Patent Publication Number: US-6659132-B2

Title: Gas permeable sterile closure

Description:
TECHNICAL FIELD 
     The present invention relates, in general, to flexible containers and, more specifically, to large volume, three-dimensional flexible containers. 
     BACKGROUND OF THE INVENTION 
     Containers used for the shipping, storing, and delivery of liquids, such as therapeutic fluids or fluids used in other medical applications, are often fabricated from single-ply or multiply polymeric materials. The materials are typically in sheet form. Two sheets of these materials are placed in overlapping relation, and the overlapping sheets are bonded at their peripheries to define a chamber or pouch for containing the fluids. These types of bags are typically referred to as two-dimensional flexible containers, flat bags, or “pillow bags.” U.S. Pat. No. 4,968,624 issued to Bacehowski et al. and commonly assigned to the assignee of the present application, Baxter International Inc. (“Bacehowski”), discloses a large volume, two-dimensional flexible container. These types of bags can reach volumes as large as 600 liters. 
     While 600 liters is a significant volume for a flexible container, there has been an ever increasing need to provide flexible containers of even greater volumes. This has lead to the development of three-dimensional flexible containers, sometimes referred to as “cubic bags.” 
     In the design and use of three-dimensional flexible containers of such volumes, certain problems are encountered. The large volume of liquid held by the containers exerts a hydraulic force against seams of the container, which in an unsupported state, might be sufficient to cause failure of the container. Indeed, containers this large, when filled with water or some other liquid, can weigh over 3000 pounds. The forces associated with such liquid volumes can cause the container seams to fail or rupture, therefore causing leaks in the container. The liquid held by the container may not be a commodity solution but often a sterile, custom formulated solution. Accordingly, even a very small leak can be costly in that any seam rupture compromises sterility of the entire contents of the container. Also, a failure of a container seam can cause literally hundreds of liters of liquid to escape from the container. This is costly in replacing the lost liquid contents of the container. Clean-up costs are also encountered. 
     These large volume, three-dimensional flexible containers are not intended to be free standing, but rather, are designed to be supported by a rigid or semi-rigid support container commonly referred to as a box or tank. The box can be made of various materials, commonly stainless steel. The stainless steel material is naturally an optical obstruction from seeing into the box. Typically, an operator has to look down into the box from the top. The box may have an access door on a side wall to allow an operator to view the inside of the box. The door, however, is very small in size and cannot provide a full view of the flexible container within the box. The side walls may have a series of small sight openings to allow one determine the level of liquid in the container. Similarly, however, these small sight openings do not allow a full view of the container within the box. 
     By necessity, the box and flexible container will have some interaction. It is desirable for the filled flexible container to transfer the load and associated forces from the contained liquid to the box, so that minimal loads (preferably zero) are carried by the flexible container material, especially the container seams. It is also desirable that the container seams be fully supported to prevent container failures due to “creep,” which refers to the loss of seal integrity due to low but continuous tensile forces. 
     Because of the size of the containers, it may be difficult to properly align the container within the box. While initially properly aligned, the flexible container may shift becoming misaligned during the container filling process. If misaligned, the container can have unwanted folds that do not properly expand when the bag is filled. Such container folds caused from misalignment can result in undue stress on the container seams leading to container failure. 
     For example, as the container is filled with liquid, the container inflates and conforms to the surrounding box. Ideally, the container conforms as close to the inner walls of the box as possible although pleating of the container can occur. At the appropriate time, the liquid is drained from the container wherein the container collapses. If the container is unsupported, it will tend to collapse in horizontal pleats. The pleats can trap liquid within the container thus preventing the container from being fully drained. In some cases, once the container is drained, the container has served its purpose and is then discarded. In other cases, the container may be refilled as part of a larger process. In these instances, a horizontal pleating of the container can restrict the desired realignment during the refilling process. This can result in poor orientation or loss of the effective volume of the container. It may also result in insufficient support of the container. Thus, it is also desirable to vertically support the container within the box to optimize the draining and filling processes. Vertical support of the container within the box is particularly important when filling the container a second time. 
     U.S. Pat. No. 5,988,422 is directed to a sachet for bio-pharmaceutical fluid products. While the sachet is a three-dimensional container, the container does not have optimal angular construction between sides of the container. This will impact how such a container can be supported in a surrounding box. Accordingly, optimal filling, draining, and re-filling of the container cannot be achieved. 
     Some large volume flexible containers often employ a rigid or semi-rigid tube used in the filling and draining of the container, often referred to as a “dip tube.” The dip tube is attached to the top of the container and extends downward to the bottom interior surface of the container. The dip tube supports the center portion of the top panel of the container during draining much like a tent post. In this configuration, the dip tube creates vertical pleats during draining of the container, and also allows a refilling deployment for the container. 
     The dip tube, however, has several disadvantages. First, the dip tube cannot orient the distal vertical surfaces of the container if the container foot print geometry is more complex than a circle. In addition, as the container is drained, the walls of the container converge towards the center essentially creating loads of compression on the non-compliant dip tube. These compressive forces can cause several problems. The dip tube itself can buckle under these forces. The seal between the dip tube and the top of the container can be compromised. A bottom portion of the dip tube can also rupture the bottom of the container. Using a dip tube structure also increases the cost the container system. In addition, dip tubes are also often accompanied by a container vent to allow incoming air to displace fluid instead of collapsing the container material. Finally, the dip tube also provides another potential mode of contamination ingress to the contents of the container. Thus, there remains a need for a vertical support system for the container within the box that addresses the needs of draining and refilling without the added complexity of dip tubes and vents. 
     These large volume containers are also typically equipped with one or more ports equipped with a port closure for accessing the fluid within the container. The container may have the port in a bottom panel that opens into the container. Oftentimes, the port closure includes a tube having one end connected to the port. Because the container is often used in medical and biotechnical applications, the port closure must include means for maintaining the other free end of the tube free from contamination. In other words, the free end of the tube must be equipped with a sterile closure that prevents potential contaminants from entering the tube and container. It is also desirable, however, to allow air to enter the container because it facilitates manipulation of the container during handling and installation. 
     There are two common approaches for providing a sterile closure at the free end of the tube. First, the free end of the tube can be sealed shut. In this application, the tubing must be selected from a thermoplastic material such as PVC or polyethylene that permits sealing of the material. This material can be heat sealed or sealed using other sealing energies such as radio frequency or ultrasonics. Using a silicone tube is desirable in the manufacturing process applications where the container is used. For example, a pump can be connected to the tubing for long periods of time so that the fluid can be pumped from the container. The silicone tubing also has the ability to withstand high temperatures, especially when the end of the tube is sterilized using steam in place (S.I.P.) methodologies. One problem that exists in using a sealed silicone tube, however, is that while providing a sterile closure, it does not facilitate the free passage of gases. Gas transfer (venting) is desirable to facilitate manipulation of the container during handling and installation. In addition, to access a container having a sealed tube, an operator must use a sharp implement such as a knife, blade or other cutting utensil to open the tube. This introduces an opportunity to contaminate the tube, and also poses a risk of injury to the operator. 
     The second approach for providing a sterile closure at the free end of the tube is to use a formed element such as an injection molded part or stainless steel coupling. The tubing is fitted to the part or coupling, and then the part or coupling is covered with another mating injection molded part or coupling. Similar to the sealed tube approach, such fittings provide a sterile closure but do not provide for gas transfer without loss of sterility. In addition, using injected molded parts or stainless steel couplings is costly. 
     The present invention is provided to solve these and other problems. 
     SUMMARY OF THE INVENTION 
     The present invention relates to containers and, in particular, to large volume, three-dimensional flexible containers. 
     According to a first aspect of the invention, a container is provided having a plurality of panels joined together to form a sleeve. The panels each have an end edge that cooperate to define an imaginary plane at one end of the sleeve. The container further has an end panel connected to the panels at the one end of the sleeve. The end panel has at least one portion extending beyond the imaginary plane. According to another aspect of the invention, the panels form a polygonal sleeve. The portion of the end panel extends outwardly from the sleeve. Alternatively, the portion could extend inwardly towards the sleeve. 
     According to a further aspect of the invention, a large volume flexible container capable of containing a fluid to be maintained under sterile conditions is provided. The container has a first panel, a second panel, a third panel, and a fourth panel connected together to form a generally cubic structure. The first panel has a central segment adjacent an end segment. The central segment has a longitudinal edge and the end segment has a tapered edge extending from the longitudinal edge. An angle is defined between the longitudinal edge and the tapered edge. The angle is in the range from about 135.01° to about 138°. In a most preferred embodiment, the angle is 136°. This angle is maintained when the panels of the container  10  are welded together. 
     According to a further aspect of the invention, a support container, or box, is provided for supporting the three-dimensional flexible medical container filled with fluid. The box has a frame having a top portion and a bottom portion. The frame has a plurality of sidewalls connected together at their extremities forming a chamber therein. The frame further has a floor spaced from the bottom portion. The chamber is sized to receive the flexible medical container wherein a bottom wall of the container is supported by the floor and sidewalls of the container are supported by sidewalls of the frame. Each sidewall supports a generally transparent panel, preferably a polycarbonate panel, such as Lexan™. 
     According to another aspect of the invention, a hanger system is provided for providing vertical support of the container supported within the box. A support member is connected to a top portion of the box. A hanger is provided having a plurality of depending members adapted to be connected to an end panel of the container. The hanger is connected to the support member. In a preferred embodiment, the hanger includes a first member and a second member connected together substantially at their respective midportions to form an x-shaped member. The depending members are pivotally connected to ends of the hanger members. 
     According to yet another aspect of the invention, a port closure for the container is provided. The port closure provides a means for providing a sterile and gas permeable barrier over the port. In one embodiment, the port closure has a communication member having a first end and a second end, the first end adapted to be in communication with the container. A stop member is inserted into the second end of the communication member wherein the stop member is made from a porous material. A cover member is provided and receives the second end of the communication member. The cover member is releasably secured to the communication member. In a preferred embodiment, the communication member is a tube made from a thermoplastic material. The stop member is a plug. An elastic band is wrapped about the pouch and the communication member releasably securing the cover member to the communication member. A tamper evident feature can also be incorporated into the port closure. 
     Other advantages and aspects of the present invention will become apparent upon reading the following description of the drawings and detailed description of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a medical fluid container of the present invention; 
     FIG. 2 is a perspective view of another medical fluid container of the present invention that is larger than the container shown in FIG. 1; 
     FIG. 3 is a perspective view of another medical fluid container of the present invention that is larger than the containers shown in FIGS. 1 and 2, and shown in a vertical configuration; 
     FIG. 4 is a side elevation view of the container of FIG. 1; 
     FIG. 5 is a plan view of a panel of the container; 
     FIG. 6 is a plan view of a gusseted panel of the container; 
     FIG. 7 is a perspective view of an end panel of the container; 
     FIG. 8 is a perspective view of the container of the present invention in a generally folded configuration, a supporting box being shown in phantom lines; 
     FIG. 9 is a perspective view of the container of FIG. 8 filled with fluid during a filling process; 
     FIG. 10 is a perspective view of a box used to support the container, the container being positioned in the box; 
     FIG. 11 is a front elevation view of a container of the present invention supported in a box and utilizing a container hanger system; 
     FIG. 12 is a side elevation view of the container of the present invention supported in the box utilizing the container hanger system; 
     FIG. 13 is a perspective view of the container hanger system of the present invention; 
     FIG. 14 is a top view of the container in the box of FIG. 13 wherein the container is partially drained; 
     FIG. 15 is a schematic perspective view of an alternative embodiment of the container hanger system of the present invention; 
     FIG. 16 is a schematic perspective view of another alternative embodiment of the container system of the present invention; 
     FIGS. 17 a-e  are schematic views of a draining process of the container supported by the container hanger system; 
     FIG. 18 is a plan view of a port closure used with the container; 
     FIG. 19 is a plan view of the port closure of FIG. 18 in an alternative configuration; 
     FIG. 20 is a perspective view of a port closure connected to a container; 
     FIG. 21 is a perspective view of a container having multiple ports with a port closure connected at one port and an alternative port closure connected at the other port; 
     FIG. 22 is a plan view of the container positioned in the box, the container being partially filled; 
     FIG. 23 is a plan view of the container positioned in the box, the container being substantially filled; 
     FIG. 24 is a partial enlarged view of a corner portion of a container positioned in a box; 
     FIG. 25 is a partial enlarged view of the container of the present invention in the box; 
     FIG. 26 is schematic perspective view of an alternative embodiment of the container hanger system of the present invention; and 
     FIG. 27 is a schematic perspective view of an alternative embodiment of the container hanger system of the present invention. 
    
    
     DETAILED DESCRIPTION 
     While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. 
     Referring to the drawings, FIG. 1 shows a container made in accordance with the present invention generally referred to with the reference numeral  10 . The container  10  is a three-dimensional container capable of holding large amounts of fluid. The container  10  shown in FIG. 1 holds approximately 200 liters of fluid. The container  10 , however, can be made in a variety of sizes. For example, FIG. 2 shows a container  10  sized to hold approximately 500 liters of fluid, and FIG. 3 shows a container  10  sized to hold approximately 1500 liters of fluid. The container  10  has a unique configuration that reduces seam stress to the container  10  caused by hydraulic forces generated from the fluid held in the container  10 . 
     As shown in FIG. 1, the container  10  is three-dimensional and generally has a rectangular shape having six sides, or sometimes referred to as having four sides and two ends. 
     The container  10  is generally formed from four panels: a first panel  12  or top panel  12 , a second panel  14  or bottom panel  14 , a first side gusseted panel  16  and a second side gusseted panel  18 . These walls  12 - 18  form four panels of the container and end portions of each wall cooperate to form the remaining two panels of the three-dimensional container  10 , a first gusseted end panel  20  and a second gusseted end panel  22 . The individual walls will first be described and then the connections between the walls will be described to show the structure of the container  10 . 
     FIG. 5 shows a plan view of the first panel  12  or top panel  12 . It is understood that the second panel  14  or bottom panel  14  has a similar structure and will not be individually described. The top panel  12  generally has a central segment  24 , a first end segment  26  and a second end segment  28 . A fold line FL represents an interface between the central segment  24  and the end segments  26 , 28 . The end segments  26 , 28  are folded and cooperate with end segments of the other panels to cooperatively form the end panels  20 , 22  as will be described in greater detail below. 
     As further shown in FIG. 5, the top panel  12  has a first peripheral edge  30  and a second peripheral edge  32 . Each peripheral edge  30 , 32  has a longitudinal portion  34  at the central segment  24  and a tapered portion  36  at the first end segment  26  and the second end segment  28 . At each end segment  26 , 28 , the tapered portions  36  converge toward one another but do not meet. Rather, the tapered portions  36  meet an end edge  38 . As will be described in greater detail below, the longitudinal portion  34  of the peripheral edge  30 , 32  meets the tapered portion  36  at an angle A. Similarly, an angle B exists between the tapered portion  36  and the fold line FL. Preferred measurements of the angles A and B will be described in greater detail below that optimize the seam strength of the container  10 . The top panel  12  can include a port  40  if desired. The bottom panel  14  could also have a port  40 . An additional port  41  could also be provided (FIG.  1 ). It is understood that a port could be placed in any panel of the container  10 . 
     FIG. 6 discloses a plan view of the first side gusseted panel  16 . It is understood that the second side gusseted panel  18  has similar structure and will not be separately described. The first side gusseted panel  16  also has a gusset central segment  42 , a first gusset end segment  44  and a second gusset end segment  46 . A fold line FL represents an interface between the gusset central segment  42  and the gusset end segments  44 , 46 . The gusset end segments  44 , 46  are folded and cooperate with top and bottom panel  12 , 14  end segments  26 , 28  to cooperatively form the end panels  20 , 22  as will be described in greater detail below. 
     As further shown in FIG. 6, the gusseted panel  16  has a first peripheral edge  48  and a second peripheral edge  50 . Each peripheral edge  48 , 50  has a longitudinal portion  52  at the central segment  42  and a tapered portion  54  at the first gusset end segment  44  and the second gusset end segment  46 . At each gusset end segment  44 , 46 , the tapered portions  54  converge toward one another and meet at a point  56 . As will be disclosed, the gusseted panels  16 , 18  have a gusset fold GF at generally a center-line of the panel. The panels  16 , 18  fold inwardly at the gusset fold GF. 
     In constructing the container  10  into a three-dimensional form, the peripheral edges of the panels  12 - 18  are generally joined by suitable means known in the art, such as heat energies, RF energies, sonics or other sealing energies. The first and second gusseted side panels  16 , 18  are positioned to space the top panel  12  and the bottom panel  14 . The peripheral edges of the top panel  12  are sealed to respective peripheral edges of the gusseted side panels  16 , 18  to form seams. Similarly, the peripheral edges of the bottom panel  14  are sealed to the opposite peripheral edges of the gusseted side panels  16 , 18 . Specifically, for example, the peripheral edge  30  of the top panel  12  is sealed to the peripheral edge  48  of the first gusset panel  16  wherein the respective longitudinal portions  34 , 52  are sealed together to form a side seam  60  (FIG.  1 ), and the respective tapered portions  36 , 54  are sealed together to form end panel seams  62 . In this fashion, and as shown in FIG. 1, the flexible container  10  is formed having a generally three-dimensional rectangular shape. The central segments  24 , 42  of the panels  12 - 18  form the sides of the container  10 . The end segments  26 , 28  of the first and second panels  12 , 14  and the end segments  44 , 46  of the gusseted side panels  16 , 18  cooperate to form the gusseted end panels  20 , 22 . In this configuration, the end segments  26 , 28 , 44 , 46  serve as connecting members to form the end panels  20 , 22 . The end segments converge towards one another and can be configured to join at a point, a line or a polygon. In a preferred embodiment, the end segments converge to a line. It is further understood that the container  10  can be configured into any number of N-sided polygonal shapes. It is further understood that the individual panels could be comprised of a plurality of separate panels connected together to form the panels of the container  10 . This may be done, for example, in making a container  10  even larger than the 1500 L container shown in FIG.  3 . 
     In a typical construction of a three-dimensional container, angle B would be 45° creating the angle A (FIG. 5) between the longitudinal portion  34  and tapered portion  36  of the peripheral edge  30 , 32  of 135°. This would provide a construction such that the end panels  20 , 22  would be generally perpendicular to the central segments  24 , 42  of the panels  12 - 18 . In the container  10  of the present invention, the angle A is increased from 135° to within a range from about 135.01° to 138°. In a most preferred embodiment, the angle A is about 136°. By increasing this angle, more material is provided in the gusseted end panels  20 , 22 . As shown in FIG. 4, this extra material allows the end panels  20 , 22  to extend outwardly from the central segments  24 , 42  providing a “pent roof” (See FIGS. 2,  4  and  7 ). As further shown in FIG. 4, the panels  12 - 18 , when connected together form a sleeve  64 . In the preferred embodiment, the sleeve  64  is in the form of a rectangular parallelpiped shape. The panels each have an end edge  63  that correspond to the end of the central segments  24 , 42  at the fold lines FL. The end edges  63  define an imaginary plane P at the end of the sleeve  64 . The end panel  20 , 22  has at least one portion that extends beyond the imaginary plane P. In a most preferred embodiment, the end panel is contiguous with the sleeve and the entire end panel  20 , 22  extends beyond the imaginary plane P. In this configuration, the end edges of the sleeve  64  are represented by the fold lines FL. With this extended configuration, when the container  10  is filled with liquid, stresses on the end panel seams  62  are reduced. This also prevents additional stresses from being transferred to other portions of the container  10 . 
     FIGS. 8 and 9 disclose a filling process for the container  10  such as shown in FIGS. 1 and 2, e.g. a container  10  in a horizontal configuration. For initial clarity, the container  10  is shown out of the supporting box (to be described) although it is understood that the container  10  is filled with liquid after being positioned in the box. The container  10  is positioned horizontally with the bottom panel  14  against the base of the box. The container  10  is flattened wherein the first and second gusseted side panels  16 , 18  can be folded inward to the container  10  although they are shown extended in FIG.  8 . The gusseted end panels  20 , 22  are folded over on top of the top panel  12  when the container is in a supporting box. In this configuration, the container is easily filled. As shown FIG. 9, as the container  10  is filled, the gusseted side panels  16 , 18  begin unfolding. Because each panel  16 , 18  has a single horizontal fold GF, as opposed to vertical gusset folds, there is less of a chance for the panels  16 , 18  to hang-up against the box and not fully unfold. If the panels  16 , 18  hang-up against the box, it prevents the container  10  from being fully inflated, which can place undue stress on the container seams during filling and transportation of the container  10 . FIG. 9 shows the container  10  partially filled. 
     FIG. 2 discloses another container  10  that is designed to hold approximately 500 liters. FIG. 3 discloses an even larger container  10  designed to hold approximately 1500 liters. In containers  10  of the size shown in FIG. 3, it is sometimes desirable to configure the container such that gusseted end panels  20 , 22  are at the top and bottom of the container  10 . Containers of this configuration can be as much as 15 feet in height. This gives the container  10  a smaller footprint, which is desirable so it can be carried on a standard pallet. A vertical footprint also minimizes the floor space occupied by the container, which can be important in storing a large quantity of containers. The container  10  has a generally rectangular footprint which provides a greater overall volume than a generally cylindrical container of the same height. It is understood that in a container  10  having a vertical configuration (FIG.  3 ), one of the end panels  20 , 22  may be referred to as a bottom panel such as end panel  20  shown in FIG.  3 . 
     The container  10  of the present invention is not designed to be self-supporting, but is rather supported by a supporting container  100  or rigid box  100 . FIGS. 10-12 disclose the box  100  that supports the container  10 . The box  100  disclosed in FIGS. 10-12 is designed to support a container  10  in a vertical configuration such as shown in FIG. 3 although it is understood that a box  100  can be configured to support a container  10  in a horizontal configuration. The box has an outer frame made up of a plurality of frame members  102 . The frame members  102  are connected together to form a front wall  104 , a rear wall  106  and two sidewalls  108 , 110 . The walls  104 - 110  are connected together to form a chamber having a generally square or rectangular cross-section. Each wall  104 - 110  has vertical members  112  and cross-members  114  to add rigidity to the walls. A bottom portion of the vertical members  112  are adapted to rest on a supporting floor surface. The frame members  102  of each wall  104 - 110  support a panel  113 . In a most preferred embodiment, the panels are clear polycarbonate panels such as Lexan™ panels. The frame members  102  of the walls  104 - 110  and the panels  113  cooperate and are referred to as side panels of the box  100 . The front wall  104  has a door  105  that is removably connected to the front wall  104 . The door  105  allows access to the inside of the box  100  prior to filling the container  10  placed in the box  100 . The box  110  further has a bottom wall  116  that is positioned inward from the bottom portions of the vertical members  112  so that the bottom wall  116  is slightly raised from the supporting floor surface. The bottom wall  116  has a first opening  118  and a second opening  120 . These openings  118 , 120  will correspond to the ports  40 , 41  located on the container  10 . The openings  118 , 120  help to properly locate the container  10  within the box  100 . The top portion of the box  100  is open and is designed to receive the flexible container  10 . When the flexible container  10  is inserted into the box  100 , a discharge port and hose connected to the container (See e.g., FIG. 20) is fed through the first opening  118 . The container  10  will also have a second port  41 , which may be closed, that is inserted into the second opening  120  and assists in further properly locating the container  10  within the box  100 . The container  10  is positioned such that the bottom panel  20  of the container  10  is supported by the bottom wall  116  and the corners of the bottom panel  20  of the container  10  are positioned substantially at the corners of the bottom wall  116 . The container  10  is then connected to the hanger system to be described and then is ready to be filled. 
     FIGS. 10-17 disclose a hanger system  150  used in accordance with the present invention. The hanger system  150  is utilized to support the empty upper portion of the container  10  to optimize filling and draining of the container  10 . For clarity, only a portion of the box  100  is shown in FIGS. 13,  15  and  16 . The hanger system  150  generally includes a hanger  152 , a support member  154 , a cable  156  and a counterweight system  158 . 
     As shown in FIG. 13, the hanger  150  has a first member  160  and a second member  162  connected together substantially at their respective midportions to form an x-shaped member. The angles between the members  160 , 162  could vary as desired. In one preferred embodiment, an angle A is approximately 70° and an angle B is approximately 110°. The first member  160  has a first end  164  and a second end  166 . The second member  162  has a first end  168  and a second end  170 . The hanger  150  serves as a spreader member wherein the ends of the members  160 , 162  spread out over the end panel or top panel  22  of the flexible container  10 . Each end  164 - 170  has a depending member  172  extending downwardly therefrom. In a preferred embodiment, the depending members  172  are pivotally connected to the first member  160  and second member  162 . The pivotal connection provides benefits in the draining process and the filling process as will be described below. The depending members  172  each have a protrusion that is received in an eyelet  173  connected to the container  10  to hang the container  10  from the hanger  152 . In a preferred embodiment, and as shown in FIG. 7, the eyelets  173  are located along a diagonal seam between 35% and 65% of the length of the seam as measured from an outer corner C of the filled container  10 . It is understood that the hanger members  160 , 162  can have different lengths to accommodate containers  10  of different sizes. The hanger  152  provides a spider-shaped support configuration that spreads out the container  10  so that the container  10  fills up with fluid with a minimum amount of pleating against the Lexan™ panels  113  of the side panels of the box  100 . It is further understood that the number of members and depending members of the hanger  152  could vary depending on the size of the container  10  and the desired hanging configuration. 
     As shown in FIGS. 11 and 12, the support member  154  is generally an overhead support bracket  154 . The support bracket  154  has a first post  174  and a second post  176  connected by a cross rail  178 . The first post  174  is connected to one side of the top portion of the box  100  and the second post  176  is connected to an opposite side of the top portion of the box  100 . Thus, the cross-rail  178  spans over the open top portion of the box  100 . In its simplest form, the container  10  is adapted to be hung from the hanger  152  by the cable  156  that is connected between the hanger  156  and the support member  154 . 
     The counterweight system  158  generally includes a first pulley  180 , a second pulley  182 , and a counterweight  184 . The counterweight system  158  allows tension adjustment to the upper portion of the container  10 . The first pulley  180  is connected to the cross rail  178  and the second pulley  182  is connected to a side of the box  100 . The hanger system  150  is connected such that a first end  186  of the cable  156  is connected to the hanger  152  and a second end  188  of the cable  156  is connected to the counterweight  184 . The counterweight  184  is suspended outside and adjacent to the box  100 . The cable  156  passes over the first pulley  180  and the second pulley  182 . The hanger system  150  provides an upward biasing force to the top portion of the flexible container  10 . By changing the weight of the counterweight  184 , tension on the container  10  can be adjusted, in keeping with the volume of the container  10 . 
     FIGS. 15 and 16 disclose alternative embodiments of hanger systems for the container  10 . FIG. 15 discloses a hanger system  200  having a hanger  202 . The hanger  202  has a plurality of cables  204  that depend from the hanger  202  and are connected to the container  10 . The hanger  202  acts to spread the cables  204  to prevent tangling. The hanger system  200  is hung from the support member  154  and has a counterweight system  158 . FIG. 16 discloses another hanger system  210 . The hanger system  210  has a first flexible member  212  and a second flexible member  214  connected together substantially at their respective midportions. The ends of the flexible members  212 , 214  are adapted to be connected to the container  10 . The flexible members  212 , 214  have a curved configuration. The hanger system  210  would be hung from the support member  154  and would also utilize the counterweight system  158 . When the container  10  is initially hung, the members  212 , 214  bend towards a downward U-shape. During the filling of the container  10 , the members  212 , 214  would straighten as the top panel of the container transitioned from a vertical configuration to a horizontal configuration. It is understood that the hangers of the hanger system of the present invention could be modified to include a additional members such as to be employed with any N-sided polygon foot print with at least one connection per corner. 
     FIGS. 26 and 27 disclose additional alternative embodiments of hanger systems for the container  10 . FIG. 26 discloses a spring assembly  400  that is mounted to a top portion of the supporting box  100 , shown schematically. The spring assembly  400  has a rod  402  having cords  404  extending from and connected to the rod  402 . The rod  402  is rotatably biased to wind the cords on the rod  402 . This provides an upward biasing force on the container  10 . As shown in FIG. 27, two spring assemblies  400  can also be provided. It is further understood that additional spring assemblies  400  could be employed as desired. 
     It is further understood that hanger systems having different configurations to provide an upward biasing force on the container  10  are possible. For example, springs could be employed between the box  100  and container  10 . Other elastic members could be configured to apply an upward force on the container. Another box could be utilized and connected to the box  100  in a coaxial fashion. A cylinder assembly could be connected between the two coaxial boxes to provide an upward biasing force or tension on an upper portion of the container  10 . 
     Once the container  10  is placed in the box  100  and hung using the hanger system  150 , the container  10  can be filled. Fluid is pumped using, for example a peristaltic pump (not shown) that can be attached to a side portion of the box  100 . The pump will pump fluid through the port hose attached to the port  40  on the bottom panel  20  of the container  10  (FIG.  3 ). The hanging system  150  helps to suspend the container  10  uniformly within the box  100  such that there is a minimum amount of pleating of the container  10  against the side panels of the box  100 . Also, the hanger system  150  permits full deployment of the bottom panel  20  of the container  10  along the contours of the bottom floor  116  of the box  100 . As the container  10  continues to be filled, the sidewalls of the container  10  deploy substantially uniformly against the side panels of the box  100 . As the container  10  nears its full volume, the pivoting depending members  172  pivot as the top panel  22  of the container  10  transitions from a generally vertical configuration to a substantially horizontal configuration. 
     Once filled, the container  10  is ready to be attached, for example, as part of a subsequent process. Such process may require the container  10  to be drained to deliver the fluid to another location for further processing. In this situation, the pump will pump fluid from the container  10 . As fluid is pumped from the container  10 , the counterweight  184  maintains an upwardly biasing force on the container  10  to assist in the draining process. FIGS. 17 a - 17   e  schematically disclose a draining process of a flexible container  10  in the vertical configuration being vertically supported by the hanger system  150 . As shown in FIGS. 17 a - 17   c , the flexible container  10  pulls away from the box  100  as the container  10  is drained. The container  10  begins collapsing at the outermost corners of the container  10  because of the location of the connecting points with the depending members  172 . The resulting shape is peaked with the volume reduction of the emptying container  10  defined by inward peaked folding pleats. As shown in FIGS. 17 d  and  17   e , the defining shape is tent-like with the formation of vertical wrinkles  185 . The vertical wrinkles  185  are defined between the hanger connection points and the draining level of the fluid within the container  10 . Vertical wrinkles are more desirable than horizontal pleats as vertical wrinkles will allow greater deployment of the container  10  within the box  100  during a refilling process. As shown in FIG. 17 e , as the fluid is pumped out, and with the corners of the bottom panel of the container  10  placed appropriately at the corners of the box  100 , the bottom panel of the container  10  is sucked convex upward away from the intermediate floor of the box  100  by the evacuating action of the draining pump. This defines drainage points on the container  10  allowing fluid to run downwardly on this surface to the port  40 . As shown in FIG. 14, the depending members  172  pivot inwardly as the top panel shifts from a substantially horizontal configuration to a more vertical configuration. 
     During a refilling process, the pump pumps fluid back into the container through the same port  40  at the bottom panel  20  of the container  10 . The convex upward configuration of the bottom panel  20  is re-contoured to the bottom floor  116  of the box  100  by the weight of the fluid. The fluid also then refills the lower corners of the bottom panel  20  at the junction of the vertical wrinkles  185  on the side panels of the container  10 . During the refilling of the container  10 , the vertical wrinkles  185  are once again defined by the level of the fluid pushing the material towards the corners of the box  100  and by the upward connection of the hanger  152 . Because of the configuration of the hanger  152  and its connection to the top panel of the container  10 , the corners of the container  10 , as the container  10  is filled, tend to assist one another in positioned themselves at the corners of the box  100 . Because the wrinkles  185  are in a vertical configuration, the wrinkles  185  do not get trapped against the side panels of the box  100  as a horizontal fold would get trapped. The vertical wrinkles  185  rather open and deploy against the side panels of the box  100 . 
     The hanger system  150  provides several advantages. The hanger system  150  permits the use of large volume flexible containers having a single port for use in applications that require filling, draining and then refilling without the additional expense and hazards that may be associated with flexible containers containing dip tube or vent design features. The hanger system  150  also permits complete collapse of the filled container  10  during the draining process without having to admit air into the container  10 , thereby maintaining a closed system. The system  150  further provides support for refill deployment of the container  10  which minimizes undesirable pleating of the container  10 . The system  150  forces the collapse of the container during draining to occur with predominately vertical wrinkles as opposed to horizontal creases that can prevent redeployment of the container  10  during refilling. This vertical collapsing configuration greatly improves the drainage performance of the container as the bottom panel of the container  10  is sucked convex upward defining lower drainage points on the container  10 . 
     FIGS. 22 and 23 disclose a further aspect of the invention. The flexible container  10  is sized to be larger than the box  100 . In this configuration, the amount of stress on the container seams is minimized if the container  10 , for example, does not become optimally aligned within the box wherein the four corners of the container are substantially adjacent the four corners of the box. FIG. 22 discloses a schematic plan view of the container  10  within the box  100 . The container  10  is only partially filled with fluid. The panels of the container are defined by a container width CW and a container depth CD. The panels of the container  10  cooperate to define a first perimeter P 1 , i.e. P 1 =2*(CW+CD). The side panels of the box are defined by a box width BW and a box depth BD. The panels of the box cooperate to define a second perimeter P 2 , i.e. P 2 =2*(BW+BD). The panels of the container  10  are sized such that the first perimeter P 1  is larger than the second perimeter P 2 . This allows for some “play” with respect to the container  10  within the box  100  and will provide a certain amount of wrinkles in the container  10  preferably at the corners of the container  10  and box  100 . In a preferred embodiment, the container  10  is sized with respect to the box  100  so that the first perimeter P 1  is about 2% to about 10% larger than the second perimeter P 2  of the box  100 . As shown in FIG. 23, when the container  10  is substantially filled with fluid within the box  100 , wrinkles are formed in the container  10  at or near the corners. If the container  10  was sized substantially identically to the box  100 , corners of the container  10  could pull away from the corners as shown in FIG. 24 thus putting more stress on the container  10 . As shown in FIG. 25, a larger sized container  10  alleviates these potential problems wherein corners of the container  10  are optimally supported at corners of the box  100 . 
     FIGS. 18-21 disclose a port closure  300  according to the present invention designed to provide a unique closure for the port  40  of the container  10 . The port closure  300  provides both a sterile and gas permeable barrier. The port closure  300  generally includes a communication member  302 , a stop member  304 , a cover member  306  and a band  308 . The communication member  302  is typically in the form of a tube. The tube  302  is typically made from an elastomeric material such as silicone. The size of the tube can vary depending on the particular application. In one preferred embodiment, a ¾ in. tube is used. The tube  302  has a first end and a second end, and the length of the tube is determined by the desired application. The stop member is typically in the form of a plug  304 . The plug  304  is typically cylindrical and selected from material that is porous but has hydrophobic properties such that it allows gases such as air to pass through the plug  304  but prevents fluid from passing through the plug  304 . In one preferred embodiment, the plug  304  is made from a porous plastic material such as polyethylene. Polytetrafluouroethylene material could also be used. Other materials are also possible and materials can be used after being treated to possess hydrophobic properties. The pore size of the material is sized so that it is capable of providing a gas permeable, sterile barrier. In a most preferred embodiment, the plug is a commercially-available Porex®hydrophobic material. The plug  304  is generally about 1 inch in length and has a diameter sized such that it will form an interference fit when inserted into an end of the tube  302 . As further shown in FIGS. 18-20, the cover member  306  has a first member  310  and a second member  312 . The members  310 , 312  can be made from cellophane or paper. In addition, one member can be paper and one member can be cellophane. As explained in greater detail below, the members  310 , 312  are sealed to one another to form a two-ply, peelable pouch having an opening to receive the second end of the tube  302 . The band  308  is typically also made from elastic material such as silicone and can be cut from tube stock identical to the tube used in the port closure  300 . 
     As further shown in FIG. 20, in constructing and connecting the port closure  300  to the container  10 , the tube  302  is first cut to the desired length, e.g. 6-30 feet of tubing. A first end  314  of the tube  302  is inserted over the port  40  on the container  10  to form an interference fit. A cable tie  316  can be placed around the first end  314  of the tube  302  when installed on the port  40  to more securely connect the tube  302  over the port  40 . After tightening, the cable tie  316  is trimmed accordingly. The plug  304  is cut into a one inch length from the desired plug stock. As shown in FIGS. 18 and 19, the plug  304  is then inserted into a second end  318  of the tube  302 . A portion of the plug  304  extends from the second end of the tube  302  to allow the operator to grasp the plug  304  on removal from the tube  302 . The first and second members  310 , 312  of the cover  306  are sealed to one another but leaving one open end  320  (FIG. 20) to form a pouch  322 . The cover  306  is then placed over the second end  318  of the tube  302  and plug  304 . The band  308  is then placed around the cover  306  and the tube  302  to secure the cover  306  to the tube  302 . Because the elastic band  308  is cut from tube stock identical to the tube  302 , when the band  308  is placed around the tube  302 , it provides a radially compressive force on the cover  306  against the tube  302 . The cover  306  provides a dustcover so that if the second end  318  of the tube  302  is inadvertently dropped on the floor or otherwise touch contaminated, the porous plug  304  and tube end  318  remains clean and sterile. If a tamper evident feature is desired, the cover member  306  may be permanently affixed to the second end  318  of the tube  302  with a non-removable accessory such as a shrink band  309  (FIG.  19 ). In addition, as shown in FIG. 18, the cover  306  could be directly heat sealed to the tube  302  thus providing a tamper evident feature. 
     There are two general methods to access the plug  304  at the second end  318  of the tube  302 . As shown in FIG. 18, top edges  324  of the first and second members  310 , 312  can be peeled apart to open the cover  306 . Alternatively as shown in FIG. 19, the band  308  can be rolled down the tube  302  and the cover  306  pulled away from the second end  318  of the tube  302 . In either case, once the cover  306  is removed, the plug  304  can also be removed wherein the fluid can either be drained or pumped from the container  10 . 
     In certain instances, a container may have a plurality of ports, e.g. a fill port, a drain port and a vent port. FIG. 21 discloses a container  10  having an additional port  330  closed by a vent closure  332 . The vent closure  332  is similar to the port closure  300  described above. The vent closure  332  has a short silicon tube  334  having one end connected to the additional port  330 . A vent plug  336  made from the same material as the port closure plug  304  is inserted into the free end of the tube  334 . The vent plug  336  allows gases to pass therethrough to equalize pressure inside the container  10  to the pressure outside the container  10 . The vent plug  336  enables complete filling of the container  10  and attendant reduction of headspace (i.e., the space of the fluid level and the top of the container). This is an advantage in a stationary container application because uncontrolled headspace can cause an alteration in the gas concentrations in the fluid, thus permitting a shift in the pH of the fluid. In a container  10  that is to be transported, headspace is a particularly critical issue, because headspace will allow sloshing of the fluid during shipping. Such fluid movement can cause degradation of proteins in the fluid due to denaturation (foaming), as well as compromising the container itself due to repeated mechanical stresses (flex cracking). 
     As further shown in FIG. 21, if desired, a valve  338  can be positioned within the tube  334 , or communication member, in between the first end and the second end. The valve  338 , such as a stopcock valve or other suitable valve, can be open or closed to allow or prevent venting of the container  10  as desired. For example, the valve  338  can be opened to vent the container  10  during the later stages of filling. Conversely, the valve  338  can be closed such as during shipping and draining. 
     The port closure  300  of the present invention provides numerous advantages, namely providing a sterile closure but still having gas-permeable properties. The sterile barrier prevents contamination. The permeable property of the closure  300  equalizes the internal pressure within the tube  302 , and therefore the container  10  that is in communication with the tube  302 , and the external pressure around the container  10 . Pressure equalization allows sterile air to enter the container  10 , which facilitates manipulation of the container  10  during handling and installation. For example, pressure equalization allows the large, flexible, collapsible container  10  to be easily manipulated while empty, without the risk of introducing non-sterile air into the container  10 . It is essential to have air in the container  10  during handling and installation, because the air acts as a lubricant allowing the container panels to move independently. However, having air in the container  10  during sterilization and shipping contributes to container bulk. Container bulk is undesirable and attempted to be minimized to the greatest extent possible. Thus, it is desirable to be able to ship the container  10  filled with fluid but with as little air as possible, and then to allow air to enter the container  10  without breaching sterility. The sterile, gas permeable port closure provides these advantages. If the second end  318  of the tube  302  is accidently dropped or introduced to contaminants, the cover member  306  maintains the second end  318  of the tube  302  and plug  304  sterile. In addition, the port closure  300  does not require injected molded ports or stainless steel couplings, thus providing cost savings. Furthermore, by using an interference fit between the tube  302  and plug  304 , no solvents are needed to connect the plug  304  to the tube  302 , therefore reducing the amount of leachables into the container  10 . 
     It is understood that, given the above description of the embodiments of the invention, various modifications may be made by one skilled in the art. Such modifications are intended to be encompassed by the claims below.