 are removed lastly on a conveyor 40 for further treatment, for example for packing in transport containers, or the like.

Without exceeding the scope of the concept of the invention, modifications may be made to the process described. Thus it is quite possible to introduce into the sterile chamber 4 a gas actively sterilizing in itself instead of the said sterilizing air with the object of sterilizing or disinfecting the chamber and to maintain a sterile atmosphere in the same. In the packaging processes for foodstuffs sterilizing air is to be preferred, however.

Furthermore, the

openings

13 and 36 between the sterile chamber 4 and the pre-treatment chambers 5 and 6 respectively, if any, may have special elements for the delimiting of the chambers from one another. Such elements may consist of a liquid seal filled with a suitable liquid, an air curtain consisting of a laminar, sterile air stream, a liquid curtain consisting of for example finely divided hydrogen peroxide or alcohol particles a sleeve element or some other means for preventing the atmosphere prevailing in the pre-treatment chambers from penetrating into the sterile chamber 4. The elements or agents mentioned here are specially applicable for the purpose of screening the sterile chamber 4 and the pre-treatment chambers 5, 6 in the limit zones of the same towards, or the inlet and outlet openings to, the atmosphere surrounding the chambers.

The said pre-treatment chambers 5, 6 may of course take the most suitable shape and they may thus be quite different from the design referred to in the description and shown in the figures. Thus they need not, as is the case in the pre-treatment chambers 5 shown in the figures, consist of partly a tunnel, partly a material web which in fact is intended for further processing to container bodies. It would also be possible, if this were found appropriate, and as pointed out earlier, wholly to eliminate the pre-treatment chambers 5, 6. The heating element 12 provided outside the sterile chamber 4 for the heating of the thermoformable material web 2 constitutes an advantageous treatment so that'the material web should be able to be introduced directly into the sterile chamber. It is also conceivable, however, to allow the second material web 3 to pass a heated zone before or during its introduction into the sterile chamher 4, which means that in certain cases the pretreatment chamber 6 could be discarded.

The material or combination of materials in the first and

second material webs

2, 3 applied can of course be different from the ones suggested earlier. As a sole example may be mentioned that the said second and closing material web 3 may consist of simply a metal foil, for example an aluminium foil, which is coated possibly with for example a thermally active, adhesion promoting agent.

lt must be emphasized, that it is essential, that the thermoformable material web 2, the said second material web 3 and/or the combined

material webs

2, 3 are passed into and out of the sterile unit as limits to the surrounding atmosphere with a surface or upper side which is even, and that the web or webs are conveyed in an either substantially horizontal or vertical plane, or at least at right angle to the end wall of the tunnel. Furthermore, it is essential that the said first material web 2 and/or the combined first and

second material webs

2, 3 together with the sterile tunnel 1 form the said sterile chamber 4, that is to say that the material web and the combined

webs

2, 3 constitute a wall in the sterile chamber.

The configuration of the set-up shown in the figures on the outside of the said chamber 4, 5 and 6 is thus of less importance. For the sake of completeness it should be mentioned however, that the

material webs

2 and 3 each by itself and in combined form are supported, guided etc by means of guide rails, rolls or other

suitable elements

46, 47, 48, 49, which in a satisfactory manner can bring the webs or the combined webs in the right position or positions during the various courses from the rolling off from the respective supply rollers 7, 27 and until the filled, sealed and separated containers 41 have been obtained. The invention is not limited therefore to the embodiment shown, but only by the following patent claims.

We claim:

1. A method of forming, filling and sealing containers from a first and a second web of substantially impermeable thermoformable material of indeterminate length while under aseptic conditions comprising moving the webs in the direction of their length with one surface facing a sterile chamber, said webs constituting walls of the sterile chamber, forming a plurality of container elements in at least one of said webs, sealing the two webs together along their longitudinal side edges to form a tube, introducing a filling material into the tube to fill the container elements formed in said at least one of said webs, sealing the webs together about the edges of the container elements to close and seal the separate containers, the steps of forming the container elements, sealing the longitudinal edges of said webs to form the tube, and filling the tube with filling material being carried out while the webs constitute walls of the sterile chamber, and finally separating said filled and sealed containers into separate containers after leaving the sterile chamber.

2. A method as claimed in claim 1 wherein container elements are formed in both webs, opposing pairs of said elements being sealed together to form single containers.

3. A method as claimed in claim 1 and further comprising sterilizing said webs before said webs form walls of the sterile chamber.

4. A method as claimed in claim 1 and further comprising heating said at least one web to thermoforming temperatures before said webs form walls of the sterile chamber.

5. A method as claimed in claim 4 wherein the temperature of the heating step is sufficient to sterilize said at least one web.

6. A method as claimed in claim 1 wherein a sterile gas is passed into said sterile chamber under a pressure exceeding that of the surrounding air so as to prevent surrounding air from entering said sterile chamber.

7. A method as claimed in claim 1 wherein the step of forming container elements in at least one web is carried out while moving the at least one web constituting a wall of the sterile chamber.

8. Apparatus for forming and filling containers with a filling material under aseptic conditions from a first and a second web of thermoformable material of indeterminate length comprising a tunnel member having at least one open side, means for continuously passing each of said webs along the at least one open side of said tunnel member to form therewith a closed sterile chamber, means for introducing a sterile gas into said sterile chamber under a pressure exceeding that of the surrounding air to prevent surrounding air from entering said sterile chamber, means in said sterile chamber for forming container elements in at least one of said Webs, means in said sterile chamber for sealing together the longitudinal side edges of said webs to form a tube, means in said sterile chamber for introducing a filling material into the tube to'fill the container elements, means outside of said sterile chamber for-sealing said filled tube into separate containers and means for separating said tube into separate containers.

Claims

8. Apparatus for forming and filling containers with a filling material under aseptic conditions from a first and a second web of thermoformable material of indeterminate length comprising a tunnel member having at least one open side, means for continuously passing each of said webs along the at least one open side of said tunnel member to form therewith a closed sterile chamber, means for introducing a sterile gas into said sterile chamber under a pressure exceeding that of the surrounding air to prevent surrounding air from entering said sterile chamber, means in said sterile chamber for forming container elements in at least one of said webs, means in said sterile chamber for sealing together the longitudinal side edges of said webs to form a tube, means in said sterile chamber for introducing a filling material into the tube to fill the container elements, means outside of said sterile chamber for sealing said filled tube into separate containers and means for separating said tube into separate containers.