Abstract:
A method for filling containers with a filling material and subsequently sealing the filled containers with container closures includes, using a linear transporter, moving the containers in a container-transport direction and in a timed manner, toward a sealing device, at the sealing device, sealing the containers with a container closure during a stationary phase of a timed movement, moving the containers onward in a subsequent movement phase of the timed movement, and during the subsequent movement phase, and before applying a container closure on the containers, dosing headspaces of the containers with liquid nitrogen to force air out of the headspace and to achieve an internal pressure in the sealed containers.

Description:
RELATED APPLICATIONS 
       [0001]    This application is the national stage entry under 35 USC 371 of PCT application PCT/EP2012/002348, filed on Jun. 2, 2012, which claims the benefit of the Jul. 5, 2011 priority date of German application DE 10 2011 106 760.8, the contents of which are herein incorporated by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The invention concerns a method and apparatus for filling containers. 
       BACKGROUND 
       [0003]    The dosed introduction of liquid nitrogen in the headspace of filled containers is known in particular in the drinks industry, in order on the one hand to force air and thus oxygen out of the headspace by the evaporation or degassing of the nitrogen (oxygen reduction), but on the other hand to generate an internal pressure in the sealed container, so that in this way an adequate stability is achieved even for thin-walled containers, i.e. low-weight containers, and thus the use of containers of this kind is possible. In particular, in the case of oxygen-sensitive products or filling materials, their shelf-life and quality is substantially improved due to the oxygen reduction in the headspace of the containers, e.g. the vitamin C decomposition in relevant drinks is reduced. 
         [0004]    Also known is the sterile filling and sealing of containers, in particular, the sterilization of the closures used for sealing by charging with a suitable sterilization medium, for example with aqueous hydrogen peroxide (H 2 O 2 ) at a high concentration and by subsequent drying immediately before the use of the particular container closure (EP 1 741 666 A2, EP 0 993 418 B1, EP 1 175 343 B1). 
       SUMMARY 
       [0005]    The aim of the invention is to disclose a method by which the filling and sealing of containers is possible with the admission of nitrogen, preferably liquid nitrogen, at least into the headspace of the filled container, with optimum oxygen reduction and however at a sufficient internal pressure of the container, preferably a pressure above atmospheric in the particular filled container. 
         [0006]    In the invention, the charging of the containers or the headspace of the containers not taken up by the filling material, with the liquid nitrogen takes place during a movement phase of the timed movement of the containers, this being preferably in the movement phase of the timed movement immediately before the application or placement of the particular container closure. Achieved in this way, is inter alia, that there remains sufficient time for the evaporation or degassing of the nitrogen and thus sufficient time for the forcing-out of air and oxygen from the headspace of the containers, but at the same time after the final sealing of the particular container, the container has a sufficient internal pressure generated by the nitrogen. 
         [0007]    By way of the method according to the invention, an oxygen reduction is possible without any problem so that far less than 1% of the original oxygen remains in the particular headspace. 
         [0008]    In a preferred embodiment of the method according to the invention, after the charging of the particular container with liquid nitrogen, initially only a “loose” application of the container closure occurs, i.e. an application of the container closure in such a way that while it is secured sufficiently on the particular container, there are gaps between the container closure and the container through which nitrogen, and air, and in particular oxygen forced out by the nitrogen, can flow out. Only after the end of a further period, corresponding approximately to the duration of a movement step of the timed movement with which the containers are moved through the linear installation, or a complete multiple thereof, is the final tight sealing of the containers with the particular container closure carried out. 
         [0009]    The closures are preferably cap-tight closures, for example closures that are fixed by distortion and/or screwing onto the containers or onto the container areas having the container mouth. 
         [0010]    The “headspace” of the containers is the part of the interior of a container underneath the container opening, that is not taken up by the filling material after filling. 
         [0011]    As used herein, the expression “substantially” means deviations from exact values in each case by +/−10%, and preferably by +/−5% and/or deviations in the form of changes that are not significant for functioning. 
         [0012]    Further benefits and application possibilities of the invention arise also from the following description of examples of embodiments and from the figures. In this regard, all characteristics described and/or illustrated individually or in any combination are categorically the subject of the invention, regardless of their inclusion in the claims or reference to them. The content of the claims is also an integral part of the description. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0013]    The invention is explained in more detail below by means of the figures using an example of an embodiment. The following are shown: 
           [0014]      FIG. 1  is a very simplified schematic representation from above of a linear installation for the filling and sealing of containers in the form of bottles under sterile conditions with oxygen reduction and with the establishment of an internal pressure (e.g. pressure above atmospheric) in the sealed container; 
           [0015]      FIG. 2  is a simplified partial representation in side view of the section of the installation in  FIG. 1  having the sealing device; 
           [0016]      FIG. 3  is a partial representation in cross-section of one of the dosing heads of a nitrogen dosing device with a dosing valve and a nozzle opening; 
           [0017]      FIG. 4  in items a) and b) in each case is a partial representation of a container with a container seal after an initial provisional application of the container seal (item a)) and after the final fixing of the container seal (position b)). 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The linear installation generally identified by  1  in  FIG. 1  serves for the filling and sterile sealing of containers  2  in the form of bottles. The containers  2  to be filled and sealed are supplied to the installation  1  by means of a container inlet  3  according to arrow A and are then moved in a multi-lane flow of containers or on a number of movement paths  4 . 1  by a transporter  4  through various sections of the installation  1 , this being, in the embodiment shown, through a pre-treating section  5  for pre-treating the containers  2 , through a filling section  6  for filling the containers  2 , and through a sealing section  7  for sealing the containers under sterile conditions. The containers  2  stand, for example, with their bases on the transporter  4  and are secured against toppling by supporting elements  4 . 2  moved synchronously with them in the area of their container mouth. In an alternative embodiment, the transporter  4  is made for a suspended transportation of the containers  2 . 
         [0019]    The containers  2  filled and sealed in this way are removed by means of a container outlet  8  according to arrow C. The movement of the containers  2  through the sections  5 ,  6  and  7  in transport direction B occurs in a timed manner, i.e. in a stepwise transport movement, in which stationary phases and movement phases follow each other in turn. It is clear that the devices needed for the particular handing of the containers  2  are provided on each movement path  4 . 1 . Furthermore, the containers  2 , which are arranged vertically, i.e. with their container axes oriented in a vertical direction, are moved through sections  5 - 7  so that at least the particular container opening or container mouth  2 . 1  is taken into a sterile chamber  9  ( FIG. 2 ), which at least during the operation of the installation  1  is charged with a sterile medium in the form of gas and/or vapour preferably at a slight pressure above atmospheric, for example with sterile air. 
         [0020]      FIG. 2  shows the section  7  of one of the movement paths  4 . 1  in the area of a sealing device. Illustrated are the containers  2  with their container mouths  2 . 1  arranged in the sterile or aseptic chamber  9  and a closure transfer station  10  and a sealing station  11  following in transport direction B, which is at a distance from the closure transfer station  10  in transport direction B by a timed or movement step of the timed transport movement or by a complete multiple of such a movement step. The cap-type container closures  12  used to seal the containers  2  or the container mouths  2 . 2  are supplied in sterile form, for example after sterilization with a suitable sterilization medium, for example with H 2 O 2  and after drying, by means of a slideway  13  to a closure supply position arranged in the sterile chamber  9  of the closure transfer station  10 . From there, the closures are each placed on a container mouth  2 . 1  with a closure transfer element in the stationary phase of the timed transport movement. Following a further movement cycle of the timed movement, the relevant container  2  is then positioned under the sealing station  11  at which the container closure  12  is definitely fixed in the stationary phase of the timed transport movement on the mouth area, which has the container mouth  2 , of the relevant container  2 , for example by pressing and/or depressing and/or distorting and/or screwing and/or welding and/or sealing etc. 
         [0021]    In relation to the transport direction B before the closure transfer station  10 , in the sterile chamber, a nozzle opening  14  is provided for the dosed supply of liquid nitrogen (N 2 ) into the headspace of the filled containers  2 . The nozzle opening  14 , which is part of a nozzle head  16 , extending into the sterile chamber  9  diagonally from top to bottom, of a nitrogen dosing unit  15 , is arranged in this sterile chamber  9  so that its distance from the closure transfer station  10  or from the area at which the transfer of the particular container closure  12  to a container  2  occurs, in transport direction B is smaller than the distance between the closure transfer station  10  and the sealing station  11  or is smaller than a movement step of the timed transport movement of the containers  2 . Furthermore, the nozzle head  16  and the nozzle opening  14  are arranged such that the axis DA of the nozzle opening  14  encloses, on a vertical or in a substantially vertical plane with the transport direction B, an acute angle α, i.e. an angle α smaller than 45°, that opens in the direction opposite to the transport direction B ( FIG. 3 ). The nozzle opening  14 , which is arranged above the movement path of the container mouths  2 . 1 , is on a level underneath the level of the closure supply position  14  and is generally oriented so that the containers  2  moved past with their container mouths  2 . 1  underneath nozzle  14  and thereby in particular their headspaces are dosed with liquid nitrogen emerging from the nozzle opening  14 . 
         [0022]    For the dosed dispensing of the liquid nitrogen, the nozzle opening  14  is embodied as a dosing valve, this being also with the use of a plunger-type valve body  16 , the pointed end of which extends into the open end of the channel  16  formed in the dosing head  15  and thereby forms the annular nozzle opening  14 . By axial displacement (double arrow D) of the valve body  17 , the nozzle opening can be opened to a greater or lesser extent. 
         [0023]    The described design and arrangement of the dosing head  16  and the nozzle opening  14  not only results in the headspace of the containers  2  moved past the nozzle opening  14  being reliably charged with the liquid nitrogen, but in particular also that sufficient time remains for the expansion, evaporation, or degassing of the liquid nitrogen in the particular headspace and thus for the forcing of air, and in particular, of oxygen, out of the particular headspace. However, the application of the container closures  12  occurs so soon that after the sealing of the particular container  2 , there remains a sufficiently high internal pressure from the nitrogen in the sealed container  2 . 
         [0024]    After the placing of the particular container closure  12  on a container, this container closure  2  is provisionally fixed in its position, but only loosely, so that, with a further evaporation of liquid nitrogen, any oxygen still present is forced out of the headspace of the container together with a certain proportion of the nitrogen. The time available for this corresponds to the distance between the closure transfer station  10  and the sealing station  11 , i.e. the duration of one movement phase of the timed transport movement or a multiple thereof. 
         [0025]    As the nozzle opening  14  is in the way described previously on a level underneath the level of the closure supply position  10 . 1  of the closure transfer station  10 , and the nozzle head  15  is oriented in the way described previously in the container transport direction B, diagonally downwards in the direction of the movement path of the container mouths  2 . 1 , along with the nitrogen emerging from the nozzle opening  14  or along with the resulting and in part rising nitrogen mist, also the gaseous nitrogen on the inside of the container mouth  2 . 1  after the sealing, of the closure  12  waiting in the slideway  13  or already in place in the closure transfer station  10 . 1  of the sealing station  11 , is trapped and oxygen is forced out. Thus, the gas volume on the inside of the particular closure  12 , which is in the closure transfer element of the closure transfer station  10 , is also deprived of oxygen before or while it is placed on a container  2 . In this way, the quality of the oxygen-free or low-oxygen filling and sealing of the containers  2  is quite substantially improved. 
         [0026]    The nozzle head  16  is furthermore formed and arranged or inclined such that its channel  16 . 1  and the inner surface of this channel likewise have an incline from the horizontal in all areas. The channel  16  can thus be completely emptied in particular when the nozzle opening is fully or largely open, namely for example at the end of a production phase or during a cleaning and sterilization phase, in which then not only the nozzle head  16 , but also all other components of the installation  1  are treated with a suitable cleaning and/or sterilization medium. 
         [0027]    In the embodiment shown, at least the final filling of the containers  2  by a filling station  18  occurs a few cycles, generally two to four cycles, before the application of the closures  2  on the filled containers  2 , i.e. in the stationary phase of the timed movement, before the containers are moved in the next movement phase of this movement to the closure transfer station  10  and, in this movement phase before the next stationary phase, are charged with the nitrogen emerging from the nozzle opening  14 . 
         [0028]    In the sterile chamber  9 , preferably only the functional elements, in particular the closure transfer station  10 , the sealing station  11 , the filling station  18  and also the nitrogen dosing units  15  that interact directly with the containers are provided, while the other parts or elements of such stations are disposed outside the sterile chamber  9 , preferably above the sterile chamber  9 , in particular also the device for the supply of the liquid nitrogen emerging at the nozzle opening  14 . 
         [0029]    In section  7 , during the cleaning and sterilization phase in a cleaning and/or sterilization operation of the installation  1 , the cleaning and/or sterilization media used, the media being, for example, vaporous and/or gaseous and/or liquid media, for example H 2 O 2  in aqueous solution at a high concentration and as an aerosol or vapor, are supplied inter alia through the channels  16 . 1  of the nozzle heads  16 , whereby the cleaning and/or sterilization medium emerging at the particular nozzle opening  14  is removed by means of a pipe section  19  arranged directly on the particular nozzle opening  14 . Moreover, during the cleaning and/or sterilization operation, the particular cleaning and/or sterilization medium inter alia, is also supplied to the sterile chamber  9  at suitable places for the cleaning and/or sterilization of this chamber and the functional elements disposed there, and removed again from the chamber  9  for example at places between the movement paths  4 . 1  of the containers  2 . The functional elements used for the supply and removal of the cleaning and/or sterilization media, in particular also pipe sections  19 , are, insofar as they are disruptive during the normal filling and sealing profile, made such that they can be moved or swiveled out of the installation  1  or at least out of the area of movement of the containers  2  for this filling and sealing operation. 
         [0030]    One particular feature of the installation  1  consists inter alia of a dosed treatment of the filled containers  2  with liquid nitrogen in the case of a linear installation  1  or linear machine for the cooling and sealing of the containers  2  under aseptic conditions, wherein a relatively long degassing phase is achieved for the nitrogen for oxygen reduction with nonetheless a safe nitrogen pressure build-up in the containers within tight tolerances. 
         [0031]    The invention has been described above using an example of an embodiment. It is clear that numerous modifications and variations are possible without thereby departing from the inventive idea underlying the invention. 
       REFERENCE DRAWING LIST 
       [0000]    
       
           1  Installation for the filling and sealing of containers 
           2  Container 
           2 . 1  Container mouth 
           3  Container inlet 
           4  Transporter 
           4 . 1  Conveyor belt 
           5 ,  6 , 7  Section 
           8  Container outlet 
           9  Sterile chamber 
           10  Closure transfer station 
           10 . 1  Closure supply position 
           11  Sealing station 
           11 . 1  Sealing element 
           12  Container closure 
           13  Sideway for the closures  12   
           14  Nozzle opening 
           15  Dosing head 
           16  Channel 
           17  Valve body 
           18  Filling element 
           19  Pipe section 
         A, B, C Container transport directions 
         D Axial shift