US 3514919 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
1970 I T. R. ASHTON ETAL 3,514,919
PACKAGING FLUIDS .4 Sheets-Sheet 1 Filed May 22, 1967 F IG. 3.
June 2, 1970 T. R. ASHTON ETAL 3,514,919 I PACKAGING FLUIDS 4 Sheets-Sheet 8 Filed May 22, 1967 MILK 00M All? INV 1?. J1:
June 2, 1970 T. R. ASHTON ETAL 3,514,919
PACKAGING FLUIDS Filed May 22, 1967 .4 Sheets-Sheet 5 A rra 4 ME Y5 United States Patent 3,514,919 PACKAGING FLUIDS Thomas Richard Ashton, Bromley, and Victor Claude Herbert Cottle and David Jackson, London, England, assiguors to Express Dairy Company (London) Limited, London, England, a British company, and Reed Corrugated Cases, Limited, London, England, a British company Filed May 22, 1967, Ser. No. 640,258 Claims priority, application Great Britain, May 23, 1966, 22,884/ 66; Aug. 10, 1966, 35,713/ 66 Int. Cl. B65b 51/30, 55/06, 55/14 US. Cl. 53-21 2 Claims ABSTRACT OF THE DISCLOSURE There is disclosed methods of filling presterilized containers aseptically with a sterilized fluid. Each container has a filling pipe which is initially sealed or closed at its outer end with the container in an empty flattened state in which it is sterilized at least internally. The filling pipe is clamped closed near to its outer end and the outer end is then opened and attached to a filling nozzle. Sterilizing medium is then introduced into the outer end of the filling pipe. The temporary clamp is opened and the sterilized fluid filled into the container. Part of the pipe or container includes a portion of heat sealable plastics material which is then heat sealed to seal the container and to isolate the container from the filling pipe. Several forms of filling pipe are disclosed together with forms of apparatus suitable for use in filling containers with such filling P P BACKGROUND OF THE INVENTION The inpresent invention relates to packaging and is more particularly concerned with packages for containing fluids and methods and apparatus for filling and closing such pack-ages.
It has already been proposed to convey a liquid in the form of sachet or flexible bag of a plastic material to a dispensing machine. This proposal has been applied especially for the transport and dispensing of milk, though it is, of course, applicable to other liquids, whether consumable or otherwise. In one proposal a flexible container of bag of plastic material is provided with a pipe extending from one corner. This pipe is of rubber and is attached to the bag by a surrounding metal binding ring which clamps the bag against the pipe and the pipe against a rigid tubular insert. After filling, the end of the rubber pipe is sealed by a plug. The container or bag is inserted in a dispensing machine with the filling pipe directed downwardly and outwardly and access to the contents is obtained by cutting oif the plug. Since the size of the rubber pipe is more appropriate to a relatively long duration discharge of the contents of the bag, considerable time is involved in filling the container through the same pipe. There is now a need for a container to be adapted to receive a charge of sterilized milk; to this end the container and the pipe used for filling or emptying of the container should be brought into and maintained in an aseptic condition before, during and after filling, and during emptying, at least on those surfaces which come into contact with the milk, and this is not readily attainable if a rubber pipe attached to the container is used for filling and if a separate sealing plug must be inserted thereafter in the end of the pipe.
SUMMARY OF THE INVENTION According to one feature of the present invention a method of filling a fluid into a container through a pipe 3,514,919 Patented June 2, 1970 including at least a portion of flexible material and communicating with the inside thereof and having its outer end initially sealed or closed, which include at least a portion of heat sealable plastics material comprises temporarily clamping the pipe to close it at a region between its junction with the container and its outer end, opening the outer end of the pipe and attaching it to a filling device, applying a sterilizing medium to the inside of the filling device so as to sterilize the filling device and the inside of the pipe between the filling device and where it is clamped, releasing the temporary clamp, filling the fluid into the container, and heat sealing across the portion of heat sealable plastic material to isolate the inside of the container fromthe filling device.
The container with its pipe sealed at the outer end is preferably sterilized before the filling operation and the fluid is to be filled into it is preferably a sterilized fluid.
The container, provided with a pipe, is preferably in the form of a bag of flexible plastic material, and its pipe is sealed wtih the bag in an empty, flattened or collapsed state and the whole then sterilised.
The initial sealing of the pipe and the sterilising of the bag can be done quite independently of the filling and not necessarly at the same time or place and presterilized containers can be filled aseptically by the method or apparatus of the present invention.
The pipe which will hereinafter be referred to as the filing pipe may be entirely of heat sealable plastic mater1- After heat sealing the pipe after filling the bag with sterilized fluid the inside of the filling device and of the part of the pipe from the filling device to the heat seal can, if desired, be flushed with a view to avoiding or at least reducing spillage of sterilized fluid, and then the outer end of the pipe is detached from the filling device and may be left as an extension of the now sealed and shortened pipe, or wholly or partly cut off. Preferably, however, the pipe is heat sealed at two adjacent locations and is severed in between them, thereby disconnecting the filled bag from the filling device without damaging the pipe between one heat seal and the bag and leaving a sealed part of the pipe still attached to the filling device. This, together with the filling device, can if desired, be flushed prior to detaching it from the filling device. For flushing, a stream of flushing medium such as water can be introduced into the filling device at one location and flushed away liquid removed at another location.
The sterilizing medium may be at a superatmospheric pressure and/ or at a super-ambient temperature and in order to avoid distortion of or damage to the pipe arisingfrom the temperature and/or pressure of the sterilizing medium applied to the inside of the pipe, it is preferable for the sterilizing medium to be applied to the outside of the pipe at the same time. For this purpose the sealed outer end of the pipe can be introduced into a control zone in which the filling device can be constrained, the temporary clamping of the pipe elfected in the region of the point of entry of the pipe into the control zone, and the sterilizing medium applied to the control zone at the same time as it is applied to the inside of the filling device and the pipe and so at least reduce the pressure differential across the wall of the pipe. One suitable sterilizing medium is steam and the temperature and pressure must be compatible with the material of the pipe and the duration of its application is dependent in part upon its temperature.
According to another feature of the present invention apparatus for filling a container having a pipe including at least a portion of flexible material communicating with the inside thereof which include at least a portion of heat sealable plastics material, comprises a filling device means for clamping the pipe to close it at a region spaced from the filling device, means for clamping the outer end of the pipe to the filling device, valve means for connecting the filling device selectively to a source of sterilizing medium for sterilizing the inside of the filling device and the inside of part of the pipe and to a source of filling liquid for filling the container, and means for heat sealing the heat sealable portion.
The bag may be conveniently manufactured from continuously extruded plastic tubing by spaced transverse heat seals and may preferably be contained within an outer wrapping or bag of the same or other plastic material. It is preferably formed by wrapping strip material round the bag, overlapping the marginal edges of the strip and heat sealing them longitudinally. The bag may, if desired, be provided with separate filling and emptying pipes or a single pipe may suffice both for filling and emptying. Where separate pipes are provided the filling pipe is preferably of sufficient size as to enable the bag to be filled with reasonable speed whilst the emptying pipe need only be of a size compatible with the envisaged rate of discharge of milk from the bag, and can be of rubber with a rigid tube insert at the region of its junction with the bag so that it can be attached by way of a metal binding ring, and its outer end can be closed by a plug.
After forming the bag with the filling pipe heat sealed to the bag or otherwise attached to and interconnected With the bag, and with the emptying pipe, if provided heat sealed or otherwise attached thereto, the outer end of the filling pipe is closed, and the emptying pipe, if provided, is plugged or sealed, whilst the container or bag is still empty. The inside of the bag and the outside of the bag and the inside of the outer wrapper, as Well as the inside of the filling pipe, and the inside of the emptying pipe, if provided may then be rendered aseptic in a suitable manner, such as by subjecting them to a, 8-, 'y-, X-, or possibly ultra-violet radiation.
The inner container can now be filled as described with sterilized liquid in such a manner that the container, when filled and sealed, may at least so far as its inside surfaces are concerned, still be in an aseptic condition.
For the sake of convenience, the pipe through which the bag is filled, whether it is also used for emptying the bag or a separate emptying pipe is provided, will hereinafter be referred to as the filling pipe.
A method of the present invention can therefore be applied to aseptically filling a sterilized fluid into a presterilized container in the form of a bag of flexible plastic material with a filling pipe of deformable, preferably heat resistant material, having its outer end closed and being sealingly connected to a tubular element of heat sealable material which is sealedly in communication with the inside of the bag.
The outer end portion of the filling pipe may be of deformable, preferably heat resistant, material sealingly communicating with the inside of the container through an element of heat sealable material and having its outer end initially closed by a puncturable diaphragm, and the method of filling comprises passing the closed outer end of the filling pipe in the region of its entry into a control zone temporarily clamping the filling pipe into a control zone within which a filling device is capable of being constrained, introducing a sterilizing medium into the control zone and into the inside of the filling device, establishing relative movement between the filling device and the outer end of the filling pipe to cause the filling device to engage and pierce the diaphragm at the outer end of the filling pipe, releasing the temporary clamp, filling fluid into the container, and then heat sealing said element to seal the filling container and isolate it from the filling pipe.
The tubular element of heat sealable material may itself be part of the container, especially if the container is wholly or Partly of heat sealable material and thus integral therewith, or may be attached and sealed to the container to form an extension therefrom.
If the container, at least in that part thereof which is attached to the filling pipe, is of heat sealable material, the filled container can be sealed by means of a heat seal in the region of the attachment of the filling pipe. Such heat seal can be effected in the body of the container itself or can be effected in an extension of the body of container and to which the filling pipe is attached, but in any case such heat serves two purposes, first to seal the filled container and second to isolate the filling pipe from the container.
The container with its filling pipe closed at its outer end is preferably sterilized before the filling operation and the fluid to be filled into it is preferably a sterilized fluid.
One suitable sterilizing medium is steam; other sterilizing media, either gaseous or liquid can be used though in some cases provision may have to be made for purging the inside of the filling device and of the filling pipe before filling the container or bag with sterilized fluid. When steam is used as sterilizing medium some condensate will be left inside the filling pipe and in many cases this will be of negligible quantity, for example the amount of condensate might be as little as 5 millilitres which is small as compared with the total volume of sterilized liquid in the container or bag which might be for example five gallons. However, the condensate can be removed or at least reduced in quantity by purging the inside of the filling device and of the filling pipe with sterilized air or by connecting the inside of the filling device and of the filling pipe to a source of vacuum. If a liquid sterilizing medium is used it is preferable thereafter to flush the inside of the filling device and of the filling pipe with sterilized water and then to purge them with air and/ or to connect them to a source of vacuum to suck out any remaining water. If a gaseous sterilizing medium, such as chlorine dioxide, is used, the insides of the filling device and filling pipe are preferably purged with sterilized air prior to the filling operation.
Where it is necessary that the sterilizing medium be applied to the outside of part of the pipe at the same time as it is applied to the inside of that part, at least part of the filling device is constrained within a sealable vessel provided with an opening through which the end of the pipe can be introduced, and which is at least in part defined by the pipe clamping means, and with valve means for connecting the inside of the vessel to the source of sterilizing medium.
It is envisaged that, to support the filling pipe, a semirigid tubular insert may be utilized. The tubular insert will be semirigid, and pressure and temperature resistant.
The filling pipe may be of natural or synthetic rubber or other nonheat sealable, preferably heat resistant, de-
formable material and may be attached to or connected to the container by means such as a metal binding ring which clamps together part of the container, one end portion of the filling pipe and a rigid tubular insert.
It is also envisaged that the outer end of the filling pipe may have a wall section of sufiicient thickness as to impart enough rigidity to it as to enable the outer end to be closed by a relatively thin puncturable diaphragm of for example rubber, and that the end of the filling pipe could be eifectively opened by such diaphragm being pierced by the end of the filling device. If the diaphragm can withstand the pressure and/or temperature of the sterilizing medium, the sterilizing medium need not be introduced into the inside of the filling pipe since the closed end thereof need not be pierced until after the filling device has been sterilized; it is nevertheless desirable for the filling device to be constrained within the control zone and for the sterilizing medium to be introduced into the control zone as well as into the inside of the filling device so that the outside of at least that part of the filling device which Will enter the filling pipe after the diaphragm has been pierced can be sterilized. If the diaphragm cannot safely withstand the pressure and/or temperature of the sterilizing medium, it can be pierced prior to the admission of the sterilizing medium into the control zone and into the inside of the filling device. The insert should be of pressure and temperature resistant material and the heat sealable material of the filling pipe outside the insert should be kept cool.
After heat sealing, the filling pipe can be detached from the remainder of the container, and the filling pipe and rigid insert unclamped and if desired used again. The filling pipe can be attached to one side or edge of the container, though if the container is generally cubical in shape when filled, it is convenient for the filling pipe to be attached to a corner region of the container as this greatly facilitates heat sealing after filling. Again the container need not be wholly of a heat sealable material, though that is preferable, provided that it has a portion of heat sealable material which can be clamped by means of a surrounding metal ring and a rigid insert, or by other suitable means, to the filling pipe and which can be closed by heat sealing after the container has been filled. Thus even a container wholly of heat sealable material may be provided with a hollow extension sealed to or integral with the container and communicating with the inside of the container for attachment to the filling pipe.
By way of example, one form of apparatus for filling a bag comprises an openable and sealable vessel having on one wall a filling pipe entry aperture adjacent to and contiguous with which are located filling pipe clamping means; filling pipe sealing means are disposed adjacent the clamping means; a filling nozzle extends through another wall of the vessel. The inner end of the filling nozzle may be tapered on its outer surface to facilitate its entry into the filling pipe of a bag and it may be surrounded by a taper bored clamping ring movable axially relatively to the filling nozzle by means externally of the vessel. An inlet pipe at or near the top of the vessel communicates with a supply of a sterilizing medium such as steam and a drain pipe at the bottom of the vessel communicates a trap. A flushing pipe is disposed inside the filling nozzle and communicates with a supply of flushing fluid such as water and also with the supply of sterilizing medium through a non-return valve. The filling nozzle communicates with a supply of filling liquid such as sterilized milk through a control valve upstream of the point of entry of the flushing pipe and in order that the inside of the filling nozzle can be flushed an outlet connection communicating with a drain through a trap and a valve is provided downstream of and adjacent to the liquid supply valve.
BRIEF DESCRIPTION OF DRAWINGS The invention will be further described by way of example with reference to the accompanying drawings in which:
FIG. 1 is a side view of one suitable form of container for filling sterilized fluid; 7
FIG. 2 is a vertical section illustrating diagrammatically one form of apparatus for filling a container;
FIG. 3 is a detail section along the line 33 of FIG. 2, and
FIG. 4 is a detail section along the line 44 of FIG. 2.
FIG. 5 is a cross-section of an embodiment of a filling tube for a container, 3. semi-rigid tubular insert being attached by a wire tie to the filling tube and sealed by a plug or cork.
FIG. 6 is a cross-section of another embodiment of a filling tube for a container, the walls of the filling tube being semi-rigid and the tube being sealed by a puncturab-le diaphragm.
FIG. 7 is a diagrammatic view of the apparatus used for clamping and puncturing the sealing diaphragm of the filling tube illustrated in FIG. 6, the filling nozzle having a cutting edge for puncturing the filling tube sealing diaphragm.
DESCRIPTION OF THE PREFERRED EMBODIMENTS One suitable form of container for filling aseptically with a sterilized liquid is illustrated in FIG. 1 and comprises an inner bag 10 manufactured from a continuously extruded tube of flexible heat sealable plastic material such as, for example, polyethylene or polypropylene, by providing upper and lower heat seals 12, 14. The inner bag is disposed within an outer wrapping formed from strip material of flexible heat sealable plastic material, which may or may not be the same as that from which the inner bag is formed, wrapped round with its marginal edge portions overlapping as at 16 and joined to one another by heat sealing and closed by spaced transverse heat seals 18, 20. A filling pipe 26 of flexible heat sealable plastic material, which may or may not be the same as that from which the inner bag 10 is formed, is inserted into part of the inner bag 10 and is heat sealed thereto as at 28, and the outer end of the filling pipe 26 is closed by heat sealing at 30. The pipe 26 may be used both for filling and emptying the inner bag 10, though if desired a separate emptying pipe 22 may be attached to another part of the inner bag 10. Such pipe 22 may be of flexible heat sealable plastic material, which may or may not be the same as the material of which the inner bag 10 is formed, and be heat sealed to the inner bag 10 and have its outer end closed by heat sealing or it may be of rubber and be clamped within the inner bag 10 by a binding ring 23 clamping the bag to the rubber pipe and the pipe against a rigid tubular insert 24, and have its outer end closed by a plug stopper 25 which can be subsequently removed for the purpose of dispensing liquid from within the container With the container empty and the filling pipe 26, or both the filling pipe 26 and the emptying pipe 22, if provided, closed, the inside surfaces of at least the inner bag 10 and the pipe 26 or pipes 22 and 26 are sterilized by submitting the container to suitable radiation, such as w, 5-, "y, X-, or possible ultraviolet radiation.
One suitable form of apparatus for filling a sterilized bag is illustrated in FIGS. 2, 3 or 4 and comprises a vessel which may be of generally cylindrical form having a cylindrical vertical wall 42 sealed to a bottom plate 44 and closed by a movable lid 46 hinged to the cylindrical wall 42 by a hinge 48 and clamped thereto by a bolt and win-g nut clamp 50-. The bottom plate 44 is provided with an aperture 52 through which the filling pipe 26 of a bag can be inserted. Below the aperture 52 there is mounted clamping means indicated generally at 54 and below which there is disposed a sealing and severing device 56. A filling nozzle 58 is sealed to the lid 46 at 59 and extends into the inside of the vessel 40, the lower end of the filling nozzle 58 is outwardly tapered as at 60 and a clamping ring 62 having a correspondingly tapered bore 64 is movable axially of the filling nozzle 58 by a pair of rods 66 extending through seal packings 67 in the lid 46 and attached to a cam follower plate 68 co-operating with a manually operable cam 70. The upper end of the filling nozzle 58 communicates with a sterilized milk supply 72 through a manually operable supply valve 75. A flushing pipe 76 is contained within the filling nozzle 58 and emerges downstream of the valve 74 and communicates with a supply 78 of flushing fluid such as water through a flushing valve 80, and also through a non-return valve 82 and a sterilizing valve 84 with a source of sterilizing fluid such as steam. The pipe 76 enters through the body of the supply valve 74, and a small diameter hole 77 is drilled through the wall of the pipe 76 near the inside of the valve body so that when sterilizing fluid or flushing fluid is supplied to the pipe 76 some of the fluid can be directed towards the closure member and seating of the valve 76 with a view to avoiding an unsterilized pocket 79 just downstream of the valve seating. The lid 46 also carries a sterilizing fluid inlet 88 leading to downstream of the sterilizing valve 84. A pipe connection 90 communicating with the inside of the body 75 of valve 74 through a hole 93 just downstream of its seating leads to drain through a valve 91 and a trap 92. A pipe connection 94 in the bottom plate 44 of the vessel 40 leads to drain through a trap 96.
The clamping device 54 comprises a cylindrically bored body member 100; one end of the bore is closed by a clamping member 102 having at its inner end surface a dished portion 104. Slidably within the cylindrical bore is a plunger member 106 carrying at its inner surface a clamping pad 108, conveniently of rubber, shaped complementarily to at least a part of the dished portion 104. Plunger member 106 is connected to a spring-loaded pneumatic piston and cylinder mechanism 110 which may be connected to a source of compressed air 112 or to exhaust 114 through a clamping control valve 116. The body 100 is provided with a transverse aperture 118 which may be conveniently of square shape as may be seen more particularly in FIGS. 3 and 4 for the passage of a filling pipe 26, as indicated by the broken lines in FIGS. 3 and 4. The plunger 106 is movable axially by the piston and cylinder mechanism 110 from an unclamping or released position, indicated by the broken line 106 is movable axially by the piston and cylinder mechanism 110 from an unclamping or released position, indicated by the broken line 106A, towards the clamping member 102.
The heat sealing device 56 comprises a pair of fixed heat seal members 120, 122 with an anvil 124 therebetween, and a pair of movable heat sealing members 126, 128 with a cutter 130 therebetween mounted on a plunger 132 slidable within a bore 134. The cutter 130 is normally retracted relatively to the members 126, 128 and is connected to one end of a rod 135 leading to a spring-loaded pnuematic piston and cylinder mechanism 136 which may be connected to the source of compressed air 112 or to exhaust 114 through a sealing control valve 138. The plunger 132 is connected to the rod 135 through a spring loaded lost motion connection 137 such that when the rod 135 is driven to the left by the piston and cylinder mechanism 136 the plunger 132 advances to the left to bring the members 126 and 128 into heat sealing relationship with the fixed members 120 and 122. With further movement of the members 126 and 128 restrained, rod 135 advances the cutter 130 from its retracted position relatively to the members 126 and 128, to co-operate with the anvil 124 and sever the pipe between the two heat seals formed by members 120 and 126 and 122 and 128 respectively.
For the purpose of filling a bag sterilized by radiation, the valves 74, 80, 84 and 91 are closed initially and the valves 116, 138 operated to connect their associated piston and cylinder mechanisms to exhaust. The vessel 40 can now be opened by releasing the clamp 50 and swinging the lid open. The sealed filling pipe 26 of a bag is now inserted vertically upward through the sealing device 56 and the clamping means 54 and the aperture 52 into the inside of the vessel 40. The bag is suitably supported by means not shown and the valve 116 is operated to apply compressed air to the piston and cylinder mechanism 110 so that the plunger 106 advances towards the clamping member 108 and clamps the filling pipe 26 as illustrated in the sectional View of FIG. 2, thereby effectively sealing the inside of the portion of the filling pipe which communicates with the inside of the inner bag. The seal 30 at the end of the filling pipe 26 is now cut off or the end of the pipe is otherwise opened such that the filling nozzle 58 can be inserted therein. The cam 70 is operated manually by handle 71 to clamp the end of the filling pipe to the end of the filling nozzle 58. The lid 46 is now closed and clamped to the cylindrical wall 8 42 to seal the container 40. When the lid 46 is closed and clamped, and the plunger 106 is in the clamping position as illustrated, the vessel 40 is effectively sealed and pressure resistant.
The valve 84 is then operated to admit steam as sterilizing fluid into the inside of the container 40 through the inlet pipe 88 and through the non-return valve 82 and the flushing pipe 76 into the inside of the filling nozzle 58 and the inside of the filling tube 26 above the clamping device 54. The temperature and pressure of the steam and the time of its admission are largely determined by the properties of the material of which the filling pipe 26 is made. Suitable temperatures are between and 135 C. and suitable times range from 30 minutes to a few seconds; the time and temperature being largely dependent upon the melting point of the material of the filling tube 26. By way of example, in the case of a filling tube being made from high density polyethylene, the conditions may range from a temperature of 115 C. for 30 minutes, through C. for two minutes, to a temperature of C. for a few seconds. The valve 84 is then closed and the valve 116 operated to connect the piston and cylinder mechanism 110 to exhaust 114 to unclamp the filling pipe 26 and place the filling nozzle 58 into communication with the inside of the inner bag.
The apparatus disclosed in and described with reference to FIGS. 2, 3 and 4 of the drawings in the accompanying specification can be readily modified to permit the use of sterilizing media other than steam and/or of purging media such as sterilized water and/or sterilized air. The valve 84 can be replaced by a multi-way valve for selecting the sterilizing medium or purging medium and individual control valves provided for the supply of each medium. For applying vacuum to the insides of the filling device and of the filling pipe, the flushing pipe 76 can be connected to a source of vacuum through a vacuum control valve; such source of vacuum would also apply suction to the inside of the vessel 40 and if this is not desired the non-return valve 82 would be replaced by a stopvalve which would be closed prior to opening of the vacuum control valve and would also be closed when the flushing valve 80 is opened. As the filling pipe is deformable any remaining condensate can be readily removed by suction applied to the flushing pipe 76; as the filling pipe is at this time temporarily clamped in the clamping device 54, the condensate will tend to collect in the filling pipe just above Where it is clamped and the application of suction to the flushing pipe 76 will cause the filling pipe to become flattened from the clamping region upwards, thereby forcing the condensate upwards toward the filling nozzle 58 and towards the bottom of the flushing pipe 76 which should extend downwardly as far as possible to or even beyond the bottom of the filling nozzle 58 and may be provided with a perforated region at its lower end. The removal of condensate by means of suction, though greatly facilitated when the filling pipe is of heat sealable material, is not precluded by the use of filling pipes of other deformable material; if necessary the flushing pipe 76 can be of telescopic construction so that its lower end can be extended below the lower end of the filling nozzle 58.
Where the sterilizing medium is under superatmospheric pressure it is preferable for it to be applied to the con trol zone provided by the vessel 40 before it is applied to the inside of the filling nozzle 58 and thereby to the inside of the filling pipe, so as to avoid deformation of or damage to the filling pipe particularly if it is of heat sealable material. To this end a throttle valve controlled by a pressure-sensitive device responsive to the pressure inside the vessel '40 may be provided in the pipe supplying sterilizing medium to the flushing pipe 76.
The valve 74 and clamp 54 are then opened to allow milk to fiow through the filling nozzle 58 into the inside of the container. Milk is allowed to flow until the desired quantity is in the inner bag. At this time the filling pipe 26 will also be full. The valve 138 is then operated to connect piston and cylinder mechanism 136 to the compressed air supply 112 whereby to advance the plunger 132 to cause two transverse heat seals to be effected in the filling pipe 26 and then to cause the cutter 130 to cut the pipe between the two seals. The valve 138 may then be re operated to release piston and cylinder mechanism 136 and retract the plunger 132, whereupon the filled and sealed bag may be removed for subsequent use. By opening the valves 80 and 91, a flushing fluid such as water can be introduced into the inside of the filling nozzle 58 through the flushing pipe 76 so that the contents of the filling nozzle 58 and of the remaining part of the filling pipe 26 can be flushed away through pipe 90 to drain. Valves 80 and 91 are then closed, the handle 71 operated to release the clamping collar 62 the clamp 50 released and the lid 46 opened, the end of the filling pipe 26 can then be removed from the end of the filling nozzle '58 which is then ready to receive the end of the filling tube of another bag.
The fluid capacity of the inner bag may vary within a wide range and it is envisaged that diflerent sizes of container may be used from, for example, a relatively small one having a capacity of half a gallon to a relatively large one having a capacity of, say, 5, or more gallons.
Though a separate filling pipe 26 and a separate empty ing pipe 22 are illustrated in FIGS. 1 and 2 of the accompanying drawings, it is not essential to provide separate filling and emptying pipes. Whilst the filling pipe can be of larger internal diameter, for example in the region of 1" or more, than that of a conventional discharge pipe in order that the filling operation can be eflected relatively speedily, this need not be a disadvantage even if no separate emptying pipe is provided as a suitable adaptor, or restriction can, if necessary, be incorporated in circuit with the filling pipe whilst the bag is being emptied.
The form of container illustrated in FIG. 1 is only by way of example and not restrictive. For example, the position of the filling pipe, and of the emptying pipe if provided, may be varied and either or both may be provided at any corner, at the top or at the bottom, at either side or at any position on any face of the inner bag. The outer wrapping need not have its overlapping marginal side portions located centrally of one face of the inner bag; they may be located at one side, and moreover the sides of the strip from which the wrapping is formed may be butt welded to one another and the joint between them located along one face or at one side of the inner bag or may be formed from two strips as convenient. Furthermore, the inner bag and/or the outer wrapping may be made from laminated material with two or more plies including one ply of metal foil or of an impervious plastic material.
A container may be formed with a bag of a relatively low melting point flexible plastic material provided with a filling pipe of relatively high melting point plastic mate rial, though such materials should preferably be compatible with respect to joining them to one another by heat sealing.
The apparatus illustrated in FIGS. 2, 3 and 4 is by way of example only and may be modified or adapted to permit automatic operation. For example, the valves 74, 80, 84, 91, 116 and 138 and the cam 70 may be brought under the control of a sequence control which may include one or more timing devices and/ or temperature and pressure sensitive means and/or weight or volume sensitive devices for controlling the transition from one step to another in the filling of a bag.
In addition, the clamp 50 and the lid 46 may be power operated so that the vessel 40 can be opened and closed automatically under the control of the sequence control.
Furthermore, means other than the combined heat sealing and severing device 56 may be employed. For example, heat sealing device for making a single seal may be provided and may be adapted to eflect a heat seal of sufficient length along the filling pipe such as that the pipe can be subsequently severed within the length of such heat seal. Yet again, such single heat sealing device may be used to effect two heat seals at spaced positions along the filling pipe with movement of the pipe relatively thereto between making the first and second seals. Means other than the cutter 130, such as a heated wire, may be employed for severing the filling pipe.
It is not essential for the filling nozzle 58 to be attached to the lid 46 of the vessel 40 as it can equally well extend through the side of the vessel, nor is it essential for the axis of the filling nozzle or of the vessel 40 to be vertical and either axis can be horizontal or at any convenient angle. The clamping means 54 can, if desired, be disposed inside the vessel 40.
When the filling pipe has at its outer end portion a wall thickness suffieient to impart suflicient rigidity to it and is of a heat resistant material, whether the filling pipe has its outer end initially closed by a puncturable diaphragm or by any other means such as a plug, or is sealed, it may be possible to dispose with the control ZOne provided by the vessel 40 and yet sterilize the inside of the filling nozzle and fill a sterilized fluid aseptically into a presterilized container. In the modified apparatus illustrated in FIG. 8 there is provided a block 62A similar to the clamping means 62 of FIGS. 2-4 adjacent and connected to the clamping device 54 and including means 70 for establishing relative movement between the filling nozzle 58 and the block and clamping device jointly. In operation, the outer end of the filling pipe closed by the puncturable diaphragm is inserted through the clamping device and extends into, through, and if necessary beyond the block; the clamping device is now operated to close and grip the filling pipe. If the outer end of the filling pipe is closed by a plug or other means other than a puncturable diaphragm, means may be included on or in the upper part of the block to cut 0E the top of the pipe, if the outer end of the filling pipe is closed by a puncturable diaphragm such means is not necessary. Relative movement between the clamping device and block on the one hand, and the filling device or nozzle on the other hand, can now be established in a direction axially of the filling nozzle so as to cause the filling nozzle to puncture the diaphragm if necessary and to engage the outer end of the filling pipe; the block may be provided with an inverted frusto-conical aperture at its upper end to cooperate with a frusto-conical lower end of the filling nozzle so that the outer end of the filling pipe can be sealingly clamped between the filling nozzle and the block. Sterilizing medium can now be introduced into the inside of the filling nozzle and thereby into the inside of the filling pipe, such sterilizing medium being under superatmospheric pressure and super-ambient temperature, though not at a temperature greater than that which can be safely withstood by the material of the filling pipe, yet sufliciently high to raise the outside of the filling nozzle to a sterilization temperature by heat conduction through the filling nozzle. Steam is eminently suitable for use as sterilizing medium in this manner. After sterilization has been effected, the supply of sterilizing medium is discontinued, the insides of the filling nozzle and filling pipe flushed, purged, or evacuated as described above if desired, the clamping device released to open the filling pipe, and the bag filled with sterilized fluid as previously described.
If desired, the block may be provided with heating means such as an annular cavity and means for the supply and return of a heating medium, conveniently the sterilizing medium when that is steam; alternately the block may be contained within a vessel similar to the vessel 40 and to which a heating medium can be supplied so that the block becomes heated during the sterilization which can thereby be accelerated.
The filling nozzle may be modified to enable it to pierce the sealed end of a filling pipe, For example, a rigid tubular insert can be included in the outer end portion of the filling pipe adjacent its sealed end so that the sealed end extends across one end of the tubular insert and can be pierced by the end of the filling nozzle upon the establishment of relative motion axially between the filling nozzle and the sealed end of the filling pipe. For this purpose additional clamping means may be provided inside the vessel 40 and controlled externally thereof to clampingly engage the filling pipe against its tubular insert and either or both the filling nozzle and the additional clamping means may be movable axially relatively to one another within the vessel 40 for the purpose, firstly, of causing the filling nozzle to pierce the sealed end of the filling pipe and become efiectively in sealing contact therewith prior to the admission of sterilizing fluid, and, secondly, of withdrawing the remaining end of the filling pipe from the filling nozzle after flushing. In this manner the necessity of opening the lid 46 of the vessel 40 may be obviated.
The filling pipe can be of many convenient configurations, two other embodiments being illustrated in FIGS. 4 and 6. In FIG. 5 the semi-rigid tubular insert 151 is attached to the filling tube 26 by means of a wire tie 152; the end being sealed by a plug or cork 150. FIG. 6 illustrates the filling tube 26 being sealed by a puncturable diaphragm 153, the end of the filling tube being made of semi-rigid material 154, this being self-supporting.
FIG. 7 shows diagrammatically the apparatus used in conjunction with the filling pipe illustrated in FIG. 6. The semi-rigid section 154 of the filling tube is clamped in a block 158, the puncturable diaphragm 153 being thus in a fixed position, The filling nozzle 159 has a cutting edge 160 and by the relative axial movement of the nozzle 159 to the clamped filling tube the diaphragm 153 is punctured allowing passage of the filling nozzle 159 into the filling tube 26.
By applying the method or apparatus of the present invention to presterilized containers each with a filling pipe of or communicating with a portion of heat scalable plastic material, it is possible for such presterilized containers to be filled aseptically with sterilized fluid. If containers of adequate capacity are used, it is possible for a sterilized fluid, such as sterilized milk, as part of a bulk distribution system and on a commercial basis, to
be filled aseptically into such presterilized containers from which it can be subsequently dispensed in any convenient manner, such as in a dispensing machine.
.1. A method of filling a fluid into a container through a tube having one end communicating with the inside of the container and an opposite closed outer end, the tube being formed from deformable, flexible heat scalable plastic and material having high enough resistance to heat to withstand a temperature of a sterilizing medium introduced in the tube; the steps comprising, externally supporting the tube to withstand the absolute pressure of a sterilizing medium, temporarily clamping the tube to close it at a region between its junction with the container and its closed outer end, opening the outer end of the tube and attaching it to a filling device, introducing a sterilizing medium into the filling device to sterilize the filling device and the inside of the tube between the filling device and the temporarily clamped portion of the tube, releasing the temporary clamp on the tube, introducing the fluid in sterilized condition into the container through the tube, and heat sealing across a portion of the tube to isolate the inside of the container from the filling. device 2. A method of filling a container according to claim 1, wherein the filling tube is sealed by a puncturable diaphragm which has to be punctured prior to sterilization and filling.
References Cited UNITED STATES PATENTS 2,197,717 4/1940 Bradshaw 5321 3,016,284 1/1962 Trexler 532l 3,299,606 1/1967 Weikert 5337 3,325,033 6/1967 Wheaton 53-37 X 3,340,671 9/1967 Loo 5337 3,376,688 4/1968 Takacs 5321 3,393,491 7/1968 Burton 532l 3,422,594 1/1969 Hurschman 53-37 3,427,646 2/1969 Scholle 5337 X WAYNE A. MORSE, J R, Primary Examiner US. Cl. X.R. 53-37