Closable bag and method and arrangement for aseptic filling thereof

A closable bag of flexible material is provided with a separate inlet member (3) with an opening for filling the bag with a substance, for instance liquid, which inlet member is fastened to the bag. A separate member (7) is arranged for closing the filling opening from inside the bag. The closing member (7) for its closing of the filling opening is arranged for releasable sealing engagement with the inlet member (3), thereby enabling a subsequent partial discharge and reclosing of the bag. The separate inlet and closing members (3, 7) are substantially resistant to deformation and have means (6, 12) for engagement by respective elements of an operating equipment (13-16) arranged outside the bag. The operating equipment includes a filling member connectable to the inlet member, and means for sterilizing a space formed between the filling and closing members.

The present invention relates to a closable bag of flexible material 
provided with a separate inlet member connected to the bag and having an 
opening for filling the bag with material, for instance liquid, and a 
separate member for closing the filling opening from the inside of the 
bag. The invention also relates to a method and arrangement for aseptic 
filling of such a bag. 
A bag of the kind defined above is previously known from GB patent 
application No. 2105291. The known bag in an empty condition prior to 
filling is internally sterilized and sealed by means of a membrane, which 
from the outside of the bag is applied across the filling opening of the 
inlet member. The separate member of the bag for closing of the filling 
opening from the inside of the bag is flexibly formed and is only partly 
fastened to the edges of the inlet member around the filling opening. For 
aseptic filling of the known bag with a sterile or air-sensitive liquid 
material, such as wine, juices, etc., the bag is placed in a supporting 
member which engages the inlet member and moves it to abutment against a 
filling nozzle. The formed space between the latter and the membrane is 
first sterilized by means of a sterilizing gas. Thereafter the liquid is 
supplied through the filling nozzle, the membrane being ruptured by the 
liquid pressure against it so that the filling opening is uncovered. The 
liquid stream then pushes away the partly fastened separate closing member 
so much that a free passage is formed into the bag for the liquid. After 
the filling of the bag, the filling opening is permanently closed by means 
of a heat sealing device, which seals the separate closing member against 
the inlet member. The bag thus known is not suited for an initial 
sterilization of the inlet member by means of steam, as hot steam under 
high pressure could destroy the membrane on the inlet member. This is a 
drawback, as heat sterilization by means of steam is safer and easier to 
control than use of a sterilizing gas. 
Another drawback with the known bag is that it is not possible to utilize 
the inlet member for a total or partial discharge of the bag under aseptic 
conditions, since the separate closing member after filling is permanently 
sealed to the inlet member from the inside of the bag. 
A further drawback with the known bag is that the filling of it is 
time-consuming, since the size of the filling opening is limited by the 
fact that the membrane for strength reasons can have only a relatively 
small extension. Furthermore, the liquid flow into the bag will be 
throttled by the separate closing member partly covering the filling 
opening from the inside of the bag. 
The principal object of the present invention is to avoid the drawbacks 
with the known bag, as described above, by providing a bag of a new kind 
which has a simpler design, is suited for rapid filling with material 
under aseptic conditions, and allows steam to be used for the necessary 
sterilization during the filling operation. Further objects of the 
invention are to provide a simple method and a simple arrangement for 
aseptic filling of the bag. 
These objects are fulfilled according to the invention by a closable bag of 
the initially defined kind which is mainly characterized in that the 
separate inlet and closing members are of stiffer material than the bag 
and are substantially resistant to deformation, that the closing member 
for its closing of the filling opening is arranged for releasable sealing 
engagement with the inlet member, thereby enabling a subsequent partial 
discharge and reclosing of the bag, and that the inlet and closing members 
both have means for engagement with an operating equipment arranged 
outside the bag, such that at least one of said members is movable 
relative to the other for uncovering or closing the filling opening, said 
means being adapted for engagement with the operating equipment when the 
filling opening is uncovered as well as when it is closed and the closing 
member is in sealing engagement with the inlet member. 
In this way the advantage is achieved that steam can be used for 
sterilization of the space which is formed between the filling member and 
the deformation resistant closing member before the filling opening is 
uncovered. Any steam-sensitive membrane of the kind described above is 
thus not necessary. The steam pressure acting to separate the inlet member 
and the closing member can be taken up by the operating equipment, as 
these members both have means for engagement with the latter. Thus, the 
filling opening is kept safely sealed during the steam sterilization. 
As the inlet member and the closing member are of stiffer material than the 
bag and are substantially resistant to deformation and also have no 
membrane, the filling opening can be relatively large for rapid filling of 
the bag. In addition, the operating equipment makes it possible to 
separate the inlet member from the closing member so much that the closing 
member completely uncovers the filling opening and consequently does not 
restrict the inflowing liquid stream during the filling. 
The arrangement of the closing member for releasable sealing engagement 
with the inlet member enables a total or partial discharge of the bag 
content to take place through the filling opening under aseptic 
conditions, as by steam sterilization in the same way as described above 
in connection with filling of the bag. 
In a preferred embodiment of the bag according to the invention, the bag 
comprises two opposed walls, the inlet member being fastened to one of the 
walls and the closing member being fastened to the other wall opposite to 
the inlet member. This achieves the advantage that the closing member and 
the inlet member may perform only a transversal movement relative to each 
other for the closing or uncovering of the filling opening. This means 
that the operating equipment can be made simple so that it will function 
reliably. 
Advantageously, the closing member may be used when filling in a way such 
that inflowing liquid will hit the closing member and be distributed 
thereby within the bag. Thus, the strength of the bag walls no longer 
limit the size of the flow. 
The invention also relates to a method of aseptic filling of the new bag, 
which method is characterized mainly by the following successive steps: 
the bag, internally sterilized and closed, is placed in an operating 
equipment which is caused to engage with both the inlet member and the 
closing member; 
the inlet member is connected to a filling member; 
the space between the filling member and the closing member is sterilized 
by means of a fluid, for instance steam, while the filling opening is kept 
closed; 
the inlet member and the closing member are separated by means of the 
operating equipment for uncovering of the filling opening; 
the bag is filled with material by means of the filling member; 
the inlet member and the closing member are brought together after the 
filling operation by means of the operating equipment for closing of the 
filling opening; 
the inlet member is separated from the filling member; and 
the filled bag is removed from the operating equipment. 
The new bag can also be emptied totally or partially under aseptic 
conditions. In this case the discharge operation comprises the following 
steps: 
the filled bag is placed in a closed condition in an operating equipment, 
which is caused to engage with both the inlet member and the closing 
member; 
the inlet member is connected to a discharge member; 
the space between the discharge member and the closing member is sterilized 
by means of a fluid, preferably steam, while the filling opening is kept 
closed; 
the inlet member and the closing member are separated by means of the 
operating equipment for uncovering of the filling opening; 
the material in the bag is discharged totally or partially by means of the 
discharge member; 
the inlet member and the closing member are brought together after the 
discharging operation by means of the operating equipment for closing of 
the filling opening; 
the inlet member is separated from the discharge member; and 
the totally or partially emptied bag is removed from the operating 
equipment. 
The invention also relates to an arrangement for aseptic filling of the new 
bag. This arrangement is characterized mainly in that the inlet and 
closing members both have means adapted for engagement with an operating 
equipment when the filling opening is uncovered as well as when it is 
closed, that the operating equipment is arranged for moving at least one 
of said members relative to the other for uncovering or closing the 
filling opening, that a filling member is adapted to be connected to the 
inlet member for filling of the bag, and that means are arranged for 
sterilization of the space which is formed before and after the filling of 
the bag between the closing member and filling member while the latter is 
connected to the inlet member. 
In a preferred embodiment of the arrangement according to the invention, 
the operating equipment is arranged for engagement with and operation of 
the closing member from the outside of the bag at a distance from the 
inlet member. It is suitable then to have the closing member sealingly 
fastened around an opening in the bag wall opposite to the inlet member. 
However, it is also possible to arrange the operating equipment for 
engagement with and operation of the closing member through the filling 
opening of the inlet member. Then the closing member need not be fastened 
to the bag. In this case the design of the operating equipment will be 
more complicated, however. Furthermore, filling of the bag will become 
more difficult, since parts of the operating equipment will be located in 
the way of the filling flow into the bag.

As shown in FIG. 1, the bag is made of a thin flexible material and has two 
opposed walls 1 and 2, which have two aligned holes. An inlet member in 
the bag comprises a sleeve 3 which, by means of a radially outward 
directed flange 4 at one end of the sleeve 3, is connected with the 
surrounding edges of one of the holes in the walls. The flange 4 is 
fastened to the inside of the bag wall 1, whereas the sleeve 3 extends out 
from the hole and, with its main part, is situated outside the bag. An 
annular recess 5 is formed in the outside of sleeve 3 near the end of the 
sleeve, which is situated outside the bag, whereby a radially outward 
directed flange 6 is formed at said end for engagement with an operating 
equipment arranged outside the bag (FIGS. 3 and 4). 
A closing member in the bag comprises a sleeve 7 which, at one of its ends, 
has an end wall 8. Its other end has a radially outward directed flange 9. 
By means of its flange 9, sleeve 7 is connected with the surrounding edges 
of the other wall hole in a way such that the flange is fastened to the 
inside of the bag wall 2. The sleeve 7 extends from the wall hole into the 
bag with its axis aligned with the axis of the sleeve 3 of the inlet 
member. Annular protuberances 10 formed on the outside of the sleeve 7 
within the bag are arranged to form seals between sleeve 7 and the inside 
11 of the sleeve 3 of the inlet member (FIG. 2). A flange 12 extends 
radially inward from the inside of the sleeve 7 for engagement with said 
operating equipment arranged outside the bag. Said engagement 
alternatively could be achieved with a shape of the closing member similar 
to the one described above for the sleeve 3 of the inlet member. Then the 
sleeve 7 would have to be formed with a portion extending outside the bag 
in order to expose the radially outward directed flange. 
It is also possible to adapt the operating equipment for engagement with 
the closing member through the filling opening of the inlet member. In 
that case the end wall 8 of the sleeve 7 may be provided with a hole such 
that a radially inward directed flange is formed for engagement with the 
operating equipment. The sleeve 7 then has to be formed with a sealing end 
wall placed at the other end of the sleeve 7 and which replaces the radial 
flange 12. 
The sleeves 3 and 7 of the inlet member and the closing member, 
respectively, preferably are fastened to the bag by heat sealing. Of 
course, in a case like that, the insides of the bag and the sleeves 3 and 
7 consist of a material suited therefor, such as plastics, for instance 
polyethylene. 
The following will describe how the arrangement according to FIGS. 3 and 4 
can be utilized in an aseptic filling of the bag. 
Before filling, the bag--internally sterilized and in a closed 
condition--is to be placed in an operating equipment comprising a rod 
member 13 for engagement with the closing member, and two U-formed forks 
14, 15 for engagement with the inlet member. At one of its ends the rod 
member 13 is provided with a radially expandable device 16, which is 
introduceable into the sleeve 7 of the closing member past the radial 
flange 12. The sleeve 7 is first placed on the rod member 13, which 
engages the sleeve 7 by means of the radially expandable device 16. 
Thereafter the bag is moved by the rod member 13 such that the inlet 
member abuts against a filling member 17 with a supply channel 18 for 
material. The U-formed forks 14, 15 are moved in a radial direction 
towards the recess 5 of the sleeve 3 for engagement with the sleeve 3, 
whereafter the forks 14, 15 force this against the filling member 17 via 
an annular gasket 19 arranged around the opening of the filling member. 
The filling member 17 is provided with a valve 20, which in this stage 
keeps the supply channel 18 closed. The formed space 21 between the sleeve 
7 of the closing member and the valve 20 of the filling member is 
sterilized by means of steam, which is supplied through an inlet 22 in the 
filling member 17. 
After the sterilization of the space 21, the sleeves 3 and 7 are separated 
by moving the rod member 13 in a direction away from the U-formed forks 
14, 15 (FIG. 4). The valve 20 is opened and the bag is filled with 
material by means of the filling member 17. During the filling of the bag, 
the sleeve 7 is held at a distance from the sleeve 3 such that material 
entering the bag will hit the end wall 8 and be distributed by this within 
the bag. 
After the filling operation the supply channel 18 is closed by means of the 
valve 20, and the sleeves 3 and 7 are brought together by moving the rod 
member 13 in a direction towards the U-formed forks 14, 15 to closing of 
the filling opening. Before this is completely closed, material residues 
can be removed from the sleeves 3 and 7 and the filling member 17 by a 
renewed supply of steam. When the filling opening is completely closed, 
the U-formed forks 14, 15 are separated from engagement with the sleeve 3; 
the rod member 13 is moved in a direction away from the filling member 17, 
the bag being separated from this, and the filled bag is removed from the 
operating equipment. 
In order to prevent undue emptying of the content of the bag, the inlet and 
closing members may be sealed to each other in a way such that the flanges 
4 and 9, which are fastened to the bag walls 1 and 2, are connected with 
each other, for instance by heat sealing. In a case like this the bag can 
not be emptied without the formation of a separate discharge opening. 
However, if emptying of the bag is to be performed through the opening in 
the inlet member, the described arrangement is also well adapted for a 
sterile discharge operation. The discharge may be total or partial. 
Then the inlet member is connected to a discharge member similar to the 
filling member 17. After supply of steam for the sterilization of the 
sleeve 3 of the inlet member and the end wall 8 of the closing member, the 
filling opening may be uncovered, and any desired quantity of material may 
be discharged from the bag. Possibly, the discharge member may be 
identical with the filling member if the latter is supplied with means for 
emptying of material from the bag.